US2873910A - Sludge-discharging centrifugal separators - Google Patents

Description

Feb. 17, 1959 P. STEINACKER 2,873,910

7 VSLUDGE-DISCHARGING CENTRIFUGAL SEPARATORS Filed March 11, 1955 Z SheetS-Sheet 1 PETER STE/NAG/(ER I INVENTOR ATTORNEYS Feb. 17, 1959 P. STEINACKER 2,873,910

SLUDGE-DISCHARGING CENTRIFUGAL SEPARATORS Filed March 11, 1955 2 Sheets-Sheet 2 PE 7-5/2 STE/NACKER Q r VINVENTOR ATTORNEYS United States Patent .SLUDGE-DISCHARGING CENTRIFUGAL SEPARATORS Peter Steinacker, Oelde, Germany, assignor to Weslfalia Separator A. G.,' Oelde (Westphalia), Germany, 'a German corporation Application March 11, 1955, Serial No.49s,s99 Claims priority, application Germany March 13, 1954 8 Claims. (Cl. 233-20) closed position;

period of operation and the accumulation of the sludge,

the sleeve valve is moved to a' position in which the sludge-discharge ports are open and thesludge is dis charged from the bowl therethrough.

The movement of the sleeve valve may be effected by the pressure in the centrifugal bowl and/ or by providing the same with an inwardly projecting radial flange and introducing liquid below and/or above the flange to move the sleeve valve in either direction.

Thus, for example, the centrifugal bowl may comprise an outer casing and the inwardly projecting radial flange connected to the sleeve valve may form the top or bottom surface of the bowl interior.- The radial flange may be spaced from the adjacent casing wall of the bowl to form a closure chamber therebetween. Liquid maybe introduced to this closure chamber, and, due to the centrifugal force, will hydraulically force the radial flange and sleeve-valve to the closed position. If the liquid is allowed to escape from this closure chamber,

the pressure in the bowl will force the radial flange and J A a position opening and a position sealing the valve port.

sleeve valve in the oppositejdirection opening the discharge ports and allowing escape of the accumulated sludge; When the centrifugal separators operate at a high speed of rotation, it is of extreme importance that the discharge ports are opened suddenly, so that the sludge which has collected within the bowl can be dependably carried out of the bowl by the sudden differ ential pressure produced across the discharge ports. If the ports are Opened too slowly, a good deal of wear of the packings may occur, and the danger exists that the ports themselves will become partially cloggedf Such a clogging often results in causing imbalance of the bowl, endangering further centrifugal operation. z In all prior proposals, utilizing a valve to empty the closure chamber, a special fluid feed in addition to the feed for the closure liquid was required for the actuation which was necessary. Further, in the prior suggestions,

theclosure of the valve was aided by the pressure of the liquid in the closure chamber, so that the valve had to be brought to its open position against this pressure.

This arrangement would not allow as rapid an action of thevalveaswas desirable, since the speed of actuation 2,873,910 Patented Feb. 17, 1959 ice would be dependent on the excess pressure of the control liquid for actuating the valve over the pressure of the closure liquid in the closure chamber. v

One object of this invention is an improved sludge-discharging centrifugal separator having a quick-acting discharge valve for discharging liquid from the closure chamber, which is actuated by the same liquid feed "as used to fill the closure chamber with liquid, and which is not actuated to its open position against the liquid pressure in the'closure chamber. These, and still further objects will become apparent from the following description, read in. conjunction with the drawings, in which: j

Fig. 1 shows a vertical sectionfof the left-hand side of an embodiment ofa centrifugal separator in accord ance with the invention, with the sleeve valve in the Fig. 2 shows a vertical section of the right-hand side of the centrifuge shown in-Fig. l with the sleeve valve in theopen position; v

Fig. '3 is a vertical section showing in further detail the liquid-release valve from the closure chamberof the embodiment showns in Figs. 1 and 2; and

. Fig. 4 is a vertical section showing in detail a different embodiment of a valve construction for emptying the closure chamber in accordance with the invention.

The invention basically relates to improvements in a sludge-discharging centrifugal separator having a centrifugal bowl with peripheral sludge-outlet openings and an axially movable sleeve valve movable between a position opening and a position closing the sludge-discharge openings. The centrifuge'also has an inwardly extending radial flange, preferably defining the upper or lower surface of the bowl interior. The radial flange is connected to the sleeve valve and defines a closure chamber on the sidethereof outward of the interior of the bowl for passage of liquid therein under centrifugal pressure for the closing actuation of the sleeve valve. The opening actuation of the the sleeve .valve is effected by allowing the liquid to flow. out of the closure chambern whereby the centrifugal pressure in the bowl will force the flange and sleeve valve to the open position.

In accordance with the in'vention, the centrifuge is provided with a valve port defining a path of liquid flow out from the peripheral portion "of the closure chamber. A valve body is movably positioned between The movement of the valve body from said open to said sealing position is against liquid under centrifugal pressure'in said closure chamber. A valve chamber is provided in pressure communication with the side of the valve body substantially opposite the valve port. Pressure communication is preferably indirect through a deformable diaphragm which is in contact with the valve body but which seals the same from direct contact with the liquid in the valve chamber.

