New compressed air tech to improve efficiency and operations

PS: I wanted to ask you about a metric that CAGI is promoting recently. I know they've focused on isentropic efficiency as a more precise rating than specific power. For those of our listeners who aren't aware of that change or that push, could you give us a description of why CAGI is doing this and what advantages isentropic efficiency would have as a rating?

RM: Yeah, it's pretty exciting, I'm not part of CAGI, but I certainly use their information, their training, their guidebook, they've got a nice handbook available. One of the really exciting things years ago was third party verification, where members of the third-party verification program put their machines on for test, and CAGI went and verified the test data for all the compressors, the published data. And the agreement was that the manufacturers published their CAGI data sheets for all their machines and air dryers, some ranges of sizes of air dryers.

On those sheets were some efficiency numbers, right? We call them specific powers, so kilowatts per 100 CFM for people in North America. But the problem with that number is that you take kilowatts and divide by a CFM and it depends on the pressure you test the machine, right? Some machines are rated at 100, some are rated at 125, some 150, and so because machines consume more power per unit, naturally – it's all physics for the higher pressures – when you went to compare units, say you compared 100 psi unit with a 125 unit, the 125 unit would have higher specific power. So it looked like that unit would be more efficient, but it actually wasn't.

Now, if you if you take isentropic efficiency – and isentropic efficiency now is part of the CAGI sheet down at the bottom of the sheet – it takes that pressure adjustment away so that it's not sensitive to pressure. So then you can take a look at your isentropic efficiency across all kinds of different pressure ratings and see exactly which compressor is more efficient than the other, when you're comparing Brand A, Brand B, Brand C, Model A, Model B, you know.

It's pretty exciting for people that work in the industry and I'm specifying compressors, I can see which ones are most efficient. You can do your business case and calculate how much it's going to save and all that. It's just that one number that you can take a look at and quickly compare. And it's a kind of a different number, you know, specific power might be 18 kilowatts per 100 cfm, but with isentropic efficiency a perfect compressor (which none exists) but a perfect compressor would be 100%, right? And a very efficient compressor might be 85%, and an inefficient compressor might be 60-65% right, compared to a perfect compressor.

It's a really good development in the industry. People are starting to take a look very closely at the efficiency. The electricity costs are so going sky high, that's one thing that comes into play when you're calculating the life cycle cost of a compressor, is how much energy it consumes or wastes. It's very important information so you want to get the best bang for your buck. That's kind of a strange saying for compressed air, the bang for the buck, but I always like to get that that dig in, but yeah, it's really good information.

PS: That is good information for all the facility engineers listening to this podcast, be sure to take a look at isentropic efficiency as a useful metric in how to evaluate compressor performance. Before we wrap up our conversation Ron, I wanted to get a couple of thoughts from you about technology out there. Maybe one technology advance that caught your attention on the compressor side, and then one of the instrumentation side. So let me ask you, when it comes to compressor technology advances, what's catching your attention right now?

RM: The thing that catches my eye when I go take a look at the brand new compressors is I always see some sort of cell phone antenna on them, and it depends on whether you turn on that feature or not or whether you allow your supplier to turn on. It connects the compressor controls with some sort of database in the factory. So a service provider, say that they get a phone call from you, mentioning that the compressor is overheating or something like that. Well, they can go into your compressor control remotely and see what's going on. They can check all the parameters, you can actually data log the compressor remotely, and the manufacturer’s also taking readings if you're allow it. You know, not everybody due to privacy would turn that on, but they're taking data so that they can improve the compressors. They're seeing what's happening with the oil temperature, they're trying to predict when the air ends are going to wear out and try to make some changes to their design, things like that. A lot of data is going to the manufacturers and that data is going to help them improve things. So connectivity is what's raising my attention, along with compressor controls. There's all kinds of new touch screen controls out there that measure all kinds of things.

I do a lot of data logging right when I'm doing auditing, so there's some really nice instruments like as far as flow meters go, there's instruments that are now more affordable than ever for people, developed for wet and dry air, Many, many companies developed those, they've got internal data logging now, all that stuff, very useful information. And there's various data logging instrumentation packages that have been developed by flow meter companies and other companies as well, service companies that these edge devices and cell phones connect to, so I can sit at my computer and see what's happening at my local foundry where I put some data loggers. I can help them out, I can see when things fail, I can get them to adjust their settings. We can see what's happening with the efficiency of their system or the reliability, all from remote connections. So that connectivity, there's many companies that are developing things like that where data can be captured remotely and brought back. So that's pretty exciting in terms of auditing and measuring systems.

