| 摘要 |
A method and apparatus (10) for delignifying comminuted cellulosic fibrous material (paper pulp) with ozone. Pulp having a consistency of about 25-45% is fluffed (in 16), ozone is added to it (17, 19), and then it is pneumatically conveyed (by 20) in a pathway (21) for at least several seconds (e.g. about four seconds). The majority of the gas is then separated from the pulp in a cyclone (22), and the pulp is discharged into a retention tube (25), where it is retained for at least a few seconds (e.g. about ten seconds) in a relatively static condition. It is then fed through an air lock (26) to another blower (120), and additional ozone added to it (via 35), then the above steps are repeated. The gas separated from one cyclone (123, 223) can be returned as conveying gas to another blower (20, 120). The method is practiced at a pH of about 1.8-3.5, and a temperature of about 20 to 50 DEG C. <IMAGE> |
