GB2321588A - Water softener control for washing machine - Google Patents

Abstract

A programme controller sensitive to the machine operational cycle is electrically connected to a water softener control means (31) which controls the supply of softened water to the washing machine. The softener (13) is independant of the machine but is controlled by the machine programm to regenerate during the machine cycle for maximum efficiency.

Description

A Washing Machine Field This invention relates to washing machines, and in particular to ware-washing machines, which operate in co-operation with water softener devices.

Backqround of the Invention.

Ware-washing machines are typically used in commercial premises, such as restaurants, hospitals and canteens for the cleaning of dishes, glasses, cutlery, pots, pans, trays etc.

Typically these machines operate in co-operation with a water softener device so that the machine operates to maximum efficiency when the cleaning operation is performed. The water softener is conventionally an independent unit which is plumbed into the water supply to a washing machine to deliver softened water to the machine water inlet valve so that softened water is available on demand.

A water softener generally comprises a bed which is filled with a sodium ion exchange resin. Water passing through the bed is softened by an ion exchange in which the hard water ions, e.g. calcium and magnesium, are substituted by sodium ions. Eventually the softener becomes exhausted of its capacity for ion exchange and is no longer functional. The softener can then be regenerated by a reverse exchange which involves pumping salt (sodium chloride) water through the resin bed. This regeneration process is effected by valves on the softener, operated through a controller which is connected either to a manually operated on/off switch or more typically a timer operated programmer. In the case of a timer this is typically set to operate overnight.

Problems can occur due to the above arrangement. For example a machine operator may simply forget to switch on the regeneration system so that soft water is not available when required. If the regeneration is controlled by a timer and the machine is in frequent use, then again the softener may become exhausted before the next scheduled regeneration. On the other hand if the machine is erratically used and therefore idle for some time the regeneration operation may be performed when it is not necessary.

The present invention seeks to overcome the above problems.

Statements of Invention According to the present invention there is provided a washing machine having a programme controller which senses the machine operation cycle and is electrically connectable to a water softener control means which controls the supply of softened water to the washing machine.

The softener is caused to operate only when the washing machine is in operation, therefore preventing unnecessary regeneration cycles from taking place.

Preferably, the programme controller causes the water softener to begin regeneration as the washing machine enters its initial water heating phase. A high speed regeneration cycle generally takes about 25 minutes which is less that the heating cycle for the machine.

The programme controller may be the machine main programme controller or may be a separate controller connected into the main programme controller. Preferably the mains power supply to the water softener is via the washing machine so that switching on the machine automatically switches on the softener.

Also according to the invention there is provided a method of controlling the regeneration cycle of a soft water supply for a washing machine, in which method the control means of a water softener is connected to a programme controller on the washing machine which is sensitive to the machine cycle so that regeneration takes place during the machine cycle, preferably during the water heating portion of the cycle.

The above invention is applicable to all types of washing machine which operate in co-operation with a water softener but is particularly suitable for ware-washing machines.

Description of Drawings The invention will now be described by way of example and with reference to the accompanying drawings in which: Figure 1 is a schematic drawing showing the washing machine and its water supply system, and Figure 2 is a schematic drawing showing the control system.

Detailed description of the Invention With reference to Figure 1 there is shown a washing machine 11 typically a ware-washing machine, for example a WASHTEX 60 (trademark) dishwashing machine supplied by Electrolux Ltd.

The washing machine water inlet port 12 is connected to a water softener 13 through a conduit 14, valve 15 and connection 16.

The softener 13 is a high speed regeneration softener, for example a DR10 available from Ferex Ltd. The softener has four conduits 21-23, a supply conduit 21 connected to the machine 11 through the connection 16 and valve 15, a mains water inlet conduit 22, a salt solution supply conduit 23 for the regeneration of the softener 13, and a waste conduit 24.

The four inlet conduits 21-24 are opened and closed by respective valves 25-28, which form part of a multi-port valve. The valves 25-28 are operated by a cam shaft, slider, or piston 29 driven by a motor 31 operated by a control 32.

The mains water supply conduit 22 is connected to a water supply conduit 34 on the machine 11 via a connection 35, and valve 36. The conduit 34 is connected to a water supply 30 through a pump 39 which maintains the water supply to the softener 13 at a minimum pressure, preferably about 2 bar.

