4 replies to this topic

[ali]

hi dear friends,
I have observed a safety valve on pressure boost section of a diffuser in first stage of a two stage ejector. The shell side condensor of this ejector has vauum pressure. This safety valve isn't observed always on ejectors, even though the produced vacuum by those ejector may be the same. please explain me about the reason for including this safety valve.
thanks

[paulo]

Dear Ali

Can you please be a little more clear? Can you describe the application?
Steam jet vacuum systems do not need a safety valve most of the times.
Some applications like steam jet vacuum systems for turbine surface condensers may have a safety valve installed at the intercondenser, but this is a specific case.

Paulo

[ali]

Dear Ali

Can you please be a little more clear? Can you describe the application?
Steam jet vacuum systems do not need a safety valve most of the times.
Some applications like steam jet vacuum systems for turbine surface condensers may have a safety valve installed at the intercondenser, but this is a specific case.

Paulo

In the two stage ejector, on the end of diverging section of diffuser, I have observed the safety valve. the set pressure for ejector is 3.5 bar. It should be pointed out that the maximum allowable pressure for shell side of the intercondenser is also 3.5 bar.

thanks

[djack77494]

Ali,
You have correctly observed that a safety valve (PSV) is not always associated with the intercondenser portion of a vacuum system. In your system, a PSV has been installed - presumably for good reason. IF you have a scenario where you can overpressure the equipment between the first and second stages (or anywhere else for that matter), then you need to circumvent this problem. Oftentimes, the solution is to add a PSV. I suspect that your predecessors foresaw a situation where the outlet path could be blocked. Again, guessing that the motive steam pressure is above the intercondenser design pressure of 3.5barg, they sought to protect the intercondenser from the scenario and therefore added a PSV. Assuming that the scenario is not totally ridiculous, so their approach is quite sensible.
Doug

Hi all,

I am trying to design an ejector where both my motive fluid and suction fluid are low temperature gases. Can any one please help me in the designing of it. Possibly can I get the relations or equations used in an excel file. My email id is malayanath-jeedi@utulsa.edu

Thanks.

Jeedi.