The dynamic hydrocyclone was a new-style and high-efficiency separation equipment.was based on the technology of hydrocyclone which was more proven. As a separation equipment, better separation performance of dynamic hydrocyclone in continuous working was required. The unsuitable choose of physical property parameter, structural parameter and will have effect on separation performance. To obtain perfect separation performance, the study on the relation of each influential factor and effect of each factor on performance was necessary.In this paper laboratory and field experiment were used to the problems. First test equipment of dynamic hydrocyclone for laboratory experiment was established. Using the method of experiment and theoretical analysis, experimental study of separation principle and separation performance was carried out. Systemic analysis of effect of physical property parameter, such as diameter of overflow mouth, ratio of length and diameter, flow rate of inlet, split ratio, rotate speed of motor, temperature and concentration of water, on separation performance was carried out too.From experimental study, the logical progression of factors influencing dewatering performance was acquired. Concentration of water was the most important one in these factors, and from higher to lower they were concentration of water, rotate speed of motor, split ratio and temperature in turn . Optimum value and optimum interval were determined. The optimum concentration of water,temperature,rotate speed and split ratio were 80% ,50℃, 10 m~3/h, 1050r/min and 10% respectively. The optimum interval were respectively 40℃～60℃, 10m3/h–13m~3/h, 900r/min～1050r/min and 8%～12%. Oil dewatering system was established and experiment was carried out, and will lay the foundation of application of dynamic hydrocyclone on on oilfield.
Post about "Separation performance"
Columnar gas and liquid separator with current regulator is new highly effective centrifugal separation equipment developed on the base of convention columnar gas and liquid separator.is studied the feasibility of the application of the gas and liquid separator with current regulator in the oil-gas field picks fluid processing. The columnar gas fluid cyclone has a small volume but a big handling ability, can separate the small volume air bubble effectively and quickly with a stable separation effect and so on, has a wide application prospect.The main teseatch content of this article is to definite eddy separation plan, to examine the separation effect of gas, to analyze the effect and the characteristic of the gas and liquid separator with current regulator according to the oil-gas field the characteristic.Using the mixed model to carry on processing to the multiphase flow, the distributed rules and the stalling characteristic of gas and liquid flow field can be known. is studied a conventional columnar gas liduid separator and did computation simulation and structure optimization design. Using the CFD method and hydromechanics analysis software FLUENT, I conducted the research and the analysis to the interior flow field of the columnar gas liquid separator. Through the simulation analysis, the structure improvement has been done, obtained a new reasonable columnar eddy with current regulator separator model.According to new structural gas-liquid separators obtained from the simulation analysis, a test prototype is manufactured. By the experimental study on the new structural gas-liquid separators, it further proves the good effect of the new prototypes for processing gas liquid mixture, and it also further proves that optimal design of hydrocyclones is feasible by using simulation. The effects of flow rate, split ratio, as well as dimension of steady flow unit and position of steady flow unit on the separation efficiency is researched. The existing problems of new prototypes in the experiments is analysised, and the new prototypes are improved on this basis.This paper provides a certain theoretical basis for further studying separation mechanism and structural optimization design gas-liquid separators, and it can provide reference for worksite application.
Most old oil-fields have entered into the mid or late period of development in the world, the content of water has reached a quite high level, andwill inevitably increase exploitation cost and water treatment cost, increase pressure for environment processing, and bring huge negative influence for economy and environment. In order to re-exploit the old oil-fields which are about to be shut down because the cost reaches the limit of economical exploitation, a new technology has been proposed. Through the application of this technology the mixture of oil water and sand is separated at underground, oil-rich liquid together with sand is lifted to the ground; the clean water is injected back directly through special pipe to keep pressure of the stratum.This article is based on the design idea above, and we combine with theoretical analysis, simulate underground conditions in the laboratory to carry out multi- separation on the basis of optimizing the monomer structure of . We have designed different separation according separation request to research the influencing factors of natural parameter and operating parameter to the system separation performance so as to optimize the partial design parameter and to achieve reasonable satisfaction effect when the holistic machine runs. Finally, -pressure match test research has been done for the smoothly mixing of three fluids of different flow and different pressure.Through systematical and comprehensive experimental study, we have optimized the optimum structure of monomer, designed separation system for each technological requirement and determined the reasonable operating parameters for each flow; we have also solved the transportation problem of oil and sand, provided reference for choosing system model in the future.