The supply conduit 34 is also connected through the multi-port valve unit 25-28 to a salt container 37 for the supply of salt solution to the softener for regeneration. This connection is represented by the conduit 38. The salt container 37 may be integral with the softener 13 to which it is connected internally, represented as conduit 23, or arranged remotely of the softener and connected through a conduit 23. The cam shaft or slider 29 operates so that when valves 21 and 22 are open to supply soft water to the machine 11, valves 23 and 24 are closed, and when regeneration takes place the valves 21 and 22 are closed with the valves 23 and 24 open, allowing salt water to pass from the container 37 through the softener to waste.

The pump 39 preferably maintains a pressure of 2 bar for satisfactory regeneration. The conduit 34 is connected to the conduit 14 through a valve 40 allowing the machine to be operated without a softener 13 by closing valves 15 and 36 and opening the valve 40. This allows the option of fitting a softener or leaving the softener out in soft water areas, or removal of the softener for repairs.

Now with reference to Fig 2., the machine 11 has a main programmer 50 which controls the operational cycle of the machine. An electrical cable 51 connects the machine 11 to the softener 13 via a plug and socket connector 52. The electrical cable 51 connects with the softener control means 32 for the supply of electrical power to the softener 13 and for the supply of control signals for operation of the multiport valve motor 31.

The cable 51 is a three wire cable comprising permanent live and permanent neutral wires connected into the machine electrical power circuit, and a control live wire connected to the machine programmer 50 so that the control live wire passes a signal to the softener control means 32 when the machine is at a particular phase in its operational cycle. The cable 51 could also include an earth wire. When the ware-washer is started up it first fills its water reservoir tanks with water from the softener 13. At this point the machine enters the tank heating phase to bring the water up to the required temperature. The control live wire is connected to the programmer 50 so that it passes a start signal to the softener control means 32 as soon as the heat-up starts, causing the softener to begin regeneration as previously described. The cycle takes about 25 minutes which is ideally shorter than the heating period. At the end of the heating period the multiport valve slider 29 will open the valves 21,22 and close the valves 23,24 and the softener 13 will thereafter supply softened water until the next start up sequence or exhaustion of its capacity.

In an alternative arrangement, the softener could take its electrical power directly from an electrical mains and not from the machine 11. The control live wire could also be connected to a separate programme controller which senses the machine operation cycle.

Claims (14)

Claims

1. A washing machine having a programme controller sensitive to the machine operational cycle and which is electrically connectable to a water softener control means which controls the supply of softened water to the washing machine.

2. A washing machine as claimed in claim 1 wherein the programme controller causes the water softener to begin regeneration as the washing machine enters its initial water heating phase.

3. A washing machine as claimed in claim 2 wherein the programme controller is the machine main programm controller.

4. A washing machine as claimed in any one of claims 1 to 3 wherein the programme controller is connected to an electrical cable having a plug or socket at its end away from the controller for connection to a cooperating electrical plug or socket connected to the softener.

5. A washing machine as claimed in any one of claims 1 to 4 wherein the washing machine electrical power circuit is connectable to the water softener electrical power circuit so that electrical power to the softener is supplied via the machine.

6. A washing machine as claimed in claim 5 wherein the electrical cable is a three-wire cable comprising a permanent neutral, a permanent live, and a control live which can pass a control signal from the programme controller to the water softener control means.

7. A washing machine as claimed in any one of claims 1 to 6, where the machine includes a mains water supply conduit with outlet valve, a water inlet conduit with inlet valve, and a bypass valve between the two conduits.

8. A washing machine as claimed in claim 7 wherein the mains supply conduit passes through a pump which pumps pressurised water to the softener.

9. A washing machine substantially as described herein.

10. In a method of regenerating a soft water supply for a ware-washing machine, regeneration of the softener takes place as the machine initially heats up its cleaning water.

11. A method of controlling the regeneration cycle of a soft water supply for a washing machine, in which method the control means of a water softener is connected to a programme controller on the washing machine sensitive to the machine operational cycle so that regeneration takes place during the machine cycle.

12. A method as claimed in claim 11 wherein the programme controller causes the regeneration to begin with the initial heating up for the washing water.

13. A method as claimed in claim 12 wherein once the regeneration is complete soft water is available for the next machine start up.

14. A method as claimed in any one of claims 11 to 13 when applied to a ware-washing machine.