[미국특허]
Method and apparatus for treating pulp with oxygen in a multi-stage bleaching sequence
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
D21C-009/12
D21C-009/14
D21C-009/16
D21D-005/28
출원번호
US-0048936
(1979-06-15)
발명자
/ 주소
Torregrossa Louis O. (Puyallup WA) Bentvelzen Jozef M. (Sumner WA) Crosby Gerald D. (Seattle WA) Meredith Michael D. (Federal Way WA) Bepple Henry (Kamloops CAX)
출원인 / 주소
Weyerhaeuser Company (Tacoma WA 02)
인용정보
피인용 횟수 :
29인용 특허 :
4
초록▼
A wood pulp slurry is treated with oxygen in a mill with little change to the process or structure of the mill. No special pressure tanks are required. The consistency of the pulp need not be altered for the treatment step. It may be treated at the usual process consistency of the pulp; e.g., it may
A wood pulp slurry is treated with oxygen in a mill with little change to the process or structure of the mill. No special pressure tanks are required. The consistency of the pulp need not be altered for the treatment step. It may be treated at the usual process consistency of the pulp; e.g., it may be treated at the usual consistency of the pulp leaving a washer or subsequent steam mixer without additional dewatering or additional dilution. The oxygen is added into a closed section of the system so that it cannot immediately vent to the atmosphere. Alkali should also be present when the oxygen is mixed with the slurry. The mixing should occur near to the point of oxygen addition. The mixing occurs in a relatively small mixer that intensively mixes the slurry and gas. The mixer has a mixing zone with a swept area of 10,000 to 1,000,000 square meters per metric ton of oven-dry pulp. A preferred range is 25,000 to 150,000 square meters per metric ton of oven-dry pulp and an optimum range of around 65,400 square meters per metric ton of oven-dry pulp. The pulp is treated several times during a sequence. Some sequences are O-X-O and O-O-X-O in which X may be chlorine, chlorine dioxide, a combination of chlorine and chlorine dioxide - mixture of chlorine and chlorine dioxide, CD, Dc -, hypochlorite, peroxide and ozone. The sequence may be followed by a D stage. Other systems and specific mixer designs are also disclosed.
대표청구항▼
The process of bleaching pulp comprising treating pulp at a consistency of 7 to 15% with oxygen at an alkaline pH and a temperature of around 65°C. to around 121°C., washing said oxygen treated pulp, treating said washed pulp with a bleaching chemical selected from a group consisting of chlorine, ch
The process of bleaching pulp comprising treating pulp at a consistency of 7 to 15% with oxygen at an alkaline pH and a temperature of around 65°C. to around 121°C., washing said oxygen treated pulp, treating said washed pulp with a bleaching chemical selected from a group consisting of chlorine, chlorine dioxide, combinations of chlorine and chlorine dioxide, hypochlorites, peroxides and ozone, washing said bleaching chemical treated pulp, and treating said latter washed pulp at a consistency of 7 to 15% with oxygen at an alkaline pH and a temperature of around 65°C. to around 121°C., said oxygen in each of said oxygen treatments being mixed with said pulp in a mixing zone in which a plurality of rotating members pass through said pulp in a direction transverse the direction of travel of said pulp, said members having a major axis extending in the direction of rotation, said members providing a swept area through said pulp of 10,000 to 1,000,000 square meters per metric ton of oven dry pulp, said members having leading and trailing edges, said leading edge having a radius of curvature in the range of 0.5 to 15 mm. A pulping apparatus comprising first means for adding a pH adjustment chemical to pulp, second means after said first means for adding oxygen to said pulp, third means for mixing said oxygen with said pulp, fourth means after said third means for washing said oxygen treated pulp, fifth means after said fourth means for adding a chemical selected from the group consisting of chlorine, chlorine dioxide, a combination of chlorine and chlorine dioxide, hypochlorite, peroxide and ozone to said pulp, sixth means for mixing said latter chemical with said pulp, seventh means after said sixth means for washing said pulp, eighth means after said seventh means for adding a pH adjustment chemical to said pulp, ninth means after said eighth means for adding oxygen to said pulp, tenth means for mixing said oxygen with said pulp, eleventh means for transporting said pulp from said first through tenth means, each of said oxygen mixing means having a mixing zone, a plurality or rotors in said mixing zone, said rotors having leading and trailing edges, said leading edge having a radius of curvature in the range of 0.5 to 15 mm, said rotors having a major axis extending in the direction of rotation, said rotors being rotatable through said pulp in a direction transverse to the direction of travel of said pulp, means for rotating said rotors, and said rotors providing a swept area of 10,000 to 1,000,000 square meters per metric ton of oven dry pulp.
