Water brine solution for freezing purpuses

[Salah 1]

Dear members:
I have an idea of using water brine solution for freezing plastic water bottles,how practical such design?
I think about using same idea of vapor compression refrigration unit but the evaporator (will not be an insulated room with crazy fans running inside, with the importance of insulation and long time to get the job done) ..
instead it will be insulated water brine solution basin with evaporator coils running inside in the upper side :
The coold energy can be stored for long time .
Water specific heat is much higher than air ,which means that even with some air leaking into the basin it would not effect the process as in the case in walk-in freezer.
Thermal conductivity of water is much better than air which might make shorter time to get job done. ..
I know that some corrosion issues might make this unpractical...
But anyway, how such design is practical?
Thank you.

 

[LittleInch]

Freezing plastic bottles full of what? Water?

Why??

Just stick them in a freezer.

I can't follow what your trying to do and why this would be a good idea.

 

[Salah 1]

Thank you for your reply, I am trying to do same thing as ice block machine which as I guess works well using water brine solution.....
I was looking for something more releated to heat transfer, thermodynamics basics.
Thank you anyway..

 

[EdStainless]

In the food processing industry, they often chill product using water.
As long as you pump pure water vigorously it will stay as slush a few degrees below freezing.
They us this bath to get products nearly frozen quickly and then they put them into freezers to let them finish freezing.

 

[LittleInch]

Thank you for your reply, I am trying to do same thing as ice block machine which as I guess works well using water brine solution.....
I was looking for something more releated to heat transfer, thermodynamics basics.
Thank you anyway..

Well give us some data to work with then.

This https://www.engineeringtoolbox.com/sodium-chloride-water-d_1187.html gives you an idea of the freezing point of brine. You probably don't want to be within 5C of this.

Seawater is 3.5%. So to get anything decent you're looking at 15% by mass. If that gets aerated and warm that's a very corrosive fluid so you need high cost materials to avoid corrosion.

At the end of the day is all about heat transfer and heat transfer rate.

Very cold blown air can chill things very fast. So yes the heat transfer is better with water and the is a larger heat capacity of water but if you're cooling water then some of that advantage goes away.

You asked a very vague question which tends to get very vague answers.

 

[Salah 1]

Thank you for the reply :
As I understand the water brine solution in the case of an ice block machine should be made with 23% NaCl by mass or volume?
The brine temp should go down to minus 10-15 celsius...
that is why I asked if such system can be used for freezing purposes instead of using walk- in freezer..
To give you more info I could (during the day)get water temp drop of 12 using evaporative cooling with water final temp of 12 celsius simply by putting a water bowl in the surface with wind air passing through...
And during the night I could start at 8 pm with that water bowl at 12 celsius and make it even colder using night sky radiative cooling with final water temp about +3 celsius in the morning at 5:30 am..
Now with such water I could safe some time and energy to run either water brine brine freezer or normal vapour comp freezer by precooling the material required to be freezen befor ...
the limiting stage might be the one with phase chane which consumes most of the energy but anyway ....

 

[georgeverghese]

So you want to freeze water in PET bottles ?
If this water is meant for human consumption, you could use food grade PPEG-water solution also as the chilling medium. And chill the PPEG in a countercurrent PHE with anhydrous ammonia or CO2 compression cycle