Insulating Compressed Air Lines

[etw85]

We are having a problem with water in our compressed air lines. We currently have a refrigerated dryer in building "A" to extract moisture from the air exiting the compressor wich works great. The problem is in building "B" where our air lines run from inside building "A" to the outside to inside building "B". The air line is not insulated outside. Can simply applying insulation to the air line outside solve this problem? Of note the company president is not keen on buying another compressed air dryer in these tight economic times, that was my first idea.

 

[rneill]

Calculate the dew point of the air leaving building "A" and then do some heat loss calculations with and without insulation to see what difference the insulation will make. If that doesn't solve the problem, then look at some heat tracing as well.

There is no way for us to answer this question since we don't know how close to dewpoint the air is, nor what the ambient temperature outside is, nor the length of the pipe.

You need to keep the air at a temperature above it's dewpoint. If the insulation will do this, it will work but if not ...

 

[TenPenny]

A classic (read, cheap) solution for water in air lines is to run them outdoors, uninsulated, put a dirt leg in the line, and stick an automatic drain valve on the bottom of it.

Generally speaking, you want to get rid of the water in your lines, so the fact that water is dropping out is not necessarily a bad thing, you just need to get rid of it, now that it's condensed.

 

[zdas04]

Yeah, the key issue is getting rid of the water in some convenient location. The chiller in this case. Adding a manual blowdown between buildings is not the greatest of ideas (how often will it actually get blown down?). Adding some sort of sump and automated dump is expensive when the system already has a refrigerated dryer that "works great".

You can probably prevent all condensation between buildings by adding both heat trace and insulation. The math that rneil proposes can help you decide if you need the heat trace for steady flow or not, but service-air tends to be start/stop and during the "stop" part of the cycle the air will cool even with insulation. A little bit of heat trace can make a huge difference.

David

 

[mtngreen]

Use one of these for water removal....cheap and simple.

http://www.drain-all.com/