69results about "Pulp liquors combustion" patented technology

The specification relates to a method and a system for adjusting pH of green liquor dregs. The method comprises contacting a slurry containing green liquor dregs (100, 200, 300, 400, 500) with flue gas (101, 201, 301, 401, 501). The system comprises a recovery boiler (105) configured to burn black liquor to produce smelt, a smelt dissolving tank (107) configured to dissolve the smelt to produce green liquor comprising green liquor dregs, and a green liquor clarifier / filter (103) and / or a dregs filter (104) configured to separate a slurry containing green liquor dregs (100, 200, 300, 400, 500) from the green liquor. The system further comprises a vessel (102, 202, 302, 402) configured to receive a slurry containing green liquor dregs (100, 200, 300, 400, 500) and a gas inlet (210, 310, 410, 510) configured to convey flue gas (101, 201, 301, 401, 501) to be contacted with the slurry containing green liquor dregs (100, 200, 300, 400, 500).

The application discloses a kind of low NOx emission combustion control method of alkali furnace based on flue gas recirculation.The method is transported to the third air duct by induced draft fan after part of flue gas after dust removal, and air-gas mixture is formed after mixing with air, and is injected into the hearth from the alkali furnace third air distribution port.The application obtains the temperature field, concentration field and thermal efficiency in the furnace by establishing the geometric structure model and numerical calculation model of alkali furnace, and obtaining by CFD calculation;By adjusting different flue gas recirculation rates, the influence of flue gas recirculation rate on the temperature field, concentration field and thermal efficiency in the furnace is simulated, and the optimized flue gas recirculation rate is obtained.The application can reduce the oxygen content of the third air, reduce the generation of NOx in the high-temperature combustion zone, reduce pollution emissions, at the same time, the increased recirculation flue gas flow is beneficial to reduce the temperature of the lower part of the superheater, and relieve high-temperature thermal stress corrosion.

Embodiments herein relate to a system 100 that for example may be used for calcination of lime mud. The system may comprise an input 102, a media separated heat exchanger 104, an injection arrangement 106, an electrically heated calcination reactor 108, configured to convert input material received by means of said injection arrangement 106 into calcination process products comprising a solid compound in the form of calcium oxide and a gas in the form of carbon dioxide, a heat recovery arrangement 116 configured to receive said calcination process products, to extract heat from said calcination process products and transfer said extracted heat to said input material in said media separated heat exchanger 104 and one or more separators 112, 118 configured to separate said solid compound in the form of calcium oxide and gas in the form of carbon dioxide. Different parts of the system 100 are exemplified in embodiments herein.

A startup burner assembly for a recovery boiler, the startup burner assembly includes a housing having a burner end and a second end distal to the burner end; a main fuel conduit disposed within the housing; and high-pressure air conduits disposed within the burner end of the housing. The high-pressure air conduits include angled air injection nozzles configured to direct high-pressure air exiting the burner end of the startup burner assembly in a rotational direction.

A method for clearing accumulated material deposits inside a furnace includes initiating a preprogrammed sequence to: position a robot to access an opening in a wall of the furnace; position an end effector of the robot at a specified angle for accessing the opening; operate the robot to cause the end effector to penetrate the accumulated material deposits; and retract the end effector.

The invention particularly relates to a dissolving pulp production process which comprises the following steps: washing and soaking wood chips or cotton linters, and naturally draining to obtain a pretreated raw material; adding adjusting water into the pretreated raw material, then adding sodium sulfite, mixing and stirring, heating and preserving heat, and extracting pre-hydrolysis waste liquid to obtain semi-slurry; the ratio of the absolute dry mass of the pretreated raw materials to the volume of the adjusting water is 1: (5-8); in terms of SO2, the use amount of sodium sulfite is 2%-4% of the absolute dry mass of the pretreated raw material; the heating and heat preservation temperature ranges from 150 DEG C to 160 DEG C, and the heat preservation time ranges from 90 min to 120 min; carrying out sulfate cooking on the semi-slurry to prepare coarse slurry and cooking black liquor; the coarse pulp is bleached, pulped and sieved by adopting an OD0EOPD1 section sequence, and the dissolving pulp is prepared. According to the method, the quality of the dissolving pulp is remarkably improved by adopting sodium sulfite to prehydrolyze the dissolving pulp, the high-end application requirements of cellulose acetate, Lyocell fibers and the like can be met, the vacuum pulp washing link of semi-pulp after prehydrolysis is omitted, the pulp wastage rate is reduced, the MVR evaporator utilizes secondary steam compression reuse, and the water resource utilization rate is improved.

