PDA

View Full Version : Brine



chillyblue
26-05-2007, 05:08 PM
What specific gravity should i have if i have a system evaporating at -35C to get brine down to -25C.

US Iceman
26-05-2007, 06:54 PM
If you will be more specific on the type of brine you want to use then someone can develop an answer for you.

Another possible question might also be; Is the piping exposed to lower temperatures during shut down conditions, say winter ambient temperatures?

The operating temperature is only one point where the freezing temperature of the brine needs to be considered.

chillyblue
26-05-2007, 08:15 PM
Thanks!!

The salt used is Calcium chloride.
The system is a tank full of a water and calcium chloride brine mix, the mixture is circulated by a aggitator, the refrigeration evaporator is submersed in the mixture to cool it, the customer requires the mixture to be -25C

Thanks for your response

US Iceman
26-05-2007, 09:00 PM
A solution of 29% calcium chloride (by mass) will provide a -45°F (-42.78°C) freezing temperature of the brine. At this solution, the specific gravity is about 1.296.

chillyblue
27-05-2007, 02:03 PM
A solution of 29% calcium chloride (by mass) will provide a -45°F (-42.78°C) freezing temperature of the brine. At this solution, the specific gravity is about 1.296.


Thanks mate

But why -42.78C i was assuming that i would be evaporating at -30C so the brine should be capable of around -32C:confused:
Thanks very much for your help, response

The MG Pony
27-05-2007, 09:33 PM
You want a safety margin for when weird things happen that we do not expect.

US Iceman
27-05-2007, 11:32 PM
The original evaporating temperature was stated to be -35C, and I always add some margin of safety to cover unexpected operating conditions.

I might be a little high on the concentration, but did so knowing very little about what you are trying to accomplish.

Insufficient information = increased safety factors.

chillyblue
28-05-2007, 09:53 AM
The original evaporating temperature was stated to be -35C, and I always add some margin of safety to cover unexpected operating conditions.

I might be a little high on the concentration, but did so knowing very little about what you are trying to accomplish.

Insufficient information = increased safety factors.

Ok

Thats great, thanks very much for your help

:) :) :) :)

Intermez
08-07-2007, 09:06 PM
Chilly,

Just as a matter of interest, tell me about your system. Size, application, refrigerant, etc.

Thanks, Intermez

chillyblue
09-07-2007, 06:14 PM
Hi Intermez

The system is used for making ice lolly's.
A brine soultion is in a tank and is circulated over a submersed evaporator within the same tank, the brine operates at -25deg. C, system evaporates at around -32deg. C.
The refrigerant used is R404A
The condensing unit is a Maneurope MTZ160 giving a duty at -30deg. C of around 8KW condensing @ 32deg.C
Expansion valve Danfoss TES5 with a Nunmber 2 orifice cage.
suction is 1"1/8 with a 1/2 liquid line

Hope this helps

Chilly Blue

suny
09-07-2007, 08:40 PM
Hey chillyblue

What is your problem? UsIceman has given the answer. The manufactured lollies are not hardened enough to remove from the moulds?

Suny

chillyblue
11-07-2007, 08:30 PM
Hey chillyblue

What is your problem? UsIceman has given the answer. The manufactured lollies are not hardened enough to remove from the moulds?

Suny

Hi Suny

As you said, i do not have a problem now, it has been resolved via this forum!!!, but if you look at the previous entry by Itermez i quote you will see i was just answering his question.

"Chilly,

Just as a matter of interest, tell me about your system. Size, application, refrigerant, etc.

Thanks, Intermez