3 replies to this topic

[sskumar]

I have a problem on hand. Any body's help will be highly appreciated

Problem:
We have Hydrogen Sulfide(H2S) generation plant. Generated H2S (@ 200 Kg/Hr.) is compressed from 1.2 atm g to 19-20 atm g to feed it into the Purge Tower of Main Unit. (Purge Tower is at pressure of 16-17 atm g). For this pupose we use 3 stage reciprocating compressor. I thought of a method to charge this gas from H2S generation plant to Main Unit without this compressor, thereby saving the energy cost of compressor.

In Main Unit, we have feed stream at a pressure of 28-30 atm g, This feed stream goes to purge tower, which is operated at 16-17 atm g. There is an LCV on this feed stream, which controls the level of purge tower. Hence there is 12-13 atm pressure drop across this control valve. I want to take advantage of this pressure drop and an eductor to charge H2S gas to Purge Tower. I want to provide the eductor across the LCV using the feed stream as power fluid. H2S gas dissolves immediately in the feed stream.

I want some help in the design of eductor for the above system. The following are the conditions:

Power fluid inlet pressure is 28-30 atm g, temp=30degC, density~1gr/cc
Power fluid outlet pressure is 16.5-17.5atm g
H2S gas pressure at the inlet to eductor is 0.6-0.7 atm g, temp is 30 degC
Throat pressure can be 0.3-0.4 atm g
I searched internet, books for the design but I did not find any. Can any body suggest me how to design or the web address where I can found some information, for which I will be very much thankful.
Regards
sskumar

[mbeychok]

sskumar:

The design of eductors and ejectors is quite complex and requires a wealth of experience ... it is not a job for beginners. The best approach is to purchase your eductor from one of the major manufacturers of such equipment ... for example:

(1) The Graham Company at www.graham-mfg.com
(2) The Croll Company at www.croll.com

Don't try designing it yourself.

[djack77494]

sskumar:
I agree with Milton. It would be an unrewarding experience to try to design an eductor, and, even if you did, it would not be economically attractive to have your design implemented. Instead, you want to purchase an eductor from a manufacturer.

Some time ago, I used eductor sizing software from Croll-Reynolds. I found the software to be powerful and very useful, and would recommend that you pursue a similar approach in your endeavors.

Good luck,
Doug

[BaneAUS]

Here's another company you might want to look at for eductor design.

http://www.1877eductors.com/index.html

http://www.1877educt...quids_V2010.pdf

I was able to get a reasonable estimate for a liquid/gas eductor that we use in Induced Gas Flotation Units. If you look at this website they have a wealth on information on different types of eductor and there applications.

I still went to Penbertly and Mazzei for the final design, but at lease this let me size associated valves while waiting for the vendors.