| 摘要 |
<p>1483666 Preheating feed material ALUMINIUM PECHINEY 1 Aug 1974 [6 Aug 1973] 33923/74 Headings F4B and F4S A powder, for example alumina, is indirectly heated by gas, for example issuing from a rotary kiln 1, in a heat exchanger compartment 6, thereby generating gas which fluidizes the powder, the powder falling from an upper fluidization chamber 24 under the action of gravity in a substantially vertical tube 22, which may be disposed within the compartment 6, Fig. 2 (not shown), into a lower fluidization chamber 25 from which the powder passes upwardly under the action of the generated gas in a series of tubes 23, each of smaller diameter than the tube 22, to the upper chamber 24, the powder then partly leaving the chamber 24 and the remainder circulating within the compartment. As shown in Fig. 1 the gas from the kiln 1 passes through the compartment 6 into an electrostatic filter 13, purified gas being discharged into the atmosphere through a chimney 14. The powder is fed into the chamber 6 by means of a feeder 12, the heated powder leaving the chamber at outlet 11 to be fed into the kiln 1 for discharge at 5. The compartment 6 may house a series of stages of the pipes 22 and 23, Fig. 2 (not shown).</p> |
