DS-ME-01 Rev 3 - hatltd.com

1 DESIGN SHEETOVERVIEWE ffective separation of vapour and liquid is a primary requirement for efficientindustrial processing. W ith a vast range of fluids, physical properties, pressures,temperature and flow-rates to cover, HAT sAlphaMIST mist eliminators offereff ective separation across the :HE/GP/DS Mesh DemistersAvailable in a range of metal alloysHE/GP/DS Mesh DemistersAlso available in plastics, glass wooland dual media constructionMomentumTypes:VV Vane MistEliminatorsPlain style for vertical gas flow orfouling applicationsVH1/VH2 Vane Mist EliminatorsHookedand pocketeddesigns forimproved efficiency & performanceCycloneTypes.

2 SME Swirl Mist EliminatorAn axial flow, swirl cyclone with veryhigh capacitySME Mist Eliminator in GRPA unique, low cost alternative suitsmany applicationsMCE Multi Cyclone BundleAn effective device for theseparation of high levels of liquidsand solids in a single DESIGN SHEETA pplicationHAT sAlphaMISTm eshpad typemisteliminators remove droplets by impingementon the wire surface. The liquid collected on the filaments is then able to drain fromthe pad under gravity. They have a limited range of useful operation in which theyprovide almost complete removal of droplets down to about 3-5 microns.

3 Turndownrange of vapour rate is around 3:1. Atexcessivelyhigh vapour velocities, the liquiddroplets that impinge on the wire surface are sheared off by the vapour and re-entrained before they are ableto drain. Atverylow vapour velocities, all but thelarger droplets are able to follow the vapour path through the mesh and thus avoidimpingement; however the inherent design of the separator vessel means that inmost applications an effective turndownperformance of 10:1 can be irem eshm isteliminators are well suited to remove mechanically formedentrainmentfrom packed and trayedprocesstowers,spraycolumns,venturi scrubbers and other gas scrubbing devices.

4 The are also a widely used de-entrainment device in knock out drums and ConfigurationAlphaMIST mesh demisters consist of a pad of knitted metal or plastic wire meshusuallysandwiched between gridsfor mechanical for units lessthan about 600mmdiameter, they are normally split intosections of between 300 to400mmwide to facilitate installation through a normal vessel padsare cut slightly oversize to ensure a snug fit and thus eliminate any possible vapourby -pass either between sections or between pad and vessel wall (or shroud).Eachmesh pad is formed from crimped layers of fabric knitted from monofilament withthe direction of the crimp rotated 90 degrees in each adjacent layer to provide auniform voidage together with a highratio of filament surface per unit volume of support grids consist of a framework of 25mm x 3mm thick flat bar fixed toa grid consisting of 6mm rods usually spaced on 150mm centres to retain the meshwith minimum obstruction of the face ofthe pad.

5 The top and bottom grids areconnected by spacer rods passing through the mesh that are welded to each grid toensure the dimensional stability of the pad. Mesh pads can also be furnished withspecial heavy duty support grids where these are required to provide a workingplatform inside the can be installed either horizontally for vertical vapour flow orvertically for horizontal vapour vertical vapour flow, mesh pads arenormally either 100mm or 150mm thick and for horizontal flow are normally greaterat150 to200mm+ here mesh pad thickness exceeds 300mm, the unit isusually divided into 2 separate layers so that the sections will pass through normalvessel manways and in such cases wire screensare fitted between layers tomaintain pad integrity during DESIGN SHEETS pecificationAlphaMIST meshm isteliminators are manufactured in a wide variety of metals andsynthetics of which the following are supplied as standard.

