CA1244914A - Control for liquid ring vacuum pumps - Google Patents
Control for liquid ring vacuum pumpsInfo
- Publication number
- CA1244914A CA1244914A CA000482134A CA482134A CA1244914A CA 1244914 A CA1244914 A CA 1244914A CA 000482134 A CA000482134 A CA 000482134A CA 482134 A CA482134 A CA 482134A CA 1244914 A CA1244914 A CA 1244914A
- Authority
- CA
- Canada
- Prior art keywords
- motor
- speed
- control device
- control
- line
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C19/00—Rotary-piston pumps with fluid ring or the like, specially adapted for elastic fluids
- F04C19/001—General arrangements, plants, flowsheets
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C19/00—Rotary-piston pumps with fluid ring or the like, specially adapted for elastic fluids
- F04C19/004—Details concerning the operating liquid, e.g. nature, separation, cooling, cleaning, control of the supply
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
- Control Of Positive-Displacement Pumps (AREA)
- Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
- Control Of Non-Positive-Displacement Pumps (AREA)
- Valves And Accessory Devices For Braking Systems (AREA)
- Non-Positive Displacement Air Blowers (AREA)
Abstract
A control system for liquid ring vacuum pumps is described. To minimize the consumption of fresh water by the pump(s) a temperature sensor is installed in the exhaust air pipe or separator of the pump(s) or in the water mains which is connected to the control unit and the switching valve in the fresh water pipe. Other sensors, such as pressure sensors and capacitance sensors may be incorporated in the system and, in addition to minimizing fresh water consumption, the suction pressure and maximum motor output power can be controlled and cavitation prevented.
Description
The invention pertains to a control system for liquid ring vacuum pumps or the like.
The suction ability of a liquid ring vacuum pump depends on the operating liquid. Where water is used as the operating liquid the suction ability of the vacuum pump can be influenced to a significant extent by adjusting the temperature of the water. In particular at high vacuum levels, the ]ower the temperature of the operating liquid, the better the results.
Therefore cooling the circulating operating liquid is necessary.
When water is used as the operating liquid, cooling is normally done by removing part of the heated liquid from the operating liquid circuit and replacing it with cool, fresh liquid from the supply line. Accordingly, the operation of a water-ring vacuum pump can consume considerable amounts of fresh water which thereby affects the operating costs.
In utilizing liquid ring vacuum pumps in a process control system it is necessary to measure certain parameters and control certain variable characteristics. In particular it is necessary to control the output variable parameters of the pumps such as capacities, pump pressures, etc. Control in the past has been accomplished by turning pumps on and off, by adjustment of throttling valves or other control devices.
~ ecause these types of controls are usually associa-ted with significant maintenance and energy costs, it has pre-viously been proposed to achieve the control tasks in modern plants on centrifugal and piston pumps by utilizing stepless or continuous control of a pump's rotative speed. Energy consump-tion is thereby minimized.
In accordance with the principles of the invention a control arrangement is provided for ~acuum systems which ~ 5037-840 utilize stepless pump speed control and in particular is adap-ted for use with liquid ring vacuum pumps.
A closed loop control is provided for controlling pressure and/or temperature in a system where one or more liquid ring vacuum pumps evacuates a recipient. The suction ability of the liquid ring vacuum pump or pumps is controlled either by speed controll operating water temperature, switching pumps on and off or by air bleeding.
In accordance with the invention, sensors are connec-ted in the control loop of a pumping system. Measurements ob-tained from the sensors are applied to a control device having one or more inputs and outputs. The control device includes chronological and logical functions stored in a programmable controller by which control of the rotating speed or power out-put of one or more pump motors is achieved. With appropriate sensors connected in the control loopl control can be provided to minimize ~resh water requirementsl provide constant or tem-porarily variable suction pressure, prevent cavitation, control the maximum motor output powerl or control the on and off con-dition of several pumps.
When a separator is not used in the fresh water pipe,an adjustable bypass valve and line may be used in conjunction with a switching valve to minimize the amount of fresh water required.
To provide control under conditions of constant or temporarily variable suction pressure the liquid ring temperature should be varied within defined operating limits. In this case a pressure sensor, which is adjustable to constant suction pres-sure can he installed in the suction (vacuum) pipe of the pump or pumps. This sensor is connected to the pump motors through a control device. A speed controller is installed in thls control device to guarantee the minimum speed of the elec-tric motor to insure the stability of the liquid ring. The control device must have a frequency limit to preven-t mechanical overloading of the pump. Further in accordance with the inven-tion, an air inlet with a switching valve may be arranged in the suction pipe of the pumps. The switching valve is adjust-able to a regulated air input in the suction pipe to prevent cavitation in dependence of the temperature in the exhaust air pipe or in the separator, respectively, as well as the pressure in the suction pipe, by a control device according to a given pressure limit characteristic.
Still further in accordance with the invention, a power input sensor can also be installed in the current lead of the vacuum pump driving motor to continually control the driving motor so that through the control device and the speed control~
ler the motor always achieves its nominal power output.
The invention can be summarized, according -to a broad aspect, as a control system comprising: a suction line; an exhaust line; a ~resh liquid line; a liquid ring vacuum pump having a suction input coupled to said suction line, an exhaust output coupled to said exhaust line, a liquid input coupled to said fresh liquid line; a motor mechanically driving said pump;
one or more sensors connected in said system to measure pre-determined parameters within said system; one or more regulat-ing devices connected in said system to vary one or more respec-tive operative characteristics of said system; a programmable controller having inputs coupled to said one or more sensors and control signal outputs coupled to said one or more regulat-ing devices and to said motor, said progra~lmable controller 4~
having stored chronological and logical functions and being responsive to said stored functions and electrical sensor sig-nals generated by said one or more sensors to control the rotat-ing speed and or power output of said motor and for controlling said regulating devices; and wherein: the temperature of the -3a-liquid ring in said pump is varied within predetermined operat-ing limits stored in said programmable controller to control suction pressure in said suction line.
The invention will be better understood from a reading of the following detailed description in conjunction with the drawing in which:
Figure 1 illustrates in schematic form a vacuum~
system with liquid ring vacuum pumps without a separator; and Figure 2 illustrates in schematic form a vacuum-system with a separator.
The systems of Eigures 1 and 2 include liquid ring vacuum pumps 6, 16 connected between a suction or vacuum line or pipe 20 and an exhaust air line or pipe 21. Each vacuum pump 6, 16 is driven by an electric motor 5, 15. Although two liquid ring vacuum pumps are shown, the present invention is applicable to systems having only one or more than two liquid ring vacuum pumps.
A source of fresh water is supplied to the liquid ring vacuum pumps via fresh water line 22.
A cutoff valve 13 and a contamination filter 10 are inserted in the water line 22.
A control device 12 has input connections to various sensors to measure corresponding parameters in the system and has output connections to various parts of the system to control variable characteristics of the system. The control device 12 may be a programmable controller with functions stored therein, i.e., it may be a microprocessor controlled apparatus.
Among the sensors shown is a pressure sensor 3 con-nected in the suction line 20. Electrical connections 31 are provided between the sensor 3 and control device 12. A tempera-ture sensor 7 is connected in the exhaust air line 21 of Figure 1 or in the separator 8 of Figure 2 and has electrical connec-tions 37 to the control in the electrical supply line to the motor 5. A power sensor 55 is connected in the current lead of motor 15. Only one power sensor 55 is shown although a power sensor can also be provided for each and every motor used in the system.
