1. Working Principle
The rotary drum dryer consists of a slightly inclined cylindrical main body with adjustable rotating speed within a certain range. Wet material is fed into the cylinder by a feeder and dispersed during feeding. Cold air passes through an air filter and is blown in by a blower, heated by a steam heater and then delivered into the cylinder. With the turning of lifting plates evenly arranged inside the drum, materials are uniformly spread and dispersed to fully contact hot air, accelerating heat and mass transfer to realize drying. Most dried materials are discharged from the kiln tail box. Exhaust gas is dedusted by a cyclone dust collector and water scrubber before discharge. Hot air flows co-currently with materials. Various types of lifting plates are available to suit different materials. It features simple structure, reliable operation, easy maintenance and large production capacity.
2. Unit Features
1. The kiln head is equipped with scrapers and a fixed cylinder with extended spiral lifting plates welded on the kiln head as a stationary barrel. Scrapers welded on the rotary drum serve as moving blades. The extended spiral lifting plates are extensions of the rear spiral guide lifting plates. Most materials are conveyed away by the extended spiral lifting plates. The scraper removes materials adhered in the gap between lifting plates and the stationary barrel, then the extended spiral plates transport them out to ensure smooth material feeding.
2. Continuous and quantitative feeding is equipped at the drum end.
3. Sludge is pre-dispersed and crushed upon feeding for sufficient heat exchange with hot air and fast drying.
4. The drum is installed at an inclined angle to achieve thorough discharge without dead zones.
5. Discharged exhaust gas enters cyclone collectors, then goes through a washing tower for cleaning and cooling before release (deodorization system can be added separately).
6. The machine supports large-scale continuous production and can utilize waste flue gas for drying.
Applications
● Suitable for drying large-particle and high-specific-gravity materials in chemical, mining, metallurgical industries, such as ores, blast furnace slag, coal, metal powder, phosphate fertilizer, ammonium sulfate, sludge and coal slime.
● Suitable for drying powder and granular materials with special requirements, e.g., GP foaming agent, distiller’s grains, light calcium carbonate, activated clay, magnetic powder, graphite and medicinal residues.
● For materials requiring cooling and large-volume continuous processing.
● High-temperature calcination requirements shall be specified during order placement.
● Cyclone, baghouse or water scrubber dedusting can be selected according to carbon content in exhaust gas.
● Heat sources: electricity, steam, heat pipe, hot blast stove or waste heat.
Overview
The rotary drum sludge dryer adopts a slightly inclined cylinder with adjustable rotating speed. Wet materials are fed into the cylinder. Materials are turned by evenly distributed internal lifting plates, fully contacting hot air (co-current or counter-current) passing through the drum to accelerate heat and mass transfer for drying. Multiple lifting plate types are optional for different materials. It has simple structure, reliable operation, convenient maintenance and high throughput.
