Vacuum pump to dry inside of tank? Refrigeration people?

[AngryJonE5]

So I was explaining to my father the process I'm familiar with for cleaning the inside of tanks: Simple green wash, water rinse, alcohol rinse, then blow dry air to evaporate the alcohol. He asked why you couldn't use a vacuum pump like refrigeration people use to remove moisture from their systems.

He stumped me on this and after a little internet research I still don't see why it couldn't work to run the vacuum hose to the burst disc port on a tank valve then hook to a fill whip to fill back to ambient pressure with dry air.

Any people with vacuum pump, refrigeration, HVAC experience who could chime in here?

Thanks,
JonL

 

[pickens_46929]

Ummm... because really dry compressed air is readily available?

 

[Randy43068]

A) the tank would collapse killing everyone in the neighborhood.

I go with what Pickens said. It's easier to blow than to suck... so I hear.

 

[Web Monkey]

So I was explaining to my father the process I'm familiar with for cleaning the inside of tanks: Simple green wash, water rinse, alcohol rinse, then blow dry air to evaporate the alcohol. He asked why you couldn't use a vacuum pump like refrigeration people use to remove moisture from their systems.

He stumped me on this and after a little internet research I still don't see why it couldn't work to run the vacuum hose to the burst disc port on a tank valve then hook to a fill whip to fill back to ambient pressure with dry air.

Any people with vacuum pump, refrigeration, HVAC experience who could chime in here?

Removing water with a vacuum pump is like drying your car with q-tip.

It will eventually work, but takes a really long time (could be days).

Terry

 

[vam302]

I use mechanical vacuum systems at work, so here's my .02... While it may remove moisture out of the tank, that moisture is going to go somewhere. That somewhere is going to be the vacuum oil. A common way to alleviate this is to include a cold trap (condenser) in the line. Also, you would need to figure out just how much vacuum you want to achieve, and how fast. A typical mechanical vacuum pump that pulls around 10 cfm will run you upwards of 1k.

10.6 cfm Mechanical Pump

So, like the others said, it's probably more economical to blow than suck, er...yea.

BTW, I don't know anything about refrigeration or HVAC, so maybe someone else could give their side of the story.

 

[captain]

Dry in 60 seconds. Use hot, really hot water for final rinse. Connect an old LP hose with the 2nd stage connector cut off to your first stage mounted on a tank. Insert LP hose into tank full of hot water, invert tank, open air. Air will force hot water out and dry tank in about 60 seconds.

 

[dannobee]

Yes, a refrigeration vacuum pump would work.

The reason HVAC uses vacuum to remove moisture isn't what most people think. The high vacuum boils the water in the system, then the water vapor gets removed.

Not all of the vacuum pumps used for HVAC are electric. Some use a venturi, much like a carburetor and are hooked up to your shop compressor.

 

[pickens_46929]

Dry in 60 seconds. Use hot, really hot water for final rinse. Connect an old LP hose with the 2nd stage connector cut off to your first stage mounted on a tank. Insert LP hose into tank full of hot water, invert tank, open air. Air will force hot water out and dry tank in about 60 seconds.

Man that's like Grandma used to say about washing dishes... Hot water dries quicker

 

[landonnin1]

Water and any other liquid boils when its vapor pressure reaches the pressure above it. Once the liquid reaches a temperature where it does, all the heat going into the liquid is absorbed by vaporization and the temperature can't rise.

Several things affect the boiling point. Atmospheric pressure varies, changing the boiling point. Water can be made to boil at room temperature with a vacuum pump.
Inches of Mercury

Vacuum pump would work but the vacuum just lower the point where the water will boil
inches of mercury / boiling point of water
@ 26.45 /120 F
27.32 / 110 F
27.99 / 100 F
28.50 / 90 F
28.89 / 80 F
29.18 / 70 F
29.40 / 60 F
29.66 / 50 F
29.71 / 40 F
29.76 / 30 F
29.82 / 20 F
29.86 / 10 F
There are some numbers for you hope this helps but as stated before it could take a while to get higher vacuum. This is why when we change out an Ac unit we like it to be a warmer day. We use electric vacuum pumps

 

[SDAnderson]

So I was explaining to my father the process I'm familiar with for cleaning the inside of tanks: Simple green wash, water rinse, alcohol rinse, then blow dry air to evaporate the alcohol. He asked why you couldn't use a vacuum pump like refrigeration people use to remove moisture from their systems.

He stumped me on this and after a little internet research I still don't see why it couldn't work to run the vacuum hose to the burst disc port on a tank valve then hook to a fill whip to fill back to ambient pressure with dry air.

Any people with vacuum pump, refrigeration, HVAC experience who could chime in here?

Thanks,
JonL

Alcohol? Vacuum pump? Planning another Saturday night alone at home cleaning your pipes, er, tanks...right?