GB2507029A

GB2507029A - Pump with second inlet in outlet passage for mixing fluids

Info

Publication number: GB2507029A
Application number: GB1212339.4A
Authority: GB
Inventors: Jonathan Edward Ford; Richard Paul Hayes-Pankhurst
Original assignee: Quantex Patents Ltd
Current assignee: Quantex Patents Ltd
Priority date: 2012-07-11
Filing date: 2012-07-11
Publication date: 2014-04-23
Anticipated expiration: 2032-07-11
Also published as: GB2507029B; GB201212339D0

Abstract

A pump comprising a housing 12 between inlet and outlet passages 14, 11, and a rotor 17 within the housing. The rotor includes a surface which engages with an interior surface of the housing to form a seal, and at least one shaped surface which is radially inward of the housing engaging surface so as to form a pump chamber between the rotor and housing. A seal is provided between the outlet and inlet passages, and is urged into engagement with the rotor. The outlet passage includes a second inlet 141 for passing a second fluid to the outlet passage, and a device downstream of the second inlet for mixing the fluid from the rotor with the fluid from the second inlet. The inlet and outlet passages, seal and housing may be formed as a one-piece moulding. An inner tube 144 may be provided coaxially within the outlet passage, with one fluid passing along the inner tube, and the other fluid passing between the inner tube and outlet passage.

Description

PUMP FITTINGS AND METHODS FOR THEIR MANUFACTURE

The invention relates to pump fittings and methods for their manufacture.

S

It is known to dispense liquids from a container using a pump or tap. Where, for example, the liquid is wine, the container may include a manually operated tap for this purpose. Such taps are not capable of dispensing accurate quantities nor is the flow rate consistent although they are cheap and can be disposed of with the container. Alternatively, the container is connected to a dispenser that includes a peristaltic or diaphragm or other rotary pump that draws liquid from the container for delivery. These are capable of delivering more accurate quantities of liquid but are expensive to provide and require frequent cleaning for hygiene purposes and periodic maintenance.

According to a first aspect of the invention, there is provided, a pump fitting for a container of fluid comprising an inlet adaptor for connection to an outlet of a container of fluid and including an inlet passage, an outlet passage for fluid and a pump housing between the inlet passage and the outlet passage, the pump housing containing a rotor rotatably received in an interior surface of the housing, the rotor including a housing-engaging surface co-operating with the interior surface of the housing to form a seal therebetween and also including at least one shaped surface radially inwardly of the housing-engaging surface and forming with the interior surface of the housing a chamber for conveying fluid from the inlet to the outlet on rotation of the rotor, a seal being provided between the outlet passage and the inlet passage, the seal being urged into engagement with the rotor to prevent fluid passing from the outlet passage to the inlet passage as the shaped surface rotates, the inlet passage) the outlet passage, the seal and the housing being formed as a one-piece moulding.

Such a pump fitting is easy and cheap to produce) can deliver accurate quantities of liquid and may be disposed of with the container.

According to a second aspect of the invention, there is provided a liquid delivery system comprising a pump fitting according to the first aspect of the invention and a container of liquid connected to the inlet passage of the pump fitting.

According to a third aspect of the invention, there is provided a method of manufacturing a pump fitting according to the first aspect of the invention and in which the seal is a flexible diaphragm located in a aperture in the housing and comprising the step of forming the inlet passage, the outlet passage, and the housing as a single moulding and then moulding the diaphragm in situ in one-piece with the inlet passage, the outlet passage and the housing.

