Multieffect Or Multistage Patents (Class 159/DIG8)
  • Patent number: 6132555
    Abstract: A method and arrangement for increasing evaporation capacity in a multi-stage evaporation plant of spent liquor of a pulp mill. The method includes increasing the pressure of vapor discharged from an evaporation stage by a separate booster, and supplying the vapor having increased pressure to the following evaporation stage. In the arrangement the booster (A-E) is provided in a conduit through which vapor is supplied from one evaporation stage onwards for increasing the pressure of the vapor conducted in the conduit.
    Type: Grant
    Filed: October 30, 1997
    Date of Patent: October 17, 2000
    Assignee: Kvaerner Pulping Oy
    Inventors: Jouko Rikkinen, Tuomo Pokki
  • Patent number: 6106673
    Abstract: A process and system are provided for the separation of a fermentation process byproduct into its constituent components and for the subsequent recovery of those constituent components. The process is remarkably simple--requiring only 1) heating of a mixture containing the byproduct so as to separate the oil from a base component of the byproduct to which the oil is bound, followed by 2) recovering the base product, oil, and possibly other substances such as molasses from the mixture. The process can be performed on a large scale and in a continuous fashion using a mechanical separator to recover fibers from a heated mixture to produce a solids stream and a liquor stream and by then removing oil and insoluble substances from the liquor stream in an evaporator assembly.
    Type: Grant
    Filed: January 8, 1998
    Date of Patent: August 22, 2000
    Assignee: CDC Environmental Corp.
    Inventor: David Ray Walker
  • Patent number: 6090240
    Abstract: A method of inhibiting calcium carbonate scaling in a multi-stage evaporation plant of black liquor by heat-treating calcium-containing liquor includes a first stage wherein the calcium-containing liquor is heated to about 110-145.degree. C. with direct contact with the heating medium; a second stage wherein the liquor is maintained at this temperature in a retention tank for 1-20 minutes to reduce the amount of calcium in the liquor by precipitating calcium carbonate; and a third stage wherein the heat-treated liquor is evaporated for combustion.
    Type: Grant
    Filed: February 20, 1998
    Date of Patent: July 18, 2000
    Assignee: Ahlstrom Machinery Oy
    Inventors: Henrik Eneberg, Jarmo Kaila, Erkki Kiiskila
  • Patent number: 6022453
    Abstract: A compact apparatus of the distillation of solvent from a mixture of the solvent with oil seed for the extraction thereof according to the invention, the primary module includes a vapor scrubber forming a vapor contactor, a main evaporator and a first condenser while the secondary module has an after evaporator combined in a unit with the stripping column and the second condenser.
    Type: Grant
    Filed: August 6, 1998
    Date of Patent: February 8, 2000
    Assignee: Fried. Krupp AG Hoesch Krupp
    Inventor: Klaus Weber
  • Patent number: 5968312
    Abstract: A method and apparatus for forming an array of multiple parallel flow orifices, for example by holes drilled through a plate in a selected pattern and spacing and of selected sizes or flow diameters, and whereby these orifices are used to provide an approximately equal and adequate distribution of liquid flowing through them as parallel streams of liquid and into an evaporation zone or a parallel array of evaporation channels, and wherein the orifices can be adjusted in flow diameter to control the flowrate of liquid in generally parallel streams with an array of orifice adjusting apparatus, for example an adjacent sliding orifice plate which provides for orifice flow rate adjustment with orifices through this second plate corresponding in position to those of the first orifice plate, and the use of such dual orifice plates for supporting a pool of liquid there-above and for controlling the flowrate of liquid through the first array of orifices by reducing or enlarging their orifice flow diameters to control
    Type: Grant
    Filed: June 23, 1997
    Date of Patent: October 19, 1999
    Inventor: Hugo H. Sephton
  • Patent number: 5944950
    Abstract: The process for the final evaporation has at least two evaporation appliances. These appliances are coupled in series with respect to the black liquor and in parallel with the live steam (primary steam), which drives the evaporation, and with the secondary steam that is generated by the evaporation. The pressure of the primary steam that is supplied to the appliance(s) where the liquor concentration is at the highest concentration is greater than the pressure of the primary steam supplied to the other appliances where the liquor concentration is not so high.
    Type: Grant
    Filed: June 27, 1997
    Date of Patent: August 31, 1999
    Assignee: Kvaerner Pulping AB
    Inventors: Lars Olausson, Olle Wennberg
  • Patent number: 5925223
    Abstract: A process and apparatus for improving the thermal efficiency of a steam turbine power generating plant while simultaneously desalinating seawater or brine and purifying water which contains minerals, salts, and other dissolved solids. Exhaust gases from a power plant is heat exchanged against water in a secondary ecomomizer which circulates water at a temperature near, or slightly above the dewpoint of the combustion exhaust of the high-pressure boiler. The heated water is flashed to produce low-pressure steam. The low-pressure steam is condensed against the last effect of a multi-effect desalinization unit. Steam from the first effect of the desalination unit is condensed against steam condensate from the power plant turbine to preheat the condensate and thereby recover heat from the power plant's exhaust gas. Salinous water is fed to the multi-effect desalinization unit to produce fresh water and a concentrated brine.
