Michael R. Resetarits Forum Moderator 22 Posts
Re: Solving Problems with Vacuum Distillation Systems13 April 2009 at 1:29pm
This is a bit out of my area, but here are my thoughts:
1.) If I did the calculation correct, I calculate the unit is generating 1,108 ACFM (air + carry-over) at 60F and 0.4 Torr. (This ACFM calculation needs confirmed.) The calculated ACFM is greater than the stated capacity of the vacuum system given as 570 ACFM. If the temperature is lower than 60 F, the volume would be less but I doubt it is low enough to reduce the ACFM to half and if the temperature is greater than 60 F the ACFM would be higher. If the gas/vapor load on the vacuum system is not the problem or the whole problem, and it may not be since the pressure is 0.4 Torr at the pump, then in addition to vacuum system load evaluation the other equipment in the system needs its pressure drop evaluated.
2.) I don't know the equipment arrangement, but if I assume that the vacuum is being drawn through the overhead condenser and that the distillation column is between the reactor and vacuum system then the pressure drop of various components need to be evaluated. Some of the components may be a packed or trayed tower, overhead condenser and the connecting piping.
If you already considered these possibilities, you may want to contact a distillation consultant.
Avinash Patil Community Member 4 Posts
Re: Solving Problems with Vacuum Distillation Systems3 October 2012 at 12:30am Last edited: 4 October 2012 at 8:48amProblem seems to be with column internals. pressure drop of 8-.4 torr=7.6 is abnormal. Vaccum pump seems ok as it is delivering 0.4 torr