Patent GB-912474-A (GB)
Title: Apparatus for cleaning milk pipe lines
Filed: 1961-03-07
Abstract: 912,474. Washing apparatus for milk pipe lines. DE LAVAL SEPARATOR CO. March 7, 1961 [March 9, 1960], No. 8262/61. Class 99(2). Apparatus for cleaning a milk pipe-line comprises a chamber 22, a supply line 35, 43 for delivering liquid to the chamber and having valves 36, 44, conduits 66, 63 leading from the lower portion of the chamber to one end of the milk pipe line 5, a circulating pump 13 having its inlet connected via pipe 12 to the other end of pipe line 5 and adapted to be fed with liquid sucked from the chamber through the conduits 66, 63 and pipe line 5, and a diversion valve 68 connected to the pump outlet and operable in a first position to direct liquid from the pump to the chamber and in a second position to direct liquid to waste via drain 24. Tepid water supplied from hot and cold water pipes 31, 32 to the chamber 22 via pipe 35 is controlled by a valve 36 actuated by a solenoid S 4, a drain hole 25 in the chamber being closed by a valve 27, actuated by a solenoid S3. The level of water rises in the chamber and a float 47, slidable on a rod 45, abuts against an upper stop 49 on the rod which causes switch arm 46 to engage its upper contact U, thereby energizing solenoid S4 to cut off the supply of water and energizing a solenoid S to start a vacuum pump 9 which draws .water through the pipe-line 5 into a receiver 7. Because the circulating pump 13 is not yet operating, the water level rises in receiver 7 until a float 53 closes a switch 56-57 which energizes a solenoid S1 that starts the circulating pump 13 thus drawing water from receiver 7 and discharging it to drain receptacle 23 by way of diversion valve 68 whose solenoid S6 is de-energized. The level falls in receiver 7 until the float 53 opens the switch 56-57, previously locked in the closed position by a spring biased lever 59, thus stopping the pump 13. Substantially all the water is drawn from chamber 22 and passes continuously to receiver 7 and intermittently through pump 13 to drain. The falling tank float 47 eventually causes switch arm 46 to re-engage its lower contact L, thereby de-energizing solenoid S3 to open drain valve 27 and starting a first timer which continuously energizes the solenoid S1 for a pre-determined drying period, during which pump 9 and 13 effect a flow of air through the previously rinsed conduits and pipe lines. At the end of the drying period this timer de-energizes solenoids S and S1 stopping both pumps. The pipe line is now washed, this operation being initiated by the first timer on completion of the drying period. The operations are similar to those described except the hot water solenoid S5 is energized to fill the chamber 22 with hot water and detergent solution from chamber 39 and is then de-energized to the upward shifting of switch arm 46, which in this case starts vacuum pump 9 but also energizes the diversion valve solenoid S6 under control of a second timer, in this way, detergent solution is passed through the previously dried conduits and pipe-line and is re-cycled over a substantial period until the second timer de-energizes solenoid S6, whereby the diversion valve 68 discharges to drain receptacle 23, and the operations of unloading chamber 22 and drying proceed as before. After repeating the rinsing and drying operations the apparatus shuts down. A construction of an intermittently operated circulating pump and a circuit for controlling the apparatus is described. U.S.A. Specification 2,794,420 is referred to.