Electrically driven compressors heat industrial premises

Many industrial processes require compressed air to drive, drill, spray, pump or control advanced production machines. In general, almost 10 percent of total energy consumption in a normal factory is used by compressed air systems. Unfortunately, the pressurization of the air leads to energy losses in the form of heat loss. Atlas Copco has solved this dilemma with a compressor that can recover 100 percent of the input energy necessary for compressor operation.

Wasted heat in industry

Usually, electric compressors pressurize air on a big scale at the right quality and pressure. Most people who have hand-pumped a bicycle tire have felt the heat produced when the air is pushed into the tires. With industrial compressors, the same phenomenon occurs, albeit on a larger scale.

This means that large amounts of energy are lost to no avail. But many industrial premises have heating needs for buildings, and sometimes also need hot water and steam for different processes. In many cases, these needs are met with the usage of electricity. To summarize, there is a disconnect: a heat loss from the compressors, and a need for heating.

To reduce energy losses, Swedish company Atlas Copco has developed a compressor that allows the input energy required for operation to be reused in the form of heat in other systems.

Heat for heating or steam

Here is how it works: The heat generated, when the electric compressor is working, is cooled with a refrigerant like water. This cooling water passes through a heat exchanger that then can supply hot water to other systems.

Atlas Copco’s system is unique in terms of the high water temperatures that their compressors and heat exchangers can deliver: Normally around 90-95 ⁰ C.

Heat from compressors is generally used to heat buildings or to preheat process water. Heating demand is greatest in cold climates, like in northern Europe, which is why Swedish company Atlas Copco is a world leader in the field of heat recovery. In the rest of Europe there may not be as big a need for heating, but there is often a need for hot water or steam for various industrial processes.

Adam Airosto, President of the compressor section for Scandinavia at Atlas Copco, talks about these new water-cooled, oil-free and variable speed-drive compressors.

Airosto notes that it is difficult for industry to use recycled energy throughout the year as heating demands decrease over summer. Nevertheless, the first thing to think of is to put as little energy as possible into the compression process, and by controlling the speed, format and design, the required energy is minimized.

Traditionally, compressors use maximum delivery quantity. Using a speed controller controls how much compressed air is formed, so that production meets the need within the company. It also reduces noise, which affects the work environment positively.

The Swan eco-label

Thanks to their unique properties, Atlas Copco’s compressors are the first in the world to be certified for “zero net energy” by the German technical inspection authority TÜV. An independent international organization specialized in evaluating the safety and quality of technology, the TÜV certification proves that Atlas Copco’s compressors actually can recover all the input energy.

Atlas Copco can also boast to be the only company that received a “Swan”-marked air compressor. Eligibility for the label’s combination of features that makes the concept so unique include, speed ​​control, energy recovery and oil-free technology. The oil-free technology allows the compressed air and the condensed water to be completely oil-free, which in itself is an environmentally benefit and very important in certain types of industries such as food.

“The various certifications have been important because the environment and energy are major focus areas today, and will surely grow even bigger in the future,” says Airosto. “Sure it affects how others see us, but also how we see ourselves. Internally, we are proud of the work we do and the products we develop, and we don’t want to release any products on the market without knowing that they are the most efficient available. ”

According to Airosto, it is the customer’s responsibility to make sure the internal environmental work is up to par with the compressors, since 99% of the total environmental impact of a compressor’s lifecycle from product development to disposal comes from the user end.

The biggest environmental impact occurs when the compressor is used. “It is encouraging and gratifying to see that customers can see for themselves that what we are certified for is really true,” says Airosto.

This article was published in May 2011