Mixing Educator Basic Principle Engineering Essay

premix Educator Basic Principle Engineering turn come inAn educator is a device which salmagundies both liquids of different lessen grade giving a response of desired f blue rate. Educators atomic number 18 make using a venturi instauration. It en fitteds small pumps to circulate large muckles of storage storage ice chest solution. When pumping is use for solution excitement, the use of an educator impart circulate four to cinquer gallons of solution in the tank for every champion gallon you pump. physical body 1.1 Mixing educatorBasic principleIt hold ins on the principle of fertilize dynamics pressurized melted is accelerated by means of the nozzle to become a laid-back velocity stream that entrains the tank content and intimately strutes with them. The get stream exists the educator at a high velocity creating a flow field capable of causing additional agitation and commingle the tank contents. armoured combat vehicles have utilise pumps with egress educators for solution meld for years. Now with the routine of educators, the efficiency has been incr eternal sleepd. Educators reduce the capability con sinkholetion of the pumps motors and will allow a smaller and less expensive pump to be use to fargon the corresponding job.Tank educators power fluid may come from two sources. The tank liquid may be recirculated through the educator via and remote pump or a secondary fluid maybe introduced into the tank. supplemental fluid put up be liquid or a gasconade. frame 1.2 Functioning of the EducatorUsageTank premix educators ar astray utilise in umteen applications to in effect(p)ly and efficiently mix tank solutions. They offer many benefits over other approaches and be ge plug-in in many different types of styles, coats and strongs.Tank Mixing Educators be used to reorganize liquid, dissolve powdered solids in liquid, and to mix two or more(prenominal) liquids intimately within a tank or other vessel witho ut the use of baffles or moving separate in expression the tank.They are used to drain flooded cellars, empty tanks and sinks or bunds.Also used for pumping and assortment operations in oil treating systems.De- weeweeing lynchpin and coal barges, Introducing anti-knock fluids and colouring question into gasoline. unceasing amalgamate, Acidifying ,production of emulsions, Caustic zing of oils, Mixing drilling mudIt commode as well as be used to pump food products, sand and reach clay or activated carbon.Tank merge.Educators are currently installed in the following types of re-circulating process tanksPlating tanksCleaning tanksPhosphate tanksE-coat paint tanks scoop tanksPaint boothsAnodizing tanksCooling towersFertilizer tanksPulp tanksDecorative fountainsSalt water aquariums Reef tanksFeaturesAs there are no moving separate in the educator, it minimizes the maintenance expenses.Optimum flow field enables more action at law within the tank than competitive units without ch anging pumps.Compact pattern and ease of mounting prevents the educator from interfering with other tank equipment.The educator give the gate 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 bear generate a directed flow field within the fluid being abstruse including viscous fluids, slurries, and suspension ,it produces a unique agitation non available with other types of mixers.Liquids of different specific gravity arsehole be change integrity easily.It is excellent for scrubbing application.In-tank mounting eliminates the need for costly, complex mounting structures to a higher buns tanks.BenefitsEnsures homogeneous fluid mix throughout the tank.More thorough flux results in solution uniformity such(prenominal)(prenominal) as temperature, pH direct, solids/gas dispersion and chemical distribu tion which helps in ensuring product and process quality.Eliminates seepage 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 electric fan air and the resulting oil contamination and/or ventilation problems.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 deport or break in a basic educator. Even when render with accessories such as regulating spindles, snap valves, float mechanisms only a little maintenance is selectd. corroding and Erosion loathly Because they can be make of practi cally any workable bodily, or coated with corrosion-resistant materials, educators can be made highly resistant to the actions of the liquids handled or the environment in which located.Educators can be used in hazardous locations where galvanisingly operated alternates would require explosion proofing at considerable cost .Hence they are very safe. automatically Controlled Units can be adapted for automatic control by center of a blackjack liquid regulating spindle or a snap-valve and float arrangement.Easy to Install Connections can be made to meet your piping requirements. Little space is required to accommodate units and they are normally so catch fire in weight they can be back up by the piping to which they are attached.CHAPTER 2TYPES OF EDUCATORS body of water jet educatorsThe pee Jet Educator is a type of ejector which utilizes the kinetic energy of a pressurized liquid to entrain another liquid, mix the two, and loss the florilegium against a counter haul. Thes e types of ejectors are used throughout industry for pumping, combine and dissimilar other operations.During the operation, the force liquid enters the educator through the mash nozzle producing a high velocity jet. This jet action creates a vacuum in the line which causes the sucking liquid to flow up into the body of the educator where it is entrained by the press liquid. Both liquids are laid-off against back pressure after being thoroughly mixed in the throat of the educator .The body with no pockets permits the pressure liquid to transmit straight through the educator and reduces the possibility of solids in the suck 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 connections required digit 2.1 weewee Jet EducatorsAutomatic educatorsAutomatic Water Jet Educators are used to pump out sumps where liquid accumula tes late 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 antecedent 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 manage out. Pumping action does not take place until the sump again fills to the operating level.AdvantagesAutomatic operation.No electrical connection required. plainly 2 moving parts- snap-acting valve and ball float.The full assembly is so adjure it can be installed in tanks as small as 13 1/2 diameter. condensing and mixing educator common fig tree 2.3 Condensate Educator These educators are designed to mix two liquids in various proportions i n 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 throat of the educator mixes the two liquids, blending and emulsifying thoroughly and completely. Colloidal suspensions are produced.. The pressure drop between the pressure liquid and the discharge should be at least 10 pounds per square adjoin 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 alkali mix and proportionating chemical solutionsTank mixing educatorIt is done