    Type: Grant
    Filed: April 1, 1997
    Date of Patent: July 20, 1999
    Inventors: Gary D. Simpson, Karl Lin
  • Patent number: 5853549
    Abstract: A large and economical type of multi-stack vertical tube evaporator (MS-VTE) having units of multiple stacks of vertical tube bundles or stages mounted in a single vessel, and having its liquid feed pumped to the uppermost VTE bundle stack or stage and having the feed then cascading downward through the lower bundle stacks in series flow, and wherein all the tube bundles are heated with the same waste steam of no or low $-value, e. g. with turbine reject steam in parallel flow under vacuum into the steam-sides of all tube bundles in the unit through a common steam conduit; and wherein the feed liquid is progressively evaporated from stage to stage or stack to stack and the vapors produced in the tubes of each bundle during the partial evaporation of the feed are separated between the stacks and condensed by parallel flow into one or more condensers.
    Type: Grant
    Filed: October 4, 1996
    Date of Patent: December 29, 1998
    Inventor: Hugo H. Sephton
  • Patent number: 5849148
    Abstract: An evaporator system including a plurality of effects arranged in series for progressively concentrating a liquid, the effects each including: a header chamber for receiving liquid to be concentrated; a multiplicity of tubes adapted to provide evaporation of liquid from the inner surfaces of the tubes and a perforated distributor plate located in the header chamber to distribute liquid to the openings of the tubes; and wherein the evaporator system is provided with a branched wash liquid feed line for providing parallel feeding of wash liquid to the header chambers of the effects onto the distributor plates therein. Each distributor plate comprises an essentially planar plate member having a multiplicity of distributor holes therein for distributing liquid to be evaporated to the multiplicity of tubes therebelow and a series of overflow conduits for providing a flow of wash liquid through the plate to the tubes.
    Type: Grant
    Filed: February 9, 1996
    Date of Patent: December 15, 1998
    Assignee: Ancon Chemical Pty. Ltd.
    Inventor: Michael L. G. Walker
  • Patent number: 5755924
    Abstract: An apparatus, e.g. centrifugal evaporator, has at least one rotary treatment surface, e.g. a heated evaporating surface, which rises outwards from the rotation axis, a liquid feed in the vicinity of the lowest point of the treatment surface close to the rotation axis and a product removal on the periphery of the treatment surface. Such an apparatus is characterized in that the treatment surface over at least part of its axial length has a stepped construction and each step has a step angle of approximately 90.degree.. Thus, as desired, a laminar or turbulent flow is possible. Through the construction of the steps it is possible to widely vary the nature of the flow and consequently the heat and material exchange, as well as the residence time of the liquid.
    Type: Grant
    Filed: August 23, 1996
    Date of Patent: May 26, 1998
    Inventor: Vaclav Feres
  • Patent number: 5730836
    Abstract: A method for concentrating a clay slurry by subjecting the slurry to indirect heat exchange within a heat exchanger to elevate the temperature of the slurry while specifically suppressing boiling of the liquid within the heat exchanger. The heated slurry is subsequently subjected to a rapid pressure reduction which causes flash evaporation of part of the liquid. The rapid pressure reduction can occur in a separation vessel.
    Type: Grant
    Filed: September 26, 1994
    Date of Patent: March 24, 1998
    Assignee: Comalco Aluminium Limited
    Inventors: Christopher Roy Greig, Peter James Tait, Peter John Noble
  • Patent number: 5582690
    Abstract: Desalination of sea water is achieved using a solar pond that includes a halocline interposed between a convective upper wind mixed layer exposed to the ambient atmosphere, and a lower heat storage layer of hot, concentrated brine, Hot brine from the heat storage layer is flashed into steam which is condensed into desalted water using an indirect heat exchanger cooled by saline water. The latent heat of condensation of the steam warms the saline water and effects evaporation of water therefrom in the form of vapor. The last mentioned water vapor is condensed into desalted water using a two-stage condenser, the first stage of which is an indirect heat exchanger cooled by saline feed water which is heated as a result producing warmed saline feed water that constitutes the saline water used for condensing the steam produced by flashing the brine from the heat storage layer of the pond.
    Type: Grant
    Filed: January 21, 1993
    Date of Patent: December 10, 1996
    Assignee: Ormat Turbines (1965) Ltd.
