Bob Safford
Bob Safford
Photo courtesy Kaesar Compressors USA

MRF Ops Forum 2021: How to optimize compressor performance

Bob Safford of Kaeser Compressors USA discusses how proper planning and maintenance can improve compressor performance.

October 26, 2021

As the waste and recycling industry begins to use optical sorters and robotics more frequently, having a clean stream of compressed air is vital to operations. During the 2021 MRF Operations Forum, Bob Safford, senior key account manager for Kaeser Compressors USA in Fredericksburg, Virginia, discussed the importance of designing and maintaining quality air compressors. The free virtual event was Oct. 18-19, with on-demand viewing available also available for free by registering here.

Safford said good compressor maintenance begins with the design of the compressor.

“My thought is that the maintenance is always the aftermath,” Safford said. “If the design is not right, maintenance is never going to do anything.”

Safford recommended that material recovery facility (MRF) operators design and size their compressors for the scale of operation they need.

A few factors can influence the size and design of a compressor. For example, Safford said that since an air compressor uses air from its surroundings to function, any dust, dirt or even plastic particles get absorbed by it. Dust can clog the compressor’s aftercooler, which leads to a breakdown of the system or complete shutdowns.

“Intake air needs to be clean,” Safford said. “If you think about a vehicle, if you throw dirt or sand into the intake, that’s getting ingested into the motor and obviously causes issues.”

Safford added that maintaining proper temperature plays a role in protecting a compressor because the device is lubricated with oil to make sure it runs smoothly. If the compressor is being used in a hot room, the oil could burn off, damaging the compressor after an extended period. If the compressor is being used in a cool environment and cannot reach 212 F to burn off condensation in the machine, the moisture will mix with the oil and create a sludge within the compression chamber, which needs to be cleaned out.

One of the most common misconceptions Safford said he hears about air compressors is that bigger is better.

“That compression chamber is collecting a lot of moisture, and if that doesn’t get burned off, it’s a nightmare,” he said. “We’re talking a $10,000 to $15,000 service job to clean it up. Bigger is not better. The compressor needs to be sized properly.”

When a compressor is ready to be put into the MRF, Safford recommended that operators follow the installation datasheets. By following the datasheet closely during development, compressor maintenance will be easier down the line. This includes carefully considering the placement of the compressor and airflow.

“We had a customer recently that made a really nice area [for their compressor]. They designed their system to go in a nice clean spot,” Safford said. “What they didn’t account for is the trucks coming by and blowing dust into the system. They installed a filter, but that was getting clogged daily. Now the compressor is getting moved.”

Other things to consider when determining where to place the compressor include Environmental Protection Agency and local wastewater requirements as well as things that could be hazardous to personnel.

Routine maintenance for compressors includes checking for leaks and cooling levels daily as well as checking filter mats weekly. Safford said things like condensate drains and wired connections need to be checked over a certain period, such as every 2,000 or 4,000 hours.

Safford also recommended having a second compressor. This way, if the first compressor goes down for any reason, the operator can eliminate the downtime of fixing the first compressor, share workloads and even prevent complete shutdowns for repair.

For more on compressor design and maintenance, check out the full presentation.