In recent years,nanofiltration（NF） membranes were paid attention by the researchers in separation membrane field,because of their low operation pressure,nanometer porous structure and unique separation functions for aqueous solutions containing solvents with hundreds of molecular weights and multivalent ions.In this work,PES,PI and PES/PINF membranes were prepared by immersion precipitation phase inversion technique using acetone,propanols and PVP as additives, respectively.The effect of composition of the casting solutions and process conditions on the performances of NF membranes was investigated. was found that,with the increase of polymer concentration,the rejection to PEG1000 increased,but both the porosity and flux of the membranes decreased.Adding additives can weaken the thermodynamic stability of the casting solution,and induce the process of phase separation to be easy.The maximum content of micromolecular nonsolvent additives in the casting solution was obtained by the cloudy point testing, was found that the ability of leading to turbidity of the micromolecular nonsolvent additives decreased as follows:iso-propanol＞n-propanol＞acetone.According the results of the separation experiments for PEG1000, was found that the flux of the membranes decreased and the rejection increased by adding acetone in casting solution.However,the result was opposite when the propanols were taken as additives.When the approaching ratio of propanols was over 0.8,there were different trends for the effect of n-propanol and iso-propanol on the flux of the membranes:the flux of the membranes prepared with adding n-propanol decreased but the flux kept increasing when adding iso-propanol.When PVP was added into the casting solution,the case became complicated.Adding PVP in the casting solution not only weakened the stability of casting solution,but also changed the rule of effects of propanols on the separation performance:the flux of the membranes with n-propanol as additives kept increasing when the approaching ratio of propanols was over 0.8.On the contrary,the flux with iso-propaaol decreased.By studying the difference of solubility parameters between two components in the casting system,it was found that there was relation between the effect of additives on membrane performance and the interaction between components in the casting system.The influence of evaporation time and coagulation temperature on the performance of NF membrane is also examined.The results showed that both increases of evaporation time and decreases of coagulation temperature made the flux decreased and the rejection increased.The influence of ambient temperature on the separation performance was firstly investigated in this dissertation.The results showed that increasing ambient temperature enhanced the rejection greatly.The effect of ambient temperature couldn’t be ignored.On the basis of the above results,the NF membranes were prepared by changing the mass ratio of PES to PI.It was found that with the increase of PES content,the flux of alloy NF membrane firstly increased and then decreased,but the trend of the rejection was opposite. The separation performance of the membranes with 7%of PES content was better.The alloy NF membrane was used for the experiment of separating and purifying benzylpenicillin sodium.It showed that the self-made alloy NF membrane had a good separating performance for benzylpenicillin sodium.The average rejection was over 40%.The flux of the membrane increased with the increases of operating pressure and the rejection decreased.When the concentration of the feed was 20g·L-1,the dimmer of benzylpenicillin sodium formed on the surface of the membrane due to concentration polarization,which made the rejection increased rapidly under 0.8MPa.When the concentration of the feed increased,the flux decreased but the rejection increased.Compared with other NF membranes reported in some articles,the performance of the alloy NF membranes prepared by blending was excellent.The results of this dissertation provide theoretical foundation for optimization of NF membrane preparation process.It is proved that the control of average pore size of NF membrane achieving by changing the compatibility of polymers is feasible.
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.However,lacks of them were also obvious.This paper combine the characteristics of centrifuge sand ,designs central feed-in dynamic 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, can be obtained that 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 information of the flow field. 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 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.However,lacks of them were also obvious.This paper combine the characteristics of centrifuge sand ,designs central feed-in dynamic 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, can be obtained that 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 information of the flow field. 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.
The dynamic hydrocyclone which developed from hydrocyclone was a promoting and high-efficiency separation equipment. With the in-depth study, the structural problems of dynamic hydrocyclone appeared. Promotion and application ofwere constrained. Moreover, the study on flow field of dynamic hydrocyclone was not consummate. In the past, the optimization design of dynamic hydrocyclone always depended on experience. With the rapid development of the on flow field analysis, provided strong tool for and design.In this paper, the present development and appliance of dynamic hydrocyclone were introduced. The main structure problems leading to vibration and bad bearing lubrication were analyzed. Solutions were proposed and improvement design on dynamic hydrocyclone was completed. was concluded from the vibration performance and oil dewatering test that the improved structure was reasonable. Variation rules of pressure characteristics and separation efficiency under different operating parameters were obtained too.Based on algebraic slip model (ASM) of Euler-Euler method, RNG k-εturbulence model and Single Reference Frame (SRF), the mathematical model of two-phase flow field in dynamic hydrocyclone was established. Numerical simulation was carried out by using CFD software FLUENT with control volume method and SIMPLE arithmetic method. The rules of velocity distribution, pressure distribution and oil-water distribution were obtained. The comparison results of simulation results and experimental measured data verified that the mathematical model and numerical simulation method were reasonable.Using numerical simulation method, optimization was done to the rotating fence. The results of simulation indicated that under the certain flow area, the rotating fence with straight vanes of 75mm can best balance the stationarity of the flow field, pressure loss, liquid vortex intensity and separation performance. The rotating fence with spiral vanes of angle of 60°can form enough intensityof lquid vortex without excessive pressure loss which is uperior to other structure.
