Patent GB-573705-A (GB)
Title: Improvements in steam and water mixing devices
IPC: G05D23/13
Filed: 1943-11-03
Abstract: 573,705. Heating water. ADLAM, T. N. Nov. 3, 1943, No. 18209. [Classes 64 (i) and 64 (ii)] [Also in Group XXIX] In apparatus in which steam and water are mixed to provide a hot water supply in a casing 10 with steam and water inlets 12, 13 and a hot water outlet 18, and valves 16, 17 (not shown) regulate the supply of steam and water to the casing, the steam supply valve 16 has steam pressure actuated means for moving its valve element in one direction, and means are connected with the water supply on opposite sides of the water supply valve 17 so that the steam pressure actuated means are controlled by the pressure difference on opposite sides of the water supply valve in order to maintain the steam supply valve closed when the water supply valve is closed. Steam flows through a pipe 14, past a return valve 108, into a cylinder 116 with openings 119, and enters the water in the casing 10, Fig. 3, through narrow openings between annular plates 115, which are alternately radially corrugated and flat. The supply of steam to the pipe 14 is controlled by a valve 16, Fig. 7, in which the steam first enters a chamber 21 through a port (not shown) and, when the valve element 25 is lifted from its seating 24, passes into the chamber 22 with a port (also not shown) leading to the pipe 14. When another valve element 78 is lifted from its seating, steam can also pass from the chamber 21 through an opening 48 into a chamber 46 which communicates with a chamber 36 on the lower side of a diaphragm 31 through a pipe 43 containing a valve 20, Fig. 6, which is responsive to the pressure difference on the two sides of the valve which controls the supply of water to the chamber 11. If the valve element 78 and the valve 20 are both open, the steam which enters the chamber 36 lifts the diaphragm 31 and opens the valve element 25 against the springs 28, 37. If either the valve element 78 or the valve 20 is closed, steam is cut off from the chamber 36 and the valve 25 closes. Steam in the chamber 46 when the valve element 78 is closed can leak through the narrow passage 49 into the chamber 22 and then into the pipe 14. The valve element 78 is operated by a thermostatic element comprising a tube 88 containing an expansible fluid, a connecting tube 87, and a tube 85 containing a piston 81 pressure upon which due to the fluid is transmitted by a rod 82 to the valve element 78. The piston rod is enclosed by an expansible tube 86 which acts as a seal. The tube 88 contains an expansible tube 94 with a closed end 95 which can be moved up and down the tube 88 by the action of a screw 100 transmitted to a rod 96 by a spring 98. By this means the volume of the tube 88 occupied by the expansible fluid, and consequently the temperature at which the valve element 78 is opened and closed, can be adjusted. In the valve 20, pipes 70. 71 connect the inlet and outlet sides of the water supply valve to opposite sides of the diaphragm 64. When the water supply valve is open, the pressure on the inlet side is greater than on the outlet side, so that the diaphragm 64 is moved down against the spring 72. This allows the element 63 to move down and so open the passage 56 by which steam passes from one part of the pipe 43 to the other, and closes the passage 57. When the water supply valve is closed, the pressures on both sides of it are equal, and the spring 72 can lift the diaphragm and so move the element 63 to close the passage 56 and open the passage 57. Through the latter steam in the chamber 36 can pass into the pipe 14.