    Inventors: Joseph Weinberger, Uriyel Fisher, Gad Assaf, Benjamin Doron
  • Patent number: 5538593
    Abstract: A thin film flow-down type concentrating apparatus for concentrating a heat susceptible raw liquid with heated steam to high concentration without spoiling the flavor or deteriorating the quality by alternately laminating raw liquid plates and steam plates 20, in which the width of the raw liquid heating passage 18 is gradually narrowed from the raw liquid inlet to the concentrate outlet. As a result, if the volume of the raw liquid decreases due to evaporation and separation of the moisture in the raw liquid, scorching is prevented. Besides, by the steam generated from the raw liquid, in order to prevent increase of the flow velocity of the concentrate going toward the concentrate exit, the plate intervals of the raw liquid heating passage is gradually widened from the raw liquid inlet toward the concentrate outlet.
    Type: Grant
    Filed: February 9, 1993
    Date of Patent: July 23, 1996
    Assignee: Hisaka Works Limited
    Inventors: Yoshiharu Sakai, Kenzo Masutani
  • Patent number: 5480512
    Abstract: To decrease the sulfur emissions of a sulfate pulp mill, and achieve other advantages, black liquor is heated at a temperature higher than the cooking temperature of the sulfate cook (e.g. between 190.degree. C.-350.degree. C.) and the sulfidity of white liquor produced from the black liquor is adjusted by adjusting the temperature and/or retention time of the heat treatment so that a predetermined amount of sulfur compounds are separated from the black liquor. Pressure heat treatment may occur prior to or after evaporation of the black liquor, or between evaporation stages. Preferably, the sulfur containing gas is thereafter divided into different fractions which are separately cornbusted.
    Type: Grant
    Filed: December 27, 1993
    Date of Patent: January 2, 1996
    Assignee: A. Ahlstrom Corporation
    Inventor: Krister Sannholm
  • Patent number: 5423952
    Abstract: A concatenable module for a multiple-effect still has a chamber encompassed by four walls and two baffles, where one baffle is shared with the preceeding effect and the other the subsequent effect. Heat exchanger tubes mount into an accumulator which is sealed to a baffle, an aperature in the baffle at the accumulator allows vapors and fluids to flow between modules.A distribution plug seals the top end of a heat exchanger tube while carrying distilland through internal channels until it reaches a ring channel which carries distilland in evenly around the plug. A gap below the ring channel between the plug and tube allow distilland to flow evenly on the tube as it leaves the plug.
    Type: Grant
    Filed: July 22, 1992
    Date of Patent: June 13, 1995
    Assignee: T & G Technologies, Inc.
    Inventor: Timothy R. Stout
  • Patent number: 5413674
    Abstract: A black liquor process for paper pulping uses a nucleic boiling surface in a series of multi-effective evaporators. The nucleic boiling surface may be used to retube all effects or a single effect.
    Type: Grant
    Filed: December 23, 1992
    Date of Patent: May 9, 1995
    Assignee: UOP
    Inventor: Elias G. Ragi
  • Patent number: 5395483
    Abstract: A distillation apparatus by flashing and boiling of solution and condensing the resulting steam having a central rotating partitioned brine conduit with coupling to a two-disk centrifugal distributor and a wiping blade system in a chamber having at least one conically shaped wall heated by a condensing steam in a spirally formed conduit, and a surrounding annular spiral condenser. The vertical stacking of such conically shaped evaporators and annular spiral condensers with brine inflow and outflow through a central rotating partitioned tubular conduit make up the desalination tower. The solution flowing through the central tubular conduit to the centrifugal distributor is pressurized by the centrifugal force before flashing through spray nozzles. The flowing liquid film formed on the heated conical surface boils with further enhancement from thinning action due to a rotating wiping pivoting blade system.
    Type: Grant
    Filed: July 31, 1992
    Date of Patent: March 7, 1995
    Inventor: Osamah M. Al-Hawaj
  • Patent number: 5382321
    Abstract: A process and apparatus provide for the evaporation of spent liquors in several stages, and recovery of volatile substances from spent liquors of organic solvent pulping processes. The recovery system for volatiles is integrated with the evaporation of spent liquors. Heating condensation is carried out in each evaporator effect on several heat surfaces separated from each other. Pure water, vapor condensate, or steam may be injected to the warmer side of an evaporator effect in order to increase the condensing temperature of the vapor. The volatiles are typically alcohols (methanol and/or ethanol) used as the cooking liquor in organic solvent pulping.
    Type: Grant
    Filed: April 15, 1992
    Date of Patent: January 17, 1995
    Assignee: A. Ahlstrom Corporation
    Inventors: Olof Fagerlind, Erik Agren
  • Patent number: 5380402
    Abstract: A pulp mill has zero or minimum liquid discharges. The large amounts of liquid that must be processed to achieve this result are handled utilizing a multiple effect evaporator provided with heat from a steam exhaust of a condensing type steam turbine. Super heated steam from the recovery and bark boilers is fed to the turbine to generate electricity for the production of bleaching chemical and other uses in the mill. Three or four steam exhausts having different composite temperature and pressure values are taken from the turbine and used where most suitable in the pulp mill. For evaporation of bleach plant effluent the steam taken from the turbine preferably has a pressure of about 1-3 psia and a temperature of about 120.degree.-140 .degree. F, and has no significant adverse affect on power generation.
