Air compressor company Artic Driers’ Air Audit Division, which was established four years ago, monitors the power consumption, air flow, temperature, velocity and pressure dew point of compressed-air dryers and air systems.
“State-owned power utility Eskom is spending vast sums of money on building power stations while trying to get people to cut down on their energy consumption.
“We assist clients in doing so through this division, which measures how much electricity is being used to produce the air, as well as the air leakage, air usage and the quality of the compressed air,” says Artic Driers GM Allen Cockfield.
He says that compressed air, while being very versatile and a safe form of energy, can also be expensive. He emphasises that air auditing has become a vital tool for engineers in reducing waste and energy consumption.
Artic Driers has spent more than R650 000 on acquiring air audit equipment during the past four years.
“We frequently see undersized piping installed with the compressor house. This leads to pressure restrictions that create a low pressure scenario within the plant. To overcome this, operators will often start up more compressors, which further aggravates the problem, as the piping system is not capable of handling the flows.”
Compressors are notoriously expensive to operate. “For instance, a 200 kW compressor dryer will cost you more than R1-million to buy. In the first year of operation, you will spend about R1-million on electricity if the dryer runs for 24 hours, seven days a week,” he adds.
Further, air auditing can also be used for selecting new types of compressors that will be more efficient to operate. The Air Audit Divi- sion’s services include leak detection; compressor power consumption, air flow and pressure measurement; dew point measurement; oil-filtration performance monitoring; air system design; and air pipeline installation.
By reducing the number of leaks in a factory, the work done by the compressor is reduced, which saves energy and compressor maintenance costs.
Air Pressure Optimisation
Cockfield says Artic Driers has often found that clients need to redesign their compressor rooms, as the pipes are undersized and some are badly designed.
When the correct size air pipeline is installed, it reduces pressure drops, which reduces the kilowatts used. This also reduces the air velocity, which, in turn, reduces the amount of contamination at the point of use.
“The velocity of the compressed air is an indication of the friction the air is incurring on the inside wall of the pipe, which creates pressure drops in the system. If you start at 7 bar in a compressor room and the pressure at the other end of the factory is 5.5 bar, this is undesirable and wastes expensive electrical energy.
“The British Compressed Air Society would recommend a velocity of between 4 m/s and 7 m/s as a good air velocity to aim for. If you have a badly designed pipe system, air velocities can reach a speed of 21 m/s, which is way too fast,” he says.
Cockfield states that if a refrigeration dryer fails to work for three days, the amount of water allowed into the pipe network will take a month or more to dry. This means that a short period of contamination leads to a long-term problem.
“It is important to know the needs, problems and challenges related to using air dryers to avoid incurring damage,” he says
The consistency of air quality is imperative and industry bodies and plant managers are starting to realise that dry air leads to higher uptimes, lower failure rates on pneumatic equipment, prevention of air-line contamination and a reduction in instrument failures.
Artic Driers believes in maintaining the products it manufactures and assisting its clients in solving any problems they may have. It is able to provide alternative solutions, should a product malfunction.
“With the latest twelve-channel DS500 and three six-channel DS300 data loggers, we have the resources to provide compressed air data in multiaxis graphs as well as in Excel format for clients on multiple compressor houses simultaneously,” he says.
Air dew point monitoring allows clients to monitor the performance of dryers through easy-to-use plug-and-play dew point monitors.
SMS alerts can be used to inform the factory should there be a problem in the functioning of a dryer. The system is able to detect the pressure, flow, temperature, velocity, power and dew point of the dryer, as well as report on these functions.
“The cost of compressed-air auditing or monitoring is cheap, compared with the cost of compressed-air waste and substandard compressed-air treatment,” states Cockfield.
In the long term, Artic Driers is keen to engage with its clients and supply partners to promote the efficient use of compressed air and the subsequent cost reductions and conservation of energy through its air audit department.
The development of skills and knowledge of the compressed-air industry is also crucially important for the company.
“There is still a lack of understanding on how much compressed air costs and how to solve problems faced in this industry.
“Artic undertakes presentations that will inform and educate industry players about the importance of training that will develop an understanding of the needs and functions of this sector.
“We do not have these training and mentorship schemes anymore and it is a real challenge to find and employ people who have the relevant skills in our industry,” concludes Cockfield.