SU884916A1 - Method of manufacturing welded shell-and-tube heat exchanger - Google Patents

Description

(54) METHOD OF MANUFACTURING A WELDED SHELL-TUBE HEAT EXCHANGER

one

The invention relates to welding, in particular, to methods for producing a welded shell-and-tube heat exchanger, primordially for aggressive media, and can be used in the manufacture of an air preheater for boiler units operating on sulfur fuel in the chemical and other sectors.

A known method of manufacturing a shell-and-tube heat exchanger for corrosive media with an anticorrosion coating applied to metal pipes and then assembling them into a rigid bundle using intermediate elements in the form of threaded bushings that are screwed into the holes of the tube board to press the stuffing box sealing the junction .ij.

This method allows to preserve the integrity of the anticorrosion coating, but it is technologically complex, unreliable because of the possibility of leakage through the glands at high temperatures and does not provide the possibility of applying an anticorrosive coating to the end of the pipe.

Also known is a method of making a welded shell-and-tube heat exchanger, preferably for corrosive media, closest to the proposed invention in its technical nature, in which an anticorrosive coating is applied to the inner surface of the heat exchanger tubes.

10 cover and weld them to tube plates 2j.

The disadvantages of the method include the fact that this technology requires welding to the pipes of intermediate thin-walled plates.

This method preserves the integrity of the anti-corrosion coating, but does not provide the possibility of applying a reliable high-quality anti-corrosion coating.

Claims (2)

20 at the end of the pipe, which is especially important for the cold end of the pipe at the point where the flue gases exit. For example, during the operation of the boiler in transitional regimes (during stoving and stopping), as the flue gas temperature decreases, sulfuric acid vapor condenses in the cold part of the air preheater. Stack, acid cause intense corrosion of welds (places 11p5s are rough to a rough board) and pipe ends. FfapjiueHHe weld density leads to an increase in Boaawa suction cups in the air heater, making it more economical to work on, manufactured and welded intermediate plates entails an additional consumption of materials. In addition to Toio, the method of heat exchange with the installation of intermediate thin-walled plates significantly increases the workability of the fabric. the need for additional production of intermediate elements, at the same time dramatically increases the volume of welding work, and more The effectiveness of welds leads to a decrease in the reliability of the work of heat exchange due to wa leaks. The purpose of the invention is to simplify the technology of manufacturing and improving the quality of the heat exchanger. For manufacturing in the manufacturing method of a welded shell-and-tube heat exchanger, it is important for corrosive media, where an anti-corrosion coating is applied to the inner surface of the heat exchanger tubes and welded them to tube plates, at least on one side of the tubes, wholeness is performed on their end sections 1-foot lens-shaped expansion joints in the form of a looped flange with rad11us and straight length, the thickness of the pipe walls, an anti-corrosive coating applied to the inside surface of the pipes on the outer surfaces flanging sections, and welding pipes with tube plates are located on the straight flanging sections. On ftg. 1 shows a heat exchanger tube with a pre-flanged first junction) end section; on 4sir. 2 - the same; with finally s44orm {forvano lens compensator (second transition); in fig. 3 - pipe coated with anti-corrosion coating; in fig. 4 plot izgotoshgenii kozhukhotrubnogo teploptemagika. Example. The heat exchanger, for example, the air heater of a boiler unit operating on sulfur fuel, is made of metal rub. 1 with entrained1 anticorrosive} coating, HanpHNtep acid-resistant emu 2. - Up to the seam on the pipe coatings on the end sections of the pipes from one side. (on the cold side), one-piece lens compensators are made in the form of a loop-like flange3. The lens compensator is formed in two periods. The molding is carried out without preheating the tube. A preliminary punching flap is done right at the right angle of the pipe section (figure 1), then the second punch finally forms a loop-like flanging (figure 2), after which the flanged end of the pipe is cut to size to ensure its fastening along the entire length of the surface to the tube plate. Beaded lintels, but the pipe 1 is coated with an anticorrosive coating 2, for example enamel (Fig. 3). The radius of flanging and the length of its straight section are set equal to the wall thickness of the pipe. The anticorrosion coating is applied simultaneously from the BiiyTrenni side of the pipes and from the outside of the lens compensators, while the straight section of the compensator is left uncoated. The assembly of the bundle is accomplished by welding the straight sections of flanging the tubes 1, which are not coated, to the tube plate 4. The second ends of the tubes (upper part of the heat exchanger) are welded directly to the tubes E boards, since they are not threatened with corrosion. for the reason that the temperature of the walls of the inlet (by gases) pipe sections exceeds the dew temperature by no less than. . The use of air heaters with enamelled tubes, which extend the lens compensators made by the proposed method, will simplify the technology of their manufacture, improve the quality of the anticorrosive coating of pipes, and significantly increase the service life of tedlomeynikov. The invention The method of manufacturing a welded shell-and-tube heat exchanger, mainly WG corrosive media, in which an anti-corrosion coating is applied to the surface of the heat exchanger tubes and welded to the tube plates, I distinguish