Experiments On The Separation Of The Hydrocyclones For The Online Solid Removel Of The Delayed Coking Wax Oil And Diesel Oil

Based on the problem of coke powder(catalyst powder)in coking products of delayed coking unit,a hydrocyclone technology for the on-line solid removel of coking wax oil and diesel oil was developed.This make sure that the coking wax oil can enter the residue hydrogenation smoothly and the coking wax oil unit realizes long-time operation.In this paper,the separation performance of hydrocyclone for on-line solid removel of coking wax oil and diesel oil under different structural parameters and operating parameters was studied using experimental methods.The better structure and suitable operating conditions of hydrocyclone were obtained.Moreover,the small-scale test of the separation performance of hydrocyclone.was carried out.These results can provide guidance for the industrial scheme design of hydrocyclone for on-line solid removel of coking wax oil and diesel oil.Firstly,the physical properties of coking wax oil and diesel oil,such as viscosity,density,four components,solid content and solid particle size,were analyzed.The results showed that coking wax oil and diesel oil had good properties,low solid content,relatively large particle size,and the viscosity and density decreased with the increase of temperature,which indicated that it was feasible to remove solid particles from coking wax oil and diesel oil by hydrocyclone under high temperature condition.Secondly,cold model experiments were carried out on the hydrocyclone for the solid removel of coking wax oil and diesel.The effects of structural parameters(overflow diameter,inlet type)and operating parameters(feed flow rate,concentration,underflow rate,viscosity)on the separation performance of the hydrocyclone were analyzed,and the separation performance prediction model of A75-S Hydrocyclone was established.The experimental results show that compared with DN50 type cyclones and DN75 type cyclones with other structures higher separation efficiency and smaller separation pressure drop of the A75-S axial-flow hydrocyclone were obtained.The influence of operation parameters on the separation performance of A75-S axial-flow hydrocyclone is as follows:feed flow>underflow rate>feed concentration.When the feed flow rate is 4m~3/h,the bottom flow rate is15%,the feed concentration is 0.40%,the separation efficiency of the A75-S axial flow cyclone is 96.2%,and the pressure drop is about 0.2MPa.These results indicate that it is feasible to use A75-S axial-flow hydrocyclone to realize the solid removel of the delayed coking wax oil and diesel oil.Finally,based on the on-site process conditions and medium properties of coking wax oil,the laboratory test of separation performance of hydrocyclone for the solid removel of coking wax oil was carried out to optimize the operation parameters and determine the optimal separation conditions.The results show that when the temperature is above 70℃(mainly considering the influence of the viscosity of coking wax oil),it is feasible to remove the solid from coking wax oil by using swirl separation technology.The separation efficiency is over55%and the pressure drop is less than 0.2MPa.