GB700524A - Steam or hot water boiler, furnace or other apparatus having a combustion chamber under pressure in relation to the heat-absorbing parts of the apparatus - Google Patents

Abstract

700,524. Pressure-exchangers. AKTIEBOLAGET GUSTAVSBERGS FABRIKER. May 17, 1951, No. 11602/51. Class 8 (1). [Also in Group XIII] Relates to apparatus such as a boiler or furnace having a combustion chamber 7 under presure in relation to the heat-absorbing parts 10, e.g. water-filled walls of a boiler, and from which chamber the hot combustion gases are taken at high pressure by a pressure-exchanger comprising a rotor 1 rotating in a casing 2 having a high-pressure inlet 5 at which the hot gases enter to be conveyed to a low pressure stage and there be replaced in the cells of the rotor by an equal volume, at lower pressure, of Àcolder and therefore heavier gas entering by an inlet 3 to displace the hot gases into an outlet 4. Moreover, the cold gas is returned to the high-pressure stage and forced out of the cells by further hot gas from the inlet 5 so that the whole exchange results in the transfer of a larger weight of gas from the low-pressure stage to the high-pressure stage than in the opposite direction and thus the hot gases are delivered to the heat-absorbing part 10 at a lower pressure than prevails in the furnace. According to the invention, the surplus gas resulting in the furnace from the pressure-exchange is by-passed directly, e.g. by a duct 19, to a low-pressure region 20 located before, or comprising, the inlet to the heat-absorbing parts 10 and in this region the gas, being injected by a nozzle 21, draws with it and compresses the hot gas from the casing outlet 4 so that hot gas at high velocity passes through conduits of the heatabsorbing parts 10. The low-presurse hot gas from the outlet 4 is pre-compressed by a jet from a nozzle 25 fed by bleeding gas from the pressure-exchanger. As shown, cold air enters the exchanger at the inlet 3 and in a compressed state passes from an outlet 6 by a duct 8 to the furnace 7 to be used for combustion and maintain the pressure therein above atmospheric, the pressure in the heat-absorbing part 10 being about atmospheric. In a modification, Fig. 2 (not shown), the pressure in the furnace is about atmospheric, and in the heat-exchanging part 10 it is lower than this, duct 8 and the outlet 6 being unconnected but open to atmosphere and the outlet of the part 10 being connected to the inlet 3 so that the pressure-exchange is between fresh and spent combustion gases with the latter discharging at 6. The fraction of the hot gases which passes through the pressure-exchanger may be pre-cooled to prevent damage to the exchanger. The jet pump 20, the various ducts and the exchanged casing 2 are air or watercooled, Fig. 5 (not shown). Air or water may flow through the exchanger shaft for cooling.