    Type: Grant
    Filed: October 13, 1992
    Date of Patent: January 10, 1995
    Assignee: Kamyr, Inc.
    Inventors: Rolf Ryham, Tuomo S. Nykanen, Brian F. Greenwood, Johan Gullichsen, Erkki Kiiskila, Esko Mattelmaki, Joseph R. Phillips, Jan Richardsen, Jarmo Soderman, Karl G. Wiklund
  • Patent number: 5366716
    Abstract: Sulphur dioxide is separated from the flue gases of a cellulose pulp mill by absorbing it into a sodium sulphite solution. Sulphur dioxide is regenerated from the sodium bisulphite solution produced by an evaporation-crystallization method utilizing thermo-compressor evaporation technique. A lamella evaporator is utilized as the evaporator-crystallizer, the evaporator being divided into separate compartments for ease of cleaning the lamella surfaces. The recovered concentrated sulphur dioxide can be used wherever desired, for example for the production of chlorine dioxide.
    Type: Grant
    Filed: November 30, 1992
    Date of Patent: November 22, 1994
    Assignee: A. Ahlstrom Corporation
    Inventor: Esko Mattelmaki
  • Patent number: 5360513
    Abstract: Black liquor from a cellulose pulp processing plant is treated, including by using a direct contact (cascade) evaporator, without need for oxidizing the black liquor, without substantial sulphur emissions at the cascade evaporator, and by maximizing the solids content of the black liquor so that the loss of heating value of the black liquor is minimized. The black liquor is heated under temperature and time conditions sufficient to drive off most of the organic sulphur compounds as off gases, which gases are converted primarily to methane and hydrogen sulfide, with the methane separated by selective absorption in white liquor. The black liquor is then stripped of most remaining sulfur by bringing it into stripping contact with flue gases from the recovery boiler, the flue gases taken from downstream of the direct contact evaporator.
    Type: Grant
    Filed: February 13, 1992
    Date of Patent: November 1, 1994
    Assignee: A. Ahlstrom Corporation
    Inventor: Rolf C. Ryham
  • Patent number: 5330618
    Abstract: A process and system for treating aluminum salt cake containing water soluble halide salts by contacting the salt cake with water to dissolve water soluble halide salts forming a saturated brine solution. Transporting a portion of about 25% of the saturated brine solution to a reactor and introducing into the saturated brine solution at least an equal volume of a water-miscible low-boiling organic material such as acetone to precipitate a portion of the dissolved halide salts forming a three-phase mixture of an aqueous-organic-salt solution phase and a precipitated salt phase and an organic rich phase. The precipitated salt phase is separated from the other phases and the organic rich phase is recycled to the reactor. The remainder of the saturated brine solution is sent to a multiple effect evaporator having a plurality of stages with the last stage thereof producing low grade steam which is used to boil off the organic portion of the solution which is recycled.
    Type: Grant
    Filed: December 10, 1992
    Date of Patent: July 19, 1994
    Assignee: University of Chicago
    Inventors: Edward J. Daniels, Bassam J. Jody, Patrick V. Bonsignore
  • Patent number: 5277759
    Abstract: To decrease the sulfur emissions of a sulfate cellulose mill, black liquor is heated before the last effect of the evaporation at a temperature higher than the cooking temperature of the sulfate cook and the sulfidity of white liquor is adjusted by adjusting the temperature and/or retention time of the heat treatment so that a predetermined amount of sulfur compounds are separated from the gaseous black liquor. Preferably, the sulfur containing gas is thereafter divided into different fractions and separately combusted.
    Type: Grant
    Filed: November 16, 1990
    Date of Patent: January 11, 1994
    Assignee: A. Ahlstrom Corporation
    Inventor: Krister Sannholm
  • Patent number: 5275701
    Abstract: A process for the purification and concentration of sulfuric acid contained with nitric acid by-products and organic components pursuant to the mixed acid nitration of aromatics.
    Type: Grant
    Filed: March 15, 1993
    Date of Patent: January 4, 1994
    Assignee: Air Products and Chemicals, Inc.
    Inventors: William J. Mazzafro, Stephen I. Clarke, Philip N. Taylor
  • Patent number: 5256251
    Abstract: A continuous evaporation process for drying water-wet waste solids and sludges, using a paraffin oil solvent, until the waste is dried to a near-zero wastewater product, without experiencing sticky solids. The invention involves (1) mixing the input solids or sludges with a paraffin oil solvent, (2) feeding the mixture into two or more stages of evaporation in parallel to evaporate some of the water present in the input solids or sludges and to extract some of the indigenous solvent-soluble compounds from the solids, (3) feeding the slurry from the parallel stages of evaporation to one or more final evaporation stages in series, and (4) feeding the slurry from the final stages of evaporation to a centrifuge or other device for separating most of the solvent from the solids.