A speed controller 11 is controlled by the control device 12 to establish the speed of rotation of the motor 5.
Additional speed controllers may be provided for motor 15 and any additional motors.
In the fresh water line 22 an electrically control-led valve 9 is provided which has electrical connections to the control device 12 and over which control signals are sent from the control device 12 to control the supply of fresh water to the liquid ring vacuum pumps 6, 16. In the structure of Figure 1, a bypass line 40 is connected around the valve 9. A valve 14 is provided in bypass line 40 and is ad~ustable so that a minimum quantity of fresh water is supplied to the liquid ring vacuum pumps regardless of the operative state of valve 9.
- An electrically controlled valve 1 is connected to the suction or vacuum line 20 and is controlled via electrical : connections to the control device 12. Valve 1 is used as an air bleed control valve to control the amount of air bleed into the suction or vacuum line 20.
Each of the liquid ring vacuum pumps is connected to the suction or vacuum line 20 via a throttle valve 4 which is electrically controlled by the control device 12.
As those skilled in the art will appreciate, the oper-ation of systems utilizing liquid ring vacuum pumps is u:nique because of the number of highly interrelated characteristics of operation that they have.
The three basic measurements and operative character-istics are a) the sensing of suction by the pressure sensor 3 and the control of the amount of air bleed into the system by valve l; b) the sensing of the water temperature by temperature sensor 7 and the control of the fresh water supplied to the pumps via electrically activated flow valve 9; and c~ sensing the power supplied to the motor and via sensor 55 and optimizing the energy effectiveness by decreasing the motor speed to the minimum at which the liquid ring breaks.
The control device 12 includes stored algorithms or characteristic curves so that water temperature, suction pressure and motor speed may be simultaneously set. Control device 12 will simultaneously: provide control to minimize fresh water consumption, control the suction pressure, prevent cavitation in the liquid ring and control the motor power input.
To minimize fresh water consumption in the structure of Figure 1 in which a separator is not used, the fresh water supply to the vacuum pump or pumps 6 is adjusted by the by-pass valve 14 so that a minimum quantity is delivered to maintain the water ring. ~y way of the control system the temperature sensor 7 in the exhaust air pipe, which is set proportional to the water ring temperature, the control device 12 as well as the control valve 9, the fresh water quantity can be controlled through the control of exhaust air temperature. The higher the exhaust air temperature is set, the less fresh water is required.
Where a separator is used as in Figure 2, the water temperature in the separator 8 will be kept constant by the control device 12 and the control valve 9 which are adjusted to a constant temperature by the temperature sensor 9.
In multi-pump-operation ~thether a separator is used or not, there are no additional controls necessary in the water storage pipe.
Control of constant or temporarily variable suction pressure is achieved as follows:
In the vacuum pipe in Figures 1 and 2 a pressure sensor 3 is installed in the controlled circuit, consisting of the control device 12, the electric motors 5 and the liquid ring vacuum pumps 6. This control circuit guarantees that a constant suction pressure will be maintained through the vacuum pipe independent of the gas input.
By means of a given temporary suction pressure any pressure/time-diagrams can be developed. By setting a minimum speed at the speed control 11 it is insured that the water ring remains stable. By setting a maximum frequency it is insured that the mechanical load capability of the vacuum pump will not be exceeded. Both the minimum speed and the maximum frequency may be stored in the control device 12.
To prevent cavitation in the liquid ring, in Figures 1 and 2 the valve 1 is controlled by the control device 12 independently of the temperature in the exhaust air pipe 7 as well as the pressure in the vacuum pipe 3 so that a given suc-tion pressure limit will be reached independently of the tem-perature.
The electric capacity sensor 55 in Figures 1 and 2 in connection with the control device 12, and by means of the speed control 11 insures the motor 5 will always be driven at its nominal power output.
Furthermore, control device 12 can automatically ~2~
switch pumps ~motors) on and off.
Therefore, a pump control system to switch pumps on in the event of power surges or to switch operation from one pump to another to achieve balanced pump operat:ion of several pumps is provided.
The suction ability of a liquid ring vacuum pump depends on the operating liquid. Where water is used as the operating liquid the suction ability of the vacuum pump can be influenced to a significant extent by adjusting the temperature of the water. In particular at high vacuum levels, the ]ower the temperature of the operating liquid, the better the results.
Therefore cooling the circulating operating liquid is necessary.
When water is used as the operating liquid, cooling is normally done by removing part of the heated liquid from the operating liquid circuit and replacing it with cool, fresh liquid from the supply line. Accordingly, the operation of a water-ring vacuum pump can consume considerable amounts of fresh water which thereby affects the operating costs.
In utilizing liquid ring vacuum pumps in a process control system it is necessary to measure certain parameters and control certain variable characteristics. In particular it is necessary to control the output variable parameters of the pumps such as capacities, pump pressures, etc. Control in the past has been accomplished by turning pumps on and off, by adjustment of throttling valves or other control devices.
~ ecause these types of controls are usually associa-ted with significant maintenance and energy costs, it has pre-viously been proposed to achieve the control tasks in modern plants on centrifugal and piston pumps by utilizing stepless or continuous control of a pump's rotative speed. Energy consump-tion is thereby minimized.
In accordance with the principles of the invention a control arrangement is provided for ~acuum systems which ~ 5037-840 utilize stepless pump speed control and in particular is adap-ted for use with liquid ring vacuum pumps.
A closed loop control is provided for controlling pressure and/or temperature in a system where one or more liquid ring vacuum pumps evacuates a recipient. The suction ability of the liquid ring vacuum pump or pumps is controlled either by speed controll operating water temperature, switching pumps on and off or by air bleeding.
In accordance with the invention, sensors are connec-ted in the control loop of a pumping system. Measurements ob-tained from the sensors are applied to a control device having one or more inputs and outputs. The control device includes chronological and logical functions stored in a programmable controller by which control of the rotating speed or power out-put of one or more pump motors is achieved. With appropriate sensors connected in the control loopl control can be provided to minimize ~resh water requirementsl provide constant or tem-porarily variable suction pressure, prevent cavitation, control the maximum motor output powerl or control the on and off con-dition of several pumps.
When a separator is not used in the fresh water pipe,an adjustable bypass valve and line may be used in conjunction with a switching valve to minimize the amount of fresh water required.
To provide control under conditions of constant or temporarily variable suction pressure the liquid ring temperature should be varied within defined operating limits. In this case a pressure sensor, which is adjustable to constant suction pres-sure can he installed in the suction (vacuum) pipe of the pump or pumps. This sensor is connected to the pump motors through a control device. A speed controller is installed in thls control device to guarantee the minimum speed of the elec-tric motor to insure the stability of the liquid ring. The control device must have a frequency limit to preven-t mechanical overloading of the pump. Further in accordance with the inven-tion, an air inlet with a switching valve may be arranged in the suction pipe of the pumps. The switching valve is adjust-able to a regulated air input in the suction pipe to prevent cavitation in dependence of the temperature in the exhaust air pipe or in the separator, respectively, as well as the pressure in the suction pipe, by a control device according to a given pressure limit characteristic.
Still further in accordance with the invention, a power input sensor can also be installed in the current lead of the vacuum pump driving motor to continually control the driving motor so that through the control device and the speed control~
ler the motor always achieves its nominal power output.
