Reliable Sludge Removal for Water Jet Cutting

Rotary lobe pumps convey even highly abrasive residual water without damage

A TORNADO® T2 rotary lobe pump ensures reliable desludging of waste water from waterjet cutting in industrial processes.

Despite the high abrasiveness of the residual water, the design of the pump ensures a particularly long service life.

Look behind the scenes

Cutting systems, which are based on high-pressure water jets and do not alter the material structure through their energy input like lasers do, are establishing themselves in more and more areas, such as robotics or automotive manufacturing. A cutting aid, an abrasive, is mixed into the water to increase cutting performance. This abrasive is frequently a fine garnet sand. After the cutting process, the water-sand mixture has to be separated again, so that the sand can be disposed of. A manufacturer of water jet cutting systems offers an automated solution for its systems to remove and separate the sludge from the water.  

Challenge accepted

Although the sand may be very useful as a cutting aid, it does lead to effort in terms of disposal. In order to relieve the burden on their customers in this area, the manufacturer offer an automatic removal system for their machines: The water-sand mixture is transported by pump to a cyclone which separates the solids from the water using centrifugal force and thus makes disposal easier. Because conventional pumps wear very quickly due to the abrasive medium, the company is using the particularly robust TORNADO® T2 rotary lobe pumps made by NETZSCH Pumpen & Systeme GmbH. Their condition is almost as good as new, even after double the operating time in comparison to the previous centrifugal pumps.  

Excellently solved

In order to find an efficient and cost-effective solution, the manufacturer has therefore been testing the robust TORNADO® T.envi® rotary lobe pump since the end of 2014. A characteristic feature of this type of pump is its combination of materials. Whereas other pump manufacturers normally have elastomer lobes rotating in a metal housing, steel rotary lobes are used here and the inside of the pump is lined with a rubber insert. For its tests, the water jet cutting expert used the T2, a version of the TORNADO® which has a pumping capacity of 35 m³/h. The final evaluation of the test pump was carried out after the device had circulated a total of 90 t of the sandy abrasive. It was not possible to detect any wear in the pump chamber on NETZSCH's T2, in spite of the long operating time. The insert and the mechanical seal were still in perfect condition. The shaft sealings, including contact pressure and lubrication, also showed no damage or impairments. Only the rotary lobes showed slight traces of wear at the tips. The clearances still conformed to the dimensions at the time of delivery. Overall, the loss of pumping capacity due to these signs of wear was so small that it was possible to compensate for this without any problem by slightly increasing the speed. The rotary lobe pump continued to be used effectively, despite already having double the service life. For even greater improvement of service lives, which were already good, NETZSCH experts have further optimised various aspects of their TORNADO® pumps for standard use in water jet cutting systems and tailored them to the specific application conditions. The customers can in future fully concentrate on the demanding cutting process, with the removal of residual water and sludge taking care of itself.

Get an individual offer for your application now!

TORNADO® T2 rotary lobe pump

  • Medium: Water-sand mixture
  • Pumping: 3 bar
  • Pumping capacity: 35 m³/h


You may also be interested in:

TORNADO® T.Envi® Rotary Lobe Pump

The TORNADO® T.Envi® rotary lobe pumps in FSIP® design are optimally adapted to your requirements in environmental and biogas technology and impress with easy maintenance.

TORNADO® T.Sano® All-Metal Rotary Lobe Pump

The TORNADO® rotary lobe pumps in all-metal version are primarily used in the chemical and food industry. These pumps are suitable for sensitive and aggressive media as well as media with high hygienic requirements. 

NEMO® SY Industrial Construction in Bearing Block Design

The NEMO® SY progressing cavity pump is used for demanding applications in every branch of industry around the globe. In bearing block design with free shaft extension, this pump can be run with any type of drive, such as servo motors, diesel motors or hydraulic drives.

NEMO® Progressing Cavity Pump in FSIP® Design

The FSIP® concept of the NEMO® progressing cavity pump is especially interesting where pumps are installed in wear intensive applications.