Mixing Educator Basic Principle Engineering Essay

Mixing Educator staple fibre Principle Engineering EssayAn pedagog is a device which mixes dickens mobiles of different fly the coop crops liberal a solution of desired flow rate. Educators are made using a venturi design. It enables small pumps to circulate large lots of store solution. When pumping is employd for solution zymosis, the use of an educator will circulate four to tailfin gallons of solution in the armored combat vehicle for every one gallon you pump. material body 1.1 Mixing educatorBasic principleIt operates on the principle of flow dynamics pressurized fluid is accelerated through the nozzle to become a high velocity stream that entrains the ice chest content and intimately mixes with them. The combined stream exists the educator at a high velocity creating a flow field capable of causing supernumerary agitation and salmagundi the store limit. stores have used pumps without educators for solution mixing for years. Now with the usage of educators, th e skill has been increased. Educators reduce the energy consumption of the pumps motors and will surrender a smaller and less pricey pump to be used to perform the equal job. tankful educators motive fluid may come from two sources. The tank liquid may be recirculated through the educator via and external pump or a secondary fluid maybe introduced into the tank. Secondary fluid tolerate be liquid or a accelerator.Fig 1.2 Functioning of the EducatorUsageTank mixing educators are widely used in legion(predicate) applications to effectively and efficiently mix tank solutions. They offer many benefits over other approaches and are available in many different fictional characters of styles, sizes and materials.Tank Mixing Educators are used to agitate liquid, dissolve fine-grained solids in liquid, and to mix two or more liquids intimately at heart a tank or other vessel without the use of baffles or moving parts inside the tank.They are used to drain flooded cellars, empty ta nks and sumps or bunds. overly used for pumping and mixing operations in oil treating systems.De- water supplying backbone and coal barges, Introducing anti-knock fluids and colouring matter into gasoline.Continuous blending, Acidifying ,production of emulsions, Caustic zing of oils, Mixing drilling bog downIt rouse also be used to pump food products, sand and filter clay or activated carbon.Tank mixing.Educators are currently installed in the following lineaments of re-circulating process tanksPlating tanksCleaning tanksPhosphate tanksE-coat paint tanksSludge tanksPaint boothsAnodizing tanksCooling towersFertilizer tanksPulp tanksDecorative fountainsSalt water aquariums lower tanksFeaturesAs there are no moving parts in the educator, it minimizes the maintenance expenses.Optimum flow field enables more activity within the tank than competitive units without changing pumps.Compact design and ease of raise prevents the educator from interfering with other tank equipment.The ed ucator advise be installed in a wide variety of open vessels or closed tanks.It eliminates stratification and promotes a homogenous tank with relation to pH, temperature, solids or gas dispersion, and distribution of chemicals.As the educator preempt generate a directed flow field within the fluid being mixed including viscous fluids, slurries, and suspension ,it produces a unique agitation not available with other types of mixers.Liquids of different specific gravity can be mixed easily.It is excellent for scrubbing application.In-tank mounting eliminates the need for costly, complex mounting structures above tanks.BenefitsEnsures homogeneous fluid mix end-to-end the tank.More thorough mixing results in solution uniformity such as temperature, pH level, solids/gas dispersion and chemical distribution which helps in ensuring product and process quality.Eliminates sludge build-up and reduces the tank cleaning time.Enables the usage of small pumps to circulate large volumes of tank solution. smaller pumps are less costly to purchase- Units are small in relation to the work they do and cost is correspondingly low.Smaller pumps are less expensive to operate.Simplifies operation and maintenance as there are no moving parts it eliminates the need for compressed or blower air and the resulting oil befoulment and/or ventilation hassles.Self-Priming Educators are self-priming. They operate equally well in continuous or intermittent service.No Moving Parts Educators have a very