Compliance with the required material size is a decisive factor for ensuring efficient processes in opencast mining operations. With the Vario Impact Sizer (VIS) from Wirtgen, the new system offers flexibility, precision, and adaptability; it allows machine operators to reliably control the maximum particle size and particle size distribution, even under constantly changing operating conditions. 

Customizable settings create desired material sizes 

The core component of the VIS is a split baffle plate mounted directly on the cutting drum housing. This plate is equipped with two primary adjustment mechanisms that enable precise control of the material that passes through the system. The variable gap between the plate and the cutting drum is the first adjustment mechanism — this distance can be adjusted in five stages to control the amount of additional crushing and thus change the particle size. A smaller gap results in extra crushing and therefore, finer material, while a larger gap results in coarser material.

The adjustment is made by simply enlarging or reducing the gap and securing the plate with pins, which takes around ten minutes. The second adjustment mechanism relates to the holes in the scraper. Depending on the specific requirements of the operation, they can be opened or closed in four different settings by means of covers. These two mechanisms complement the basic adjustment options of the surface miner, like the advance speed of the machine, the speed of the cutting drum, and the cutting depth. In combination with the VIS, this results in an extremely high level of control over the maximum particle size.

The Vario Impact Sizer resolves common problems in particle sizing 

Machines in cut-to-ground or windrow applications often produce material that exceeds the required maximum particle size. This is where the VIS comes in — the system is designed to fulfill precisely this requirement by influencing and limiting the maximum particle size. Finer material passes through the sizer and leaves the crushing process, while coarser material is crushed until it can also pass the sizer.

The VIS is useful in both coal and bauxite mining applications and effectively controls the size of the material produced to meet the specified requirements. One of the advantages of the VIS is its seamless integration into the machine. The VIS is mounted directly on the cutting drum housing and integrates seamlessly into the material processing process. As well, the system is highly adaptable. The variable settings enable reliable crushing of a wide range of rocks and minerals. The VIS is particularly suitable for brittle and porous rocks and minerals such as coal, bauxite, or chalk. The robust construction of the VIS ensures that it can withstand the harsh conditions in mining and meets all requirements for durability and stability, even at high throughput rates.