Cement Mill
Description:
The triple-drum rotary dryer is an upgraded piece of equipment based on the traditional single-cylinder long-drum rotary dryer. The internal structure of the triple-pass sand dryer includes an inner cylinder, a middle cylinder and an outer cylinder; at the same time, each layer of the triple-pass sand dryer is fitted with lifting plates at different angles and different spacings. Compared with a single-cylinder dryer, the triple-cylinder dryer shortens the body length and saves floor space. It also performs sealing, moisture-retention and other treatments, which further raises the thermal efficiency of the sand dryer and ensures high efficiency and energy economy.
Structure:
The triple-drum (triple-pass) dryer is an improved design of the single-drum dryer, in which one drum is replaced by three drums nested one inside another, allowing the overall dimensions of the equipment to be significantly reduced.
During operation the material and the hot air flow pass successively through the inner, middle and outer drums. After repeated Z-shaped movement inside the dryer, the material fully utilises the thermal energy, is dried effectively and is then discharged.
The drum part of the dryer consists of three coaxially arranged horizontal drums — inner, middle and outer — nested one inside another. This design ensures the most efficient use of the drum cross-section. The overall body length is approximately 30–35% of the length of a traditional single-drum dryer of comparable capacity, which significantly reduces the occupied area and the size of the production building.
The support system of the equipment uses a riding ring and support rollers mounted on the outer drum. The drive is provided by an electric motor that directly rotates the support rollers. Through the friction between the rollers and the riding ring, the drum is set in rotation.
The overall construction of the equipment is compact, rational and simple. For ease of maintenance and replacement of wear parts, the middle part of the body is made as a longitudinal split joint with bolted fixing.
Working Principle:
The material enters the inner layer of the rotating drum from the feeding device for subsequent drying. The material is continuously picked up and scattered by the lifting plate in the inner layer to achieve the purpose of heat exchange. The material moves to the other end of the inner layer and enters the middle layer for counter-current drying. The material is repeatedly lifted in the middle layer and moves two steps forward and one step back. The material in the middle layer not only fully absorbs the heat radiated by the inner roller, but also absorbs the heat of the middle roller, achieving the goal of saving energy consumption and prolonging the drying time. Here the material reaches its best drying state. The material moves to the other end of the middle layer and falls into the outer layer. The material moves along a rectangular multi-loop pattern in the outer drum. The material that has reached the drying effect moves quickly and is discharged from the drum under the action of the hot air. Wet material that has not reached the drying effect cannot be discharged quickly because of its own weight. During movement the materials are fully dried on this rectangular lifting plate, thereby achieving the final purpose of drying.
Equipment Advantages:
- 1. High thermal efficiency — the three-layer drum design provides a thermal efficiency coefficient of more than 80%.
- 2. Compact dimensions — the overall length of the equipment is 30–40% less compared with a traditional single-drum dryer.
- 3. Energy saving — low fuel consumption reduces operating costs.
- 4. Stable drying effect — uniform moisture of the finished material, suitable for continuous production.
- 5. Ease of installation and maintenance — the compact construction facilitates transport, installation and maintenance.
- 6. Wide adaptability — the internal design of the lifting flights and the operating parameters can be adjusted according to the type of material.
Applicable Materials:
The equipment is suitable for drying:
- Yellow sand
- River sand
- Quartz sand
- Mineral powder
- Fly ash
- Slag
- Coal slurry
- Biofuel pellets
- Sawdust and other bulk materials.
