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1.发明公开
公开(公告)号：EP0797703A1
公开(公告)日：1997-10-01
申请号：EP95926123.0
申请日：1995-06-29
发明人： SHACKFORD, Lewis, D. , MILLER, William, J. , ROY, Brian, P. , VAN LIEROP, Barbara , BERRY, Richard, M.
IPC分类号： D21C9
CPC分类号： D21C9/1026 , D21C9/1057 , D21C9/163
摘要： A method for bleaching cellulosic and lignocellulosic pulp using hydrogen peroxide as a bleaching reagent, utilizes a two-step reaction, viz. a short high temperature step at a pressure sufficient to suppress boiling and a longer atmospheric pressure reduced temperature step to consume a substantial portion of the hydrogen peroxide remaining after the short phase. The method includes the steps of introducing pulp (15), at a consistency of 10 %-18 %, to a mixer (100) in which the pulp is heated to a temperature above 100 °C; adding sufficient sodium hydroxide to bring the pulp to a pH of 8.5; adding sufficient hydrogen peroxide (36) to equal from about 0.5 %-5.0 %, by weight, of the pulp; passing the pulp through a pressurized reactor column (400) at a rate providing a reaction time in the column of between 1 and 30 minutes; and depositing the pulp in a reaction tower and allowing the reaction to proceed for 1-5 hours until a substantial portion of the residual hydrogen peroxide has been consumed. It may be desirable to introduce the pulp to a mixer and add alkali to reactivate residual hydrogen peroxide by bringing the pulp to a pH of at least 9 between bleaching steps.
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2.发明授权
公开(公告)号：EP0797703B1
公开(公告)日：2000-02-09
申请号：EP95926123.1
申请日：1995-06-29
发明人： SHACKFORD, Lewis, D. , MILLER, William, J. , ROY, Brian, P. , VAN LIEROP, Barbara , BERRY, Richard, M.
CPC分类号： D21C9/1026 , D21C9/1057 , D21C9/163
摘要： A method for bleaching cellulosic and lignocellulosic pulp using hydrogen peroxide as a bleaching reagent, utilizes a two-step reaction, viz. a short high temperature step at a pressure sufficient to suppress boiling and a longer atmospheric pressure reduced temperature step to consume a substantial portion of the hydrogen peroxide remaining after the short phase. The method includes the steps of introducing pulp (15), at a consistency of 10 %-18 %, to a mixer (100) in which the pulp is heated to a temperature above 100 DEG C; adding sufficient sodium hydroxide to bring the pulp to a pH of 8.5; adding sufficient hydrogen peroxide (36) to equal from about 0.5 %-5.0 %, by weight, of the pulp; passing the pulp through a pressurized reactor column (400) at a rate providing a reaction time in the column of between 1 and 30 minutes; and depositing the pulp in a reaction tower and allowing the reaction to proceed for 1-5 hours until a substantial portion of the residual hydrogen peroxide has been consumed. It may be desirable to introduce the pulp to a mixer and add alkali to reactivate residual hydrogen peroxide by bringing the pulp to a pH of at least 9 between bleaching steps.
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3.发明公开
公开(公告)号：EP0840820A1
公开(公告)日：1998-05-13
申请号：EP96928093.0
申请日：1996-07-16
IPC分类号： D21C9
摘要： A method and apparatus for bleaching pulp with a gaseous bleaching reagent. The pulp (18) is intensively mixed in the presence of the bleaching reagent within an upstream vessel comprising a fluffer/blower (12). Next, the pulp is agitated in the presence of the bleaching reagent within an intermediate vessel comprising an agitated mixer reactor (14). The pulp is then discharged to a downstream vessel, comprising a porous bed reactor (16), where it is further reacted with the bleaching reagent. The concentration of the gaseous bleaching reagent supplied to each vessel is separately controlled which, in combination with a controlled pulp residence time within at least the agitated mixer reactor and the porous bed reactor, results in an economy of energy utilization, a minimization of pulp particle damage due to mechanical mixing, and uniformity of pulp bleaching.
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4.发明公开METHOD AND APPARATUS FOR BLEACHING HIGH CONSISTENCY PULP WITH A GASEOUS BLEACHING REAGENT 失效方法和设备漂白纸浆与气态BLEACH HIGH一致的
公开(公告)号：EP0846198A2
公开(公告)日：1998-06-10
申请号：EP96926928.0
申请日：1996-07-16
IPC分类号： D21C9
摘要： A method and apparatus for bleaching hig consistency pulp with a gaseous bleaching reagent. The pulp is shredded and then fluffed in the presence of a contacting gas which includes the gaseous bleaching reagent within an upstream vessel (52) comprising a pin/foil contactor so as to suspend the pulp in the contacting gas and react the bleaching reagent with the pulp. The pulp is retained in the contactor for a predetermined time which is sufficient to consume about 75 % to about 90 % of a selected dose of the gaseous bleaching reagent which is required to delignify the high consistency pulp from an initial Kappa number to an intermediate Kappa number. The pulp and contacting gas are then separately supplied to a porous bed reactor where the reaction of the selected dose of the gaseous bleaching reagent with the pulp is substantially completed so as to further delignify the high consistency pulp from the intermediate Kappa number to a final Kappa number.
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5.发明授权
公开(公告)号：EP0840820B1
公开(公告)日：1999-04-28
申请号：EP96928093.2
申请日：1996-07-16
摘要： A method and apparatus for bleaching pulp with a gaseous bleaching reagent. The pulp (18) is intensively mixed in the presence of the bleaching reagent within an upstream vessel comprising a fluffer/blower (12). Next, the pulp is agitated in the presence of the bleaching reagent within an intermediate vessel comprising an agitated mixer reactor (14). The pulp is then discharged to a downstream vessel, comprising a porous bed reactor (16), where it is further reacted with the bleaching reagent. The concentration of the gaseous bleaching reagent supplied to each vessel is separately controlled which, in combination with a controlled pulp residence time within at least the agitated mixer reactor and the porous bed reactor, results in an economy of energy utilization, a minimization of pulp particle damage due to mechanical mixing, and uniformity of pulp bleaching.
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