The invention pertains to a process for the removal of a phosphorus-rich lime product from a kraft pulping process, wherein at least one, or at least part of one, phosphorus-containing waste stream from the from the kraft pulping process is purified resulting in a purified water fraction and a phosphorus-containing floc, the obtained dried phosphorus-containing floc is added to the spent liquor recovery process, resulting in a phosphorus-containing lime mud, part of which is removed as a phosphorus-rich lime product with a phosphorus content of at least 2 g / ton and a cadmium content in relation to phosphorus of not more than 100 g Cd / ton P. Further is provided a fertilizer product, comprising the phosphorus-rich lime product as a phosphorus component.

The invention discloses an alkali furnace low NOx emission combustion control method based on flue gas recirculation. According to the method, part of dedusted flue gas is conveyed to a tertiary air pipe through an induced draft fan and mixed with air to form air-flue gas mixed gas, and the air-flue gas mixed gas is injected into a hearth from a tertiary air distribution port of the alkali furnace. According to the method, a geometric structure model and a numerical calculation model of the alkali furnace are established, and a temperature field, a concentration field and heat efficiency in the furnace are obtained through CFD calculation; by adjusting different flue gas recirculation rates, the influence of the flue gas recirculation rate on the temperature field, the concentration field and the heat efficiency in the furnace is simulated, and the optimized flue gas recirculation rate is obtained. The oxygen content of tertiary air can be reduced, generation of NOx in a high-temperature combustion area is reduced, pollutant emission is reduced, and meanwhile, the temperature of the lower portion of the superheater can be reduced and high-temperature thermal stress corrosion can be relieved through the increased recirculating flue gas flow.

A method for recovering cellulose from a cellulose containing textile raw material containing dyed textiles, the method comprising subjecting a disintegrated textile raw material to an oxidative pretreatment before alkaline cooking and any further processing of the cellulose pulp obtained after the alkaline cooking. After cooking, spent alkaline cooking solution containing dye and dye residues is withdrawn from the textile derived cellulose pulp and is transferred to a recovery boiler in a Kraft pulp mill. An apparatus for carrying out the method is also disclosed.

The invention relates to the use of an object of an austenitic stainless alloy in high temperature and high-pressure environment wherein said austenitic stainless alloy comprises in weight%:C less than 0.03; Si less than 1.0; Mn less than or equal to 1.2; Cr26.0 to 30.0; Ni 29.0 to 37.0; Mo 6.1 to 7.1; N 0.25 to 0.36;P less than or equal to 0.04; Sless than or equal to 0.03; Cu less than or equal to 0.4; balance Fe and unavoidable impurities. The invention also relates to superheater comprising at least one object made of said steel.

The invention relates to a method of controlling a maintenance operation apparatus (10) of a recovery boiler (11) to carry out maintenance operation for an at least one maintenance object (S1-S14) at a recovery boiler (11) wherein the maintenance operation apparatus (10) comprises a maintenance tool (13) and a tool moving device (R1-R5) for moving the maintenance tool (13) to accomplish the maintenance operation, and wherein the method comprises method steps of a) defining a position of a fixed world coordinate system (20) at the recovery boiler (11), b) defining a position of an initial base coordinate system (21) of the at least one maintenance object (12) that is at a chosen point of the at least one maintenance object (S1-S14) determined in the fixed world coordinate system (20) in an initial temperature of the recovery boiler (11), c) defining a position of a corrected base coordinate system (22) of the at least one maintenance object (S1-S14) in the fixed world coordinate system (20) that is at the position of the chosen point in the fixed world coordinate system (20) in a transited temperature of the recovery boiler, (11), d) controlling the tool moving device (R1-R5) to carry out the maintenance operation of the at least one maintenance object (S1-S14) in the corrected base coordinate system (22). The invention relates also to a maintenance operation apparatus (10).

