Crude oil contains a lot of fine sand which has impact on the gathering and transportation system seriously.The equipments used for desanding are settlement pool,filter,centrifuges and hydrocyclone.However,lacks of them were also obvious.This paper combine the characteristics of centrifuge sand hydrocyclone,designs central feed-in dynamic hydrocyclone and the performance testing system of hydrocyclone,and does systematic experimental tests and theoretical analyses to hydrocyclone.Central feed-in dynamic hydrocyclone have several advantages such as having higher separation efficiency, having smaller decrease of pressure,having wider range of feed flux.Three experimental machines have three different impellers.This paper tests and analyses the impact of motor speed,split ratio,feed flux on pressure loss and separation efficiency of three experimental machines.The result shows that the higher motor speed,the higher separation efficiency and the smaller decrease of overflow pressure at small feed flux. The increase of split ratio can effectively improve the separation efficiency and enhance the decrease of pressure.The increase of feed flux has less effect on the separation efficiency,but the decrease of pressure are increasing.This paper compare the results and find that experimental machineⅢhave the highest separation efficiency,experimental machineⅡsecondly,experimental machineⅠhave the lowest separation efficiency,however the difference of the separation efficiency is unobvious. Based on the experimental results of pressure,it can be obtained that pressure performance of experimental machineⅠis best,experimental machineⅡsecondly,experimental machineⅢis last.The final result is that of experimental machineⅠhave the best performance.This paper simulate the flow field of new dynamic hydrocyclone and get the basic information of the flow field.It is shown by the simulation results that inner flow field is similar to normal hydrocyclone,but they have the bigger centrifugal strength,the tangential velocity of their inner is nearly 15m/s and the centrifugal force is 5～10 times bigger than the ordinary hydrocyclone.The relationship of pressure drop and size of impeller is show by simulation of impeller.The result can supply the guidance for optimizing performance of impeller.The central feed-in dynamic hydrocyclone has a favorable performance of pressure and separation.So it must have good prospects and the high value of commercial application in industrial process.

Crude oil contains a lot of fine sand which has impact on the gathering and transportation system seriously.The equipments used for desanding are settlement pool,filter,centrifuges and hydrocyclone.However,lacks of them were also obvious.This paper combine the characteristics of centrifuge sand hydrocyclone,designs central feed-in dynamic hydrocyclone and the performance testing system of hydrocyclone,and does systematic experimental tests and theoretical analyses to hydrocyclone.Central feed-in dynamic hydrocyclone have several advantages such as having higher separation efficiency, having smaller decrease of pressure,having wider range of feed flux.Three experimental machines have three different impellers.This paper tests and analyses the impact of motor speed,split ratio,feed flux on pressure loss and separation efficiency of three experimental machines.The result shows that the higher motor speed,the higher separation efficiency and the smaller decrease of overflow pressure at small feed flux. The increase of split ratio can effectively improve the separation efficiency and enhance the decrease of pressure.The increase of feed flux has less effect on the separation efficiency,but the decrease of pressure are increasing.This paper compare the results and find that experimental machineⅢhave the highest separation efficiency,experimental machineⅡsecondly,experimental machineⅠhave the lowest separation efficiency,however the difference of the separation efficiency is unobvious. Based on the experimental results of pressure,it can be obtained that pressure performance of experimental machineⅠis best,experimental machineⅡsecondly,experimental machineⅢis last.The final result is that of experimental machineⅠhave the best performance.This paper simulate the flow field of new dynamic hydrocyclone and get the basic information of the flow field.It is shown by the simulation results that inner flow field is similar to normal hydrocyclone,but they have the bigger centrifugal strength,the tangential velocity of their inner is nearly 15m/s and the centrifugal force is 5～10 times bigger than the ordinary hydrocyclone.The relationship of pressure drop and size of impeller is show by simulation of impeller.The result can supply the guidance for optimizing performance of impeller.The central feed-in dynamic hydrocyclone has a favorable performance of pressure and separation.So it must have good prospects and the high value of commercial application in industrial process.

Crude oil contains a lot of fine sand which has damaged to the gathering and transportation system seriously. Static hydrocyclone being used now in oil field is inefficiency and fluctuation of oil flow also affects its efficiency.Confront with this practical problem, this paper adopts the most reasonable feed methord according to pressure distribution of centrifuge force field to design central feed dynamic hydrocyclone, combining the characteristics of centrifuge sand hydrocyclone. This paper makes lots of experiments to optimize pressure performance and separation performance through changing structural parameter and determines final industrial machine which has the most reasonable structural parameter. This paper simulates the flow field of the final industrial machine through CFD and analyzes flow field distribution in detail.This paper makes lots of experiments to optimize pressure performance though changing only one structural parameter, and finds that reducing height of impellers, reducing diameter of impellers, increasing diameter of underflow outlet, increasing diameter of overflow pipe, increasing diameter of overflow pipe outlet and increasing inlet deflection angle of impeller can improve pressure performance effectively.This paper makes lots of experiments to optimize separation performance though changing only one structural parameter, and finds that increasing diameter of impeller, reducing diameter of overflow pipe outlet and adding a cap to overflow pipe can improve pressure performance effectively.This paper determines structural parameter of final industrial machine after structural parameter optimization experiments. Final industrial machine has good pressure and separation performance. When flow is between 20m3/h and 40m3/h and the rotary frequency of impeller is 25HZ, underflow can reflux to entry flow. When flow is between 20m3/h and 40m3/h and the rotary frequency of impeller is between 25HZ and 40HZ, separation efficiency is higher than 93% and maximum to 98%.This paper simulates the flow field of the final industrial machine and analyzes flow field distribution in details. This paper optimizes structural parameter of impeller and finds that increasing inlet deflection angle from 16 degree to 90 degree can improve pressure performance. The central feed dynamic hydrocyclone has a favorable pressure and separation performance, and it will have a good prospect in industrial application.