Carlsmith Lawrence Allan ; Vote A. Sean ; Luthi Oscar ; Abdulmassih Anthony G., Apparatus for producing small particles from high consistency wood pulp.
James E. Sealey, II ; W. Harvey Persinger, Jr. ; Mengkui Luo ; Vincent A. Roscelli ; Amar N. Neogi, Lyocell fiber made from alkaline pulp having low average degree of polymerization values.
White David E. (Pennington NJ) Pikulin Michael A. (Bound Brook NJ) Gandek Thomas P. (Trenton NJ) Friend William H. (Savannah GA), Method of bleaching high consistency pulp with ozone.
Sealey, II,James E.; Persinger, Jr.,W. Harvey; Luo,Mengkui; Roscelli,Vincent A.; Neogi,Amar N., Process for making a composition for conversion to lyocell fiber from an alkaline pulp having low average degree of polymerization values.
James E. Sealey, II ; W. Harvey Persinger, Jr. ; Mengkui Luo ; Vincent A. Roscelli ; Amar N. Neogi, Process for making lyocell fibers from alkaline pulp having low average degree of polymerization values.
White David E. ; Pikulin Michael A. ; Gandck Thomas P. ; Friend William H., Pulp bleaching reactor for dispersing high consistency pulp into a gaseous bleaching agent containing ozone.
White David E. (Pennington NJ) Pikulin Michael A. (Bound Brook NJ) Gandek Thomas P. (Trenton NJ) Friend William H. (Savannah GA), Reactor for bleaching high consistency pulp with ozone.
Gandek Thomas P. (Trenton NJ) Joseph James C. (Yardley PA) Pikulin Michael A. (Bound Brook NJ) Pangalos George (Plainsboro NJ) Bowden Philip E. (Franklin VA), Reduction of salt scale precipitation by control of process stream Ph and salt concentration.
Gandek Thomas P. (Trenton NJ) Joseph James C. (Yardley PA) Pikulin Michael A. (Bound Brook NJ) Pangalos George (Plainsboro NJ) Bowden Philip E. (Franklin VA), Reduction of salt scale precipitation by control of process stream pH and salt concentration.
Sealey, II, James E.; Persinger, Jr., W. Harvey; Luo, Mengkui; Wester, Brian, Sawdust alkaline pulp having low average degree of polymerization values and method of producing the same.
Sealey, II, James E.; Persinger, Jr., W. Harvey; Robarge, Kent; Luo, Mengkui, Use of thinnings and other low specific gravity wood for lyocell products.
Sealey, II, James E.; Persinger, Jr., W. Harvey; Robarge, Kent; Luo, Mengkui, Use of thinnings and other low specific gravity wood for lyocell products method.
Sealey, II, James E.; Persinger, Jr., W. Harvey; Robarge, Kent; Luo, Mengkui, Use of thinnings and other low specific gravity wood for lyocell pulps method.
Carlsmith Lawrence A. (Amherst NH) Vote A. Sean (Nashua NH) Luthi Oscar (Nashua NH) Abdulmassih Anthony G. (Hudson NH), Wood pulp ozone bleaching contactor.
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