GB819572A - Improvements in or relating to electric water heaters - Google Patents

Abstract

819,572. Electric water heaters. PRICE, W. Jan. 16, 1956 [Jan. 20, 1955], No. 1719/55. Class 39(3) In an electric heater for the rapid heating of a flow of water, cold water passes from a supply pipe 12 via a needle control valve 13 to a switch 14 operated by water pressure, the water then passing through a pipe 15, the primary portion 49 of a heat exchanger 16 and through a pipe 17 to a lower heating chamber 18 connected at 19 to an upper heating chamber 20. The heated water then passes through a trap 22 into the secondary portion 48 of the heat exchanger when it flows through a pipe 21 to an outlet 23. The pressureoperated switch 14 comprises inlet and outlet ports 27, 28 which open into an annular recess forming a chamber 29 closed by a flexible diaphragm on which bears a disc-shaped head 36 of a plunger 35. A lever 40 pivoted at 38 and carrying an adjusting screw 41 has two arms 46 for engagement with the operating plungers of micro-switches 45 which control heating elements 50. The screw 41 bears on the plunger 35 and the lever is urged downwardly by a compression spring 43 adjustable for tension. When the water is turned on at the valve 15 the diaphragm and head 36 are displaced upwardly and water flows into the chamber 29. The restriction imposed by the outlet port 28 and pipe 15 results in a rise in pressure in the chamber and the plunger is caused to rise still further to positively close the contacts of the switches 45 and to energize the heating elements. An indicator lamp may be provided which lights when the switch contacts are closed. The heating chambers and heat-exchanger may be arranged vertically. According to the Provisional Specification the heating element is formed into a helix.