A farm implement manufacturer had a system of three large 150-hp compressors that were air-cooled lubricant-injected screw compressors. To control these compressors — two of which were needed for peak duty on any given day — the compressors were set up in a cascaded pressure band arrangement, with each unit running in load/unload mode. In […]
Air Compressors
Compressed air fail: Frozen lines
A wood products company had some troubles operating its compressed air system in the coldest winter months. Maintenance workers found that the pressure at various points in their plant would fall to very low levels, especially after weekend plant shutdowns. The plant had a system of lubricated screw compressors with refrigerated air dryers to condition […]
Compressed air fail: A holiday miracle turns bad
A metal processor had a four-compressor system that was well controlled by a compressor sequencer. System operation was very well monitored by a system of pressure, power, and flow instruments that fed system operating characteristics back to the maintenance supervisor. One day before the Christmas holiday, the supervisor noticed that the variable speed drive (VSD) […]
Compressed air issues: Bag method leak estimator
Have you ever wandered through your plant on a down day and found that it sounded like a pit of vipers with noticeable compressed air leaks hissing away constantly? Have you wondered how much money you are losing because of the leaks? Now you can answer that question armed with a simple trash bag and […]
Compressed air fail: Turn on to save
In the compressed air world, there are quite a number of energy savings features available to be installed on air compressors and air dryers. Often, these cost a premium to buy — but will very quickly pay for the added cost through reduced electricity bills. A recycling facility purchased an energy efficient heated blower style […]
Six simple ways to improve your compressed air system
By Ron Marshall Compressed air is one of the most expensive ways to supply energy to facility tools and equipment. This is due to the inherent inefficiencies in the process of compressing air — the biggest product is heat and the secondary output is compressed air. While this is disappointing, there are still things that […]
Why is compressor control important?
When controlling screw compressors, the goal is to try to keep all the running compressors fully loaded except one. And the one running partly loaded (called trim) is selected as the one having best part load efficiency characteristics. When there are only two or three compressors in a group, it is quite easy to set […]
How do you adjust dew point on air dryers?
Question: I need your advice about how to adjust the dew point for the dryers which are equipped with a dew point controller. Also, for those not having a controller, how can we determine which dew point is the best setting — -40 or -70? Answer: This is a complicated question. The method for adjusting […]
Compressed air fail: Ventilation design
A plastics manufacturer was having constant trouble with his desiccant air dryers. No matter what he did, they would constantly set off dewpoint alarms, which was very annoying. He called in a compressed air auditor to have a look. The auditor shot temperatures and found that the discharge of the compressors was too hot. Outputs […]
Service truck equipment study reveals overwhelming preference for rotary screw air compressors
VMAC surveyed 340 people in the service truck industry in 2022, asking them questions about their fleets and service truck equipment. The data shows 80% of professionals prefer rotary screw air compressors over reciprocating air compressors on their service vehicles. The 2021 and 2020 survey results also indicated a strong industry preference for rotary screw […]
