During the live Q&A portion of the webinar “Keep cool and go with the flow: How to fix temperature, pressure, and air quality issues with your compressed air system” (now available on demand) Kaeser Compressors product manager Werner Rauer and compressed air consultant Ron Marshall tackled several attendee questions related to combating common compressed air problems.
PS: I have problems with my compressor overheating. What's the first thing I should check?
WR: It depends really on the type of compressor. The first thing you should do is check the compressor service manual for advice for your specific compressor model. On some of the more modern compressor controllers, you can check the history to see what happened in the events. They may show that somebody already reset it and tried to restart it. Then you have to be extra-cautious. You do not want to restart a compressor that has no oil or no oil pressure. Be careful if you see or feel that the overcurrent device is being tripped. The ventilation inside the room is important, as is the condition and service of the heat exchangers for water coolers. And in the end, you might want to call your local distributor if you're in doubt or if you have exhausted all of the above.
PS: Are there any precautions regarding external ventilation? Can forced air ventilation directly coupled to a compressor defeat the internal fan?
RM: I've not seen a problem like that where the external ventilation defeats the fan. Sometimes you have to go with a booster fan if you've got lengthy ducting insulation. You have to actually add a fan into the duct to get the air moving. And, don't forget that the air coming out of the air compressor is useful. You can send that air out into the plant and save yourself some natural gas cost and things like that.
WR: We highly recommend getting rid of the heat where it is created. Typically, this involves ducting the exhaust, and then you can either use it for heating something else or dump it out of the room. And the compressors typically have a fan that will provide or suck the air in that it needs. We try to stay away from forced ventilated rooms. There are some very rare exceptions when you have a facility that does not allow a negative pressure in the building. But those are typically the exceptions.
PS: Do you think that adapting the IIoT with the centers associated with that, as well real-time data and an historian, could help address problems and help a plant schedule maintenance and find out root causes of most of the problems?
RM: I would highly recommend that any industrial plant have some sort of monitoring system that can be used when there are problems happening in the plant. These problems can include something as simple as pressure problems, dual point problems, (or) temperature problems, or as advanced as calculating the specific power. That's like the gas mileage of the system. Many companies have these built into their compressor control monitoring systems, allowing me to sit at my desk here to find out what my customers' air compressors are doing. In fact, sometimes I find out about the problem before the customer (does), and it amazes power-house supervisors that we can detect problems before they know about them.
PS: What kind of piping do you recommend to prevent contaminant buildup?
Before retiring in 2016, Ron Marshall was the industrial compressed air systems expert at Manitoba Hydro, where he worked for 38 years. His efforts supported the organization’s Power Smart Performance Optimization Program. He now operates his own compressed air energy efficiency consulting firm and is a member of the project development committee at the Compressed Air Challenge.
WR: I don't know whether you remember the movie "Moonstruck, "but there's a scene where the dad, a plumber, states, "There's all kinds of material and then there is copper." For compressed air piping, there are several good choices. Stainless steel, aluminum, and, yes, copper, are all good choices. We see quite a few people trying to go cheap with regular steel, in particular. In the long run, you get what you pay for.
RM: It's terrible to see people using black iron pipe or something like that. They have super-fine filters attached to their air dryer and very high-quality air going out into the system, but the air is picking up all the particles from the inside of the piping and sending it off. So all that money you spent on filtering and an air dryer is wasted if you don't have a proper-quality pipe.
Werner Rauer is Kaeser Compressors' product manager for rotary screw compressors. He has a degree in mechanical engineering and has been with Kaeser USA for more than 30 years. Rauer is a frequent speaker and writer on compressed air system technology and system improvement. He currently chairs the rotary positive engineering committee for the Compressed Air & Gas Institute.