Ethanol Plant Puts Smart Sensors to Work

Commonwealth Agri-Energy in Hopkinsville, Kentucky, is using bearings coupled with sensors to monitor vibrations and temperature, giving the ethanol plant yet another cloud-connected, easy-to-install predictive maintenance tool.
By Matt Thompson | April 30, 2020

Jonas Spoorendonk, global product manager for ABB’s Ability Smart Sensors, compares his company’s sensors for mounted bearings to a fitness tracker. “You just put it on and then you get good monitoring of your condition, your steps and your calorie consumption and maybe your sleep patterns.”

In the same fashion, ABB’s sensors are easily installed and can give users data about a bearing’s temperature and vibrations almost immediately. “It’s not new in the sense that we’re doing something that couldn’t be done before,” Spoorendonk says. “It’s new in the sense that it’s become a lot easier and more affordable.” He adds that the sensors are universal. “Generally, you can get good benefit from monitoring any type of machine, having these sensors on the bearings.”

The sensors connect to the cloud and send data wirelessly. “We are doing some calculations on the sensor, and then we finalize the calculations in the cloud,” he says, adding that this method minimizes data transfer and optimizes the sensors’ battery life.

For about nine months, Commonwealth Agri-Energy’s maintenance manager, Jeff Radford, has been using the smart sensors on the plant’s hammer mills. Commonwealth is a 45MMgy ethanol plant in Hopkinsville, Kentucky.

“I’ll download what [the sensors] took for that week, and then I’ll upload it to their cloud,” Radford says. “Basically, ABB’s program looks at all the information; they’ll give me a green, a yellow or a red indication, saying it was good, warning, or red—something’s really, really bad.” He adds that he can also compare data and see trends in how the equipment has been operating over a specific period.

That analysis is a key part of how the system works, Spoorendonk says. “The analysis is a critical component because we use the equipment’s raw data, such as vibration and temperature, to calculate meaningful information on the condition and performance of the bearing,” he says. “By understanding the health of the asset, maintenance can be planned before a problem occurs.”

Radford says Commonwealth first installed the sensors on the plant’s hammer mill bearings to help monitor and diagnose vibration issues. While vibration monitoring was the primary driver, Radford says plant personnel typically monitor temperature. “It can tell us a little bit of information if we’re needing to change the screens in the hammer mills,” he says. “It’ll pick that up, so they are pretty sensitive.”

In Control
While the sensors are Bluetooth capable, they’re not yet tied into Commonwealth’s distributed control system (DCS), Radford says. But that could change. “[ABB offers] a Bluetooth-type network that you can put out there and it can automatically query these things for you,” he says. “We’re not anywhere near that right now, but if this thing works the way that it’s supposed to, we might do that in the next couple of years.”

Spoorendonk says connecting the sensors to the DCS is easy, as it mostly involves updating software. “The way you do that is through a standardized cloud interface, what the software people call an API—an application and processing interface,” he says. “This is nuts-and-bolts for the software people. You just show them where they can find it and then they can sit down and start to integrate the data.”

Dennis Uhl of Stover Controls says that while he hasn’t worked with ABB’s sensors, Emmerson offers sensors that can measure temperature and vibrations as well. Connecting those sensors to a DCS can be done in a variety of ways. “If it’s a wireless unit, that wireless unit goes to what they call a gateway, and then that gateway can send out the information via mod bus, ethernet IP, OPCUA, there’s a variety of different ways to pull that information, communicate it back to the DCS,” Uhl says.

And he says using sensors on assets helps manage equipment reliability and improves safety at plants. Measuring factors like vibrations and temperature allows personnel to recognize and respond to potential equipment failures before they become catastrophic, Uhl says. “Maybe there are corrective items you can do to extend that time before you hit functional failure and get you to a point where you have a scheduled outage or scheduled shutdown,” he says. “By identifying that problem earlier, you drive down the cases of safety-related instances. Having that plan and schedule provides a safer work environment, plus the work gets done faster.”

In addition to monitoring individual bearings, ABB offers sensors for pumps and motors. Those sensors go beyond just reporting and measuring temperature and vibrations, Spoorendonk says. “Here we are monitoring an electric motor, for example, with two bearings and other things, and we are using the information we get—including the magnetic field and vibration—to analyze the health of those bearings. So, this is a slightly more sophisticated sensor in terms of the data you are getting.” Spoorendonk adds that many customers choose to add sensors to mounted bearings, motors and pumps. “In a lot of cases, we certainly recommend using both,” Spoorendonk says.

Many customers also add more sensors after testing them during a pilot phase. “Very typically, they start monitoring one type of equipment—like the bearings—and if they like the concept, then they expand into other areas,” he says.

Being able to expand and scale up equipment monitoring is part of ABB’s wider solution for ethanol plants and other manufacturers, Spoorendonk says. “[Customers] buy the sensors because they see how we are helping them follow this path toward predictive maintenance. This is something our customers appreciate.”

And that’s true for Commonwealth, Radford says. He has plans to include four more of the Smart Sensors in other areas of the plant, including the regenerative thermal oxidizer (RTO) and dryer fans. “That’ll give us a little bit more information,” he says.

Uhl says Stover Controls is seeing more interest in sensors and predictive maintenance, but more plants could be using the technology. He says with the current margin environment, coupled with other capital expenditures, plants may not prioritize predictive technologies. “PDM technologies, a lot of times, get pushed off to the side because they don’t see the immediate benefit to it,” he says.

Predicting the Future
Spoorendonk says next steps for ABB include monitoring systems, like an electric motor and two bearings that may make up a fan assembly. The grouping of those individual components into a larger system for monitoring is called a power train, Spoorendonk says. “[These individual assets] belong together in a bigger assembly, in a bigger unit,” he says. “So the power train is looking for anomalies: if the motor is doing this, then the bearings should be doing this. This is a very big step going forward—progressing from this stage where we are looking at individual assets to the next level where we are looking at assets that belong together.” He says the technology is available for plants now, but further development is ongoing.

And, Spoorendonk says, while predictive maintenance is an ever-advancing area of the industry, the technology, in many cases, isn’t up to expectations. But, he adds, sensors like ABB’s are a step closer. “[Customers] buy the sensors because they see how we are following this path toward predictive maintenance, and this is something people are appreciating,” he says. “New features, new functionality are coming. And I think this is pretty important also for them because they need to adapt their ways of working.”

Author: Matt Thompson
Associate Editor, Ethanol Producer Magazine