Filtration and Cold Storage Calculations

FILTRATION AND COLD STORAGE CALCULATIONS
İSMAİL GENÇ
—Filtration is made to remove the suspended pectin residues inside of the juice for clarification
—Pectinase is used for break down of the pectins for clarification
α-(1-4)-linked D-galacturonic acid
(PECTIN)
—Feed Rate= 1600 kg/h*(1m3/1050 kg)= 1.49 m3/h
—CS= Mass of solids deposited on the medium per unit volume of filtrate
—CS=(32 kg/h)/(1.49 m3/h)= 21.47 kg solid/ m3 filtrate
—Operation time= 1h =3600 sec
—Operation pressure= 5 bar =5*105 Pa
—Assume radius of one plate = 0.25 m
—Area of one plate= π* (0.25 m)2 = 0.196m2
—If the volume of filtrate versus time per volume of filtrate graph is plotted according to the filtration data, intercept point will give B and slope will give Kp/2
—KP=
—Where;
—µ: Viscosity in Pa*s
—α: Specific cake resistance
—CS: Mass of solids deposited on the medium per unit of volume of filtrate
—A: Area of one plate
—∆P: Pressure drop in Pa
B=
—Where;
—Rm: Medium Resistance
—By using the data of filtration including the volume of filtrate and time period to collect that filtrate; graph is plotted to obtain the specific cake resistance and medium resistance
—µ= 5.24*10-3 Pa.s
—Equation of line : y = 0,106x + 1,308
—Slope =0.106*106 s/m6 =KP/2
—KP=212000 s/m6
—KP=
—α = 5.81*1011
—B=
—Rm= 97975.2 m-1
—Where;
—t: time of operation in seconds
—V: volume of filtrate for operation time in m3
—A= 6.32 m2 which is total required filtration area
—Number of plates= Total area/Area of one plate
=32.24 plates
—33 plates can be used for this operation
—Power required=3.345 kW
—Feed Rate= 1200 kg/h*(1m3/1061 kg)= 1.11 m3/h
—CS=21.62 kg solid/ m3 filtrate
—Operation time= 1h =3600 sec
—Operation pressure= 5 bar =5*105 Pa
—Assume radius of one plate = 0.25 m
—Area of one plate= π* (0.25 m)2 = 0.196m2
—µ= 6.58*10-3 Pa.s
—Equation of line : y = 0,210x + 1,83
—Slope =0.210*106 s/m6 =KP/2
—KP=420000s/m6
—KP=
—α = 9.09*1011
—B=
—Rm= 109160.3 m-1
—A= 6.64 m2 which is total required filtration area
—Number of plates= Total area/Area of one plate
— = 33.87 plates
—34 plates can be used for this operation
—Cold Storage Calculations
—Product storage in barrels
—Barrel capacity=250 lt
—392 kg pekmez production /h
—Assume 30 days for transportation
—392 kg pekmez/h*24h/day*30 days= 282240 kg maximum product storage should be mentioned.
—282240 kg/(250 kg/barrel)=1129 barrels should be stored
—1129barrels*250 lt=307250 about 307 m3 storage area required for product.
—If we think about the space between barrels and movement spaces
—Storage volume should be approximately 500 m3
—Product temperature = 25 ˚C
—Storage temperature= 5 ˚C
—Average temperature for a year in Kilis= 17 ˚C
—Dimensions of the storage room= 5*10*10 = 500 m3
—According to the knowledge from Food Engineering Operations book, heat load from all causes other than heat generation, wall leakage and miscellaneous losses can be taken as approximately 0.003*V0.6 kj/s for each ˚C difference between the storage temperature and the outside temperature under standard storage conditions where V is the volume of the storage room in m3.
—Conventional British practice leads to wall leakages of about 7-8 W/m2
Heat Losses
*Heat of product
*Wall Leakage
*Miscellaneous load
*Heat load from other causes such as from walls, roof, floor etc. which are related with the transfer between the storage room and the outside.
Heat of product
392 kg/h* 24h = 9408 kg for one day
Cp of pekmez =4.18*Xwater+2.5*Xsugar (kj/kg.K)
=4.18*0.28 + 2.5*0.72
=2.97 kj/kg.K
Qproduct=392 kg / h* (1h/3600s) *(2.97 kj/kg.K)*(25-5)K
=6.47 kW
—Wall leakage
—Area of walls= 4*5*10+10*10= 300 m2
—Wall leakages= 7-8 W/ m2
— =8 W/ m2*300 m2
— =2.4 kW
—Miscellaneous Load
—Qforklift=500W*10 =5kW
—QWorker=20* 270W=5.4 kW
—Qlights=8*36 W=288 W for 4 hours of light opening= 1.15 kW
—Qml=5+5.4+1.15=11.55 kW
—Heat loss by other effects
—Qother=0.003*V0.6
— =0.003*(500)0.6 =0.125 kW for each ˚C difference
—12 ˚C difference
—Qother=12*1.15 kW= 1.5 kW
—Total loss=6.47+2.4+11.55+1.5
— =21.92 Kw
—Apply 10% safety: 21.92 *1.1= 24.1 kW

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