The invention can be summarized, according -to a broad aspect, as a control system comprising: a suction line; an exhaust line; a ~resh liquid line; a liquid ring vacuum pump having a suction input coupled to said suction line, an exhaust output coupled to said exhaust line, a liquid input coupled to said fresh liquid line; a motor mechanically driving said pump;
one or more sensors connected in said system to measure pre-determined parameters within said system; one or more regulat-ing devices connected in said system to vary one or more respec-tive operative characteristics of said system; a programmable controller having inputs coupled to said one or more sensors and control signal outputs coupled to said one or more regulat-ing devices and to said motor, said progra~lmable controller 4~
having stored chronological and logical functions and being responsive to said stored functions and electrical sensor sig-nals generated by said one or more sensors to control the rotat-ing speed and or power output of said motor and for controlling said regulating devices; and wherein: the temperature of the -3a-liquid ring in said pump is varied within predetermined operat-ing limits stored in said programmable controller to control suction pressure in said suction line.
The invention will be better understood from a reading of the following detailed description in conjunction with the drawing in which:
Figure 1 illustrates in schematic form a vacuum~
system with liquid ring vacuum pumps without a separator; and Figure 2 illustrates in schematic form a vacuum-system with a separator.
The systems of Eigures 1 and 2 include liquid ring vacuum pumps 6, 16 connected between a suction or vacuum line or pipe 20 and an exhaust air line or pipe 21. Each vacuum pump 6, 16 is driven by an electric motor 5, 15. Although two liquid ring vacuum pumps are shown, the present invention is applicable to systems having only one or more than two liquid ring vacuum pumps.
A source of fresh water is supplied to the liquid ring vacuum pumps via fresh water line 22.
A cutoff valve 13 and a contamination filter 10 are inserted in the water line 22.
A control device 12 has input connections to various sensors to measure corresponding parameters in the system and has output connections to various parts of the system to control variable characteristics of the system. The control device 12 may be a programmable controller with functions stored therein, i.e., it may be a microprocessor controlled apparatus.
Among the sensors shown is a pressure sensor 3 con-nected in the suction line 20. Electrical connections 31 are provided between the sensor 3 and control device 12. A tempera-ture sensor 7 is connected in the exhaust air line 21 of Figure 1 or in the separator 8 of Figure 2 and has electrical connec-tions 37 to the control in the electrical supply line to the motor 5. A power sensor 55 is connected in the current lead of motor 15. Only one power sensor 55 is shown although a power sensor can also be provided for each and every motor used in the system.
A speed controller 11 is controlled by the control device 12 to establish the speed of rotation of the motor 5.
Additional speed controllers may be provided for motor 15 and any additional motors.
In the fresh water line 22 an electrically control-led valve 9 is provided which has electrical connections to the control device 12 and over which control signals are sent from the control device 12 to control the supply of fresh water to the liquid ring vacuum pumps 6, 16. In the structure of Figure 1, a bypass line 40 is connected around the valve 9. A valve 14 is provided in bypass line 40 and is ad~ustable so that a minimum quantity of fresh water is supplied to the liquid ring vacuum pumps regardless of the operative state of valve 9.
- An electrically controlled valve 1 is connected to the suction or vacuum line 20 and is controlled via electrical : connections to the control device 12. Valve 1 is used as an air bleed control valve to control the amount of air bleed into the suction or vacuum line 20.
Each of the liquid ring vacuum pumps is connected to the suction or vacuum line 20 via a throttle valve 4 which is electrically controlled by the control device 12.
As those skilled in the art will appreciate, the oper-ation of systems utilizing liquid ring vacuum pumps is u:nique because of the number of highly interrelated characteristics of operation that they have.
The three basic measurements and operative character-istics are a) the sensing of suction by the pressure sensor 3 and the control of the amount of air bleed into the system by valve l; b) the sensing of the water temperature by temperature sensor 7 and the control of the fresh water supplied to the pumps via electrically activated flow valve 9; and c~ sensing the power supplied to the motor and via sensor 55 and optimizing the energy effectiveness by decreasing the motor speed to the minimum at which the liquid ring breaks.
The control device 12 includes stored algorithms or characteristic curves so that water temperature, suction pressure and motor speed may be simultaneously set. Control device 12 will simultaneously: provide control to minimize fresh water consumption, control the suction pressure, prevent cavitation in the liquid ring and control the motor power input.
To minimize fresh water consumption in the structure of Figure 1 in which a separator is not used, the fresh water supply to the vacuum pump or pumps 6 is adjusted by the by-pass valve 14 so that a minimum quantity is delivered to maintain the water ring. ~y way of the control system the temperature sensor 7 in the exhaust air pipe, which is set proportional to the water ring temperature, the control device 12 as well as the control valve 9, the fresh water quantity can be controlled through the control of exhaust air temperature. The higher the exhaust air temperature is set, the less fresh water is required.
Where a separator is used as in Figure 2, the water temperature in the separator 8 will be kept constant by the control device 12 and the control valve 9 which are adjusted to a constant temperature by the temperature sensor 9.
In multi-pump-operation ~thether a separator is used or not, there are no additional controls necessary in the water storage pipe.
Control of constant or temporarily variable suction pressure is achieved as follows:
In the vacuum pipe in Figures 1 and 2 a pressure sensor 3 is installed in the controlled circuit, consisting of the control device 12, the electric motors 5 and the liquid ring vacuum pumps 6. This control circuit guarantees that a constant suction pressure will be maintained through the vacuum pipe independent of the gas input.
By means of a given temporary suction pressure any pressure/time-diagrams can be developed. By setting a minimum speed at the speed control 11 it is insured that the water ring remains stable. By setting a maximum frequency it is insured that the mechanical load capability of the vacuum pump will not be exceeded. Both the minimum speed and the maximum frequency may be stored in the control device 12.
To prevent cavitation in the liquid ring, in Figures 1 and 2 the valve 1 is controlled by the control device 12 independently of the temperature in the exhaust air pipe 7 as well as the pressure in the vacuum pipe 3 so that a given suc-tion pressure limit will be reached independently of the tem-perature.
The electric capacity sensor 55 in Figures 1 and 2 in connection with the control device 12, and by means of the speed control 11 insures the motor 5 will always be driven at its nominal power output.
Furthermore, control device 12 can automatically ~2~
switch pumps ~motors) on and off.
Therefore, a pump control system to switch pumps on in the event of power surges or to switch operation from one pump to another to achieve balanced pump operat:ion of several pumps is provided.
Claims (42)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A control system comprising: a suction line; an ex-haust line; a fresh liquid line; a liquid ring vacuum pump having a suction input coupled to said suction line, an exhaust output coupled to said exhaust line, a liquid input coupled to said fresh liquid line; a motor mechanically driving said pump; one or more sensors connected in said system to measure predetermined parameters within said system; one or more regulat-ing devices connected in said system to vary one or more respec-tive operative characteristics of said system, a programmable controller having inputs coupled to said one or more sensors and control signal outputs coupled to said one or more regulat-ing devices and to said motor, said programmable controller having stored chronological and logical functions and being responsive to said stored functions and electrical sensor sig-nals generated by said one or more sensors to control the rotat-ing speed and or power output of said motor and for controlling said regulating devices; and wherein: the temperature of the liquid ring in said pump is varied within predetermined operat-ing limits stored in said programmable controller to control suction pressure in said suction line.
