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[Valentino111]

Hi Everyone,

 

Maybe you could consider this problem as very basic but I am finding myself struggling with coming up with what I think the prediction should be. 

 

I have got a semi batch/batch operation, in this operation initially I collect 1000 L water at 30C and once collected I start feeding in water at 83C at a rake of 31.1L/min to make up to 7000L and I am struggling to come up with a formula which will tell me how the temperature will increase as I am adding the water.

 

this was the initial approach based on calorimetry to determine the final temperature: Q(loss) = Q(gain)  

 

Now I expect that after using or deriving an integral equation from the energy balance I should get a value which is close to the value which I obtain from the above equation of which I do not. As when I attempt to draw a graph to show how the temperature will increase it becomes linear of which i dont think it should be.

 

The vessel is a 10000L stainless steel vessel which is split jacketed horizontally one side for the hot liquid and the other for the steam and is insulated. It has a bottom mounted stirrer. The reason for wanting to obtain this temperature distribution is cause I am attempting to optimize a process which I consider to be energy inefficient. 

 

One the spread sheet you find the equation which I derived from the energy balance, Just the Q in the equation am I correct to calculate it as the convective heat transfer for the liquid.

 

 

Some guidance will be appreciated thank you.

 Modelling Mixing Vessel.xlsx   24.4KB   2 downloads

Edited by Valentino111, 21 November 2017 - 06:36 AM.