www.pall.comCoalescersBring down costs through advancedphase separation technology
Pall Phase Separation Technologyfor Control and Protection of Your PlantContentsThree Essential PhaseSeparation Steps.3Pall Liquid/Gas Coalescers.4Comparison of Liquid/GasSeparation Equipment .6Pall Liquid/Liquid Coalescers.7Comparison of Liquid/LiquidSeparation Equipment.8Pall Coalescer Configurations.9Liquid/Gas and Liquid/LiquidApplication Tables .10-13A Powerful Resource forControl, Protection, and Teamwork .14Pall Worldwide Offices .Back Cover2www.pall.comEvery year, refineries, gas processing plants, andpetrochemical plants around the world spend millionsof dollars needlessly on their operations. Maintenancecycles are shorter than they should be; operating costsare higher than necessary; and unscheduled shutdownscausing lost production are all too common.Fortunately, solutions are readily available from onesource — Pall Corporation. Pall is a leader in filtration,separation and purification. Pall’s products are usedthroughout the world to meet the demanding needs ofits customers.Pall’s SepraSol liquid/gas coalescers, as well as itsAquaSep Plus and PhaseSep liquid/liquid coalescers,provide excellent coalescing efficiency, capacity, andcontaminant removal to improve your process.Pall Corporation is a unique resource for phaseseparations. Pall can help you achieve a higher degreeof product control and equipment protection throughour advanced technology and teamwork.
Three Essential Phase Separation Steps toReduce Operating and Maintenance CostsOur customers benefit from our experience in developing filtration and separationstechnology. This has reduced costs in hundreds of installations around the world.There are three essential steps to achieving cost reductions in your plant.1Preconditioning of the Fluid3Pall recommends a prefilter to minimize solids in thecoalescer influent that can plug the coalescer, reducingthe overall life and efficiency. The prefilter provides peakperformance of the coalescing system and a lower totalcost of ownership.2Coalescence of the Dispersed PhasePall high-efficiency coalescers merge small droplets ofliquid into larger ones as the fluid stream passesthrough several layers of filter media, each withprogressively larger pores. As droplets compete for theopen pores, they coalesce forming larger droplets.These larger droplets are easier to separate from thecontinuous phase fluid. The coalescer size and type aredetermined by numerous factors: physical properties ofthe fluid, flow rate, process conditions and chemicalcompatibility with process fluids and additives. Pall hasthe expertise and capability todetermine the correct coalescersize and type for your specificprocess parameters.Separation of the Dispersed Phase from theContinuous PhaseOnce large droplets are formed, they have to beseparated. In gas systems, Pall spaces the cartridgesto control the exit velocity of the gas so that coalesceddroplets are not entrained in this stream. In liquid/liquidsystems, depending on the liquid to be separated, Pallwill provide a separator cartridge which has “repelling”properties toward the coalesced liquids. Alternatively,the assembly can be designed to allow time for thecoalesced liquid to settle. When Pall works with you inall three phase separation steps, the result is greaterprocess efficiency and reduced operating andmaintenance costs.FiltrationFiltration: solid particles areremoved from the fluid streamby the filter medium.CoalescenceCoalescence: small dropletsare merged into larger onesas they pass through severallayers of filter media in thecoalescer.SeparationSeparation: gravitytakes effect, the largedroplets are separatedfrom the product fluidstream.www.pall.com3
Pall SepraSol Coalescers for SeparatingLiquids and Solids from GasesPall can eliminate a common problem — poor liquidseparation. It is a problem that eats away at profitmargins. Liquid aerosols, which are dispersed ingases, attack several critical areas of your process:compressors and turbo-equipment, amine-glycolcontactors, burner and combustion equipment, anddesiccant and adsorbent beds. Typical symptomsinclude: Compressor valves that need changing out morethan once every two years Turbo-equipment servicing more than once a year Plugging of reboiler heat exchangers or trays incontactor towers Frequent replacement of amines and glycols Frequent foaming incidents Loss of efficiency in burner and combustionequipment Frequent desiccant regeneration or replacementThe Efficient Way to Remove LiquidsLiquid aerosols are formed by three mechanisms:condensation, atomization, and reentrainment fromupstream separation equipment. Condensation andatomization almost always form very stable, fineaerosols usually smaller than one micron in diameter.Such aerosols cannot be removed by “knock-outdrums,” mist eliminators, vane packs, or conventionalcoalescers. If not removed, these aerosols candamage downstream equipment.The solution is Pall’s proprietary SepraSol coalescers.They are rated up to 99.99% removal efficiency for solidparticles 0.3 micron and larger, and reduce liquidcontent in gas streams down to 0.003 ppmw.A SepraSol liquid/gas coalescer protects a natural gas turbinefrom damage caused by liquid aerosols.4www.pall.com
