| 摘要 |
This invention relates to a rotary kiln for the production of a granular bloated clay product, the kiln comprising a drying-kiln section and a burning-kiln section. In the heating zone in which the temperature of the clay granules increases from 300 DEG -400 DEG C to 800 DEG -900 DEG C the kiln is provided with a centrally located gas-flow tube which serves to protect the granules from the oxygen in the flue gas in the heating zone so that the bloating will be very effective. When passing the heating zone the granules pass the annular cavity between the outer surface of the gas-flow tube and the inner surface of the kiln lining. The outer surface of the gas-flow tube is provided with blades extending along the tube so that improved heat transfer from tube to granules is obtained. |
