Indirect heating rotary kiln

What is a indirect heating rotary kiln for sale?

Indirect heating rotary kiln is a kind of external heating rotary calcining kiln which is suitable for calcining and roasting various materials. Rotary cylinder of the rotary kiln is welded by heat resistant alloy texture furnace tube. It holds good working performance for calcining various materials and require 300 to 1250℃ calcining temperature. Typical materials are welding materials, catalyst and inorganic powder and etc.

The indirect heating rotary calciner(rotary kiln) is modified on the basis of conventional rotary cylinder dryer by changing the form of its heat source. An arched heating device (stacked kiln body) is added outside the middle section of the cylinder of the traditional rotary cylinder dryer, and the cylinder is heated by a plurality of burners distributed around the circumference of the kiln by burning a heat source such as natural gas, LPG gas, diesel, petrol, electric etc. The treated material is discharged from the lower end by the inclination of the cylinder.

Why need use indirect-heat rotary kilns/ dryers？

For various reasons, some products dried or calcined in a rotary kiln/dryer require special conditions that cannot be met by a direct-heat rotary kiln/dryer. For example, more control of the atmosphere within the dryer to promote oxidation or reduction may be required. The material may be extremely fine or need to be handled more gently. For other processes like drying food, preventing contamination of the product is important. Each of these issues can be addressed by the use of an indirect-fired rotary drum kiln/dryer. For this type of rotary kiln, the heat for drying/calcination is applied to the shell of the cylinder. This may be accomplished by steam jacketing, oil heating, or furnace encasement of the rotary drum.

An indirect-fired rotary kiln/dryer also has specialized flights within the drum. These flights are included to provide enough agitation of the material to promote efficient heat transfer. Because the shell itself is heated, the gas velocities within the drum are lower and the size of the gas handling system is smaller.

Working Principle of indirect heating rotary calciner

The material enters the rotary kiln  through the kiln head feeder, and an arc-shaped heating device (stacked kiln body) is added outside the middle portion of the cylinder. The furnace is equipped with a fuel burner or an electric heating element, and the flame of the burner or current of the electric heating element is adjusted by an automatic control system to control the temperature of the furnace so that the material is calcined at a certain temperature, and the calcination time can be controlled by adjusting the rotation speed of the furnace. The treated material is discharged from the lower end by the inclination of the cylinder.  

Typical structure of the indirect heating rotary kiln is following.

Characteristics of indirect heating rotary calciner

1.The equipment has compact structure and good sealing effect, which reduces material loss and heat loss.

2. Automatic temperature control, segmentation setting, over-temperature alarm, long kiln lining life, uniform wall temperature distribution in each zone, temperature control accuracy ≤± 5 °C.

3.The gas combustion is sufficient, the heat transfer efficiency is high, the heat preservation performance is good, and the surface temperature rise of the equipment does not exceed 50 °C.

4.The thermal efficiency of the burner is >99%, the single-pass thermal efficiency of the roaster is more than 41%, the flame of the burner is columnar or flat, straight and powerful.

5. The combustion system exhaust NOX concentration is not higher than 100mg/Nm3.

Applicable Materials of indirect heating rotary kiln

The indirect heating Rotary kiln has been successfully applied to the roasting of molecular sieve catalysts and catalytic cracking catalysts, oil sands, fly ash, alumina, chrome ore, chrome ore powder, cement clinker, activated lime and light burnt dolomite. Now rotary calciner is also widely used in the roasting of special materials such as special catalysts, special molecular sieves, kaolin, mineral powder, special adsorbents, inorganic salts, etc. in petrochemical, inorganic chemical, metallurgical and construction industries. Examples of main applications are refining catalysts, zeolite molecular sieves, activated carbon adsorbents, magnetic materials, sulfide ores, manganese ores, soda, aluminium hydroxide, refractories, silicates, ceramics and other materials.

Indirect heating rotary kiln manufacturer

Sinonine selects high-quality raw materials and accessories, adopts advanced processing technology, and ensures the indirect heating rotary kiln has high quality. From design, raw material selection, manufacturing, debugging, every step is meticulously carried out to complete excellent drying operations.

Indirect heating rotary kiln goods Delivery

Based on good quality and decades of experience, the Indirect heating rotary kiln which is manufactured by Sinonine was exported to different countries. The Indirect heating rotary kiln will be packed and loaded in our factory, and then be shipped to our clients safe and sound.

Specification of indirect heating rotary kiln