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andre_fridge
06-03-2007, 01:25 PM
there are hard and fast rules to everything in life and I sit with the hard problems and the clients that want things done fast!
Does any body have experience with de-humidification with refrigeration units ?
what is the maximum moisture removal versus machine size, coil size, and temperature ?

My client wants to remove an estimated 6000 litres of water from 20 cubic meters of wood in 2 weeks flat.
not only is he driving me mad with his self imposed "time limit" but everybody else in the factory, so far with a TFH4531 compressor we have managed to remove an estimated 2400 litres in 10 days, is there any way we could speed up the process? with the excisting unit?

Cofreth
06-03-2007, 02:00 PM
Heat up the area to bring down the humidity?

NoNickName
06-03-2007, 02:10 PM
6000 liters in 24 days means 428 liters per day, or 17.8 liters per hour.
That's the dehum capacity of a medium sized AHU treating air *alone*, set aside wood.

I don't think it is possible with natural convection. I think the wood must be heavily warmed up, and even considering that, it may not be possible to convince wood to release that amount of water.

Electrocoolman
06-03-2007, 05:57 PM
I would have thought that its very much dependant upon the thickness of the pieces of wood, how they are stacked (open gaps) to allow airflow around the wood.
Temperature and humidity of the circulating air are also major factors.
I think that drying wood is a science in itself....if done too rapidly then it will crack and warp...the humidity of the chamber has to be carefully controlled and reduced gradually over time. Condenser heat can obviously be used to heat the chamber again provided it is controlled.

I think you will need to research this carefully.

The Viking
06-03-2007, 07:16 PM
The people to speak to is Munters,

As mentioned above, it's not just to remove the moisture.

As someone who grew up in the darkest woodlands of Sweden, I've seen quite a few "wood driers".
Normally they consist of a heater and a sorpsion dehumidifier, no fridge stuff at all.

Good luck,

andre_fridge
07-03-2007, 04:48 PM
OKAY
the riddle has been solved as with refrigeration there are rules that have to be followed and adhered to otherwise you will be burning your fingers
As I have done in the last two weeks!
the rules are as follows
1. thickness of the wood as in length versus breadth versus thickness
2. the amount of heat required to heat the wood to realease the water
3. the rejection of the excess heat created by the refrigeration process
4. creating and maintaining a stable evaperator pressure to facilitate maximum moisture removal
and bingo you follow the magic numbers (that took me 9hrs of googling to gleam from 7 different websites) to get to the fact that it is in fact possible to remove 6000 litres of water from a whole pile of timber, provided of course that you follow the rules!!!!!!
So after checking through all the data that I had accumulated I did the sums and my little 19000Btu compressor has pulled 2480 litres of water in 10 days which was well within spec of the figures
If any body has an interest or problem with the following they are more than welcome to contact me
YIPPPEEE
gonna go "bekruip" (leopard crawl) the bottle of red wine and celebrate!!!!

Josip
07-03-2007, 09:00 PM
Hi, Andre Fridge :)


OKAY
the riddle has been solved as with refrigeration there are rules that have to be followed and adhered to otherwise you will be burning your fingers
As I have done in the last two weeks!
the rules are as follows
1. thickness of the wood as in length versus breadth versus thickness
2. the amount of heat required to heat the wood to realease the water
3. the rejection of the excess heat created by the refrigeration process
4. creating and maintaining a stable evaperator pressure to facilitate maximum moisture removal
and bingo you follow the magic numbers (that took me 9hrs of googling to gleam from 7 different websites) to get to the fact that it is in fact possible to remove 6000 litres of water from a whole pile of timber, provided of course that you follow the rules!!!!!!
So after checking through all the data that I had accumulated I did the sums and my little 19000Btu compressor has pulled 2480 litres of water in 10 days which was well within spec of the figures
If any body has an interest or problem with the following they are more than welcome to contact me
YIPPPEEE
gonna go "bekruip" (leopard crawl) the bottle of red wine and celebrate!!!!

What about to share that with all of us;) in some general therms. Maybe some small example.

Best regards, Josip :)

andre_fridge
07-03-2007, 09:33 PM
the "bekruiping" of the red wine went absolutely wonderfully!!!!!!!!!!!!!!!
I will sit down and do a citation of the 'magic' numbers, but as of now my bed is calling as I have had far too much red wine, solved the worlds problems, and need some hard earned sleep!
expect something over the week end
till later

krazatchu
09-08-2007, 02:09 AM
Hi there....

I'm trying to put together a similiar system for a littel different purpose....

But I'm completely new to heat pump tech....

Could you possibly describe your system?

I see your using a pump thats rated for r22, what about the rest of the setup?

Valve type, condensor/evaporator specs etc...

Any help will be greatly appreciated.

Thanks,
Michael

TONY LONGTHORNE
09-08-2007, 02:44 AM
there are hard and fast rules to everything in life and I sit with the hard problems and the clients that want things done fast!
Does any body have experience with de-humidification with refrigeration units ?
what is the maximum moisture removal versus machine size, coil size, and temperature ?

My client wants to remove an estimated 6000 litres of water from 20 cubic meters of wood in 2 weeks flat.
not only is he driving me mad with his self imposed "time limit" but everybody else in the factory, so far with a TFH4531 compressor we have managed to remove an estimated 2400 litres in 10 days, is there any way we could speed up the process? with the excisting unit?

Hi Andre.
The moisture removel from timber is a trikey subject. If you remove the moisture too fast the timber will warp and twist which i am sure your client will not want, so impress upon him this fact. I do not have your conditions posted so i do not know how you are opperatining the system or your air circulation patten.
The basic rule is the drier and warmer the air passing over the timber the more moisture it will pick up and if your coil is sized correctley you will get your maximum drying capacity.
Are you passing the cooled air over the condensing unit to reheat it theres no moisture added by the hot air off the condenser. You should should aim for 30C minimum air onto the timber and the timber has to be stacked so as the air flows evenly over all sufaces or you will warp the timber. The slower you dry out timber the better the quality of the product.
Get on the web and down load vaisala humidity calculator it,s a great programe and will be most help full to you. good luck Tony L.
:cool:

Peter_1
09-08-2007, 04:03 AM
The people to speak to is Munters,
As mentioned above, it's not just to remove the moisture.

As someone who grew up in the darkest woodlands of Sweden, I've seen quite a few "wood driers".
Normally they consist of a heater and a sorpsion dehumidifier, no fridge stuff at all.

Good luck,
We've made in the past many wood dryers with refrigeration units.
How you think a Munters will react to the agrresive acid found in oak?
The weel will detoriate after a while.
But was the original question for wood. This wasn't mentioned in the first post.

Peter_1
09-08-2007, 04:05 AM
We made some units with ambients of more then 60C to dry oak (see other posts in this forum)