© fotolia.com/martinseb, Gernot Walter

Air cleaner: Sucking it away

Air cleaners from ISI Industrieprodukte GmbH keep the air pure around machining centers.

The chips fly when modern machine tools are at work, and the cooling lubricants they use are a source of aerosols, oil mist and vapors that can endanger the health of the employees who work with them. To keep that from happening, machine tools have air filters that safely extract emissions and suspended particulate matter to protect the health of the people around them.

A leading manufacturer of such filter units is ISI Industrieprodukte GmbH from the town of Buchholz in the German state of Rhineland-Palatinate. The company has made a name for itself over the decades while steadily improving its products. Like the rest of the sector, in 2013 its management faced the challenge of designing its filter systems to conform with the newly introduced ErP Directive.

Improving instead of merely adjusting

The simplest approach seemed obvious enough, as Guido Vostell, sales manager at ISI Vertriebs GmbH, recalls: “At first we simply wanted to replace the existing AC blowers in our filters with more efficient blowers — like our competitors. But while searching for suitable products, we came across ebm-papst and realized that this forced modification was a big opportunity for us if we actively shaped it instead of just trying to do the minimum to satisfy the standard.” So ISI found out more about EC fans. They not only promised energy consumption considerably below the usual levels, but also offered other attractive advantages for ISI. “We noticed quickly that we could implement nearly all of the extra benefits offered by the EC fans from ebm-papst as benefits in our product,” says Vostell.

„We noticed quickly that we could implement nearly all of the extra benefits offered by the EC fans from ebm-papst as benefits in our product.”

Guido Vostell, sales manager at ISI Vertriebs GmbH

The first positive effect already showed in the redesign of the air filters. Since the newly installed EC fans are very compact, ISI was able to make the entire air filter smaller, saving space in the machines in which the final product is used. Another big benefit that the EC fans can realize in the air filters is their precise controllability through their entire speed range. Vostell explains how his customers benefit: “Especially big OEMs who install our air filters can now integrate fan control completely in their machine control systems. Then the air filter adjusts its air performance automatically to the step currently being performed by the machine. If more pollutants are being generated, it sucks harder; when the machine is not working so hard, fewer pollutants arise and the filter runs more slowly. That wouldn’t have worked so easily with AC fans.” This controllability also means a longer service life for the installed filters since they don’t have to work with maximum filter surface loading when it isn’t needed.

Energy costs cut in half

Since the aim of the new generation of air filters was compliance with stricter guidelines, the high efficiency of the fans naturally played the biggest role. On average, the energy costs for the air filters with EC fans are more than 50 percent lower than those of their predecessors. “For just one machine, that’s a difference of several hundred euros per year,” says Vostell. “When an entire building is full of machines, it really pays off.” The savings are so high because the power consumption is approximately proportional to the cube of the speed. That means that half the speed means only about an eighth of the power consumption. The energy savings become especially noticeable in partial-load operation since the efficiency of the EC motors remains at a high level.

A pleasant side effect of the high efficiency is that the fans bring little extra heat into the building and make work there more tolerable in the summer. During all seasons, the low noise emission of the EC fans is noticeable. And thanks to their smooth operation, they cause significantly fewer vibrations than conventional fans. That’s especially important for precision machines that need to work as free as possible from negative external effects.

Today ISI uses EC fans from ebm-papst in almost all of its air filter designs. “The details of the application don’t really matter; the EC products show their advantages everywhere,” says Vostell. “And we’re ready for the future with them because we still haven’t maximized the possibilities for increased efficiency offered by controllability combined with sensors. We see more potential there to make even better products for our customers.”

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