Suction Filter is a new type of filtration and separation machine. Its features are simple structure, high automation, no interruption of downstream flow during flushing, continuous flushing and high efficiency.can be used in industry, irrigation and municipalities.This thesis is concentrated on structural design, s study and analysis of flow field, the overall structure of the Suction Filter is figured out.The Suction Filter includes filtration part and transmission part. The filtration part includes pressure vessel, filter cylinder, . Required by chemical process, there are large openings on the shell of the pressure vessel, so is important to analyze the stress intensity and deformation of the pressure vessel with ANSYS and method of analysis design. The echelon-shaped wire of filter cylinder is easy to back washing, but has complicated structure, so using ANSYS to analyze .The of Suction Filter has been studied in this thesis. Base on the Darcy classical formula about filtration, pressure decline produced by filtrating medium and solid particle during filtration is estimated. According the sedimentation theory, the ability for carrying solid particles is also studied when back washing. The result is compared with The CFD simulation by CFX software.Suction scanner is an important part of . By using CFX, simulates the flow field of the medium inside the Suction Filter, then analyses the distribution of the pressure and velocity. As the several changing of structure form, studies the variety of the flow field in the , then optimize the design of the .
General Chemical Archive
Papers through a lot of research, on a toxic and harmful substances in the production, storage and transport accidents in the course of the leakage of the status quo as well as poisonous and harmful substances in the production, storage and transport accidents in the course of the leakage on the purpose and significance. At home and abroad poisonous gas or steam-proliferation studies summarized by domestic and foreign poisonous gas or steam leakage model for the spread of contrast, select the Gaussian model as a simulation software model, and applied analysis of the consequences of the accident.In this paper, industrial chemicals were introduced, and its harm to the human body was studied. In this paper, 2001-2006, the domestic accident statistics, that the explosion, poisoning and suffocation are frequent incidents in chemical plants demonstrated in the spread of toxic and harmful substances on the simulation of chemical safety is of far-reaching significance. And through direct leaked to the cause of the accident concluded, summing up the 10 categories often leaked and four kinds of accidents caused by various reasons.Based on the complexity of these models, the amount of computation, this combination oftechnology has been developed based on Visual Basic6.0 the spread of poison simulation software, a decrease of manual calculation. Finally, the software used in the preparation of the case, the liquid chlorine leak through the simulation, and further to liquid chlorine at different atmospheric stability, the release of the source and a high degree of proliferation of surface roughness when summing up the situation was analyzed, and concluded: For the continuous leakage , The leakage rate in certain circumstances, the greater the height of the release of the source and endanger regional smaller atmosphere more unstable, endangering regional smaller regional wind speed greater harm smaller endanger the region mainly in the release of the source The wind direction, wind direction of the harm than perpendicular to the direction of the wind against a range of more than in the same region.
Stirred tanks are typical process equipment and are widely used in. When the fluid in stirred tanks is turbulent, the fluid can mix well rapidly. But in the cases that the fluid viscosity is large or the fluid material is sensitive to shear force, the fluid in stirred tanks has to be in laminar. In these cases there are isolated mixing regions (IMRs) which are the worst obstacle to mixing existing in stirred tanks. With the rapid development of chaotic and nonlinear theories, can be utilized to destroy the IMRs and improve the mixing effect.According to the theory, aperiodic flow perturbations can be used to destroy the IMRs. So the blades of the 6-blade turbine were upper and lower dislocated respectively to generate the aperiodic flow field. The effect of the dislocated baldes on destroying the IMRs was investigated both experimentally and computationally. The main research contents and results are as followings.Firstly, Multi-reference frame(MRF) method was used for simulating the flow field of the standard 6-blade turbine. The positions of the IMRs were accord with the foreign experimental results. So the simulation method is feasible. Through the reliable FLUENT simulation method the velocity fields of different blades can be obtained. The results show that mixing effect of the dislocated blades are better than the standard blades and the improvements of the field depend on the dislocated scope and Re. The lager the blades dislocated, the better the mixing effect is. On the basis of the steady velocity field within the stirred tanks, the simulation of unsteady flow field were carried out by adding tracer. The results show that there are two IMRs whose tracer concentration are low in the standard 6-blade turbine stirred tank, however there aren’t IMRs existing in the dislocated 6-blade stirred tanks. So the dislocated blades can destroy the isolated mixing regions.The acid-base neutralization experiments were used to validate the mixing effect on the basis of the former simulations. The experimental results validate the simulation conclusions. There are two IMRs existing above and below the impeller respectively. The dislocated blades can destroy the IMRs and the mixing effect are better. But whether the dislocated blades can destroy the IMRs completely depend on the impeller speed and the dislocated scope of blade.
