GB567799A - Improvements in devices for mixing fluids - Google Patents

Abstract

567,799. Mixing fluids. McMEEKIN, J. S., and McNAMEE, J. J. March 11, 1943, No. 4014. [Class 64 (i)] A device for mixing two fluids, e.g. steam, or hot water, and cold water, comprises essentially a mixing chamber M, Fig. 1, in the form of narrowly spaced walls 21, 22 to which the steam and cold water are led from inlets 12, 13 and through a nozzle part 18 and annular passage 24 with discharge port 25 respectively, the flow of steam through the said nozzle 18 being controlled to regulate the temperature of the resultant hot water at the outlet 14 of the device by a guide 20 which coacts with the nozzle part 18 to form a valve and is actuable by a handle 15 and by an associated thermostat 28, 29 located in a casing 10 between the chamber M and its outlet 14. As shown, the nozzle 18 is of convergent form and is surrounded by the passage 24 and port 25, the arrangement being such that the steam from the nozzle will be spread into a thin sheet in the mixing chamber and the cold water entrained by and interspersed therewith, the resultant hot water passing through ports 26 at the periphery of the mixing chamber and through the casing 10 past the thermostat to the outlet 14. The thermostat comprises three superposed sets of radially-arranged bimetallic bent strips 28, 29 of M-form in section, each set consisting of four quadrantal pieces, Fig. 3, and each quadrant being separated from the next by a radial slot 31 and itself divided by two narrow radial slots 30. The uppermost strip 28 is secured to an axially-adjustable, non-rotatable nut 39, the lowermost strip 29 to the valve 20, and the intermediate strips to interlocking nut units 34, 35, the latter units and the guide or valve 20 being slidably mounted upon a rod 36 depending from a screw 37 which is rotatable by the handle 15, but locked against axial movement by a projection 38. In operation, rotation of the handle 15 and screw 37 will effect axial movement of the nut 39, strips 28, 29 and valve 20 towards or away from the nozzle 18 to regulate the flow of the, steam, this hand control being subsequently influenced by the thermostat if the temperature of the water in the casing 10 rises or falls relatively to the temperature for which the handle 15 is set. In a modification, Fig. 6, for use where the water supply is at atmospheric or a lower pressure, the water is led to an annular chamber 54 which is located on the side of the valve 51 opposite to the nozzle 50 and is provided with a nozzled outlet 55 having a rapidly flowing divergent outlet 57 and a seating surface 58 for co-operation with a surface 52 on the back of the valve 51, the outlet 57 forming a suction zone S and the surfaces 52, 58 constituting a valve for the water supply which opens or closes when the steam valve 50, 51 closes or opens respectively.