GB984307A - Deaerating apparatus for liquids - Google Patents

Abstract

984,307. Deaerating liquids; hot water systems. A. M. CASTLE & CO. May 11, 1962, No. 18202/62. Heading B1M. A deaerator for removing dissolved gases from liquids, e.g. the water of a circulating hot water system, comprises an upper tank 13 and a lower tank 14 which are alternately put under vacuum while the liquid flows from one to the other, whereby the dissolved gases are released from the liquid. The deaerator shown is connected to line 2 which returns water to the heater of the hot water system. Water is diverted from line 2 through pipe 3 and check valve 5, and is admixed with make-up water supplied via line 7 and valve 8. The stream of water passes through reducing-valve 6 and enters tank 13 via a throttling tube 9 and inlet 10. The bottom of tank 13 is connected to tank 14 via drain conduit 16 and diaphragm valve 18. Deaeration of the water takes place in tank 13 because the tank is under vacuum, and the gases evolved are forced out of the tank via inverted check valve 25, line 22, and check valve 23, by the rising water level in the tank. The water level continues to rise in tank 13 until the water covers electrode 47 when an electrical circuit is energized, causing pump 32 to start up and to commence drawing deaerated water from tank 14. The increased pressure of the water at the pump outlet 23 is communicated to the diaphragm of valve 18 via line 19, and causes this valve to close, thereby closing conduit 16. The deaerated water from tank 14 is pumped via line 35 and a three-way diaphragm-valve 37, back into tank 13 and fills this tank completely, thus displacing all the evolved gases from this tank, until the water closes valve 25. The pressure of water then builds up in tank 13 and on the diaphragm of valve 37 until the pressure is sufficient to cause valve 37 to reverse its direction, thus diverting the flow of deaerated water from pump 32 through check valve 40 and conduit 39 back into the heating water line 1 of the hot water system. The withdrawal of water from tank 14 by pump 32 creates a vacuum in this tank, causing any dissolved gases still present in the water to be evolved. Pump 32 continues pumping the water from tank 14 until the level of water in conduit 45 falls below a lower electrode 48, whereupon the pump stops and valve 18 opens. Water is now transferred from tank 13 to tank 14 via conduit 16, and a vacuum is created in tank 13 by the removal of the water. During this period of transfer of water, any gases evolved in tank 14 are displaced into tank 13 via conduit 45 and valve 46. When tank 14 is filled with water, tank 13 will contain a level of water several inches below electrode 47, and a vacuum will exist in the upper section of tank 13. The cycle of operation of the apparatus now repeats itself with a fresh supply of water entering from line 2.