Column Tag No.:HCL Scrubber Job No.:4506A Client :JOLProject :SR - Plant -4, 5Input DataStream:HCL Vap.Packing type =Intallox Saddles Packing size =25mm Packing MOC=PP Gas pr. Drop / m bed =15mmWC / m packing height =147.1(N/m 2)/mTotal packing height= 3.2m (including all packed beds)Gas / Vapour Properties Gas / Air flow rate =OR0m 3/h == 0m 3/sGas pressure at entry = 1.0000atmGas temperature at entry =30.00oC =303.00oKGas / Air mol weight=29Component to be scrubbed Component Name =HCL VapComponent flow rate =70Kg/h % comp. in air/gas =6% (v/v)Molecular weight of comp.=36.53Conversion :Liquid Viscosity, µL =0.0035000Ns/m 2 3.5C p =Ns/m 2Packing factor, F p=21m -1Charac. Packing Factor,C f =33 Ref. Table 6.3, Characterstics of Random packingsConversion factor, J = 1.0factor for adequate liquid distribution & irrigation across the bedSCRUBBER DESIGN (PACKED COLUMN)0.00350000CalculationsSince larger flow quantities are at the bottom for an absorber, the diameter will be chosen to accommodate the bottom conditions.To calculate Gas density Avg. molecular weight =29.45Kg / KmolSelect vol. flow rate and mass flow rate from above,Selected mass flow rate =0.277778Kg/sSelected vol. Flow rate =0.234499m 3/s Selected molar flow rate =0.009432Kmol/s Therefore, gas density=1.1846Kg/m 3(mass flow rate / vol. Flow rate)To find L', G' and Tower c/s areaAssuming essentially complete absorbtion, Component removed =0.0207Kg/s (molar flow rate x % comp. x mol. Wt.)Liquid leaving =0.0420Kg/s (Inlet liquid flow rate + comp. Removed)0.5=0.00497Using0.00497as ordinate, Refer fig.6.34 using a gas pressure drop of 147.1(N/m 2)/mG' 2 C f µL 0.1 J =0.04 (from graph)G ) g c Therefore, G'=0.5=1.6665Kg / m 2.s Tower c/s area =0.1667m2( c/s area = mass flow rate / G' )Tower diameter=0.4607m =460.7mm=500mm Corresponding c/s area=0.1963m 2TO CALCULATE COLUMN DIAMETEREfficiency of fan / blower=60%To calculate pressure drop Pressure drop for irrigated =470.72N/m 2(pressure drop per m packing x total ht. of packing)packingFor dry packing,O/L Gas flow rate, G'=2.s (Gas inlet flow rate - Component removed) / c/s areaO/L Gas pressure=2(subtracting pressure drop across packing)= gas mol wt. x 273 x gas o/l pr. 22.41m3/Kmol T in kelvin 101330=C D =96.7 Ref. Table 6.3, Characterstics of Random packingsDelta P = Z=2Pressure drop for packing =613.61N/m 2(irrigated packing + dry packing)Pressure drop for internals =25mmWC(packing supports and liquid distributors)=245.17N/m2Gas velocity=7.5m/sInlet expansion & outlet = 1.5 x Velocity heads = 1.5 x (V 2/ 2g)contraction losses=42.19N m / Kg=49.97N/m 2(divide by density)Total pressure drop =908.75N/m2(packing + internals + losses)Fan power output=pressure drop,N/m 2 x (gas in - component removed) Kg/sO/L gas density, Kg/m 3=201.35N .m / s =0.20kW Power for fan motor=0.34kW (fan power output / motor efficiency)=0.45hpTO ESTIMATE POWER REQUIREMENTLiq.-Vap. Flow factor, F LV==Design for an initial pressure drop of15mm H2O /m packingFrom K 4v/s F LV ,K 4=0.85K 4 at flooding =6.50Trial % flooding==Gas mass flow rate, V m==3.7763kg/m 2.s Trial column c/s area=V / V m (Trial A s )=0.0736m 2Trial column dia., D =0.3060mD = (4/pi) x Trial A sRound off 'D' to nearest standard size Therefore, D =0.500mColumn C/S area, A s=0.1963m2A s =(pi/4) x D2% flooding =13.5472% flooding = Trial % flooding x (Trial A s / A s )ConclusionGenerally packed towers are designed for 50% -- 85% flooding.If flooding is to be reduced,(i) Select larger packing size and repeat the above steps.OR(ii) Increase the column diameter and repeat the above steps.COLUMN DIAMETER / HYDRAULIC CHECK(1/2)Input Data 0.018 N/m =dyne/cm Liquid-phase Surface Tension, =20dyne/cm Liquid Viscosity = 3.5cP n=1.13080Calculation ln HETP =0.837437HETP==For separations, less than 15 theoritical stages, a 20% design safety factor can be applied.Considering 20% safety factor, HETP =0.845065mFor separations, requiring 15 to 25 theoritical stages, a 15% design safety factor can be applied.HETP =HETP PREDICTIONNorton's Correlation Applicable Norton's Correlation NOT applicable18。