摘要 |
Apparatus for transferring particulate contact material by gravity from an upper contact zone wherein it is contacted by a first gas flowing radially, to a lower zone wherein it is contacted by a second gas flowing upwardly. The apparatus includes a generally annular transition zone which connects the upper and lower zones. The transition zone effectively isolates the second gas from contacting the particulate material in the upper zone. In a preferred embodiment in the form of a catalyst regenerator, catalyst particles can be sampled for carbon level in the transition zone to determine if the carbon burn-off therefrom is sufficiently complete in an upper radial flow regenerator bed by contact with a first gas, having a relatively low oxygen level. The sampling can be done on stream, even though a second gas, such as relatively oxygen-rich halogenation gas, is passing up through the catalyst in the lower zone.
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