LIGHTWEIGHT EXCHANGERS FOR HEAT RECOVERY: A GAS-GAS RECUPERATOR AND A GAS-FLUID ECONOMIZER, AND A METHOD OF PROTECTION PARTICULARLY AN EXCHANGER CASING

摘要

A lightweight exchanger for heat recovery: a gas-gas recuperator which includes exchanger tubes, a casing and air flow channels, characteristic in that, it consists of the casing (O) in which two air flow channels (K1) and (K2) cross perpendicularly. In the air flow channel (K2) (inside the casing (O)) there are thin-walled exchanger tubes (R) which are placed in parallel. The ends of the tubes are fixed to a perforated bottom (D) by means of adhesive preferably GUMA SWW, two-component polycondensation rubber, in the form of a layer of adhesive (wk) which forms an adhesive connection. For each of the channels (K1) and (K2), the casing (O) has an air inlet (wl1), (wl2) and an air outlet (wy1), (wy2) ended with a montage flange (Km). The casing (O) is made of thin sheet which is firmly connected pointwise by threaded connections (pg) by thermal drilling so that the connection of thin elements is made by the extrusion of a slot with the formation of a bushing, next the threading of the bushing in one of the elements, and then twisting the element with another element. Adhesive preferably GUMA SWW, two-component polycondensation rubber, is used as a layer of adhesive (wk).;A lightweight gas - fluid economizer which includes exchanger tubes, a casing and an air flow channel, characteristic in that, it consists of the casing (O) in which there is a tubular assembly (WR) placed perpendicularly to the gas flow channel (K). There is a bypass channel (KB), with its volume reduced by preferably 25 %, over the tubular assembly in the casing (O). The bypass channel (KB) which is opened or closed by means of movable mechanical blinds (MB). The tubular assembly (WR) is fed with fluid receiving heat through an inlet port of fluid (wlc). The tubular assembly (WR) is ended by an outlet port of fluid (wyc). The inlet port of fluid (wlc) and the outlet port of fluid (wyc) are preferably placed on one side of the tubular assembly (WR) in its axis. The casing is ended at both sides by a montage flange (KM). The gas inlet (wig) and a gas outlet (wyg) of the gas flow channel (K) go through the montage flange (KM).;The method of protection particularly the exchanger casing, characteristic in that, the whole exchanger or a part of it- the outlet part and / or the inlet part and / or the bypass channel is coated with the protective coating (PO) with a gravimetric composition:15% ÷ 17% molybdenum,14.5% ÷ 16.5% chromium,4.0% ÷ 7.0% tungsten,≤ 2.5% cobalt,≤ 0.02% carbon,≤ 1.0% manganese,≤ 0.08% sulphur≤ 0.04% potassium,≤ 0.35% vanadium,the rest is nickel.;The thickness of the depositing protective coating (PO) amounts from 0,1 µm up to 400 µm.