Compressed Air System / IIoT

New and (actually) improved: Compressed air innovation in focus

New data collection and storage functions promise to deliver smarter control and better efficiency.

By Ron Marshall

One of the notable highlights of this year’s Hannover Messe trade show in Hannover, Germany, was a focus on enhanced efficiency and reliability of compressed air systems. Product improvements, including wireless and cellular communications links, were showcased seemingly everywhere, from the most complicated compressor controllers to lowly but important condensate drains. Particularly exciting developments were found in the control and monitoring of air compressors.

Compressor controls and sequencing controllers have been steadily advancing over the years from simple relay logic to complicated microprocessor-based systems. These devices typically operate on an internal design logic that will control compressors based on preprogrammed set points, with the control making a change to system operation based on one or more parameters that might vary past a programmed limit. These controls have various other functions to monitor and report faults in the system or to remind operators when maintenance is due based on some internal timer function.

At Hannover, four companies featured noteworthy product developments. All four have developed or enhanced control, analysis, and communications tools that can help compressed air users keep their system running reliably and at the highest efficiency. 

Sullair announced a communications and monitoring system called Sullair AirLinx (see Figure 1). Released in conjunction with the launch of the company’s newly redesigned LS90-110 range of compressors, the system provides a cellular data link from each compressor controller to a cloud database. This link allows remote monitoring of key compressor parameters by computer, tablet, or smartphone, and, if desired, immediate reporting of problems to key plant personnel.

On-board the redesigned compressors is a new Sullair Touch Screen controller that provides enhanced visualization of all compressor internal conditions and that features a redesigned compressor sequencer that can efficiently control a group of compressors with similar controls. This controller is smart enough to take control of onboard spiral-valve variable-capacity controls (if present), and in a system of multiple compressors, it will coordinate multiple spiral valves to give VSD-like control on a single pressure set point. This allows customers with compressors located in extreme environments that would not allow the installation of VSD controls to have excellent pressure regulation and optimum compressed air system efficiency.

Kaeser Compressors had its enhanced Sigma Air Manager 4.0 on display (see Figure 2). Operating within a Kaeser Sigma Network, this control system offers many enhanced communications and data analysis features. The network connects all site compressors together, forming a high-speed data highway within the plant that provides optimum control and monitoring of connected compressors. Designed with user interests in mind, the controller is shipped preprogrammed to the customer, and when installed, it will “learn” the characteristics of the system, such as storage volumes and compressor response times. Based on this information, the controller will take things like pressure rate of change, compressor idle time, compressor unloaded kW, and unit cycle times and use this information to make decisions about how to control compressors to provide optimum operating characteristics.

This provides not a fixed pressure band as with traditional controllers but a flexible band that works within set user defined minimum and maximum limits. The network can be connected to a Kaeser cloud server that collects key system data allowing compressed air users to monitor their systems via any smart internet connected device. Alerts can be automatically sent to compressor operators and service personnel if parameters cross preset limits.

Energair Solutions from CMC announced its new product, called the Compressor Gate (see Figure 3). This stand-alone product will initially not control compressors but is designed to work to monitor any brand and type of compressor to provide affordable continuous monitoring via broadband cellular link of key compressor parameters. The keys to the system are 4G-linked communications modules that are installed within each compressor as a retrofit. These modules capture parameters like operating status, temperatures, pressures, and alarms and send them to a database server.

The company also offers a module that takes three-phase power readings of the compressor input – it’s one of a few companies that uses actual measurements rather than calculated values for monitoring purposes. As with other vendors’ offerings, the data resides in a cloud database that can be accessed from anywhere in the world. Corporate energy managers and key operating personnel will be able to query their connected sites worldwide to track energy performance, reliability, and maintenance functions to be able to keep their systems running smoothly.  The company also offers compressor controllers and a line of compressed air auditing instruments called SCADAR that offers cloud-based data processing and automated reporting to help company energy auditors make sense of the collected data.

Airleader, a family-owned German company, showcased its Airleader master control and online monitoring system (see Figure 4). The company has developed a new touch-screen and wireless interface and adapted it to an already highly developed control system. Always ahead of the curve, Airleader has integrated data collection and offered cloud-based reporting as a key part of their portfolio for many years. The controller system features an in-plant interface that connects to an Ethernet system so the user can see real-time performance of their system via web page.

