GB758831A - Improvements in and relating to apparatus for combining fluid streams from separate sources - Google Patents

Abstract

758,831. Mixing fluids in flow. BOULY, H. G. (Thompson Products, Inc.). Sept. 15, 1953, No. 25469/53. Class 86. [Also in Group XXIX] Apparatus for combining separate fluid streams in equal or other fixed proportions comprises a substantially cubical block 11 having a number of independent inlet passages such as 24 and an additional pilot inlet passage 20 all communicating with a common outlet passage 28, the flow in each of the independent inlet passages being controlled by a valve 38 operated by pressure sensitive means such as the diaphragm 43, responsive to the pressure on the outlet side of the respective valve 38 and to the pressure of fluid in the pilot inlet passage at a point between a flow-metering valve 50 and the common outlet passage 28. The passages 20, 24 &c. open into the end face 12 of the block 11 to which is attached a header block 13 having corresponding inlet ports such as 15, 17. As shown, the block has three inlet passages such as 24 and a pilot passage 20. The three inlet passages open into valve bores 41 containing spaced valve guide rings or seats 39, 40 for the valves 38 which are similar and in the form of pistons with a central bore 79 and lateral grooves 42, the latter being adapted to provide communication between the inlet passages and shallow chambers 49 on the outer faces of the block. The chambers 49 communicate through externally-threaded orifice members 31 with the outlet passage 28. A similar orifice member is provided between the outlet 28 and a pilot chamber 51 communicating with the outlet side of the metering valve 50. The chambers 49 are closed by the diaphragms 43 which are clamped to the block 11 by dome-shaped plates 44 forming with the diaphragms 43 control pressure chambers 48 all communicating with the pilot chambers 51 through passages 80, 81. For equal flows, the four orifice members 31 have orifices of equal cross-section and for proportionate flows, the sizes of the orifices are varied accordingly. The pilot valve 50 is located in a threaded bore 55 between the passage 20 and the pilot chamber 51 and comprises a spring- loaded valve 57 having a central passage with a calibrated restriction 61 to accommodate small flows. For larger flows, a shoulder 67 on the valve moves away from a shoulder 68 on a valve guide member 63 exposing ports 65 which permit a larger flow to by-pass the restriction 61. The maximum flow is however governed by the size of the orifice connecting the pilot chamber 51 to the outlet passage 28. Specifications 758,908 and 758,909 (both Group XXIX] are referred to.