GB2122980A - Method and apparatus for cleansing containers - Google Patents

Abstract

Apparatus for cleansing a container 13 e.g. a metal beer keg arranged with its aperture facing downwards comprises a U-tube 17 disposed in a tank 10 of cleansing liquid, and a platform 14 in the form of a grid on which the container is located and which is lowered into the liquid so that the inner limb of the U- tube 17 projects into the container through the aperture and enables the air within the container to pass to atmosphere so that the container fills with the cleansing liquid. The liquid is then subjected to ultrasonic vibration by vibrators 11 attached to the tank to loosen deposits within the container. Compressed air is then passed through the U-tube into the container to displace the liquid, and the platform 14 and container are raised out of the liquid. The container is then passed to a water spray cleansing apparatus in which the container is placed on a rotating turntable 23 under a hood 24 while cleansing water is sprayed over the interior of the container through a spray nozzle 27 which is reciprocated lengthwise of the container, and onto the container end via a radially movable nozzle 31. Rinse water is sprayed into the container through a fixed angled nozzle 33 and over the exterior of the container by a vertical array of nozzles 35. <IMAGE>

Description

SPECIFICATION Method and apparatus for cleansing containers This invention relates to container cleansing apparauses and methods. The invention is particularly but by no means exclusively useful in the cleansing of metal beer kegs.

Metal beer kegs are commonly made of aluminium alloy or stainless steel and are barrelshaped with chimes or shoulders at each end, one of the functions of the chimes at one end being to protect the protruding neck of the single aperture to the container and the spear or insert which in use is screwed into the neck of the container. The spear has two passages, one of which in use permits carbon dioxide to be admitted to the keg to expel beer through the other. The kegs are typically cleaned by several rinses, which may include cold water, hot water, water with detergent or steam. These operations are all carried out through the spear and they may be carried out in-line with the keg filling operation.

Where kegs are used and returned regularly to the brewery, this known system may be satisfactory. Where however kegs are not in regular circulation between customer and brewery, build up of scale known as beer stone may occur and this is typically not satisfactorily removed by devices which apply cleansing fluids via the spear. It should be noted that other containers may be cleansed by suitable modifications to the method and apparatus hereinafter described. For example, a cask which has an aperture at one end and an aperture along its curved wall may be treated by suitable modifications to the equipment described.

According to one aspect of the invention there is provided a container cleansing apparatus comprising a tank containing cleansing liquid into which a container is placed, venting means insertable into an aperture in the container for the removal of gas trapped by the cleansing liquid in the container, means for applying an ultrasonic field to the cleansing liquid thereby to assist in the cleansing process, and means for admitting gas under pressure to the interior of the container to assist in expelling the cleansing liquid from the container.

The invention also provides a method of cleansing a container having an aperture at one end or side, said method comprising immersing the container with the aperture facing downwardly in a tank containing cleansing liquid, bleeding gas trapped in the container from the interior of the container to permit the interior of the container to fill with the liquid, applying an ultrasonic field to the liquid in the tank, admitting gas to the interior of the container to assist in the expulsion of the liquid from the container, and removing the container from the tank.

Preferably said venting means comprises a tube through which said gas is removed and an ejector nozzle is disposed in the tube which ejector nozzle is connected to be supplied with air under pressure and is directed to cause the air to flow in a direction away from the container. Conveniently said tube may incorporate a valve downstream of the ejector nozzle which valve is selectively openable and closable to permit and to stop the flow of air and gas from the tube, whereby when the valve is closed air under pressure supplied to the ejector nozzle flows through the tube to the interior of the container to expel cleansing liquid therefrom.

According to another aspect of the invention there is provided a container cleansing apparatus comprising means for locating a container, which container has an aperture facing downwardly, relative to a liquid directing nozzle, means for inserting said liquid directing nozzle through the aperture into the interior of the container, means for applying cleansing liquid to the container under pressure through said nozzle and means for moving the nozzle upward and downward within the container.

The invention will now be described in more detail with reference by way of example to the accompanying diagrammatic drawings, in which: Figure 1 is a side elevation of a cleansing apparatus according to the invention with a container shown at the commencement of immersion; Figure 2 corresponds to Figure 1 but shows the container fully immersed; Figure 3 illustrates a modification of the arrangement as shown in Figures 1 and 2, Figure 4 shows a detail of the modification of Figure 3, and Figure 5 is a side elevation of the cleansing apparatus of Figure 1 linked by a container transfer device to a second form of cleansing apparatus according to the invention.

