subject: The Working Principle Of Hongxing Rotary Kiln [print this page] Henan Hongxing Mining Machinery Co., LtdHenan Hongxing Mining Machinery Co., Ltd. is a professional rotary kiln manufacturer with decades experience and advanced technology. This article will give a brief introduction about the working principle of lime kiln.
A preheater can be added to an existing kiln of any length. By retrofitting a preheater onto an existing kiln the system efficiency can be greatly improved. In some cases the preheater is added at the feed end of the existing kiln. In other cases the preheater is installed over the lime kiln, as the limestone kiln continues to operate. After the preheater is completely erected, the lime rotary kiln is shortened and a transfer chute is installed, connecting the preheater to the kiln. Downtime is reduced and operations are enhanced.
Stone feed size to a preheater of rotary kiln can range from 1/4 to 2-1/2 with the preferable ratio of top to bottom size of 2:1. In a modern, well designed preheater rotary kiln calcining system, fuel efficiency can be as low as 4 MBtu/Ton.
Limestone enters the calcining system by being fed into the stone bin by the stone conveying equipment. The stone exits the bin by gravity through the stone feed chutes and into the preheater. The internal geometry of the preheater holds the accumulated stone into a vertical bed until it is heated and ready for discharge. The hot rotary lime kiln exit gases are pulled from the kiln, through the bed of stone, before exiting the preheater through the exhaust gas duct. As the hot gases pass through the stone bed, sufficient heat is transferred from the gas to the stone to start the calcination reaction. This heat recovery is one of the key elements in producing high quality lime with reduced fuel consumption.
After heating and partial calcining in the preheater, the stone is discharged by having the bottom of the bed of stone pushed by a hydraulic ram to the preheater discharge opening. As the ram is retracted additional stone flows from the stone bid to replace the material that was discharged. The discharged stone flows by gravity through the transfer chute and into the limestone rotary kiln. The high temperatures in the rotary limestone kiln complete the calcining process.