The invention relates to a method for clearing accumulated material deposits inside a hearth, comprising: initiating a pre-programmed sequence to position a robot proximate an opening on a recovery furnace wall; positioning an end effector of the robot at a designated angle for accessing the opening; operating the robot to cause the end effector to penetrate the accumulated material deposits; and retracting the end effector.

A calcination reactor arrangement (108,300), comprising an electrically heated primary calcination reactor chamber (222,302) having an inlet (312) for input material; a secondary calcination reactor chamber (223,306) configured to receive a flow of material from the primary calcination reactor chamber (222,302) and to maintain a flow of the material through the secondary reactor chamber (223,306).

A sodium recovery process (1) for recovering sodium salts from recovering sodium salts from ash in an ash treatment plant in a pulping mill, said sodium recovery process comprising the feature of mixing ash from burning of black liquor with a liquid to form an ash suspension by mixing ash and liquid in a ratio between 1:1,5 and 1:4 by weight, said ash suspension subjected to temperature between 40 and 100 degrees °C whereby sodium salts are precipitated and forming a stream of solids separated from the liquid phase, said liquid phase forming a purge (2), the sodium recovery process (1) further includes the steps of: - diluting the purge (2) by addition of 2 % by weight to 60 % by weight of water (8); cooling the purge (2) to a temperature of below 15 °C; - allowing sodium salts to precipitate from the cooled and diluted purge (2); - separating a liquid phase (12) from the precipitated sodium salts (11); - withdrawing the liquid phase (12) from a slurry (16) of the precipitated sodium salts (11).

Embodiments herein relate to a particle separator (110) for use in a calcination system (100). The calcination system (100) comprises an electrically heated calcination reactor (108) configured to convert input material into calcination process products. The particle separator (110) comprises a chamber (401) configured to hold a fluid bed (402) of particles mixed with gas, into which fluid bed (402) gas is fluing from underneath (403), thereby separating smaller particles from larger particles by lifting said smaller particles upwards in the flow of gas. The fluid bed (402) is coupled to a transfer channel (404) arranged to provide the flow of the separated smaller particles mixed with gas to an injection arrangement (106) injecting the provided input material into said electrically heated calcination reactor (108).

A method and system to determine one or more proportional particle group shares in flue gas of a recovery boiler (110) based on optical information gained from a flue gas sample. A processor (202) is used to read (301) a digital frame comprising the area under consideration, which represents at least a part of the surface of a sampler (120) kept in the flue gas flow of a recovery boiler. Particle group areas matching a color characteristic of the particle group comprised in the flue gas is determined (302) from the area under consideration. The joint area of the identified particle group areas is determined (304), and the share of the joint area from the total area is determined (305) as the proportional particle group share of the particle group.

A handling device for liquor guns (2) of a recovery boiler plant, which device comprises transfer means (11) for transferring a nozzle (7) of a liquor gun to the furnace (1) of a boiler and out from the furnace. In addition, the invention relates to a recovery boiler plant as well as a method in a recovery boiler plant.

The present invention relates to a method for reducing emissions from a recovery boiler, the method comprising the steps of spraying black liquor into a boiler furnace, burning the sprayed black liquor in the boiler furnace, generating steam by cooling flue gas of the burned black liquor through a heat exchanger, removing particles from the cooled flue gas using at least one electrostatic precipitator, passing the flue gas through at least one baghouse filter, further removing particles from the flue gas using bags in the at least one baghouse, and reducing flue gas emissions with an SCR catalytic process.

Embodiments herein relate to a heat recovery arrangement for heat recovery in a system 100 for calcination of lime mud. The heat recovery arrangement comprises: an inlet 402 for receiving incoming gas preheated by excess heat generated by the system 100; an expander 404 for expanding and thereby cooling by expansion said incoming preheated gas; a heat recovery tube 406 arranged in a container 408 comprising quick lime extracted from the system 100, into which recovery tube 410 said expanded and cooled gas is led and heated by the heat from the quick lime; a compressor 412 for compressing and further heating said preheated gas; and an outlet 414 from which said compressed and further heated gas is led out and thereafter decompressed by a diffusor 418 and reentered into the system 100, whereby heat generated from the calcination process is reused.

