Air purger

[Romanicus]

Hi,

I want to ask you if you think is absolutely necessary an automatic air purger for an ammonia plant running -30/ + 35. At -30 C the pressure is around 1.2 bar, so no risk of air entering in the instalation.
I think is no need for this air purger.

What do you think?
Thanks.

[Sandro Baptista]

It depends on how much do you want / could spend.

Probably sometimes you will run at -35ºC, no? Or during some service always some air enter.

However I confess that I wouldn't put it unless the Client wants it.

[Magoo]

Hi.
your suction at 1.2 bar absolute is a bees **** above zero. So seriously concider an auto purger to keep system clean and tidy. Or else do a high side purge six monthly.

[Josip]

Hi, Romanicus

Hi,

I want to ask you if you think is absolutely necessary an automatic air purger for an ammonia plant running -30/ + 35. At -30 C the pressure is around 1.2 bar, so no risk of air entering in the instalation.
I think is no need for this air purger.

What do you think?
Thanks.

No need for automatic purger (it will be better to have it, less headache regarding purging), but for sure you need to provide valves for proper manual purging from time to time ...

One question, of course if you want to share that info with us ... which compressors you have installed, condenser/s etc.. ..... assume it is single stage plant ....

Best regards, Josip

[Romanicus]

Hi again, and thanks for the responses.

No compressors yet installed.
It's a tender book. I will go with 2 screws with economizer, VSD driven each, pumped ammonia, all evaporators with hot gas defrost, evaporative condenser.
It's a logistic center. In the tender it's specified that you must have this automatic air purger, but i'm afraid that my competition will not offer it. I will offer it, because the tender asks for that, but i want to discuss with the client and maybe he will agree not to have it (if he pushes me with the price down)
It's a one stage plant. I agree with you that it's nice to have an automatic air purger, but it costs quite a lot.
For sure, if the client agrees not to have this automatic air purger i will install manual purging system.

For Sandro: In normal operation is not possible to run at -35C. All the rooms are -20C rooms. BUT, the client might want to store ice cream or something like that, in this case, yes, it's possible to run at a lower suction temperature. But again, the tender specifies -28 evap, -20 air inlet in the evaporator.

Till now the score is 3-1 against the automatic air purger

All the best,
Andrei

[Sandro Baptista]

Hi again, and thanks for the responses.

No compressors yet installed.
It's a tender book. I will go with 2 screws with economizer, VSD driven each, pumped ammonia, all evaporators with hot gas defrost, evaporative condenser.
It's a logistic center. In the tender it's specified that you must have this automatic air purger, but i'm afraid that my competition will not offer it. I will offer it, because the tender asks for that, but i want to discuss with the client and maybe he will agree not to have it (if he pushes me with the price down)
It's a one stage plant. I agree with you that it's nice to have an automatic air purger, but it costs quite a lot.
For sure, if the client agrees not to have this automatic air purger i will install manual purging system.

For Sandro: In normal operation is not possible to run at -35C. All the rooms are -20C rooms. BUT, the client might want to store ice cream or something like that, in this case, yes, it's possible to run at a lower suction temperature. But again, the tender specifies -28 evap, -20 air inlet in the evaporator.

Till now the score is 3-1 against the automatic air purger

All the best,
Andrei

My advice if you are in doubt: give the price for the air purger separated from the rest of the plant and let the Client decide.

[brian_chapin]

My advice if you are in doubt: give the price for the air purger separated from the rest of the plant and let the Client decide.

Exactly right.

[taz24]

Hi again, and thanks for the responses.

No compressors yet installed.
It's a tender book. I will go with 2 screws with economizer, VSD driven each, pumped ammonia, all evaporators with hot gas defrost, evaporative condenser.
It's a logistic center. In the tender it's specified that you must have this automatic air purger, but i'm afraid that my competition will not offer it. I will offer it, because the tender asks for that, but i want to discuss with the client and maybe he will agree not to have it (if he pushes me with the price down)
It's a one stage plant. I agree with you that it's nice to have an automatic air purger, but it costs quite a lot.
For sure, if the client agrees not to have this automatic air purger i will install manual purging system.

For Sandro: In normal operation is not possible to run at -35C. All the rooms are -20C rooms. BUT, the client might want to store ice cream or something like that, in this case, yes, it's possible to run at a lower suction temperature. But again, the tender specifies -28 evap, -20 air inlet in the evaporator.

Till now the score is 3-1 against the automatic air purger

All the best,
Andrei

You do not have to have one so that is 4 - 1 against, but

My advice if you are in doubt: give the price for the air purger separated from the rest of the plant and let the Client decide.

Is very sound advice and that is what I would do.

taz

.

[Romanicus]

Thank you gentlemen. In the tender the air purger has a separate price, and so it will have in my offer. Thanks for the nice advices. Tommorow I have to issue the offer so keep the fingers cross for me
Have a wonderful evening.

[Sandro Baptista]

Hope you can do the business unless you are from my competitor . Surely not my company only operate in Portugal.

All the best