PVC Manufacture Batch Process Control

Polyvinyl chloride (PVC) is one of most wide useful synthesize materials in our country, having the good development future. Now PVC manufacturers are reforming the technique, extending the production scale. At the same time, they also request the higher level of the automation in the process.PVC is made by batch process mode. Batch process has flexible characteristic. It is beneficial to the enterprise satisfying the demand of market competition, adjusting the production structure, announcing new products, and improving product quantity. It is widely applied to the products such as chemical industry, drug manufacturer, food manufacturer, etc. Along with the development of control technical, many kind of advanced technique gets the application in batch process control, such as DCS, PLC, etc. However, for long time, only regulatory control has been implemented in PVC production, aiming at some particular craft process, equipments and products, can't satisfy the flexible request in system. In this paper, we analyzed the request of the control system, given a PVC plant's physics model, process model and procedural control model based on ISA SP88 standard. Broken up complex concepts into smaller elements in order to reduce complexity and promote reusability. Constructed a control system for PVC manufacture using YOKOGAWA co.'s CENTUM CS3000 DCS.Recipe management: The recipe not only has operation parameters, but also has procedurals and equipments' request and other information.Process management: Transfer the master recipe to control recipe, manage the resource of equipment, receive the command of production plan and schedule, collect the information of batch and send to the plant management system.Unit Supervision: set a unit as a supervise and control object, not generally as a control loop, collect the information of unit and hand over to process management.