Of course these systems can be permanent as well, and that's something that's a very important. One of the systems that I'm using is designed to connect auditors from across the world, right? So if you live in Chicago and you really like the services of a guy in Australia, you can get him to take a look at your data, and he can do a report for you and some recommendations. So the world is getting smaller when it comes to compressed air.

PS: Wow, that's actually striking that that the world is collapsing in quite that way. When it comes to the handheld instruments, is there a technology advance again which has caught your attention or something which you think is really striking?

RM: Yes. I like doing leak audits as part of what I do when I do an audit, but the acoustical leak detectors, they have an array of microphones on them that not only do you get a sound signal, but you get a video signal. They're a handheld device that's video display, and there's various ones that are that have been designed, I think there's six different companies that have that make these now. They use about 128 or so directional microphones and it forms an array, and they form a spot on a video display and it shows you where the leak is! That's one of the frustrating things when I'm doing an audit, because if all I have is a gun that points at something, I really can't tell – especially if I'm standing down on the ground and the leak is 50 feet up – where exactly it is. This tells me exactly where it is on the exact fitting.

Very useful device, quite pricy, but lots of large organizations would buy a device like this and share it between their factories. It greatly reduces the time it takes and the danger in finding leaks, because I can find leaks behind cages, the safety cages. I don't have to go in and expose myself to spinning saw blades or mechanical things, right? So it’s a really good device that's getting my attention right now.

PS: Interesting indeed. You mentioned in an article for us that if people were looking for a quick payback on an instrument like this which might be a little on the expensive side, you had found it useful for watching leaks of expensive gases. Just finding leaks in those storage units paid for the instrument pretty quickly or would come close to it.

RM: Yeah, that's right. It was a manufacturer and they used welding gases, expensive welding gases, much more expensive than compressed air. It was only it was only a 1 cfm leak that I found up in the ceiling, very difficult to identify where exactly it was because there's compressed air and argon and nitrogen and stuff like that flowing there in different piping. But that 1 cfm leak that was worth something like, I can't remember the exact number, but $25,000 annually. It's something that was so small that it never would have been detected with the normal process and we would have thought it was compressed air, but it was actually argon.

PS: I've heard that before, where sometimes there can be so much piping, and especially if the piping is very small diameter tubing, that there may be so many leaks that there may be a lot of ultrasound signals coming from the plant, and so how do you identify which one is the critical one? And this tool can help you visually pinpoint exactly which one might be worth addressing and where it is, etc.

RM Exactly, it brings you in exactly right down to the fitting that you can see. It could be an array of all the same fittings, right? And you can see exactly which one is leaking.

I've brought that one of them into a location where there's a bunch of tools being used at random, a grinder here and a drill here and all that, in a kind of a production bay. All that stuff you can very easily rule out because they're just coming on and off. You can see it pop up on the screen but the leaks stay right there – they're sitting there, they're static, and you can see exactly which ones are leaks and which ones are machines and tools. So it's great to differentiate it – it saves time, boy it really saves time.

PS: Well, to bring us back to the first point you made, for those who are looking for compressed air training, the website you were pointing to is compressed air challenge.org, correct?

RM: Yeah, www.compressedairchallenge.org/calendar and you'll see a listing of all the trainings that are going on. And if you're part of an organization that can host a training, if you've got multiple people that need training or a bunch of customers that need training, then you can actually host a training. And we have an option of doing webinars, which is really inexpensive compared to other training, and you can have an in person training. You could even have it right in the factory, if there's a suitable meeting room, right? I've done that before, so a little bit more expensive, but because you have to pay for travel and all that, but it's a much more effective training to have it in person.

PS: I appreciate your time today with us and for people looking for more information from Ron and the Compressed Air Challenge team, there are articles on the Plant Services website, including an Ask The Experts article, which was published just this past month, May 2023, and we'll put a couple of those links in the podcast notes as well for people to go to.

Ron, we covered a lot of ground today. I appreciate you updating us on not only training trends, but also what else is happening in the industry.

RM: Happy to participate, thank you.