Pall SepraSol Liquid/Gas CoalescersOutperform All OthersPall’s unique filter media and cartridge design canhandle higher liquid loads than conventional coalescers,resulting in the need for fewer cartridges. The proprietaryoleophobic/hydrophobic treatment of the media packpromotes rapid drainage of coalesced liquids. Effluentgas exit velocities are controlled to prevent liquidreentrainment. The result — higher flux in the smallestcost-effective package which ensures continuous andreliable performance.Left: Deposits form on a turbine blade.Right: A turbine blade protected by a SepraSol liquid/gascoalescer.Higher FluxPall’s oleophobic/hydrophobic treatment of the mediaallows it to handle higher gas velocity and higher liquidloads without allowing coalesced liquid droplets tobreak up and become reentrained.Better DrainageThis treatment also promotes rapid drainage ofcoalesced liquids and increases the liquid handlingcapacity of the media. Smaller assemblies are able tohandle higher liquid volumes at a lower capital cost,recover faster from liquid slugs, and operate at a lowercost due to the lower saturated pressure drop.Left: Clean desiccant.Right: Fouled desiccant. Change-out and regenerationcycles will be significantly extended using Pall’s SepraSolliquid/gas coalescers.Turbine bladeswww.pall.com5
Comparison of Liquid/Gas Separation EquipmentThe table below compares the various equipment available for removing aerosols.Pall SepraSol coalescers effectively remove aerosols smaller than one micron.Pall atorCyclonicSeparatorKnock-outDrumSmallest LiquidDroplet EfficientlyRemoved (Micron) 0.151010300Relative OperatingPressure DropMediumMediumMediumMediumLowSensitivity to IncreasedLiquid LoadingInsensitiveVery sensitiveMediumMediumMediumSensitivity to IncreasedFlow RateSome to noneVery sensitiveMediumMediumMediumSensitivity umMediumHigher Liquid CapacityNo Reentrainment of LiquidsBy handling several times more liquid volume withoutliquid reentrainment in effluent gas, Pall coalescersreduce equipment problems downstream. Fewer andsmaller cartridges mean a simpler, more compactsystem.The spacing of the cartridges enables Pall SepraSolliquid/gas coalescers to control the exit velocity of thegas, allowing the coalesced drops to drain effectivelyand not be reentrained in the effluent gas. The result isliquid-free gas.Fuel gas burners that are fouled do not maintain a steady, consistent flame.(Left) A failed combustor housing. You should not have to replace fouled burnernozzles (center) with new ones (right) more often than once a year.6www.pall.com
Pall AquaSep Plus and PhaseSepCoalescers for Separating Liquidsfrom LiquidsThrough better liquid/liquid separation, Pall can cure avariety of costly problems that may go undetected. Ifyou experience any of these symptoms in your process,chances are Pall can help you reduce your costs. Hazy product (not bright and clear) Sodium levels in gasoline above 1 ppm High solvent losses downstream of liquid/liquidextraction units High caustic carryover from gasoline, LPG orkerosene treating units Carryover of amine in LPG Oil and hydrocarbon in water and other aqueousstreamsDefining the ProblemsLiquid/liquid dispersions or emulsions are often formedby process operations such as liquid/liquid extractionand water washing. As liquid mixtures cool, the solubilitydecreases. In the case of steam stripped hydrocarbons,for example, as the temperature decreases, watercondenses to form a second distinct liquid phase,resulting in hazy product. Also, oil becomes dispersed inwater causing problems in wastewater treatment plants,steam systems, and in produced water from oil drilling.Interfacial TensionThe lower the interfacialtension, the more stablethe emulsion and themore difficult the liquidsare to separate.Frequently, the problemImpact of surfactants on coalescing.is the presence of asurfactant which lowersinterfacial tension.Conventional coalescersbegin to lose efficiencywhen the interfacialtension is below 20dyne/cm. In addition,No surfactant – coalescing is less difficult.a small amount ofsurfactant can disarm conventional coalescers,rendering them ineffective. Surfactants are everywhere— in corrosion inhibitors, organic acids, well treatingchemicals, sulfur compounds, and numerous chemicaladditives. Pall AquaSep Plus and PhaseSep coalescersseparate liquids with interfacial tensions as low as0.5 dyne/cm.Separating these liquids can be difficult, depending onthe physical properties of each. One of the mostimportant properties to address in sizing and selectingcoalescers is interfacial tension. Pall coalescers canhandle a broad range of interfacial tensions.An AquaSep Plus liquid/liquid coalescereliminates haze problems from refinery fuelslike gasoline, diesel, and jet fuels.www.pall.com7
Comparison of Liquid/Liquid Separation EquipmentPallSalt andAquaSep Plus/ oalescersMesh PackElectrostaticPrecipitatorTank SettlingVacuumDehydrationTowerLowestinterfacial tensionefficientlyseparatedAquaSepCoalescer:3 dyne/cmPhaseSepCoalescer:0.5 dyne/cm 2 dyne/cm 20 dyne/cm 20 dyne/cm 10 dyne/cm 20 dyne/cm 2 dyne/cmRelative operatingand maintenancecostsLowHighMediumLowHighLowHighEffect of additionaldispersed liquidon operating costLowHighLowLowHighLowMediumEffect of surfaceactive chemicalson cyReducesefficiencyReducesefficiencyNoneEffect of additionaldispersed liquidon ivity s AquaSep Plus and PhaseSep liquid/liquid coalescers separate water from hazy dieseland oil from wastewater, providing contaminant-free products.8www.pall.comOpen here for a complete selection guide for coalescer part numbers/ordering informationPall coalescers offer significant benefits over other separation technologies, asshown in the table below.
