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View Full Version : Has anyone heard of the term "Brineing"? and not the secondary refrigerant like glyco







Chevy 383
25-09-2013, 08:13 AM
At a plant today and saw a vessel off the side of the pumped LP liquid line out to the rooms. Found out the designer/installer of the system and gave them a call and spoke to a guy involved with it and he gave me the run down on what it was. Very interesting to learn its called "Brineing" and its where the pumped LP liquid going out to a room thats is used as chiller is heated by the discharge gas to absorb sensible heat so that when it enters the evaporator its able to absorb latent heat early on in the evaporator to work as it should to create the refrigeration effect and not just flood the evaporator. If i have interpreted this wrong could someone try to explain it better please.:confused:

HVACRsaurus
25-09-2013, 11:21 AM
How is this chiller evaporator refrigerated?

Low temperature pumped liquid over feed with hand expansion?

I've heard of brineing - my interpretation is when the pump liquid doesn't expand through the regulating valve as it should (i.e. reg valve open too much) & just fills the evaporator coil with liquid refrigerant.

Say regular wet return from evaporator is 50/50 liquid/gas, a brined evaporator wet return may be 100% liquid..

NH3LVR
25-09-2013, 04:26 PM
There was a excellent articale published about this but I cannot by USIceman several years ago. I cannot locate it at the moment,but will look.
This si a response I wrote on another thread.
"Always glad to see another fish-freezing guy come along.
I am sure you have a pump system here, probably with centrifugal pumps.
Setting the overfeed ratio is a bit tricky, but not too critical. If your suction line is 3 degees warmer than the suction temp you are awful close to being on the money.
Setting the feed by superheat is not the way to go.
US Iceman has a lot of knowledge regarding overfeed rates, much more that I. The problem comes when the feed ratio is too high, causing a condition called brining.
Effectively you are injecting subcooled liquid into a evap. If the feed is too high under some circumstances the subcooled liquid will fill the evap for some distance before starting to boil away.
But it sounds like you are in good shape to me.
I might try changing feed rates on one freezer a bit to see if it makes any difference. I think you will find you about correct."
The paper is very interesting. I will look for it at home.

Grizzly
25-09-2013, 04:31 PM
Surely we are talking about a Brine tank system aka a flooded system.
Which usually has about 4 times the volume needed flowing to absorb heat.

Brine being Salty Water, which can be taken to very low temperatures without freezing.
So it's a concentrated salt to water solution.

The old 2nd world war Cold stores where I used to work.
Had the original Brine tanks in the Basement and a Huge Fan with ducts that blew air that had been cooled by the Brine solution.
The exact temps given. I cannot be more specific as this was way before even my time.

Maybe there are some with more grey hair than me that can explain further?
Grizzly

NH3LVR
26-09-2013, 01:36 AM
It is a flooded system I am sure. Mike Fisher wrote a excellent paper on brining but I had it on my older computer.
I looked around but did not find it on the net.
If you are feeding a medium temp flooded evaporator off of the same LPR as a low temp room you can lose a lot of effective coil surface, especially if it is a top feed style.

Chevy 383
26-09-2013, 08:29 AM
Sorry will be more specific about the plant. Its a pumped liquid over feed on hand expansions as you picked NH3LVR. IP taking care of glycol PHE, and pre cooling duties with a Frick TDSH233 sorting it via a Baltimore Evaporative Condenser (can't read the mod number). LP is done by a Mycom 250 VLD-B and is across the line to a similar Baltimore condenser. Liquid is direct into each pot from receiver, then pumped out to the rooms etc.So from LP pot its pumped out to rooms but has in parralel a heat exchanger that pumps in hot gas from discharge to warm the liquid up if the stores that are normally in freeze mode have been changed to run as a chiller because they hadn't piped IP over to that side of the stores. The more i think about it the more it makes sense as liquid out to room at -34c trying to evaporate at -10c has to absorb 24k before it starts to boil of so it would need a massive heat load in the room to work or as you say NH3LVR you would loose most if not all your coil surface as it would be fully flooded!

iBigChill
05-10-2013, 04:01 AM
Brining on a pump recirc system is used to refer to too much liquid going into a recirc coil and creating a super saturated condition that does not allow vapor to return to the recirculator vessel. You should aim for a hxv setting just at saturated under normal load backed down a quarter turn. Generally recirc is 3:1 or 4:1. Key is you have a saturated condition with a fully wetted coil.

RANGER1
05-10-2013, 08:00 AM
We looked after a major cold store company, who's national engineer insisted on opening all reg valves fully.
We tried to explain system not designed to operate like that, he obviously took offence & got shafted.
Plant somehow could achieve temps
Plate freezers also have over 20 to 1 & work too!

Segei
05-10-2013, 06:19 PM
We looked after a major cold store company, who's national engineer insisted on opening all reg valves fully.
We tried to explain system not designed to operate like that, he obviously took offence & got shafted.
Plant somehow could achieve temps
Plate freezers also have over 20 to 1 & work too!
Temperature can be achieved but it is not energy efficient operation. If plant has reserve of evaporator surface or it run at lower suction pressure, temperature can be achieved but energy will be wasted.

RANGER1
05-10-2013, 10:38 PM
Temperature can be achieved but it is not energy efficient operation. If plant has reserve of evaporator surface or it run at lower suction pressure, temperature can be achieved but energy will be wasted.

Certainly not disagreeing & it's not what the air coolers are designed to do.
Would it be correct to say that a flooded unit with a surge drum on top, only has the circuits different?