The following is a more detailed description of some embodiments of the invention, by way of example, reference being made to the accompanying drawings in which:-Figure 1 is a perspective view of a pump fitting for a container of fluid; Figure 2 is a plan view from above of the pump fitting of Figure 1; Figure 3 is a section on the line Ill-Ill of Figure 2 with a rotor of the pump fitting in a first position; Figure 4 is a similar view to Figure 3 but with the rotor in a second position; Figure 5 is a section on the line V-V of Figure 2 with the rotor in the first position of Figure 3; Figure 6 is a similar view to Figure 5 but with the rotor in the second position of Figure 4; Figure 7 is a similar view to Figure 1 but with the pump fitting partly broken away and with the rotor in the first position of Figures 3 and 5; Figure 8 is a similar view of Figure 7 but with the rotor in the second position of Figures 4 and 6; Figure 9 is a similar view to Figure 6 but showing the pump fitting positioned to connect to a container of liquid, Figure 10 is a similar view to Figure 4 but showing the pump fitting positioned to connect to a container of fluid, Figure 11 is a schematic cross-sectional view of part of a mould tool to be used in a moulding machine for moulding the pump fitting of Figures 1 to 10, and showing a one-piece moulding and first, second third and fourth cores moved to form a mould for a diaphragm seal of the fitting, Figure 12 is an underneath plan view of the mould tool of Figure 11, Figure 13 is a perspective view of a pump fitting of the kind shown in Figures 1 to 12 and showing a drive interface, Figure 14 is a perspective view of a pump fitting of the kind shown in Figures 1 to 12 and including an air inlet for foaming concentrate, Figure 15 is a cross-section of the pump fitting of Figure 14, Figure 16 is a perspective view of a pump fitting of the kind shown in figures 1 to 12 and including a water inlet and a post mixing nozzle, Figure 17 is a cross-section of the pump fitting of Figure 16, Figure 18 shows the pump fitting of Figures 15 and 16 with a drive and a container of material to be pumped, and Figure 19 is a modification of the pump fitting of Figures 16 to 18 to include a gas inlet for carbonating concentrate, Referring first to Figures 1 to 6, the pump fitting comprises an inlet passage 10, an outlet passage 11 and a pump housing 12 between the inlet passage 10 and the outlet passage 11. The inlet passage 10, the outlet passage 11 and the pump housing 12 may be formed in one piece by a single moulding process from any suitable material. This will be described in more detail below.

As seen in Figures 1 to 6, the inlet passage 10 is generally cylindrical with an outer surface 13 formed with a plurality of axially spaced circumferentially extending ribs 14. The pump housing 12 is generally cylindrical and of smaller diameter than the diameter of the inlet passage 10. The pump housing 12 is carried at a lower end of the inlet passage 10 with its axis normal to the axis of the inlet passage 10. This is best seen in Figures 3, 4, 5 and 6. The pump housing 12 is provided with an inlet opening 15 (see Figures 5 and 6) that provides fluid communication between the inlet passage 10 and the interior of the pump housing 12. The outlet opening 16 (see figures S and 6) provides a fluid connection between the interior of the pump housing 12 and the outlet passage 11. In addition, as seen in Figures 3 and 4, the housing 12 has a closed end 42 and an open end 43.

The outlet passage 11 is generally cylindrical and has an axis that is parallel to the S axis of the inlet passage 10. As seen in Figures 5 and 6, the axis of the outlet passage 11 is spaced from the axis of the inlet passage 10.

A rotor 17 is rotatably received in an interior surface 18 of the pump housing 12. As seen in Figures 3 and 4, the rotor 17 has first and second generally cylindrical ends 19, 20. These ends 19, 20 are a close fit with the interior surface 18 (see Figures 3 and 4) of the pump housing 12 to support the rotor 17 for rotation and to prevent the leakage of fluid between the rotor 17 and the interior surface 18. An end face 44 at the second end 20 of the rotor 17 bears against the closed end 42 of the housing 12. An end face 45 at the first end 19 of the rotor is exposed for connecting the rotor 17 to a drive, as described below.

The rotor 17 is formed with two shaped surfaces 21, 22. As seen in Figures 5 and 6, the surfaces 21, 22 are shaped so that the rotor is generally elliptical in cross section at the centre of the rotor 17 (see Figures 5 and 6) but substantially circular in cross section adjacent the cylindrical ends 19, 20.

The rotor 17 is formed with first and second housing engaging surfaces 23, 24 (see Figures 5 and 6) that extend between the shaped surfaces 21, 22 and seal against the interior surface 18 of a pump housing 12 to prevent the passage of fluid around the rotor 17.

The first and second shaped surfaces 21, 22 form with the interior surface 18 of the S pump housing 12 respective first and second chambers 25, 26. The function of these chambers 25, 26 will be described below in connection with the operation of the pump fitting.

