High intensity impeller wheel
High intensity impeller wheel
Keywords: Strahltechnik Illingen, Shot blasting, Abrasive wear, Steel
Because existing wheel shot-blasting units require frequent wheel changes due to internal wear, waste a good part of the abrasive working material and lack precise abrasive stream control, Strahltechnik Illingen (SI), a German steel processor, has developed and is producing a new, high intensity shot-blasting unit based on a novel, patented, dual-rotor centrifugal wheel (Plate 2).
The new "SI-Wheel" has been designed to reduce rotor vane wear to a minimum because the abrasive shot material no longer impinges strongly on the impeller blades as in conventional units. This feature reportedly also raises shot-blast energy, eliminates abrasive material degradation and allows more precise blasting stream direction and working area control.
The secret of the innovation is an auxiliary, second rotor inside the hub of the outer impeller turbine wheel. This rotor improves feed and direction of the abrasive particles by giving them a tangential impulse speed prior to their discharge into the main impeller turbine. This feature claims to eliminate direct, hard impact on the main impeller blades which in conventional units causes partial slowdown (energy loss) and some break-up of the abrasive pellets(abrasive material waste). Result: a forceful, unimpeded shot-blast flow without stray particle dust and increased stream direction control. It also permits an increase in the number of vanes on the main impeller, further increasing efficiency.
Plate 2 The patented SI-WHEEL
To illustrate this, take the case of a Swiss customer who fitted the new SI-Wheel shot-blasting units into his 80-meter long, steel finishing plant producing up to 100 tons sheet steel/day. Steel shot of 0.5-0.9mm dia. is employed. Maximum production speed in the two, 30-year old parallel lines in the old plant increased to 3m/rain, sheet width to 2.1m. That means: output has more than doubled!
In another example, a Czech subsidiary of a well-known German steel casting company cut shot-blasting times in half. Special advantage: with the new SI-Wheel all corners of the parts could be treated in the shortest possible time without touching and affecting the already precision finished edges.
Because of the more precise directional and area control only two SI-Wheel units are needed where three conventional shot-blasting wheels were previously installed. This, of course, reduces required investment and also power consumption.
In addition to the new SI-Wheel abrasive shot-blasting units, SI custom-designs and supplies complete, integrated metal finishing plants which can incorporate everything from metal degreasing, shot-peening, derusting and finishing equipment.
Because direct export from Germany is sometimes not practical or possible, SI will consider licensing its SI-Wheel units and technology to qualified overseas manufacturers under licence-, joint-venture- or other cooperation agreements.
Details are available from Strahltechnik Illingen GmbH. Tel: (+49) 7042 828 500; Fax: (+49) 7042 828 511; E-mail: strahitechnik@s-directnet.de
