Abstract: An apparatus for cleaning and cooling a liquor nozzle, the nozzle including at least a liquor tube for feeding liquor and chemicals into a furnace of a recovery boiler. The apparatus includes an outer casing tube, which defines a space whereto conduits are provided for introducing water and steam to generate an emulsion or a conduit for introducing emulsion generated by the water and steam and the surface of which is provided with openings, such as pores or holes, for discharging the emulsion formed by water and steam through the outer casing.

Abstract: The invention is related to a method for emptying a furnace floor in a soda recovery boiler when the soda recovery boiler is being shut down. The emptying may be started while smelt is still flowing in smelt spouts. The floor is emptied by sucking smelt from the furnace with a smelt eductor. The invention is also related to a device for removing smelt and wash water from a furnace of a soda recovery boiler by means of suction. Negative pressure is generated in the device by conducting pressurized gas into a suction pipe of the eductor so that the pressurized gas is discharged in the discharge direction of smelt and wash water.

Abstract: A chemical pulp mill system and method of using black liquor flashing steam from a digester system comprises generating black liquor in the digester system, sending the black liquor to an evaporator system without using any pre-evaporator system, flashing the black liquor in the evaporator system to yield steam, and using at least some of the steam for chip steaming in a chip bin and/or for supplying in-direct heat exchangers in the digester system for pre-heating white liquor and/or filtrates for use in the digester system.

Abstract: An air conditioning system for use in an over-the-road or off road vehicle is provided that allows operation during both engine on and engine off conditions. The system utilizes a variable speed, motor driven compressor controlled by an intelligent power generation management controller. This controller selects from one of the available sources of power on the vehicle to drive the compressor, and modulates the compressor speed and capacity based on operational parameters and source availability and depletion. The controller may also operate a coolant or air heater to provide heating to the interior compartments.

Abstract: By the utilization of a jet ejector (such as a thermocompresser) in a cellulose chemical pulp mill, it is possible to effectively increase the utilization of steam. The volume of steam from a flash tank which flashes black liquor from a pulp digester may be increased (e.g. at least about 10%), while the volume and temperature of the liquor discharged from the flash tank are decreased and its concentration increased, by operatively connecting the jet ejector to the steam discharge from a flash tank. The jet ejector is supplied with higher pressure steam from another source which can result in a low pressure or partial vacuum condition in the flash tank. The flash tank may be a single flash tank or one of a series of flash tanks, and an ejector can be associated with at least another flash tank in the series.

Abstract: A continuous pulp digester having an elongate horizontally aligned pressure vessel through which the wood chips and digesting fluid flow in a forward direction. In a first and second embodiments within the pressure vessel there is an inner container defining an elongate chamber or passageway having a square cross sectional configuration. In a third embodiment the digesting chamber is cylindrical. At locations along the digester, there are several pair of liquid flow inlets and liquid flow outlets which enable filtrate from a pulp washer and a digesting agent to be moved into and across the digesting chamber to flow out the flow outlets. These are recirculated in a net upstream flow pattern toward the outlet end of the digester, and discharged as black liquor at different locations in the digester.

Abstract: An apparatus for introducing a high volume, low concentration non-condensable gas, which may contain sulfur into a chemical recovery steam generator furnace comprising: a plurality of gas inlet pipes, each gas inlet pipe having a source end and a nozzle end, in which the source end of the pipe is connected to a source of said high volume, low concentration non-condensable gas and the nozzle end of the pipe, which comprises a nozzle, vents to said chemical recovery steam generator furnace; a preheater positioned in close proximity to said pipe and upstream of said nozzle; a secondary air port with a source end and a furnace end, in which the source end of said port is connected to a source of such secondary air and the furnace end of said port vents to said chemical recovery steam generator furnace; wherein the area enclosed by said secondary air port is greater than the area of said nozzle and wherein said nozzle is positioned within the area enclosed by said secondary air port such that said pipe and said po

Abstract: Apparatus for a pulp and paper mill, and methods of acting on liquid effluents produced in the mill, which minimizes the discharge of polluting gaseous and liquid effluents to the environment. Liquid effluents from the bleach plant are concentrated (e.g. evaporated), incinerated (e.g. gasified), leached, crystallized (e.g. freeze crystallized) then washed, and then fed to the plant chemical recovery loop. White liquor produced from the recovery boiler melt is fully oxidized and used in place of caustic in the bleach plant. Essentially all sulfuric acid, sulfur dioxide, caustic, and chlorine dioxide necessary for the pulp mill is produced from mill liquid effluents and gas waste streams, on site at the pulp mill. Typical bleaching sequences that can be used are DE.sub.op D.sub.n D, or AZE.sub.o PZP.

Abstract: A spout for channeling smelt from a boiler through an opening in the walls of the boiler comprises a jacket having an inner wall and an outer wall. The outer wall is spaced a distance away from the inner wall and the jacket has one end insertable into the opening of the wall. The jacket defines a trough for carrying smelt from the boiler. An inlet communicates with the jacket for delivering a water flow to the jacket between the inner wall and the outer wall. An O-shaped tube communicates with the jacket at the inserted end of the jacket for receiving the water flow from between the inner wall and the outer wall of the jacket. An outlet communicates with the O-shaped tube near the inserted end for channeling the water flow from the O-shaped tube and out of the spout. A vacuum is used near the outlet for insuring a proper low pressure drop.

Abstract: The grit conveyance system of a classifier having a wash region above the liquid layer is provided with a vacuum means in the wash region for positive removal of liquids through a metal screen for disposal.

