To evaluate a compressed air system, you must begin at the end: What are your air requirements at the point of use? Once you determine exactly what type and how much air you need, you can begin to factor in design considerations, costs, and efficiencies.
Design considerations for your compressed air system
Careful planning is essential for smooth operation. System configuration should take into consideration both your requirements and the physical characteristics of your installation.
Air-cooled vs water-cooled
Air-cooled compressors have either integrally mounted or separate oil and air coolers. These coolers require adequate ventilation to perform reliably. For water-cooled compressors, an adequate supply pressure, volume, and quality water must be available.
Full or part load
Air compressors operate most efficiently at full load or off. Depending on your usage profile, it may be more cost-effective to purchase multiple compressors to accommodate load variations. In some cases, variable frequency/speed drive controlled units offer the best solution for part-load control/operation.
Oil-injected vs oil-free air compressors
Industries with stringent air quality requirements like chemical, pharmaceutical, or food and beverage may want to go with an oil-free air system. You can achieve this via filtration and other air treatment components but you can also choose an oil-free screw compressor for even more reliability and peace of mind.
System controllers
Air system master controllers improve the efficiency and reliability of multiple compressor systems. With microprocessor controls, they can stabilize system pressure and even track each unit's service, load, and maintenance hours.
Heat recovery
Recovering and using the heat generated by an air compressor conserves energy. Waste heat has many applications including process use, space heating, and preheating boiler feedwater.
Aftercoolers
These heat exchangers cool the compressed air and condense much of the moisture for easy removal. This prepares the air for further treatment.
Receiver tank
If you have widely varying compressed air loads, consider a receiver tank to boost capacity during peak periods. With a larger receiver tank, you can meet occasional peak demand with a small compressor and avoid high electrical demand charges.
Dryers
SECOTEC refrigerated dryers
Removing moisture from compressed air is essential for virtually all applications. Air quality requirements and ambient conditions will help determine the type and size of dryer required.
Piping
Pipes must be carefully sized and arranged to minimize pressure drop and should be sloped to drain towards a drop leg or moisture trap.
Filters, regulators, and lubricators
These should be installed at the point-of-use. Compressed air filters and activated carbon adsorbers provide your systems and processes with reliable, highly efficient protection against dust, aerosols, and oil vapors.
Condensate control
Because condensate must be expelled from the system for reliable operation, drain traps should be included in the system plan. Additionally, most localities require that any oil be separated from condensate before the water can be disposed of in the municipal system.
Booster compressors
Booster compressors efficiently increase plant air pressure for equipment or processes that require up to 650 psig.