GB1376150A - Cleaning method - Google Patents

Abstract

1376150 Cleaning/disinfecting pipework installations DE DANSKE MEJERIERS MASKINFABRIK AmsA 21 Dec 1971 [23 Dec 1970] 59378/71 Heading F2N Plant arranged in a fluid-conveying circuit, e.g. dairy installations for treating/conveying milk, is cleaned by circulating a flushing fluid through the circuit and adding to this fluid a cleaning concentrate for a period of time at least sufficient for all the fluid in the circuit to pass a certain point of the circuit, so that the ratio of fluid to concentrate tends to become constant throughout the circuit. The apparatus shown is for supplying fluid to and receiving exhausted fluid from a selected one of three circuits I, II or III (not shown). As shown, selection valves f connect circuit III between supply line e 1 and return line 15. Water is supplied to a tank 1, under the control of either one of level devices 2 and 3, and from thence via lines 5 and 6, pump 7, line 9, heat exchanger e, line e 1 circuit III, return pump 16, lines e 2 and 8 and valve a to a drain. After a certain time of cold flushing, steam is introduced via valve g to the heat exchanger to heat the flushing fluid in line e 1 . Valve g is controlled by a thermostat 19. Valve a is operated to recirculate the fluid rather than pass it to a drain. Cleaning concentrate is introduced from apparatus 10. When the flushing fluid containing cleaning concentrate has been circulated for a certain time, valve a is re-connected to drain to exhaust the cleaning concentrate after which disinfecting concentrate is introduced from apparatus 11 for a suitable time. The disinfecting fluid may either be recirculated or passed to the drain. Finally, the supply of steam to heat exchanger e is cut off and the system is cold flushed. If the circuit to be cleaned includes a tank, then tank 1 may be by-passed during the recirculating cycles. If the circuit includes only pipework, return pump 16 need not be operated. The concentrateintroducing apparatus 10, 11 may include a reciprocating pump, Fig. 2 (not shown), worked by compressed air fed to the pump in pulses via a valve controlled by an impulse generator, e.g. an astable multivibrator, Fig. 5 (not shown).