The pump housing 12 is formed, between the outlet opening 16 and the inlet opening 15, with an aperture closed by a flexible diaphragm seal 28. The aperture 27 is surrounded by a wall 29 extending away from the rotor 17 in a direction normal to the axis of the pump housing 12 and projecting into the inlet passage 10. The wall 29 forms a chamber 30 containing a flexible hollow tube 31. As seen in Figure 3, the tube 31, in its substantially uncompressed state, has a minimum diameter at its first and second ends and a maximum diameter intermediate the ends. The tube 31 is pressed into contact with the diaphragm 28 which in turn is pressed into contact with the rotor 17 by a cap 32.

As seen in Figures 5, 6, 7 and 8, the cap 32 includes an annular outer wall 33 that is a sliding fit within the inlet passage 10. Two diametrically opposed part-cylindrical guide surfaces 34a, 34b project upwardly from the outer wall 33 and are also in sliding engagement with the interior surface of the inlet passage 10. A central rib 35 extends between the guide surfaces 34a, 34b. The lower end of the outer wall 33 is closed by a disc 36. As seen in Figures 5 and 6, this disc 36 bears against the tube 31 to force the tube 31 into contact with a diaphragm seal 28. As seen in fig 10, the free ends of the guide surfaces 34a, 34b include respective lugs 46a, 46b that engage in holes 47a, 47b in the inlet passage 10 to locate the cap 32 relative to the inlet passage 10. On assembly1 the circular inlet passage 10 is momentarily distorted into S an oval to allow the lugs 46a, 46b on the cap 32 to pass into the passage 10..

The disc 36 is provided with an aperture 37 to allow the flow of fluid along the inlet passage 10.

The pump fitting described above with reference to the drawings is for connection to a container of liquid 38, part of which is shown schematically in Figures 9 and 10. The container 38 may hold any suitable liquid to be pumped such as, for example, wine.

The term "liquid" is to be taken, however, to encompass liquids such as soups and paints.

The container 38 includes an outlet passage 39 that is cylindrical in shape and which is a mating fit with the inlet passage 10 of the pump fitting. The inlet passage 10 is inserted into the outlet passage 39, with the ribs 35 securing the parts together and providing a seal, This engagement prevents the tube 10 distorting and so the lugs 46a, 46b cannot disengage from the tube 10 so ensuring that the cap 32 is locked to the tube 10.

The exposed end face 45 of the rotor 17 is connected to a drive (not shown), which may be in the form of an electric motor. The drive itself may be controlled by a control system (not shown). The motor rotates the rotor 17 in an anti-clockwise direction as seen in Figures 5 and 6. Starting from the position shown in Figure 5, rotation of the rotor 17 rotates the first chamber 25 around the housing 12 to communicate the first chamber 25 with the outlet passage 11. At the same time, the S second chamber 26 communicates with the inlet passage 10 to receive liquid from the container 38. Further rotation of the rotor 17 conveys the liquid in the second chamber 2 around to the outlet passage 11 at the same time squeezing the liquid from the first chamber 25 through the outlet passage 11.

During this rotation, the diaphragm seal 28 and the tube 31 work together to prevent the passage of liquid from the outlet passage 11 to the inlet passage 10. As seen in Figures 3, 4, 5 and 6, the tube 31 urges the diaphragm seal 28 into contact with the surface of the rotor 17 throughout the rotation of the rotor 17-contacting alternately the housing engaging surfaces 23, 24 of the rotor and the shape surfaces 21,22 of the rotor. As seen in Figures 3 and 4, the shape of the tube ensures that an even pressure is applied to the diaphragm seal 28 along its axial extent.

The control system can be used to control the drive so that the rotor delivers a predetermined volume of liquid at a predetermined flow rate through the outlet passage 11.

