planning/setting evap temp with cap tubes

[kubae]

Hi Everyone,

I am planning on acquiring a compressor and suitable condenser and self-build an evaporator to be contained in a self built chest freezer. The purpose is to freeze water in cellophane packs. I'd like to freeze between 250 and 500 liters of water (in 5 liter packs) at a time and I'd like this as fast as possible i.e 60 minutes to 180 minutes. My question is would a 7.5 hp do the job in 180 minutes or less and what would be the impact of going to a 15hp compressor? how do I set evap temp to lowest possible? I will be using either of R502 or 404A. Thats whats available. I might get some knocks for this but I have experience only with cap tubing and intend to use them. I plan multiple evaporators and have a bit of experience using these with cap tubing. I have absolutely zero experience with other metering devices and the cost here is prohibitive too.

What I really need is confirmation that its possible (with which compressor power [hp]) and an understanding of how to set evaporating temp as low as possible to speed up the process. I have been able to use smaller 1 phase compressors to good effect but haven't gotten near the speed I'd like.

[taz24]

Hi Everyone,
I'd like to freeze between 250 and 500 liters of water (in 5 liter packs) at a time and I'd like this as fast as possible i.e 60 minutes to 180 minutes. .

You want to freeze upto 500kg of water in 2 to 3 hours using a system with capilary tubes.

You do not tell us the start temp of the water or the end temp!

:D Good luck you will need it.

taz.

[kubae]

Right now, I have machines I self built which I use 2 2HP hermetic compressors for and which freeze 264 liters of water in 9 hours flat. Ambient is average 34C (94F) with water starting at 27C (80F) and cabinet temp going down to -22C (-8F). I have found that left for about an hour more, cabinet temp goes as low as -27C. Thats cabinet temp, not ice temp which I've never measured. That they are brickhard is sufficient.

Coming from a non technical background (but having the time of my life doing this), my reading up suggests that with even lower evaporating temps, I can speed up the process. Thus the desire for a bigger compressor and thus more duty capability. Cap tubes are affordable and easy to apply. Thats thier appeal.