Patent GB-456460-A (GB)
Title: Improvements in fluid flow controller system
IPC: C02F3/04
Filed: 1935-06-20
Abstract: 456,460. Fluid - control systems. TRIGGS, W. W., 57, Lincoln's Inn Fields, London.-(General Zeolite Co. ; 333, West 25th Place, Chicago, U.S.A.) June 20, 1935, No. 17789. [Class 135] In a flow - control system for a number of fluid flows having a regulator in each flow including an element arranged to determine the rate of flow in accordance with a gas pressure applied thereto, devices are provided whereby a predetermined common gas - pressure can be applied to the elements, and separate devices are provided whereby, alternatively, independent gas pressures, which may be regulated to different predetermined values, may be applied to the elements. In the embodiment described, the flow of liquid in the pipe 2, Fig. 1, is regulated by a valve 5 actuated by pneumatic pressure in a cylinder 11 the operation of which is controlled by a valve 4 the stem of which is connected to a weighted diaphragm 50, Fig. 3. The diaphragm 50 is mounted in a casing together with other diaphragms 54, 61, 62, and pipes 6, 7 connect the bottom and top of the casing to the upstream side and throat of a Venturi tube in the pipe 2. A small orifice 52 is provided in the diaphragm 50 and a larger one 55 in the diaphragm 54, the latter co-operating with a fixed disc 56 to control the flow of liquid from the chamber 53 between the diaphragms 50, 54, to the chamber 66 above the diaphragm 54. A bell-crank lever 59 has one end connected to the diaphragm 54 by a forked link 58, and the other end connected by links 60 to the diaphragms 61, 62 so that movement of the diaphragms 61, 62 causes alteration of the distance between the opening 55 and the disc 56. Pressure air is supplied to the chamber 64 to load the diaphragm 62 from a pipe 18 connected through a reservoir pipe 23 and pressure regulator 24 to a header 26, a pressure gauge 29 and a bleed valve 28 being provided. When the liquid starts to flow in the pipe 2, the pressure in the chamber 66 drops and liquid flows through the hole 55. Pressure in the chamber 53 then drops as the hole 52 is much smaller than the opening 55, and when such drop is sufficient causes the dia. phragm 50 to rise and operate the valve 4 so that the flow control valve closes to diminish the flow until equilibrium is established. As the distance between the disc 56 and hole 55 controls the rate of flow between the chambers 53, 60, it controls the movement of the diaphragm 50 and thus determines the movement of the valve 5 and the rate of flow in the pipe 2. This distance is regulated by the pressure on the diaphragm 62 which is set by the regulator 24. The pressure gauge 29 may therefore be calibrated to read the flow directly. In order that the flow in a number of pipes 2 may be set from a single regulator 31, two-way cocks 20 are provided in each pipe 18 whereby alternative connection may be made to a header 36 controlled by the regulator 31. The flow may be further controlled according to the level of water in a reservoir or clearwell 40, Fig. 4, and for this purpose the chamber 63, Fig. 3, is connected by a pipe 38 to a vertical pipe 39, the lower end of which dips into the reservoir and the upper end of which is connected to the pipe 18. In operation, the bleed valve 28 is closed and a valve 42 in the vertical pipe adjusted so that if the lower end is exposed due to lack of liquid in the reservoir, normal leakage takes place along this pipe, instead of through the valve 28, and the flow controller works normally. As the liquid level rises, pressure builds up in the vertical pipe and therefore in the chamber 63 and so acts against the pressure in the chamber 64, finally causing the valve 5 to closo if the pressure is not relieved by liquid being drawn from the reservoir. The pressure in the chambers 63 of several units may be subject to one control similarly to that for the chambers 64.