Eco-friendly wood dryer humidifier

[dedeleco]

Funny, both are right, if we do not forget the formation of vapor cloud:

I saw a vacuum dryer work: you can immerse the vacuum pump outlet pipe in water it condenses at 100%, and this pipe is well above 100 °
more exactly I do not immerse the entire pipe, because it is 120mm in diameter and it exits a jet of steam of hell, I am satisfied to derive part of the flow in a small silicone pipes

and the hell pump (root?) which pumps a jet of hell is at that temperature continuously? Over 100 ° C !! And the noise of hell too !!!
And what dries in the dryer becomes a block of ice unless you heat what dries very strongly, hell ????
Because the steam water is at the pressure corresponding to its temperature
http://fr.wikipedia.org/wiki/Pression_d ... _saturante
more the compression of the vapor heats it strongly.
, but on a simple pump no hell, it will come out at the pressure corresponding to its temperature (fixed by P, T, starting and compression) and the rest in a cloud of droplets of condensation mixed with its vapor and therefore the pump will fill with liquid water at the same time as the steam comes out in a cloud full of water droplets !!! On a vane pump, the oil fills with water and the pump dies quickly !!!
On a centrifugal compression pump, the vapor can exit below 100 ° C with a cloud of predominant water droplets, with especially the air for entraining water vapor on an intermediate stage of the pump.
But in the industry for drying high-value products, we do not look too much at yield, but at speed! Drying of what ?? Maybe we were happy to precook it at the same time?

Finally, in atmospheric clouds, there is often a delay in condensation due to the lack of nucleation nuclei of condensation (dust or cosmic rays), and in pumping, condensation can have a delay in a flow of hell! !

This delay is very important because it changes the cloud cover and the climate, according to the cosmic rays which are modulated by the activity of the sun in the climate, much more than CO2 !!
Earth is Wilson's room !!
http://fr.wikipedia.org/wiki/Chambre_%C3%A0_brouillard
http://fr.wikipedia.org/wiki/Charles_Th ... ees_Wilson
http://www.masc.ulg.ac.be/fiches/FR/chambrewilson.pdf
http://www.meteolafleche.com/Soleil/ray ... limat.html

Finally, we can dry and pump with a water pump without going up to 100 ° C, with a booster pump for water in closed circuit !!
http://fr.wikipedia.org/wiki/Trompe_%C3%A0_eau
But the solar dryer is almost free !!

[chatelot16]

it was a liquid ring pump, full of oil

there was no condensation in the oil because it always worked at more than 100 °

there may have been some condensation in the oil when cold started, but it did not last

this same type of liqueide ring pump is also used in tiles with water instead of oil, but the goal is not the same, less strong depression ...

to suck the water vapor a liquid water ring pump would not work, the water would evaporate too!

of course letting the vacuum pump compress the steam to 100 ° is energetically stupid: cooling this steam during compression to stay at a reasonable temperature would have saved energy: but in the industrial equipment of the time the economy of is not the priority

worse to activate the drying of the wood there was an oil boiler to heat the wood before putting it under vacuum: person would not have thought of using the heat of the compression of vapor to make this heating whereas the power wasted was largely sufficient

[bernardd]

Obviously, you each had a negative experience with materials not suitable for water vapor ...

But the proof of the impossibility cannot be reduced to counterexamples.

Personally, I was going on a diaphragm pump which supports steam and liquid water. This is the good old principle of the bellows, economical, simple and without special maintenance. But I have not yet been able to test in this context.

As for the rise to 100 ° at the outlet, I do not understand why it is necessary to compress the outgoing air: in principle, I have a room which contains water vapor at a few mbar, I open it in the atmosphere, then I decrease its volume to expel this air. I did not spend energy to compress, the atmosphere does it ...

In addition, I fully know the interest of vacuum solar collectors to have hot water storage for operation outside the sun, but despite this the energy required remains high and the time long. "Adding vacuum" is the only way to go faster while spending less energy.

