The Design Of DCS Based On Metallocene Polyethylenes In Improvement Project

Metallocene polyolefin as a result of the unique structure of the legislation and good structured physical and mechanical properties, caused by the materials sector and of great concern to the industry, the rapid formation of a wave of metallocene polymers, this paper is background with the industrialization of the development of metallocene linear low density polyethylene (mLLDPE) the pilot production of Daqing Petrochemical Company, and is based on the mLLDPE device. The conventional process is controled mainly by the distributed control system (DCS).This paper mainly discusses the development process, advantages and disadvantages, and problems of DCS, and outlined the development status of distributed control system. Begenning from process characteristics of industrial fluidized bed polyethylene production, introduce the production process and process control of linear low density polyethylene, and research the technics calculate and control requirement, whith includes the process calculate, productivity calculate, productivity control, colophony formula, product sampling analysis, colophony property calculate and colophony property control. In the productive process controlling, the reactor press control, temperature control and constituents control are emphases researched. The DCS system of producting and management the metallocene polyole is been chosed and configured. Design the controlling loop, which included the hexane/ethylene flow ratio control, the hydrogen/ethylene flow ratio and the reactor ethylene partial pressure control. The controlling system of this paper designed has the good control effect from the system run carve.