GB2216979A

GB2216979A - Apparatus for cleaning pipelines

Info

Publication number: GB2216979A
Application number: GB8805941A
Authority: GB
Inventors: Raymond Pollock
Original assignee: BAR AND CELLAR SERVICES LIMITE
Current assignee: BAR AND CELLAR SERVICES LIMITE
Priority date: 1988-03-12
Filing date: 1988-03-12
Publication date: 1989-10-18
Anticipated expiration: 2008-03-12
Also published as: GB2216979B; GB8805941D0

Abstract

Apparatus is disclosed for cleaning pipelines eg. beer lines. The apparatus has mixing means 8 having first 17 and second inlets 30 and one outlet 20. In use, the mixing means 8 operates to draw liquid in at the second inlet 30 at a rate dependent on the rate of flow of liquid into the first inlet 17, liquid from both nets 17, 30 emerging from the common outlet 20 to a pump 22. Means is provided for supplying a first liquid to the first inlet 17 and for selectively supplying either the first liquid or a second liquid to the second inlet 30. Relating to beerlines, the first liquid is water 2 and the second liquid is detergent 38. An improvement in accuracy may be obtained because the detergent rate is dependent on the flow rate of the water. A higher flow rate may be obtained because there is no pressure control valve in the water supply. Water and detergent solution are alternately supplied by selecting water 2 via a valve 10 or detergent 38 at the second inlet 30 of the mixing means 8 by a solenoid valve 34. <IMAGE>

Description

APPARATUS FOR CLEANING PIPELINES FIELD OF THE INVENTION This invention relates to apparatus for cleaning pipelines, for example beerlines.

BACKGROUND OF THE INVENTION Pipelines may be cleaned by alternately passing cleaning liquid and flushing liquid therethrough. To clean beer lines, the line is first flushed through with water, then filled with a detergent solution and allowed to soak, then flushed through again with water. The process may be repeated and the soak time may be reduced or removed by passing detergent solution trough the line for a period after the line is full of the solution.

The process has been performed manually and automatically. Apparatus for performing the process automatically may either mix water and detergent in a large reservoir at the start and then pump it into the beerline, or may mix the two as the beerline is filled. In the latter case, the proportions of detergent and water have been obtained by passing the water supply through a pressure control valve to control the rate of flow of the water, and supplying the detergent with a dosage pump. Inaccuracies arise because the rate at which detergent is supplied by the dosage pump is independent of the actual flow rate of the water. Using a pressure control valve means that the flow rate is inherently less than could be obtained with an unrestricted uncontrolled supply.

SUMMARY OF THE INVENTION In accordance with the invention there is provided apparatus for cleaning pipelines, comprising: mixing means having first and second inlets and a common outlet, in use, the mixing means operating to draw liquid in at the second inlet at a rate dependent on the rate of flow of liquid into the first inlet, a mixture of liquids from both inlets emerging from the common outlet; means for supplying a first liquid to the first inlet and a second liquid to the second inlet; and valve means for selecting either the first liquid only or the mixture to be supplied to the common outlet.

Preferably, the means for selecting includes means for selectively supplying either the first liquid or a second liquid to the second inlet of the mixing means.

The apparatus may be used to clean other pipelines besides beerlines. However, relating to beerlines, the first liquid is water and the second liquid is detergent. An improvement in accuracy may be obtained because the detergent rate is dependent on the flow rate of the water. A higher flow rate may be obtained because there is no pressure control valve in the water supply. Water and detergent solution are alternately supplied, in the preferred form, by selecting water or detergent at the second inlet of the mixing means.

Suitable mixing means include a venturi tube having a first inlet leading through a constriction to an outlet, and a second inlet to the constriction, so that the reduced pressure as the first liquid flows through the constriction draws in the second liquid from the second inlet.

A highly accurate mixing means is in the form of a Dosatron liquid dispenser, manufactured by Hingerose Limited, 162 Blanford Avenue, Kettering, Northamptonshire NN16 9A8.

The dispenser is described in US patent specification No.

3,937,241 and has a stepped piston in a stepped cylinder. A valve in the piston is triggered to open and close at opposite ends of the piston travel to cause a reversal of piston movement. A further piston moved by the first pumps metered quantities of an adjuvant into the stepped cylinder.