[dedeleco]

Comments on your proposal:

As for the rise to 100 ° at the outlet, I do not understand why it is necessary to compress the outgoing air: in principle, I have a room which contains water vapor at a few mbar, I open it in the atmosphere, then I decrease its volume to expel this air. I did not spend energy to compress, the atmosphere does it ...

water at a few mbar below 20 ° C = 23mbars and 0 ° C = 6mbars, ie low pressure, almost empty and when the air is opened at 1 bar precipitates into it violently (Joule relaxation) and gets cold, therefore condensation of the vapor, then replaces and mixes with the water vapor with the hot air at 1bar at the end, but there is no compression of the vapor, only dissolution, in the air !!
The usual vacuum pumps do not work according to this principle because when we vacuum in a container where there is wood to dry (or a source of water that evaporates) by making the vacuum we suck the air and the water vapor which arrives with it, and very quickly we end up pumping on the low pressure water vapor.
Let's say a few mbar, and the usual pump must take out this vapor at 1bar.
So you propose to mix this low pressure steam with a lot of air, just after the end of the suction at the start of the compression which is replaced by an air intake followed by an expulsion of the air with the little water vapour.
On rotary vane pumps, air can be introduced as the entraining gas to extract large degassing rates, which somewhat corresponds to this possibility.
Diaphragm pumps do not usually do this because they want to recover the pumped gas, instead of losing it by polluting the air.
But nothing prevents changing a diaphragm pump by opening the outlet valve or valve very early, as soon as compression begins.
I do not know if commercial diaphragm pumps have provided for this possibility of outside air entering at the start of expulsion, instead of compressing the pumped gas.
We must be able to tinker with a diaphragm pump for this and greatly reduce the energy expenditure of compression.
For wood to dry, you need a fairly large resistant vacuum container of a fairly high price, especially with a large opening, to enter the wood, about 1m3 !!
I think its price is very dissuasive, compared to that of a 1m3 plastic rainwater collector !!
But we can do it log by log, spending an hour each, in a small container !!!
Personally I am more motivated for drying in the sun (in summer) and to keep with care so as not to regain the humidity of the air at night and in winter (rarely done with care to store logs, difference with granules) .
examples of pumps you need 2 stages (less than 80mbars) and you compress at the outlet
http://www.directindustry.fr/prod/vacuu ... 35496.html
pump head drying pump:
http://fr.vwr.com/app/Header?tmpl=/new_ ... prod10.htm
But nothing on the possibility of entrainment air intake before compression ????
example of a vane pump with an air drive "gas ballast valve":
http://www.directindustry.fr/prod/oerli ... 31258.html

[bernardd]

For the direct use of the sun or cold air for logs, I agree. But I am interested in the use of green waste from a house.

I was looking at this kind of pump:
http://www.knf.fr/dn_integrables/?start=40

For the absence of compression, this is not the first time that I would come across a simple thing which "does not exist" ;-) For the moment I am going around the principles and the experiments.

For the enclosure, we can think of many solutions, the fridge, more airtight than we think thanks to the magnetic seal, to used stainless steel enclosures, or even downright good concrete stuff ...

PS: I really appreciate your help, especially since this subject went against your initial convictions.

[dedeleco]

I looked at the GI280 characteristics for 2mbars and 60l / min and 1bar (end of the list) which evacuates 20litres in 2min, but nothing is planned not to compress the outgoing gas !!
The pump should be redesigned at the valve or control cam level.
Another solution is to shake the divided plants, in very dry air, after passing over a cold condenser (old fridge block), which will give the same rate of evaporation, almost, requiring less energy.
My green kitchen scraps make soil all by themselves in the garden, but they don't make energy.

Otherwise when I reread it, I realized that my reading too fast gave me false convictions, out of habit, while lots of different solutions are possible!

[bernardd]

The pump should be redesigned at the valve or control cam level.

certainly, but i'm in principle.

very dry air, after passing through a cold condenser (old fridge block), which will give the same rate of evaporation, almost, requiring less energy.

I still cannot be certain about the comparison of the necessary energies. Draining the air followed by a cold condensation cycle would be even more effective anyway.

out of habit, when lots of different solutions are possible!

I know, forget his habits: the hardest ...

