DIYbanter - View Single Post - Vacuum pump from refrigeration compressor questions

mike[_22_]

On 5/4/2017 9:39 AM, wrote:
On Thu, 04 May 2017 12:16:27 -0400, wrote:

On Thu, 04 May 2017 08:48:11 -0700, wrote:

All over YouTube are examples of folks using either air conditioner
compressors or refrigerator compressors for vacuum pumps. I know I can
buy a Chinese 3 cfm two stage pump good for 25 microns or so for about
$160.00. I have seen these reviewed and they are pretty noisy. The air
conditioner and refrigerator compressors are much quieter. I'm not
looking for a vacuum source for vacuum chucking, but am instead
thinking of using one for vacuum infusing stuff. Like food. And also
of vacuum storage of dried foods. To do this I would stack cans in my
big pressure canner with the lids in place. Using a plastic lid I
could watch the process. I already have the plexiglass material for
the lid that's plenty stout enough for the job. If the can lids won't
retain their seal when I run them through the can sealing machine I'll
just resort back to glass. So what are the disadvantages of using a
repurposed refrigeration compressor besides getting my hands on a good
one without having to let all the refrigerant out into the atmosphere,
which I am not willing to do.
Thanks,
Eric
How are you going to address the lubrication of the compressor? In a
refrigeration system the lubricant circulates with the refrigerant to
circulate through the cyls. When used as a vacuum pump this does not
happen.

Will it work?
Sure - for a while. How long? Who knows - but the pump will
deteriorate with use.
Actually, from what I have seen on YouTube, the compressor gets
adequate lube, especially the refer types which actually have the
motor submerged in oil.

Won't you be sucking a lot of moisture? That can't be good.
I'd at least think about the possibility of getting vapors
from the compressor back into your food.

Educate me on the value of high vacuum food preservation.

For bag sealing like seal-a-meal, the purpose of the vacuum is to
EXCLUDE air by forcing the plastic into contact with solid chunks
of food, like chicken breast.
Once contact has been achieved, higher vacuum has no purpose.
I suggest it's a detriment.
The higher the vacuum, the more likely you'll hasten the exit
of water from the food into any voids that exist.

I bought a bunch of rigid plastic containers with vacuum inputs
at a garage sale and tried to learn how to use them.

I concluded that:
If you can't force the container into contact with the food,
the best you can do is to exclude air with vacuum.
The seal-a-meal vacuum pump I have couldn't do much better
than removing 2/3 of the air.
If Oxygen is what causes food to go bad, higher vacuum removes
more of it.
If you use higher vacuum, you suck moisture out of the food.
If that results in a puddle somewhere, that can't be good.
I assume you wouldn't want to wait long enough for all the
moisture to be removed by the pump.
Higher vacuum probably results in more air and/or pathogens
being sucked in over time thru tiny leaks.

A nitrogen purge might be better than trying to extract the
oxygen directly with a vacuum pump.

Bottom line is that my rigid vacuum sealed containers are
sitting quietly in the attic awaiting my next garage sale.