simple design and are reliable. There are no moving parts to wear or break in a base educator. Even when equipped with accessories such as regulating spindles, snap valves, float mechanisms only a little maintenance is required.Corrosion and Erosion Resistant Because they can be made of practically any workable material, or coated with corrosion-resistant materials, educators can be made highly resistant to the transactivenesss of the liquids handled or the environment in which located .Educators can be used in hazardous locations where electrically operated alternates would require explosion proofing at considerable cost .Hence they are very safe.Automatically Controlled Units can be adapted for automatic control by means of a pressure liquid regulating spindle or a snap-valve and float arrangement. idle to Install Connections can be made to suit your piping requirements. Little space is required to accommodate units and they are normally so light in weight they can be supported by the piping to which they are attached.CHAPTER 2TYPES OF EDUCATORS weewee jet educatorsThe Water Jet Educator is a type of ejector which utilizes the kinetic energy of a pressurized liquid to entrain another liquid, mix the two, and freeing the mixture against a counter pressure. These types of ejectors are used throughout industry for pumping, mixing and confused other operations.During the operation, the pressure liquid enters the educator through the pressure nozzle producing a h igh velocity jet. This jet action creates a vacuum in the line which causes the suction liquid to flow up into the body of the educator where it is entrained by the pressure liquid. Both liquids are discharged against back pressure after being thoroughly mixed in the throat of the educator .The body with no pockets permits the pressure liquid to move straightaway through the educator and reduces the possibility of solids in the suction material collecting and clogging. In the suction chamber the pressure drop held to a minimum.AdvantagesLow initial cost.Self-primingEasy to installLittle or no maintenance requiredNo moving partsNo electrical familiaritys requiredFig 2.1 Water Jet EducatorsAutomatic educatorsAutomatic Water Jet Educators are used to pump out sumps where liquid accumulates slowly but must be evacuated when it has reached a predetermined level.As the liquid in the sump (basin, tank, cellar, bilge, etc.) is accumulated, it raises the ball float until the upward action of the float opens the snap-acting valve, admitting motive fluid into the pressure connection of the educator.The jet action of the motive fluid creates a vacuum in the educator and entrains the suction fluid, discharging both the fluids then. The sump level drops to a point where the snap acting valve shuts off ,as the suction fluid is pumped out. Pumping action does not take place until the sump again fills to the operating level.AdvantagesAutomatic operation.No electrical connection required. only if 2 moving parts- snap-acting valve and ball float.The full assembly is so compact it can be installed in tanks as small as 13 1/2 diameter.Condensate and mixing educatorFig 2.3 Condensate Educator These educators are designed to mix two liquids in various proportions in operations where the pressure liquid is the greater proportion of the mixture.In operation, the pressure liquid issues from the nozzle at high velocity and entrains the suction liquid. The high turbulence in the throa t of the educator mixes the two liquids, blending and emulsifying thoroughly and completely. Colloidal suspensions are produced.. The pressure drop amidst the pressure liquid and the discharge should be at least 10 psi for adequate mixing, and the difference between the discharge pressure and the suction pressure should not exceed 75% of the difference between the operating pressure and the suction pressure.ApplicationsRemoval of condensateMixing gasolineDiluting acids and alkaliBlending and proportionating chemical solutionsTank mixing educatorIt is done by mechanical agitation. They are used to agitate liquid, dissolve powdered solids in liquid, and to mix two or more liquids intimately within a tank without using baffles or moving parts inside the tank.Normally, the tank is filled by means of the educators. Mixing occurs as soon asthe level of liquid in the tank covers the suction of the educator. In addition to themixing obtained between the fluids in the educator, the jet acti onof the discharge from the educator