Two Configurations for Optimum SeparationEfficiencyOpen here for a complete selection guide for coalescer part numbers/ordering informationPall’s AquaSep Plus coalescers and PhaseSepcoalescer systems are available in horizontal andvertical configurations. Determining the correctconfiguration depends on the liquids in your process.Both configurations begin with a prefiltration stage toremove solid contaminants. This significantly extendsservice life, improves the fluid quality, and decreasesthe stability of liquid/liquid emulsions, makingcoalescing easier.In this configuration, the liquid/liquid mixture entersthe coalescing element and flows inside to out. Smallliquid contaminant droplets coalesce into largerdroplets which are separated by gravity and areremoved.Pall vertical liquid/liquidcoalescerConfiguration with prefilteron the left and AquaSepPlus/PhaseSep coalescershown far right. Water exitsbottom left, water-freeproduct exits bottom right.Pall’s Patented Vertical Coalescer/SeparatorStackThis is Pall’s most efficient technique for separatingtwo liquids when the dispersed fluid is water and theinterfacial tension is greater than 3 dyne/cm. Thecoalescer elements are stacked on top of a separatorelement to ensure uniform flow distribution from thecoalescer to the separator. The assembly is smallerand has a longer service life than conventionalcoalescers. After water droplets are coalesced inPall’s proprietary media, water-free liquid and largedroplets of water flow toward the separator. Thehydrophobic separator medium repels the aqueousphase, so only the water-free bulk fluid passesthrough the separator. The two liquids are removedby separate drain connections.Pall horizontal liquid/liquidcoalescerConfiguration with prefilterfar left and AquaSepPlus/PhaseSep coalescershown right. Contaminant-freecontinuous phase exits topright, liquid contaminant exitsbottom right.SeparatorThe Pall Horizontal CoalescerIf the dispersed liquid phase is not water, an AquaSepPlus coalescer or PhaseSep coalescer without aseparator is placed in a horizontal housing. It shouldbe used to separate oil from water, two non-aqueousliquids, or when the interfacial tension of twoliquids is less than 3 dyne/cm.CoalescerPall’s AquaSep Plus coalescer and PhaseSepcoalescer stack assemblywww.pall.com9
Fortunately, for each problem there is a solution:Pall SepraSol Liquid/Gas Coalescers10DescriptionPart NumberDimensionsSpecial cerCC3LGA7H13762 mm (30 in) length70 mm (2.75 in) diam.Polyesterdrainage layerLow pressure; low liquid loadSepraSolAmineCoalescerCC3LGB7H13762 mm (30 in) length70 mm (2.75 in) diam.Polypropylenedrainage layerRecovery of carried over amine;recovery of oil from ammonia gasSepraSolDoubleOpen-endedCoalescerCC3LG02H13762 mm (30 in) length70 mm (2.75 in) diam.Tie-rod seal;acetal endcapsPressure greater than13.8 bar (200 psi); low liquid load;greater than 5% aromatics in liquidSepraSolPlusCoalescerCS604LGH131016 mm (40 in) length153 mm (6 in) diam.High liquid packdesign;stainless steelendcapsLiquid loading over 100 ppmwwww.pall.com
Equipment service life between maintenance shutdownsand plant turnarounds is often shorter than it could be.The causes of increased maintenance and operatingcosts are not always obvious. The following tablespresent common symptoms that lead to costly problemsin various plant applications. A brief summary of Pall’sliquid/gas and liquid/liquid coalescers is offered aslong-term cost saving solutions.Inadequate liquid removal can create costly maintenanceand production problems.ApplicationSymptomProblemGas transmission compressorsRepairs needed in less than two yearsGas throughput below design; foulingand salting of compressor internalsReciprocating hydrogencompressorsRepairs needed in less than two yearsGas throughput below design; foulingand salting of compressor internalsAmine or glycol contactorsMore than two foaming incidentsa yearGas throughput lower than design;foaming in contactor, poor energyefficiency; fouling of exchanger andreboilerCondensable hydrocarbons in the inletgas lower the surface