GB571564A - Improvements in high-pressure hot-water heating systems - Google Patents

Abstract

571,564. High-temperature water heating systems. BUCKLE, G. H., and DURBAN. H. F. S. Sept. 27, 1943, No. 15843. [Class 64 (ii)] In a high-temperature water heating system in which hot water from a boiler is circulated by a pump 11 through flow and return pipes 12, 13, the water in the system is treated for the removal of dissolved solids, and preferably also of gases, by abstracting it from the system, continuously or intermittently, and passing it through suitable treatment plant before return to the system. As shown, the treatment plant comprises essentially an evaporator 14 having a heating pipe 16 connected by branches 17, 18 respectively to the pipes 12, 13 and also a blowdown valve 15 for the separated solids, a makeup water tank 23 with a float-controlled inlet valve 24 and an outlet valve 25 with stop valve 26 leading to the evaparator, a condenser 29 including a coolant circuit 33, and a condensate receiver and gas-removal tank 32 having a heating pipe 35 connected to the said with water from the branch 18 through a pipe 19, stop valve 22 and automatic constant-level feed regulating valve 20, and the steam formed therein passes through a pipe 28 to the condenser 29 from which the condensate is led to the tank 32 through a vapour trap 30 and float-controlled valve 31, thence to the boiler 10 by a feed pump 37. The rate of flow through the heating pipe 16 is controlled by an automatic regulator 21 adapted to maintain a constant steam pressure in the evaporator ; the coolant circuit 33 is also provided with an automatic controlling valve 34, responsive to the temperature of the condensate in the condenser 29, and the heating pipe 35 with a similar valve 36 responsive to the condensate temperature in the tank 32. The arrangement is such that, with the valve 22 open and the valve 26 shut, circulation through the treatment plant will be continuous until the water level in the tank 32 rises to such an extent that the valve 31 shuts. The temperature of the condensate in the condenser 29 will then fall and cause the valve 34 to shut and, simultaneously, the rise in pressure in the evaporator 14 causes the valve 20 to interrupt the feed thereto and the regulator 21 to stop the supply of heat to the pipe 16. The pump 37, which is adapted to deliver slightly less water than the evaporator and condenser are capable of handling so that it should never run dry, thus controlling the rate of circulation of water through the treatment circuit. A float-actuated switch 38 may, however, be provided to stop the pump if the tank 32 becomes empty. In a modification the heating pipes 16, 35 are supplied with steam from the boiler 10. An alternative form of treatment plant, not shown, comprises an auxiliary steam generator adapted to operate at a pressure exceeding that in the boiler of the system, means for supplying the auxiliary generator with water bled from the system, a gas-separator chamber communicating with the steam spaces of both the boiler and the generator, and means responsive to the water-level in the boiler for controlling the flow of steam thereto from the generator.