Indirect Heating Rotary Calciner Rotary Kiln

Product Description

The 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. The treated material is discharged from the lower end by the inclination of the cylinder.

Working Principle of rotary calciner
The material enters the furnace 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.  
Characteristics of 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 rotary calciner
Rotary kiln can be divided into cement kiln, metallurgical chemical kiln and lime kiln according to different processing materials. It 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.
Specification of rotary calciner

Specification	Length(m)	Speed(r/min)	Slope(%)
ZT800	6~12	0.5~3	1~5
ZT1000	8~15
ZT1200	8~18
ZT1400	10~20
ZT1600	12~22
ZT1800	14~24
ZT2000	12~26

Now rotary calciner is 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.

In the process of heat treatment, i.e. roasting, the rotary cylinder has a small inclination. Bulk solids move continuously from the feed end to the discharge end in the kiln, which saves more energy.
There are two model of the rotary calciner, direct heating rotary calciner and indirect heating calciner.

In indirectly heated rotary kiln, the rotary cylinder is heated from outside. This can be achieved by burner or electric heating. Especially when the treated product is prone to produce strong dust, it must undergo different temperature gradient requirements or must be treated under special process conditions, such as inert or protective atmosphere.