serves to agitate the tank then preventing stratification.Hopper equipped educatorHopper-Type Educators are made for handling slurries or dry solids in granular form and are used for ejecting sludges from tank bottoms, for pumping sand from filter beds and for washing and conveying granular materials.Typical materials handled include borax, charcoal, diatomaceous earth, lime, mash, fly ash, rosin, rock and granulated salt, sand, dry sawdust, light soda ash, dry sodium nitrate, powdered sulphur, wheat and many others.Fig 2.5 Hopper Equipped EducatorAdvantagesno moving partseasy design (made from machine able or take in able materials)no maintenance requiredWater jet sand educatorWater Jet Sand and Mud Educators are used in pumping out wells, pits, tanks, or sumps where there is an accumulation of sand, mud, or other material not easily handled by the mensuration educator. Heavy sludge residue can be handled easily from refining operations. They have an open suction and are designed to be submerged in the material being handled. The pressure liquid, release through the nozzle, produces a high velocity jet which entrains the sludge or mud. Discharge then takes place through a vertical pipe or hose.Annular Multi-Nozzle Water Jet EducatorAnnular Multi-Nozzle Water Jet Educators are designed to handle solids and semi-solids. Water is introduced though the nozzles on the periphery. The pressure water creates a vacuum which draws in and entrains the material being handled.Fig 2.7 Multi -nozzle Water Jet Educator.AdvantagesHighest efficiencyLow dischargeHigh air handling capacities. flexible tank educatorsThere are 2 types PPL (Glass Reinforced Poly propylene) and PVDF (KYNAR). Educator circulation ratio of supply to discharge is15Polypropylene (PPL)It is a polymer prepared catalytically from propylene which differs from HDPE by having an isotactic replacement of a hydrogen atom by a methyl group on alternate carbon atoms in the main chain. Although for the nigh part unreactive chemically the presence of the methyl groups makes Polypropylene slightly more susceptible to attack by strong oxidizing agents than HDPE.Quick FactsMaximum Temperature 275F cxxxvCMinimum Temperature 32F 0CMelting Point 338F 170CTensile Strength 4,500 psi inclementness R95UV ResistancePoorTranslucent ,RigidSpecific Gravity 0.90AdvantagesHigh temperature resistanceExcellent resistance to dilute and concentrated acids, alcohols ,mineral oils .Good resistance to aldehydes, esters, acyclic hydrocarbons.Limited resistance to aromatic and halogenated hydrocarbons.KYNAR (PVDF)Is a high molecular weight thermoplastic polymer with excellent chemical inertness.Quick FactsMelting point 352 F wake up deflection at 66 psi (ASTM D 648) 300 FHeat deflection at 264 psi (ASTM D 648) 235 FMaximum lot temperature for short term 340 FMaximum serving temperature for long term 285 FThermal conductivity (ASTM C 177) 1.32 Btu-inch/hr-ft2- FSpeci fic heat 0.23 Btu/lb- FCoefficient of linear thermal expansion (ASTM D 696) 7.1105Applicable temperature range for thermal expansion 50-300 FAdvantagesHighly resistant to oxidizing agents and halogens.Completely resistant to aliphatic aromatics, alcohols, acids and chlorinated solvents.Resistant to most acids and bases.Mechanically strongThermally stableResistant to low temperaturesSelf-extinguishingNon-toxicHigh dielectric strengthStable to ultraviolet and extreme conditions.CHAPTER 3CUSTOM TANK EDUCATOR MANIFOLD DESIGNManifold designs can be customized for various applications. Shown below is a type of design used by various industries for a number of applications. The main advantage of such a design is that it is highly efficient.Fig 31 Manifold DesignCHAPTER 4TYPES OF cover4.1 Fusion Bonded CoatingA single coating offers excellent abrasion resistance that it can withstand the punishment of sand blasting.5-3 mils thick coating can be applied.Fig 4.1Machine ableExcellent Abra sion Resistance300 F Continuous ServiceImpact ResistantWithstands Saltwater purlieuSelf-LubricationElectrical Insulation4.2 Edathon CoatingThis coating is applied by electrostatic powder spray or fluidized powder bed. Its strength, radiation resistance, wear resistance and spectre resistance are greater than those of other fluoropolymers such as PTFF,FEP or PEA.Excellent Corrosion ResistanceExcellent Abrasion Resistance300 F Continuous ServiceGood Non-Stick CharacteristicsExcellent Dielectric InsulationResistance to radiationHigh chemical and temperature resistantFig 