Polyurethane tires are used on rotary screen plant

Polyurethane tires are used on rotary screen plant. Rotary screen plant is used extensively in the washing and grading of gravel and sand and also for heat drying of road stones. Other user include the preparation of natural and artificial fertilizers. Where the drum loading and temperature are such that the natural rubber can be used the substitution of polyurethane gives the expected advantages of higher load capacity and longer life. In many case however steel rollers have been in the past used in place of natural rubber due to the high loading required. In these case because of the highly abrasive environment, severe wear can take place both on the steel roller and the steel track on the drum itself. This wear leads to increased vibration in the plant which in turn can result in fractures of welds and rivets. To avoid serious damage the drum tracks have to be remachined at intervals during which the plant is inoperable. More recently these steel rollers have been successfully replaced by polyurethane tires in a number of cases. Taking a typical plant, for example, having an output of 50 to 60 tons per hour of washed gravel the weekly output is equivalent in value to ten times the cost of a set of polyurethane tires to replace the steel tires. The use of polyurethane tires reduces the vibration considerably and substantially reduces the maintenance time required. It also considerably reduces the noise level. In certain case the rotation of the drum can be carried out using polyurethane tires, with a further reduction in vibration.