Patent GB-1150165-A (GB)
Title: Supercharged Vapor Generator.
IPC: F22B1/22
Filed: 1966-05-23
Abstract: 1,150,165. Once through steam generators; supplying combustion air; tubular heat exchangers. FOSTER WHEELER CORP. 23 May, 1966 [10 June, 1965], No. 22950/66. Headings F4A, F4B and F4S. A once through forced flow steam generator comprises a circular cross-sectioned outer containment shell 21, having left and right vertical portions 23, 25 respectively, a central vertical portion 29, and a connecting horizontal portion 27. A chamber 30 formed of gas tight finned tubes welded together is located within the shell 21 and comprises left and right cylindrical sections 31, 47 having bell-shaped ends 37, 48 respectively, a horizontal rectangular section 50 and a central vertical rectangular section 56. The space between the shell 21 and the chamber 30 defines an annular air passageway 39, compressed air from compressor 161 passing through air inlet ports 143 in central vertical portion 29 to flow along passageway 39 to be preheated. The air is then delivered to burners 45 at the bottom of left and right cylindrical sections 31, 47 through air exit ports 146, 150, air conduits 147, 151 and air re-entry ports 148, 152 respectively. The combustion products from the burners 45 flow through the inside of chamber 30 to gas exit ports 155 in chamber 153 at the bottom of central vertical portion 29 to pass to a gas turbine 159 which drives air compressor 161 through conduit 158 and auxiliary combustor 157. From the gas turbine 159 the gas is exhausted to a stack 163 containing an economizer 110. Water from economizer 110 enters ring shaped inlet headers 108, 109 at the bottom of left and right cylindrical sections 31, 47 respectively and flows through the boiler tubes to lower left and right enthalpy equalizing mixing headers 106, 107 respectively. From these headers the fluid flows in a second pass to upper left and right enthalpy equalizing mixing headers 111, 112 respectively. From the upper enthalpy equalizing mixing headers the fluid flows in a third pass, partly to left and right collection headers 113, 114 respectively, located in the middle of the horizontal rectangular section 50, and partly to a pair of central collection headers 117 located at the top of the central rectangular vertical section 56. From the left and right collection headers 113, 114, the fluid flows through the tubes of the central rectangular vertical section 56 to ring shaped outlet header 116 at the bottom of that section. Fluid from the central collection headers 117 flows directly to the ring shaped header 116 through conduits 115. The fluid then flows through primary superheater bank 65 in central rectangular vertical section 56 from inlet headers 67 to ou tlet headers 69. The flow then divides into two equal parts, part passing through conduit 121 and branch 122 to the inlet header 72 of left finishing superheater 71, pendantly mounted in the left hand side of the horizontal rectangular section 50, and part similarly through conduit 121 and branch 123 to the inlet header 80 of right finishing superheater 76 pendantly mounted on the right hand side of horizontal rectangular section 50. From the outlets 74, 78 of the left and right finishing superheaters 71, 76 respectively, the flow is recombined to pass to a high pressure turbine stage 126. The partly expanded steam from this stage is again divided into two equal flows, part passing through left control shell and tube heat exchanger 81 to control the final reheat steam temperature by heat exchange with superheated steam, and then the left pendant primary reheater 79 mounted in the left hand part of horizontal rectangular section 50, and the other part passing through a similar right control shell and tube heat exchanger 84 and then right primary reheater 83. From the primary reheaters 79, 83 the flows recombine to pass through a finishing reheater bank 66 from inlet 70 to outlet 68, whence the flow passes to the intermediate and low pressure turbine stages 127, 128 respectively. Condensate from condenser 138 is passed by pump 139 through low pressure feed heaters 140 to a second pump 142 and so back to economizer 110. Part of the superheated steam flow from primary superheater outlet header 69 to inlet header 72 of the left finishing superheater 71 is by-passed through conduit 130 and inlet 95 to the U-tubes 90 of the left control shell and tube heat exchanger. This fluid is then returned to the inlet header 72 through outlet 96 separated from the inlet by partition 97. Reheat steam from the high pressure turbine stage 126 enters the shell side of the heat exchanger through conduit 98 and is dispersed over the U-tube bank 90 by perforated sheet 99 on its way to the tubes of the left primary reheater 79. The right control shell and tube heat exchanger is similarly arranged, supplied and constructed. The superheater steam flows through the tube sides of the heat exchangers are controlled by valves (133, 134, Fig. 7, not shown) to maintain the desired final reheat steam temperature. The shell 21 and the chamber 30 are downwardly supported on rods 105 from a structural framework.