Air Compressors: Starting at the end is the best way to evaluate which air compressor is suited to your requirements. You must ask yourself a few questions and work backwards from these:
1. What volume of air do you need?
2. What air pressure do you need?
3. What quality of air do you need: what oil, water and particulate levels are allowed in the compressed air?
When you are clear of your long term goals for your compressed air system, you can then start to consider cost, efficiency and design.
Air Compressors: Design
Designing an effective compressed air system needs to take into consideration your requirements as well as the physical aspect of the air compressor’s installation.
Full or part Load: Air Compressors work to their maximum efficiency at full load. It may be more effective to buy multiple compressors to suit the varying load requirements. In some cases, variable frequency/speed drive controlled unties will offer the most efficient solution for part load operations.
Air-cooled or Water – cooled: Air cooled air compressors can have separate oil and air coolers or they can be integrally-mounted. Air cooled air compressors require adequate ventilation. Water cooled air compressors require a quality water supply with a sufficient water pressure.
Heat Recovery: Recovering and utilising the heat generated by the air compressor is crucial in energy saving for your business. Heat generated can be used in various ways, such as space heating or preheating boiler feed water.
Condensate Control: In order to ensure reliable operation, condensate must be effectively removed from the system by using drain taps. The oil must be separated from the condensate before the water is drained away.
Aftercoolers: Heat exchangers cool the compressed air and condense the moisture so it can be easily removed.
Receiver Tank: A receiver tank can boost capacity at peak periods, in systems that have a large variation in air load requirements. A large receiver tank could suit occasional peak demand, saving on energy bills.
Compressor Controller: Controllers such as the Kaeser Sigma Air Manager are computers that use advanced algorithms to monitor the system and actively analyse the system to ensure it is working at its optimum efficiency. It has the ability to stabilise the system pressure and track each compressors service, load and maintenance hours.
Dyers: It is essential to remove moisture from compressed air. The quality of the compressed air required will determine which kind of dryer you will need. As a rule the dryer the air the more costly it will be to purchase and run.
Piping: Pipe work needs to be designed correctly in order to avoid pressure drop, and sloping towards a drop leg or moisture tap.
Filters, Regulators and Lubricators: These important components must be incorporated into the design and installed in the system. As with the dryer the rule is the cleaner the compressed air the more costly the filters are to purchase and run.
Booster Compressors: For processes that require up to 650psig, booster compressors efficiently increase plant air pressure.
You will need to determine how much pressure your plant requires. Pneumatic tools are rated by the manufacturer for their capacities at specific pressure ratings.
This is can calculated using the equation:
Pr= Pp + PL
Pr = Minimum required pressure
Pp = Pressure at point of use
PL = Total pressure loss
Total pressure loss should include losses at the dryers, separator, filters and piping and valves.
This can be determined by a professional air system audit, or by calculating the capacity requirements and load factors for each machine that utilises compressed air. This information will be available from the manufacturers of each machine.
Determining the quality of air required for your business is essential when choosing the type of filtration and drying system in your compressed air system – the better the air quality the more costly the air compressors system will be, you don’t want compressed air cleaner than it needs to be.
Air Compressor Design
Electrical Costs: Over a ten year period, on average 70% of the air compressors overall costs will be power. So investing in a more economical power saving system is likely to save greatly. In most cases, in just one year the savings could exceed the cost of the air compressor in as little as one year. It is therefore crucial to look beyond initial costs when choosing a compresed air system.
Maintenance Costs: The easier the air compressor system is to maintain, the bigger savings in the long run.
Leaks and Unnecessary Demand: Leaks in the compressed air system will obviously cost money, and over production or unnecessary use of compressed air will waste money.
Reliability: When the air compressor system is not working, it’s costing your business money, so it’s always paramount that the system will be as reliable as possible.
Glaston’s engineers will make a full assessment of your requirements to design an air compressor system which is right for your business. Contact us today for a tailor made compressed air solution.