2. A control system in accordance with claim 1 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
3. A control system in accordance with claim 1 wherein:
one of said sensors comprises a pressure sensor installed in said suction line and providing pressure dependent electrical signals to said control device.
one of said sensors comprises a pressure sensor installed in said suction line and providing pressure dependent electrical signals to said control device.
4. A control system in accordance with claim 3 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
5. A control system in accordance with claim 3 wherein:
said control device including speed control means coupled to said motor to vary the rotative speed of said motor in response to said control device, said control device providing signals to said speed control means to regulate the speed of said motor whereby the motor is operated at the minimum speed necessary to insure the stability of the liquid ring.
said control device including speed control means coupled to said motor to vary the rotative speed of said motor in response to said control device, said control device providing signals to said speed control means to regulate the speed of said motor whereby the motor is operated at the minimum speed necessary to insure the stability of the liquid ring.
6. A control system in accordance with claim 5 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed control-ler for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed control-ler for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
7. A control system in accordance with claim 6 wherein:
said speed control means vary the speed of said motor by varying the frequency of the electrical signals applied thereto; said control device has stored therein frequency range limitations which prevents overloading of said pump.
said speed control means vary the speed of said motor by varying the frequency of the electrical signals applied thereto; said control device has stored therein frequency range limitations which prevents overloading of said pump.
8. A control system in accordance with claim 7 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
9. A control system comprising: a suction line; an ex-haust line; a fresh liquid line; a liquid ring vacuum pump having a suction input coupled to said suction line, an exhaust output coupled to said exhaust line, a liquid input coupled to said fresh liquid line; a motor mechanically driving said pump;
one or more sensors connected in said system to measure predeter-mined parameters within said system; one or more regulating de-vices connected in said system to vary one or more respective operative characteristics of said system; a programmable control-ler having inputs coupled to said one or more sensors and con-trol signal outputs coupled to said one or more regulating de-vices and to said motor, said programmable controller having stored chronological and logical functions and being responsive to said stored functions and electrical sensing signals generated by said one or more sensors to control the rotating speed and or power output of said motor and for controlling said regulating devices; and wherein: one of said regulating devices comprises an electrically actuable second valve connected in said suction line, said second valve being controlled by said control device to bleed air into said suction line in accordance with a pre-determined pressure limit to regulate air input in said suction line to prevent cavitation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suc-tion line.
one or more sensors connected in said system to measure predeter-mined parameters within said system; one or more regulating de-vices connected in said system to vary one or more respective operative characteristics of said system; a programmable control-ler having inputs coupled to said one or more sensors and con-trol signal outputs coupled to said one or more regulating de-vices and to said motor, said programmable controller having stored chronological and logical functions and being responsive to said stored functions and electrical sensing signals generated by said one or more sensors to control the rotating speed and or power output of said motor and for controlling said regulating devices; and wherein: one of said regulating devices comprises an electrically actuable second valve connected in said suction line, said second valve being controlled by said control device to bleed air into said suction line in accordance with a pre-determined pressure limit to regulate air input in said suction line to prevent cavitation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suc-tion line.
10. A control system comprising: a suction line; an ex-haust line; a fresh liquid line; a liquid ring vacuum pump hav-ing a suction input coupled to said suction line, an exhaust output coupled to said exhaust line, a liquid input coupled to said fresh liquid line; a motor mechanically driving said pump;
one or more sensors connected in said system to measure pre-determined parameters within said system including a temperature sensor installed in said exhaust line; one or more regulating devices connected in said system to vary one or more respective operative characteristics of said system including an electric-ally actuable first valve in said fresh liquid line; a program-mable controller having inputs coupled to said one or more sen-sors and control signal outputs coupled to said one or more regulating devices and to said motor, said programmable control-ler having stored chronological and logical functions and being responsive to said stored functions and electrical sensing sig-nals generated by said one or more sensors to control the rotat-ing speed and or power output of said motor and for controlling said one or more regulating devices; said control system being operative to minimize fresh liquid consumption by said pump; and wherein the temperature of the liquid ring in said pump is varied within predetermined operating limits stored in said programmable controller to control suction pressure in said suction line.
one or more sensors connected in said system to measure pre-determined parameters within said system including a temperature sensor installed in said exhaust line; one or more regulating devices connected in said system to vary one or more respective operative characteristics of said system including an electric-ally actuable first valve in said fresh liquid line; a program-mable controller having inputs coupled to said one or more sen-sors and control signal outputs coupled to said one or more regulating devices and to said motor, said programmable control-ler having stored chronological and logical functions and being responsive to said stored functions and electrical sensing sig-nals generated by said one or more sensors to control the rotat-ing speed and or power output of said motor and for controlling said one or more regulating devices; said control system being operative to minimize fresh liquid consumption by said pump; and wherein the temperature of the liquid ring in said pump is varied within predetermined operating limits stored in said programmable controller to control suction pressure in said suction line.
11. A control system in accordance with claim 10 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed con-troller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed con-troller so that said motor is always run at a predetermined nominal output.
12. A control system in accordance with claim 10 wherein:
one of said regulating devices comprises an electrically actu-able second valve connected in said suction line, said second valve being controlled by said control device to bleed air into said suction line in accordance with a predetermined pressure limit to regulate air input in said suction line to prevent cavi-tation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suction line.
one of said regulating devices comprises an electrically actu-able second valve connected in said suction line, said second valve being controlled by said control device to bleed air into said suction line in accordance with a predetermined pressure limit to regulate air input in said suction line to prevent cavi-tation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suction line.
13. A control system in accordance with claim 12 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
14. A control system in accordance with claim 10 wherein:
one of said sensors comprises a pressure sensor installed in said suction line and providing pressure dependent electrical signals to said control device.
one of said sensors comprises a pressure sensor installed in said suction line and providing pressure dependent electrical signals to said control device.
15. A control system in accordance with claim 14 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
16. A control system in accordance with claim 14 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
17. A control system in accordance with claim 14 wherein:
said control device including speed control means coupled to said motor to vary the rotative speed of said motor in response to said control device, said control device providing signals to said speed control means to regulate the speed of said motor whereby the motor is operated at the minimum speed necessary to insure the stability of the liquid ring.
said control device including speed control means coupled to said motor to vary the rotative speed of said motor in response to said control device, said control device providing signals to said speed control means to regulate the speed of said motor whereby the motor is operated at the minimum speed necessary to insure the stability of the liquid ring.
18. A control system in accordance with claim 17 wherein:
said speed control means vary the speed of said motor by varying the frequency of the electrical signals applied thereto; said control device has stored their frequency range limitations which prevents overloading of said pump.
said speed control means vary the speed of said motor by varying the frequency of the electrical signals applied thereto; said control device has stored their frequency range limitations which prevents overloading of said pump.