[chatelot16]

pumping vacuum is anyway compressing

how else to explain going from almost 0bar to 1bar?

dilute with air? what a horror it will require even more power

only solution to condense the vapor before pumping the vacuum: if all the vapor is condensed in water the volume to be pumped (therefore compress) will become very small

problem the condenser will receive all the heat of vaporization therefore of condensation of the water to dry: and the refrigerating machine will consume energy to raise this heat from the very low temperature of condensation to room temperature: which will be saved for the vacuum pump will be consumed worse by the refrigeration machine

other solution absorb the water vapor with calcium chloride before the vacuum pump: it will absorb all the vapor and greatly reduce the volume to be pumped

but calcium chloride is not free: its energy production cost is greater than the saving on the power of the vacuum pump

but it's not that stupid: the calcium chloride and water solution can be dehydrated by heating it (in the sun when there is one)

wet biomass waste cannot be stored while waiting for the sun: it can: dry immediately using calcium chloride is very good: the dissolved chloride can wait without loss on the day when there is sun to dry it

but finally it is very complicated: this is why my favorite solution for wet waste is methanization: no need to dry: we let bacteria in the water

[bernardd]

pumping vacuum is anyway compressing

No, it's just moving. By the way, we just have to go down to 1 and 10mbar, it's pretty rough vacuum.

only solution to condense the vapor before pumping the vacuum: if all the vapor is condensed in water the volume to be pumped (therefore compress) will become very small

This is the idea.

problem the condenser will receive all the heat of vaporization therefore of condensation of the water to be dried: and the refrigerating machine will consume energy to raise this heat from the very low temperature of condensation to ambient temperature:

Around 10mbar, it still condenses around 0 ° C, so standard refrigeration equipment would suffice. But it should especially be tested, because I can't find a lot of technical documentation on these subjects.

other solution absorb the water vapor with calcium chloride before the vacuum pump: it will absorb all the vapor and greatly reduce the volume to be pumped

Yes, still a possibility, but as you say it must also be recycled, it becomes complex.

but finally it is very complicated: this is why my favorite solution for wet waste is methanization: no need to dry: we let bacteria in the water

We have already talked about it, I think that the granulated solution will be simpler and more effective ... but only when it is ready ;-)

[dedeleco]

Fun, like me, out of habit, nobody thinks about it !!
I had written at length to explain what had escaped me, but it was not enough;

pumping vacuum is anyway compressing

how else to explain going from almost 0bar to 1bar?

dilute with air? what a horror it will require even more power

In the complete vacuum there is nothing and therefore nothing to compress at all !!!
The incomplete vacuum where molecules remain, for example 10mbar of water vapor, can be pumped by compressing these molecules by taking them out at 1bar to lose nothing of the water. But this water vapor at 1bar must be at 100 ° C if it remains in the vapor state, otherwise if it remains at low temperature at 20 ° C by pumping the small steam part will stay at 23mbar and the rest will be liquid, spontaneously compressed in liquid water !!
The pump, diaphragm or the like will release a mixture of liquid and a little steam.
If the liquid does not spontaneously come out of the wrongly oriented pump by flowing down, the pump will fill with water, will start to compress the liquid water, not very compressible and therefore knock hard and destroy itself !!!
On the vane pump, the air drive "gas ballast valve" allows air to enter to release the water in the form of a cloud in this air !!
On the diaphragm pump nothing similar seems to be expected.
It is necessary that on the modified pump, after the first phase where the membrane sucks the 10mbar of water vapor in the suction chamber, just after its disconnection from the almost empty container, instead of unnecessarily compressing this vapor, which refuses to exceed 23mbars, we open the air to 1Bar to mix it with this air which precipitates violently and which is evacuated after 1bar, with a partial steam pressure of 23mbar at 20 ° C, without the slightest work of compression.
I hope I have been clear in detailing each step of the pump ???

Otherwise, having recycled calcium chloride after absorption of water, it can be dried by heating (sun, stove, stove), but it must be shaken vigorously to break the dry and hard crust like a pebble, which forms on the surface, otherwise the very hard dry surface prevents drying of the liquid hidden underneath for days and days !!!