Patent GB-531008-A (GB)
Title: Apparatus for regulating the flow of liquid
IPC: G01F1/20
Filed: 1939-07-08
Abstract: 531,008. Regulating fluid flow. EVANS, C. H. July 8, 1939, No. 19929. [Class 135] Apparatus for delivering a constant flow of liquid under a constant head maintained in relation to a delivery orifice is provided with means for varying the head of the liquid and simultaneously effecting a variation in the crosssectional area of the discharge orifice. In the form shown in Figs. 1 and 2, liquid entering at 8 passes through a control cock 10 and filter 12 housed in a lower block 4 to a flow indicator 13 and thence through a passage 21 in an upper block 5 to an adjustable valve seat for a floatcontrolled inlet valve. The flow indicator comprises a float 14 housed in a transparent tube 13 held in stuffing boxes 17, 18 in the blocks 4, 5. The passages in the blocks are closed by removable plugs 19, 20, the plug 20 having a depending pin to prevent the float passing out of sight while the lower plug has a pin with a cupped end to provide a support for the float in its lowest position. The adjustable seat slides in stuffing boxes 23, 24 in the upper block and is adjusted by a screwthreaded part 25 engaging a bridge 29. At an intermediate part it is reduced in diameter and provided with axial and radial passages to establish communication with an inlet passage 21. At its lower end the seat is provided with an orifice 30 adapted to co-operate with a needle valve 38 mounted on a float 1 reciprocally arranged in a transparent float chamber mounted in stuffing boxes in the blocks 4, 5. A second needle valve 39 longer than the needle 38 is carried by the lower part of the float and co-operates with an interchangeable discharge nozzle 34. This nozzle is mounted on a removable plug 32 having a discharge chamber 33 closed by a cover 36 secured to the discharge conduit 37. To maintain the same pressure in the discharge and float chambers the plug 32 is formed with radial passages 40 leading to an annular chamber 41 connected by passages 42, 44 in the blocks 4 and 5 with the float chamber at a point adjacent the inlet orifice. In a modification. the blocks are held together by a series of bolts, the adjustable seat being provided with an external supply conduit and adjusted by a rack and pinion fitted with a pointer co-operating with a scale. In this form a pipe in the float chamber provides the pressure equalizing conduit. In the form shown in Fig. 4, the adjustable seat is supported by a pair of diaphragms 77 clamped in recessed apertures in the upper block by screwed rings 78, 79, and the float is guided by two pressure equalizing pipes 98, 99. In this form the discharge chamber is fitted with two calibrated discharge nozzles 94, 95 to divide the outflow into proportional streams. The flow indicator in this form has a tapered tube. In a further modification, the float chamber is made telescopic and the seat is rigidly secured to the upper block which is adjusted by a rack and pinion. Where two or more flows are required to be maintained in proportion the apparatus may be duplicated and the seats provided with a common adjustment. The apparatus may be provided with a heating or cooling jacket. The float may be fitted with a magnet to couple it magnetically in kncwn manner with indicating, recording or switching gear for operating alarms and the like.