What you need to know before buying an air compressor
To select the right air compressor for a specific industrial facility is indeed a difficult task. In this article, we tell you what to consider for selecting the most suitable compressor for your unit.
Air compressor are integral to almost any utility or manufacturing plant across all industries like - manufacturing, pharmaceuticals, chemical processing, and food and beverage to name a few. However, the decision to choose the right compressor system for a particular industrial setting, application, and requirement can be quite challenging. With an extensive range of compressor technologies available on the market, it certainly gets overwhelming for any buyer to pick the most suitable option for his industrial facility. In this article, we discuss the points to consider for making the right purchase decision.
1. Air Compressor Types
Compressors are broadly categorized as Dynamic or Displacement type depending on the principal of compression.
In dynamic compression technologies like axial or centrifugal are used.
For displacement compression, technologies widely available are rotary or reciprocating type.
Dynamic compressors can be energy efficiently when used for generating large volume of compressed air at stable pressure.
Axial compressors are comprised of multiple stages of rotating and is used to handle very high flowrates at low discharge pressure.
Centrifugal or radial flow compressors are used in applications that entail long duty cycles with high compressed air volume. In this technology impellers are used to accelerate air at high speeds and convert this to pressure energy. This technology is also referred to as TURBO compression and is highly cost effective per m3 of compressed air generation for large flow requirements at constant pressure.
On the other hand, we have Displacement technology for variable pressure and constant volume needs. This can be usually either rotary or reciprocating. Rotary is used for stable volumes and is well-known for its efficiency on medium pressure applications and longer lifetime, while the Reciprocating is found more suitable for high discharge pressure needs, 20 bar and above.
It is important to know the type of application and requirement to have a best match on technology for an overall optimized compressed air installation.
2. Air Quality - Oil-free or Oil-injected
Based on your industry and application requirements, you must decide whether to go for an oil-free compressor or an oil-injected one. Oil-free is guaranteed Class 0 as per ISO 8573-1 with no oil contamination in the compressed air stream and can be a crucial parameter for industries like Food & Beverage, Pharmaceuticals, Electronics, Chemical, Air Separation or Paper etc. to name a few. Compression happens over two or more stages here to compensate for heat generation with interstage coolers as no lubricant is mixed with compressed air to guarantee Class 0.
3. Pressure and Flow Rate
Another prerequisite to look at while choosing a compressor for your facility is the right compressor size. On one hand, choosing a compressor smaller than your need will get no job done; on the other hand, selecting a compressor greater than your need would lead to energy wastage.
Measured in bars or pounds per square inch (psi), pressure is an important factor to consider when installing a compressor system of the right size. You must install an air compressor that provides enough pressure with some margin to account for pressure drop in the pipeline or air treatment ancillaries to accomplish a particular task in your facility. For instance, rotary screw is efficient on medium pressure applications and piston or reciprocating compressors are a good choice for pressures above 20bar.
Next, the flow rate calculated in cubic meters per hour or cubic feet per minute, or litres per second, decides the volume of air moving through your compressor. Every technology has an optimum rage - while centrifugal compressors have low specific energy consumption for high flow rates, the rotary screw or tooth compressors can be an efficient choice for lesser compressed air flow demands.
4. Noise levels
Noise reduction system is important when deciding on air compressor. This equipment is usually designed to make a work environment comfortable. Measures are considered into design towards limiting the noise levels and moreover sound enclosure or canopy is offered to reduce levels to 80 dba or less.
5. Cooling System
Compressor needs a system to dissipate heat or to prevent overheating during operation. This can be achieved by two ways – air cooling or water cooling, to take away the heat generated during compression from the inter and aftercoolers and the element. Further to reduce temperature of air and moisture content, air dryers can be installed downstream.
Type of cooling system is crucial and can impact your compressor’s efficiency and reliability. Water-cooled units are more energy efficient while sufficient ventilation is important for air-cooled installation for adequate cooling.
6. Compact design (Plug & Play solution)
Is space crunch a problem in your industrial unit? In that case, we suggest you pick an air compressor that best fits into your space limitations while supporting industrial activities.
For an industrial plant, usually the need is for stationary electric motor driven compressors. Look at a wide range of plug & play compressor equipment, including the most compact footprint available on the market, integrating filtration, compression element, coolers, main drive mechanism, self-lubricating system, condensate drains, control panel and remote monitoring system like Smartlink mounted on an industrial skid, delivered for a direct start-up at site.
Atlas Copco manufactures technologically advanced air compressor systems that stand out for leading-edge features such as Variable Speed Drive Technology and SMARTLINK 2.0 remote monitoring program. To decide which compressor would fit your requirements, you should get in touch with our expert for a discussion.