Vacuum to recharge silica gel?

[Handeman]

Since a 2 stage vacuum pump is used to remove all moisture from your HVAC system before it is recharged, and it's what I use for vacuuming my propellant, can I throw my silica gel packs in my mixer bowl and pump the vacuum down to recharge them?

I know 250° F in an oven for a couple hours will do it, but the better half doesn't like that idea and I don't want to spend extra money on a toaster oven just for that since I have the vac pump already.

Anyone do this? Does it work?

TIA

 

[SolarYellow]

I've messed with vacuuming brake fluid, but not silica gel.

 

[Wrightme43]

you know I never thought about it, but it would lower the boiling point of water below room temperature.
I have a crazy vacuum pump for veneering wood, I don't see why it wouldn't work. Maybe I am missing something though.

 

[pugachu]

I make freeze dried food with a 2 stage vacuum pump (with a gast ballast). It will dry silica no problem. It can take time. Its best to have a micron gauge or torr gauge in line, so you can tell when its done. If you have one of those gauges, you pump down until it is well below the vapor pressure of water at room temp. Or just run it for a while.

I have a Welch duo-seal vac pump, and it can run 24/7 with no issues.

 

[tsmmiller]

I never thought or heard of recharging via vacuum. At the engine shop I worked at we recharged the silica cylinder plugs in our industrial oven.
Later in life the CAL CERT shop at my work site uses a microwave to recharge silica packs.

 

[prfesser]

Not sure it's worth the trouble. "Crystal cat litter" is silica gel with indicating crystals in it. Cheap enough to toss when the color changes.

 

[Donnager]

Yes, but why not just dry it in an oven?

220F will pretty much get rid of all the moisture. You will dry things a heck of a lot faster with applied heat rather than waiting for ambient temperature to make things evaporate, even at low pressure.

It's also pretty cheap, and maybe not worth the time.