Dumb compressor question o' the day

[Beerhippie]

We've been worried about the health of our IR UP6-5-125 5 hp rotary screw comp w/80 gallon reservoir. Either we have some serious leaks around the brewery that I can't find, the comp is not outputting enough air--but used to--or it's something wrong with our canning line that keeps shutting down with a "low pressure" warning.

I just isolated the comp from the rest of the system, blew down the 80 gallon tank and timed how long it took to bring it up to 125 psi: 3:30 minutes. That sounds good to me, but how to convert that to a standard CFM at like 90 psi?

Comp data plate claims max CFM of 18.5 @ 2,000 rpm.

 

[N_Jay]

Math.
Convert tank to Cubic Feet. 10.7
Convert gage psi to Atmospheres.
At that point your pump should add 1 ATM for each tank CF/minute.
18.5 CFM is 0.31 CF second
So every 35 seconds you should see a one ATM rise in pressure

 

[Beerhippie]

Math.
Convert tank to Cubic Feet. 10.7
Convert gage psi to Atmospheres.
At that point your pump should add 1 ATM for each tank CF/minute.
18.5 CFM is 0.31 CF second
So every 35 seconds you should see a one ATM rise in pressure

Going by that, it should take about 5 minutes to bring the res up to 8.62 Bar. If the comp with 12K hours is putting out almost a third more air than its maximum rating, I'll be damned.

Anyhow, I guess I'm feeling pretty good about 3:30 to fill the 80 gal. res to 125 psi. I'll look elsewhere for the problem.

 

[dscheidt]

Anyhow, I guess I'm feeling pretty good about 3:30 to fill the 80 gal. res to 125 psi. I'll look elsewhere for the problem.

do you have a pressure gauge at the canning line machines? How does it generate the low pressure alarm? if it's an electronic sensor, that's where I'd start....

 

[Beerhippie]

do you have a pressure gauge at the canning line machines? How does it generate the low pressure alarm? if it's an electronic sensor, that's where I'd start....

There are miserable little tiny gauges on the machine. I guess the first thing to do is put a real gauge on it.

I'll find out where and what the sensor is tomorrow. Minimum pressure for the line is supposed to be 90 psi. The IR cuts in at 100 psi and out at 125. We have a total of 220 gal. of air storage.

If we run our ancient DVB recip comp, which cuts in at 125 and out at 150 psi, the canning line is happy--but it's been running just fine on the IR alone for years until recently.

 

[willf650]

I would add a pressure transducer and get something to trend the pressure in 1 minute or better intervals if you don’t have something that can do it.

I assume the canning line has a plc you can wire the transducer into. If not there is a little device called a hobo that can read the transducer and trend it for you to get a real sense of what the issue is.

We all could use the help of a hobo

 

[micromind]

After an actual pressure gauge is added to the canning line, preferrably close to the low pressure switch or sensor. If the gauge pressure stays above 90, then I would suspect the low pressure sensor.

If it dips below 90 then you'll need to work backward to the compressor and find out if there are any leaks.

If the pressure dips below 90 at the compressor but goes back up once it starts pumping then the output is ok but the time from demand to full pump output is too long. Look for gummed-up control (modulating) valves and/or small leaks in the control piping.

 

[dscheidt]

Another possibility is that something is restricting flow, and the running pressure is low. Are there any valves that might be part closed? Or new fittings?

 

[Beerhippie]

I would add a pressure transducer and get something to trend the pressure in 1 minute or better intervals if you don’t have something that can do it.

I assume the canning line has a plc you can wire the transducer into. If not there is a little device called a hobo that can read the transducer and trend it for you to get a real sense of what the issue is.

We all could use the help of a hobo

Isn't this why we spend ridiculous amounts of money to buy things like canning lines? So, like, we don't have to build it ourselves?

Truth is, we're all beta testers in this world. Janky **** gets sent out and we find out what's wrong, then the "big brains (who would have done a better job the first time if so big)" figure out how to fix it... rinse, repeat.

Imagine if you bought a car that you had to return to the dealer every few months as other users find flaws in the desi... oh, forget it.