DEAR Air separation equipment.According to the expander outlet temperature T2 and pressure P2, the corresponding specific enthalpy H2 can be found from the ordinate. The ideal adiabatic expansion process should be isentropic expansion process. The ideal specific enthalpy value when expanding to the same outlet pressure P2 can draw a vertical line through the state point 1 at the inlet to obtain the intersection 2T of the isobaric line with the outlet pressure P2, which is the outlet state point of ideal expansion. Its specific enthalpy h 2T can be found on the ordinate.In recent years, there are more and more air separation units using molecular sieve purification process, and the main heat exchanger is non switching plate fin heat exchanger. No matter what process the heat exchanger is used for, the arrangement of cold section and hot section is different from that of switching heat exchanger.The determination of the operation cycle of air separation unit is mainly based on the time interval when the trace carbon dioxide is gradually accumulated after it is brought into the air separation tower until it cannot continue to operate due to blockage. Under normal conditions, the continuous operation time of the full low pressure oxygen generator should be more than one year, and the continuous operation time of the new molecular sieve adsorption process can be more than two years.
During the regeneration of Molecular Sieve Purifier, the outlet temperature of nitrogen will continue to rise at the beginning of the cold blowing stage, forming a peak value. However, there are two or three peaks in the cold blowing curve of some adsorbers, or the whole peak is relatively flat and the peak is not obvious.When measuring the pressure of piston compressor and similar equipment, shock absorber must be added in the pipeline to prevent the damage of pressure gauge components. Shock absorber usually uses buffer vessel with orifice, or directly uses needle valve instead of globe valve;The low temperature valve is installed at normal temperature and works at low temperature, with a wide range of temperature variation. If the design and installation is not proper, it is easy to produce thermal stress or deformation. At the same time, the operating part of the valve is at room temperature, and the flow part is at low temperature. In order to reduce the cold loss, the valve stem is often made very long, which is easy to deform and get stuck.
The separation of oxygen and nitrogen is realized by distillation. There must be rising vapor and falling liquid in the distillation process. In order to obtain oxygen and nitrogen products, the two-stage distillation process is realized in the upper and lower columns. Condensing evaporator is the link between upper tower and lower tower. It is used for the heat exchange between the reflux liquid oxygen at the bottom of the upper tower and the rising gas nitrogen at the top of the lower tower.DEAR Air separation equipment.When the purity of oxygen changes by 0.1%, the oxygen content in argon fraction will change by 0.8% ~ 1%. The argon content in argon fraction decreases with the increase of oxygen purity. The change of argon fraction directly affects the argon fraction entering the crude argon column. The higher the oxygen content in the argon fraction, the more the argon fraction entering the crude argon column. On the contrary, there will be less.The advantages of total immersion operation are: from the point of view of oxygen channel flow, the liquid oxygen surface is outside the plate unit, and the gas-liquid two-phase mixture with low density is inside the oxygen channel, which actually constitutes a liquid oxygen self circulation loop. When the heat load is constant, the higher the liquid oxygen level, the greater the liquid oxygen circulation rate in the oxygen channel.
