Condenser (Shell & Tube heat exchanger design)

[shankerm]

I need a carification on designing a condenser.

I've suceeded in developing a product on lab scale and I'am scaling it up into a 37 litre batch in a 100 litre jacketed vessel.

Now the solvent vapors (tetrahydrofuran) goes into the condenser and is reflxued back into the column. Vapors enter the condenser at 60 degree C.

Now I DONT KNOW HOW TO:

1) CALCULATE THE FLOW RATE OF VAPOURS ENTERING THE CONDENSER. In the 37 litre batch the quantity of THF is 15 kg. ?

2) Condensation temperatre of these vapors(thetrahydrofuran). ? The tube side is chilled water at 5 C and I'am assuming a rise of 5 C in temp of the chilled water.

Plese give me some tips on the design, And would the mechanical design vary in case the condenser is placed vertical ?

Thankyou!

 

[Montemayor]

Shank:

I'll assume you're a Chem Engineer and as such can appreciate that we can't calculate the vapor flow rate entering your reflux condenser either. You simply haven't given any basic data to design or calculate on. For example, we don't know if there is a reaction taking place. We also don't know how the THF solvent is found - in other words, are you adding it? Is it already present? At what pressure? Is any heat added to vaporize the THF? If you know the heat rate vaporizing the THF, you know the vapor rate generated and going into the condenser (if THF is the only vapor generated).

Designing a total condenser is not any easy job. Again, you have to furnish basic data:
- is the condenser vertical or horizontal?
- is the condensed product saturated or subcooled?
- is the process in the shellside?

For such small, lab quantities I have never calculated or designed the engineered size required. In these typical cases, one uses standard, pilot plant or lab equipment and you adapt it for your purpose. In this application you might be able to use nothing more complex than a copper coil in an overhead water tank. For such small quantities of THF you certainly can't justify a shell & tube TEMA design. This is a lab application and is handled with glassware or adapted, small, improvised equipment.

I would put something together and try it. If it works, fine; if it doesn't, modify it and try again.

I hope this helps you out.

Art Montemayor
Spring, TX