| 摘要 |
<p>Material is heated by hot counter-current gas and is subsequently cooled. This is effected by known equipment comprising direct heat exchangers formed by cyclones or turbulence chambers mounted one above the other and connected by channels for gas and material. The material passes downwards and the gas upwards. Also at least one heat exchanger at the bottom is connected to a cold air duct; a heat-exchanger mounted higher up is connected to a hot gas inlet duct.</p> |