4.2 Edathon CoatingEdathon Coated Tank NozzleCHAPTER 5DESIGHNING OF AN EDUCATOR5.1 Materials of ConstructionCarbon steel316 SSBronzePVCPPLPVDFTitaniumTeflonFiberglass5.2 Design and DimensionsAs it is one of the most cost-efficient and effective ways for manufacturers to get the best performance from their re-circulating process tanks, it is easy to see why tank mixing educators are the design of weft for all major ma nufacturers.To obtain optimal mixing performance, it is important to understand these product differences and how to specify and install educators.Liquid mixing educators consists of a nozzle, a imperil and a body to hold parts in their relative positions and to provide a suction chamber.Additional accessories such as regulating spindles, snap set and floats for controlled agitation can also be added to the design.Liquid jet educators are manufactured in a variety of types and sizes as well as materials .The standard type are264 type-0.5 inch to 6 inch266 type-0.5 inch to 6 inch242 type-0.5 inch to 24 inchBefore determining the correct type and size of the educator certain variables such as pressure, temperature, density required ,entrainment rates and operating conditions must all be considered.Fig 5.2 DesignFig 5.3 Dimensions of an EducatorTable 1 Types of educatorsDimension ADimension BDimension CDimension DSizeMax Free passing playIN(mm)IN(mm)IPS(mm)IN(mm)3/80.26565.00(127)2. 50(64)3/8 MNPT(10).50(12)3/40.40627.25(184)3.69(94)3/4 MNPT(20).81(20)1-1/20.562510.88(276)5.50(140)1-1/2 FNPT(40)1.12(28)20.812514.50(368)7.69(195)2 FNPT(50)1.62(41)31.187522.00(559)11.75(298)3 FNPT(80)2.50(63)4consult25.00(635)12.00(305)4 FNPT(100)3.00(76)6consult35.00(889)25.00(635)6 FNPT(150)4.50(114)CHAPTER 6WORKINGAs the motive liquid enters the tank contents into the suction openings ,a thorough mixing takes place within the unit before being discharged. Further mixing and agitation is provided by the discharge flow within the tank. The motive fluid is drawn from the tank.Requirements for MixingMinimum admission pressure 10 PSIGMaximum inlet pressure 100 PSIGFor efficient operation the inlet pressure should be within the range of 20 to 70 PSIG.As the solution is pumped through an educators orifice, a low pressure area is created that acts to aspirate solution from behind the bell shape of the educator and direct the solution out of the bell end.For each gallon of solution that is pumped through the educator, five gallons of additional solution is circulated within the tank.Fig 6.1 WorkingCHAPTER 7GUIDELINES FOR SPECIFYING MIXING EDUCATORS measuring 1 Determine the needed turnover rateHow many multiplication per hour does the tank solution need to circulate through the educators? The answer is application dependent and based on solution viscosity and the number of particulates. A general rule of thumb is 20 turnovers per hour.Some typical guidelines are given below Plating and rinsing tanks 10 to 20 turnovers per hour although (some plating tanks may require more than 30 turnovers per hour). Cleaning tanks at least 10 turnovers per hour Heavily soiled tanks up to 20 turnovers per hour captious cleaning tanks more than 20 turnovers per hour.Step 2 Calculate the needed flow rateMultiply the turnover rate by the tank volume and then split up by 60.ExampleLet, turnover rate/hr. =10Tank volume=800 gallonsThen 10 x 800=800 gphNow 8000 60 =133.3 gpmStep 3 Determine the needed inlet flow rateAs educators mix at a 51 ratio, take the gallons (litters) per minute and divide by 5.Example133.3 5 = 26.7 gpmStep 4 Determine the educator size required with the help of the performance table.Step 5 Determine how many educators you needMultiple educators may be used to obtain the needed flow rate or to prevent stagnation which is a common problem in square and rectangular tanks. In general, using multiple educators in larger tanks will provide more effective mixing than one centrally located educator.Step6 Determine the educator placementAs little agitation occurs below the level of the educator, in order to obtain maximum liquid turnover, the educators should be positioned as close as possible to the bottom of the tank.If settling cannot be tolerated, install the educators 1 (.3 m) above the bottom of the tank.Educators should be placed so the flow field will reach the farthest and highest liquid level at the opposite side of the tank.Mount ing adapters are available to direct flow as needed.The educators should be placed 12 (.3 m) apart for