Patent GB-366915-A (GB)
Title: Improvements in apparatus for effecting the base exchange water softening process automatically
IPC: C02F1/42
Filed: 1930-10-31
Abstract: 366,915. Controlling flow of liquid ; softening water. DOUGLAS, J., 31, Bishop's Mansions, Bishop's Park, London. Oct. 31, 1930, No. 32758. [Class 46.] In a device particularly applicable to base-exchange water softening apparatus but stated to have a more general application, a flow of liquid is controlled by a meter acting through electrical means which, after stopping the main flow, initiate a flow of a further liquid through the apparatus (in the case of water-softening apparatus, a regenerating liquid) and finally re-establish the main flow. Apparatus shown in Fig. 1 comprises a tank 1 containing baseexchange material, a tank 17 containing regenerating solution, and a meter 20 connected to the hard water supply pipe 23 and adapted to close contacts in the circuit 26, 27 of an electric motor 28. The motor operates valves 4, 7 which control the flow through the tank 1 of water under treatment, of regenerating solution and of wash water. The valves 4, 7, as shown, are of the rotary plug type but valves of the reciprocating bucket type may be used. In operation water from the pipe 23 passes through the meter 20 and the inlet 15 to the valve 7, leaves by the outlet 6 and passes to the inlet 5 of the tank 1. The softened water leaves the tank 1 by the outlet 2, passes to the inlet 3 of the valve 4, and thence through the outlet 11 to the soft water main 12. When an amount of water corresponding to the softening capacity of the material in the tank 1 has passed, a dial arm on the meter 20 makes contacts to close the circuit 26, 27 and start the motor 28. The motor rotates the valves by means of a pinion 10 gearing with wheels 8, 9 on the valve spindles. The gear wheel 9 controls a master switch 42 which ensures that, when started, the motor will operate until the pinion 10 has completed one revolution corresponding to a third of a revolution of each of the wheels 8, 9. In the new position of the valves, regenerating solution passes from the tank 17 to the inlet 16 of the valve 7 and is led from the outlet 6 to the tank 1. After passing through the tank 1 the solution is directed by the valve 4 to an outlet 13 and waste pipe 14. When the level in the tank 17 has fallen by a predetermined amount a contact having connections with the switch 42 is made to set the motor 28 in operation and move the valves 4, 7 through a further step to a position in which hard water to wash out the regenerating solution is passed from the main 23 through the tank 1 and thence through the outlet 13 of the valve 4 to waste. In the meantime the dial arm of the meter 20 has been reset by a rack- and-pinion device, operated by a cam on the wheel 8 and a Bowden wire 65, to a position from which it travels to start the motor 28 after the passage of a desired amount of wash water. The motor then moves the valves 4, 7 to their original position, the dial arm of the meter 20 being at the same time reset to pass the predetermined amount of water for treatment. Figs. 7 and 8 illustrate the arrangement for resetting the dial arm of the meter. An arm 52 which engages the dial arm is carried at one end of a spindle 51 mounted in a frame 45. The Bowden wire 65 is connected to a frame 46 sliding in the frame 45 and carrying a rack which engages a pinion on the spindle 51. A complete resetting movement is limited by the contact of an arm 54 on the spindle 51 with an adjustable stop 55, but between two such movements there may be a shorter resetting movement, prior to measurement of wash water, limited by a stop 58, which is withdrawn when the longer movement is to take place by movement of the rack or by a second Bowden wire operated by a cam on the spindle of the plug cock. A spring 62 returns the frame 46 to its initial position. Fig. 20 shows diagrammatically an arrangement having two treatment tanks 80, 81 with connections such that water is being treated in one while the base-exchange material in the other is being regenerated. Valves 82, 83 make onesixth of a revolution and valves 102, 100 make one-third of a revolution for each revolution of the pinion 10. Valve 82 has a connection 84 to the hard water main 113 through a meter 110, connections 86, 87 to the tanks 80, 81 and a connection 92 to the outlet 106 of the valve 102. Valve 83 has a connection 98 to a soft main 130, connections 96, 97 to the tanks 80, 81, and a connection 99 to the valve 100. The valve 102 controls the passage of regenerating solution from a tank 119 and of wash water from the main 113 through a separate wash water meter 112 to the connection 92 and thence through the tanks 80, 81. The valve 100 controls the passage of waste water or solution from the connection 99 to a waste pipe 131. Modifications in detail which are described include (1) an arrangement in which the dial arm of the meter 20 releases a pawl from engagement with a ratchet quadrant and thus allows a mercury switch to close the circuit 26, 27, (2) the use of a meter measuring the flow of the regenerative solution for effecting the change of connections after regeneration, (3) the use of a pump for passing the regenerative solution through the base-exchange material. An arrangement is also described in which the regenerating solution is stored as a concentrated solution in one tank but drawn off for use from a smaller tank in which it is diluted. The pipe connecting the two tanks is provided with a spring-loaded valve and with a valve operated by a float in the smaller tank. Connections with float-operated valves supply make-up water to the tanks, and the spring- loaded valve between the tanks is opened only when the float valves controlling the make-up supply are closed. The Provisional Specification describes an arrangement in which a toothed rack is moved by gear associated with the meter to a position in which it releases a pawl and allows a mercury switch to close the motor circuit. The rack is reset by a spring- loaded arm to its initial or to an intermediate position.