GB2260795A - Automatic sterilizing/flushing system to be used on liquid dispensing installations - Google Patents

Abstract

Apparatus for flushing and/or sterilizing a conduit (40) adapted to convey a liquid such as beer, comprises a conduit system for connection to such a conduit (40) and adapted to be connected to a supply of water at pressure, a container (53) for containing a sterilizing fluid, and means (57) for pressurizing sterilizing fluid in the container (53) to deliver the fluid to said conduit system, the system including control means (21, 22, 23, 24, 29, 50, 51, 31, 32, 33, 34) to allow or stop flow of water, and to control the rate of flow of water, the flow path of water and the duration of flow of water and to allow or stop the flow of the sterilizing fluid, the rate of flow of sterilizing fluid and the duration of flow of the sterilizing fluid, and electrical means (Figure 1) for selectively controlling the operation of the control means, such that, in use, water is caused to flow through said conduit (40) for a predetermined period of time and/or sterilizing fluid from the container (53) is supplied under pressure into said conduit (40) and the cleaning fluid allowed to remain in the said conduit (40) for a predetermined period, the cleaning fluid thereafter being flushed from the said conduit by means of water. <IMAGE>

Description

AUTOMATIC STERILIZING/FLUSHING SYSTEM TO BE USED ON LIOUID DISPENSING INSTALLATIONS This invention relates to an apparatus whereby the regular flushing and sterilizing of supply conduits and dispensing hardware is automated, significantly reducing the human labour element, possible sources of microbial and bacterial infection, and controlling the levels of wastage during these procedures.

It is to be understood that the term "conduit" as used herein embraces pipes, lines, tubes and other like means for the conveyance of fluids, in particular but not exclusively liquids such as beer.

The apparatus, as described, is specifically designed for use in the dispensing of real ales (cask conditioned beers). However, it is envisaged that the principles used may be applied equally effectively to the dispensing of many other liquids, e.g. food products.

At present, methods of flushing and sterilizing supply conduits employed throughout the brewing and licensed trade outlets are labour-intensive and, if not correctly applied or supervised, involve wastage of time and product.

The present invention is intended to obviate these disadvantages.

According to a first aspect of the present invention there is provided apparatus for flushing and/or sterilizing a conduit adapted to convey a liquid such as beer, which apparatus comprises a conduit system for connection to such a conduit and adapted to be connected to a supply of water at pressure, a container for containing a sterilizing fluid, and means for pressurizing sterilizing fluids in the container to deliver the fluid to said conduit system, the piping system including control means to allow or stop flow of water, and to control the rate of flow of water, the flow path of water and the duration of flow of water and to allow or stop the flow of the sterilizing fluid, the rate of flow of sterilizing fluid and the duration of flow of the sterilizing fluid, and electrical means for selectively controlling the operation of the control means, such that, in use, water is caused to flow through said conduit for a predetermined period of time and/or sterilizing fluid from the container is supplied under pressure into said conduit and the cleaning fluid allowed to remain in the said conduit for a predetermined period, the cleaning fluid thereafter being flushed from the said conduit water.

According to a second aspect of the present invention there is provided a method of flushing and/or sterilizing a conduit adapted to convey a liquid such as beer, which method comprises passing water at pressure through said conduit for a predetermined period of time; and/or injecting a sterilizing fluid under pressure into said conduit allowing the cleaning and/or sterilizing fluid to remain in the said conduit for a predetermined period of time and thereafter flushing said sterilizing fluid from said conduit by means of water.

In both the apparatus and the method of the invention the water may be supplied direct from a water main, the pressure of which may be variable, or from a header tank or other source. The water must be under sufficient pressure to flow through the conduit system to flush the conduit.

A preferred apparatus according to the present invention is comprised of a combination of electronic and hydraulic control. The major components can be broken down into three sections.

1) Electronic control.

2) Water supply and hydraulic flushing.

3) Hydraulic cleaning.

An apparatus according to the invention is described below by way of example with reference to the accompanying drawings, wherein; Figure 1 is a schematic diagram of electrical control circuitry of the apparatus; and Figure 2 is a schematic diagram of a fluid flow system of the apparatus.

The apparatus shown in the drawings is particularly intended for use with a real ale dispensing system. The apparatus comprises a control unit comprising electrical control circuitry as shown in Figure 1 and a fluid flow system as shown in Figure 2. The fluid flow system comprises a flushing (hydraulic) system and a sterilizing system.

The electrical control circuitry consists of electronic circuitry, including switches, as shown in Figure 1. The electrical control circuitry controls the fluid flow system which can flush and sterilize up to three separate liquid dispensers and associated supply lines and other equipment of a liquid supply system. The fluid flow system supplies filtered water at a required pressure and at a required flow rate to flush liquid dispensers and associated supply lines. Where the liquid supply system is a real ale system such flushing would normally be carried out prior to changing a spent cask. In an outlet dispensing real ale the liquid dispensers would be hand pumps and the apparatus, or at least the electrical control circuitry, would be sited adjacent the hand pumps in a bar or other serving area.

