Apart from the air compressor, which is the main power plant for the generation of compressed air, effective, efficient and reliable industrial systems depend on other components to ensure the delivery of sustainable, contaminant-free air to the end-use application.
The ideal configuration and integration of the system components is vital for the enhancement of overall performance and low-maintenance, durable operation.
An air receiver, sometimes referred to as a compressed-air tank, is an integral and vitally important part of all compressed-air systems. The receiver acts as storage for excess air to accommodate the peaks of demand from your system and to optimise the running efficiency of your compressor.
Short-term, high-demand periods are catered for while reducing pressure drop throughout the system and protecting the integrity of critical pressure applications at end use. Adding air storage capacity to your system decreases loading and unloading demands on the compressor, thereby reducing wear and tear, extending cycle times and cutting energy costs.
The most common example of compressed-air receivers is seen with the small, reciprocating, rotary-screw or scroll-type compressors, mounted on a “tank” or air receiver. The compressor operates on a start/stop, load/unload or VSD control system. Receiver-mounted air compressors are ideal for use in small-to-medium demand applications where space is at a premium.
In larger industrial applications (usually rotary screw-type compressors), receivers are usually separate vertical-standing units placed in the air supply line along with dryers, oil-water separators and filters. The compressors typically cycle utilising either a load/unload or variable-speed control system.
In some engineered circumstances, an air receiver can even continue to supply air while, if required, production plant and equipment is safely shut down.
Air receivers make compressed-air systems more energy efficient by allowing the compressor to operate on longer cycle times and with tighter pressure bands. The bigger the air receiver, the more efficient the system.
Air dryers are essential for air compressors. Water present in the atmosphere, in the form of vapour and aerosol, is difficult to remove. When compressed, this vapour will condense, allowing liquid to form. Accumulation of this moisture over time can cause serious damage to the compressed-air system, such as corrosion, machine damage and product spoilage. Malfunctioning of control components, in turn, can bring the production processes to a halt, or impair tools, leading to additional maintenance and time costs. As such, air dryers need to be given due importance.
There are two types of air dryers – desiccant and refrigerated. Desiccant air dryers are particularly valuable when a very low-pressure dew point is required for sensitive applications. Refrigerated types are more common for industrial applications where dry air is needed, even in the hottest conditions.
Investing in a good air dryer will not only ensure your compressed air yields better returns for longer but also help increase your production levels by reducing equipment failure problems due to moisture, reduce loss incurred due to moisture-ruined equipment, and increase overall profits of your business. In short, air dryers are worth every penny spent.
Compressed-air coalescing filters protect end-use equipment from dust, dirt, pollen, oil, water and other contaminants. Contaminants can damage your equipment, especially when the dirt and dust is combined with oil (which is often the case with compressors). Contaminant build-up can form inside valves, motors and other compressed-air equipment. Compressed-air filters integrated along the air lines between the compressor and end use offer a high degree of protection against wear and tear.
Quality air filters have a lower pressure-drop than low-quality ones. This will save you energy. Every pressure drop in your system (from filters, dryers, long piping and so on) will require you to set your compressor on a higher setpoint, which will cost you extra electricity.
Particulate compressed-air filters remove dust and particles from the air. These particles are collected in the filtration material, where they stay until the filter is replaced every few months, depending on operation time and application. Clogged filters increase pressure drop and make filters less effective in removing contaminants.
Coalescing filters are used to capture oil and/or moisture that is suspended in the compressed air in very tiny droplets. Unlike particulate filters, the filter material collects the small droplets and transfers them to the bottom of the filter, where a condensate drain removes the liquid. Coalescing filters also need to be regularly replaced as contaminants slowly build up in the filtration material.
Compressed air flows from your air compressor to the end-user equipment through your compressed-air pipeline. It is important that the type of piping is suited to the application and flow and that the pipe bore is large enough to handle the demand and system pressure. As all compressed-air systems will suffer some degree of pressure loss through the pipe system, the type, length, layout and installation of the piping are also very important. There are a few things to keep in mind when installing compressed-air piping, such as water, rust problems, the position of valves, the position of connections and filters, and many other factors. The most common pipe used includes:
PVC: The use of PVC pipe is common but not generally recommended for use with compressed air. While readily available, inexpensive, and easy to install, PVC can sag over time and will require additional supports. The presence of air-compressor oils in the line from the compressed air can accelerate the degradation of PVC.
Copper: Copper pipe is commonly recommended for clean air. While it works very well, it is expensive and more difficult to install, because the soldering of joints is time consuming and requires a high degree of skill.
Aluminium: With easy-to-install connections, aluminium piping systems are highly recommended for compressed-air lines. Aluminium is lightweight, making it easy to handle, and it is highly recommended for most air applications. It is smooth bore, non-corrosive, and usually remains leak-free over the life of the system.
Quality oil-water separators remove lubricants from condensate for easy, responsible disposal. During normal function, air compressors produce small traces of oil-contaminated condensate. This moisture collects mainly in air receivers, coalescing filter bowls and moisture separators, making it easy to discard. This liquid cannot be discharged into storm water or onto the ground and must be specially collected in order to protect the environment. Because of this unavoidable by-product of using compressed air, an oil-water separator is necessary and beneficial for environmentally responsible companies.
Auto-drain systems drain out the water that accumulates in air-receiver tanks, air dryers, coalescing filters and other low points in the air-reticulation system. If this condensate is not drained out it can enter the reticulation system, causing damage to pneumatic equipment, valves and actuators, and result in product spoilage.
To drain out the water, some systems use a timed drain. Other types use float switches or level sensors to drain out water after it reaches a certain level. Ask your Kaishan specialist about which drain is the right one for you.
Centrifugal condensate separators remove condensed moisture from the air. Since there is always moisture present in the air, condensate in compressed-air systems can’t be avoided. During the compression process, the air is heated then cools as it passes through the system. As it nears the ambient temperature (approach), vapour condenses to liquid and can be removed by mechanical separation utilising a condensate separator.
Servicing and maintaining system components is vital to operator productivity and cost saving.
While thousands of businesses are dependent on compressed-air power, it is obvious that many do not fully understand the importance of maintaining the components to maximise reliability and performance. From the compressors to the delivery piping, it is vital to keep every component leakproof, contaminant free and operating at peak efficiency. Any air leak, degradation, blockage or failure at any point can cause major problems in the system itself and may impact the end application, product or process. System breakdown also means extended downtimes, production loss and costly repairs.
With input power costs increasing, the selection of quality components from energy-saving compressors right down the line is critical to ensure reliable, efficient and cost-effective operation.
System maintenance and repair services such as those offered by Kaishan Australia are a great investment in the sustainable, peak-performance operation of all types and makes of compressed-air equipment.