waste heat boiler with zwischenueberhitzer.

摘要

PURPOSE:To produce a constant and fixed gas flow and perform heat recovery effectively by making identical all the diameters of heating tubes for a high temperature side superheater and a high temperature side reheater, or the outside diameters of heating tubes for a low temperature side superheater and a low temperature side reheater, the tube pitches in the transverse direction of a gas duct, the tube pitches in the direction of a gas flow, and the number of tube rows in the direction of said gas flow. CONSTITUTION:With regards to a tertiary superheater 2 and a secondary reheater 3, which are laid out in parallel, the outside diameters of their heating tubes are identically selected together with the tube pitches in the transverse direction of a gas duct, the tube pitches in the direction of a gas flow, and the number of tube rows in the direction of the gas flow so that the same conditions may be afforded to the resistance against the flow of gas in terms of the transverse direction of the gas duct. Similarly, a secondary superheater 4 and a primary reheater 5 which are laid out in parallel on the downstream side of gas are subject to the same condition, since the outside diameters of heating tubes, the tube pitches in the transverse direction of the gas duct, the tube pitches in the direction of the gas flow, and the number of the tube rows in the direction of the gas flow are identically selected, thereby producing the same resistance conditions against the gas flow even in the direction of the gas flow. Furthermore, the draft loss on the gas side is also subject to the same conditions, which fixes the flow of gas constantly. It is, therefore, unnecessary to install and special partition wall exclusively designed to divide the gas pass between these superheaters and the reheaters which are laid out in parallel.