Referring first to Figures 1 and 2, the cleansing apparatus shown comprises an open-topped metal tank 10 having ultrasonic transducers 11 of conventional type mounted around its vertical walls below the level 50 of the cleansing liquid contained in tank 10. The cleansing liquid is water having detergent and suitable additives according to the nature of the materials to be cleansed from the container, the liquid being heated by means of a heater 12, located near the bottom of tank 10, to a suitable temperature which can be controlled by a thermostat (not shown).

The container to be cleansed is in this instance an empty beer keg 13, which has previously had its spear removed. The keg is located, with its spear aperture facing downwardly, on a horizontal open grid platform 14 and has its chimes or shoulders 21 resting against a stop 1 5.

Alternatively and preferably, keg 13 may be located by having the protruding neck about its spear aperture engaged by a device positioned on platform 1 4. In order positively to hold keg 1 3 to platform 14, an additional device attached to platform 14 may be incorporated which interposes a member between the outer lip of the protruding neck and the body of ket 1 3 to clamp the keg to the platform; alternatively, a member may engage the base of the inverted keg to clamp the keg to the platform.The platform 14 can be lowered into and raised from the tank by any convenient means indicated at 1 6. A U-shaped venting tube 17 extends downwardly into the liquid in tank 10 adjacent its perimeter, and then upwardly in the central region of the tank 10 so that before the keg 13 is immersed the U-tube 17 is above the liquid with its end open to atmosphere. The position of platform 14 is such that the open end of the U-tube 17 will pass through the open grid of platform 14 and into the spear orifice of the keg 13 located on platform 14 as the platform is lowered. To accommodate different keg sizes the position of the stop 1 5 may be adjustable relative to platform 14 so that the keg 13 can be correctly located relative to the open end of the U-tube 17.

The U-tube 17 is suspended in tank 10 by means of a wire cord connected to the upper end of the tube and extending over a pulley mounted on the tank, a counterweight being connected to the other end of the cord. Thus kegs of differing sizes can be emptied of air without adjusting the limits of travel of the platform. Only a minimal load is thus applied to the inner surface of keg opposite; the spear orifice (see dashed outline in Figure 2).

The open end of the U-tube is fitted with a soft nose-piece which is open at the top but has one or more slots or notches 1 7a opening to its top edge, as shown in Figure 3, so that the interior of keg 13 will not be scratched by the U-tube 17. To accommodate the movement of U-tube 17, flexible lines are fitted between valve 1 8 and the compressed air supply 20 and also between valve 1 8 and the suction pump (if employed).

The outer end of the U-tube is connected to a valve 18 capable of being switched into a first position venting the tube to atmosphere through a pipe 19, and into a second position in which the U-tube 1 7 is connected to a compressed air supply 20. If desired a suction pump (not shown) may be connected in the pipe 19 to draw air through the U-tube.

The cleansing cycle commences as the platform 14 is controllably lowered into the liquid in tank 10. The open end of the U-tube 17 enters the spear orifice of keg 13 and as platform 14 continues to be lowered, gas or air trapped inside keg 13 is vented to atmosphere via U-tube 17 and valve 18, assisted if required by the suction pump referred to above. When keg 13 is fully immersed, the nose-piece on the open end of U-tube 1 7 will be in contact with the interior surface of the end ol the keg 13 opposite the spear orifice, thereby enabling all the gas or air to be removed from inside the container (see Figure 2).

The keg 1 3 is immersed in the heated liquid in tank 10 for a predetermined period of time such that the ultrasonic and detergent action can remove as much residue, beer stone, and other deposits from the interior of keg 1 3 as practicable within the economics of operation. Valve 18 is then switched so that compressed air is passed through the U-tube 17 into keg 13, and the platform commences to rise, gradually lifting the keg substantially clear of the liquid in tank 10, the U-tube returning to its original position by means of the counterweight.

Keg 13 is now taken off platform 14 onto a container transfer table 22 which may have a lowfriction surface to ease its movement along the table 22 to a second cleansing apparatus which can be seen in Figure 5.

Figures 3 and 4 illustrate a modification of the apparatus of Figures 1 and 2. In this modification the U-tube 17 has connected into its downstream portions 1 7b, through a flexible pipe section 1 7a, - a pneumatically operated sleeve valve 41 which is selectively operable to open and close off flow from the U-tube to atmosphere. Upstream of the sleeve valve 41 the outlet end portion of a compressed air pipe 42 is mounted centrally within the U-tube and opens to the throat of a venturi section in the pipe so as to form therewith an ejector nozzle 43 directed away from the container. Compressed air is supplied to the pipe 42 through a solenoid operated valve 44. When both of the valves 41, 44 are open, the ejector nozzle operates to extract air and gas rapidly from the container.When liquid commences to flow through the outlet of the tube 1 7, all the air and gas has been extracted from the container, and the cleansing process can continue. The solenoid valve 44 is left open throughout the cleansing operation, and the outlet end of pipe portion 1 7b is disposed over the tank 10 so that the liquid is returned to the tank. When the cleansing process carried out in the tank has been completed, the sleeve valve 41 is closed but valve 44 remains open so that the compressed air flows into the container to displace the cleansing liquid.

