Purpose of large air separation unit

The main causes are as follows: 1. The structure is unreasonable, the welding seam is concentrated and the welding joint stress is too large. 2. When welding, the molten pool is too large and overheated, and the alloy is burnt too much. 3. The arc crater is not filled due to too fast arc closing and too early wire drawing. 4. Material problems, for example, when Mg content is less than 3%, and impurities such as Fe and s exceed the standard, it is easy to cause cracks. When the melting temperature of welding wire is too high, liquefaction cracks in heat affected zone are easy to occur. Preventive measures include: 1. During the design, attention should be paid to the reasonable arrangement of welding seams, avoiding the stress concentration as far as possible, and selecting the welding sequence reasonably. 2. Reduce welding current or increase welding speed properly. 3. The arc stopping operation technology should be correct, and the arc pit should be filled by adding the ou

Almost all motors commonly used in the air separation plant are three-phase AC motors. Three-phase AC motor can be divided into asynchronous motor and synchronous motor. The rotating speed of the synchronous motor and the frequency of the power grid keep a strict relationship, namely: N = 60f/P in the formula P -- magnetic pole logarithm; f -- grid frequency, the normal situation is 50Hz; n -- motor speed, r/min. For example, for two-pole (P = 1) synchronous motor, the synchronous speed is 3000r/min; for four-pole motor, P = 2, n = 1500r/min. While the rotating speed of asynchronous motor is always less than that of synchronous motor, and it generates rotating torque by its phase difference. Asynchronous motor is most widely used. It consists of a stator and a rotor, and has a stator and a rotor winding respectively. The stator winding is made of copper (aluminum) wire with outsourcing insulation. With the difference of rotor winding, asynchronous motor can be divided into squirrel ...