    Type: Grant
    Filed: June 10, 1991
    Date of Patent: October 26, 1993
    Assignee: Hanover Research
    Inventor: Thomas C. Holcombe
  • Patent number: 5209828
    Abstract: A system and method of concentrating spent caustic at a refinery has a multi-stage flash drum for separating a spent caustic stream into an overhead output stream including vaporized water and volatile organic compounds, and a concentrated spent caustic output stream. The system also has a condenser for condensing the overhead output stream, and a separator for separating the condensed overhead output stream into a volatile organic compound stream, a liquid hydrocarbon stream and a water stream. The system further has an ejector for applying a vacuum to the flash drum to vaporize the spent caustic stream at a reduced temperature, and to the separator to remove the volatile organic compound stream. The volatile organic compounds are removed from the overhead of the separator through the ejector to a burner of a fired heater.
    Type: Grant
    Filed: December 23, 1991
    Date of Patent: May 11, 1993
    Assignee: Mobil Oil Corporation
    Inventors: Tai-Sheng Chou, Manuel Gonzalez
  • Patent number: 5188857
    Abstract: A citrus juice concentrate processing homogenizes a mixture of citrus juice and pulp within or after a multi-effect, multi-stage evaporator. The homogenizer employs a positive displacement pump for pumping the citrus juice mixture through an orifice with a high pressure differential across the orifice. The homogenizer reduces viscosity of the citrus juice mixture. Inter-stage placement of the homogenizer further enables final citrus juice concentrate Brix levels of 72.degree. Brix and greater to be achieved.
    Type: Grant
    Filed: January 2, 1991
    Date of Patent: February 23, 1993
    Assignee: APV Gaulin, Inc.
    Inventor: Philip M. Grant
  • Patent number: 5156706
    Abstract: A vertical tube evaporation process for the concentration of saline water and other liquids, including the addition of an anionic mono-molecular dispersant thereto which interacts with materials precipitated during concentration and inhibits the formation of scale or fouling depositions on evaporator surfaces, and wherein the additive is incorporated into the precipitated materials and improves their removal during the descaling or defouling of evaporator surfaces by rendering such precipitates redispersable in fresh water or in a non-saturated liquid used for descaling or defouling of evaporator surfaces.
    Type: Grant
    Filed: April 29, 1988
    Date of Patent: October 20, 1992
    Inventor: Hugo H. Sephton
  • Patent number: 4986884
    Abstract: A process for the production of monomeric .alpha.-cyanoacrylates by pryrolysis of poly-.alpha.-cyanoacrylates and subsequent distillation of the resulting monomeric .alpha.-cyanoacrylates.
    Type: Grant
    Filed: October 28, 1987
    Date of Patent: January 22, 1991
    Assignee: Bayer Aktiengesellschaft
    Inventors: Wolfgang Arlt, Helmut Waniczek, Richard Viard, Dieter Bruck
  • Patent number: 4981555
    Abstract: The solutions are concentrated by multiple-effect evaporation in indirectly heated evaporators. The highest concentration of the solution is reached in a final evaporator stage, which is heated with live steam. The final evaporators stage includes two to four falling-film evaporators, all of which are heated with live steam. The falling-film evaporators are consecutively flown through by the solution. Vapor is withdrawn from that falling-film evaporator which is the first to be supplied with the solution and at least part of said vapor is directly contacted with the solution as it flows down through the heating zone of at least one other evaporator of the final stage. From that falling-film evaporator of the final stage which is the first to be supplied with the solution the vapor may be fed to all other evaporators of the final stage.
    Type: Grant
    Filed: September 21, 1989
    Date of Patent: January 1, 1991
    Assignee: Metallgesellschaft AG
    Inventors: Klaus Hohmann, Manfred Mai
  • Patent number: 4953607
    Abstract: A thermal system includes a plurality of heat exchangers in series and the same number of flash tanks in series is interposed between two subsequent effects of a multiple effect evaporating system for sulfate black liquor. The liquor is indirectly heated in the heat exchangers by vapor produced by step-by-step expansion of the same liquor in the flash tanks and additionally by steam from an external source. To decrease the viscosity of the black liquor it is heated to a temperature of 190.degree.-200.degree. C. and retained in a reactor vessel for 10-20 minutes.Preferably the flash tanks and the heat exchange elements are positioned on top of each other within a shell to form an integral construction in which the vapor compartment of each flash tank is directly connected to the vapor compartment of a corresponding one of the heat exchange elements.
