Oil removal from Ammonia plant

[psrao]

Hi Friends,

I have a doubt in the procedure of oil removal from Ammonia plant. Normally we remove accumulated oil from Evaporator periodically to maintain the heat transfer efficiency. Is there any system to send it back to the compressor, if it is there is it advisable to do so. Otherwise will be there any problem with oil quality.

Thanks and regards,
psrao

[ernestlin]

Could you change your font size?? It's hardly seen.

[lana]

Hi there,
I am not an expert in ammonia but as far as I know the oil is drained from the bottom of the receiver and the seperators. So there would be very little oil in the evaporators and this will be removed during hot gas defrost and back to the seperators.
On this subject USIceman can help you a lot.
Also I would be waiting for his responce.
Cheers

[faryuki]

sorry, the evaporator is unit cooler or PHE or unit cooler use surge drum?
yes, oil will be accumulate at down stream for make heat transfer efficiency at evaporator you have to drain the oil at separator or make drain valve at evaporator....
happy working

[US Iceman]

Is there any system to send it back to the compressor, if it is there is it advisable to do so. Otherwise will be there any problem with oil quality.

I have seen several systems where an oil reclaim system was built. They are not factory assembled, but rather built in the field by the contractors.

To recover oil you have several problem areas:

1. boiling off the liquid ammonia
2. warming the oil up (ease of transfer & ensures refrigerant is boiled off)
3. pumping the oil for the transfer to the compressor
4. filtering the oil before it is returned to the compressor

Basically what you need is a heated oil distillation tank, oil pump, and high quality filter. The filter is VERY important because the oil picks up a lot of junk in the system, so you want to make sure it is clean before you pump it back into the compressor.

The oil filter should be at least an 8 micron oil filter with a LOT of surface area to allow longer periods of operation.

PS. Thank you lana.

[lana]

Dear Psrao,

I told you ......

Cheers

[Josip]

Hi, Psrao

I have seen several systems where an oil reclaim system was built. They are not factory assembled, but rather built in the field by the contractors.

To recover oil you have several problem areas:

1. boiling off the liquid ammonia
2. warming the oil up (ease of transfer & ensures refrigerant is boiled off)
3. pumping the oil for the transfer to the compressor
4. filtering the oil before it is returned to the compressor

Basically what you need is a heated oil distillation tank, oil pump, and high quality filter. The filter is VERY important because the oil picks up a lot of junk in the system, so you want to make sure it is clean before you pump it back into the compressor.

The oil filter should be at least an 8 micron oil filter with a LOT of surface area to allow longer periods of operation.

PS. Thank you lana.

Agree with all said. It is too expensive and I will think twice (even more times) before attempting to install oil reclaim system.

In other hand if you have good oil separators your oil loss will be negligible and better to add new oil.

One positive thing about such a system is easy changing of oil and that one (if you have more units) I will suggest you to install it, not to expensive but very useful.

Best regards, Josip