Referring now to Figure 5 of the drawings, the second cleansing apparatus comprises a rotatable annular turntable 23 driven by means (not shown) located beneath a raisable hood 24. The turntable 23 is at the same height as the low friction surface of transfer table 22 so that a keg 13 can be slid onto turntable 23 in the same orientation as it leaves the first cleansing apparatus, namely with its spear orifice pointing downwardly. Turntable 23 can be equipped with a keg locating device (not shown) adapted so that the keg 1 3 can be positioned centrally on turntable 23 or alternatively this can be carried out manually. A pneumatically or hydraulically operable platform and cylinder device 25 is positioned centrally below turntable 23 and carries a retractable boom 26 connecting a pair of nozzles 27 at its free end to a flexible high pressure hose 28. Nozzles 27 are each designed to produce a fan jet so that liquid under high pressure can be directed through them onto both the internal side wall and both internal ends of keg 13. Piston and cylinder device 25 is contrallable to raise and lower boom 26 slowly, or more quickly in a reciprocating mode. A second hydraulically operable piston and cylinder device 29, extending substantially horizontally adjacent turntable 23, carries a horizontal boom 30 extending underneath turntable 23. A liquid nozzle 31 adapted to throw a fan jet of high pressure liquid upwardly within the interior of turntable 23 is positioned on the end of boom 30 and is connected by flexible high pressure hose to high pressure liquid line 51.The second piston and cylinder device 29 is controllable to reciprocate nozzle 31 within the interior of turntable 23 to direct high pressure liquid substantially over a radius of the end of keg 1 3 from its spear orifice to its shoulder.

A stationary rinse water line 32 is also positioned beneath turntable 23 (at an angle to the boom 30) and carries a nozzle or nozzles 33 for directing rinse water onto the end of keg 1 3 and into the interior of keg 1 3 through its spear orifice. Rinse water line 32 and nozzle 33 are supplied with fresh water via valve 34 which also feeds water to a vertical array of fan jet nozzles 35 located on an arm extending upwardly adjacent turntable 23 with hood 24. A fixed boom carries an array of fan jet nozzles 35 arranged to direct fresh water onto the side of keg 1 3 and onto the external surface of its end opposite the spear aperture.

Heated cleansing liquid from tank 10 of the first cleansing apparatus is supplied to the nozzles 27 on retractable boom 26, and to nozzle 31 on the reciprocating boom 30. The liquid passes from tank 10 through a filter 36 and a high pressure pump 37 to these nozzles, the cleansing liquid being at a pressure which may be 1000 lb/sq.in. or greater. Lower pressures may be used for cleansing containers having residues which are less resistant to removal. A collection tray 38 beneath turntable 23 is used to collect spent cleansing liquid which is then directed by valve 39 and pump 40 or flows by gravity back into tank 10 of the first cleansing apparatus. Valve 39 is controllable so that when rinse water only is falling into collection tray 38, the rinse water can be directed to drain instead of to tank 10.

In operation of the second cleansing apparatus, hood 24 is raised to admit a keg 13 from transfer table 22. Keg 13 is located centrally on turntable 23 and hood 24 is then lowered to protect the machine operator and to contain the spray. Piston and cylinder device 25 is operated to raise the boom 26 and nozzles 27 through the spear orifice into keg 1 3 whereby high pressure liquid is directed at the interior of keg 13. At the same time the turntable 23 rotates keg 13 enabling the whole of the interior of keg 13 to be reached by the fan jets from nozzles 27. The exterior lower end of keg 1 3 is also cleaned by reciprocating jets of high pressure liquid from nozzle 31 on horizontal boom 30. Spent liquid is returned to tank 10 by the means described above.

After a predetermined interval of time the application of cleansing liquid under pressure is stopped, and boom 26 is withdrawn from keg 13.

Cold rinse water from a mains source is now passed via valve 34 to both the vertical array of nozzles 35 and by line 32 to nozzle or nozzles 33.

The turntable 23 continues to rotate, and rinse water is thus directed at the exterior of keg 1 3 and upwardly into the interior of keg 13 from nozzle or nozzles 33 to remove residual cleansing liquid from the keg. The spent rinse water is directed to drain from the collection tray 38 by valve 39.

