The fly ash dryer is designed for fly ash, which has a higher initial moisture content and lower specific gravity than other materials, and exhibits significant fluidity fluctuations during drying. It features a compact structure and a small footprint, requiring only half the space of a single-drum dryer with the same output. It operates reliably, consumes low energy, has high thermal efficiency, and delivers excellent drying results. It is easily automated and requires minimal operator intervention.

Operating Principle

Wet fly ash is fed into the inner drum of a three-drum drum through a feeding device for downstream drying. Fly ash is continuously scooped and scattered beneath the lifting plates of the inner drum, creating a spiral motion for heat exchange. The material then moves to the other end of the inner drum and enters the middle drum for countercurrent drying. The material is repeatedly lifted in this drum, taking two steps forward and one step back. This middle drum absorbs heat from both the inner drum and the middle drum, extending the drying time and ultimately achieving a dry state. The material reaches the other end of the middle drum and falls into the outer drum. Inside the outer drum, the material travels in a rectangular, multi-circuit pattern. Dry material is quickly discharged from the drum under the action of hot air. Wet material that is not fully dried is held back by its own weight and fully dried within the rectangular lifter, achieving optimal drying and completing the drying process.

Technical Advantages

1. Highly technologically advanced, the drum itself insulates itself, achieving a thermal efficiency of up to 75% (compared to a single-drum dryer with a thermal efficiency of only 35%). This saves 68% of coal compared to single-drum dryers and increases production.

2. The overall length is 50% shorter than a single-drum dryer, facilitating process layout. This reduces plant floor space and saves approximately 40% of project investment. The floor space is approximately 40 square meters.

3. Made of heat-resistant and wear-resistant alloy steel plates, it is four times more wear-resistant than ordinary steel plates, resulting in a long service life and easy maintenance.

4. High thermal efficiency, with an outer drum temperature below 60°C (single-drum dryer outer drum temperature up to 150°C), low outlet temperature, and a discharge temperature below 80°C.

5. The low outlet temperature ensures long service life of the dust removal equipment and can be directly used with an air box pulse bag dust collector.

6. Construction investment is reduced by approximately 50%, and power consumption is reduced by 60%.

7. No large or small gears are required for rotation; instead, support rollers are used for rotation.

8. The hot air furnace can be used with fluidized bed furnaces, coal injection furnaces, hand-fired furnaces, and oil and gas furnaces. It can dry lumps, pellets, and powdered materials under 20 mm in size.

Fly ash dryer technical parameters