The sand dryer, also known as the rotary dryer, is a drier that can handle large amounts of material. Due to its reliable operation, large operating flexibility, strong adaptability, and high processing capacity, it is widely used in construction materials, metallurgy, food, chemical industry, coal, pharmaceuticals, and mining industries. The rotary dryer generally applies to granular materials but can also be used to dry sticky paste-like materials or materials with high water content by partially mixing them. It is especially effective for drying sand in slag powder grinding production lines.
Advantages of the rotary dryer include large production capacity, wide application range, low flow resistance, a wide allowable fluctuation range during operation, and convenient operation. It is commonly used for drying sand, mineral powder, cinder, etc., and works well with coal mills and sand dryers.
Structure and Principle of Sand Dryer:
1. Structural Diagram: The main components of the sand dryer are:
1) Cylinder; 2) Front roller ring; 3) Rear roller ring; 4) Gear; 5) Thrust roller; 6) Support roller; 7) Pinion; 8) Discharge section; 9) Lifting plate; 10) Reducer; 11) Motor; 12) Hot air duct; 13) Feeding chute; 14) Furnace body. Additionally, based on user requirements, gasifier furnaces, combustion chambers, or auxiliary equipment such as bucket elevators, belt conveyors, quantitative feeders, cyclone dust collectors, and induced draft fans can be designed.
Working Principle of Sand Dryer:
Sand is delivered to the hopper by a belt conveyor or bucket elevator, then enters the feeding end through the hopper's feeder and feeding pipe. The slope of the feeding pipe should be greater than the natural angle of repose of the material to ensure smooth flow into the dryer. The cylindrical drum of the dryer is slightly inclined to the horizontal line and rotates. Material is fed from the higher end, while the heat carrier enters from the lower end, contacting the material in a counter-current manner. There are also cases where the heat carrier and material enter the cylinder together in co-current contact. As the cylinder rotates, the material moves under the action of gravity towards the lower end. During the forward movement inside the cylinder, the wet material directly or indirectly receives heat from the heat carrier, allowing the wet material to dry. It is then discharged at the outlet end via a belt conveyor or screw conveyor. Inside the cylinder wall, there are lifting plates which serve to lift and drop the material, increasing the contact surface between the material and airflow, thereby enhancing the drying rate and promoting the forward movement of the material. Heat carriers usually consist of hot air, flue gas, etc. After passing through the dryer, the heat carrier generally requires a cyclone dust collector to capture the material carried within the gas. If further reduction of tail gas dust content is needed, it should pass through a bag dust collector or wet dust collector before emission.