Preferably, the means for selectively supplying either the first liquid or a second liquid to the second inlet includes a pressure reducing valve connecting the inlet to the means for supplying the first liquid to the first inlet.

The means for selectively supplying preferably includes a three way solenoid valve having one inlet connected to the means for supplying the first liquid, a second inlet for the second liquid, and a common outlet connected to the second inlet of the mixing means.

The apparatus may include a controller arranged to operate the solenoid valve to provide the first liquid only or a mixture of the two liquids alternately.

The apparatus preferably includes a two way solenoid valve in the means for supplying the first liquid, and wherein the controller is arranged to operate the two way solenoid valve to allow a soak period between the provision of mixture and the first liquid only.

One of the problems in using automatic apparatus, is that it may be unknowingly operated when the detergent container is empty. An alternative aspect of the invention provides apparatus for cleaning pipelines, including means for drawing a cleaning liquid from a container, a probe comprising a pair of spaced conductors, and a controller arranged to detect conduction between the two conductors, and to inhibit operation of the apparatus if conduction is not detected.

The probe preferably includes a tube for drawing the second liquid.

In one form the conductors are conducting rods. A problem with this arrangement is that unless extreme care is taken, the ends of the rods and the tube can become so close that detergent remains bridging the rods and the tube, creating a circuit between the rods, even when the level of the liquid is below that of the rods. To avoid this the rods and tubes may be held apart by a separator, the separator including surfaces having sufficient slope in their working position, that liquid remaining on the separator does not bridge the gap between the conductors, once the general liquid level is below the separator.

The separator may comprise a generally horizontal part bridging the rods and the tube in the working position, and sleeves extending up the rods from the generally horizontal part to isolate the rods from any liquid remaining on the generally horizontal part.

One of the problems faced by the management of licensed premises (e.g. the brewer in the case of a tied house) is to be sure that the beerlines have been cleaned as often as they ought. To this end the apparatus may include including a counter arranged to count the number of times the apparatus is used.

The invention also extends to a probe for detecting a minimum level of a suitably electrically conducting liquid, comprising a plug or body from which extend two conducting rods and a tube through which the liquid may be withdrawn.

The rods and tubes may be held apart by a separator, the separator including surfaces having sufficient slope in their working position, that liquid remaining on the separator does not bridge the gap between the conductors, once the general liquid level is below the separator.

The separator preferably comprises a generally horizontal part bridging the rods and the tube in the working position, and sleeves extending up the rods from the generally horizontal part to isolate the rods from any liquid remaining on the generally horizontal part.

BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic drawing showing fluid and electrical circuits of apparatus embodying one aspect of the invention; and Figure 2 is a side view of a probe embodying another aspect of the invention.

DETAILED DESCRIPTION The apparatus illustrated in Figure 1 is nominally for cleaning beerlines with water and detergent. It may equally be used or adapted for use to clean other pipelines using the same or other liquids.

Referring to Figure 1, the apparatus is connected at 2 to a water main or other source of water under pressure. A vented non-return valve 4 prevents water from siphoning back into the main. The water supply is controlled by a solenoid valve 6 to a first inlet of a mixing means 8 and an inlet of a pressure reducing valve 10. An outlet 20 of the mixing means is connected to a pump 22 or direct to the beerline to be cleaned if the water pressure is sufficiently high.

In the preferred embodiment of the invention, the mixing means is a device such as described in detail in US patent specification No. 3,937,241. The device has a stepped cylinder inside which a stepped piston reciprocates under the control of valves (not illustrated) carried by the piston. A first valve allows liquid to pass through the piston from the smaller part of the cylinder to the larger. A second valve allows liquid to from one side 16 to the other side 18 of the piston within the larger part of the stepped cylinder.

In the upward stroke of the piston, as seen in the drawing, the first valve is closed and the second is open so that water pressure in the larger part of the cylinder is relieved by the second valve. As the first valve is closed, pressure of water supplied at a first inlet 17, in the smaller part of the cylinder, urges the piston 14 upwards and water in the larger part of the cylinder on the side 16 of the piston is forced through the second valve and through an outlet 20 to a pump 22.

When upward movement of a slidable rod 24 is arrested by the upper end of the cylinder 12, continued upward movement of the piston 14 relative to the rod 24 switches the valves by a mechanism not shown, so that the first valve is open and the second is closed.