.A throttle discharge opening is defined through the peripheral portion of the valve chamber. A common liquid inlet is provided for passing liquid into the valve chamber and into the closure chamber, preferably so that the liquid first flows into the. valve chamber and then overflows into the closure chamber. The liquid inlet means and the throttle discharge must be so constructed that liquid may be passed in through the liquid inlet faster than the same will be forced out by centrifugal force through the throttle discharge. With this construction, upon the shutting off'of the closure liquid feed passing through the liquid inlet means, the liquid in the valve chamber is forced by centrifugal force through the throttle discharge, so that the valve experiences. a sudden releaseof pressure on one side, while the pressure of the liquid in the closure chamber on the'other' side acts in the opening direction, rapidly moving the valve body to open the'valve'port. The valve port and the conduits leading therefrom to the exterior of the centrifuge are, so dimensioned that the liquid in the closure, chamber is instantly thrown out when the valve is opened. Due to the sudden emptying of the closure chamber, the sleeve valve and flange are quickly moved, causing sudden opening of the sludge-discharge openings, so that the pressure in the centrifugal bowl will act instantaneously to its fullest extent on the layer of sludge, so that clogging of the sludge in the outlet openings is practically impossible.

Referring to the embodiment shown in Figsl, 2, and 3, the sludge centrifuge consists of a centrifugal bowl which has been prepared in two sections, and having the lower bowl portion 1 and upper bowl portion 2, joined or screwed together by means of a thread'3.

The bowl is centrifugally rotated by means of the shaft 22 driven by any suitable drive means (not shown),

. The centrifugal bowl has the peripheral sludge and dis: charge ports or openings 7 and the sleeve valved, which is axially displaceable between the position as shown in Fig. l in sealing contact against the packing gasket 5 closing the sludge-discharge ports 7 and an opening position, as shown in Fig. 2, opening the sludge-discharge ports 7 for communication with the interior of the bowl.

An inwardly extending radial flange 23. is connected to and. movable with the sleeve valve 4. The radial flange 23 forms the upper surface of the bowl interior and is spaced from the adjacent casing wall of the centrifugal bowl, so as to define a closure chamber 14. When liquid is passed into the closure chamber 14 while thebowl is rotating, the centrifugal force will force the flange 23 and sleeve valve 4 to the closed position, as shown in Fig. l.

A valve port 13 is provided through the peripheral portion of the closure chamber 14.

' A valve body which, as shown in Figs. 1, 2, and 3, has a cylindrical shape, is axially movable between a position as shown in Fig. 1, sealing the valve port, and a position as shown in Fig. 2, opening the valve port 13. The movement of the cylindrical valve body 12 to. the sealing position is against any liquid pressure in the closure "chamber 14.

When the valve body 12 is in the open position, the valve port 13 is in liquid flow communication with an annular space 17 surrounding thevalve body and the con: duits 18 and 19 which lead to the exterior of the centrifugal bowl, allowing the emptying of the closure chamber 14 of any liquid, due to centrifugal force.

A channel 9, and the valve chamber 11 are in pressure communication with the side of the valve 12 opposite the valve port. As shown, the pressure communication is through an elastic deformable diaphragm 20 in contact with the valve body 12. The diaphragm 20 allows liquid pressure in the valve chamber 11 to be fully utilized to move the valve body 12 to seal the valveport 13. The diaphragm 20 also preferably seals the valve body 12 and the portions of the chamber in which the same moves from direct contact with liquid in the valve chamber 11, and this prevents any leakage through the valve guide. This is very advantageous, since, even when pure water is used as the closure liquid, extremely fine'impurities readily settle out under centrifugal force in the valve guide. The diaphragm 20 may also act as a seal to prevent any communication between the closure chamber 14 and valve chamber 11. The guide for the valve will thus at all times remain clean, so that the valve cannot seize.

A throttle discharge opening through the peripheral portion of the valve chamber provides a passage'for'liquid out of the valve chamber 11 and the channels 10 and 9.

A liquid inlet 8, which is controlled by a valve, is positioned for passing liquid through the channels 9 and 10 into the valve chamber 11- and overflowing the same into h cl su cham r h hanne s Jam -1 nd e 4 The valve chamber 11 reaches nearer to the bowl periphery than the closure chamber 14 In place of the cylindrically shaped valve body 12 as shown in Figs. 1, 2, and 3, a ball-shaped valve body 21 may be utilized, as shown in Fig. 4.

