Local reinforcing method for plate heat exchanger

Abstract

The invention relates to the technical field of heat exchange, and aims to provide a plate heat exchanger local reinforcing method which comprises the following steps: S1, filling clay between two attached plates in a leakage area; s2, the clay is taken out after being shaped and measured, and the boundary dimension of the reinforcing rib is obtained; s3, a reinforcing rib entity is manufactured according to the obtained boundary dimension of the reinforcing rib; s4, removing foreign matters on the surfaces of the sheet bars and the reinforcing ribs, and then cleaning the sheet bars and the reinforcing ribs with acetone; and S5, 0.1 mm pure titanium welding wires are added to the weld joints, and the plates and the reinforcing ribs are welded and fixed in a cold welding mode. The external gap internal structure of the sheet is obtained by adopting the ultra-light clay, and meanwhile, the welding quality is improved, the welding difficulty of the sheet is solved, the bottleneck in the titanium metal welding field is broken through, and the problem that the plate heat exchanger in a clean liquid workshop of a factory frequently leaks is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat exchange, and particularly relates to a method for locally reinforcing a plate heat exchanger. Background Art

[0002] The working principle of a plate heat exchanger is to achieve heat exchange through plate sheets for the purpose of heating or cooling a liquid. In the electrolysis workshop of our company, the copper sulfate solution needs to be heated to 70 - 80 °C for use in the purification process. Our factory uses steam directly connected to the heat exchanger for heating the copper sulfate solution. Previously, the plate sheets of the plate heat exchanger used were Hastelloy (254SMO), and the plate sheets of this material were extremely susceptible to corrosion by the copper sulfate solution containing high-concentration copper ions. Therefore, the plate sheet material was upgraded to pure titanium plate sheets, and the corrosion resistance problem was significantly improved during use. However, since the plate sheet material is pure titanium, and the steam temperature is above 180 °C, and the outlet temperature of the copper sulfate solution is around 70 °C, the overall temperature difference of the plate sheet changes greatly, and local weak parts will deform over time resulting in leakage, especially at the outer side of the steam inlet and the outer side of the copper sulfate solution outlet, where leakage is extremely likely to occur, and basically all leaks occur in this weak link. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for locally reinforcing a plate heat exchanger to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is:

[0005] A method for locally reinforcing a plate heat exchanger includes the following steps:

[0006] S1: Stuff clay between two adjacent plate sheets in the leakage area;

[0007] S2: After the clay is shaped, take it out, measure it, and obtain the external dimensions of the reinforcing rib;

[0008] S3: According to the obtained external dimensions of the reinforcing rib, fabricate a solid reinforcing rib;

[0009] S4: First remove foreign matters on the surfaces of the plate sheet and the reinforcing rib, and then clean them thoroughly with acetone;

[0010] S5: Add a 0.1 - mm pure titanium welding wire at the weld, and use the cold welding method to weld and fix the plate sheet and the reinforcing rib.

[0011] The clay used is ultra - light clay.

[0012] In the step S3, the material of the solid reinforcing rib is a titanium bar.

[0013] In step S5, the model of the cold welding machine during cold welding is HS-ADS02.

[0014] The specific parameters of the cold welding machine are as follows: mode 4, welding current 40A, and pulse time adjusted to 25ms.

[0015] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0016] The present invention obtains the internal structure of the external gap of the plate by using ultra-light clay, and at the same time, with the welding method of cold welding, the welding quality is improved, the welding difficulty of thin plate sheets is solved, the bottleneck in the field of titanium metal welding is broken through, and the problem of frequent leakage of the plate heat exchanger in the purified liquid workshop of our factory is solved. Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of the reinforcing rib obtained in the embodiment of the present invention.