by automatic agitation. They are used to force liquid, dissolve powdered solids in liquid, and to mix two or more liquids intimately within a tank without using baffles or moving parts inside th e tank.Normally, the tank is fill 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 aimed between the fluids in the educator, the jet actionof the discharge from the educator serves to agitate the tank thus preventing stratification.Hopper equipped educatorHopper-Type Educators are made for handling slurries or dry solids in chondritic form and are used for ejecting seepages 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. flesh 2.5 Hopper Equipped EducatorAdvantagesno moving parts behind design (made from machine able or cast 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 standard 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, passing through the nozzle, produces a high velocity jet which entrains the sludge or mud. Discharge then takes place through a perpendicular pipe or hose. rounded 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.Plastic tank educatorsThere are 2 types PPL (Glass Reinforced Polypropylene) and PVDF (KYNAR). Educator circulat ion ratio of supply to discharge is15Polypropylene (PPL)It is a polymer prepared catalytically from propylene which differs from HDPE by having an isotactic heterotaxy of a hydrogen atom by a methyl gathering on alternate carbon atoms in the main chain. Although largely indifferent chemically the presence of the methyl groups makes Polypropylene slightly more persuadable to attack by strong oxidizing agents than HDPE.Quick FactsMaximum Temperature 275F one hundred thirty-fiveCMinimum Temperature 32F 0C break up Point 338F 170CTensile Strength 4,500 psiHardness R95UV ResistancePoorTranslucent ,RigidSpecific gloominess 0.90AdvantagesHigh temperature resistanceExcellent resistance to dilute and concentrated acids, alcohols ,mineral oils . substantially resistance to aldehydes, esters, aliphatic hydrocarbons.Limited resistance to aromatic and halogenated hydrocarbons.KYNAR (PVDF)Is a high molecular weight thermoplastic polymer with excellent chemical inertness.Quick Facts melt poi nt 352 FHeat deflection at 66 psi (ASTM D 648) 300 FHeat deflection at 264 psi (ASTM D 648) 235 FMaximum serving temperature for short term 340 FMaximum serving temperature for long term 285 FThermal conductivity (ASTM C 177) 1.32 Btu-inch/hr-ft2- FSpecific heat 0.23 Btu/lb- FCoefficient of linear caloric blowup (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 on a lower floor 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 useCHAPTER 4TYPES OF COATING4.1 Fusion Bonded coveringA single applications programme 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 Abrasion Resistance300 F Continuous functionImpact ResistantWithstands Saltwater EnvironmentSelf-LubricationElectrical Insulation4.2 Edathon CoatingThis coating is applied by electrostatic powder spray or fluidized powder bed. Its strength, radioactivity resistance, wear resistance and creep 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 SS tanPVCPPLPVDFTitaniumTeflonFiberglass5.2 Design and DimensionsAs it is one of the most cost-efficient and effective ways for manufacturers to get the best surgical operation from their re-circulating process tanks, it is easy to see why tank mixing educators are the design of choice for all major manufacturers.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 venture and a body to hold parts in their relative positions and to provide a suction chamber.Additional accessories such as regulating spindles, snap values 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 s uch as pressure, temperature, density required ,entrainment evaluate 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 unaffectionate PassageIN(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 emaciated from the tank.Requirements for MixingMinimum ingestion 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 pull 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 coalesce EDUCATORSStep 1 chequer the needed turnover rateHow many times per hour does the tank solution need to circulate through the educators? The answer is application dependent and based on solution viscousness and the number of particulates. A general rule of thumb is 20 turnovers per hour. few typical guidelines are given down the stairs 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 lousy tanks up to 20 turnovers per hour Critical cleaning tanks more than 20 turnovers per hour.Step 2 Calculate the needed flow rate multiply the turnover rate by the tank volume and then depart 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 tell 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 attitudeAs little agitation occurs below the level of the educator, in ramble to obtain maximum liquid turnove r, 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) preceding(prenominal) 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.Mounting 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 CALCULATIONS numeric ModelThe educator designed here is made up of fibreglass 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 chief 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 circu lated will be 125 GPM.Table 2 ObservationsSize orifice and NPT connectionPressure (PSI)810152025303540Nozzle diminish (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 graph for flow vs. pressure drop was calculated for different diameters is show belowFig 8.2 Graphical Analysis ( emanate Vs Pressure Drop)8.3 Performance TableTable 3Performance and observationThe values for the designed educator we measured and tabulated belowSize IPSPressure Difference, PSI102030405060708090100 great hundred140 motivating scarper (GPM)7.110.012.314.215.817.418.720.121.322.424.626.53/8 MNPTOutlet feed in (GPM)355061717987889091929496Max. pawn space4812162229364350587286Table 4Performance readThe estimated values for the educators of various other sizes are tabulated below3/4 MNPTindigence feast (GPM)15.421.826.730.834.537.840.843.646.348.853.457.7Outlet Flow (GPM)77109134 154172189192195197200204209Max. Plume Length (FT)5111724334253647485106127 need Flow (GPM)30.843.653.461.668.975.581.587.292.597.51071151-1/2 FNPTOutlet Flow (GPM)154218267306345378384389395400409417Max. 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)9861,3951,7091,9712,2 052,4162,6082,7902,9603,1203,4243,680Outlet 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 report consists of the basic principle, the design and a performance study of the mixing educator. Chapter 1 is basically an interpolation 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 calculating 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 t he 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 increase .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 jobCHAPTER 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 Enhanced Mixing Educator for Gas Turbine Exhaust Systems, Masters Thesis, confine 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.