METHOD OF PRODUCTION INNOVATIVE HEAT EXCHANGERS WORKING IN EXTREME CONDITIONS

Description

[0001] The present invention is a method of production innovative heat exchangers working in extreme conditions.

[0002] The Chinese patent specification no. CN105772372 presents an anticorrosive method for heat exchangers which enables for regeneration of corroded and rusted heat exchangers by grinding, acid etching, cleaning, pre-drying, spraying of powders and secondary drying. Regeneration allows acquiring the time of the usage of an exchanger again to 1,000 hours.

[0003] The Korean patent specification no. KR20160098157 presents a tubular heat exchanger with high strength and corrosion resistance, and a method for its production.

[0004] The Taiwanese patent specification no. TWM525434 presents a corrosion-resistant plate heat exchanger which is made entirely of stainless steel. Bronze is used as a binder for soldering.

[0005] The Japanese patent specification no. JP2016132711 presents an agent for coating of heat exchangers, which guarantees corrosion and high temperature resistance. The coating consists of (A) epoxy resin, (B) phenolic resin which contains one or more of the following components: phenol and allyl ether or phenol and alkylphenol ether, and (C) metallic mixtures made of one or more compounds selected from zinc, manganese and copper compounds.

[0006] The Korean patent specification no. KR20160115662 presents a method for the production of heat exchangers based on aluminium alloy, which is resistant to corrosion.

[0007] The British patent specification no. GB1065030 presents a method for reducing corrosion of metals in heat exchangers on which flowing fluid affects. The reduction of corrosion is made by increasing the flow speed of fluid on the metal surface by the addition of hydrogen to the flowing fluid.

[0008] The international patent specification no. WO2011006613A2 presents a heat exchange module and compact heat exchangers. The invention relates to a new compact module of heat exchange of heat exchangers, which include at least two heat exchange modules.

[0009] The American patent specification no. US4117884 presents a tubular heat exchanger, and a method for its production. A tube assembly of heat exchange includes many of heat exchange tubes placed in the vertical and horizontal directions in a cumulative way. The end parts of the aforementioned tubes are placed at both ends in the wall hardened with elastic material.

[0010] The Swiss patent specification no. CH585887 presents a tubular heat exchanger consisting of glass tubes and silicone rubber. The exchanger consists of two metal frames. Between the frames, there are tubes made of silicate (e.g. glass). They are tightly embedded in a wall made of hardened flexible plastic. Plastic walls may be covered by a plate or film. The film may be made of a plastic, for example, Teflon, or of the metal plate with holes for the tubes. The gap between the plate and the wall is filled with the same material as the walls.

[0011] The international patent specification no. WO2010044723A2 presents a plate heat exchanger which includes a package of plates of a heat exchanger.

[0012] The conception of the invention is to develop a new method-the corrosion protection of industrial components with a usage of a protective coating, and heat exchangers operating at elevated and high temperatures in the corrosive environment which consists of sulphur compounds or in the offshore conditions at the working temperature approx. 80 °C.

[0013] The conception of the invention is that an anticorrosive protective coating is sprayed or deposited manually on the outer surface of tubes of heat exchangers. The protective coating consists of two layers:

• the first layer (the primer layer) is the heat-resisting ground Termo-Grunt which is based on silicone resin of thixotropic consistency with stabilizing additives, and pigmented with aluminium and zinc dust. The content of solid matter does not exceed 60% of volume. The thickness of the primer layer should not exceed 100 µm (dry) or 190 µm (wet);
• the second layer (the surface layer) is made of the paint Termo- Emalia based on silicone resin of thixotropic consistency with stabilizing additives, and pigmented with aluminium dust. The content of solid matters does not exceed 40% of volume. The thickness of the surface layer should not exceed 100 µm (dry) or 275 µm (wet). The time of painting of the layers amounts from 10 up to 48 hours depending on the humidity of the environment. After painting the coating is hardened thermally at 200 ° C for at least 2 hours. The thickness of the dry depositing anticorrosive protective coating amounts from 10 µm up to 400 µm, preferably 200 µm.

[0014] In a different variant, the conception of the invention is that an anticorrosive protective coating, the Blygold PoluAl-XT coating based on polyurethane with the addition of aluminium (the thickness of the depositing anticorrosive protective coating amounts from 1 µm up to 400 µm, preferably 200 µm), is deposited manually or automatically on the outer surface of tubes of heat exchangers.