Under the condition of the society who focuses on energy saving,the technology of absorption cycle has been greatly paid attention in recent years.GAX absorption cycle is one of the new absorption cycle with high efficiency.Absorber and evaporator of GAX absorption cycle are important elements of the energy coupling equipment,which play a key role on a total performance of the refrigeration or heat pump system.This paper studies on the crucial subjects:news,simulation of the absorption cycle and performance anylasis of the of GAX absorption cycle.By summarizing and analysis the recent research on the s of the absorption cycle,the paper introduced ionic liquid as a new working fluid.The Ionic Liquid has several special characteristic used in absorption cycle as environmentally benign medium,such as excellent solubility,high boiling point and low vapor pressure.The heat capacities of ionic liquids [Emim]BF4 and its aqueous solution were measured by Calvet microcalorimeter.The relationship between the heat capacity and its temperature as well as concentration has also been built.Set up the thermal property models of the ionic liquid and the calculation program of the absorption heat transforme（AHT）cycle based on the models.The performance of the absorption heat transformer with the working pair TFE-[Bmim]Br was studied.Compared with the H2O-LiBr AHT system, the TFE-[BMIm]Br AHT cycle could be used in a broad working condition and has high temperature output.Taking the technologies of and as the background,a device has been set up which contains a process inside and a forced outside.This device is 3000mm high and with a heat-transfer-length of 2000mm long.The diameter of the falling film is 16mm,and the thick of the is 1mm.The device could bear the pressure of 1MPa,and contains a temperature data acquisition system.Carried out the cold model experiment and got the different heat-transfer performances of the double-film device with different water flow rates. On-site experimental operation shows that the proposed system is stable, the relationship of the simulation data and experiment data has a certain consistency that the average deviation is lower than 2%.According to the simulation result,there is a 25%performance improvement compared with the ordinary falling film process.Based on the transfer property of the double-film device got from the cold model experiment,the hot model experiment was carried out and simulated.A hot model experiment was carried out at the condition:flow of the falling film,1.50 L·min-1;inlet temperature of the falling film,21.5℃;inlet temperature of the forced climbing film,21.5℃;pressure of the NH3, 0.2MPa.A qualitative temperature distribution curve was observed.A model for the coupling of falling film absorption process inside and forced climbing film heat-mass-transfer process was presented based on the properties of the ammonia solution and the heat-transfer model of the cold model experiment.The author simulated the double-film process with the working pair of NH3-H2O,and analyzed the heat and mass changes inside of the system.These elements were analyzed:absorption heat change,dQx; cooling load change,dQc;flow of the NH3 absorbed by H2O,dqm; concentration of NH3 in the vapor phase,ye.This paper offers the data and provides reference for the absorption cycle with the working pairs of[Emim]BF4-H2O or TFE-[Bmim]Br.The technique of double-film,the double-film device and the double-film model coupling the heat and mass transfor set up a foundation for the following experiment and the principle analysis in the research area of the .
