WO2005115873A1

WO2005115873A1 - Blow molded drum with down tube

Info

Publication number: WO2005115873A1
Application number: PCT/US2005/013138
Authority: WO
Inventors: John M. Hennen; Ray Wolf; Thomas J. Whalen
Original assignee: Entegris, Inc.
Priority date: 2004-04-18
Filing date: 2005-04-18
Publication date: 2005-12-08

Abstract

A down tube assembly for dispensing liquid from an interior of a drum, the assembly including a down tube configured to operably couple an access opening included on an upper wall of the drum, the down tube extending into the interior of the drum. The assembly further including an extension tube configured to operably couple the down tube, the extension tube extendable along a longitudinal axis of the extension tube between extended and compressed states, the extension tube biased to the extended state such that a lower end of the extension tube extends toward a bottom wall of the drum when the down tube is placed into the drum.

Description

BLOW MOLDED DRUM WITH DOWN TUBE

This application claims priority to U.S. Provisional Application 60/563,540, filed April 18, 2004, entitled "BLOW MOLDED DRUM WITH DOWN TUBE," which is incorporated herein by reference. Field of the Invention

This invention relates generally to fluid dispensing systems. More particularly, the invention relates to drum inserts and down tubes for use with fluid dispensing systems.

Background of the Invention

In industries such as semiconductor processing, pharmaceutical, and chemical manufacturing, high purity, highly corrosive, and highly caustic liquids are often utilized. Due to safety and quality considerations, these liquids must be contained in containers and dispensing systems having high reliability and integrity. The connections, tubing, and fittings for handling these fluids must be formed from highly inert materials. Fluoropolymers have been found to be suitable for use in these environments. The tubing is commonly formed of PFA, while the fittings, valve components, and dispense heads may be formed of components such as PFA, PTFE, and other various other fluoropolymers.

Containers for handling these liquids are typically plastic drams formed of high purity polyethylene, such as shown in U.S. Patent No. 6,045,000, which is owned by Applicant and incorporated herein by reference. These containers typically have at least one threaded nipple or bung defining an access opening or bunghole for dispensing chemicals into and out of the drum. A cap or closure is placed on the threaded nipple for shipment and storage of the dram. At least one chime or carrying and transportation ring can also be included on the drum shell for grabbing by conventional mechanized drum handling equipment.

A drum insert having a down tube and a dispense head coupled to the drum insert can be utilized to remove the chemicals from an interior of the container. Examples of dispense heads suitable for use with these drums are depicted and described in U.S. Patent Nos. 4,699,298, 5,108,015, 5,957,328, and 5,526,956, with each of the referenced applications being incorporated herein by reference in their entirety.

In some circumstances, the aforementioned drums are subject to fluctuations along their height, or longitudinal axis, based on variables such as whether the dram is filled with fluid. When the longitudinal axis is lengthened, the down tube can become spaced away from the bottom wall of the blow-molded drum leaving a portion of chemicals in the drum indispensable. Conversely, when the longitudinal axis is shortened, the down tube can be forced against the bottom wall, effectively obstructing the conduit within the down tube. Because the general problems discussed above have not been addressed, there is a current need for a down tube assembly addressing the problems and deficiencies inherent with conventional designs.

Summary of the Invention

The down tube assembly of the various embodiments of the present invention substantially solves the problems of conventional dispense systems by providing a down tube having an extension tube that is capable of longitudinal movement to extend and fill a gap created by movement of an end of the down tube away from the bottom wall of the drum. The down tube assembly is also capable of longitudinal movement to retract or collapse when the end of the down tube is forced toward the bottom wall of the dram. The down tube assembly is also capable of abutting the bottom wall of the drum while maintaining a constant volume of fluid flow out of the down tube.

A feature and advantage of a preferred embodiment of the invention is that the extension tube may be configured as a bellows and is self-extendable and able to fill a gap that can form between the down tube and the bottom wall of the container. Such a configuration can provide a downward bias to keep the bottom edge of the extension tube engaged with the inside bottom surface of the dram assuring maximum withdrawal of the fluid therein. Another feature and advantage of embodiments of the invention is that the undulating edge of the extension tube ensures a constant volume of liquid flows into the extension tube.

Another feature and advantage of embodiments of the invention is that the coupler has a shroud portion extending about the extension tube for limiting lateral movement and ensuring proper positioning of the undulating edge adjacent to the bottom wall of the container.

