CFE Low Flow Rate TrialMass Balance

Mass Balance Error = Flow rate = Energy BalanceThe latent heat of vaporization at 100 C was calculated to be = 2257.10 Flow rate =

Then, sum these two values to find the total heat of water: = The heat of steam:

Error can be calculated:

The total heat input:

The overall heat transfer coefficient is equal to:

Where; Log mean temperature = 23.441 A= 0.018 m2 Q =

Using the same equation to find U2:A =0.061 m2Log mean temperature = 2.4 15840.626The steam economy:

For the condenser: 2376.86The sensible heat for the condenser is equal to:

The total heat input to the condenser:

The overall heat transfer coefficient is equal to:

Where; Log mean temperature = 42.302 A= 0.367 m2 Q =

FFE Low Flow Rate TrialMass Balance

Mass Balance Error = Energy BalanceThe latent heat of vaporization at 99 C was found to be = 2259.7

The overall heat transfer coefficient is equal to:

Where; Log mean temperature = 9.9 A= 0.165 m2 Q =

The steam economy:

For the condenser: 4753.7 The sensible heat for the condenser is equal to:

The total heat input:

The overall heat transfer coefficient is equal to:

Where; Log mean temperature = 35.71 A= 0.367 m2 Q =

CFE / FFE Low Flow Rate TrialMass Balance

Mass Balance Error = Energy BalanceThe latent heat of vaporization was found to be = 2255

For FFE side:

The overall heat transfer coefficient for CFE side is equal to:

Where; Log mean temperature = 37.12 A= 0.0164 m2 Q =

The heat transfer coefficient for the phase change is equal to:

Where; Log mean temperature = 8.9 A= 0.0626 m2 Q =

Total heat transfer coefficient:

Where; Log mean temperature = 8.9 A= 0.165 m2

The steam economy:

For the condenser: 7130.54 The sensible heat for the condenser is equal to:

The total heat input:

The overall heat transfer coefficient is equal to:

Where; Log mean temperature = 35.87 A= 0.367 m2 Q =

Discussion: For the climbing film evaporator, as the feed rate increases, the distillate, the concentrate and the steam rates increase. For the falling film evaporator, the distillate rate is not affected much and the concentrate rate increases. Steam economy is a measure of the efficiency of the evaporation system. The resulted calculations may show some inaccurate results due to some errors for the experiment procedure. By comparing the steam economy of each system, the efficiency will be evaluated. Since the larger flow of steam will produce a higher steam economy which means the lower efficiency of the system. The individual systems CFE and FFE are compared and based on the evaporation rate and steam economy, the FFE system showed a higher efficiency than the CFE system. A slightly difference in the evaporation rates which resulted in a small difference in the steam economy since more evaporation rate in the FFE system caused a lower steam economy. Therefore; the FFE system is considered as a slightly higher efficient than the CFE system. For the third run, the system is run in series. According to the calculated data, the system showed a much higher efficiency with a greater evaporation rate. Theoretically, the series system should provide a higher efficiency than running the CFF or FFE systems individually.