Appeal No. 1998-1832
Application No. 08/434,331
regenerated soda from the black liquor combustion 13 in oxy-liquor.” See column 6,
lines 7-11. Accordingly, we conclude that there is no suggestion or teaching in
Mannbro of using two separate recovery systems.
We find that Reeve is directed to feeding all the liquid effluent of the bleach plant
directly or indirectly to the pulp mill spent pulping liquor recovery and regeneration
operation. See column 2, lines 8-10. We find that Figure 1 discloses that the bulk of
the caustic extraction filtrate in line 102 is used to dilute the concentrated white liquor
in line 56 to provide the recycled pulping liquor in line 14. See column 6, lines 39-42.
Ultimately however, after digestion, it becomes black liquor 14. Further reference to
Figure 1 discloses that Reeve contains only a single recovery system with an evaporator
26 and a recovery furnace 30. The black liquor in line 22 is subjected to evaporation
in an evaporator 26 before passage to a recovery furnace 30. See column 2, lines 48-
53. Accordingly, we conclude that there is no suggestion or teaching in Reeve of using
two separate recovery systems. We add only that Reeve is directed to a chlorine dioxide
bleach plant, column 4, line 27. Accordingly, it is not seen why the person of ordinary
skill in the art concerned with a total chlorine-free bleaching operation would look to a
process directed to chlorine bleaching.
Finally, Ahlstrom is directed to chlorine-free bleaching and discloses a filtrate
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