tension of theamine and initiate foaming episodesFuel gas burnersLess than one year betweenmaintenanceBurner nozzles plugged and frequentlymaintained; poor flame patternsDesiccant or adsorbent bedLess than three year change-out;regenerable adsorbent less than20 yearsFrequent regeneration problems;high pressure dropCompressor lube oil in refinery,gas and chemical plantsLube oil makeup greater than designHigh lube oil makeup; fouling ofdownstream equipment with lube oilOff-spec product (e.g. ammonia)Amine from contactorsAmine makeup at 2 lb/MMSCFgreater than designHigher than design amine losses;fouling of downstream equipmentHigh amine loss rateGas separation membranesFouling in less than three yearsPoor membrane separation efficiency;short service lifewww.pall.com11
The solution is advanced technology:Pall AquaSep Plus and PhaseSepLiquid/Liquid Coalescers12DescriptionPart NumberDimensionsSpecial FeaturesApplicationsAquaSep PlusCoalescerLCS2B1AHLCS4B1AH508 mm (20 in) length1016 mm (40 in) length95 mm (3.75 in) diam.Polymeric medium doesnot disarm in presenceof surfactants;integral prefilterSeparation of water 08 mm (20 in) length1016 mm (40 in) length95 mm (3.75 in) diam.Fluoropolymer mediumhas a wide rangeof chemical compatibilitySeparation of caustic oramine from hydrocarbon;separation of hydrogenperoxide from 8 mm (20 in) length1016 mm (40 in) length95 mm (3.75 in) diam.Broadest range ofchemical compatibilityMany acid and solventapplicationsSeparatorLSS2F2H508 mm (20 in) length95 mm (3.75 in) diam.Hydrophobicmedium does notallow water topass throughSeparation of waterfrom hydrocarbonswww.pall.com
Poor separation can damage equipment and reduce product quality.ApplicationSymptom - MeasuredInterfacial TensionProblemSeparation of water fromgasoline, jet fuel and diesel3 - 25 dyne/cmHaze problems cause off-spec product. Presenceof surfactants, either existing in the feedstock or addedto the system, reduce interfacial tension, increasingdifficulty of water removal.Separation of caustic fromgasoline, jet fuel and diesel0.5 - 13 dyne/cmPresence of sulfur compounds result in very stable,difficult to separate emulsionsSeparation of water from lighthydrocarbons (C6 and below)and petrochemicals5 - 20 dyne/cmPresence of surfactants, either existing in the feedstockor added to the system, reduces interfacial tension,increases difficulty of water removal.Separation of amine from LPGN/A - difficult toanalyzeLiquid/liquid contactor typically the largest source ofamine losses. Sulfur compounds contribute to stabilizingthe emulsion, making separation more difficult.Separation of hydrogenperoxide from working solution20 - 35 dyne/cmInefficient phase separationSeparation of acids frompetrochemicals andhydrocarbonsWide rangeCarryover of acids common in refinery and specialtychemical plants; small stable emulsions difficultto separateSeparation of oil from: waterWide rangeOil will foul steam system and increaseload to wastewater treatment plant anhydrous ammoniaOff-spec anhydrous ammoniaPall Liquid/Liquid Coalescer Selection GuideInterfacial tension between liquids is another factor in determiningthe correct product and configuration for your process.Process ConditionRecommended ProductContaminating fluid is aqueous,IFT 3 dyne/cmAquaSep Plus or PhaseSepcoalescer/separator stack (vertical housing)Contaminating fluid is aqueous,IFT 3 dyne/cmAquaSep Plus or PhaseSep coalescerwithout separator (horizontal housing)Both fluids are non-aqueousAquaSep Plus or PhaseSep coalescerwithout separator (horizontal housing)Contaminating fluid is oil,bulk fluid is waterAquaSep Plus or PhaseSep coalescerwithout separator (horizontal housing)www.pall.com13
Pall Corporation — A Powerful Resourcefor Control, Protection, and TeamworkPall Corporation is a filtration, separation and purificationleader providing solutions to meet the critical fluidmanagement needs of customers across the broadspectrum of life sciences and industry. Pall works withcustomers to advance health, safety and environmentallyresponsible technologies. The Company’s engineeredprod