GB837263A - Apparatus for mixing liquids of different temperatures - Google Patents

Abstract

837,263. Mixing liquids. A'BECKETT, W. J. Aug. 5, 1958 [Aug. 21, 1957], No. 25009/58. Class 86 An apparatus for mixing liquids of different temperatures to provide a constant temperature effluent has a mixing chamber 4 with hot and cold inlet ports b, 7 respectively and an outlet port 10 (Fig. 1, not shown). A piston valve 11 with radial ports 12, 13 is constrained at its upper end by a flexible diaphragm 3. The radial ports 12, 13 are so arranged that when the valve is at the lower end of its travel hot water may pass from the inlet port 6 and its associated annular groove 8 through ports 12, 13 into the bore 14 of the piston valve 11; as the valve rises the ports 13 make register with the cold water inlet 7 and its associated groove 9. When the apparatus is connected to sources of fluid supply hot and cold water pass by ports 12, 13, the bore 14 and passages 27 to mixing chamber 4. Cold water also passes through passages 20, 21 to the chamber 5 above diaphragm 3 which is depressed by the fluid pressure depressing piston valve 11 admitting more hot water to mixing chamber 4. When the temperature therein rises above the desired limit the thermosensitive metallic spiral 24 operates control rod 25 opening ball valve 27 allowing fluid to pass from chamber 5 through passage 28 and slot 26 to chamber 4. releasing the pressure in chamber 5, when piston valve 11 will be urged upwards by spring 15 admitting less hot and more cold water. The passageway 21 is provided with a pressure relief valve 23 to ensure constant pressure in chamber 5. The temperature at which valve 27 opens may be adjusted by an adjusting screw 29 having a tapered nose bearing or control rod 25 and operated by an external knob 31 which may have a pointer and scale. Specification 775,064 is referred to.