3 replies to this topic

[ramnathsharma]

Dear Freinds,

We used to pump Di ethyl Ether through Centrifugal pump and found 2-3 % loss of ether through vent line .

Now we want to pump Ether under nitrogen pressure, hope loss will be minimised!!!!

I still believe that loss will be there !!!

Any ideas / suggestions / previous experiences particularly " Pumping under Nitrogen Pressure"

Thanks & Regards

Ramnathsharma

[empower70]

Dear Freinds,

We used to pump Di ethyl Ether through Centrifugal pump and found 2-3 % loss of ether through vent line .

Now we want to pump Ether under nitrogen pressure, hope loss will be minimised!!!!

I still believe that loss will be there !!!

Any ideas / suggestions / previous experiences particularly " Pumping under Nitrogen Pressure"

Thanks & Regards

Ramnathsharma

Sharmaji,
Pls. share P&ID of the existing system, with process parameters like P, T, vapor pressure.Also, show particular places u have checked for leakages like vent.
Hope u have used existing pump with double mech. seal.

[Andrei]

ramnathsharma,

What you intend to do I think it is called nitrogen blanketing. I am assuming you are pumping in a vessel, and the loss is through the vessel's vent line.
You should eliminate the loss by maintaining the nitrogen (or other compatible gas) blanketing at a pressure just above the vapor pressure of the liquid at your maximum liquid or storage temperature, whichever is greater.
I've looked for the vapor pressure for Diethyl Ether; it is just above atmospheric pressure at 35 ºC. So, if your liquid reaches this temperature, or even lower depending on the barometric pressure at your location, it will be vaporized.
It is common practice to use inert blanketing for storage of high volatility liquids.
You should be careful though, your vessel should withstand the new operating pressure.
Another thing that you can do is to subcool the liquid.

[Qalander (Chem)]

ramnathsharma,

What you intend to do I think it is called nitrogen blanketing. I am assuming you are pumping in a vessel, and the loss is through the vessel's vent line.
You should eliminate the loss by maintaining the nitrogen (or other compatible gas) blanketing at a pressure just above the vapor pressure of the liquid at your maximum liquid or storage temperature, whichever is greater.
I've looked for the vapor pressure for Diethyl Ether; it is just above atmospheric pressure at 35 ºC. So, if your liquid reaches this temperature, or even lower depending on the barometric pressure at your location, it will be vaporized.
It is common practice to use inert blanketing for storage of high volatility liquids.
You should be careful though, your vessel should withstand the new operating pressure.
Another thing that you can do is to subcool the liquid.

Dear ramnathsharma hell,
Although Andrei's responses are so helping and positively phrased that I deeply like his reply.
A very tiny addition that if you resort to subcooling finally as per his advice; then in addition to appropriate blanketting adequate insulation must not be forgotten
if exposure to ambient conditions is harsh(high temperatures)
Best Regards
Qalander