Patent GB-779522-A (GB)
Title: Improvements in or relating to electrical apparatus for controlling in a predetermined order the operation of a number of components
Inventor: MARCZYNSKI WLADYSLAW
IPC: H02P1/58
Filed: 1952-09-12
Abstract: 779,522. Switching systems. NECKAR WATER SOFTENER CO., Ltd., and SOUTH WALES SWITCHGEAR, Ltd. Oct. 21, 1953 [Sept. 12, 1952], No. 23024/52. Class 38 (4). [Also in Group XXXVII] A base exchange water softening installation comprises valves A-F, each having a control motor AM-FM. Each valve member 1 has a shaft 2 with a threaded part 5 and is driven through pinion 3 and worm wheel 4. The valve motors have reversing relays, such as relays ACL, AOP, with contacts ACL1, AOP1, in the supply leads of the motor in the case of the valve A. Energization of the relays is controlled by a uniselector switch with banks of contacts 7-14, and, under normal operating conditions, when crude water is passed through the installation for softening, valves B, D are opened the remainder being closed. Under these circumstances the wiper arms of the uniselector switch are in the home position. A control signal is applied to terminal 15 when the calculated quantity of water has passed through the installation so that the wiper arms of the uniselector move on to the second contact, in which position the regeneration process is initiated. The first part of the process is the back washing of the zeolite with crude water and, for this purpose, the valve B is closed by energizing the relay BCL. As the shaft of the valve B moves downwardly a bar 18 actuates a limit switch for stopping the motor with the valve in the closed position and a circuit is completed for stepping the wiper on to the third contact of the selector banks. The valve D is then closed and the uniselector is stepped into the fourth position in which the valve A is opened. In the fifth position, valve C is opened, the wiper arms remaining in the sixth position for a period determined by a timing relay TR1. At the end of this period, the relay sends an impulse to step the wiper arms of the uniselector from the sixth position in readiness for the regeneration of the zeolite by means of brine which is pumped under the control of relay PR. In passing from the seventh to the tenth position of the uniselector, the valves C and A are closed in turn, followed by the opening of the valve E and then the valve F. In the eleventh position, the relay PR is energized and the brine pump is started. When an appropriate quantity of brine has been pumped, a flow control device applies an impulse to lead 31 for moving the wiper to the twelfth position. The final operation is the washing out of the brine, and this is prepared for by closing valve F and then opening valve B in the twelfth and thirteenth positions respectively. The washing out operation is terminated by an impulse from a time delay relay TR2. To prepare the installation for the normal supply of water, the valve E is closed and the valve D opened in the fifteenth and sixteenth positions respectively, after which the uniselector is self-driven to the home position. Lamps A1-F1 indicate the positions of the valve stems, and the operation of the pump relay PR during regeneration is shown by an indicator lamp P1L. Each pair of indicating lamps such as GO1, RO1, and GO2, RO2, is associated with one part of the regeneration cycle. Lamps GO1-GO4 indicate correct operation and lamps RO1-RO4 faulty working. When the fault-indicating lamps are operated, an audible alarm is also given. Thus, if one of the valves fails to operate the wiper arms of the uniselector will rest in the appropriate position and a timing relay TR will energize a buzzer BU and one of the lamps RO1-RO4 showing in what part of the cycle the fault has occurred. The motor-operated valves may be replaced by pneumatic or hydraulically-operated valves having a solenoidactuated pilot valve.