Another feature and advantage of embodiments of the invention is that the undulating edge of the shroud ensures a constant volume of liquid flows into the extension tube.

Brief Description of the Drawings

Fig. 1 is a side elevational view depicting a down tube extension assembly positioned in the interior of a blow-molded dram according to an embodiment of the present invention; Fig. 2 is a side elevational view depicting a down tube extension assembly coupled to a down tube according to an embodiment of the present invention;

Fig. 3 is a cross-sectional view depicting a down tube extension assembly coupled to a down tube according to an embodiment of a down tube extension assembly

Fig. 4 is a side elevational view depicting a down tube extension assembly coupled to a down tube according to an embodiment of the present invention;

Fig. 5 is a side elevational view depicting an extension tube according to an embodiment of the present invention;

Fig. 6 is a cross-sectional view depicting an extension tube according to an embodiment of the present invention; Fig. 7 is a perspective view of a coupler for the down tube extension assembly according to an embodiment of the present invention; Fig. 8 is a side elevational view of a coupler for the down tube extension assembly according to an embodiment of the present invention;

Fig. 9 is a cross-sectional view of a coupler for the down tube extension assembly according to an embodiment of the present invention; Fig. 10 is a top plan view of a coupler for the down tube extension assembly according to an embodiment of the present invention; and

Fig. 11 is a side elevational view depicting a down tube extension assembly coupled to a down tube according to an embodiment of the present invention.

Detailed Description of the Drawings Referring to Fig. 1, a down tube extension assembly according to the invention is shown and is generally indicated by the numeral 18. The principle components of the present invention are a drum 10, a drum insert 12 having an upper portion 14 and a down tube 16, and a down tube extension assembly 18.

As can be seen in Fig. 1, a drum 10 includes a side wall portion or peripheral wall 22, a first end or top wall 24, and a second end or bottom wall 26 generally opposed the top wall 24. The dram 10 also comprises an interior 28 for holding chemicals, which are often high purity, highly corrosive, and/or highly caustic liquids. The drum 10 can include at least one nipple or bung 30 defining an access opening or bunghole 32 used to dispense fluids out of the interior 28 of the dram 10 or recirculate fluids back into the interior 28 of the drum 10. In one embodiment, the bung 22 comprises internal threads that are configured to match threading on conventional drum inserts 12 and/or bung closures 13. The dram 10 also can include an upper chime 31 proximate the first end 24 of the dram 10 and a lower chime 33 proximate the second end 26 of the drum 10 to protect the bungs 22 and/or to provide handling equipment contact surfaces on which to grab the drum 10. The drum 10 can be constructed of single or multiple layers, such as polymers formed in a blow molding process. While the drum 10 according to one embodiment is constructed of a flouropolymer, such as polyethylene, other polymer materials can be used without departing from the scope of the present invention. Examples of drams 10 that can be employed with the various embodiments of the present invention are disclosed in U.S. Patent No. 6,045,000 and U.S. Patent Application Publication No. 2002/0050494, both of which are incorporated herein by reference.

As can be seen in Fig. 1, the drum 10 can also include a drum insert 12 having an upper portion 14 and a down tube 16. The down tube 16 comprises a first end 34 that can be operably coupled to or seated in the upper portion 14 of the drum insert 12 proximate the bunghole 32 and a second end 36 generally opposed the first end 34 and positioned within the interior of the drum 10. The down tube 16 also includes a down tube conduit 35 permitting the flow of fluids through the down tube 16. Fluid dispensing systems can also include a dispense head 11 operably coupled to the upper portion 14 of the dram insert 12 for dispensing fluid from, and recirculating fluid back into, the drum 10. Examples of dispense heads suitable for use with drums 10 of the various embodiments of the present invention are depicted and described in U.S. Patent Nos. 4,699,298, 5,108,015, 5,957,328, and 5,526,956, each of which are incorporated herein by reference.