Referring to Figure 1 the electrical control circuitry comprises a power supply unit (P.S.U.) 10, a switch/relay circuit 4, a first timer circuit 11 and a second timer circuit 12.

The power supply unit 10 operates to transform and rectify a 240 volts alternating current mains electricity supply to 12 volts direct current and to isolate the remainder of the circuitry from the mains supply for safety.

The first regulator 1 provides a variable d.c. supply preset to supply the correct operating voltage to solenoid valves, referred to below, in the flushing system and in the cleaning system.

The second regulator 2 provides a 12 volts d.c. supply to operate the timer circuits 11 and 12.

The switch/relay circuit 4 provides individual indication and outputs to three pairs of water solenoid valves 32 and 33. The circuit is such that only one output, to a selected pair of the solenoid valves, is available at any one time.

The first timer circuit 11 is a solid state variable timer circuit and governs the period that power is available to the switch relay circuit 4.

The second timer circuit 12 is also a solid state variable timer circuit and governs the period that power is available to two solenoid valves 24 and 29 controlling water flow to the cleaning system.

The fluid flow system comprises an inlet conduit 20 connected to a mains cold water supply so that water under mains pressure is supplied to the system.

The conduit 20 is provided with a 15 mm stopcock valve (SC1) 21 to turn the mains water supply on and off, a water authority approved non-return valve (NR1) 22, a deionizer/filter 23 and the solenoid valve (SV4) 24. The deionizer/filter 23 serves to reduce mineral and other chemical deposits on internal surfaces of flow control and solenoid valves.

The conduit 20 is connected to a conduit 26 of the flushing system and a conduit 27 of the cleaning system.

The conduit 26 is provided with a solenoid valve (SVSB) 26 and the conduit 27 is provided with a solenoid valve (SV5A) 29.

The solenoid valves 24, 28 and 29 control the rate of flow of water through the conduit 22 to the conduits 26 and 27 and control whether the water flows to the flushing system or the cleaning system.

The flushing system comprises three flow control sub-assemblies (FCSA).

Each such sub-assembly comprises a conduit 30 provided with a flow control valve (e.g.FC2) 31, a respective pair of the series-arranged solenoid valves (e.g. SV1, SV1A) 32, 33 controlled by a respective switch (S1, S2 or S3) 38 and the timer 11 (see Fig. 1) and a first non-return valve (e.g. NR3) 34.

Each sub-assembly also comprises, associated with the conduit 40, a second non-return valve (NR3A) 35.

Each conduit 30 branches from the conduit 26 and each is connected to a respective liquid supply line or conduit 40 i.e. a beer line. Each conduit connects a respective bulk liquid container, e.g. a beer cask, to a respective dispenser (i.e. a handpump).

The stopcock valve 21, the non-return valve 22, the deionizer/filter 23 and solenoid valves 24, 28 and 29 are sited in close proximity to the bulk liquid containers e.g. casks connected to conduits 40.

Each flow control valve 31 is adjusted to limit water flow. For real ale systems the valve is adjusted to provide a flow rater of 3.4 litres/minute. This flow rate may be adjusted to accommodate requirements of other systems.

The solenoid valves 31, 32 are controlled by a respective switch 38 and the timer 11 (see Figure 1).

Each non-return valve 34 is situated as close as possible to the respective liquid supply line 30 and it serves to prevent mixing of dispensed liquid and water in the portion of the conduit 30 between the valve 34 and the valve 33.

The non-return valve 35 serves to prevent flow of water along the conduit 40 back into the liquid storage container.

Each FCSA is used for a respective dispensing outlet (hand pump). The FCSA's are operated by the single control unit having the circuitry shown in Figure 1.

Each FCSA is preferably sited as close as possible to its respective bulk container (e.g. cask of real ale) and is adjusted, in conjunction with the timer 11, to supply a predetermined volume of water at a predetermined flow rate.

In real ale systems utilizing casks with a siphon system the non-return valve 35 is not required as the cask containers have an integral stop valve incorporated.

The sterilizing system comprises valves and flow control and pressure regulation means to enable carbon-dioxide assisted injection of sterilizing fluid to cleanse liquid dispensers conduits and associated equipment of a real ale dispensing system.

The sterilizing system comprises the conduit 27, the solenoid valve 29, a flow control valve (FC8) 50, a non-return valve (NR2) 51, a conduit 52 connected to the conduit 27, a non-return valve (NRG) 53 in the conduit 52, a cleaning bottle (CB1) 53, a float valve (FV1) 54, an industry standard cask head connector 55, a gas control valve (GCV) 56, a standard CO2 cylinder (C1) 57 and connector outlets (CC1, CC2, CC3) 58, 59, 60 for connection to beer lines and handpumps.

