Heat exchangers are often used to heat low-temperature fluids or to cool high-temperature fluids in industrial processes, such as oil, chemicals, light industry, pharmaceuticals, and energy industry. They vaporize the liquid into steam or condense steam into liquid. The heat exchanger can be a unit device, such as a heater, a cooler and a condenser, and also can be a component of a process equipment, such as a heat exchanger within the ammonia synthesis tower. Heat exchanger is an important unit of chemical production equipment, according to statistics, the heat exchanger tonnage is about 20% of the entire process equipment even up to 30%, so its importance can be imagined.
Shell and tube type heat exchanger (also called tubular heat exchanger) main component are a shell, heat exchanger tube,tube sheets and the head part. The shell is round, with internal parallel tube or spiral pipe (twisted tube), The tubes are fixed on tube sheet at the end parts.
Shell and tube heat exchanger is a large quantity and a wide range of products and now urgent need for new wear resistance, corrosion resistance, high strength materials. In China, the development of stainless steel, copper alloy composite material, aluminum magnesium alloy and silicon carbide and other non-metallic materials all have different degrees of progress, especially the development of titanium material is faster. Titanium has better corrosion resistance to seawater, chlor alkali and acetic acid. If the heat transfer is enhanced, the effect will be better. Some manufacturing units have better mastered the processing and manufacturing technology of titanium materials. Spraying the material, our country has imported the production line from abroad. Aluminum magnesium alloy has high corrosion resistance and heat conductivity, the price is cheaper than titanium material, should be noted. In China, remarkable achievements have been made in improving the performance of heat exchangers, increasing heat transfer efficiency, reducing heat transfer area, reducing pressure drop and improving the thermal intensity of equipment. The large use of the heat exchanger effectively improves the utilization ratio of the energy, reduces the cost of the enterprise and improves the efficiency.