After a predetermined rinse period, the cold water supply is shut off, the turntable 23 stopped, and the hood 24 can now be raised to enable the keg to be removed from the second cleansing apparatus.

It will be understood that in some constructions, the keg or other container rests on a fixed platform and the jets are arranged to rotate about the central axis of the container.

One of the advantages of using the two cleansing apparatuses linked in the manner described above is that the pressure liquid jets in the second apparatus can be used to remove any beer stone residue which has been disturbed but not removed in the first cleansing apparatus. It has also been found that the high pressure liquid jets directed at the external end of keg 1 3 adjacent the spear orifice are able to assist significantly in the removal of adhesive labels and adhesive residues which are difficult to remove by other means. The final rinse provides a keg which can be returned to service.

The second cleansing apparatus may be used more frequently on kegs than the first apparatus. It may therefore be separate from the first cleansing apparatus, and in a cleansing plant there could be a plurality of installations of the second cleansing apparatus for each first cleansing apparatus with separate feed table systems for supplying kegs to be cleaned. The second cleansing apparatus may be used at one station followed by a rinse, or rinse and sterilisation process at a second station.

Cleansing plants may incorporate several of any of these arrangements operating in parallel.

Claims (14)

1. - i.A container cleansing apparatus comprising a tank containing cleansing liquid into which a container is placed, venting means insertable into an aperture in the container for the removal of gas trapped by the cleansing liquid in the container, means for applying an ultrasonic field to the cleansing liquid thereby to assist in the cleansing process, and means for admitting gas under pressure to the interior of the container to assist in expelling the cleansing liquid from the container.
2. 2. Apparatus as claimed in Claim 1 wherein the means for admitting gas to the interior of the container employs a conduit which constitutes also part of said venting means.
3. 3. Apparatus as claimed in Claim 1 or Claim 2 comprising means for lowering the container into and raising it out of the tank.
4. 4. Apparatus as claimed in any one of the preceding claims, wherein the venting means comprises a vertical tube arranged to project upward into the container through said aperture, said tube being capable of a degree of downward movement resiliently from a predetermined position into which it is biased.
5. 5. Apparatus as claimed in any one of the preceding claims, wherein said venting means comprises a tube through which said gas is removed and wherein an ejector nozzle is disposed in the tube which ejector nozzle is connected to be supplied with air under pressure and is directed to cause the air to flow in a direction away from the container.
6. 6. Apparatus as claimed in Claim 5, wherein said tube incorporates a valve downstream of the ejector nozzle which valve is selectively openable and closable to permit and to stop the flow of air and gas from the tube, whereby when the valve is closed air under pressure supplied to the ejector nozzle flows through the tube to the interior of the container to expel cleansing liquid therefrom.
7. 7. Container cleansing apparatus substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 2, or in Figures 1 and 2 as modified by Figures 3 and 4 of the accompanying drawings.
8. 8. A container cleansing apparatus as claimed in any one of Claims 1 to 7 comprising, at a different station from said tank, mans for locating a container, which container has an aperture facing downwardly, means for inserting one or more liquid directing nozzles through the aperture into the interior of the container, means for applying cleansing liquid to the container under pressure through said nozzle or nozzles and means for moving the nozzle or nozzles upward and downward within the container.
9. 9. Apparatus as claimed in Claim 8 wherein said means for moving the nozzle or nozzles upward and downward within the container operates to reciprocate the nozzle or nozzles continuously.
10. 10. Apparatus as claimed in Claim 8 or Claim 9 including at said different station a plurality of further nozzles which can be located internally of the container so as to direct liquid substantially over one internal dimension of the container.
11. 11. Apparatus as claimed in Claim 10, wherein said further nozzles include at least one nozzle directed at the exterior of the container in the vicinity of the aperture through which the internally directed nozzle or nozzles is/are admitted to the container.
12. 12. Apparatus as claimed in any one of Claims 8 to 11 wherein a turntable is provided at said different station on which turntable the container can be rotated about an axis of symmetry whilst high pressure liquid is directed through the nozzles at the container.
13. 13. A container cleansing apparatus as claimed in any one of Claims 8 to 12 comprising a container transfer device for transferring the container from the tank to said different station.
14. 14. A method of cleansing a container having an aperture at one end or side, said method comprising immersing the container with the aperture facing downwardly in a tank containing cleansing liquid, bleeding gas trapped in the container from the interior of the container to fill with the liquid, applying an ultrasonic field to the liquid in the tank, admitting gas to the interior of the container to assist in the expulsion of the liquid from the container, and removing the container from the tank.