- #1
ti325v
- 4
- 0
Please redirect me to the appropriate forum if I have posted in the wrong place...
This stuff is FAR over my head, and I need somebody with some real knowledge of thermodynamics and heat flow...
I own a scuba dive shop and of course we compress air to very high pressure, on the order of 300 BAR.
Common knowledge is that as air is compressed, the water being incompressible condenses out.
In out compressors which are multistage (3 or 4 is normal) we have separators to remove the water from the airstream between each stage.
Of course we must make this air VERY pure, pretty darn close to laboratory pure on a large scale, thousands of liters a day.
There are a number of principle contaminants that we have to deal with in our filtration systems.
In general however, the more water we get out, the better the air will be, as we are removing the oil from the compressor, another contaminant in the process.
We typically try for dew points around minus 50 to 60 *C, or more, so this is pretty dry air !
Of course the cooler the air stream, the more water that will condense out, the better the air and the longer the life of the filter system...(Not inexpensive).
So...I have taken the air stream which is passing through a stainless steel coil, (035 wall thickness) 1/4 inch outside diameter, 12 meters long and put it in an in water bath at 0*. The air is moving through this tube at 265 liters or more a minute, so it is going pretty fast. The temperature on the surface of the coil, before it enters the ice water is about 39*C.
The temperature of the surface of the coil after immersion 20 cm above the ice water is about 5*c. By the time the air has traveled about 1 meter to the separator the surface of the coil is now at about 30* C. Now, knocking the air temp down by 10*C will nearly double the life of my filters, but...since the coil surface temperature rises so quickly, and I would be thrilled to have the air inside it at 3 or 4* when it enters the separation chamber, my question is...do I have enough coil in the ice water ? I think I am not loosing any where near the amount of heat that is possible with this method. If I can get the air stream down to 4* I will increase my filter life by about five times !
Thoughts ? questions for clarification ?
Thanks very much for any or all ideas...
This stuff is FAR over my head, and I need somebody with some real knowledge of thermodynamics and heat flow...
I own a scuba dive shop and of course we compress air to very high pressure, on the order of 300 BAR.
Common knowledge is that as air is compressed, the water being incompressible condenses out.
In out compressors which are multistage (3 or 4 is normal) we have separators to remove the water from the airstream between each stage.
Of course we must make this air VERY pure, pretty darn close to laboratory pure on a large scale, thousands of liters a day.
There are a number of principle contaminants that we have to deal with in our filtration systems.
In general however, the more water we get out, the better the air will be, as we are removing the oil from the compressor, another contaminant in the process.
We typically try for dew points around minus 50 to 60 *C, or more, so this is pretty dry air !
Of course the cooler the air stream, the more water that will condense out, the better the air and the longer the life of the filter system...(Not inexpensive).
So...I have taken the air stream which is passing through a stainless steel coil, (035 wall thickness) 1/4 inch outside diameter, 12 meters long and put it in an in water bath at 0*. The air is moving through this tube at 265 liters or more a minute, so it is going pretty fast. The temperature on the surface of the coil, before it enters the ice water is about 39*C.
The temperature of the surface of the coil after immersion 20 cm above the ice water is about 5*c. By the time the air has traveled about 1 meter to the separator the surface of the coil is now at about 30* C. Now, knocking the air temp down by 10*C will nearly double the life of my filters, but...since the coil surface temperature rises so quickly, and I would be thrilled to have the air inside it at 3 or 4* when it enters the separation chamber, my question is...do I have enough coil in the ice water ? I think I am not loosing any where near the amount of heat that is possible with this method. If I can get the air stream down to 4* I will increase my filter life by about five times !
Thoughts ? questions for clarification ?
Thanks very much for any or all ideas...