19. A control system comprising: a suction line; an ex-haust line; a fresh liquid line; a liquid ring vacuum pump hav-ing a suction input coupled to said suction line, an exhaust output coupled to said exhaust line, a liquid input coupled to said fresh liquid line; a motor mechanically driving said pump;
one or more sensors connected in said system to measure pre-determined parameters within said system including a temperature sensor installed in said exhaust line; one or more regulating devices connected in said system to vary one or more respective operative characteristics of said system including an electrical-ly actuable first valve in said fresh liquid line; a program-mable controller having inputs coupled to said one or more sen-sors and control signal outputs coupled to said one or more re-gulating devices and to said motor, said programmable controller having stored chronological and logical functions and being responsive to said stored functions and electrical sensing signals generated by said one or more sensors to control the rotating speed and or power output of said motor and for controlling said regulating devices; and wherein: one of said regulating de-vices comprises an electrically actuable second valve connected in said suction line, said second valve being controlled by said control device to bleed air into said suction line in accordance with a predetermined pressure limit to regulate air input in said suction line to prevent cavitation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suction line.
one or more sensors connected in said system to measure pre-determined parameters within said system including a temperature sensor installed in said exhaust line; one or more regulating devices connected in said system to vary one or more respective operative characteristics of said system including an electrical-ly actuable first valve in said fresh liquid line; a program-mable controller having inputs coupled to said one or more sen-sors and control signal outputs coupled to said one or more re-gulating devices and to said motor, said programmable controller having stored chronological and logical functions and being responsive to said stored functions and electrical sensing signals generated by said one or more sensors to control the rotating speed and or power output of said motor and for controlling said regulating devices; and wherein: one of said regulating de-vices comprises an electrically actuable second valve connected in said suction line, said second valve being controlled by said control device to bleed air into said suction line in accordance with a predetermined pressure limit to regulate air input in said suction line to prevent cavitation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suction line.
20. A control system in accordance with claim 19 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
21. A control system comprising: a suction line; an ex-haust line; a fresh liquid line; a liquid ring vacuum pump hav-ing a suction input coupled to said suction line, an exhaust output coupled to said exhaust line, a liquid input coupled to said fresh liquid line; a motor mechanically driving said pump;
one or more sensors connected in said system to measure predeter-mined parameters within said system; one or more regulating devices connected in said system to vary one or more respective operative characteristics of said system; a programmable control-ler having inputs coupled to said one or more sensors and control signal outputs coupled to said one or more regulating devices and to said motor, said programmable controller having stored chronological and logical functions and being responsive to said stored functions and electrical sensing signals generated by said one or more sensors to control the rotating speed and or power output of said motor and for controlling said regulating devices; and wherein: one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system com-prises a speed controller for varying the speed of said motor;
said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output; and one of said regulating devices comprises an electrically actuable second valve connected in said suction line, said second valve being controlled by said control device to bleed on into said suction line in accordance with a predetermined pressure limit to regulate air input in said suction line to prevent cavitation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suction line.
one or more sensors connected in said system to measure predeter-mined parameters within said system; one or more regulating devices connected in said system to vary one or more respective operative characteristics of said system; a programmable control-ler having inputs coupled to said one or more sensors and control signal outputs coupled to said one or more regulating devices and to said motor, said programmable controller having stored chronological and logical functions and being responsive to said stored functions and electrical sensing signals generated by said one or more sensors to control the rotating speed and or power output of said motor and for controlling said regulating devices; and wherein: one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system com-prises a speed controller for varying the speed of said motor;
said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output; and one of said regulating devices comprises an electrically actuable second valve connected in said suction line, said second valve being controlled by said control device to bleed on into said suction line in accordance with a predetermined pressure limit to regulate air input in said suction line to prevent cavitation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suction line.
22. A control system comprising: a suction line; a separ-ator; a fresh liquid line; a liquid ring vacuum pump having a suction input coupled to said suction line, an exhaust output coupled to said separator, a liquid input coupled to said fresh liquid line; a motor mechanically driving said pump; one or more sensors connected in said system to measure predetermined para-meters within said system; one or more regulating devices connec-ted in said system to vary one or more respective operative characteristics of said system; a programmable controller having inputs coupled to said one or more sensors and control signal outputs coupled to said one or more regulating devices and to said motor, said programmable controller having stored chronolo-gical and logical functions and being responsive to said stored functions and electrical sensing signals generated by said one or more sensors to control the rotating speed and or power out-put of said motor and for controlling said regulating devices;
and wherein the temperature of the liquid ring in said pump is varied within predetermined operating limits stored in said programmable controller to control suction pressure in said suction line.
and wherein the temperature of the liquid ring in said pump is varied within predetermined operating limits stored in said programmable controller to control suction pressure in said suction line.
23. A control system in accordance with claim 22 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
24. A control system in accordance with claim 22 wherein:
one of said sensors comprises a pressure sensor installed in said suction line and providing pressure dependent electrical signals to said control device.
one of said sensors comprises a pressure sensor installed in said suction line and providing pressure dependent electrical signals to said control device.
25. A control system in accordance with claim 24 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
26. A control system in accordance with claim 24 wherein:
said control device including speed control means coupled to said motor to vary the rotative speed of said motor in response to said control device, said control device providing signals to said speed control means to regulate the speed of said motor whereby the motor is operated at the minimum speed necessary to insure the stability of the liquid ring.
said control device including speed control means coupled to said motor to vary the rotative speed of said motor in response to said control device, said control device providing signals to said speed control means to regulate the speed of said motor whereby the motor is operated at the minimum speed necessary to insure the stability of the liquid ring.
27. A control system in accordance with claim 26 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
28. A control system in accordance with claim 26 wherein:
said speed control means vary the speed of said motor by vary-ing the frequency of the electrical signals applied thereto;
said control device has stored therein frequency range limita-tions which prevents overloading of said pump.
said speed control means vary the speed of said motor by vary-ing the frequency of the electrical signals applied thereto;
said control device has stored therein frequency range limita-tions which prevents overloading of said pump.
29. A control system in accordance with claim 28 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
30. A control system comprising: a suction line; a sep-arator; a fresh liquid line; a liquid ring vacuum pump having a suction input coupled to said suction line, an exhaust output coupled to said separator, a liquid input coupled to said fresh liquid line; a motor mechanically driving said pump; one or more sensors connected in said system to measure predetermined para-meters within said system; one or more regulating devices connec-ted in said system to vary one or more respective operative characteristics of said system; a programmable controller having inputs coupled to said one or more sensors and control signal outputs coupled to said one or more regulating devices and to said motor, said programmable controller having stored chrono-logical and logical functions and being responsive to said stored functions and electrical sensing signals generated by said one or more sensors to control the rotating speed and or power output of said motor and for controlling said regulating devices; and wherein: one of said regulating devices comprises an electrically actuable second valve connected in said suction line, said second valve being controlled by said control device to bleed air into said suction line in accordance with a pre-determined pressure limit to regulate air input in said suction line to prevent cavitation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suc-tion line.
31. A control system comprising: a suction line; a sep-arator; a fresh liquid line; a liquid ring vacuum pump having a suction input coupled to said suction line, an exhaust output coupled to said separator, a liquid input coupled to said fresh liquid line; a motor mechanically driving said pump; one or more sensors connected in said system to measure predetermined parameters within said system; one or more regulating devices connected in said system to vary one or more respective opera-tive characteristics of said system; a programmable controller having inputs coupled to said one or more sensors and control signal outputs coupled to said one or more regulating devices and to said motor, said programmable controller having stored chronological and logical functions and being responsive to said stored functions and electrical sensing signals generated by said one or more sensors to control the rotating speed and or power output of said motor and for controlling said regulating devices; one of said sensors comprises a temperature sensor installed in said separator; one of said regulating devices com-prises an electrically actuable first valve in said fresh liquid line; said control system being operative to minimize fresh liquid consumption by said pump; and wherein the temperature of the liquid ring in said pump is varied within predetermined operating limits stored in said programmable controller to con-trol suction pressure in said suction line.