Referring to Figs. 2-4, the extension tube assembly 18 according to an embodiment of the present invention includes an extension tube 19 and a coupler 20 for operably coupling the extension tube 19 to the second end 36 of a conventional down tube 16 as described above. In one embodiment, the extension tube 19 is constructed of PTFE and the coupler 20 is constructed of HDPE, although other materials can be used without departing from the scope of the present invention. As can be seen in Figs. 3, 5 and 6, the extension tube 19 includes a first end 38, a second end 40, and a side wall 42 defining a extension tube conduit 37, which is in fluid communication with the down tube conduit 35. A socket 44 for receiving an extension tube connector portion 62 of the coupler 20 is formed on the first end 38 of the extension tube 19. In one embodiment, at least a portion of the side wall 30 preferably has a billows configuration and undulates such that the side wall 42 has a plurality of alternating generally curvilinear peaks 46 and valleys 48, such that the side wall can be compressed and extended by compressing and extending the sidewall 42 portion including the peaks 46 and valleys 48. When the natural length of the downtube with the beillows portion49 is greater than the distance from the access port to the bottom inside surface of the dram, the bellows absorbs the distance differential and provides a bias to the bottom tip of the downtube to keep the downtube engaged with the inside surface of the bottom of the dram. The extension tube 19 also includes a longitudinal axis 39, as can be seen in Figs. 5 and 11.

The side wall 42 portion of the extension tube 19 can be thinner in the undulating portion of the side wall 42, which allows the undulating side wall 42 to move longitudinally between the compressed and extended states. When the extension tube 19 is inserted into the drum 10, the free second end 40 of the extension tube 19 can be positioned such that it abuts the bottom wall 26 of the drum 10. When the extension tube 19 is placed in such a position, the extension tube 19 can be compressed from its natural, extended state towards a compressed state, and vice versa, depending upon the relative depth of the drum 10.

Referring to Fig. 5, in an embodiment, an edge 50 of the free second end 40 can undulate with a plurality of alternating generally curvilinear peaks 52 and valleys 54. When the undulating edge 50 of the free second end 40 abuts the bottom wall 26 of the dram 10, fluid in the dram 10 can flow through the valleys portions 54 and into the extension tube 19. In one embodiment, to ensure that a constant volume of fluid flows through the extension tube 19 at all times, the combined length of the undulating edge 50 between all of the alternating peaks 52 on the free second end 40 is generally equal to an inner diameter of the extension tube 19. While the alternating peaks 52 and valleys 54 are depicted and described as being generally curvilinear, the peaks 52 and valleys 54 can be linear without departing from the scope of the present invention. In another embodiment, the second end 40 comprises a plurality of apertures or slots, allowing fluid to flow through the apertures or slots, particularly when the edge 50 of the second end 40 completely abuts the bottom surface 26 of the drum 10.

As can be seen in Figs. 7 and 8, in an embodiment, the coupler 20 of the down tube extension assembly 18 can have a shroud or skirt 58 extending from an angular shoulder 59. The coupler 40 can include an upper neck or down tube connector portion 66 extending away from the shoulder 59 for coupling with the free second end 36 of the down tube 16. The coupler 20 also includes a lower neck or extension tube connector portion 62 extending away from the shoulder 59 and extending generally through an interior of the shroud 58. The extension tube connector portion 62 can include a lip or flange 64 to allow for better slidable connection between the extension tube connector portion 62 and the extension tube 19. As can be seen in Fig. 3, the socket 44 of the extension tube 19 is coupled to the lower neck 62 such that a portion of the extension tube 19 is positioned in the interior of the shroud 58. A channel 57 extends through the upper 66 and lower 62 neck portions permitting fluid to flow through from the interior 28 of the drum 10 through the extension tube 19 and coupler 20 and into the second end 36 down tube 16. Referring to Fig. 3, which is a cross section depicting the down tube extension assembly 18, including the socket 44 of the extension tube 19 slidably coupled to the extension tube connector portion 62 of the coupler 20. Fig. 3 also depicts the coupler 20 slidably connected to the second end 36 of the down tube 16 by a down tube connector portion 66 of the coupler 20. In other embodiments of the present invention, the socket 28 of the extension tube 19 can be coupled to the extension tube connector portion 62 of the coupler 20 and the coupler 20 connected to the second end 36 of the down tube 16 by a down tube connector portion 66 of the coupler 20 by other mechanisms, such as by threading on the various components, without departing from the scope of the present invention. As illustrated in Fig. 6, the shroud 58 can be configured so as to limit a lateral movement of the extension tube 19, thus ensuring proper positioning of the extension tube 19 so .that it is adjacent to the bottom wall 26 of the drum 10. The shroud 58 also includes a skirt or shroud free end 65 that is can abut the bottom wall 26 of the drum 10 for preventing a complete collapsing of the extension tube 19 that could effectively block the flow of fluid through the extension tube conduit 37.