[0018] Figure 2 It is an effect diagram of installing the reinforcing rib on the plate in the embodiment of the present invention. Detailed Embodiments

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] For a better understanding of the present invention, the following explanations are made:

[0022] By analyzing the structure of the plate, the main reason for leakage is that the local deformation of the titanium plate is caused by the excessive liquid temperature at the outer positions of the air inlet and the acid outlet, resulting in leakage at the sealing rubber strip. It is necessary to reinforce this place to improve the strength and prevent local deformation from causing leakage. If considering customizing and widening both sides of the titanium plate, the cost of each titanium plate will increase from the original 20,000 yuan to 40,000 yuan, and the cost of a plate heat exchanger with 40 plates will increase by 800,000 yuan per set. After installing this plate, all the plates need to be replaced every six months, and the annual cost of the plates alone will be 800,000 yuan (20,000 yuan per piece, a total of 40 pieces).

[0023] To solve the above problems and reduce the cost of the plate at the same time, local reinforcing ribs are added inside the leakage part of the plate to improve the local strength and durability, so as to prevent leakage caused by local deformation.

[0024] Embodiment

[0025] The present invention provides a method for locally reinforcing a plate heat exchanger, which includes the following steps:

[0026] S1: Since the structure of the plate is complex, the size and shape of the reinforcing ribs have high requirements. After welding the reinforcing ribs, it is necessary to ensure both unobstructed channels and the fit between the plates. Therefore, ultra-light clay is used to fill the space between two fitting plates in the leakage area;

[0027] S2: After the ultra-light clay is shaped and taken out, the void structure outside the leakage area can be obtained. Through measurement and optimization, the external dimensions of the reinforcing ribs can be obtained (as Figure 1 shown), with the size of 260*20*8mm;

[0028] S3: Titanium bars are used as materials to make the reinforcing ribs to obtain solid titanium reinforcing ribs;

[0029] S4: Also, since titanium and titanium metals are active metals and the thickness of the plate is only 0.75mm, it is very difficult to firmly weld the reinforcing ribs to the two plates. Innovatively, an HS-ADS02 cold welder is used for welding. During welding, foreign matters on the surface of the plate and the reinforcing ribs are first removed, and then it is cleaned with acetone;

[0030] S5: Adjust the cold welder to mode 4, the welding current is 40A, the pulse time is adjusted to 25ms, a 0.1mm pure titanium welding wire is added at the weld, and the appropriate parameters are adjusted to weld and fix the titanium plate and the titanium reinforcing ribs.

[0031] After the implementation of the present invention, in our factory, the situation where the plates need to be replaced once every six months can be improved. Through this method, the service life of the plates can be extended by 1 year, reaching 1.5 years for plate replacement once. It can save 800,000 yuan in spare parts costs per year, ensure the continuous operation of the production system, reduce the labor intensity of the operators, improve the welding skills of the welding personnel in our factory, and also overcome the welding process of thin titanium plates.

Claims

1. A method for local reinforcement of a plate heat exchanger, characterized in that, It includes the following steps: S1: Stuff clay between two fitting plates in the leakage area; S2: Take out the clay after it is shaped, measure it, and obtain the external dimensions of the stiffener; S3: Make the stiffener entity according to the obtained external dimensions of the stiffener; S4: First remove the foreign matters on the surfaces of the plates and the stiffener, and then clean them with acetone; S5: Add a 0.1 mm pure titanium welding wire at the weld, and fix the plates and the stiffener by welding in a cold welding manner.

2. A method for local reinforcement of a plate heat exchanger according to claim 1, characterized in that: The clay used is ultra-light clay.

3. A method for local reinforcement of a plate heat exchanger according to claim 1, characterized in that: In step S3, the material of the stiffener entity is a titanium bar.

4. A method for locally reinforcing a plate heat exchanger according to claim 1, characterized in that: In step S5, the model of the cold welding machine in the cold welding process is HS-ADS02.

5. A local reinforcement method for a plate heat exchanger according to claim 4, characterized in that: The specific parameters of the cold welding machine are: mode 4, welding current 40 A, and pulse time adjusted to 25 ms.

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