    Type: Grant
    Filed: June 14, 1989
    Date of Patent: September 4, 1990
    Assignee: A. Ahlstrom
    Inventors: Kiiskila Erkki, Ryham Rolf
  • Patent number: 4946559
    Abstract: A method and device for removing, from liquid such as water, dissolved volatile substances and gases when water is being distilled or evaporated. Feed water of a distilling apparatus or evaporator is heated to a sufficiently high temperature, whereby part of the feed water changes into vapor, and is then conducted to a purifying device. The feed water is discharged in the purifying device in the form of a thin film. The gaseous substances present in the feed water or liquid are separated by a separator device provided in the purifying device, and then conducted away through a connector provided on the purifying device.
    Type: Grant
    Filed: November 3, 1988
    Date of Patent: August 7, 1990
    Assignee: Oy Santasalo-Sohlberg AB
    Inventors: Rolf Kroneld, Markku Reunanen, Esko Huhta-Koivisto
  • Patent number: 4944839
    Abstract: A falling film evaporator in which some plate elements have their upper portions surrounded by a hood to prevent feed liquor from contacting hot vapor generated in the evaporator and exchanging heat therewith by direct contact. Other elements are located outside the hood.
    Type: Grant
    Filed: May 30, 1989
    Date of Patent: July 31, 1990
    Assignee: Rosenblad Corporation
    Inventor: Axel E. Rosenblad
  • Patent number: 4929307
    Abstract: A method of decreasing the viscosity and improving the evaporability of sulfate black liquor from the cellulose cook includes raising the temperature of the black liquor above the cooking temperature so as to split the macro-molecular lignin fraction contained in the liquor. The temperature of the black liquor is maintained at the raised level for 1 to 60 minutes, preferably for 1 to 5 minutes.
    Type: Grant
    Filed: February 17, 1989
    Date of Patent: May 29, 1990
    Assignee: A. Ahlstrom Corporation
    Inventors: Erkki J. Kiiskila, Nils E. Virkola
  • Patent number: 4838998
    Abstract: The amount of water required to effect efficient separation of a mixture of sulfuric acid and carboxylic acids by distillation, is reduced, by diluting the mixture while in the distillation column in a prescribed manner with sufficient water to provide a water:sulfuric acid mole ratio of about 1:1. The heat generated by the internal dilution reduces the energy requirement of the column. Feeding the dilution water to the column below the feed mixture is a key element of the process.
    Type: Grant
    Filed: December 4, 1987
    Date of Patent: June 13, 1989
    Assignee: Rohm and Haas Company
    Inventors: Philip D. T. Davies, Lawrence S. Kirch
  • Patent number: 4814021
    Abstract: A method for cleaning and reclassifying electrical apparatus designed for use with PCB fluid electrolytes is described which is capable of operation on the site of the equipment being cleaned and while said equipment is energized.
    Type: Grant
    Filed: July 27, 1987
    Date of Patent: March 21, 1989
    Assignee: ENSR Corporation
    Inventors: Michael J. Massey, David R. Hopper
  • Patent number: 4789428
    Abstract: The invention relates to a method for evaporation of spent liquor by heat from a blow condenser where blow steam from a pulp cooker is condensed in a direct condenser connected with a hot water accumulator. Spent liquor heated indirectly by hot water from the accumulator is brought to expand and released expansion vapor is used as a heat medium in a following evaporation stage. The apparatus comprises a heat exchanger, at least one flash tank and at least one evaporation unit, the heat exchanger being disposed to receive hot water from the upper part of the accumulator and to return it to its lower part and thus heat the spent liquor, and the flash tank being disposed to receive spent liquor heated in the heat exchanger and to release liquor vapor and spent liquor to the evaporation unit.
    Type: Grant
    Filed: June 3, 1986
    Date of Patent: December 6, 1988
    Assignee: Ahlstromforetagen Svenska AB
    Inventor: Rolf Ryham
  • Patent number: 4767502
    Abstract: A steam generator, especially a pure steam generator, having a feed line for conducting feed water to the same, an electrode system for heating the feed water, a steam outlet for removing generated steam, and a separating space in a lower part of the generator 10, along with a droplet separator through which the steam that has been generated is disposed to flow from the separating space to the steam outlet. Electrodes have been placed in small tubular spaces in a water space (i.e. a space receiving incoming feed water). The steam generator may be used in a multi-stage distilling apparatus by conducting the steam that has been formed to a second column or stage of the distilling apparatus, to constitute feed steam therefor.
    Type: Grant
    Filed: May 20, 1987
    Date of Patent: August 30, 1988
    Assignee: Oy Santasalo-Sohlberg AB
    Inventors: Lauri Santasalo, Esko Santasalo
  • Patent number: 4756797
    Abstract: A multiple effect evaporator system and a process for concentrating a process liquid wherein evaporated process liquid from one effect serves as heating fluid in an adjacent effect. Low energy heating fluid in vapor form is fed to an evaporative surface condenser where it is condensed and collected as clean and foul condensate. Coolant for the evaporative surface condenser is provided in the form of process liquid from one of the effects. Prior to passage into the evaporative surface condenser, the process liquid is cooled. In the cooling circuit of the evaporative surface condenser, the process liquid absorbs the heat of condensation of the heating fluid and subsequently rejects the heat into a counter flowing air stream. The process liquid is thereafter heated and returned to another of the multiple evaporator effects.
