Control systems, redundant, chemical plant

Computer-controlled chemical plants are becoming the rule rather than the exception. As a result, it is possible to measure more variables and get more process information than ever, and chemical plants can be made inherently safer than ever before. However, it must be kept in mind that instruments and control components will fail. It is not a question of if they will fail, but when they will fail, and what the consequences will be. Therefore, the question of redundancy must be thoroughly considered. The system must be designed so that when failure occurs the plant is still safe. 

The process unit has many loss control features. The plant has a diesel emergency power generator with an emergency cooling system. The plant is also under computer control with emergency shutdown based on redundant inputs. Vacuum is always broken with nitrogen. The process has complete, written, and up-to-date operating instructions. A reactive chemicals review was completed recently. The process has several interlocks to prevent polymerization. 

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