Appeal No. 94-4357
Application No. 07/739,050
removing at least some of said contaminants to produce a
recycle gas; and
directing said recycle gas into the ozone generator to
provide at least a portion of said oxygen containing feed gas;
wherein said step of removing contaminants comprises
removing entrained pulp fibers from said exhaust gas; removing
ozone and a portion of the carbon monoxide by passing the gas
through a thermal destruct unit; removing hydrocarbons and the
remaining carbon monoxide from the gas which exits the thermal
destruct unit; purging a portion of the exhaust gas; forming
the recycle gas by cooling and drying the unpurged portion of
said exhaust gas; and mixing said recycle gas with fresh
oxygen containing gas to form the feed gas, thus maintaining
the concentration of carbon dioxide in the feed gas at a level
of about 6 wt. % to allow approximately full capacity
operation of the ozone generator.
13. A method for conditioning an ozone gas recycle
stream in an ozone pulp bleaching process, comprising:
providing an oxygen containing feed gas to an ozone
generator;
generating ozone from said feed gas to produce an ozone
rich oxygen gas;
increasing the consistency of a pulp;
bleaching the increased consistency pulp with said ozone
rich oxygen gas, thereby producing an exhaust gas containing
contaminants including carbon dioxide;
producing a recycle gas by removing ozone and purging a
portion of the exhaust gas to remove at least some of said
contaminants including carbon dioxide in an amount sufficient
to allow operation of the ozone generator at or approaching
full capacity;
3
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next
Last modified: November 3, 2007