The arrangement of the pump housing 12 and the rotor 17 need not be as described above. It could be of any of the types described in PCT/GB2005/003300 and It will be appreciated that the pump fitting provides a simple and inexpensive way of delivering liquid from the container 38. The inlet passage 10 and the outlet passage 11 provide a direct path out of the container 38 interrupted only by the rotor and diaphragm. The pump fitting has few moving parts and so is reliable in operation. In addition, the pump fitting is capable of delivering a measured quantity of liquid with great accuracy so making it suitable for delivering measured quantities of potable liquids such as wine and concentrated liquids. Since the pump fitting is inexpensive to manufacture, it may be provided as a part of the container 38 and disposed of with the container 38 when the container 38 is empty. The rigid outlet passage 39 may be part of a container 38 that is collapsible. It is desirable to evacuate as much of such a container as possible. It is difficult to evacuate any liquid left in this rigid part so incorporating as much of the pump into this volume as possible reduces the dead volume and so improves the utilisation of liquid.

As mentioned above, the inlet passage 10, the outlet passage 11, the diaphragm seal 28 and the pump housing 12 are formed as a one piece moulding in the same moulding process as follows and referring to Figures 11 and 12.

With reference to fig 11 and 12, the moulding process for moulding in one-piece the inlet passage 10, the outlet passage 11 and the pump housing 12 utilises a mould tool with first, second, third and fourth cores 47, 48, 49 and 50. The first core 47 defines the interior of the inlet passage 10 and co-operates with the second core 48 to define the aperture 27 in the pump housing 12. In addition, the first core 47 defines a slot 51 that forms the one-piece moulding with a wall 52 adjacent an edge of the aperture 27. The third core 49 defines a sprue 56 extending from the pump housing 12 and the fourth core 50 engages the third core 49 to form a feed point 55.

Once this part of the moulding has been formed, the first core 47 is retracted as seen in Figure 11 to space it from the second core 48 by the required thickness of the diaphragm seal 28 to form a mould chamber 53. The third core 49 and fourth core SO are also retracted to form a passage 54 leading from the feed point 55 to the mould chamber 53, A molten material suitable to form the diaphragm seal 27 is injected through the feed point 55, through the passage 54 and into the mould chamber 53 to form the diaphragm seal 28 in one-piece with the remaining components.

In this way, whole of the pump fitting can be manufactured as a one-piece moulding using the same cavity in the tool instead of using a twin screw moulding machine for each of the housing and diaphragm materials. This reduces size of the tool and reduces the time for production thereby reducing the cost of the pump fitting.

Referring next to Figures 13 to 19, various modifications to the pump described above with reference to the drawings are possible. Parts common to Figures 1 to 12, on the one hand, and to Figures 13 to 19, on the other, are given the same reference numerals and will not be described in detail.

In the embodiment of Figure 13, the rotor 17 is formed with a drive interface 131 that is a mating fit with a drive shaft of a motor (not shown). The co-operating profiles of the drive shaft and the drive interface 131 are unique to the product being pumped to prevent an incorrect product being fitted to the motor. In addition, the outlet 11 is a tamper-evident cap 132 that is removed before the pump fitting is used.

In the embodiment of Figures 14 and 15, the outlet 11 is modified by the addition of an air inlet tube 141 leading from an open connection 142 to the outlet 11 about halfway along the length of the outlet 11. The axis of the tube 141 is parallel to the axis of the rotor 17, The outlet 11 contains a concentric inner tube 144 closed at one end and opening at a point 145 on the outlet where the diameter of the outlet increases. The open end of the inner tube 144 contains a nozzle 146. The upper end of the inner tube 144 adjacent the closed end communicates with the outlet formed in the housing 12 containing the rotor 17. The increased diameter end portion 147 of the outlet 11 is provided with a pair of discs 143 of mesh or porous material.

The pump of this embodiment is for pumping a flowable material that requires foaming before delivery. Examples are soaps and dairy products that require foaming. The motor driving the rotor 17 is associated with a supply of air or other suitable gas such as nitrogen at, say) 0.138 to 0.344 bar (2 -5 psi). Since the axis of the tube 141 is parallel to the axis of the rotor 17, the connection 142 of the tube 141 can be connected to the supply simultaneously with the connection of the rotor 17 to the drive.

