Abstract: An in-line drainer or liquid separator for draining liquid from a moving black liquor slurry stream having a screen basket mounted in the internal chamber of the in-line drainer. The screen basket includes slots to retain solid particles of the moving black liquor slurry stream within the black liquor slurry stream flow chamber and block the solid particles from entering the liquid collection chamber. The slots each have a curved corner edge adjacent a surface screen basket facing the black liquor slurry stream flow chamber.

Abstract: A top separator assembly for a digester is disclosed comprising: a rotatable shaft for the top separator; a packing for the shaft; and a sealing ring operatively mounted to the shaft and having a nominal clearance with the pack box, said sealing ring mounted so that up lifting of said shaft provides a substantially fluid tight seal between said pack box and a side of said ring (in the digester) opposite the pack box.

Abstract: A top separator assembly for a digester is disclosed comprising: a rotatable shaft for the top separator; a packing for the shaft; and a sealing ring operatively mounted to the shaft and having a nominal clearance with the pack box, said sealing ring mounted so that up lifting of said shaft provides a substantially fluid tight seal between said pack box and a side of said ring (in the digester) opposite the pack box.

Abstract: The flow of a liquid slurry of comminuted cellulosic fibrous material (e.g. wood chips) in a vertical vessel is made more uniform by providing a plurality of vertically spaced sets of either substantially continuous or discontinuous protrusions which extend inwardly from the internal surface of the vessel a maximum distance of between about 2-12 inches. A preferred vessel is a continuous or batch digester. The protrusions may have an arcuate, rectangular, isosceles or scalene triangular, right triangular, or trapezoidal cross-section, and may be spaced from each other vertically between about 1-12 feet, and have a height of between about 1-3 feet. Discontinuous protrusions have a preferred arcuate spacing of between 1-10 feet.

Abstract: Dense, tramp material, is efficiently separated in a comminuted cellulosic fibrous material feed system, for example in a chemical cellulose digester feed system, in a simple but effective matter. By merely utilizing a generally vertical conduit and a slurry flow within it (which may be augmented by high speed liquid introduction), that is caused to turn in a radiused path, centrifugal force allows separation of the tramp material into a cavity beneath the radius transition without requiring any mechanical element to engage the slurry. Appropriate purges, baffles, and discharge mechanisms may be provided. Alternatively, a tramp material separator may be built into an otherwise conventional metering screw in a digester feed system, or one or more centrifugal separators can be provided downstream of the slurry pump in a chip slurry transport system or digester feed system.

Abstract: A method in connection with continuous cooking of chips that comprises impregnating the chips with a impregnation liquid in an impregnation vessel and cooking the impregnated chips in a digester. The impregnation vessel and digester are connected to one another by means of a transfer circulation, which partly, via a feed line feeds the chips from an outlet end of the impregnation vessel to the top of the digester for separation of a free liquid in a separator. The separated liquid from the top of the digester is, partly, via a return line fed to the outlet end of the impregnation vessel for use as a transfer liqid for the impregnated chips to which cooking liquid is added to the chips at the top of the digester. Less than 100%, preferably less than 95%, and more preferred less than 90% of the liquid that is separated from the chips in the transfer circulation is recirculated to the used as transfer liquid.

Abstract: A new and improved way of continuously cooking fiber material, wherein temperatures and alkaline levels are controlled to be maintained within specific levels in different zones of the digesting process in order to optimize chemical consumption and heat-economy and at the same time achieve very good pulp properties. The digesting process includes a top separator that separates the transport liquid from the fiber material and permits the fiber material to be exposed to the cooking liquid.

Abstract: A new and improved way of continuously cooking fiber material, wherein temperatures and alkaline levels are controlled to be maintained within specific levels in different zones of the digesting process in order to optimize chemical consumption and heat-economy and at the same time achieve very good pulp properties. The digesting process includes a top separator that separates the transport liquid from the fiber material and permits the fiber material to be exposed to the cooking liquid.

Abstract: A method and apparatus for the continuous production of cellulosic pulp for use in a papermaking process. The apparatus includes a vessel containing a pulping liquor and the vessel consists of a first impregnation zone and a second attrition zone. Wood chips are continuously fed into the upper end of the first zone and are subject to gentle agitation to impregnate the chips with the liquor. The impregnated chips then flow into the second zone where they are heated to a low temperature of 80.degree. to 120.degree. C. and subjected to more severe agitation to break down the chips and liberate the individual fibers. The liquid level in the first zone is higher than in the second zone, causing the liquid to flow upwardly in the second zone with the cooking liquor and the liberated fibers being continuously discharged from the upper end of the second zone, while larger wood chips are retained in the second zone for further attrition.

Abstract: A versatile process and apparatus is presented for producing, in high yields, many different grades of pulp from a single wood specie or for pulping any specie or type of woody material, and for storage and recycling of the by-product liquid and gaseous materials. The process of this invention is virtually pollution free, and the reactant chemicals are recoverable from the by-products. In the alternative, the by-products themselves have a commercial value which may forestall recovery of the reactants. The lignin constituent extracted from the pulp is usable as a resin binder, a wood rehardening agent, or a glue.