6 -Stainless steels(types 304, 304L, 316, 316L, 321, 430)MonelNickel& nickelalloysCopper & copper alloysGlass wool or fibrePolypropyleneHalar/ PTFEThe wire mesh may be knitted and formed to provide a wide range of specificproperties to suit various applications. The following is a list of standard mesh stylesthat we supply:-STYLEAPPLICATIONSHEH ighefficiencyremoval offinemistsGPGeneralpurpose (maximumefficiency withlowpressureloss)DSDirtyservicewhere fouling is an issueMist Eliminator DesignMesh pads should be sized so that the face area provides a vapour rateofapproximately80% of them aximum purposes,suitable design velocities occurat aK-factor m/s forvertical flow,or for horizontal gas flow(due to better drainage)where:-vs=K.

7 {( L- V)/ V} (m/s) V=Vapourdensity (kg/m3) L=Liquiddensity (kg/m3)Operating pressure loss across the pad within the above design range is normallyless than kPa depending upon mesh density, pad thickness, liquid loading andvapour approximate pressure drop can be estimated from the formula:W et P (kPa) = C. ( L V) . K2. tW here C = for a typical GP style mesh demister, and t is the pad thickness inmetres. Note that the dry pressure drop is about half of the wet DESIGN SHEETFor optimum designs the K-factorshouldbe modified to take into account theoperating pressure, liquidviscosity, surface tension, liquid entrainment, etc.

8 Soplease confirm sizingagainstHAT s proprietary design ArrangementPadDepthTyp 100-250mmGrid DepthTyp 25mmGridDiameterTypVesselID 50mmPadDiameterTypVesselID+20mmSection WidthTyp 350mmGrid ClearanceTyp 25mmMesh 3 AlphaMIST DESIGN SHEETA lphaMIST MESH SPECIFICATION CHARTS tyleMaterialsApplicationWireDiametermmMe shDensitykg/m3 SurfaceAream2/m3 Voidage%NominalMicronRating*HE-1 MMetalsVery high efficiency in clean HE-2 MMetalsFine droplet removal inclean HE-3 MMetalsGeneral purpose, clean GP-1 MMetalsOptimum efficiency & GP-2 MMetalsGeneral purpose, not totally GP-3 MMetalsHeavy duty & gas DS-1 MMetalsLight DS-2 MMetalsModerate DS-3 MMetalsHeavy fouling HE-1 GGlass WoolVery fine HE-2 GGlass WoolFine HE-1 PPolypropyleneAcid HE-1 XMetal/PP MixMist removal of polar and non-polar GP-1 PPolypropyleneChemical scrubber GP-1 TTeflonVery corrosive DS-1 PPolypropyleneLow pressure drop air * 99% Removal at optimum velocitythrough a 150mm padVane Mist 3 AlphaMIST DESIGN SHEETV anemist eliminatorsconsist of aseries of plates or vanes spaced toprovide passage for vapour flow

9 Andprofiledwithanglestoprovidesufficient change of direction for liquiddroplets to impact, coalesce and drainfrom the surfaces of the plates. HATdesign and manufacture a range ofAlphaMIST vanestyleswhichprovidethefollowing benefits: High vapour capacity Resistance to fouling Low pressure loss Effective removal of high liquidloadsThe "VV" Rangeis a plain, non-pocketed styledesigned forlargerdroplet removal from vapourin normal,lightfouling applicationswith eithervertical or horizontal gas V-V Droplet SeparatorThe "VH" Rangeisdesigned fordroplet removal from vapour flowinghorizontally.

10 In this configuration, thevanes are fitted withhooks (V H11) orpockets (VH-2)to trap and drain thecollected liquid. They are generallyeffective at higher vapour velocities atwhich smaller droplet size removalcan VH-1 Droplet SeparatorBoth of the above styles can besupplied in sections for installationthroughvesselmanwaystobesupp orted on full annular support they can also be suppliedas complete"Vane Packs"where thevanes areenclosed in aFramewhichis flanged for direct attachment to a"gas box".AlphaMIST VH-1-F Droplet SeparatorVane Mist 3 AlphaMIST DESIGN SHEETThe "VV" RangeThe AlphaMIST VV is an efficient styleof vanemist eliminator commonlyusedfor removing entrained liquidfrom vapour flowing vertically upwards,and for fouling services.