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Distillation Heat Analysis. ENCH 435 September 20, 2005 Jason Hixson Michael Hickey Don Scott. CW out. Condenser. CW in. Reflux. Trays 1-6. Feed. Trays 7-12. Reboiler. Q Heater. Calibrations.
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Distillation Heat Analysis ENCH 435 September 20, 2005 Jason Hixson Michael Hickey Don Scott
CW out Condenser CW in Reflux Trays 1-6 Feed Trays7-12 Reboiler QHeater
Calibrations All thermometers were calibrated by plotting known temperatures (ambient air, boiling point of water, and the boiling point of methanol) to those read by each thermometer. The equation of best fit was then used to correct measured temperature values.
Setup • Each liquid was heated to boiling point and allowed to cool to room temperature. • The temperature was then measured over an extended length of time.
Analysis • Calculation of the overall heat transfer coefficient, U, was done using the following equation. TR(0) =Reboiler Temp at time=0 TA = Ambient Temperature TR =Reboiler Temp at time=t • Using this equation as a model we were able to fit U to best fit our data range. Column Reboiler TA A TR, m, Cp
Column Losses • The losses from the column can be grouped into three sections: -Trays -Feed -Reflux • These were found using the same method shown in the reboiler analysis.
The System • Heat losses can be found using the following equation: QL=UAΔT • Losses will be assumed to only occur throughout the reboiler and column. We will also have heat transferred through the condenser. • If all analysis is correct then we should have the following: QHeater-QCondenser=ΣQL
Condenser Q=m*Cp*ΔT Q=UA ΔTLM Estimated A= 1325 cm2 WaterMethanol Q=1.13 kW Q=0.88 kW M1, T2 M1, T1
Water Methanol CW out QCondenser= 1.13 kW 83 kW Condenser CW in Reflux QReflux= 95 W 52 W Trays 1-6 QTrays 1-6=156 W 102 W QJoint= 42 W 52 W Feed QFeed= 69 W 17 W QJoint= 42 W 52 W QTrays 7-12=156 W 102 W Trays7-12 QHeater Reboiler QReboiler =300 W 120 W
Total System Losses Water QL=880 W $Loss=23.39 per month Methanol QL=497 W $Loss=13.29 per month Losses based on continuous run.