2 replies to this topic

[hiren_d]

Dear all,

 

I am involved in designing vacuum catch pot to be installed in between batch distillation system(inclusing reactor, HEs, reflux pot , receivers etc.) & vacuum pump, to achieve reduction in solvent vapor going to vacuum pump.

 

I have read in the book "Rules of thumb" that such catch pots are jackettted having tangential entry & demister pad on top.

 

I have doubt that -

 

1)there will be vacuum drop due to tangential entry of vapor into catch pot .

 

2)demister will have some pressure drop which will result in poor vacuum at source.

 

Can anyone suggest me how to do process design of such catch pot?

 

system volume : 10 M3

 

Vacuum requirement: 40 torr during initial stage of distillation & full vacuum during Final degassing.

 

Vacuum pump:   Once through oil lubrication rotary vane type(250 M3/Hr, 1 torr(g))

Vacuum: 1 torr(g) at vacuum pump 

               5 torr(g) at reactor 

Solvent being distilled : Multiple solvents ( MeOH, EtOH,IPA, Methayl acetate,Ethyl acetate etc.)

 

Attachement:  Vacuum catch pot schematic drawing for understanding & betterment if any.

 

Regards,

 

Hiren Dave

 

 Vacuum catch pot schematic.pdf   37.91KB   78 downloads

 

[breizh]

Hi ,

Use the search engine in this forum , a lot of document are available about gaz liquid separator . I'm surprised to see that your catch pot pot is equipped with a jacket . Normally condenser should be installed to prevent solvent carry over .

My view.

 

Breizh

[hiren_d]

Hi Mr.Brizh,

 

Thanks for prompt response.

 

Here in india normal temperature lies between 30-35 C. To reduce vaporaization at this temperature jacket is provided to the catch pot.

Cost of additional condenser & space occupancy will also be constraints.

 

Besides this ,also batch distillation set up already contains two condenser in series (Primary with cooling /chilled water, Secondary with chilled brine as tube side utility).

Even after that the solvents gets carried over into vacuum pump & contaminate lubricating oil.

 

If we put catch pot with jacket , it will have two advantages:

 

1)Recover more sovent (about 5% more than system without catch pot) 

2)Reduction in vacuum pump breakdown due to solvent contamination.

 

Regards,

Hiren Dave