UNIT AIR COOLER is one of the widely used heat transfer equipment, which has the characteristics of high heat transfer efficiency, compact structure, small footprint, convenient installation and maintenance combination, etc. Widely used in electric power, petroleum, chemical industry, metallurgy, machinery, light industry, food, medicine, electric power, painting, shipbuilding, electromechanical, textile, papermaking, heating and other industrial sectors. UNIT AIR COOLER creates a net contact in the fluid channel. Fluid turbulence is strong, which enhances heat transfer and increases the rigidity of the plate, so that the plate cooler can withstand a large pressure difference between the cold and hot medium channels.
The leakage of UNIT AIR COOLER is mainly caused by corrosion, and a small part is due to defects in model selection and its own manufacturing process. There are basically two forms of corrosion: electrochemical corrosion and chemical corrosion. During manufacture, manual arc welding is generally used for welding tube sheets and tubes. There are different degrees of defects in the shape of the weld, such as depressions, pores, slag inclusions, etc. Weld stress distribution is uneven. Tube sheets are generally in contact with industrial cooling water during use, but there are impurities and impurities in industrial cooling water.
This is what we often call electrochemical corrosion. Studies have shown that industrial water, whether it is fresh water or sea water, will contain various ions and dissolved oxygen, among which changes in the concentration of chloride ions and oxygen will play an important role in the corrosion form of metals. In addition, the complexity of the metal structure can also affect the corrosion morphology.
Therefore, UNIT AIR COOLER pitting corrosion and crevice corrosion are the main corrosion of the weld between the tube sheet and the tubes. From the outside, there will be many corrosion products and deposits on the surface of the tube sheet, and pits of different sizes are distributed. Galvanic corrosion also occurs when seawater is used as the medium. Chemical corrosion is the corrosion of the medium, and the tube sheet will be corroded by various chemical media.