The purpose of this idea is, like that of the original Vacuum Reducer [link], to speed up the process of removing water from soups or sauces by reducing the air pressure above the liquid in question.

The bottommost part of the device is a flat disk of metal with a large hole in the middle, and a rubber or silicon layer on it's underside; the outside diameter of the disk is large enough to cover the lip of the largest common size of pot or pan, the diameter of the hole is small enough to allow the disk to rest on even small saucepans.

Attached to the top of the disk is a pyrex glass dome, whose shape is a portion of a sphere (for greatest strength against atmospheric pressure). At the top of the dome is a handle, and a place to attach a (removable) vacuum tube (both of these are molded into the glass).

The vacuum tube is a few feet long, enough to reach the typical distance from a stove to sink.

At the end of the vacuum tube is a heat exchanger (cooled by ice water) and an electrically powered vacuum pump (able to remove both air and water from the vacuum).

It works using much the same as the original vacuum reducer: speficially, it reduces the boiling point of the sauce, allowing it to boil at a lower temperature. Since the sauce is at a lower temperature, so is the pan. Since the pan is at a lower temperature, it absorbs the heat from the fire more efficiently.

However, it has some big advantages:

1) The part sitting on top of the pot is lighter and less cumbersome

2) It has a see through lid (allowing you to know when enough water has been removed).

3) Since the air being pumped out is cooled by the icewater, it's denser, requiring less work on the part of the pump.

Once the water starts boiling, the air will largely be replaced by water vapor. Once this happens, the vacuum pump will be pumping water out, which is much denser, and therefore requires less energy to remove.

By making the tube long enough to put the pump in the sink, we also provide an easy way to dispose of condensate. (Of course, if you're reducing a wine based sauce, you might not want to "dispose" of the condensate this way ;)).

The only minus of this device is that it's an electrical appliance sitting in the sink... this is not a big deal, provided that it's appropriately insulated.
-- goldbb, Mar 03 2009

The Original Idea Vacuum_20Reducer
[goldbb, Mar 03 2009]

umm... can I borrow your condenser ? you don't actually need it...thanks
-- FlyingToaster, Mar 03 2009


Look, have you ever cooked at high altitude? Nothing cooks right because the boiling points are all too low. If you are making a sauce, rue, or reduction the heat is essential to producing the richness and complexity of flavor. Boil off the water and nothing gets hot and the flavor is not there. You have a solution looking for a problem. I'm not saying there is no application, just that you haven't found one yet.
-- WcW, Mar 04 2009


I thought that the goal was simply to remove the water as quickly as possible... as FlyingToaster said in his original idea,

/Mind, this is *not* a method of cooking, and it certainly isn't a way of making a good cup of tea; simply a better way to reduce stocks and sauces./

His idea got 27 votes in favor of it... so it must have something going for it.

The only real changes I've made are adding an icewater cooled condensor, making the lid mostly clear, and adding a tube from the lid to the the condensor and vacuum pump, so they can sit in the sink.

My version doesn't really do anything *different*...

It's just easier to clean (the parts seperate from each other), easier to see how much water's been removed (the glass top), it puts a lighter load on the motor running the vacuum pump (the condensor), and it's is less likely to cause a mess (since most of the device sits in the sink).
-- goldbb, Mar 08 2009


Here's an application: How about a vapor distillation machine that uses a vacuum? Vapor distillation machines (for water purification) use up a lot of energy boiling off water, because water has such a high specific heat. If you reduced the air pressure, boiling the water off would be faster and use less energy.
-- plasticspoon, Mar 08 2009


// His idea got 27 votes in favor of it... so it must have something going for it. //

Probably that most people don't know didly squat about cooking.
-- jhomrighaus, Mar 08 2009


sp. "diddly squat"
-- FlyingToaster, Mar 08 2009


Rather than using using an electric pump in the sink, could you use a device similar to the ones we used in Chemistry lessons, where a T-piece could draw fluid out of a reaction vessel, powered by flowing water through it (tap in sink).

The device worked by having a main fluid flowing through venturi style orifice (therefore at high speed and low pressure) with a feed from the desired vacuum on the side of it.

Whether the sauce is as good as the old fashioned way, we can leave up to the diners!
-- Skrewloose, Mar 08 2009


took me a few days to get my nose out of joint long enough to realize why you want a condenser on it, makes some sense but I think ice-water is a bit much: if you're not concerned about trying to keep a *total*ish vacuum you can make do with a small electric fan. I'm gonna stick with my original plan though: energy usage is a drop in the bucket compared to the KW'age of the burner.

ummm... pyrex is neat and water won't condense on the glass given the lower air-pressure inside, but that sortof keeps you from using the "all size" feature... and you still have to take the lid off to taste and stir occasionally anyways.
-- FlyingToaster, Mar 09 2009


Oh, I'm not expecting a total vacuum, or anything anywhere near it. I'm just hoping to get the air pressure down to what you'd get at the top of a very tall mountain (which I don't think you could accomplish with a fan).

The condensor isn't just to save energy, it's to save time. Assume that you and I use identical piston based vacuum pumps, spinning at the same speed, and that all the air's already been removed and replaced with steam; then each rotation of the pump in both of our designs removes the same volume of fluid. But since the fluid in my design will be liquid water, and in yours it will be gaseous steam, my pump removes a larger mass of H2O than yours... so mine, due to the condensor, works faster.

About the pyrex dome... notice that it's attached to a flat metal disk (just like the disk in your original design), with a central hole for that dome.

So although the device is not completely universal, it will work on any pot whose diameter is larger than that of the pyrex dome, and smaller than that of the flat metal disk.

For pots smaller than the dome, one could swap out the disk/dome component for a smaller one, since the vacuum tube is removable.
-- goldbb, Mar 11 2009


ahh k, I pictured your dome as being large and the lid going underneath it... you still won't be able to taste the sauce through it though :D

Still think mine would have a firmer infomercialbility seeing as it's a potlid which plugs into a stovetop socket whereas you have Frankenstein's laboratory there.

[edit] you could get away with a handcrank.
-- FlyingToaster, Mar 12 2009


Since the steam is being condensed before being removed, that might just be possible :)

For that matter, a pushbutton pump might work... a piston pump is pulled "closed" (towards decreasing volume) by a spring, and "open" by the user pushing down on a button.

Either way, the pump and perhaps condensor would need to be made of transparent materials, to allow the user to see that there's water that needs to be removed.
-- goldbb, Mar 19 2009


//transparent material//
not really, you could have a pre-pump cylinder that when it weighs so much pushes the button which activates the pump which releases the water which lets off the button which deactivates the pump.
-- FlyingToaster, Mar 20 2009



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