6 replies to this topic

[push121072]

what will happen if we change the feed tray position in the distillation column ,if all other operation parameter remain constant .???

plz give the ans in the following references..

 

1-distillate composition 

2-bottom composition 

3-heat duty of reboiler and condenser 

[fallah]

Hi,

 

Generally speaking, if the feed enters in higher tray the light components concentrations in overhead will be increased and in bottom outlet will be decreased; heat duty of reboiler and condenser will be increased. If the feed enters in lower tray all mentioned changes will be performed vice versa...

[push121072]

sir.

can you explain the above statement at the microscopic level ....

 

because as far as my knowledge if u increase the lenght of the rectifying  section (i mean feed is supplied at lower plate) the purity of light component in increased in overhead product .and decreased in bottom product.

[fallah]

 Hi,

 

 

Please read the conclusion of section "Effect of Feed Tray Position" included in following link:

 

http://lorien.ncl.ac.../dist-trays.htm

 

 Of course, the study has been performed in fixed reboiler and condenser rates...

 

Hope it helps you out... 

[push121072]

sir can you give  me the explanation of the above link ...

why this is happening.???

[fallah]

sir can you give  me the explanation of the above link ...

why this is happening.???

 

Hi,

 

The statement i did refer in the link is as follows:

 

"...As the feed stage is moved lower down the column, the top composition becomes less rich in the more volatile component while the bottoms contains more of the more volatile component...."

[push121072]

"...As the feed stage is moved lower down the column, the top composition becomes less rich in the more volatile component while the bottoms contains more of the more volatile component...."

 

its ok.

 my question is that why this is happening and what is reason behind it..

           Can you elaborate it at the microscopic level ..

Edited by push121072, 13 October 2013 - 02:16 PM.