    Type: Grant
    Filed: October 20, 1986
    Date of Patent: July 12, 1988
    Assignee: Kamyr, Inc.
    Inventors: Carl Elmore, Timothy Carter
  • Patent number: 4755258
    Abstract: Calcium containing sulphate spent liquor is deactivated by means of heating. Spent liquor is heated by means of direct condensing in a flash-steam-system. Liquor vapors generated during expansion of the already deactivated spent liquor are used for heating the spent liquor. Spent liquor is led to a retention tank through n+1 in series connected direct condensers (DK I-DK V) and from the retention tank through n in series connected flash tanks (FT I-FT IV) disposed counter-currently to the direct condensers. In the last one of the direct condensers (DK V) the liquor is heated by means of externally supplied steam; in all others (DK I-DK IV) by means of expansion vapor.
    Type: Grant
    Filed: May 29, 1986
    Date of Patent: July 5, 1988
    Assignee: Ahlstromforetagen Svenska AB
    Inventor: Rolf Ryham
  • Patent number: 4731164
    Abstract: A multi-flash evaporator having modular vertical cyclone chambers designed to generate a paraboloid of revolution providing an extended surface area for release of flashed vapors and attaining equilibrium. With multiple stages, the system incorporates deep loop seals to prevent blowby between stages at all levels of capacity and employs a vapor lift system to permit low pressure differentials between stages at high vacuum. The cyclone chambers employ an intermediate tangential inlet whereby the flashing vapors propel the liquid at higher velocities to generate a deeper paraboloid of revolution and centrifugally separate the heavier liquid from the flashing vapor. An anti-creep ring is interdisposed at the top of the cyclone to prevent the liquid from entering a mesh so only vapor impinges on the mesh and passes to the heat recovery condensers embodying a bayonet augmented tube heat exchanger.
    Type: Grant
    Filed: May 10, 1985
    Date of Patent: March 15, 1988
    Inventor: William R. Williamsom
  • Patent number: 4707220
    Abstract: A thin film evaporator consists of an enclosure defining a vapor space, a level drive shaft running into the enclosure and a rotor fixed to the shaft and having an axis of rotation disposed horizontally when in operative position, the rotor being made up of spaced coaxial conical evaporator elements, whose evaporation space communicates with the vapor space. The feed to be evaporated is supplied at one end of the rotor at the inner circumference of one or more conical evaporator elements thereof. Such evaporator elements are placed together in pairs so that they taper outwards with the evaporating faces thereof facing each other, so as to form a collection trough at their outer edges for the concentrate. The feed spreads out in the form of a film from the inner edge or edges for the elements and is taken up in the respective collection trough as a preconcentrate.
    Type: Grant
    Filed: March 14, 1986
    Date of Patent: November 17, 1987
    Inventor: Vaclav Feres
  • Patent number: 4695349
    Abstract: A process is disclosed for distillation and/or stripping in a column, the lower portion of which is heated and the upper portion of which is cooled. The heating and cooling facilities thereof are coupled with each other by means of a heat pump system. In order to reduce the energy input, the invention provides for driving the heat pump system by means of expansion of a gas or vapor, and with the gas or vapor, after expansion, utilized as the stripping gas in the column.
    Type: Grant
    Filed: March 7, 1985
    Date of Patent: September 22, 1987
    Assignee: Linde Aktiengesellschaft
    Inventors: Hans Becker, Gerhard Linde
  • Patent number: 4661208
    Abstract: The invention provides a means for greatly saving the thermal energy consumption in the dehydrating distillation of an aqueous solution of a carboxylic acid such as acetic acid by use of an azeotropically distilling entrainer boiling at a lower temperature than the carboxylic acid and immiscible with water. The improvement proposed by the invention comprises taking at least a part of the entrainer phase separated from the condensate coming from the column top or at least a part of the side-cut fluid abstracted from the refluxing fluid inside the column, evaporating the thus taken fluid into vapor and introducing the vapor into the distillation column at a stage for the introduction of the starting feed or below.
    Type: Grant
    Filed: June 21, 1985
    Date of Patent: April 28, 1987
    Assignee: Shin-Etsu Vinyl Acetate Co., Ltd.
    Inventors: Yoshihiro Honma, Fumiaki Kawamoto, Shozo Tanaka
  • Patent number: 4636283
    Abstract: In the distillation of fresh water from sea water, the sea water is passed ownwardly in a falling film evaporator through a multiplicity of vertical tube evaporator (VTE) stages and multiple stage flash (MSF) evaporators. After the sea water passes through the first VTE stage where it forms a liquid component and a steam component, the liquid component is distributed evenly into the next VTE stage while the steam component enters an adjoining MSF stage. Condensed fresh water flows downwardly from one MSF stage to the next and experiences flash evaporation. The sea water or brine component and the fresh water distillate flow downwardly through the VTE and MSF stages so that the brine component can be removed from the final VTE stage and the fresh water distillate from the final MSF stage.