In operation, the centrifugeds rotated by driving the shaft 22 by any suitable drive means, such as an electric motor. A closure liquid, such as water, is passed in through the inlet 8. Due to the centrifugal force, the liquid first passes through the channels 9 and. into the valve chamber 11, completely filling the same. The hydraulic pressure caused by the centrifugal force presses on the diaphragm 20, forcing the valve body 12 toward the valve port 13, sealing the same. As the valve chamber 11 fills, the 'closure'liquid, such as the water, continuously flows out of the same, through the throttle opening 15. The inlet 8 and the throttle opening 15 should be so dimensioned that the liquid may be passed in through the inlet 8 at a faster rate than the same is centrifuged out through the throttle opening 15. The liquid will thus fill the entire chamber and overflow into the closure chamber 14. In the closure chamber 14 the liquid will build up hydraulic pressure, due to the centrifugal aetion. Since, however, the hydraulic force of the liquid in the valve chamber 11 is greater than in the closure chamber 14, because the diaphragm 20, on which the liquid in the valve chamber 11 acts, has a greater surface area than the surface area of the valve body 12 acted upon by the liquid in the closure chamber .4, the valve body 12 will remain in the closed position. The hydraulic pressure in the chamber 14 will act on the sleeve valve 4 and flange 23, forcing the sleeve valve to the closed position, as shown in Fig, 1. If the closure liquid completely fills the conduits 9 and 1 0, the same then overflows via port 25.

The liquid material to be de-sludged or clarified, is passed in the centrifuge in the conventional manner through the inlet 24. The same is clarified by the cent rifugal action in the bowl and the sludge builds up at the V- or wedge-shaped peripheral portion of the bowl.

After the sludge has been allowed to accumulate for a period of time, the valve in the inlet 8 is closed.

The liquid in the valve chamber 11 will be forced out through throttle opening 15, emptying the valve chamber 11 and relieving the hydraulic pressure on the diaphragm 20.

The hydraulic pressure in the closure chamber 14 will then act on the valve body 12, quickly forcing the same into the open position. Due to its elasticity, the diaphragm 20 does not hinder the movement of the valve body 12. The closure liquid in the closure chamber 14 is then rapidly centrifuged out through the annular opening 17 and the conduits 18 and 19 to the exterior of the centrifuge. With this rapid removal of the liquid in the othe n rd toward t e ax of ro ion of th s nt ifqs r closure chamber, the centrifugal pressure of the liquid in the centrifugal bowl acts on the flange 23 and sleeve valve 4, quickly forcing the same upwardly to the open position, as shown in Fig. 2, The centrifugal pressure in the bowl then instantaneously acts upon the sludge, which has accumulated, quickly forcing the same out through the sludge-discharge ports 7.

After the sludge has been removed, the valve in the inlet 8 is opened, the liquid flows into the valve chamber 11, exerting force on the diaphragm 20, closing the. valve port 13 by moving the valve body 12 The liquid then again overflows from the portion 9 into the closure chamba .4 us twins t e ra a fl ng Z3 a d t sle e valve 4 to the closed position.

h valve n smsp is cordanc i t ntion is, of course, also applicable for sludge centrifuges in which the sleeve valve is arranged in the lower part of the centrifuge bowl.

1 laim:

In a, s ntr i ysal se ara e having ssptr u bo i h p ri h l e des-spla swin s an an ax l movable sleeve valve, movable between a position opening and a position closing said sludge-discharge openings, an inwardly extending radial flange connected to said sleeve valve, defining a closure chamber on the side thereof outward the interior of the bowl for the passage of liquid therein under centrifugal pressure for the closing actuation of said sleeve valve, the improvement which comprises a valve port defining a path of liquid flow out from the peripheral portion of said closure chamber, a valve body movably positioned between a position opening and a position sealing said valve port, said valve body being positioned with respect to said valve port and closure chamber so that said movement from said open to said scaling position is against any liquid pressure in said closure chamber, a valve chamber in pressure communication with the side of said valve body substantially opposite said valve port, a throttle discharge opening defined through the peripheral portion of said valve chamher, and common liquid inlet means for passing liquid into said valve chamber and into said closure chamber.

2. Improvement according to claim 1, in which said valve chamber, closure chamber, and inlet means are positioned so that liquid from said inlet means will flow into said valve chamber and overflow therefrom into said 4. Improvement according to claim 3, in which said feeding channel for said valve chamber and the closure chamber extend substantially parallel to each other.

5. Improvement according to claim 1, including a deformable diaphragm positioned in contact with said valve body and sealing said valve body from direct con tact with liquid in said valve chamber.

6. Improvement according to claim 5, in which said valve body is a cylindrically shaped, axially movable valve body.

7. Improvement according to claim 5, in which said valve body is a ball-shaped valve body.

8. Improvement according to claim 1, including a deformable diaphragm positioned in contact with said valve body and sealing said valve body from direct contact with liquid in said closure chamber and including an annular channel surrounding said valve body in flow communication with said valve port when said valve body is in the position opening said valve port and means defining a path of liquid flow from said annular channel to the exterior of the centrifugal bowl.

References Cited in the file of this patent UNITED STATES PATENTS 2,578,484 Nyrop Dec. 11, 1951 FOREIGN PATENTS 400,809 Great Britain Nov. 2, 19s:

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