32. A control system in accordance with claim 31 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed con-troller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed con-troller so that said motor is always run at a predetermined nominal output.
33. A control system in accordance with claim 31 wherein:
one of said regulating devices comprises an electrically actuable second valve connected in said suction line, said second valve being controlled by said control device to bleed air into said suction line in accordance with a predetermined pressure limit to regulate air input in said suction line to prevent cavitation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suction line.
one of said regulating devices comprises an electrically actuable second valve connected in said suction line, said second valve being controlled by said control device to bleed air into said suction line in accordance with a predetermined pressure limit to regulate air input in said suction line to prevent cavitation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suction line.
34. A control system in accordance with claim 33 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
35. A control system in accordance with claim 31 wherein:
one of said sensors comprises a pressure sensor installed in said suction line and providing pressure dependent electrical signals to said control device.
one of said sensors comprises a pressure sensor installed in said suction line and providing pressure dependent electrical signals to said control device.
36. A control system in accordance with claim 35 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed control-ler for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed control-ler for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
37. A control system in accordance with claim 35 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor, and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor, and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
38. A control system in accordance with claim 37 wherein:
said control device including speed control means coupled to said motor to vary the rotative speed of said motor in response to said control device, said control device providing signals to said speed control means to regulate the speed of said motor whereby the motor is operated at the minimum speed necessary to insure the stability of the liquid ring.
said control device including speed control means coupled to said motor to vary the rotative speed of said motor in response to said control device, said control device providing signals to said speed control means to regulate the speed of said motor whereby the motor is operated at the minimum speed necessary to insure the stability of the liquid ring.
39. A control system in accordance with claim 38 wherein:
said speed control means vary the speed of said motor by varying the frequency of the electrical signals applied thereto; said control device has stored their frequency range limitations which prevents overloading of said pump.
said speed control means vary the speed of said motor by varying the frequency of the electrical signals applied thereto; said control device has stored their frequency range limitations which prevents overloading of said pump.
40. A control system comprising: a suction line; a sep-arator; a fresh liquid line; a liquid ring vacuum pump having a suction input coupled to said suction line, an exhaust output coupled to said separator, a liquid input coupled to said fresh liquid line; a motor mechanically driving said pump; one or more sensors connected in said system to measure predetermined para-meters within said system; one or more regulating devices connec-ted in said system to vary one or more respective operative characteristics of said system; a programmable controller having inputs coupled to said one or more sensors and control signal outputs coupled to said one or more regulating devices and to said motor, said programmable controller having stored chrono-logical and logical functions and being responsive to said stored functions and electrical sensing signals operated by said one or more sensors to control the rotating speed and or power output of said motor and for controlling said regulating devices;
one of said sensors comprises a temperature sensor installed in said separator; one of said regulating devices comprises an electrically actuable first valve in said fresh liquid line;
said control system being operative to minimize fresh liquid consumption by said pump; and wherein: one of said regulating devices comprises an electrically actuable second valve connec-ted in said suction line, said second valve being controlled by said control device to bleed air into said suction line in ac-cordance with a predetermined pressure limit to regulate air input in said suction line to prevent cavitation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suction line.
one of said sensors comprises a temperature sensor installed in said separator; one of said regulating devices comprises an electrically actuable first valve in said fresh liquid line;
said control system being operative to minimize fresh liquid consumption by said pump; and wherein: one of said regulating devices comprises an electrically actuable second valve connec-ted in said suction line, said second valve being controlled by said control device to bleed air into said suction line in ac-cordance with a predetermined pressure limit to regulate air input in said suction line to prevent cavitation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suction line.
41. A control system in accordance with claim 40 wherein:
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output.
42. A control system comprising: a suction line; a sep-arator; a fresh liquid line; a liquid ring vacuum pump having a suction input coupled to said suction line, an exhaust output coupled to said separator, a liquid input coupled to said fresh liquid line; a motor mechanically driving said pump; one or more sensors connected in said system to measure predetermined para-meters within said system; one or more regulating devices connec-ted in said system to vary one or more respective operative characteristics of said system; a programmable controller having inputs coupled to said one or more sensors and control signal outputs coupled to said one or more regulating devices and to said motor, said programmable controller having stored chronological and logical functions and being responsive to said stored functions and electrical sensing signals generated by said one or more sensors to control the rotating speed and or power output of said motor and for controlling said regulating devices; one of said sensors comprises a power input sensor connected in the current leads to said motor and supplying power signals to said control device; said system comprises a speed controller for varying the speed of said motor; and said control device is responsive to said power signals for controlling said speed controller so that said motor is always run at a predetermined nominal output and wherein: one of said regulating devices comprises an electrically actuable second valve connec-ted in said suction line, said second valve being controlled by said control device to bleed air into said suction line in accordance with a predetermined pressure limit to regulate air input in said suction line to prevent cavitation in the liquid ring in dependence on the temperature in said exhaust line and pressure in said suction line.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19843420144 DE3420144A1 (en) | 1984-05-30 | 1984-05-30 | CONTROL AND CONTROL SYSTEM, IN PARTICULAR. FOR WATERING VACUUM PUMPS |
