| 摘要 |
<p>Oxygen bleaching of high consistency pulp takes place in an oxygen reactor. Pulp is mixed with oxygen, and emulsified in a defibrator, and then is transported under pressure to the bottom inlet of an oxygen reactor. The pulp moves upwardly in an inner, concentric sub-vessel of the oxygen reactor and caustic may be inserted into the pulp while moving upwardly in the inner sub-vessel. At the top of the sub-vessel the pulp is dispensed by a scraper, which prevents channeling, over the edge of the sub-vessel and into the outer chamber surrounding the inner sub-vessel. A top portion of the outer chamber, above the sub-vessel, contains pressurized gas, and the concentration of explosive gases in the top portion is sensed, and the gases are exhausted from the top portion and replaced by compressed air (or a similar non-explosive relatively inexpensive gas) when the concentration of explosive gases exceeds a predetermined amount.</p> |