Also, a connection to a cloud-based server, either through a company firewall or a broadband cellular connection, allows the collection and uploading of key system data. This allows for very useful analysis and reporting of system problems, pending maintenance needs, and system energy efficiency. This control system is designed to work with any make and model of compressor and will monitor other system components like flow meters, kW meters, and air dryers. Interface to variable capacity controllers such as spiral valves, turn valves, and poppet valves is also possible. Airleader also offers a device that can be installed on a compressed air system to monitor system operation and determine if a compressor controller is warranted. Data taken from this device can be used, for example, to find areas of inefficiency, measure leaks, and troubleshoot problems, all functions the control and monitoring system does on a permanent basis.

What does this mean to the user?

These new enhancements will have a significant impact on the compressed air user.  In compressed air systems, like other systems, measurement of important parameters is key.  “Our motto is if you don’t monitor it, you can’t manage it.” says Jan Hoetzel, manager of SIGA Development, the distributor of Airleader compressed air management systems in North America. “That’s why we provide a web server with all of our systems that makes the operation of the compressed air system transparent to user.  Knowing how the system is operating opens the eyes of the user to system inefficiency, takes the uncertainty out of future improvement projects, and makes management more willing to go the next step in correcting their system operation.”

But simply monitoring a system is not always the final answer. “A lot of customers monitor their systems but never look at the data,” notes David Booth, system specialist at Sullair. “We’ve found that a quick scan of the system data by system experts at about a dozen of our beta sites showed really obvious problems, like VSDs running in base load. One site saved about $40,000 per year by simply readjusting the parameters.”

Intelligently using the data can yield big savings. “We installed a master controller on five compressors, four FS and one VSD, located in five different areas across an agriculture implement plant,” explains Nicolas De Deken, COO of Energair Solutions. “While the master controller was performing as it should using fixed-speed compressors only as base load (fully loaded) in combination with the VSD trimming, permanent monitoring of pressures in the different areas showed that due to inadequate piping, the VSD had to run at 125 psi to maintain a 100 psi minimum pressure throughout the plant.” He continues: “This analysis allowed us to calculate the ROI of investing in better piping, through a closed loop, and after the new piping has been installed, the VSD is now running at 105 psi, providing additional energy savings.”

The data collected from such systems is really useful to management, especially if there is a corporate energy management system in place. ISO 50001, for example, might lead the company to designate the compressed air system as a significant energy user (SEU). Once an SEU is identified, the company managers must then implement an energy tracking strategy. This is where having a compressed air monitoring system becomes important.

“One of our customers was being encouraged to purchase a new compressor to solve a shortage of compressed air,” says Jan Hoetzel, “but since data was available from our monitoring system, the company controller in the finance department got interested in the plant leakage flow numbers.” Hoetzel continues: “Through his efforts and his ongoing pressure to reduce this waste and implement other system improvements, the company was able to reduce their flow from 3,500 cfm to 2,300 cfm and optimize compressor control, saving them about half a million dollars in operating costs.”

These are quite impressive results. Hoetzel tells of another third-party-verified installation that saved 84% thanks to the more-efficient control of the system compressors. Having system data available after the compressor control system was installed helped save an additional 71% of the remainder once the system’s operation could be permanently monitored.

“System monitoring is very important,” says Jarno Manzke, technical director at Kaeser Compressors. “A wire manufacturer allowed us to monitor their compressor, and the resulting project saved $45,000 per year. The compressor monitoring system that was installed helped verify the results because it collected all the necessary information.”

Monitoring of the data can be extremely effective in improving systems and keeping efficiency as high as possible, but data collection and storage provides other opportunities, too, not only in verification of savings but also with respect to system reliability and predictive maintenance.

“We are collecting a large amount of data about every connected compressor,” Manzke says. “This allows our company to do some data mining that will help us, for example, predict future compressor air end failures before they happen. Use of the data will allow us to recognize changing conditions inside our compressors and notify service personnel and compressor operators well before major damage to the compressor takes place.”

All of the companies interviewed indicated they were planning to use database information to further enhance system monitoring’s benefits for their customers. Added Manzke: “We’ve developed a system that tirelessly monitors the data, and once programmed with special algorithms, can flag many reliability- and maintenance-related issues for our system experts to review. And our control system currently works like a chess computer, looking ahead and simulating possible better compressed air system operation. If system monitoring identifies improvements that can be made, then our personnel will better be able to contact our customers with a solution.”