To enhance the separation performance of existing double volute cyclone tube used in the natural gas purification, structural improvements was carried out. By studying the gas-solid and gas-liquid separation performance of different structure cyclone tubes to get new double volute cyclone tube,which has the best separation performance. And also measure the air flow characteristics of different structurecyclone tubes. The results showed that the existing double volute cyclone tube was low separation efficiency, and the short-circuit flow near the pipe opening region up to 76%; The vortex core near the dust exhaustor have severe torsion; Core pipe had countercurrent type slots in sidewall can improve the separation efficiency of cyclone tube; The underneath opening diameter of core pipe had countercurrent type slots in sidewall has a threshold,d=48mm; Above or below this threshold, the separation efficiency of cyclone tube would decrease; When the separation space height h = 100mm, the cyclone separation efficiency reached the highest value, 0.92, higher than reference cyclone tube by 7%, the resistance coefficient is 43, higher than the reference cyclone tube by 16%, the separation efficiency of the liquid drop group with the median size 59.04μm、38.24μm、30.69μm is 0.93、0.88、0.77,and is the best cyclone tube,we namednew double volute cyclone tube. The flow field tests showed that the slots in sidewall of the new double volute cyclone tube can be effectively reduced 92% of the short-circuit flow, short-circuit flow can be reduced to 6.14% of the total inlet flow; The vortex core torsion near the dust exhaustor disappeared.
As a developmental research with great prospect, membrane separation technology has been widely applied in the modern industry. And as known to all, pervaporation is a new type of membrane separation technology which has many advantages over other techs in the separation of liquid mixtures, such as high efficiency, low energy consuming, simple operation process, etc. Particularly,is very suitable for the separation of homogenous mixtures such as closing-boiling and isomeric mixtures, which are usually difficult or impossible to be separated effectively. has been generally regarded as a very nice and comprehensive alcohol-prior penetration membrane material, but unfortunately the material just has a relatively low strength is also very poor; consequently, many scholars have tried their best to improve its strength and separation ability. On the other hand, is a kind of strength supplement, and has an ideal property of hydrophilicity because of the hydroxyl groups absorbed on the surface, which leads to a difficult diffusion when mixed with organic phase and meanwhile affects its application prospect, so it is necessary to enhance its compatibility in the organic phase via surface hydrophobic modification and thus extend is application field.In this paper, fumed silica was modified to possess hydrophobic property by organic wet method taking hexamethyldisiazane (HMDZ, modifier) and dimethyl- diethoxysilane (co-modifier) as modifiers. The appraisal of modification effect was investigated by measuring the surface hydroxyl groups. The influences of different organic solvents for the modification results were respectively studied, and particularly the impacts of temperature and reaction time when used toluene as solvent were discussed, and a preferable preparation process condition was obtained by using toluene as solvent, at 110℃for 90 min.The evaluation of the various surface modifications of silicon was finally characterized by infrared spectrum analysis and TEM. It was found that a certain amount of polymer had been attached to the surface of the fumed silica, which conversely reduced the original content of SiO2. And settlement experiment of water as solvent showed the modified fumed silica possessed high hydrophobic property.The current /PET s were prepared by filling membrane with fumed silica and modified fumed silica on PET membrane. The tensile strength, physical morphology, molecule structure and thermal resistant performance of the as-prepared s were investigated by WSM-5KN. TGA. FT-IR and SEM. And further the effects of feed temperature, feed concentration, vacuum, content of modified fumed silica on the pervaporation performance of ethanol/water solutions were also examined.It was shown from the results that the thermal resistant performance of the modified membrane was significantly improved and it increased as the modified fumed silica increasing. Its tensile-strength was increased from 1.5 MPa to 7.4 MPa compared with pure PDMS. And the SEM results indicated that the modified hydrophobic fumed silica could be better distributed in the PDMS membrane than ordinary silica.It could be obtained from the pervaporation results that the permeation flux of the as-prepared membrane was in direct ratio with the gradual increase of feed concentration, feed temperature and vacuum, while the separation factor appeared to increase with the raising of vacuum and the feed concentration at first and then declined as well as feed temperature, and further the related relationship between component flux and temperature could be explained by Arrhenius equation. Otherwise the peak value of the membrane separation factor seemed to constantly appear in advance.
Crude oil contains a lot of fine sand which has damaged to the gathering and transportation system seriously. Staticbeing 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 , combining the characteristics of centrifuge sand hydrocyclone. This paper makes lots of experiments to optimize 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 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 will have a good prospect in industrial application.