The inlet passage 10 is connected to a container as described above containing flowable material. The material is pumped as described above with reference to Figures ito 12 at the same pressure as the pressure of the gas. The material passes into and along the inner tube 144. At the nozzle 146, the material is formed into a thin radial spray pattern and meets the gas exiting the tube 141 passing between the outlet 11 and the outer surface of the inner tube 144. This occurs at the point where the outlet 11 increases in diameter. This allows the material to mix with the gas and expand. The expanding pressurised gas/material mix passes along the increased diameter portion 147 of the outlet 11 to the discs 143. The mix passes through the mesh/porous material of the discs 143 where it forms a uniform foam with fine bubbles before exiting the outlet 11.

The embodiment described above with reference to Figures 14 and 15 can be used for diluting concentrates. In this case, the inlet tube 141 is connected to a source of water under pressure and the discs 143 are omitted. Where water is used, it may be introduced at a pressure of about 3.1 bar (45 psi) but its pressure will reduce as it passes towards the open end of the outlet 11, which is at atmospheric pressure. The pressure of the water at the point at which it mixes with the concentrate can be adjusted by adjusting the position of the open end of the inner tube 144 along the axis of the outlet 11 This adjustment may be used to reduce the pressure of the water at the point where it mixes with the concentrate -even to the extent that the water has zero pressure at this point. This is advantageous since it is easier to pump the concentrate into a low-pressure zone.

Figures 16, 17 and 18 show a modified version of the embodiment of Figures 14 and 15. In this embodiment, the tube 141 leads to a central tube 151 that is co-axial with the outlet 11. The central tube 151 terminates in a nozzle 152. In use, the embodiment of Figures 16, 17 and 18 is used for pumping food concentrates that contain fibres. The tube 141 is connected to a source of water at a pressure of from, for example, 1.72 bar to 2.76 bar (25 to 40 psi).

The connection is shown in Figure 18. A housing 153 contains a motor (not shown) with an output drive shaft 154 that connects with and drives the rotor 17 of the pump fitting. The housing 153 also contains a pressurised water outlet 155 that receives the open end of the tube 141.

The food concentrate is pumped to the outlet 11 from a container 157 at a pressure high enough to overcome the pressure created by the pressurised water, as described above with reference to the drawings, where it flows in a path co-axial with the flow of water through the central tube 141. The nozzle 152 is configured so that the water exits the nozzle 152 as a high velocity curtain at an angle of between 60° and 900 to the axis of the outlet 11. This curtain of high speed water meets the concentrate at the end of the outlet 11 approximately at right angles and causes extreme agitation. In this way, the liquids can be mixed in a very small space.

The mixed fluids then pass through a laminar flow device 156 of known type to slow the liquid velocity and make the liquid exit in a smooth parallel manner.

The introduction of the water into the centre of the concentrate flow is useful where the concentrate contains fibres. In this case) there must be an uninterrupted path through the outlet 11 for concentrate flow, If the concentrate is introduced into the centre of the outlet 11, it is necessary to support the nozzle 152 and this is S commonly achieved using fins on which the fibres can catch and gradually build up to block the outlet 11.

Figure 19 shows a modification of the embodiment of Figures 16, 17 and 18 in which a gas inlet tube 191 is provided leading to the inlet 11 at a point spaced along the outlet 11 downstream of the tube 141. The gas inlet tube 191 and the water inlet tube 141 have parallel axes. A porous plug 192 is provided in the outlet 11 upstream of the laminar flow device 153.

The gas inlet tube 191 is connected to a supply of gas, such as nitrogen or carbon dioxide, at a pressure of from 2.75 bar to 4.83 bar (40-70 psi).

The pump assembly of Figure 19 is for pumping a concentrate to form a carbonated drink. The concentrate is pumped and mixed with water as described above with reference to Figures 16, 17 and 18. The gas is introduced into the porous plug 192 that provides a large surface area over which the concentrate/water mixture can absorb the gas. The carbonated mixture then exits through the laminar flow device 153.

The laminar flow device 153 may be replaced by a tapered tube (not shown) that slows the carbonated liquid without causing nucleation and the gas to come out of solution. An alternative is a spiral that is the equivalent of a coiled tube that is shaped to slow down the carbonated fluid gradually over the tube length.