Full water pressure now exists in both the smaller part of the stepped cylinder and in the larger part 16 on the upper side of the piston. In the larger part of the cylinder on the side 18 of the piston, the pressure is relieved to the outlet 20, however. Due to there being a greater area of the upper side of the piston 14 in contact with the higher pressure water the piston moves downwardly. Water flows through the first valve from the smaller part if the stepped cylinder to the larger part of the cylinder on the side 16 of the piston 14. Water displaced in the larger part of the cylinder on the side 18 of the piston as it moves downwardly, is forced through the outlet to the inlet of the pump 22.

Downward movement of the rod 24 is next arrested by the bottom of the cylinder. This switches the valves back over so that the first valve is closed and the second is open causing upward movement as already described. And so the piston cycles repeatedly through upward and downward strokes.

A further piston depends from the piston 14 in a small diameter cylinder 25. This further piston has the form of a plunger 26 having a resilient conical or cup-shap"ed seal 28 at its end in the manner of a bicycle pump. As the piston 14 moves upwardly, the plunger 26 draws in liquid from a second inlet 30 opening a non-return valve 32. When the piston 14 moves downwardly, the non-return valve 32 closes forcing the liquid in the cylinder 25 past the conical or cup shaped seal. Next time the plunger 26 moves upwardly, this liquid is pumped into the stepped cylinder 12.

The inlet 30 of the mixing means is connected to a common outlet of a three way solenoid valve. One inlet of the solenoid valve 34 is connected to a suction tube in a container of detergent 38. Another inlet of the solenoid valve 34 is connected to an outlet of the solenoid valve 10.

A controller 40 is arranged to control the solenoid valves 4 and 34. A flushing cycle is obtained with the solenoid valve 4 open and the solenoid valve 34 switched to allow water via the pressure reducing valve 10 to the second inlet 30 of the mixing means. Although the mixing means does pump liquid from the inlet 30 into the cylinder 12 and thus to the pump 22, the liquid supplied to the inlet 30 is water so the beerline has a detergent free flush.

To fill the beerline with detergent solution, the solenoid valve 34 is switched so that detergent is supplied from the container 38 to the inlet 30. Detergent is now pumped into the cylinder 12 by the plunger 26, so that detergent solution is delivered to the pump 22. The proportion of detergent in the solution depends on the relative sizes of the cylinder 12 and the cylinder 25 and whether there is any lost motion between the piston 26 and the piston 14.

Once the beerline is full, it is allowed to soak in detergent for a period determined by the controller. This is achieved by closing the solenoid valve 4.

The controller is preferably programmed to cycle the apparatus through the following steps: flush, fill the beerline with detergent, soak, fill again with new detergent mix, soak, flush.

In an alternative arrangement, not illustrated, the inlet 30 is permanently (i.e. not selectively) connected to the detergent container 38. A three way solenoid valve is provided to supply water from the mains via the valves 6 and 4, either to the inlet 17 of the mixing means, or direct to the common outlet 20.

In order to ensure that there is enough detergent left to perform a full cycle, the suction tube 36 is part of a probe assembly illustrated in Figure 2. The suction tube 36 extends through a plug 42 intended to fit a neck 44 of the container 38. Extending from the plug, one on each side of the tube 36, are two conductors in the form of stainless steel rods 46 and 48. The rods are connected electrically, inside the plug 42, each to a conducting core of an electrical lead 50. The lead is connected to the controller which detects conduction between the two leads provided by detergent bridging the gap between the conducting rods 48.

If the detergent level falls below a level at which it can bridge the gap between the rods, conduction is no longer detected by the controller and a new cleaning cycle is not allowed to start.

If the rods 46,48 and or the tube 36 become distorted it is possible for them to be sufficiently close that detergent remains, held by surface tension and bridging the gap between the rods, even when the actual detergent level in the container has fallen below the level of the ends of the rods.

To reduce the possibility of such an event, the rods 46,48 and the tube 36 are spaced apart by a separator 52 which has the form of a disc in a plane normal to the paper. It would clearly be undesirable for detergent remaining on the separator 52 to bridge the gap between the conducting rods 46,48 and to prevent this the rods each pass through one of two sleeves 54 and 56 which extend upwardly from the disc 53.

The sleeves may be separate from the disc 53, in which case they also need to extend below the disc as illustrated.

