Method and apparatus for mixing gases with a wood pulp slurry

Abstract

Process and apparatus for mixing a wood pulp slurry with a chemical at the consistency at which the slurry exits a washer or the subsequent steam mixer, 7 to 15%. The chemicals would include noncondensable or unsaturated gases such as oxygen, ozone, air, chlorine, chlorine dioxide, sulfur dioxide, ammonia, nitrogen, carbon dioxide, hydrogen chloride, nitric oxide or nitrogen peroxide. Highly superheated steam can also be mixed with the pulp. In the process, the pulp slurry would pass through a mixing zone having a swept area in the range of 10,000 to 1,000,000 square meters per metric ton of oven-dry pulp. The preferred range is 25,000 to 150,000 square meters per metric ton of oven-dry pulp and the optimum is considered to be around 65,400 square meters per metric ton of oven-dry pulp. The pulp slurry passes through an annular mixing zone. Specific designs of the various elements of the mixer are disclosed.

Dependencies are inferred from the claim text.