| DEP3420144.0 | 1984-05-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1244914A true CA1244914A (en) | 1988-11-15 |
Family
ID=6237202
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000482134A Expired CA1244914A (en) | 1984-05-30 | 1985-05-23 | Control for liquid ring vacuum pumps |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4655688A (en) |
| EP (1) | EP0169336A1 (en) |
| JP (1) | JPS611886A (en) |
| CA (1) | CA1244914A (en) |
| DE (1) | DE3420144A1 (en) |
| DK (1) | DK239085A (en) |
| NO (1) | NO852106L (en) |
Families Citing this family (75)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3425616A1 (en) * | 1984-07-12 | 1986-01-23 | Loewe Pumpenfabrik GmbH, 2120 Lüneburg | ARRANGEMENT TO MINIMIZE COOLANT CONSUMPTION IN PARTICULAR. FOR LIQUID RING VACUUM PUMPS OR THE LIKE. |
| US4699570A (en) * | 1986-03-07 | 1987-10-13 | Itt Industries, Inc | Vacuum pump system |
| JPH02180011A (en) * | 1988-12-29 | 1990-07-12 | J C C Eng Kk | Method of and apparatus for vacuum impregnation of electrolytic capacitor |
| US5008051A (en) * | 1989-03-01 | 1991-04-16 | Decoursey Robert T | Vacuum sizing tank with electronically controlled vacuum pressure |
| FR2652390B1 (en) * | 1989-09-27 | 1991-11-29 | Cit Alcatel | VACUUM PUMP GROUP. |
| DE3937152A1 (en) * | 1989-11-08 | 1991-05-16 | Gutehoffnungshuette Man | METHOD FOR OPTIMIZING OPERATION OF TWO OR SEVERAL COMPRESSORS IN PARALLEL OR SERIES |
| US5141403A (en) * | 1990-12-07 | 1992-08-25 | Cornell Research Foundation, Inc. | Two-level vacuum system controller with adjustable speed drive |
| GB2253245B (en) * | 1991-02-28 | 1994-10-19 | Hamworthy Heating Ltd | Flow related control means for a pump |
| ES2079264B1 (en) * | 1993-03-02 | 1997-12-16 | Puig Jordi Renedo | IMPROVEMENTS IN THE REGULATION OF FLUID CONDITIONING CENTRALS. |
| FR2706644B1 (en) * | 1993-06-11 | 1995-08-11 | Normalab | Vacuum regulation device. |
| US5772403A (en) * | 1996-03-27 | 1998-06-30 | Butterworth Jetting Systems, Inc. | Programmable pump monitoring and shutdown system |
| DE19715480C2 (en) * | 1997-04-14 | 1999-01-14 | Saskia Solar Und Energietechni | Vacuum pump system with a liquid ring pump |
| DE19804330A1 (en) * | 1998-02-04 | 1999-08-12 | K Busch Gmbh Druck & Vakuum Dr | Process for regulating a compressor |
| ATE285037T1 (en) * | 1998-03-19 | 2005-01-15 | Nsb Gas Proc Ag | METHOD AND SENSOR FOR DETECTING CAVITATIONS, AND DEVICE CONTAINING SUCH A SENSOR |
| US7871249B2 (en) * | 1998-04-16 | 2011-01-18 | Air Liquide Electronics U.S. Lp | Systems and methods for managing fluids using a liquid ring pump |
| US20070119816A1 (en) * | 1998-04-16 | 2007-05-31 | Urquhart Karl J | Systems and methods for reclaiming process fluids in a processing environment |
| US7980753B2 (en) | 1998-04-16 | 2011-07-19 | Air Liquide Electronics U.S. Lp | Systems and methods for managing fluids in a processing environment using a liquid ring pump and reclamation system |
| US6505475B1 (en) | 1999-08-20 | 2003-01-14 | Hudson Technologies Inc. | Method and apparatus for measuring and improving efficiency in refrigeration systems |
| US6638022B2 (en) * | 2000-01-17 | 2003-10-28 | Honda Giken Kogyo Kabushiki Kaisha | Hybrid vehicle control device |
| US6302654B1 (en) * | 2000-02-29 | 2001-10-16 | Copeland Corporation | Compressor with control and protection system |
| JP2002151449A (en) * | 2000-11-10 | 2002-05-24 | Disco Abrasive Syst Ltd | Vacuum generating mechanism in processing machine |
| JP2002168192A (en) * | 2000-12-01 | 2002-06-14 | Seiko Instruments Inc | Vacuum pump |
| US6892546B2 (en) | 2001-05-03 | 2005-05-17 | Emerson Retail Services, Inc. | System for remote refrigeration monitoring and diagnostics |
| US6668240B2 (en) * | 2001-05-03 | 2003-12-23 | Emerson Retail Services Inc. | Food quality and safety model for refrigerated food |
| US6558131B1 (en) * | 2001-06-29 | 2003-05-06 | nash-elmo industries, l.l.c. | Liquid ring pumps with automatic control of seal liquid injection |
| US6889173B2 (en) * | 2002-10-31 | 2005-05-03 | Emerson Retail Services Inc. | System for monitoring optimal equipment operating parameters |
| US8463441B2 (en) | 2002-12-09 | 2013-06-11 | Hudson Technologies, Inc. | Method and apparatus for optimizing refrigeration systems |
| MXPA06002197A (en) * | 2003-08-25 | 2006-05-22 | Computer Process Controls Inc | Refrigeration control system. |
| US20070150305A1 (en) * | 2004-02-18 | 2007-06-28 | Klaus Abraham-Fuchs | Method for selecting a potential participant for a medical study on the basis of a selection criterion |
| US7412842B2 (en) * | 2004-04-27 | 2008-08-19 | Emerson Climate Technologies, Inc. | Compressor diagnostic and protection system |
| US7275377B2 (en) | 2004-08-11 | 2007-10-02 | Lawrence Kates | Method and apparatus for monitoring refrigerant-cycle systems |
| EP1851959B1 (en) * | 2005-02-21 | 2012-04-11 | Computer Process Controls, Inc. | Enterprise control and monitoring system |
| US20070109912A1 (en) * | 2005-04-15 | 2007-05-17 | Urquhart Karl J | Liquid ring pumping and reclamation systems in a processing environment |
| US8036853B2 (en) * | 2005-04-26 | 2011-10-11 | Emerson Climate Technologies, Inc. | Compressor memory system and method |
| US8156751B2 (en) * | 2005-05-24 | 2012-04-17 | Emerson Climate Technologies, Inc. | Control and protection system for a variable capacity compressor |
| DE102005043434A1 (en) * | 2005-09-13 | 2007-03-15 | Gardner Denver Elmo Technology Gmbh | Device for adjusting the capacity of a liquid ring pump |
| US7752854B2 (en) * | 2005-10-21 | 2010-07-13 | Emerson Retail Services, Inc. | Monitoring a condenser in a refrigeration system |
| US20070089436A1 (en) * | 2005-10-21 | 2007-04-26 | Abtar Singh | Monitoring refrigerant in a refrigeration system |
| US20070089435A1 (en) * | 2005-10-21 | 2007-04-26 | Abtar Singh | Predicting maintenance in a refrigeration system |
| US7594407B2 (en) | 2005-10-21 | 2009-09-29 | Emerson Climate Technologies, Inc. | Monitoring refrigerant in a refrigeration system |
| US7665315B2 (en) * | 2005-10-21 | 2010-02-23 | Emerson Retail Services, Inc. | Proofing a refrigeration system operating state |
| US7596959B2 (en) | 2005-10-21 | 2009-10-06 | Emerson Retail Services, Inc. | Monitoring compressor performance in a refrigeration system |
| US7752853B2 (en) | 2005-10-21 | 2010-07-13 | Emerson Retail Services, Inc. | Monitoring refrigerant in a refrigeration system |
| US20070093732A1 (en) * | 2005-10-26 | 2007-04-26 | David Venturi | Vibroacoustic sound therapeutic system and method |
| US8590325B2 (en) | 2006-07-19 | 2013-11-26 | Emerson Climate Technologies, Inc. | Protection and diagnostic module for a refrigeration system |
| US20080216494A1 (en) | 2006-09-07 | 2008-09-11 | Pham Hung M | Compressor data module |