In one embodiment, as can be seen in Figs. 9 and 10, to prevent an obstruction of fluid flow, the shroud 58 preferably includes at least one coupler conduit 61 and channel 57 extending therethrough for permitting fluid to enter the interior of the shroud 58 so that it maybe drawn into the extension tube 19. As particularly illustrated in Fig. 8, the shroud 58 may also comprise elongate slots 60 extending from a portion of the shoulder 59 towards a main inlet 63 of the shroud 59. Other inlet shapes and configurations are also possible, for instance, a plurality of inlets may extend through the shroud 58.

In other embodiment, as can be seen by way of broken lines in Fig. 2, the free end

65 of the shroud 58 may also have an undulating edge 67 with alternating peaks 68 and valleys 70. When the shroud 58 abuts the bottom wall 26 of the drum 10 and the fluid level in the drum 10 is lower than the main inlet 63 of the shroud 58, fluid may still enter the main conduit 61 of the shroud 58 through the valleys 70 created by the undulating edge 67. The valleys 54 and 70 of the extension tube 19 and the shroud 58, respectively, can both be included to prevent obstruction of fluid flow into the extension tube 19. In another embodiment, the free end 65 of the shroud 58 comprises a plurality of apertures or slots, allowing fluid to flow through the apertures or slots when the free end 65 of the shroud 58 completely abuts the bottom surface 26 of the drum 10.

In operation, the extension tube 19 and the coupler 20 are coupled together by inserting the lower neck 62 of the coupler 20 into the socket 44 of the extension tube 19. The coupler 20 is then coupled to the free end 36 of the down tube 16. Once the down tube extension assembly 18 is coupled to the down tube 16, the drum insert 12 with down tube 16 can then be inserted into the drum 10. When the upper portion 14 of the drum insert 12, and thus the first end 34 of the down tube 16, is seated in the bung 30, the undulating edge 50 of the extension tube 19 operably abuts the bottom wall 26 of the drum 10 such that the extension tube 19 is moved from its natural, extended state toward its compressed state.

If the drum 10 expands causing an increase in a height of the drum 10, the extension tube.19 will move from the compressed state towards its natural, extended state, thereby ensuring that the undulating edge 50 of the extension tube 19 stays in contact with the bottom wall 26 of the drum 10. If the dram 10 shrinks such that it causes a decrease in the length of the dram 10, the extension tube 19 can become generally more compressed. The undulating edge 50 of the extension tube 19 ensures that the entire edge 50 of the extension tube 19 does not contact the bottom wall of the drum 10, effectively blocking flow of the fluid out of the interior 28 of the drum 10. If the dram 10 shrinks, such that the free edge 65 of the shroud 58 abuts the bottom wall 26 of the drum 10, fluid is able to flow through the inlet 63 of the shroud 58 and into the extension tube 19. Once the fluid level falls below the inlet 63 it may flow through the valleys 70 of the undulating edge 65 of the shroud 58 and further through the slots 60.

As can be seen in Fig. 11, in another embodiment of the present invention, the extension tube 19 is not compressed in a linear manner, but rather flexed or extended along the longitudinal axis 39, wherein free end 40 of the extension tube 19 is at an angle with respect to the down tube 16. In this configuration, a substantial portion of the liquid contained within the drum can be nonetheless be dispensed from the drum 10, as a portion of the free end 40 of the extension tube 19 abuts the bottom wall 26. This configuration can result intentionally or when compressive forces exerted on the extension tube 19 cause the free end 40 to slide out from underneath the down tube 16.

In another embodiment of the present invention, the extension tube 19 can be operably coupled directly to the down tube 16 without the use of a coupler 20.

Although the present invention has been described with reference to particular embodiments, one skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and the scope of the invention. Therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive.

Claims

1. A down tube assembly for dispensing liquid from a drum, the down tube assembly comprising: a down tube configured to operably couple an access opening included on an upper wall of the drum, at least a portion of the down tube extending into an interior of the drum; an extension tube configured to operably couple the down tube, the extension tube extendable along a longitudinal axis of the extension tube between an extended state and a compressed state, the extension tube biased to the extended state such that a lower end of the extension tube extends toward a bottom wall of the drum when the down tube is placed into the interior of the drum.

2. The down tube assembly of claim 1, wherein when the extension tube extends toward the bottom wall, such that at least a portion of a lower end of the extension tube operably abuts the bottom wall.

