The Study On The Industry Application Of Co-rotating Twin-screw Extruder In Chlorosulfonated Polyethylene Production

The actual production capacity of chlorosulfonated Polyethylene(CSP)devolatilization production line in Calcium Carbide Factory of Jilin Petrochemical Co.affiliated to the PetroChina can not achieve the design standard due to the limited capacity of equipment,which restricts the competitive ability and development space of the production line.In order to resolve the problem,this thesis researches the industry application of co-rotating twin-screw extruder in the devolatilization and granulation production of CSP.Combined the numerical simulation with experiments,the effect of the screw elements and screw configuration of co-rotating twin-screw extruder on the devolatilization results of CSP was studied;the process flow and operating parameters of devolatilization production line of twin-screw extruder were optimized;the co-rotating twin-screw extruder was successfully applied to industry production of CSP through corresponding technical transform,which satisfied the requirements of quality stability and continuous long period production.At present,the equipment has been able to run a long period and continuously produce excellent quality products.The main achievements are as follows:(1)The flow field analysis results of kneading block structure of co-rotating twin-screw extruder showed that high pressure area of CSP melt lay in the advancing face of kneading block,and low pressure area lay in the back.Due to the pressure difference,the volatile components of CSP colloid formed volatile flash,which could remove the volatile components of the colloid quickly.The mixing process of kneading block structure was dominated by shear flow,and the elongational flow mainly concentrated in the area of the advancing face and the back of kneading screw where the shear rate was low.Among the 5 groups of kneading screw combination,KB1 group was easier to form a larger pressure difference,and elongational flow occupied a higher proportion in the flow field,therefore,a better devolatilization effect was achieved.(2)The experimental results showed that the co-rotating twin-screw extruder with reasonable combination of screws had a good devolatilization effect and could produce the high quality products of two brands(CSM30 and CSM40)of CSP rubber in the actual production.With the increasing of cylinder temperature,the volatile components in CSP were easier to be removed.However,with the increasing of screw speed,the residence time of colloid in the barrel was shortened and the volatile content in the product gradually increased.(3)The experimental results showed that pelletizing cooling method had a certain effect on the devolatilization.The water cooling method would have small amounts of water into colloid which would hinder the removal of volatile,while the wind cooling was beneficial to the devolatilization.(4)Through the appication of co-rotating twin-screw extruder and appropriate technical transformation,the production of CSP increased from 1000 tons/year to 2000 tons/year and the excellent ratio of products reached to 80%.While the consumption of CCl4 didn’t increase,making environmental emissions to meet the requirements.Not only improved the economic profit,but also enhanced the competitiveness and viability of the products.