GB240938A - Improvements in or relating to central heating apparatus - Google Patents

Abstract

240,938. Moreau, H. July 15, 1924. Heating buildings. - Relates to hot-water heating-mechanism for buildings &c. of the type, such as is described in Specification 209,251, in which an intermittent flow of water through the radiators 21, Fig. 3, of the system is obtained by the use of a pulsator tank, in which an intermittent pressure is obtained and which may form part of a boiler 1, and an expansion tank 3, from which the return of water is controlled by a float 31 arranged either in the expansion tank or the. pulsator tank. According to the invention steam or other vapour is employed as the driving fluid and. the thrust is increased by effecting in some portion of the system a condensation of the driving fluid, thus producing a partial vacuum, while the valve 25, shown diagrammatically in Fig. 3, which controls the release of pressure from the expansion tank 3 or pulsator tank, is rendered fluid-tight during each pulsation by being flooded. In the arrangement shown in Fig. 3, the pulsating tank is formed in one with the boiler 1, and water is returned from the expansion tank 3 through a pipe 4 fitted with a non-return valve 22 and at its extremity with a perforated tube 24. After a discharge of water from the expansion tank 3 to the boiler 1, the float 31 sinks and by engaging a stop 30 on the valve spindle 28 opens the exhaust valve 25. Thereupon, as steam is generated in the boiler 1, the resulting pressure causes the valve 22 to close and a volume of hot-water to be driven through the system, the expansion tank again becoming filled and the float 31, by engaging a second stop 29, finally closing the valve 25. Subsequently, the pressure in the tank 3 increases to establish an equilibrium of pressure and prevent further circulation of water in the system. In order to open the valve 22 and allow the water to be returned once again to the boiler, a reduction of pressures in the latter is produced by effecting a condensation of the steam either by means of radiator 32 cooled by a fan 33 or by means of a pump delivering a spray of cold water, the fan 33 or the pump being controlled electrically by the displacement of mercury in a manometer 34 mounted on the tank 3. In addition, a valve 36, Fig. 4, connected to a float 38 in the boiler 1 may control a passage 35 communicating between the boiler and upper part of the tank 3, the valve 36 being closed so long as a substantial difference' in pressure exists between the boiler and tank, but opening when the pressures become nearly equalized. In a modified system, Fig. 5, the boiler 1 and pulsating tank 2 are separate, and the temperature, of the circulating water is maintained by a reheater 55 and/or an injector 58 delivering steam into the circulating water. The intermittent supply of steam for circulating the water is controlled by a valve 44 mounted on a pivoted lever 45 operated by movements of the valve spindle 48. A partial and intermittent condensation of steam in the upper part of the tank is obtained by the cooled water from the radiators 21 circulating in a coil 39<a> in the expansion tank. In a further modification, the driving fluid is the vapour of a liquid which boils at the temperature of the circulating-water and is vaporized by the latter, a condensation of the vapour being effected in the expansion tank by a coil such as 39a. In all of the constructions, the valve 25 regulating the exhaust is controlled by the float 31 and is main. tained flooding during each pulsation by an arrangement such as is illustrated in Fig. 6, where it is controlled by the same system of links as the valve 44. When the expansion tank 3 empties, the pulsating tank 2 and the well 63 are filled with water. During the forcing stage, as the tank 2 is emptied, the pressure of the driving fluid maintains the valve 25 closed; at the end of the pulsation the float 31 opens the valve 25, and the pressure existing in the tanb- 2 expels the water from the well 63 and pipe 64, the valve 44 being closed.