Tube in tube air dryer 1

[pardal]

At a plant, I have compressed air at 7 to 8 bar relative flowing in a 2" cooper tube.
The normal air is token from ambient , ranging from 5°C 30% Relative Humidity [RH] in winter to about 35° 95% in summer after a rain.

The flow is 450 liter/m normal air .

I have allowable all year round, water at 7°C .

My intention is to make a air dryer by a tube in tube heatexchanger. Inner tube for air outer for water , properly isolated.

The dew point to mach should be 2 to 5 °C but some deviation is aceptable.

I will be grateful if you can give any advice on it.

Regards










Pardal

 

[hacksaw]

That is generally referred to as a cooler, not a dryer. Is it adequate? Only you can answer that.

 

[pardal]

by cooling it will dry .


Pardal

 

[pennpoint]

How do you plan to rid yourself of the condensate? After cooling the compressed air what happens to the process water?

pennpoint

 

[pardal]

Of course I will drain it by an water trap.
What do you mean by process water, the condesate??
or the warm water??

If condensate , as up explained .

If warm , to the chiller return circuit.

Other question: should be the water or the air pipe the inner one???

Pardal

 

[MedicineEng]

Pardal:

Are you shure that you will save money by making a heatexchanger, considering all the engineering, manufacturing, installation and running costs against an off the shelve air dryer?

 

[smckennz]

By just cooling the air to drop moisture out you may be headed for trouble. If you do this, the air leaving your heat exchanger will be saturated. Any expansion will cool the air more and cause more water to drop out, possibly somewhere you dont want this to happen.
It may be advisable to add some heat to the air after cooling. This can be done by using the incoming warm air to heat the outgoing cool air by using another heat exchanger.

Cheers

Steve

 

[pardal]

Hi Steve , thanks.
Yes I will reheat the air , as I have hot water in the same place.


Hi Paulo , of course I will save money , as far as the need are not so restrictive , a suitable air dryer cost about
2000 u$s , and I do not will earn any money.
The client had a third part bid , and ask me to do it cheaper.
And beside it the client has not the 2000 U$S
Building one, my profit will be a little more interesting.
And if we allways get of the shelf products, how can we improve our self???
And it shall be show I can save money, sure I will not earn nothing.













Pardal

 

[hacksaw]

isn't the air is satuated upon leaving most dryers (or coolers)?

 

[pardal]

I do not understand your question.


Pardal

 

[smckennz]

Hi Hacksaw

The only two refrigerant driers that I pulled apart both used the incoming air to heat the outgoing air. Perhaps this is done primarily for energy efficiency as it provides some free cooling for the incoming air. However it will also dry the outgoing air by reheat.
A cooler does only that (cools), so wet discharge lines can be expected - wet on the inside on cold days and wet on the outside on humid days.

Cheers

Steve

 

[hacksaw]

good point about the reheat

 

[pardal]

Ok, will I get any advice how to calculate such device??

Or at least the place I should go??



Pardal

 

[ClydeMule]

SWEP makes a small brazed plate heat exchanger for air drying. It includes a reheat connection and a condensate drain connection. It is a pretty nice little unit. Using this might be a compromise between buying a complete air dryer and building the system yourself.

http://www.swepusa.com

Clyde