One hidden problem in many compressed air systems is something called “artificial demand.” Many users are unaware of the effects of this component of compressed air demand as evidenced by higher than needed compressed air pressures on most systems. Artificial demand in a compressed air system refers to the excess consumption of compressed air caused […]
Air Preparation
Compressed air fail: Expensive air conditioning
Compressed air is useful for very many important tasks in facilities. However, due to the high cost of producing it, there are some end uses that are very wasteful. Air conditioning and ventilation is one such inappropriate end use. In a recent survey, a compressed air auditor found a surprisingly unique waste of compressed air […]
Compressed air fail: Corrupted VSD settings
When the equipment is new and set up correctly, the coordination of VSD air compressors with fixed speed units is quite easy — if the number of compressors in the mix is four or less. Typically, what should happen is the VSD compressor maintains trim position with all combinations of fixed speed compressors providing base […]
Compressed air fail: Hidden filter
A compressed air audit at a metal parts painting plant yielded some puzzling results. Pressure loggers were placed at the compressor discharge and in the plant, but the readings were showing an unexpected and significant pressure drop between the instruments. Visual checks showed that the only thing between the loggers was an air dryer with […]
How do you become a CAGI Certified CCASS?
By Ron Marshall You may have noticed some email signatures displaying the Certified CCASS symbol — and have become curious as to how that’s earned. Anyone, if properly prepared, can become certified by writing and passing an exam. The ease in preparing for the CAGI (Compressed Air and Gas Institute) Certified Compressed Air System Specialist […]
Compressed air fail: Dryer balance
A compressed air auditor was monitoring a system in a plant that produces plastic film. Part of the measurement involved analyzing the flow from the compressor room and the dewpoint of the compressed air. When examining the data, a strange pattern developed on the flow and dewpoint profiles (Fig. 1). We can see the output […]
Compressed air fail: Unexpected water
It’s always frustrating to find water in a compressed air system, and especially so in locations where the air is supposed to be dry. During a recent compressed air audit, a survey of the piping found that poor dewpoints were being experienced in the system. Investigation found that significant amounts of free water mixed with […]
Compressed air fail: Extra heat
Most of the energy that goes into an air compressor comes out as heat, so it is always a good idea to direct the hot air produced to a location that needs heat — like into a plant in the winter season. The compressor in the photograph has a specially designed heat recovery system that […]
Compressed air fail: Bad water
Water-cooled compressors can have an advantage in locations where the ambient conditions are hot — and therefore using air cooled compressors would result in discharge temperatures that exceed the capacity of the air-drying systems. Overloading air dryers could result in free water entering the plant piping system. This would cause contamination of connected machines and […]
Compressed air fail: A rat’s nest of wiring
An air compressor at a metal processing plant had a troubled life. It started out as a VSD controlled machine, but a fire damaged the controls. Because of this, a new VSD was installed. It didn’t match the old drive, so wiring was altered to accommodate. Next, the drive failed due to dust contamination and […]