Abstract: A cyclic process is provided for utilizing sodium values in sulfate cellulose pulping, in which sodium losses normally are less than sodium additions to the process, thus tending to build up a sodium surplus, and which includes the steps of pulping cellulosic material with a pulping liquor comprising sodium hydroxide and sodium sulfide, separating spent pulping black liquor, evaporating and combusting the black liquor to recover sodium values as sodium sulfide and sodium carbonate, dissolving the sulfide and sodium carbonate in water to form green liquor, causticizing the green liquor with calcium hydroxide to form white liquor, and recycling white liquor to form pulping liquor, the improvement comprising maintaining sodium balance at least in part by removing sodium values as white liquor, oxidizing the white liquor with air at an elevated temperature, and utilizing the oxidized white liquor as a source of alkali in another cellulose pulp treatment process.
Type:
Grant
Filed:
April 26, 1976
Date of Patent:
October 11, 1977
Assignee:
Mo och Domsjo Aktiebolag
Inventors:
Bengt Goran Hultman, Sture Erik Olof Noreus
Abstract: Process for improving the selectivity of delignification of lignocellulosic material in the presence of oxygen gas and alkali by maintaining a carbon monoxide content in the gas phase within the range from about 1% to about 12% by volume. The carbon monoxide concentration is maintained by withdrawing carbon monoxide and oxygen gas from the delignification, and separating and recycling withdrawn oxygen gas.
Type:
Grant
Filed:
June 11, 1975
Date of Patent:
September 27, 1977
Assignee:
Mo och Domsjo Aktiebolag
Inventors:
Allan Geoffrey Jamieson, Hans Olof Samuelson, Leif Ake Smedman, Kent Ivar Sondell
Abstract: Asphalt compositions are provided having improved adhesion to aggregate, comprising an alkyl oxyalkylene amine and, optionally, an alkanolamine.
Type:
Grant
Filed:
June 13, 1975
Date of Patent:
July 26, 1977
Assignee:
Mo Och Domsjo
Inventors:
Martin Edvin Hellsten, Anders William Klingberg, Stig Erick Svennberg
Abstract: A process for the preparation of a cellulose pulp by mechanically freeing wood fibers in a grinder to form a fibrous pulp and bleaching the fibrous pulp with a peroxide-containing bleaching agent, as the only bleaching agent, in a peroxide bleaching stage, the mechanical freeing of the fibers being carried out in the presence of a spent liquor from the peroxide bleaching stage have a pH of 7 to 9.
Abstract: A process is provided for delignifying and bleaching cellulose pulp, which comprises carrying out the delignification and bleaching with oxygen and alkali in the presence of sodium bicarbonate, while removing carbon dioxide from the gas phase as required to maintain a carbon dioxide partial pressure within the range from about 0.001 to about 3 bars, thereby improving the selectivity of the delignification and bleaching.
Abstract: A method for improving heat economy in the batchwise digestion of lignocellulosic material especially when using a batch digester with a digestion or cooking liquor in which the digestion or cooking chemicals are dissolved, such as in sulphate, sulphite, bisulphite, oxygen, peroxide and ammonium hydroxide digestion processes, and also in the manufacture of high yield semichemical pulps.A superatmospheric gas pressure is applied above the level of the liquor in a batch digester; the level of the digester liquor is determined after the liquor has been absorbed by a batch lignocellulosic material; the level of free digestion liquor is then adjusted to that level providing an amount including the absorbed liquor to digest the lignocellulosic material; and then the material is digested under the superatmospheric pressure to form cellulose pulp.
Type:
Grant
Filed:
October 17, 1974
Date of Patent:
March 1, 1977
Assignee:
Mo och Domsjo
Inventors:
Ulf Torbjorn Olson, Erik Olof Sture Hagglund
Abstract: A process is provided for freeing cellulose fibers from lignocellulosic material, which comprises subjecting particulate lignocellulosic material to irradiation at a frequency within the range from about 10 to about 300,000 MHz (megahertz), at an intensity of at least 0.5 megajoule per kg. of material, applied in a short pulse having a duration of at most 0.1 second, at such an intensity the water present in the lignocellulosic material is rapidly and even explosively vaporized, and disrupts or destroys the natural structure of the lignocellulosic material, thereby freeing the fibers substantially without deleterious effect upon the length or strength of the fibers.