| US20090037142A1 (en) | 2007-07-30 | 2009-02-05 | Lawrence Kates | Portable method and apparatus for monitoring refrigerant-cycle systems |
| US8393169B2 (en) | 2007-09-19 | 2013-03-12 | Emerson Climate Technologies, Inc. | Refrigeration monitoring system and method |
| US9140728B2 (en) | 2007-11-02 | 2015-09-22 | Emerson Climate Technologies, Inc. | Compressor sensor module |
| US8160827B2 (en) * | 2007-11-02 | 2012-04-17 | Emerson Climate Technologies, Inc. | Compressor sensor module |
| WO2009069090A2 (en) | 2007-11-27 | 2009-06-04 | L'air Liquide-Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Improved reclaim function for semiconductor processing systems |
| CN102089481B (en) * | 2008-07-10 | 2013-12-18 | 喷射器股份有限公司 | Method for controlling vacuum generator in vacuum sewage system |
| CN102449606B (en) * | 2009-05-29 | 2015-01-21 | 爱默生零售服务公司 | System and method for monitoring and evaluating equipment operating parameter modifications |
| EP2426236B1 (en) * | 2010-09-03 | 2013-01-02 | Carbon-Clean Technologies AG | Method and fuel generation assembly for the carbon dioxide-neutral compensation of energy peaks and troughs in the generation of electrical energy and/or for producing a fuel containing hydrocarbons |
| WO2012118830A2 (en) | 2011-02-28 | 2012-09-07 | Arensmeier Jeffrey N | Residential solutions hvac monitoring and diagnosis |
| MX348628B (en) * | 2011-12-12 | 2017-06-22 | Sterling Ind Consult Gmbh | Liquid ring vacuum pump with cavitation regulation. |
| US8964338B2 (en) | 2012-01-11 | 2015-02-24 | Emerson Climate Technologies, Inc. | System and method for compressor motor protection |
| US9480177B2 (en) | 2012-07-27 | 2016-10-25 | Emerson Climate Technologies, Inc. | Compressor protection module |
| US9310439B2 (en) | 2012-09-25 | 2016-04-12 | Emerson Climate Technologies, Inc. | Compressor having a control and diagnostic module |
| US9803902B2 (en) | 2013-03-15 | 2017-10-31 | Emerson Climate Technologies, Inc. | System for refrigerant charge verification using two condenser coil temperatures |
| US9551504B2 (en) | 2013-03-15 | 2017-01-24 | Emerson Electric Co. | HVAC system remote monitoring and diagnosis |
| WO2014144446A1 (en) | 2013-03-15 | 2014-09-18 | Emerson Electric Co. | Hvac system remote monitoring and diagnosis |
| AU2014248049B2 (en) | 2013-04-05 | 2018-06-07 | Emerson Climate Technologies, Inc. | Heat-pump system with refrigerant charge diagnostics |
| JP6331078B2 (en) * | 2014-04-16 | 2018-05-30 | 三浦工業株式会社 | Pressure reducing device using water-sealed vacuum pump |
| JP2016056738A (en) * | 2014-09-10 | 2016-04-21 | 有限会社K&G | Vacuum pump system and wet type vacuum sprinkler system using the same |
| CN105649986B (en) * | 2014-11-10 | 2018-07-20 | 中国科学院沈阳科学仪器股份有限公司 | Impact-proof structure for multistage vacuum pump and the multistage vacuum pump with the structure |
| BE1024411B1 (en) * | 2016-02-23 | 2018-02-12 | Atlas Copco Airpower Naamloze Vennootschap | Method for operating a vacuum pump system and vacuum pump system applying such a method. |
| JP2017166413A (en) * | 2016-03-16 | 2017-09-21 | 三浦工業株式会社 | Operational method for water seal type vacuum pump and utilization device |
| US20160296902A1 (en) | 2016-06-17 | 2016-10-13 | Air Liquide Electronics U.S. Lp | Deterministic feedback blender |
| CN110418891A (en) * | 2017-02-24 | 2019-11-05 | 佶缔纳士机械有限公司 | Pumping system including controller |
| GB2571971B (en) * | 2018-03-14 | 2020-09-23 | Edwards Tech Vacuum Engineering Qingdao Co Ltd | Liquid ring pump control |
| GB2571970B (en) | 2018-03-14 | 2020-09-16 | Edwards Tech Vacuum Engineering (Qingdao) Co Ltd | A liquid ring pump manifold with integrated non-return valve |
| WO2020082285A1 (en) * | 2018-10-25 | 2020-04-30 | Edwards Technologies Vacuum Engineering (Qingdao) Co Ltd | Liquid ring pump control |
| JP2022516683A (en) * | 2018-10-25 | 2022-03-01 | エドワーズ テクノロジーズ バキューム エンジニアリング （チンタオ） カンパニー リミテッド | Separator system |
| GB2599160A (en) * | 2020-09-29 | 2022-03-30 | Leybold Gmbh | Method for operating a pump system |
Family Cites Families (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR548693A (en) * | 1922-03-10 | 1923-01-20 | Nash Engineering Co | Improvements in wet vacuum pumps |
| US1681574A (en) * | 1923-03-01 | 1928-08-21 | Westinghouse Air Brake Co | Rotary compressor |
| US1867813A (en) * | 1930-02-01 | 1932-07-19 | Lucian F Easton | Dual purpose pumping apparatus |
| DE697264C (en) * | 1937-09-18 | 1940-10-10 | Siemens Schuckertwerke Akt Ges | Pump with rotating liquid ring for pumping gases |
| US2230405A (en) * | 1938-04-20 | 1941-02-04 | Irving C Jennings | Pumping system |
| FR949275A (en) * | 1945-10-03 | 1949-08-25 | Suisse Construction Locomotive | Automatic commissioning device for liquid ring pump driven by a motor |
| DE968232C (en) * | 1952-06-17 | 1958-01-30 | Siemens Ag | Liquid ring vacuum pump with upstream ejector |
| US2971691A (en) * | 1955-08-16 | 1961-02-14 | Heraeus Gmbh W C | Pumping system |
| DE2217022C3 (en) * | 1972-04-08 | 1975-03-27 | Sihi Gmbh & Co Kg, 2210 Itzehoe | Liquid ring vacuum pump with circulating tank |
| DE2430314C3 (en) * | 1974-06-24 | 1982-11-25 | Siemens AG, 1000 Berlin und 8000 München | Liquid ring vacuum pump with upstream compressor |
| US3981618A (en) * | 1975-02-14 | 1976-09-21 | Grumman Aerospace Corporation | Method and apparatus for preventing pump cavitation |
| US4087208A (en) * | 1976-06-08 | 1978-05-02 | Mitsubishi Jukogyo Kabushiki Kaisha | Method for compressing mixed gas consisting of combustible gas and air |
| US4151725A (en) * | 1977-05-09 | 1979-05-01 | Borg-Warner Corporation | Control system for regulating large capacity rotating machinery |
| US4336001A (en) * | 1978-09-19 | 1982-06-22 | Frick Company | Solid state compressor control system |
| JPS55123394A (en) * | 1979-03-12 | 1980-09-22 | Hitachi Ltd | Capacity control of centrifugal compressor |
| US4351160A (en) * | 1980-06-16 | 1982-09-28 | Borg-Warner Corporation | Capacity control systems for screw compressor based water chillers |
| DE3213155A1 (en) * | 1982-04-08 | 1983-10-13 | VIA Gesellschaft für Verfahrenstechnik mbH, 4000 Düsseldorf | Method for the monitoring of a compressed air generating system and device for carrying out the method |
| JPS5949388A (en) * | 1982-09-13 | 1984-03-21 | Toshiba Corp | Operating method and device for water sealed vacuum pump |
-
1984
- 1984-05-30 DE DE19843420144 patent/DE3420144A1/en not_active Ceased
-
1985
- 1985-05-23 CA CA000482134A patent/CA1244914A/en not_active Expired
- 1985-05-24 EP EP85106437A patent/EP0169336A1/en not_active Withdrawn
- 1985-05-28 NO NO852106A patent/NO852106L/en unknown
- 1985-05-29 DK DK239085A patent/DK239085A/en not_active Application Discontinuation
- 1985-05-30 JP JP60115514A patent/JPS611886A/en active Granted
- 1985-05-30 US US06/739,553 patent/US4655688A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| DE3420144A1 (en) | 1985-12-05 |
| JPH0158357B2 (en) | 1989-12-11 |
| EP0169336A1 (en) | 1986-01-29 |
| NO852106L (en) | 1985-12-02 |
| US4655688A (en) | 1987-04-07 |
| JPS611886A (en) | 1986-01-07 |
| DK239085A (en) | 1985-12-01 |
| DK239085D0 (en) | 1985-05-29 |
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