Lorenz Hoffmann reaps energy benefits from new vacuum pump

LORENZ HOFFMANN uses high-precision CNC milling machines in its modern machinery fleet to produce prototypes, such as for machine building. To meet the highest precision requirements during milling, the workpieces must not slip by even a hundredth of a millimeter during the milling process. This is why they are fixed in place with the help of vacuum. To do this, employees use special vacuum clamping plates connected to vacuum pumps. 

Lower energy consumption, higher quality

The company had previously used one of its own vacuum pumps at each of its four CNC milling machines. MD Andreas Hoffmann wanted to optimise the vacuum supply in his operation, so he replaced the four oil-lubricated rotary vane vacuum pumps with a single COBRA PLUS dry screw vacuum pump from Busch Vacuum Solutions.

This is connected to the four milling machines via pipelines. "Purchasing the COBRA has saved us 3,500 kWh per year compared to the four oil-lubricated rotary vane vacuum pumps we previously used - and with even better holding power," said Hoffmann. This is because the COBRA PLUS is speed-controlled, so it adapts its power to the actual demand and therefore consumes less energy than an unregulated vacuum pump, whose motor always runs at full rotational speed.

"The COBRA regulates itself and always delivers exactly the power we need. For example, if only one milling machine is in use, the COBRA operates at a lower rotational speed than when several milling machines are running simultaneously," explained Hoffmann. 

Better working conditions, low maintenance

All COBRA screw vacuum pumps from Busch operate completely contact-free, which means they do not require any oil in the compression chamber. "Since switching to the COBRA, we no longer need to change oil, exhaust filters or any other filters. This saves around four working days of maintenance per year. So far, the COBRA has been running without any malfunctions, and no maintenance has been necessary at all," Hoffmann continued. 

Using waste heat for warm buildings

By switching to the COBRA, Lorenz Hoffmann had the opportunity to use the waste heat from the new vacuum pump for heating. "The COBRA is water cooled. The warmed cooling water passes through an air heater. This is how we heat our production hall," Hoffmann stated. This air heater contains a fan and a heating coil that cools down the water so that it can be used again in the COBRA.

As a result, the company needs significantly less heating oil than it would otherwise use. "In the summer, we direct the waste heat outside. In the winter, it remains in the manufacturing facility. As a result, it is now noticeably cooler in the production hall, even during the warm season. Previously, the production hall would always get quite hot in the summer," he added. 

For more information:

www.buschvacuum.com

Tel: +44 (0)1952 67 74 32