In terms of heat dissipation of spiral plate heat exchangers, copper and aluminum are often better, then steel and cast iron. The material must be considered when purchasing a heat exchanger. We must know that the material will determine its safety, reliability, and the length of life. When purchasing a spiral plate heat exchanger, the merchant should be required to produce a test report on whether the material is corroded and the compressive strength. However, there are often the following misunderstandings in the purchase process.
(1) Aluminum heat exchanger does not corrode
Due to the different corrosion principles of materials, aluminum heat exchangers are not afraid of acid corrosion (oxidation corrosion), but are prone to alkali corrosion and chloride ion corrosion. Therefore, when the water quality of a heating system is alkaline (PH value higher than 7) or the chloride ion content is high (high salt content), the heat exchanger has the hidden danger of corrosion and water leakage. Due to the poor welding performance of aluminum alloys, consumers should avoid using aluminum alloy heat exchangers with welded seams, and purchase full die-cast aluminum alloy heat exchangers to avoid water leakage at the weld seam causing property losses. Because aluminum alloy heat exchangers have different requirements for water quality than steel, avoid mixing aluminum alloy heat exchangers with other materials.
(2) The wall thickness is afraid of corrosion
Cast iron heat exchangers are not easily damaged by corrosion because the cast iron itself has good oxidation and corrosion resistance, not because of the wall thickness. In recent years, some small domestic manufacturers have tried to solve the anti-corrosion problem of steel heat exchangers by increasing the wall thickness. This is completely wrong. Because the corrosion of steel heat exchangers is local corrosion of small holes, rather than uniform corrosion of spiral plate heat exchangers.