3. The down tube assembly of claim 2, wherein the extension tube has a bellows portion .

4. The down tube assembly of claim 3, wherein when the drum height increases, the extension tube extends to compensate for an increased dram height, and when the dram height decreases, the extension tube compresses to compensate for a decreased drum height.

5. The down tube assembly of claim 1, wherein a lower end of the extension tube comprises tube valleys and tube peaks, such that when the when the extension tube extends toward the bottom wall, at least a portion of the tube peaks operably abuts the bottom wall and a flow path is defined between the tube valleys and the bottom wall.

6. The down tube assembly of claim 1, further comprising a coupler for operably coupling the extension tube and down tube.

7. The down tube assembly of claim 6, wherein the coupler comprises a shroud having shroud valleys and shroud peaks, such that when down tube extends into the interior of the drum, the shroud peaks are configured to operably abut the bottom wall and the shroud valleys are configured to be spaced apart from the bottom wall.

8. The down tube assembly of claim 6, wherein the coupler comprises a shroud having a slot configured thereon to allow the liquid to flow through the coupler.

9. The down tube assembly of claim 6, wherein the coupler is constructed of high-density polyethylene.

10. The down tube assembly of claim 1, wherein the extension tube is constructed of Polytetrafluoroethylene.

11. A method of dispensing liquids dispensing liquid from an interior of a drum comprising: providing a down tube configured to operably couple an access opening included on an upper wall of the drum; coupling an extension tube and down tube, the extension tube extendable between an extended state and a compressed state along an axis of the extension tube; inserting the down tube into the access opening, such that the down tube extends into the interior of the dram and a lower end of the extension tube operably abuts a bottom wall of the dram; and operably coupling the down tube and access opening.

12. The method of claim 11, further comprising drawing a liquid out of the interior of the dram through the extension tube and down tube.

13. The method of claim 11 , further comprising: providing tube valleys and tube peaks on the lower end of the extension tube, such that when down tube extends into the interior of the dram, the tube peaks are configured to operably abut the bottom wall and the tube valleys are configured to be spaced apart from the bottom wall; and drawing a liquid out of the interior of the drum through the extension tube and down tube, such that when the peaks abut the bottom wall the liquid is drawn through a flow path defined between the tube valleys and the bottom wall.

14. The method of claim 11 , further comprising: providing a coupler to operably couple the extension tube and down tube, the coupler including a shroud having shroud valleys and shroud peaks on a bottom edge of the shroud, such that when down tube extends into the interior of the drum, the shroud peaks are configured to operably abut the bottom wall and the shroud valleys are configured to be spaced apart from the bottom wall; and drawing liquid out of the interior of the drum through the shroud, extension tube, and down tube, such that when the shroud peaks abut the bottom wall the liquid is drawn through a flow path defined between the shroud valleys and the bottom wall.

15. A down tube assembly for dispensing liquid from a drum, the down tube assembly comprising: a down tube configured to operably couple an access opening included on an upper wall of the drum, at least a portion of the down tube extending into an interior of the drum; and means for extending the down tube configured to operably couple the down tube, the means for extending extendable along a longitudinal axis of the means for extending between an extended state and a compressed state, the means for extending biased to the extended state, such that a lower end of the means for extending operably abuts a bottom wall of the drum when the down tube extends into the interior of the drum.

16. The down tube assembly of claim 15, wherein the means for extending comprises a bellows portion.

17. The down tube assembly of claim 16, wherein when the drum height increases, the means for extending extends to compensate for an increased drum height, and when the drum height decreases, the means for extending compresses to compensate for a decreased dram height.

18. The down tube assembly of claim 15, further comprising means for allowing liquid to flow into the lower end of the means for extending when the lower end of the means for extending operably abuts the bottom wall of the drum.

19. The down tube assembly of claim 15, further comprising means for operably coupling the means for extending and down tube.

20. The down tube assembly of claim 19, wherein the means for coupling comprises a shroud having means for allowing liquid to flow into the coupler when a bottom edge of the shroud operably abuts the bottom wall of the drum.

21. The down tube assembly of claim 19, wherein the means for coupling comprises a shroud having shroud valleys and shroud peaks, such that when down tube extends into the interior of the drum, the shroud peaks are configured to operably abut the bottom wall and the shroud valleys are configured to be spaced apart from the bottom wall.