GB583749A - Improvements relating to steam superheaters for water tube boilers - Google Patents

Abstract

583,749. Steam superheaters. SUPERHEATER CO., Ltd., and SOUTHCOTT, L. C. Nov. 28, 1944, No. 23692. [Classes 123 (ii) and 123 (iii)] In a steam boiler, primary and secondary superheater sections 20, 21 are located one in each of two vertical and parallel flue gas passages which are defined by partitions 11, 12 and 12 13 and are arranged in series between a furnace chamber 1, cooled by water tubes 2, 3, 4, and a third passage in which is disposed a bank of steam generating tubes 8, extending vertically between an upper steam and water drum 6 and a lower water drum 7, and the flow of flue gases through the superheater is regulated to maintain the' required final steam temperature by a damper-controlled opening or openings 15 in the middle partition 12. The damper or dampers 16 associated with the openings 15 are preferably of the vertically sliding type and may be operated by hand or automatically in response to variations in the final steam temperature. The elements of the superheater, which extend from inlet to outlet headers 17, 18, comprise vertically-extending U-looped tubes, the upper portions 211 of those tubes of the secondary superheater section 21 nearer the furnace being more openly pitched than the other tubes; alternatively all the tubes in this section are spaced to provide wide gas lanes throughout their whole length. The partitions 11, 12, 13 also the partition 14 between the tube bank 8 and economiser 9 in the uptake 10, are supported by water tubes, and the tubes associated with the partition 12 may be employed for mounting spacing and staying means 22 for the superheater elements. The wall tubes 4 at the gas exit from the furnace are opened out at 44 to permit the requisite gas flow, and, preferably, the upper end of the secondary superheater section 21 projects into the path of the gases leaving the furnace. In a modification, the superheater comprises horizontally disposed tube loops arranged to be self-draining into an intermediate header which is located between the two sections thereof and is equipped with a valve-controlled drain connection.