Type:
Grant
Filed:
September 23, 1975
Date of Patent:
December 28, 1976
Assignee:
Mo och Domsjo
Inventors:
John Rickard Bergstrom, Ernst Birger Tiberg
Abstract: A planting machine is provided having a pneumatic depth indicator on the digging tool and comprising at least one gas conduit for conveying a gas under superatmospheric pressure from one end to the other end thereof, the one end being connected to a gas supply source, and the other end being open to atmosphere and spaced a distance from the digging tool end equal to the depth of the hole dug by the tool for a plant, the other end being so arranged that the opening to atmosphere is plunged into blocking contact to the earth when the predetermined hole depth is reached, thereby halting flow of gas from the conduit.
Abstract: An absorbent, disposable sanitary device for insertion in a body cavity, and especially intended for insertion into the vagina to absorb menstrual fluid therein, comprising a resilient rotund absorbent fibrous layer which retains its resiliency when wet and in which fibers are bonded together, supported on a core of stiff material, and means attached to the core to facilitate removal of the device from the vagina or other body cavity.
Type:
Grant
Filed:
May 9, 1975
Date of Patent:
October 19, 1976
Assignee:
Mo och Domsjo
Inventors:
Elisabet Olofsson, Bernt Johansson, Hans-Ivar Eriksson
Abstract: Process and apparatus are provided for turning logs arranged in a row so that the root ends of all the logs are pointed in the same direction. A log whose root end is to be re-oriented is gripped while being conveyed along a first conveying path, and while proceeding in the conveying direction, and turned about an axis equidistant from both ends of the log, after which the turned log is placed on a second conveying path.
Abstract: A method is provided for controlling the amount of oxidizing bleaching agents in liquors used within the cellulose industry, as in the bleaching of sulphite, sulphate, mechanical, chemimechanical, semichemical or similar cellulose pulps, and in related industries, and particularly for controlling the addition of oxidizing bleaching agents to the system during the bleaching of cellulose pulp by mixing such liquor with at least one chemiluminescent reagent which reacts with the oxidizing bleaching agents in a manner to emit light. The amount of oxidizing bleaching agents in the liquor is then determined by comparison of the light intensity thus obtained with the light intensity for previously measured calibration values corresponding to known quantities of such oxidizing bleaching agents, and then from such determination controlling the addition of such oxidizing bleaching agents to the liquor.
Type:
Grant
Filed:
October 17, 1974
Date of Patent:
June 8, 1976
Assignee:
Mo och Domsjo AB
Inventors:
Karl Gustav Gunnar Wettermark, Per Ulf Isacsson, Bengt Goran Hultman, Per Henrik Otto Johan Norberg, Bo Nils Olof Lindahl
Abstract: A process for the manufacture of paper pulp from waste paper in which the waste paper is comminuted in water in a pulper, pre-cleaned for removal of coarse foreign contaminants, dewatered, kneaded at high concentration, diluted, after-cleaned for removal of finer or coherent soft foreign contaminants and adjusted to a concentration suitable for paper-making, the water respectively used for dilution and obtained during dewatering being circulated in two separate circuits upstream and downstream respectively of the kneading apparatus.
Abstract: A process is provided for producing cellulose pulp of high brightness, which comprises pulping lignocellulosic material such as wood with oxygen under superatmospheric pressure in two stages, in the first at a pH within the range from about 6 to about 9, and in the second at a more alkaline pH of at least about 10.
Type:
Grant
Filed:
December 12, 1973
Date of Patent:
March 16, 1976
Assignee:
Mo och Domsjo Aktiebolag
Inventors:
Hans Olof Samuelson, Leif Ake Smedman, Erik Olof Sture Hagglund
Abstract: A fully controllable process is provided for the manufacture of sulfate pulp having a predetermined degree of delignification and therefore a predetermined Kappa number. A sample of the pulping liquor is taken at a stage at which the preliminary alkali-consuming physical and chemical reactions and processes have substantially been completed, the sample is analysed to give the content of alkali in the liquor, and the alkali content adjusted to at least 20 g calculated as NaOH per kilogram of wood initially added, by addition of alkali. From this alkali content the pulping intensity expressed as "H" factor for obtaining the desired Kappa number is determined, and the pulping time and pulping temperature during delignification are controlled according to this H factor. It is also possible to adjust the alkali content in a controllable manner by injecting white liquor, black liquor or water into the digester. The process is applicable to continuous digesters as well as batch digesters.
Abstract: An apparatus is provided for cutting lengths of debranched trees or logs into shorter pieces, comprising a conveyor for carrying the logs sideways to and past a plurality of cutters arranged in groups, the cutters in each group being individually movable between active cutting and inactive noncutting positions, and into cutting positions over a determined span, and spaced apart along the path of travel of the logs so that only one cutter at a time in a given group cuts a log. Beyond the cutters, a means is provided for classifying the logs according to quality and dimensions, and then separating the classified logs for further cutting into lumber, pulping, or other processing, according to the use to which the log can be put.