This utility model discloses an alkali recovery boiler for waste alkali purification, comprising: a spray gun holder disposed within the alkali recovery boiler; an inlet pipe disposed on one side of the spray gun holder; a spray gun assembly disposed on the top of the spray gun holder for spraying atomized and concentrated black liquor for combustion within the alkali recovery boiler; the spray gun assembly includes a spray gun head, multiple frustum-shaped nozzles on the spray gun head, and guide grooves disposed between the nozzles; a drive component disposed within the spray gun holder; and a cleaning component disposed on the spray gun assembly and fixedly installed with the drive component. The drive component drives the cleaning component to rotate, and the cleaning component cleans the inner and outer sides of the spray gun assembly and the nozzles to prevent clogging of the spray gun assembly. It also includes multiple arc-shaped plates disposed between two slip rings to drive the slip rings to rotate within the slip groove. This utility model achieves automatic cleaning of the black liquor spray gun nozzle, avoiding clogging and improving the service life of the nozzle.

The smelt breakup device includes an inlet orifice, an outlet orifice, and a fluid path between the inlet orifice and the outlet orifice. A converging-diverging zone is located between the inlet orifice and the outlet orifice. In one exemplary configuration, a first separable section includes the inlet orifice, and a second separable section includes the outlet orifice and a diverging zone of the converging-diverging zone. In some configurations, there may be a second outlet orifice in fluid communication with the inlet orifice. To provide uniformity across the multiple breakup jets, the first outlet orifice can have a cross-sectional dimension, and the second outlet orifice is positioned at a distance from the first outlet orifice that is between about 4 times and about 10 times the cross-sectional dimension.

Methods and systems for preparing non-wood agricultural feedstock material for use as a pulp, and making a paper product therefrom. The method includes providing non-wood agricultural feedstock material (e.g., corn stover) that includes agricultural fibers, chemically pulping the agricultural fibers at a low temperature of less than 100° C., refining the agricultural fibers (either before or after cooking), and introducing the produced agricultural fiber pulp into a papermaking machine to make liner, medium, tissue, towel, cardstock or other paper product (e.g., tubes, cores, chipboard, grayboard, or other rigid container board). The agricultural pulp fibers can also be introduced into a molded pulp products manufacturing machine, to make egg cartons, molded paper plates, molded single use packaging, or the like.

A method for obtaining information about a quality of combustion of a liquid in a chemical recovery boiler. The method comprises inputting a value of a first input parameter to a computational model configured to determine a value of the quality of combustion of the liquid in the chemical recovery boiler based on the value of the first input parameter, and first running the computational model to obtain a first modeling result. The method comprises measuring a value indicative of a carryover from the chemical recovery boiler to obtain a measurement result, comparing the first modeling result to [a] the measurement result or [b] a result derived from the measurement result to obtain a primary comparison result, and adjusting the value of the first input parameter based on the primary comparison result to obtain an adjusted value of the first input parameter. The method comprises inputting the adjusted value of the first input parameter to the computational model, and second running the computational model to obtain the information about the quality of combustion of the liquid in the chemical recovery boiler.

A boiler system is provided comprising: a furnace adapted to receive a fuel to be burned to generate hot working gases; a fuel supply structure associated with the furnace for supplying fuel to the furnace; a superheater section associated with the furnace and positioned to receive energy in the form of heat from the hot working gases; and a controller. The superheater section may comprise a platen including a tube structure with an end portion and a temperature sensor for measuring the temperature of the tube structure end portion and generating a signal indicative of the temperature of the tube structure end portion. The controller may be coupled to the temperature sensor for receiving and monitoring the signal from the sensor.

The disclosure provides methods and compositions for reducing the viscosity of black liquor. Also provided are methods of inhibiting deposition of scale and methods of processing black liquor. In some embodiments, the compositions include a carboxylate-containing polymer and an inorganic salt. In some embodiments, the compositions include a carboxylate-containing polymer, an inorganic salt, and a surfactant.

The invention relates to a method for treating ash recovered from a recovery boiler. The process is designed to recover valuable pulping chemicals, such as potassium, sodium, carbonates and sulfates. During the treatment of ash, a chloride-rich purge stream is produced and includes sulfates, carbonates, potassium and sodium that can be beneficially used in the wood pulping process. To separate chlorides from beneficial chemicals, a chloride-rich purge stream is directed to an anion separation unit (e.g., nanofiltration or ion exchange unit). This effectively separates or removes chlorides from the purge stream and enables beneficial chemicals to be recycled and used in the wood pulping process.