Essentially, the sleeves provide a surface between the rods which is sufficiently sloping (in this case approximately vertical) that detergent cannot remain on it to bridge the gap between the rods. Other arrangements may be envisaged, for example the disc could itself slope at an angle to the horizontal sufficient that insufficient detergent remains to bridge the gap between the rods.

Returning to Figure 1, a counter 58 is shown connected to the controller. Each time the apparatus is used the counter is indexed by one, so that a manager inspecting a cellar can determine how often the apparatus has been used.

Claims

1. Apparatus for cleaning pipelines, comprising: mixing means having first and second inlets and a common outlet, in use, the mixing means operating to draw liquid in at the second inlet at a rate dependent on the rate of flow of liquid into the first inlet, a mixture of liquids from both inlets emerging from the common outlet; means for supplying a first liquid to the first inlet and a second liquid to the second inlet; and valve means for selecting either the first liquid only or the mixture to be supplied to the common outlet.

2. Apparatus as claimed in claim 1, wherein the means for selecting includes means for selectively supplying either the first liquid or a second liquid to the second inlet of the mixing means.

3. Apparatus as claimed in claim 2, wherein the means for selectively supplying either the first liquid or a second liquid to the second inlet includes a pressure reducing valve connecting the inlet to the means for supplying the first liquid to the first inlet.

4. Apparatus as claimed in claim 2 or 3, wherein the means for selectively supplying includes a three way solenoid valve having one inlet connected to the means for supplying the first liquid, a second inlet for the second liquid, and a common outlet connected to the second inlet of the mixing means.

5. Apparatus as claimed in claim 4, including a controller arranged to operate the solenoid valve to provide the first liquid only or a mixture of the two liquids alternately.

6. Apparatus as claimed in claim 5, including a two way solenoid valve in the means for supplying the first liquid, and wherein the controller is arranged to operate the two way solenoid valve to allow a soak period between the provision of mixture and the first liquid only.

7. Apparatus as claimed in claim 6, including a probe, comprising a pair of spaced conductors, the comptroller being arranged to detect conduction between the two conductors, and to inhibit operation of the apparatus if conduction is not detected.

8. Apparatus as claimed in claim 7, wherein the probe includes a tube for drawing the second liquid.

9. Apparatus as claimed in claim 8, wherein the conductors are conducting rods, the rods and tubes being held apart by a separator, the separator including surfaces having sufficient slope in their working position, that liquid remaining on the separator does not bridge the gap between the conductors, once the general liquid level is below the separator.

10. Apparatus as claimed in claim 9, wherein the separator comprises a generally horizontal part bridging the rods and the tube in the working position, and sleeves extending up the rods from the generally horizontal part to isolate the rods from any liquid remaining on the generally horizontal part.

11. Apparatus as claimed in any preceding claim, wherein the means for supplying the first liquid includes a vented non-return valve for connection to a water main.

12. Apparatus for cleaning pipelines, including means for drawing a cleaning liquid from a container a probe comprising a pair of spaced conductors, and a comptroller arranged to detect conduction between the two conductors, and to inhibit operation of the apparatus if conduction is not detected.

13. Apparatus as claimed in claim 12, wherein the probe includes a tube for drawing the second liquid.

14. Apparatus as claimed in claim 13, wherein the conductors are conducting rods, the rods and tubes being held apart by a separator, the separator including surfaces having sufficient slope in their working position, that liquid remaining on the separator does not bridge the gap between the conductors, once the general liquid level is below the separator.

15. Apparatus as claimed in claim 14, wherein the separator comprises a generally horizontal part bridging the rods and the tube in the working position, and sleeves extending up the rods from the generally horizontal part to isolate the rods from any liquid remaining on the generally horizontal part.

16. Apparatus as claimed in any preceding claim, including a counter arranged to count the number of times the apparatus is used.

17. A probe for detecting a minimum level of a suitably electrically conducting liquid, comprising a plug or body from which extend two conducting rods and a tube through which the liquid may be withdrawn.

18. A probe as claimed in claim 17, wherein the rods and tubes are held apart by a separator, the separator including surfaces having sufficient slope in their working position, that liquid remaining on the separator does not bridge the gap between the conductors, once the general liquid level is below the separator.

19. Apparatus as claimed in claim 18, wherein the separator comprises a generally horizontal part bridging the rods and the tube in the working position, and sleeves extending up the rods from the generally horizontal part to isolate the rods from any liquid remaining on the generally horizontal part.