Vol. 23
November Issue
Year 2022


in Vol. 23 - November Issue - Year 2022
Compact Continuous Feed Shot Blast Machine For Small, Delicate Castings

A cast work piece leaving the exit section of the new THM

The compact troughed-belt continuous shot-blast system THM 300/1 combines the small footprint of batch machines with the advantages of continuous feed operation

The THM troughed-belt continuous shot-blast machines from Walther Trowal are equally usable for mass-produced bulk parts as well as for delicate individual components with complex shapes

At the ANKIROS 2022 exhibition, Walther Trowal presents the compact troughed-belt continuous shot-blast system THM 300/1. This machine was especially developed for processing high volumes of small, delicate workpieces. The new design combines the small footprint of batch machines with the advantages of continuous feed operation, thus helping streamline and speed up the blast cleaning processes for small castings.

Walther Trowal developed the THM 300/1 specifically for small, delicate or thin-walled cast work pieces like, for example, aluminium or zinc die-castings with diagonal dimensions of between 20 and 150 mm (about 0.8 to 6.0”). Work pieces can range from components for toys (model cars and trains), furniture parts, components for the computer industry, and even small automotive parts. 
For the first time, a shot blast machine for processing small workpieces is available with the footprint of a batch tumble-belt machine that permits  continuous feed operation. Compared to the smallest THM machines supplied to date by Walther Trowal, the THM 300/1 design is considerably more compact requiring an area of only 1,4 × 2,7 m (5 x 9 feet) and can, therefore, be easily integrated into existing production lines. 
With this new machine concept, Walther Trowal meets the demands of customers in the foundry industry wishing to integrate their blast cleaning operations seamlessly into already existing manufacturing lines. 
The troughed-belt workpiece transport system Walther Trowal is utilizing for its continuous shot blast machines gently moves the workpieces through the machine in a spiral motion. This ensures that all workpiece surface areas are equally exposed to the blast media stream. 
Meik Seidler, sales manager at Walther Trowal, recognizes a significant trend towards continuous shot blasting: “The THM continuous feed machines with their unique troughed-belt workpiece transport system are increasingly displacing conventional batch tumble-belt machines. Our customers integrate the THM systems into linked manufacturing processes, allowing them to significantly simplify the workpiece handling. Optionally – and with an upgrade of the PLC – Trowal also offers industry 4.0 technologies. The workpieces are continuously fed into the machine at pre-set cycle times determined by the actual production volume. Intermediate transport operations from one process stage to the next, as well as intermediate storage, are completely eliminated.” 
For the new blast system, Walther Trowal is using the newly developed WTY turbines with curved throwing blades. Compared to conventional blast turbines, they generate a substantially higher throwing speed. This increases the impact energy of the blast media on the workpieces, which in turn helps reduce the processing times. 
A communication processor allows integrating the shot-blasting operation into higher-level process controls. Explosion-protected dust collectors ensure safe operation in line with prevailing explosion prevention standards.

For Information: 
Walther Trowal GmbH & Co. KG
Georg Harnau
Rheinische Str. 35-37
42781 Haan, Germany
Tel. +49.2129.571-209
Fax +49.2129.571-225
E-mail: g.harnau@walther-trowal.de