Fermenters oil flush

[gwapa]

Dear
This is a brewery. The vertical fermentation tanks have cooling jackets with vertical channels. The cooling system is overfeed with 4:1.The evaporation temperature in the separator tank -6 º C.
The jackets have a valve to drain the oil to a main tank
The oil in the jackets are drained during the Fermenter tank cleaning period (CIP). At this time inside the fermentation tank is 25 ° C. With this temperature begins to drain the jackets to the main oil tank which is at -6


It has been observed that the inner walls of the jacket is not properly drained and cause a delay in the production


The oil used is synthetic


Any idea how to inprove the oil drain from jackets ?
thanks

[NH3LVR]

I assume that this is an ammonia system.
My first question is why you have that much oil leaving the engine room in the first place. Or is it not draining? Do you have to add a lot of oil to the compressors?.

[PaulZ]

Hi gwapa
I am like NH3LVR, how much oil are the compressors using?
Is the receiver being drained?
Is the overfeed accumulator vessel being drained properly?
How has it been determined the inner walls are not draining properly?
If you can drain from the receiver and the accumulator vessels then the liquid going to the tank jackets should be fairly oil free.
With an internal tank temp of 25oC the oil should flow freely, you may have to leave draining for a longer period.
I would be trying to get the liquid NH3 as oil free as possible.
Regards
Paul

[gwapa]

HiNH3LVR / Paulz
Yes the system use ammonia as refrigerant
The personal of production alert that the fermentation period is longer that normal . That happen from time to time . The maintenance personnel flushing the jacket and the fermentetion period come ok .
In the brewery there are screw compressors (5000 Tr) which have oil separators .Also there are a huge oil separator for all compressors.
They also purge the ammonia separator from the overfeed system but even so the oil is carry over to the jackets
As I mentioned before the ammonia in the jacket is kept at -6ºC only at CIP period the temperature rise to 25ºC and they purge the jacket.


I am thinking that as they purge the jacket from 25ºC to -6ºC there are a high pressure loss and the ammonia liquid flows faster that the oil . In a period of time the temperature inside the jacket become again -6ºC and there are not pressure to purge the oil.


Do you think i must use hotgas to flush the jackets?
Regards
Gwapa

[RANGER1]

Gwapa as mentioned the pipe work detail on fermenters may not have oil drain in lowest suitable point to drain oil. This need to happen or oil becomes trapped.
Also big oil seperators mean nothing if they throw to much oil into system.
Assess oil consumption on each compressor & consider coalescer replacement to reduce the carry over
Coalescers can last from 1 year to 20 years!

[gwapa]

RANGER1
I agree with you but even new coalescers allows to pass 100 ppm of oil (mist) . This mist goes to the evaporators and part of those settle in fermenters jacket.
Beside change the coalescers the customer want to clean the jacket . Remember some hours loss in fermenter is a lot of production
I am looking a method to flush the jacket automatically
Regards
Gwapa

[Grizzly]

Hi gwapa.
Once cip has completed, how are the evaps /jackets then cooled back down?
Could you not consider modifying the oil drain.

With the huge temperature difs you have. I am not surprised that the coalescers are passing.

Secondly have you considered looking at what grade oil you are using. We changed a system from AP to POE.
With a huge improvement in oil carry over.
Grizzly

[gwapa]

Grizzly
They use syntetic oil. The compressor have coalecent filter and there is a huge post oil separator .The compressors discharge pass through this separator tank
Besides all of this oil goes to the fermenters jacket little by little and it produce a lag in bear producction
Gwapa

[RANGER1]

Dear
This is a brewery. The vertical fermentation tanks have cooling jackets with vertical channels. The cooling system is overfeed with 4:1.The evaporation temperature in the separator tank -6 º C.
The jackets have a valve to drain the oil to a main tank
The oil in the jackets are drained during the Fermenter tank cleaning period (CIP). At this time inside the fermentation tank is 25 ° C. With this temperature begins to drain the jackets to the main oil tank which is at -6


It has been observed that the inner walls of the jacket is not properly drained and cause a delay in the production


The oil used is synthetic


Any idea how to inprove the oil drain from jackets ?
thanks

Gwapa, can you post a picture of the jackets, how they are piped & oil drain connection?
The more detail the better to make a possible recommendation.

[RANGER1]

http://www.haphillips.com/uploads/files/FOS-11E-01.pdf

Never seen it used, but thought it might be interesting but in your case large scale.
100ppm is probably average these days, some manufacturers quoting 10ppm (hard to believe).
Oil vapour will pass through coalesces, so HA Phillips still would condense the vapour.

[gwapa]

Ranger1
Phillips oil separator are small . They are using two of 2500Tr each. Tne same concept but horizontal

Attached flow diagram
tcc.gif
Regards
GWAPA

[RANGER1]

Gwapa, the Phillips scrubber may be to small, but was showing a concept.

IN your schematic it's concept look ok as well, but is the oil drains on each liquid line in at the LOWEST possible point for gravity drain of oil?
CAn all of the oil drain away down the liquid line & not pool in pipe below CIP drain point below (sit on to of liquid line solenoid valve).

On bottom jacket I see a 1/2" drain valve, thought this maybe lowest point & 1 installed on each jacket?
Maybe manually drain it & see what you get out.
You could install hot gas & blow out with reverse flow, but if you do not have one nearby already it sounds expensive & not practical. You may disagree because of problems you are experiencing.

[gwapa]

Ranger1
thanks you I will make a test in one tank and keep all of you informed

Regards
gwapa