Claims

C LAI MS1. A pump fitting for a container of fluid comprising an inlet adaptor for connection to an outlet passage of a container of fluid and including an inlet passage, an outlet passage for fluid and a pump housing between the inlet passage and the outlet passage, the pump housing containing a rotor rotatably received in an interior surface of the housing, the rotor including a housing-engaging surface co-operating with the interior surface of the housing to form a seal therebetween and also including at least one shaped surface radially inwardly of the housing-engaging surface and forming with the interior surface of the housing a chamber for conveying fluid from the inlet passage to the outlet passage on rotation of the rotor, a seal being provided between the outlet passage and the inlet passage, the seal being urged into engagement with the rotor to prevent fluid C') passing from the outlet passage to the inlet passage as the shaped surface rotates, the F'-inlet passage, the outlet passage, the seal and the housing being formed as a one-piece moulding, the outlet passage including a second inlet for passing a second fluid to the inlet passage and a device downstream of the inlet for mixing the fluid from the rotor and the fluid from the second inlet.
2, A pump fitting for a container of fluid comprising an inlet adaptor for connection to an outlet passage of a container of fluid and including an inlet passage, an outlet passage for fluid and a pump housing between the inlet passage and the outlet passage, the pump housing containing a rotor rotatably received in an interior surface of the housing, the rotor including a housing-engaging surface co-operating with the interior surface of the housing to form a seal therebetween and also including at least one shaped surface radially inwardly of the housing-engaging surface and forming with the interior surface of the housing a chamber for conveying fluid from the inlet passage to the outlet passage on rotation of the rotor, a seal being provided between the outlet passage and the inlet passage, means being provided for urging the seal into engagement with the rotor to prevent fluid passing from the outlet S passage passage to the inlet passage as the shaped surface rotates, the means being located at an end of the inlet passage, the outlet passage passage including a second inlet for passing a second fluid to the inlet passage and a device downstream of the inlet for mixing the fluid from the rotor and the fluid from the second inlet.
3. A pump fitting according to claim 1 or claim 2 wherein the outlet passage is generally cylindrical about an axis, an inner tube being provided within and co-axial with the outlet C') passage, one fluid passing along the inner tube and the other fluid passing between the inner tube and the outlet passage, the inner tube having a downstream end within the 0 outlet passage. is
4. A pump fitting according to claim 3 wherein the mixing device comprises a nozzle at the downstream end of the inner tube.
5. A pump fitting according to claim 4 wherein the nozzle is configured so that fluid exits the nozzle as a curtain at an angle of between 60° and 90° to the axis of the outlet passage to mix with fluid passing between the inner tube and the outlet passage.
6. A pump fitting according to any one of claims 1 to 5 wherein the rotor is in fluid communication with the inner tube so that fluid from the rotor passes along the inner tube and the second inlet is in fluid communication with the space between the inner tube and the outlet passage so that fluid from the second inlet passes between the inner tube and the outlet passage.
7. A pump fitting according to any one of claims 1 to 5 wherein the second inlet is in fluid communication with the inner tube so that fluid from the second inlet passes along the inner tube and the rotor is in fluid communication with the space between the inner tube and the outlet passage so that fluid from the rotor passes between the inner tube and the outlet passage.
8. A pump fitting according to any one of claims ito 7 wherein mixing device comprises at least one disc of mesh or porous material. C')
9. A pump fitting according to claim 8 wherein the disc of mesh or porous material also F". foams the mixture.
10. A pump fitting according to any one of claims 1 to 9 wherein the downstream end of the r outlet passage includes a device for imparting a laminar flow to fluid leaving the outlet passage.
11. A pump fitting according to any one of claims 1 to 10 wherein a further inlet tube is provided in the outlet passage downstream of the second inlet for feeding a further fluid to the inlet.
12. A pump fitting according to claim ii wherein the fluids passing from the rotor and the second inlet to the outlet passage are liquids and the further fluid is a gas for carbonating the liquids.
13. A pump fitting according to claim 12 wherein the downstream end of the outlet passage includes a device for slowing the mixed carbonated liquids without causing nucleation.
14. A pump fitting substantially as hereinbefore described with reference to Figures 14 to 19 S of the accompanying drawings. C')N-r