From Aging Reciprocating Compressors to a Full Centrifugal Plant: An Iowa Case Study

This is one of our latest installations, and one I am particularly proud of.

A customer in Iowa was running aging reciprocating compressors and heatless desiccant dryers. The equipment had served them, but it was time for a plant-wide upgrade. They needed more reliability, better efficiency, and a control system that gave their operators real visibility across the whole compressed air room.

The Fischer Group supplied and installed four units as part of the upgrade. Here is what the full scope looked like.

The compressors

Each unit was refurbished to “as new” condition before installation. These are not patched-up machines: they are compressors that went through a full rebuild process and came out the other side ready for continuous industrial duty. The customer has been running them for months now without issue.

Supplying refurbished centrifugal compressors as part of a plant upgrade is something The Fischer Group does regularly. It gives customers access to centrifugal performance and efficiency at a cost basis that new equipment often cannot match, especially when the alternative was keeping aging recips in service.

Replacing heatless dryers with Bone Dry

The existing heatless desiccant dryers were replaced with TFG Bone Dry modified blower purge desiccant dryers.

This is worth understanding if you are still running heatless dryers. A heatless dryer regenerates its desiccant beds using a portion of the dry plant air you already paid to compress and dry, typically 15% or more of your dryer’s rated capacity, just burned off as purge. Every hour the dryer runs, you are wasting compressed air.

The Bone Dry design eliminates that. Regeneration uses blower-purged air, not plant air. The result is a measurable reduction in compressed air waste and a dryer that does not penalize your system efficiency to do its job.

Controls, master sequencing, and SCADA

Each compressor received an open architecture Allen Bradley PLC unit controller. The plant also received a Master Controller for sequencing all four units together, plus a full SCADA system for operator visibility and data logging.

Open architecture matters here. Proprietary controls lock you into one vendor for every future change, upgrade, or troubleshooting call. Allen Bradley PLC systems are widely supported, well-documented, and give the customer’s own maintenance team the ability to work on the system without going back to the OEM for every adjustment.

The Fischer Group has been building PLC-based compressed air controls since 1997, the first in the industry to do so. This installation puts that experience into a full plant-wide system: four compressors, four sets of dryers, master sequencing, and SCADA, all integrated under one control surface.

What the customer ended up with

• Four As New Refurbished Centrifugal Compressors running at full capacity
• TFG Bone Dry desiccant dryers with zero plant-air purge waste
• Individual PLC unit controls on each compressor
• Master Controller managing sequencing across all four units
• SCADA system for real-time visibility and historical trending

The aging recips and heatless dryers are gone. The plant has a modern, efficient, and fully integrated compressed air system, and a single point of contact for service, controls, and dryer support going forward.

If you are looking at a plant-wide upgrade or have equipment that has reached the end of its useful life, talk to The Fischer Group. We can help you evaluate the options and put together a scope that fits your budget and your timeline.

---

Learn more about compressed air controls and SCADA systems, TFG Bone Dry desiccant dryers, and compressor installation and project management, or contact The Fischer Group to discuss your plant.