Finite Element Analysis and Stress Evaluation of a Heat Exchanger with Tilted Conical Shell and Tubes
In this thesis, a three dimensional finite element model of a heat exchanger withand tubes is built by ANSYS software, and then the finite element analysis for the equipment are studied by the model.In this thesis, research works are done as follows.First, geometric model and finite element analysis model are built, which based on that dimensions and processing of the equipment are studied, and its complexity considered;Secondly, with according to processing condition, conduction heat is calculated for the entire heat exchanger and the whole in the equipment is obtained;Thirdly, the strength of the heat exchanger is analyzed by the finite element model under various of combined loads from pressure in the tube, shell and temperature changing, and then stress intensity under the various of cases and location are gotton; meanwhile, the loading condition for operating, emergency and caustic washing conditions are built. Fourthly, with according to the JB4732–1995《Steel pressure vessels—-Design by analysis》, stresses in results of finite element analysis are assessed; Finally, the life in fatigue for the heat exchanger is verified and checked.The analysis results show that the whole model and its elements of the heat exchanger meet the strength requirement, and also do fatigue strength within life of design. So the design of the equipment is safe.This analysis results can be used as useful reference data to design this kind of heat exchanger in China.
The pervaporation technology is one of the most promising separation methods in the future.The diffusion of penetrant in the membranes is the key process in membrane separation technology,which greatly affects the separation performance of membranes.So the study of diffusion is very important for the development of membrane separation technology.In this thesis,twelve kinds of(PI)membranes with different structures were prepared via condensation polymerization by three kinds of dianhydrides and four kinds of diamines.The dynamic of steam permeated in different PI membranes at the temperature of 298K were measured.The relationships between the adsorption property and the PI membrane structure and the diffusion forms were discussed by using the calculated .The dynamic of different solvents(methanol,ethanol,and isopropanol)at different temperatures were measured.The influences of these diamine,dianhydride chemical structures,different solvents and different adsorption temperature in the membrane adsorption property were discussed.The experiment results show that the process of diffusion of penetrant in the membranes was divided to two segments,which wereⅠandⅡ. The rate of diffusion in sectⅠwas lower than that in sectⅡ.The forms of diffusion of penetrant in the membranes were divided as four kinds according to the value of .They are:Exceeded diffusion as 0＜d_w＜2,Fick diffusion as d_w=2,Anomalous diffusion when d_w＞2 and CaseⅡdiffusion when d_w→∞.The influence of these diamine,dianhydride chemical structures on the membrane absorption characteristics was most.The PI membranes with big density,low d-spacing and FFV,low chain packing density and weak chain mobility have low diffusing ratio of penetrant in them.the diffusion of water in PI membrane obey Fick’s law,while the diffusion of alcohol in the PI membranes did not,but showed anomalous diffusion phenomena.The order of diffusing rate of different penetrants in PI membranes were water＞methanol＞ethanol＞isopropanol.Temperature was an other factor influencing the diffusing rate.When the temperature was high, the of penetrant diffusing in the membranes was low,what indicating the high diffusing rate.
Some contents are discussed for the purpose of preparation of integrated andin pervaporation with compact surface.The polyamide membranes were prepared by using a novel ODPB-BAPP condensation polymer as the membrane material; N-methyl pyrrolidone was selected as the major solvent depending on the data of both solubility parameter and casting solution viscosity; The volatile solvents, such as tetrahydrofuan, acetone and ether, were added respectively in the coating solution as the co-solvents.Discuss their infection on casting solution viscosity, , phase separation times, gelation rate and structure and performance of membranes;Water,ethanol, propanol, isopropanol, butanol and pentanol were used as the gelation media, respectively. Discuss their infection on phase separation times, gelation rate and structure and performance of membranes;The experiments indicate that :N-methyl pyrrolidone is the best solvent for the polyamide made by ODPB-BAPP;The lower boil leads to better volatility, more phase separation times, slower gelation rate and is propitious to compact surface;The gelation rates were measured by a set of measurement system with these gelation media, and the results showed that the gelation rates for different gelation media were in the order of water > ethanol > propanol > isopropanol > butanol > pentanol. The phase sepatation times for these gelation media were measured by a phase separation kinetics measurement apparatus. is shown that finger-like membrane cross-sectional morphology results from the case of instantaneous demixing, and sponge-like membrane cross-sectional morphology results from the case of delayed demixing.The solvents with more volatility and slower gelation rate are propitious to form compactsurface
