Smaller and medium-sized cement facilities often employ vertical shaft kilns, also known as vertical kilns, to calcine clinker. The entire feeding, calcining, crushing, and discharging process can be automated.
Before the rotary kiln was conceived, vertical kilns were commonly employed in cement companies worldwide. The Vertical Shaft Kiln was the traditional kiln used to make cement until the rotary kiln came along in the 20th century. Many cement manufacturers in nations like India, however, are still using vertical kilns.
Structures and Operation of Shaft Kilns:
Vertical Shaft Kiln Suppliers in India provide disc pelletizers in vertical kiln cement plants that turn ground raw materials into wet pellets by adding 12-14% water to the pelletizing pan. After calcination, the wet pellets are released from the kiln's bottom.
The interior of the vertical kilns is segmented into three distinct zones, designated by their respective temperatures during operation: the preheating zone, the calcining zone, and the cooling zone.
The Preheating Zone
When wet pellets are placed in a kiln, the hot air circulating from the bottom to the top of the kiln causes the water inside the pellets to evaporate.
Simultaneously, the fuel's volatile components constantly evaporate as the temperature rises. Because the hot air flow contains no oxygen, the flammable material is not burned but released into the atmosphere together with the exhaust gas.
The ball of material continues to sink deeper into the vertical kilns as the kilns heat up due to gravity. Dehydration of the kaolin occurs between 500 and 600 °C, and the carbonate begins to disintegrate, and a portion of the solid-state reaction takes place at temperatures above 700 °C.
Only 5- 10% of the kiln's overall height is devoted to the actual body, where temperatures range from 20 to 1000 degrees Celsius.
The Calcining Zone
As the raw material enters the calcining zone, its temperature will continue to rise above 1000 °C.
Most of the coal in the raw material begins to burn at this point, causing a rapid rise in temperature and a multitude of solid-state reactions; the exothermic solid-state reaction causes the temperature to soar to well above 1300 °C, at which point the material enters a liquid phase and the sintering stage.
Coal in the raw material, coal quality, pellet size, air flow condition, pre-homogenization of the raw material, discharge speed, and operational level all influence the height and position of the calcining zone in the vertical kilns. The calcining zone is the area just below the kiln's expansion port, and it typically takes up only 10–15% of the kiln's overall height.
The Cooling Zone
In a Vertical Shaft Kiln, the calcined clinker moves through the cooling zone, it loses heat to the cold air being sucked up from below. After the clinker has been cooled, the air is heated and sent upwards into the calcining zone, which aids in the combustion process.
Leading Manufacturers of Shaft Kilns:
We at Kinc Group are a cement plant project contractor and equipment maker. Worldwide, our clients can count on us for turnkey solutions to their vertical kiln cement plant solutions. Due to the renowned goodwill in the market, Kinc Group is considered to be the best Vertical Shaft Kiln Exporters in India.
