Structure Design And Experimental Research On Mixed Flow Hydrocyclone For Produced Water

At present,treatment for produced water mainly use oil removal tank on account of gravity.Oil removal tank relying on gravity which make oil and water separate layer in a certain resident time.However,it occupy large area and have low efficiency as well as unable to handle emulsified oil.With the volume of produced water increasing by years,the equipment based on gravity cannot adopt to demand of oil field development.Compared to oil removal tank,hydrocyclone is a centrifugal separator which can produce hundreds even thousands times gravity.Hydrocyclone,due to its compact structure and high efficiency,is gradually generalized to the field of oil-water separation.In this paper,based on some researches of hydrocyclone,we designed a mixed flow hydrocyclone with designing flow rate 1m3/h.First,with the assistance of numerical simulation,we studied the influence of flow rate and flow split on separation efficiency.Then,we analysis flow pattern of time average velocity field as well as foundamental frequency of tangential velocity.In order to verify accuracy of numerical simulation on distribution of hydrocyclone,we manufactured a device which can test flow field in the mixed flow hydrocyclone which use Laser doppler particle dynamic analyzer to detect velocity field and turbulence intensity under different operation parameter.The tendency of tangential velocity increase first and decrease later along the radial position,and axial velocity present the distribution that the upward flow around axis and the downstream flow around wall.Besides,the tangential velocity frequency decreases first and increases later along the radial position,which shows "saddle" distribution.In addition,in order to measure oil-water separation efficiency under different operation parameter,we manufactured test device for mixed flow hydrocyclone.The test investigates influence on oil-water separation efficiency with different flow rate,flow split and oil concentration.The consequence demonstrates that the separation performance achieve the opitimum with 1m3/h flow rate,10000ppm concentration and 9%flow split.Finally,we designed an engineering test prototype with 30m3/h flow rate based on certain design criterion.In this paper,the research of mixed flow hydrocyclone is developed in terms of "principle of structure design ? research on flow field ?test on oil-water separation performance",which reveals the relationship between the characteristic of flow field pattern and separation efficiency.The laboratory experiment of mixed flow hydrocyclone provides reference frame for development of hydrocyclone and technical support to design of field engineering prototype.