Study On Continuous Dehydration Device Of Waste Oil

A certain amount of waste oil was produced in oil production and refining with high water content(usually higher than 10%),complex composition,strong emulsifying ability and stable properties.It was difficult to dehydrate from the waste oil,so it was impossible to achieve rapid and deep dehydration using conventional method such as gravity sedimentation,thermal sedimentation and centrifugal separation.As a major problem that puzzled the environmental protection and economic benefit of enterprises,it was urgent need to develop a new deep dehydration method and device of waste oil.The research at home and abroad shown the ultrasonic dehydration had high speed and efficiency,as ultrasonic wave had good conductivity in liquid.A combined method of heat treatment,chemical demulsification,ultrasonic treatment and sedimentation for dehydrate deeply of waste oil was adopted in this paper,and a set of corresponding continuous device was developed to shorten the processing time and improve the dehydration effect and efficiency.With this device the water content in waste oil was reduced to below 1%and met the requirements of refining,so the energy utilization and the economic benefit of refineries were improved,and the environmental pollution was reduced.Firstly,based on theoretical analysis and experiment,a small scale research was carried out to explore the influence of ultrasonic frequency,ultrasonic sound intensity,ultrasonic time,ultrasonic temperature,sedimentation time and sedimentation temperature on the dehydration effect.The water content in waste oil before and after dehydration was measured using distillation method,and the dehydration rate was calculated,so the suitable operating conditions were obtained.The operating conditions were the ultrasonic time 15 min?90 min,the sedimentation time 7 h as the oil sample height 0.029 m and the temperature 60??80?.Secondly,according to the operating conditions obtained from the small scale research the pilot experimental device and the core equipment processor structure were designed,and the equipments attached were designed or selected.Based on theoretical analysis to the dehydration process effective measures were taken to improve dehydration efficiency.The pilot processor was designed as integration of ultrasonic zone and sedimental zone,and the sedimental section was a flat structure.The length of the ultrasonic section was l_lmax=0.44 m,the length of the sedimental section was l₂=3.00 m,the width of the ultrasonic section was w₁=0.10 m,the width of the sedimental section was w₂=0.20 m,the height of the ultrasonic section was h₁=0.08 m and the height of the sedimetal section was h₂=0.04 m.The inlet section and the transition section were streamlined structure with a length of 0.10 m respectively.The adjustment range of the length ratio of the ultrasonic section to the sedimental section was1:14?1:33.Next,the pilot experiment scheme was planned according to the pilot device.Water experiment was planned to detect the tightness of the device and the performance of instruments and to measure the distribution of sound intensity within the processor.Simulative material experiment was planned to solve the problems of temperature control,pressure control and flow adjustment,etc.Actual material experiment was planned to explore the influence of sound intensity,the length ratio of the ultrasonic section to the sedimental section and the flux on the dehydration effect,and the suitable operating conditions would be determined.Finally,the industrial device and core equipment processor structure were designed preliminarily according to the pilot device.The industrial processor was designed as integration of ultrasonic zone and sedimental zone,and the sedimental section was a multi-layer flat structure.