Came into existence in the year 1968, we are famous as one of the fastest growing manufacturers and exporters of best quality Kiln Shells. It is a rotating inclined cylinder shape furnace, fired from one end to generate heat. Widely used during the production process of metals, construction materials, sponge iron, chemicals, cement, refractories, petroleum and gypsum, these Kiln Shells used various types of fuels for heating purpose.
A rotary Kiln is a type of inclined cylindrical shaped rotating furnace which is used to heat solids to a temperature level when a chemical reaction is triggered through a wet or dry process. These kilns have a huge demand in the production of petroleum coke, refractories, sponge iron, alumina, gypsum, construction materials, chemicals, cement, metals, etc.
The working principal of rotary kiln involves the firing of an inclined cylinder to generate heat from one end to all over its path. These Kilns generally fired directly and covered with refractory material to safeguard the steel shell to minimize loss by radiation and convey heat to the material.
All types of kilns are excellent heat exchangers that transfer heat through various modes like conduction, radiation and convection.
Different types of fuels which are used to ignite the kiln are petroleum coke, ground coal, gasses, fuel oils, and many more. Selection of fuel mostly depends upon the economics behind the consumption of a particular fuel. Transferring heat through gas radiation is an effective way to convey comparatively smaller amount of heat. Conduction to the charge and radiation from hot flame are reliable for hot bricks transfer.
Inclination of the kiln makes the processed material to move towards discharge point with every rotation taken by the entire body. From entry to discharge the form of material completely changes.
General Design Features:
A basic Rotary Kiln is a shell of cylindrical shape, with inclination from the horizontal and support on two or more riding rings also known as tyre stations. These are the base on which the supporting rollers rest. One among the tyres is mounted axially with the help of a set of thrust rollers to resit the load of of thrust during the movement of kiln and hence preventing the kiln from getting shifted from its axis. A pinion arrangement and girth gear assist in the rotation of the drum assembly. Prime movers in the rotary kilns are the gear reducers which are used to reduce or increase speed and torque as per the requirements. The designing of gear reducers can be done according to the needs of varied applications. On the gear support base the girth gear is mounted away from the shell end to protect it from encountering high temperature. The thermal expansion is compensated by the mounting of girth gear on the tangential spring plates fixed to the shells. Also, the driving pinion is affixed on the shaft that produces the output in helical gears/ worm.
Each moving piece of the equipment has frictionless bearings. These bearings are exclusively designed as per the application. Anti-friction bearings, also known as roller bearings, are the most common bearing. They give outstanding performance in any working condition. But, roller bearings are not suitable applications involving heavy loads. For this purpose, different types of bearing are utilized.
The length and the shell diameter of bearings are specifically designed to suit unique products and different capacities of production. Proper selection of length, speed, diameter, slope, and the interior design plays major role in setting the solid retention time of the kiln.
To prevent environmental air from entering, seal is necessary at each end of kiln. Any accidental air leakage can have different effect on the entire process. In some cases, it minimizes the efficiency and in others it can generate very unstable and unsafe conditions. The temperature and volume of the flowing gases are properly maintained by preventing the leakage of cold air inside kiln, especially on the area where the rotating shell enters the discharge and feed hoods. For this, reliable seal rings are fitted. There are different types of seal rings utilized for preventing leakage. The spring load type are the rings in which the finished metal surfaces are in contact with the support of spring. Continuous replacement and adjustments are required for sealing segments.
Due to the abrasive material and high temperature, wear resistant lining or refractory is required in a rotary kiln. This solid box refractory is installed in assorted areas very securely in a circumferential formation. With different compositions, the bricks have various types of properties like resistance to wear, maximum temperature bearing capacity and insulation value. Application where the use of bricks is not suitable, castables or liquid refractors are utilized with the support of anchors. Optionally, kilns have specific insulation material under the brick to get an extra layer to aid in the reduction of shell losses.
One of the most essential and integral components of a rotary kiln is its burner system. It is used to optimize the fuel combustion for the purpose of heat release in the kiln. Some of the parameters which a kiln operator must consider in the selection of furnace are flexibility & ease of operation, safety considerations, energy efficiency, environmental impact, product quality, maintenance costs, etc.
The working principal of rotary kiln includes direct heat injection at the end of the furnace. System fitted for the firing of different types of combustion fuels could be of any size and design. Burner is fitted on the area where the fuel is lighted. Mixing of air with the fuel could be done before or inside the burner. Temperature of the fuel is dependent upon the fuel/ air ratio, fuel type and other conditions of burning.
Dust Collection Arrangement:
Fumes of oil fired furnace contain definite proportion of minute dust which boards the air steam during contact with the heated materials. A high efficiency dust cyclone is utilized as a measure for pollution control. No matter how efficient these dry collectors are, they are not able to completely collect the dust. For this, wet collectors are used in the form of bag filter or sludge.
|rake of Kiln(%)||3.5||3.5||3.5||4||4||4||4||4||4|
|Number of bearings||3||3||3||3||3||3||3||3||3|
|Primary Power Rating (kw)||55||100||160||160||220||315||400||630||710|
|Reduction Ratio |
(For Gear Reducer)