Air separation parts FAQ

Saturation temperature and saturation pressure are terms in gas-liquid equilibrium. If it is not filled with liquid in a sealed container, part of liquid molecules will enter the upper space, which is called "evaporation ". As the number of vapour molecules in space increases, the pressure of vapour generated by it also increases. At a certain time, the number of vapour molecules in space will not increase any more. At this time, the number of molecules leaving the liquid and the number of molecules returning the liquid from Space reach a dynamic balance, which is also called "saturated state ". At this time, the pressure generated by vapour is called "saturated pressure ". For the same substance, the saturation pressure is related to the temperature. The higher the temperature is, the greater the energy the molecule has, the easier it is to get rid of the liquid and gasification, and the corresponding saturation pressure is also higher. A certain temperature corresponds to a certai...

In the air separation plant, the adsorption capacity of the adsorbents is expressed by static adsorption capacity and dynamic adsorption capacity. The static adsorption capacity is the largest amount of adsorbed substance when the adsorbents per unit mass (or unit volume) reach the adsorption equilibrium under certain temperature and certain concentration of absorbed components, that is the ratio of the maximum adsorptive capacity (equilibrium value) that can be reached by the adsorbents to the adsorbents. The dynamic adsorption capacity is the adsorptive capacity when the absorbents reach the "conversion point" (expressed by the average adsorptive capacity per unit of absorbents in the adsorber ). Generally, it is calculated by "conversion time", that is, the time from the fluid contacting the absorbents layer to the "conversion point. "Turning effect point" is the point where the concentration of absorbed component increases obviously when fluid flows out of the absorption layer. ...

Before starting, the following preparations should be done first: 1) Check whether the unit has the starting conditions (including the reason of last stop and the condition of overhaul; check whether there are obstacles around the unit; whether the starting tools, listening needles, recording tables and so on are ready); 2) Check whether the motor, electric, instrument and lighting signal are normal, especially whether the accident chain system can act correctly (including water break, low oil pressure, axial displacement, etc.); 3) oil supply lubrication system is normal (fuel tank oil level, fuel tank bottom whether the water, auxiliary oil pump and oil circuit normal); 4) conditions of cooling system and cooling water (including whether the cooler valve is flexible, water supply pressure and water volume, etc.); 5) whether various valves are flexible and easy to use, and whether they can be closed or opened as required; 6) turn the wheel before starting, check whether the rotatin...

Air compressor intermediate cooler is generally shell-tube structure. Water is supplied inside the pipe, and gas is supplied between the pipes, which plays a cooling role through the heat exchange of fluid inside and outside the pipe. The reasons that affect the cooling effect of compressor intermediate cooler include: 1) insufficient cooling water. The heat of the air is not enough to be taken away by the cooling water, resulting in the increase of the next level of suction temperature, the decrease of gas density, and finally the reduction of exhaust volume. Therefore, the water supply pressure of cooling water should be closely monitored during operation to control the water supply. The process generally requires that the cooling water pressure should be greater than 0.15MPa (surface pressure); 2) the cooling water temperature is too high. High water temperature reduces the temperature difference between water and gas, and reduces the effect of heat and cooling. Even if the amoun...

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 ...

When the general motor in the air separation plant is started, the current that the stator of the motor takes from the power grid is about 5 ~ of the rated current of the motor ~ 7 times. After starting the small motor for one or two seconds, the current decreases rapidly as the rotating speed of the rotor gradually rises; while the large motor needs more than ten seconds, even dozens of seconds before the rotor reaches the stable rotating speed. That is, until the start-up ends, the current drops to the rated value. If the starting current of asynchronous motor is high, what problems will it bring to the use? If this motor starts frequently when it is used, the motor will heat severely due to the influence of starting current, which will affect the normal service life of the motor. In addition, if the starting times of the motor used are not frequent, when its capacity exceeds 30% of the power transformer capacity, due to the large starting current, it will cause the overvoltage dr...