Safe operation of air separation unit

At present, there are two types of common condensing evaporators in domestic air separation units, plate fin condensing evaporator and tubular condensing evaporator. Tubular condensing evaporator is divided into three types: long tube, short tube and coil. The long tube and short tube are all in row. The tube is made of red copper and the tube sheet is made of brass. It is generally used in small and medium-sized air separation plants. Coil type is generally used for auxiliary condensing evaporator. Because there is no fixed liquid level in the coil, the heat transfer coefficient is small, so it has been gradually eliminated. The plate fin condenser evaporator is made of all aluminum structure, and the plate unit is arranged in vertical star shape. Its characteristics are compact structure, light weight, small volume and easy to manufacture. It is widely used in large and medium air separation plants. Due to the gradual enlargement of the air separation unit, the heat excha

Temperature difference is the power of heat transfer. As long as there is temperature difference between two materials, they will carry out the heat or cold transfer spontaneously. The heat is always transferred from the fluid with higher temperature to the lower temperature fluid. Although the heat transfer process of various heat exchangers is not identical, the heat transfer law is basically the same. The following is an example of the most widely used dividing wall heat exchanger: heat is transferred from hot fluid to cold fluid through the wall and flows in the opposite direction. The whole heat transfer process is divided into three stages. In the first stage, convection heat transfer: the heat flow body transmits heat to the wall surface. This process not only has heat transfer caused by the relative displacement of each part of the fluid, but also has heat conduction in the fluid, which is the comprehensive function of convection and heat conduction. In the second