uniform and even agitation.CHAPTER 8OBSERVATIONS AND CALCULATIONSMathematical ModelThe educator designed here is made up of fiberglass and is based on the operating data for type 264. For the test the eductant used is water and the suction fluid used is blue ink. Eductant pressure, suction head and discharge pressure were varied and the eductant and suction flows were measured. For example The following table shows the values calculate when using a .48 educator, with 15 PSI pressure available. The flow rate through the nozzle will be 25 GPM-The total amount circulated will be 125 GPM.Table 2 ObservationsSize orifice and NPT connectionPressure (PSI)810152025303540Nozzle turn tail (USGPM).201/4 NPT3.23.54.35.05.56.16.67.0.30 3/86.27.59.210.711.913.114.115.373/411.813.5171921232527.48118.721252933363942.621 1/2334147535863678.2 Graphical AnalysisThe graphical record for flow vs. pr essure drop was calculated for different diameters is show belowFig 8.2 Graphical Analysis ( diminish Vs Pressure Drop)8.3 Performance TableTable 3Performance and observationThe values for the designed educator we measured and tabulated belowSize IPSPressure Difference, PSI102030405060708090100120140 need Flow (GPM)7.110.012.314.215.817.418.720.121.322.424.626.53/8 MNPT spillage Flow (GPM)355061717987889091929496Max. Plume Length4812162229364350587286Table 4Performance StudyThe estimated values for the educators of various other sizes are tabulated below3/4 MNPTMotive Flow (GPM)15.421.826.730.834.537.840.843.646.348.853.457.7Outlet Flow (GPM)77109134154172189192195197200204209Max. Plume Length (FT)5111724334253647485106127Motive Flow (GPM)30.843.653.461.668.975.581.587.292.597.51071151-1/2 FNPTOutlet Flow (GPM)154218267306345378384389395four hundred409417Max. Plume Length (FT)7.5162434466075901051201501802 FNPTMotive Flow (GPM)61.687.2107123138151163174185195214231Outlet Flow (GPM) 308436534616689755767778789799818835Max. Plume Length (FT)11233448658510612148170212255Motive Flow (GPM)1422012462833173473754014264494915313 FNPTOutlet Flow (GPM)7081,0031,2281,4171,5851,7371,7641,7901,8151,8361,8801,920Max. Plume Length (FT)16345173991291611932252573223864 FlangedMotive Flow (GPM)246349427493551604652698740780856920Outlet Flow (GPM)1,2321,7442,1362,4482,7603,0243,0723,1123,1603,2003,2723,336Max. Plume Length (FT)224160951321641962282602953604246 FlangedMotive Flow (GPM)4936988549861,1021,2081,3041,3951,4801,5601,7121,840Outlet Flow (GPM)2,4643,4884,2724,8965,5206,0486,1446,2246,3206,4006,5446,6728 FlangedMotive Flow (GPM)9861,3951,7091,9712,2052,4162,6082,7902,9603,1203,4243,680Outlet Flow (GPM) (FT)4,9286,9768,5449,79211,04012,09612,38412,44812,64012,80013,08813,34410 FlangedMotive Flow (GPM)1,9712,7903,4183,9424,4104,8325,2165,5815,9206,2406,8487,360Outlet Flow (GPM)9,85613,95217,08819,58422,08024,19224,57624,89625,34425,60026,17626,688CHAPTER 9CONCLUSIONThis re port consists of the basic principle, the design and a performance study of the mixing educator. Chapter 1 is basically an introduction to the topic and summarizes the principle, applications, features and advantages of the educator. Chapter 2 summarizes the different types of educators used in the industries today. Chapter 3 shows the different custom made designs. Chapter 4 shows the types of coatings used on the educators and its advantages. Chapter 5 summarizes the designing of the educator. Its consists of the educators of different dimensions and their construction. Chapter 7 summarizes the guidelines for specifying the educator. Chapter 8 consists the mathematical model and the performance study.Tanks have used pumps without educators for solution mixing for years .Now with the usage of educators ,the efficiency has been increased .Educators reduce the energy consumption of the pumps motors and will allow a smaller and less expensive pump to be used to perform the same jobCHA PTER 10REFRENCESRobert D. Blevins, Applied Fluid Dynamics Handbook, 1984.Crane Co., Flow of Fluids Through Valves, Fittings and Pipe, 1988J. R. Lawson, Educator Testing for Waste Dilution, Dec. 28, 1981.Otis, R. H., Preliminary Design Study for an deepen Mixing Educator for Gas Turbine Exhaust organizations, Masters Thesis, Restricted Distribution, Naval Postgraduate School, March 1998.Stephen W. Dudar,Preliminary Design Study of an Enhanced Mixing Educator System for the LHA (R) Gas Turbine ExhaustChapter 5.Robert H. Perry, Cecil H. Chilton, Sidney D. Kirkpatrick, Chemical EngineersHandbook, Fourth Ehtion, 1963.