RU1815592C - Method for sealing class tubes in holes of tube sheet of heat exchange - Google Patents

Abstract

Usage: in the manufacture of apparatus for the chemical, food and refrigeration industries. The inventive simplification of the compaction process and increase the durability of the latter is ensured by the fact that a layer of plastic material is applied to the surface of the tube sheet, mainly polyurethane adhesives without hardener, with a layer 0.3-1.0 mm thick, then glass pipes are inserted Sealing material is poured into the holes of the grate. The method eliminates the need for pre-treatment of the surface of the grating and increases the reliability of the seal. 1 wp Yo

Description

The invention relates to methods for manufacturing heat exchangers containing glass pipes, and can be used in the chemical, food and refrigeration industries.

The aim of the invention is to simplify the compaction process and increase the durability of the latter,

This goal is achieved in that. in the method of sealing glass pipes in the openings of the heat exchanger tube sheet by installing the pipes in the holes of the heat exchanger and pouring sealing surface on its surface, predominantly polyurethane adhesives without hardener 0.3-1.0 mm thick are applied to the surface of the tube sheet.

In well-known pipe-to-pipe connection units, the sealing material is in direct contact with the pipe sheet, and in order to ensure reliable adhesion, the surface of the latter must be specially prepared

 - degreased, coated with primers or adhesive.

In the proposed method, special processing is not required - a layer of plastic material can be applied even to the surfaces of the tube sheets contaminated after machining.

In the absence of plastic material, it would be necessary to specially prepare the surface of the tube sheet for equal adhesion of its entire surface to the layer of sealing material; it can seep into the gaps between the glass pipes and the holes. And with a significant length of glass pipes, their large diameter and significant differences in temperature

Joint venture

Joint venture

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Undesirable linear deformations may occur between the coolants, which reduce the durability of the seal assembly.

The sealing method is carried out as follows.

Glass tubes are inserted into the openings of the tube sheet. The tube sheet is preliminarily coated with an intermediate plastic material, on top of which, after installing the pipes, a layer of sealing material is poured.

A layer of intermediate plastic material is applied by any known method, for example, with a brush or spatula. This material enters the annular gap between the pipe and the hole in the tube sheet, which prevents leakage of the sealing material through the tube sheet down the pipes.

Sealing material, for example, polymer, is poured onto the tube sheet over a plastic material. The cured, polymeric material provides reliable adhesion to glass pipes.

Thus, on the tube sheet, there is, as it were, a second tube sheet consisting of glass pipes rigidly interconnected and a sealing polymer material. This design eliminates the high temperature stresses in the glass pipes caused by a change in their linear dimensions during temperature differences of the heat carriers passing through the heat exchanger.

 The experiments carried out allowed us to conclude that the interval of 0.3-10 mm is the most optimal layer thickness of a plastic material. At a thickness of less than 0.3 mm, a slice of plastic material is mixed with the hardener of the main sealing layer and solidifies, after which it cannot perform damping functions to the seal. To apply a layer with a thickness of more than 1.0 mm is not economically feasible. PRI me R. A layer of polyurethane adhesive without a hardener 0.5 mm thick is applied onto the surface of the tube sheet, which has not been previously treated with primers. Polyurethane adhesive is poured over it.

contribution-11 mixed with a hardener, 5-7 mm thick. After curing, an adhesive that foams and increases in volume by about 2-2.5 times, get

a layer of sealing material showing high adhesive ability with respect to glass pipes and not directly in contact with the tube sheet. Cured Adhesive Layer

a thickness of about 15 mm provides sufficient rigidity of the structure, and the layer of plastic material its elasticity without compromising tightness. When piping hot water with temperature

In the order of 85-90 ° C, no visible deformations of the seal assembly were noted.

The proposed method of sealing glass pipes in the holes of the tube sheets does not require special treatment of the surface of the tube sheet, eliminates temperature stresses and, in addition, allows significant deviations of the diameter and shape of the glass pipes due to the large annular gap between the pipe

and a hole. Heat exchangers of this design can be easily manufactured locally. The most appropriate use is for heat recovery of waste heat carrier equipment

chemical and food industries, for example, dryers, evaporators, etc.

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Claims (2)

1. A method of sealing glass pipes in the openings of the tube sheet of a heat exchanger by installing pipes in the holes of the grid and pouring its surface with a sealing material, characterized in that, p. In order to simplify the compaction process and increase the durability of the latter, a layer of plastic material is previously applied to the surface of the tube sheet. 2. The method according to p. 1. characterized in that as a plastic material. polyurethane adhesives without hardener are used, and their layer thickness is made equal to 0.3-1.0 mm.