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Lc_shi
21-02-2005, 04:57 AM
who have used liquid desiccant dehumidifier ?

Peter_1
21-02-2005, 08:28 AM
First time I hear of this?
Can you explain perhaps a little more Lc?

Argus
21-02-2005, 12:49 PM
Liquid dessicant is a new one on me, too.

Normal dessicant dehumidifiers are basically a miniature heat wheel heat exchanger impregnated with a silica gel or similar dessicant agent.

The wheel turns slowly in a dual chamber. Cool moist air is introduced to one side - a heater re-generates the wet dessicant on the other side - the hot moist air is rejected.

Even quite small ones are capable of rapid moisture removal.

In my experience the portable ones are used for moisture removal in buildings, after floods etc. Bigger ones are used in process control, but that's a bit specialised.
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chemi-cool
21-02-2005, 04:13 PM
Hi guys.

Liquid dessicant is used for drying large green houses.
There is a company in Israel that specialised in it.

It is also used for hot Spa's for drying and cooling.

The stuff they use is bad for your skin and attacks metal very quick, no matter if it is galvanised or epoxy painted.

Chemi :)

Argus
21-02-2005, 04:35 PM
Sounds like Lithium Bromide.......
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chemi-cool
21-02-2005, 06:53 PM
Yas Argus, thats the stuff.
Horrible, isn't it? :eek:

Chemi :)

Argus
21-02-2005, 10:08 PM
Never used outside big Abos myself, the stuff would shrink your boots.

What do they do with it? wash the tomatoes?
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Lc_shi
22-02-2005, 02:03 AM
It's used for supplying dry air for DOAS. It's said it can incorporate with low-level heat resource.

for your ref
http://www.nrel.gov/desiccantcool/intro.html

Argus
22-02-2005, 05:17 PM
It's used for supplying dry air for DOAS. It's said it can incorporate with low-level heat resource.

for your ref
http://www.nrel.gov/desiccantcool/intro.html

What are DOAS?
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chemi-cool
22-02-2005, 08:11 PM
Dedicated Outdoor Air Systems


Chemi :)

coolman
22-02-2005, 11:21 PM
who have used liquid desiccant dehumidifier ?

I amongst other types op dryers used liquid dessicant dehumidfiers.

If you plan to use it for large greenhouses or anywhere where the average temperature is mostly above 7C I would advise you to switch to fridge dryers cause under these circumstances theze would have a mutch better water extraction and lower power consumtion.
There is also a possibility to remove heat and or reclame heat.

Regards Victor

Lc_shi
23-02-2005, 01:39 AM
Chemi
Any more information about your said Isreal manufacture?

satoof
03-11-2007, 11:31 AM
easily desiccant is used to treat the latent part, rather than sub-cooling or other methods used in TVCACS, which followed mostly by reheating. i.e. inefficient thermodynamically.

Peter_1
03-11-2007, 11:59 AM
Correct me if I'm wrong but if you have to remove a certain amount of water, you need energy to do this.
If you use a desiccant dryer or a cooling coil with reheat (reheating with a condensor is better of course), the total energy to do this will be +/- the same, apart for the efficiency of course of the used drying system.

Ravi
05-11-2007, 07:05 AM
The total energy remains same in any process. The advantage with desiccant dehumidifiers is that, the secondary refrigerant (water/brine) temperature need not be as low as if you are using cooling/heating method. So, you can run your refrigeration system for a bit higher temperature. However, whether we can save energy or not is highly doubtful as the desiccant is to be regenerated using electricity (generally) which is a high grade energy.

I have used LiCl based liquid desiccant dryers and then replaced them later along with the duct work.

S.M.Gokhale
05-11-2007, 09:44 AM
Hi Lc,
I think the type of dehumidifier you are refering to is perhaps manufactured by 'Munters'. You can google Munters for more info.

It incorporates Lithium Chloride as a liquid desiccant. It is felt by some engineers that flakes of dry desiccant (like silica gel) can get entrained into air stream where it would be easier to contain leakage of a liquid desiccant.

S M Gokhale

Ravi
05-11-2007, 11:34 AM
Ease of containing liquid desiccant over solid desiccant is an understatement. The only advantage of liquid desiccant dehumidifier is that we need not have a cooling coil after the dehumidifier. Sensible cooling can be acheived by varying desiccant flowrate (the process is not necessarily isenthalpic and the process line can have any slope on the psychrometric chart).

Munters are mainly into desiccant dehumidifiers. Kathabar and Drykor are liquid desiccant dehumidifier manufacturers and I used both of their equipment.

The MG Pony
06-11-2007, 04:27 PM
Holy necrothread batman!

satoof
06-11-2007, 08:34 PM
actually u r correct, but the point is the average reactivation energy of the desiccant is low, especially for Liquid desiccants, i.e. low grade energy source ( solar, co-generation plants, hybrid with conventional Vapor Compression systems........) will be enough, add to that, by using solar energy and using direct and or indirect evaporative cooling to handle the sensible load part, it will be totally environmentally friendly, minimizing the electricity needed ( just small part to run the pumps and fans) no CFC's.............
it will be a revolution in cooling and air conditioning
just a matter of time

satoof
12-12-2007, 12:11 PM
hey all;
i have one, but now i am trying to find such a wick material with good characteristics, instead of cotton, may anyone support me.
cheers