GB1262181A - Methods of and apparatus for controlling fluids - Google Patents

Abstract

1,262,181. Automatic pressure control. NORTH AMERICAN UTILITY CONSTRUCTION CORP. Feb.5, 1969, No.6278/69. Heading G3R. An electrical signal periodically responsive to variations of pressure in a fluid supply line relative to a predetermined pressure controls the number of jet inductors supplying fluid to the line to maintain the pressure constant. In Fig.4, if the pressure of fluid supplied from a manifold 84 is outside limits set by adjustable contacts 23, a coil 24 or 25, according to the sense of error, is energized intermittently through a switch 26 periodically operated by clockwork. As a result, a rotary switch 27 is operated in a corresponding sense to alter, through electromagnetic relays 30-33, the number and combination of valves 38-41 which are open to supply fluid from a header 100 to manifold 84, until the pressure is restored between the limits. A further fluid is introduced into manifold 84 by jet induction from a header 85. The supplies to headers 85, 100 are controlled by valves 90, 99 which are adjusted automatically and intermittently if the pressure in manifold 84 is outside limits determined by the setting of pressure-responsive switches 93, 96. If fluid is supplied to header 100 through a heat exchanger 104, the supply of fluid and heat to the heat exchanger may also be controlled by pressureresponsive switch 96 as shown. The frequency of operation of interrupter switches 26, 92, 97 may be varied according to the time of day.