Kamyr, Inc.

Oliver A Laakso

Michael I Sherman

Erwin D Funk

James R Prough

In an apparatus for treating cellulose pulp with oxygen gas by passing the pulp and oxygen gas through a reaction vessel at elevated temperature and pressure, the improvement whereby the exothermic heat of reaction is controlled and the temperature of the pulp being treated is maintained below the point where the pulp would be degraded, the improvement comprising means for withdrawing oxygen gas from the vessel after the gas has been in contact with the pulp, dividing the withdrawn gas into two portions, cooling one of the portions to remove water vapor therefrom, recombining the gas portions whereby the resulting gas has a lower temperature than the gas withdrawn from the vessel and returning the resulting gas to the vessel for further contact with pulp therein, the amount of gas withdrawn from the vessel and the degree of cooling of the cooled portion of withdrawn gas being regulated to maintain the temperature within the vessel below the point where the pulp is degraded.

Apparatus for delignifying and bleaching cellulose pulp

A method is provided for recovery of white liquor and sodium hydroxide following the oxygen bleaching of pulp. A green liquor recovery system concentrates the spent black liquor, including spent liquor from the oxygen bleaching and spent black liquor, and then burns the spent liquor to form a smelt. This smelt is then dissolved in water to form the green liquor. The green liquor is divided into a first portion which is fed to a sodium hydroxide recovery system for recycling to the oxygen bleaching reactor and a second portion which is fed to a white liquor recovery system for recycling to the digester. A lime cycle is also provided to convert the resulting calcium carbonate (lime mud) to calcium oxide for recycling into the sodium hydroxide and white liquor recovery systems.

Recovery system for oxygen bleaching of pulp

Apparatus and method for digestion of cellulose material in a continuous digestion process, that do not require screens in the outlet of the digesting zone. Cellulose chips and digesting liquid at relatively low temperature are introduced into a relatively long and thin cylindrical impregnation vessel, having a first diameter. The chips from the impregnation vessel pass into a digestion vessel having a second diameter substantially greater than the first diameter, the outlet for the impregnation zone into the digestion vessel being disposed well into the digestion vessel and below an outlet(s) disposed in the top of the digestion vessel, and form a chips column in the digestion vessel. Digesting liquid at a relatively high temperature is introduced into contact with the chips, at a point a significant distance below the impregnation vessel outlet, and the quantity of digesting liquid being introduced and the first and second diameters are so arranged that the velocity of liquid flowing to the digestion vessel top outlet is substantially less than the velocity of liquid that would entrain significant numbers of particles therein, whereby a clarifying section is provided between the chips column and digestion vessel outlet so that the need for screens at the outlet is eliminated. A pair of vertically arranged screens which are alternately connected to a suction source may be provided in the clarifying section between the top of the chips column and the outlet to remove any particles that might be entrained in the liquid therein from the liquid.

Method and apparatus for digesting cellulose material without screening

Apparatus for refining digested pulp involving the use of a refiner, preferably two or more refiners in series positioned in the digester blow line to receive washed, digested pulp discharged from a continuous digester.

Apparatus for processing pulp

An improved system for the production of digested pulp from wood chips and knots which includes a separating apparatus, connected to the digester output, capable of separating knots from partially cooked wood chips and fibers at the digester pressure and consistency. The separated fibers and fiber bundles pass to a refiner where the fiber bundles are mechanically reduced to fibers in a liquid environment at a high consistency and at the digester pressure. The knots are then re-cycled to the digester or other processes. The separating apparatus above uses a plurality of rotating members such as intermeshing screws or grooved rolls, arranged in a vertical screen to separate an inlet chamber from an outlet chamber. Knots cannot pass through the rotating members and thus are driven out of an outlet which communicates with the inlet chamber. The fibers, however, do pass through the rotating members to the outlet chamber and exit therefrom by a second outlet.

Apparatus for separating knots from pulp

A process for providing pressurized, pulverized coal for use in combustion or gasifying of coal by the fluidized bed or suspended particle combustion principles which comprises the steps of introducing lump coal, of stoker size to run of mine size, into a low energy liquid circulation stream; transferring the lump coal to a high energy, high pressure, liquid circulation stream; separating the lump coal from the high energy liquid circulation stream by lifting the coal through a free liquid surface, said high energy liquid draining from the coal by gravity; directing the coal by gravity transfer to a continuous mechanical dryer for removal of surface liquid; gravity transfer to a coal crusher for major size reduction; gravity transfer to a coal pulverizer for size reduction necessary for the gasification processes; transfer of pulverized coal by gas circulation from the pulverizer to a cyclone separator, said circulating gas used in the pulverizer for coal particle classifying; and final injection of the pulverized coal to a fluidized bed or suspended flow coal gasifier or any pressurized combustion chamber, and apparatus for carrying out the process comprising a combination of known components.

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Glens Falls, NY, United States of America

Oliver A Laakso