is a new technology of membrane separation for the separation of liquid mixtures,which based on the membrane’s different selectivity towards the various components in the mixture. has special advantage in the use of the separation of homogenous mixtures such as azeotropic,closing-boiling and isomeric mixtures,which are difficult or impossible to separate by conventional methods.The purpose of this work is studying pervaporation membrane used in the seperation of dilute alcohol aqueous solution . is one of the vital technologies of priducing fuel alcohol.In this paper,a plat Polydimethylsiloxane ( ) composite membrane was prepared by coating thin active layer on polyvinylidene fluoride(PVDF) which is singled out to act as supporting layer. The experiment of the separation of ethanol from dilute ethanol aqueous solution with the -PVDF composite membranes was carried out. The effect of the operating conditions temperature was studied. The PDMS-PVDF composite membranes have moderate selectivity towards ethanol,stable permeate flux and separation factor.An increase of the temperature results in an increase of the total flux and separation factor.The permeating flux conformed to Arrenhenius equation.Polydimethysiloxane (PDMS) membranes filled with ZMS-5 were prepared, the effect of the different Si/Al ratio on the separation of ethanol from dilute ethanol aqueous solution was studied The results showed that the bigger ratio of ,the better separation results was got;And the best filled content of zeolit was 30%.Also the swelling characteristics of the zeolite filled PDMS membranes dipped in ethanol-water solutions were investigated by a series of experiments. Results are demonstrated that the swelling ratio of PDMS membrane increased quickly with the change of filled content of zeolit within the same temperature and ethanol aqueous solution.And the swelling ratio of PDMS membrane increased with the ethanol concentration. Swelling selectivity factor of zeolite filled PDMS membrane decreased with the increasing temperature.The effect of the temperature and feed concentration on the swelling selectivity factors and swelling ratios were studied.
Experimental Research on Oil-Water Separation Based on Coalescence and Membrane Separation Technology
The oil/water separation technology is widely used in the modern industrial fields. At present, there are many methods applied in the oil/water separation, however, the theory and experimental study of these methods is not sufficient. This paper developed a set of test device based on the coalescence andseparation technology and attempt to study the factors that impact the effect of coalescence and separation by experiment.Appling this test device, used two kinds hydrocarbon mixed water systems, coalescence separation and membrane separation was carried out, the factors influenced the performance of coalescence separation and membrane separation such as flux, temperature, original water content etc. is studied. Finally, this paper gets the conclusion of the above parameters influenced separation effect.In addition, the paper also combines the coalescence separation and membrane separation to achieve not only efficient separate water from the # 32 of the turbine oil, but also to achieve environmental emission of the sinking water from coalescence separation. Today, the shortage of energy and water resource more and more serious, the pressure of environmental problem is increasing without interruption. This paper has significance realistic meaning.
In the powder industry classification is one of the most importantoperation, which makes the particle size suit to the demand of powder product. With the rapid development of materials science, strict requirements are proposed for the preparation of powder, such as lower limits on diameter size, narrower standard deviations on size distributions, and the like. As the third-generation dynamic air classification equipment, has high classification precision and good . has been widely utilized in different fields, such as in the materials, chemical industry, mineral processing, pharmaceuticals, foods, and so on. Flow field in the is complex and its distributions determine the particle movement trajectory. In this study, simulations and measurements were carried out to investigate the flow field characteristics in .Simulations of flow field characteristics were performed by the software of Fluent and measurements of air flow between blades of rotor cage of turbo air classifier were also carried out, the flow field simulation results match the results of measurements. The study indicates that: when the inlet velocity is settled, there is a vortex near the impeller blade when rotary speed is low and the vortex’s orientation is accordant to rotor cage, there will be a counter-rotating vortex between blades when rotary speed is too high and the vortex’s orientation is contrary with rotor cage. So when the inlet velocity settles, there must be a critical rotation speed to make the flow field between the blades stablest, the intensity of vortex is correlative to rotation speed of rotor cage and would weaken along with the rotation speed approaching the critical rotation speed.The structure improvement of rotor cage of turbo air classifier were done and the air flow between blades can be optimized by changing the setting angle and shape of blades. Compared with conventional classifier, air flow in New-structure1 is more symmetrical, the intensity of vortex is decreased especially when the rotary speed is high. The New-structure rotor cage is favorable for particle dispersion before separation and its s excelled conventional turbo air classifier.