During the operation of the fractional distillation tower, frequent pressure fluctuations can disrupt the gas-liquid equilibrium within the tower, directly affecting the purity of oxygen and nitrogen products. It is also prone to deteriorate the operating conditions of the distillation tower, impacting the safe operation of the equipment. To address the issue of fluctuating pressure, the following adjustment measures are formulated in conjunction with on-site operating specifications.
First, stabilize the intake air source. Fluctuations in intake air volume are the primary cause of pressure fluctuations. Closely monitor the outlet pressure of the air compressor and the air flow into the tower, and prohibit significant increases or decreases in the load of the air compressor. Maintain stable intake pressure and flow, reduce system pressure disturbances at the source, and prevent tower pressure oscillations caused by sudden changes in intake air volume.
Next, optimize the reflux and product withdrawal volume. Strictly control the opening of the liquid nitrogen and waste nitrogen reflux valves, following the principle of small and slow adjustments, and prohibit abruptly opening or closing the valves. When the tower pressure is high, appropriately open the waste nitrogen vent valve and increase the product gas output to release excess gas phase inside the tower; when the tower pressure is low, close the vent valve to reduce product withdrawal and balance the gas phase load inside the tower.
Then balance the system cooling capacity. Check the operating parameters of the expander. Fluctuations in cooling capacity can lead to unstable heat exchange in the condensation evaporator, indirectly causing pressure fluctuations in the tower. Fine-tune the expander speed according to the operating conditions to ensure stable supply and demand of cooling capacity, maintain normal heat exchange in the main condenser, and eliminate pressure fluctuations caused by imbalance between cold and heat.
Finally, troubleshoot instrument and equipment malfunctions. Check whether the pressure regulating valve and self-operated pressure regulating valve are stuck, and calibrate the on-site pressure detection instruments. If the valve malfunctions or the instrument data is distorted, switch to manual operation in a timely manner and contact maintenance personnel for inspection and repair. During daily operation, adhere to smooth adjustments, avoid sudden changes in operating conditions, quickly restore the pressure stability of the distillation tower, and ensure continuous and stable operation of the device.
