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For conveyors that operate at ambience temperature, we will pre-tense the belt and step by step increase the speed until reaching the working speed. We must observe that the belt remains straight, with no friction on the sides. We should never line up or place the belt by scraping along the edges. The lining up must be done by correcting the cylinders (driving, return, supports, etc.)
A high temperature belt must run in a way similar than any other precision part. The oven must increase its temperature at a speed not higher than 148° C per hour. Once the working temperature has been reached, the belt must work around 5 hours without charge, to ensure the correctly settling-in of the belt elements (spirals and cross bars). The temperature changes affect in the breaking properties of the belt material, requiring close attention to the belt adjustment during this period.
During the rolling period, we must eliminate any tension of the belt to ensure the maximum working life. We avoid an excess of grain growing by annealing at the adequate temperature resulting in an increased service life by removing any tension at the right temperature.
The process of avoiding the tensions may be resumed with two suggestions:
1- For alloys that work at 925° C or more, the treatment of tension elimination must be quite long, so that each portion of the belt works at 925° C at least during one hour.
2- For alloys that work at 898° C or less, the treatment of tension elimination must be done at 28° C over the normal temperature during a period of time enough so that each belt section arrives to the temperature of elimination at least during one hour.
At that moment, the belt must run a minimum of 5 hours without any charge. Generally, the high temperature belts have a quantity of tension predetermined before the tension mistake occurs. The intentional tension of the belt only enables some hours of maintenance at the expense of a big decrease of the belt lifetime.
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