Abstract: The present invention relates to a method and apparatus for evaporating waste liquor produced when cooking fibrous material containing cellulose in a continuous pulp digester. In the continuous cooking process, fibrous material is heated to the process temperature by direct or indirect vapor heating in the digester at an increased pressure. The invention especially relates to digesters, in which fibrous material is heated directly with vapor.

Abstract: The number 2 flash tank of a black liquor energy recovery system associated with a continuous pulp digester is eliminated, and other advantages are obtained. After flashing in the number 1 flash tank, concentrated black liquor passes to a multiple effect evaporator system as the heating fluid supplied to the last effect. The heated black liquor passes in heat exchange relationship with excess make-up liquor from the high pressure feeder circulation system and/or with portions of the extracted black liquor that have had more of their heat content removed, the heated black liquor effecting evaporation of the excess make-up liquor and/or portions of the black liquor. Steam from the steam relief of the steaming vessel may be used as a secondary heating fluid source for the first effect.

Abstract: Method and apparatus for controlling the reactivity of lime produced in a lime cycle process that includes the steps of forming burnt lime in a kiln, washing and filtering of lime sludge, and causticizing of green liquor, which lime cycle process steps are carried out under variable operating conditions. At least one mechanical property of the burnt lime is measured, and at least one operating condition of the time cycle process is adjusted, based on the measured mechanical property of the burnt lime, so as to thereby control the reactivity of lime produced in the lime cycle process.

Abstract: In the cycle for production of pulp by the Kraft process, the active alkali concentration range in black liquor is monitored and adjusted. In recognition of the effect of the proportion of the active alkali to the other contents of the black liquor on a dry solids basis, active alkali is adjusted to control various performances of the evaporators and combustion within the recovery furnace.

Abstract: Apparatus is provided for controlling the degree of causticization of white liquor in its preparation from green liquor by the addition of calcium oxide, which comprises determining the sodium carbonate concentration of green liquor fed to the causticization; determining the sodium carbonate concentration of white liquor resulting from the causticization; and controlling the degree of causticization within a predetermined range while taking both sodium carbonate concentrations into account, so as to maintain the degree of causticization of the white liquor within the range despite variations in sodium carbonate concentration of the green liquor and variations in calcium oxide content of the calcium oxide added for causticization.

Abstract: An apparatus for treating a water solution of a waste material containing a salt with smelt-water explosion characteristics comprises an open-bottomed incinerator and a gas-liquid separator disposed beneath the incinerator in fluid-flow communication therewith. The waste solution is sprayed into the incinerator and heated therein so that the salt in the solution is fused, water vaporized and organic components of the solution burned. The combustion gases and water vapor flow downwardly into the separator, while the fused salt forms a deposit on the inner surface of the incinerator and flows downwardly into the separator. At the junction between the incinerator and separator, cooling water is fed to the fused salt so that the deposit of salt is solidified and cracked into separate masses which fall together with the cooling water onto an inclined baffle member disposed in the separator and roll downwardly on the baffle member.

Abstract: An alkali metal-containing spent liquor is treated to recover the alkali metal content for reuse without the need for recycling furnace ash and forming solid pellets therefrom. A mixture of aluminum hydrate and alkali metal-containing waste liquor is directed through a heated furnace and dried to form granules of the aluminum hydrate and waste liquor solids, and the organic content of the granules are combusted and reacted to form granular alkali metal aluminate furnace ash. The granular furnace ash is removed from the furnace and treated to recover the alkali metal and to produce aluminum hydrate for reuse in the process.

Abstract: A process and apparatus for treating concentrated alkali metal-containing waste liquor to recover the alkali metal content for reuse includes the following steps and apparatus. Concentrated alkali metal-containing waste liquor is mixed with recycled alumina and formed into solid pellets by mixing the concentrated liquor-alumina mixture with recycled alkali metal aluminate furnace ash. The solid pellets are fed through a furnace operating at a temperature below the fusion temperature of the aluminate for combusting the organic portion of the pellets and reacting the alkali metal content thereof with the alumina to form additional alkali metal aluminate ash. A portion of the furnace ash is recycled for reuse in the formation of pellets, while another portion of the ash is dissolved in water to form a solution of alkali metal aluminate. The alkali metal aluminate solution is mixed with slurry recycled from later in the process to initiate limited precipitation of alumina from the alkali metal aluminate.

Abstract: A non water cooled smelt spout for a pulp mill chemical recovery furnace. The spout is constructed from insulating and refractory material contained in a metal trough and is provided with a steam jet immediately adjacent the bottom free end of the spout. The jet impairs the formation of slag on the bottom of the trough and disintegrates the smelt stream issuing from the spout. Preferably the steam passage leading to the jet or nozzle extends along the bottom of the spout whereby the steam forming the jet also cools the bottom wall.

Abstract: A new chemical recovery process and apparatus for a polysulfide pulping system is described wherein sulfur is recovered from the weak black liquor and is returned to the process, along with makeup sulfur, to reconstitute the polysulfide solution.After the polysulfide digestion, the spent liquor is contacted with ferric oxide Fe.sub.2 O.sub.3 whereby ferrous sulfide, FeS, is formed. After separation of the ferrous sulfide from the remaining liquid, the ferrous sulfide is oxidized to form elemental sulfur, and ferric oxide. After the melting of the sulfur and the separating of the products, the sulfur can be returned to the Sulfur Dissolving Tank wherein, along with makeup sulfur as required, the white liquor from the causticizing plant can be treated to form the polysulfide liquor for digestion. The ferric oxide can be reused for contacting the black liquor to form ferrous sulfide. The resulting smelt of reduced sulfidity from the recovery furnace can be reprocessed to form the white liquor.