Air separation plant is an important supporting facility for large-scale industrial enterprises, such as chemical industry, smelting industry, electronics industry and energy industry. Its operation condition is very important to the enterprise. In the actual production, the air separation plant is often be shut down by mistake due to many factors, such as instrument control incorrect interlocking, manual incorrect operation or network voltage fluctuation, which causes great losses to the enterprise. Here are a few preventive measures for incorrect shutdown.
1.Prevention of instrument and control system incorrect interlock: the common factors that causeinstrument and control system incorrect interlock include alternating magnetic field interference, detection component failure and unreasonable interlock parameter setting, etc.
a.In order to reduce the influence of alternating magnetic field on the signal of I & C system, when installing and using large electrical plant, welding machine, interphone and remote control device of plant, it should bekeptaway from the measuring elements of I & C, and regularly test the shielding and grounding performance of I & C cable.
b.Through the modification of the interlock, the interlock parameters should beset reasonably. The reliability of the instrument and control elements is enhanced, and the incorrect interlock shutdown caused by the failure of a single measuring element is avoided.
2.Prevention of manual misoperation: the common forms of manual misoperation include data input error, improper operation procedures in emergency state, misoperation of safety protection facilities, unconscious misoperation, etc. In order to prevent the occurrence of manual misoperation, the operation authority and scope shall be set at the key control points, and good operation habits shall be formed. Specifically, the programmed operation can be carried out through the preparation of post operation procedure card and process post emergency response card and other measures. In addition, it is necessary to carry out joint security system for post employees to strengthen their safety responsibility awareness.
3.Disturbance of networkvoltage fluctuation factor to plant: to minimize grid "sloshing point"for the interference of mechanical and electrical plant, the time relay with reset terminal can be adopted. In the moment of sloshing, when the speed of main motor has not decreased with the help of inertia, the voltage will return to normal, and the original main motor will be automatically reset and started.
In order to prevent the air separation plant from incorrect shutdown, it is necessary to start from many aspects such as the change of staff awareness, the improvement of skills, the refinement of plant management and the improvement of the stability of control system, so as to extend the continuous operation cycle of air separation plant and reduce the production and operation costs.