The flow control valve 50 is adjusted to limit water flow to 3.4 litres per minute in the case of a real ale system.

The float valve 54 prevents CO2 entering the system (specifically the conduits 52 and 27) when the cleaning bottle 53 is empty of sterilizing fluid.

The apparatus is operated as follows in accordance with the method of the invention.

The stopcock 21 is normally left open.

The liquid supply line 40 is flushed prior to changing a spent cask. When the cask is empty (and the stopcock 21 is open) an operator initiates the flushing process by pressing a system actuation switch (S4) 70 and selecting the control switch (S1, S2 or S3) 38 corresponding to the spent cask.

Closing the switch 70 energises the solenoid valves 24 and 28 making water at mains pressure available to the conduit 26 of the flushing system. The closure of the control switch S1, S2 or S3 energizes the respective solenoid valve pair 32 or 33 (SV1 and SV1A, SV2 and SV2A or SV3 and SV3A) allowing water at mains pressure to pass into the beer line 40 and through the dispensing handpump at a rate governed by the flow control valve 31 for a period of time determined by the timer 11.

The empty cask is replaced at any time during and after the flushing of the line 40.

After the flushing and after the replacement of the cask the control switch 38, is turned off and remaining water in the line 40 is drawn through the handpump until beer is seen to follow. After approximately 0.5 litres of beer has been drawn, the fresh beer from the cask is ready for serving.

Sterilizing of the beer supply lines is carried out as follows.

The line 40 to be cleaned is disconnected from the cask and fitted to one of the cleaning connectors 58, 59 or 60. The cleaning bottle 53 is filled with liquid sterilizing fluid and connected to the system by mans of the head 55.

The gas control valve switch 53 is then operated allowing carbon dioxide gas at 4 p.s.i. to enter the cleaning bottle 53. The sterilizing fluid is then forced into the beer line 40 via the cleaning connector.

When all old beer has been flushed from the system and sterilizing fluid reaches the handpump the gas control valve 56 is turned off to stop the flow of the sterilizing fluid. The cleaning bottle may be disconnected and stored for future use.

After a recommended time (normally 20 minutes) the operator activates a keyswitch (KS1) 80. This causes water to be flushed through the system via the solenoid valves 24 and 29 and the flow control valve 50 at a preset rate and in a predetermined amount. The timer 12 controls the time of this procedure and the volume of water used.

Upon completion of flushing the sterilized line is re-connected to the cask and remaining water is drawn through the handpump until beer is seen to follow.

After approximately 0.5 litres of beer has been drawn, the beer from the cask is ready to be served.

Claims (8)

1. Apparatus for flushing and/or sterilizing a conduit for conveying a liquid which apparatus comprises: a conduit system for connection to such a conduit and adapted to be connected to a supply of water at pressure, a container for containing a sterilizing fluid, and means for pressurizing sterilizing fluid in the container to deliver the fluid to said conduit system, the conduit system including:: control means to allow or stop flow of water, to control the rate of flow of the water, the flow path of the water and the duration of the flow of the water and to allow or stop the flow of the sterilizing fluid, the rate of flow of the sterilizing fluid and the duration of flow of the sterilizing fluid; and electrical means for selectively controlling the operation of the control means, such that, in use, water is caused to flow through said conduit, for a predetermined period of time and/or that sterilizing fluid from the container is supplied under pressure into said conduit and the sterilizing fluid allowed to remain in the said conduit for a predetermined period, the sterilizing fluid thereafter being flushed from the said conduit by means of water.

2. Apparatus according to Claim 1, wherein the conduit system comprises a first conduit for connection to the supply of water under pressure, a second conduit connected to the first conduit and for connection to the conduit firstmentioned in claim 1 for flushing said latter conduit and a third conduit connected to the first conduit and to which the sterilizing fluid can be supplied, means for connecting the second conduit to said conduit firstmentioned in claim 1, means for preventing backflow of liquid from said latter conduit through the second conduit and means for preventing backflow of the sterilizing fluid from the third conduit to the first and second conduits.

3. Apparatus according to claim 1 or 2, wherein said pressure is mains water pressure.

4. A method of flushing and/or sterilizing a conduit for conveying a liquid, which method comprises passing water through said conduit for a predetermined period of time; and/or injecting a sterilizing fluid under pressure into said conduit, allowing the cleaning fluid to remain in the said conduit for a predetermined period of time and thereafter flushing said sterilizing fluid from said conduit by means of water.

5. A method according to claim 4, wherein said water is mains water supplied at mains pressure.

6. A method according to claim 4 or 5, wherein said conduit is used for conveying real ale.

7. Apparatus for flushing and/or sterilizing a conduit conveying a liquid, substantially as described herein with reference to and as illustrated in the accompanying drawings.

8. A method of flushing and/or sterilizing a conduit for conveying a liquid, substantially as described herein with reference to the accompanying drawings.