A roll crusher is a compression-type crusher used for crushing soft to medium hard materials. It has a major role in the mining industry, and it is used in the industrial processes as well. The roll crusher has a simple structure, consisting a cast-iron frame and two or four cylinders, sitting on a horizontal axis. Although the roll crusher is not as productive as the cone or jaw crusher in terms of total production capacity, the roll crusher still brings few unique advantages. One big advantage is that it gives an accurate product size distribution and if the material that needs to be crushed is not too raw, the maintenance costs are very low, which is not a case with a cone or jaw crusher.
The working principle of the roll crusher is very simple. A material gets between the two cylinders and is being crushed by a compressive force generated from the two cylinders, which roll in opposite directions. The roll crusher crushes the material until it gets small enough to freely move through the opening between the two cylinders. The size of the opening can be adjusted depending on the size that needs to be achieved. It is stated that the maximum reduction ratio of the roll crusher with two cylinders is 4:1. For example, if a 5-cm particle is fed into the roll crusher, the smallest size that can be expected is 1.3 cm.
The roll crusher is very suitable for mineral applications, as the minerals are not very abrasive and are most commonly needed in smaller sizes. The roll crusher has a major role in the coal plants as well. With teeth or raised forms on the face, the roll crusher is very efficient tool that can be used in every coal plant. Furthermore, the roll crusher has a big role in many other applications, such as concrete recycling, metal production and etc.
A four-cylinder roll crusher is very similar to the double roll crusher, with the main difference that it uses four cylinders to crush the materials. The first pair of cylinders is positioned just above the second pair of cylinders. The second pair crushes the materials in order to give the final product a better finish. However, both roll crusher types have a simple structure, and have low maintenance costs.
