Patent GB-494199-A (GB)
Title: Improvements relating to water softening apparatus
IPC: C02F1/42
Filed: 1937-08-27
Abstract: 494,199. Softening water. UNITED WATER SOFTENERS, Ltd. (Permutit Co.) Aug. 27, 1937, No. 23561. [Class 46] An automatic base-exchange water-softening plant is provided with automatic control of backwashing so that the number of backwashings for each regeneration, the quantity of water used or the duration of flow may be varied. A water-softening plant to which the automatic control is applied, is shown in Fig. 4. A zeolite bed in a container 1 is regenerated with brine from a measuring tank 2 to which the brine is supplied from a salt saturator 3. The flow of water and brine through the softener is controlled by a rotary valve 4. The crude water passes from a pipe 5 to a pipe 6 leading to the top of the container and the softened water flows out through the pipe 7 to the valve 4 and thence through a pipe 12 to a water meter 33 from which it passes to the point of use. The meter actuates a switch 107 starting a motor 60 that drives the valve 4 through reduction gearing, setting the valve for backwashing, the motor then being stopped by a circuit-breaking switch 108 opening a circuit causing a switch 36 to open and stop the motor. The crude water is then delivered from the valve 4 through the pipe 7 into the bottom of the container emerging at the top through the pipe 6 from which it passes through the valve 4 to a pipe 8 into a drain sump 26. A timing device 35 starts the motor again after the backwashing has been completed and so the valve 4 is moved into the brining position, the motor being stopped by the switch 108. The crude water from the pipe 5 is directed by the valve through a pipe 13 containing an ejector 14 into the container 1, brine being drawn up with it by the ejector from the tank 2 past a valve 24. The brine passes out through the pipe 7 to the valve 4 and thence through a pipe 9 into the sump 26. When the material has been sufficiently brined, a float switch 37 starts the motor to move the valve into a position in which the incoming water passes through the pipe 6, rinses the material in the container and escapes through the pipe 7, valve 4 and pipe 9. The timing device 35 controls the duration of rinsing, and when this is complete, the motor is again started to move the valve back to starting position. The circuit-breaking switch 108 is formed with contact strips 126 ... 131 and 309 corresponding to the several control positions taken by the valve 4. From these strips connection is made through a brush 122, sleeve 124 and contact spring 125 to the control supply line 132 on the one side and on the other through switches controlled by the timing device to a solenoid 102 back to the line 132, the solenoid 102 controlling the current to the valve motor 60. The timing switches are actuated by cams A, B, C, D, E, on a shaft 306 driven through a suitable gear train by a motor 305. By adjustment of the cams A, B, C, D, E on their shaft, the softener can be adjusted to omit backwashing or brining and rinsing for a desired number of cycles, for varying the duration of the backwashing or the rinsing, for giving backwashings of different durations in successive regenerations, to give extra backwashings between regenerations. Modifications are described in which by the provision of gearing between the valve shaft and the switch sleeve 124, an extra row of contacts on the switch and further timing device, washings can be omitted or rendered very short on one of a desired number of regenerations.