A heat exchanger core group used in acid-base corrosion environment and its coating method

Abstract

The invention discloses a heat exchanger core group used in an acid-base corrosion environment and a coating method thereof. The anti-corrosion coating for the inner cavity of the acid-base heat exchanger adopts phenolic epoxy resin and sealed polyurethane as the main film-forming materials. Polyurethane is a polyurethane curing agent that is stable at room temperature and can release ‑NCO groups when the temperature reaches a certain temperature (unblocking temperature), and cross-links with the epoxy bond of novolac epoxy resin. Excellent mechanical properties and chemical stability, resistant to medium and low temperature strong acids, strong alkalis and sulfates, etc., better resistance to inorganic acids, organic acids, alkalis, salts, organic solvents and hot water than other varieties. The heat exchanger core group is repeatedly sprayed, purged, and baked according to the special coating method of this plan, and finally the paint film is evenly coated on the surface of the heat exchanger fins and heat exchange tubes, which can effectively prolong the life of the heat exchanger. The service life of the core group as a whole in the harsh environment of acid and alkali.

Description

technical field [0001] The invention relates to the technical field of preparation of anticorrosion coatings for acid and alkali resistant heat exchangers and the special coating of heat exchangers, in particular to a heat exchanger core group used in acid and alkali corrosion environments and a coating method thereof. Background technique [0002] In petrochemical, marine machinery, hydropower, thermal power, nuclear power, weaponry and other industries, a large number of heat exchangers are required. Because of the harsh environmental conditions, these equipment are faced with various complex medium corrosion problems; the core group of the heat exchanger is The part with the shortest service life of the heat exchanger, extending its service life can realize the value-added use of the whole heat exchanger. [0003] The heat exchanger core group mainly has finned, tubular and other structures, and its internal structure is tight. It is impossible to coat all parts of the co...

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Problems solved by technology

[0003] The heat exchanger core group mainly has finned, tube-and-tube structures, and its internal structure is tight. It is impossible to coat all parts of the core group evenly by traditional spraying and dipping, and there is a problem of difficulty in construction. On the other hand, Because of the different application scenarios of heat exchangers, their corrosive environments are also different. There is no coating product specially designed for heat exchanger anticorrosion in the market and suitable for various common acid-base media.

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