[0015] By using thermal spraying the casings of exchangers are additionally coated with a protective coating 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 amounts from 10 µm up to 400 µm.

[0016] An advantage of the conception of the invention is the protection against the corrosion of industrial components of heat exchangers working at elevated and high temperatures in the corrosive environment.

[0017] The use of anticorrosive protective coating based on the conception of the invention makes that the heat transfer coefficient of the given heat exchanger is 7.5% lower than an exchanger without the deposited coating, however, the heat exchanger is significantly more resistant to extreme conditions.

[0018] The invention can be used in making protective coatings on the tubes of heat exchangers. The coating can be used on tubes in heat exchangers in installations in which during the process of heat recovery, there is an elevated or high temperature and complex corrosive atmosphere, for example hot flue gas (energy industry). The anticorrosive protective coating protects tubes against high temperature corrosion (operating temperature of the exchanger is up to T = 800 ° C) in the air atmosphere and in the complex industrial atmospheres containing SO₂ (≤ 0.1%), CO (≤ 15%) and HCl (≤ 0.5%).

[0019] The conception of the invention can be used as an exchanger in a cooler of transformer oil, which works in the offshore conditions.

[0020] The conception of the invention is shown in the following examples.

Example 1

[0021] An anticorrosive protective coating is sprayed or deposited manually on the outer surface of tubes of heat exchangers. The protective coating consists of two layers:

• the first layer (the primer layer) is the heat-resisting ground Termo-Grunt which based on silicone resin of thixotropic consistency with stabilizing additives, and pigmented with aluminium and zinc dust. The content of solid matter does not exceed 60% of volume. The thickness of the primer layer should not exceed 100 µm (dry) (190 µm (wet));
• the second layer (the surface layer) is made of the paint Termo- Emalia based on silicone resin of thixotropic consistency with stabilizing additives, and pigmented with aluminium dust. The content of solid matters does not exceed 40% of volume. The thickness of the surface layer should not exceed 100 µm (dry) (275 µm (wet)). The time of painting of the layers amounts from 10 to 48 hours depending on the humidity of the environment. After painting the coating is hardened thermally at 200 ° C for at least 2 hours. The thickness of the depositing anticorrosive protective coating is 200 µm.

Example 2

[0022] An anticorrosive protective coating, the Blygold PoluAl-XT coating based on polyurethane with the addition of aluminium (the thickness of the depositing anticorrosive protective coating amounts from 1 µm up to 400 µm, preferably 200 µm), is deposited manually or automatically on the outer surface of tubes of heat exchangers.

Example 3

[0023] By using thermal spraying the casings of exchangers are additionally coated with a protective coating 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 is 200 µm.

Claims

1. Method of production innovative heat exchangers working in extreme conditions with a usage of coating deposition, characteristic in that, an anticorrosive protective coating is sprayed or deposited manually on the outer surface of tubes of heat exchangers. The protective coating consists of two layers:

- the first layer (the primer layer) is the heat-resisting ground Termo-Grunt which is based on silicone resin of thixotropic consistency with stabilizing additives, and pigmented with aluminium and zinc dust. The content of solid matter does not exceed 60% of volume. The thickness of the primer layer should not exceed 100 µm (dry) or 190 µm (wet);

- the second layer (the surface layer) is made of the paint Termo-Emalia based on silicone resin of thixotropic consistency with stabilizing additives, and pigmented with aluminium dust. The content of solid matters does not exceed 40% of volume, thickness of the surface layer should not exceed 100 µm (dry) or 275 µm (wet);

The time of painting of the layers amounts from 10 to 48 hours depending on the humidity of the environment. After painting the coating is hardened thermally at 200 ° C for at least 2 hours. The thickness of the dry depositing anticorrosive protective coating amounts from 10 µm up to 400 µm, preferably 200 µm.

2. Method of production innovative heat exchangers working in extreme conditions working in extreme conditions with a usage of coating deposition, characteristic in that, an anticorrosive protective coating - the Blygold PoluAl-XT coating based on polyurethane with the addition of aluminium (the thickness of the depositing anticorrosive protective coating amounts from 1 µm up to 400 µm, preferably 200 µm), is deposited manually or automatically on the outer surface of tubes of heat exchangers.

3. A method according to claim 2, characteristic in that, by using thermal spraying the casings of exchangers are additionally coated with a protective coating 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 amounts from 10 µm up to 400 µm.