FAQ / Frequently asked questions
Frequently asked questions
- Why should you ‘Use your energy twice’?
- How can you switch your compressor into an energy source and recover the electrical input energy as hot water?
- Where can you use the hot water recovered from the compressed air system?
- How much energy/money could you save?
- How important is energy recovery today?
- Which models have been certified? Is there a link with Atlas Copco’s reputed Class Zero compressors?
Why should you ‘Use your energy twice’?
On average air compressors represent 10% of the industrial electricity consumption. In some companies compressed air production can represent up to 40% of the energy bill.
By highlighting the energy recovery possibilities on its ZR oil-free screw compressor range, Atlas Copco draws the attention of industrial users to the enormous potential savings. It will contribute to the environment, the reduction of CO2 emission and the user’s bottom-line.
How can you switch your compressor into an energy source and recover the electrical input energy as hot water?
According to the laws of thermodynamics the energy used to compress air is transformed into heat. The major portion of this heat - more than 90% - remains in the compressed air and lubrication oil. A small part is lost to the environment through radiation.
However, electrical input is not the only source of energy entering the system. The suction air for the compressor contains water vapour. The heat stored in the vapour is released through condensation in the inter- and after cooler of the compressor. Typically the condensation heat, contained in the suction air, is equivalent to 5 - 20% of the electrical input energy.
The unique design of the cooling system of the ZR oil-free screw compressor with energy recovery allows to fully capture all this heat from the compressed air and oil system. As a result, the total energy recovered as hot water amounts up to 80-105% of the electrical input energy, depending on the site conditions. In most industrial conditions it will be 90 to 95%.
This feature sets the ZR oil-free screw compressor with energy recovery apart from any other compressor technology
Where can you use the hot water recovered from the compressed air system?
Customers who integrate the flow of hot water into their plant processes will in typical industrial conditions be able to recover 90-95% of the compressor electrical energy input as hot water. This hot water can be used in various applications.
Most industries can make use of hot water for space heating, showers and other such applications. However the industries that will benefit the most are those that have a continuous need for hot water and steam in their processes. Typical process hot water and steam users include food & milk processing plants (scalding, cleaning, sterilization, melting), pulp & paper industry (in the digester & evaporators, and in bleaching, pulping ), textile industry (dyeing, stabilization of manmade fibers), pharmaceutical industry (fermentation and sterilization), refineries, chemical and petrochemical plants (steam distillation, enhanced recovery, stripping, heat tracing), power plants (electricity generation), clean rooms (humidification).
The hot water or steam is normally generated using industrial boilers which consume electricity or fuels like heating oil or natural gas. When using hot water from the compressor, either directly or as pre-heated boiler feed water, the consumption of fuel can be either dramatically reduced or be eliminated. This results in significant energy savings.
How much energy/money could you save?
In the ZR oil-free screw compressor range with energy recovery from Atlas Copco, the energy savings range from 55 to 750 kW. This equals annually with 200 to 2500 tons of CO2 or 40.000 to 550.000 € of electricity or heating cost.
This has a significant impact on the environment and on your bottom-line.
Find out how much you can save!
How important is energy recovery today?
The focus on energy savings in industry is currently very important and will remain so in the foreseeable future. Energy prices are likely to increase. Concerns for the environment and sustainable development are growing. Countries and industries face stringent targets to reduce carbon dioxide emissions. The Kyoto protocol sets the standard around the globe.
Atlas Copco's ZR oil-free screw compressors with Energy recovery offer solutions for all of the above. It is a matter of industrial users taking a pro-active approach and integrating the hot water flow delivered by the compressor into their processes.
Atlas Copco’s advanced heat recovery systems are also available to fit on existing installations. Our service technicians are present around the globe to install these systems.
Which models have been certified? Is there a link with Atlas Copco’s reputed Class Zero compressors?
Only Atlas Copco’s ZR series of water-cooled oil-free air compressors from 55 to 750 kW have been certified by TÜV as recovering 100% of the electrical input energy as hot water under specific design conditions of 40°C, 70% humidity of the intake air, 20°C cooling water inlet temperature and 10 bar(e) working pressure. This is the first air compressor to receive such certification.
The ZR series of water-cooled oil-free air compressors are indeed also Class Zero certified by TÜV according to ISO 8573-1 – Class 0, meaning providing 100% oil-free air. These compressors are well-established in industry with a strong reputation on reliability, efficiency and 100% oil-free air. Today they can be delivered with Atlas Copco’s Energy Recovery systems factory-built.
For Atlas Copco customers the combination of ‘Class Zero’ with Energy recovery is possible. This offer from Atlas Copco is currently unique in industry.
Want to know more about our Class Zero compressors?