    Type: Grant
    Filed: March 6, 1984
    Date of Patent: January 13, 1987
    Assignee: D.V.T. Buro fur Anwendung Deutscher Verfahrenstechnik H. Morsy
    Inventor: Gamal E. D. Nasser
  • Patent number: 4624747
    Abstract: In the distillation of fresh water from sea water, the sea water is passed ownwardly in a falling film evaporator through a multiplicity of vertical tube evaporator (VTE) stages and multiple stage flash (MSF) evaporators. After the sea water passes through the first VTE stage where it forms a liquid component and a steam component, the liquid component is distributed evenly into the next VTE stage while the steam component enters an adjoining MSF stage. Condensed fresh water flows downwardly from one MSF stage to the next and experiences flash evaporation. The sea water or brine component and the fresh water distillate flow downwardly through the VTE and MSF stages so that the brine component can be removed from the final VTE stage and the fresh water distillate from the final MSF stage.
    Type: Grant
    Filed: October 9, 1985
    Date of Patent: November 25, 1986
    Assignee: D.V.T. Buro fur Anwendung Deutscher Verfahrenstechnik H. Morsy
    Inventor: Gamal el Din Nasser
  • Patent number: 4597835
    Abstract: A still comprises a housing, a hollow rotor rotatably mounted in the housing and having one or more outlets for liquid at the periphery thereof, means for rotating the rotor about its axis, a plurality of concentric lamellar bodies of thermally conductive material mounted in the hollow interior of said rotor so as to provide a labyrinthine path within the rotor for liquid moving radially outwardly under centrifugal force and for vapor moving radially inwardly with respect to the rotor, vaporizing means for vaporizing liquid to be distilled, liquid inlet means for introducing liquid to a radially inner part of the hollow interior of said rotor, vapor outlet means communicating with a radially inner part of the hollow interior of said rotor, and liquid outlet means for removal of liquid from the housing, whereby in use vapor is constrained to move radially inwardly and liquid to move radially outwardly under centrifugal force within said rotor, fractionation occurring at least in part by condensation of vapor o
    Type: Grant
    Filed: November 28, 1984
    Date of Patent: July 1, 1986
    Inventor: John Moss
  • Patent number: 4568353
    Abstract: In a process of producing coarse pure potassium chloride crystals from feed solutions containing potassium chloride and other impurities, comprising cooling the solution under a vacuum in a plurality of stages connected in series, withdrawing by means of a conveyor the potassium chloride which has been crystallized in each stage, withdrawing the water vapors, collecting crystalline potassium chloride from the solution, drying the crystalline potassium chloride and separating the same into several fractions, compacting the fine fraction and cooling and aminating the end product, the potassium chloride content of the feed solution is increased in that potassium chloride from one or more of the stages containing solution at a low temperature is recycled to the feed solution before the latter enters the first stage.
    Type: Grant
    Filed: March 4, 1983
    Date of Patent: February 4, 1986
    Assignee: Metallgesellschaft Aktiengesellschaft
    Inventors: Horst Hartmann, Manfred Beckmann, Walter Bauer
  • Patent number: 4534800
    Abstract: In a process for the production of sugar thick juice from lime-containing raw juice and wherein carbon dioxide and soda are added to the lime-containing raw juice in at least one carbonation step, and wherein the thin juice is preheated and evaporated to form thick juice, ammonia in the form of gaseous spent heating medium originating from the preheating of the thin juice is added to the lime-containing raw juice. The method of the invention results in a reduction of the consumption of soda in the carbonation step and in an increased sugar yield.
    Type: Grant
    Filed: November 23, 1983
    Date of Patent: August 13, 1985
    Assignee: Aktieselskabet de Danske Sukkerfabrikker
    Inventor: Bjarne Winstrom-Olsen
  • Patent number: 4514260
    Abstract: Apparatus for a vertically extending heat exchanger column for the desaliion of sea water based on a multi-effect evaporation process includes a container for forming a pressure-tight enclosure about the heat exchanger column. The container is made up of four upwardly extending side walls, a top end wall and a bottom end wall. The side walls are arranged in pairs with the walls of each pair spaced opposite one another. A truss-like support structure is arranged around the outside of the container with one pair of side walls and the top and bottom end walls fixed to the support structure. The other pair of side walls are movably secured to the support structure. Lifting tackle is located on the upper end of the support structure. Movable platforms are mounted along the movable side walls of the container. Snap closures secure the movable side walls to the other side walls and to the end walls. Seals are provided along the movable side walls for the pressure tight enclosure of the container.
    Type: Grant
    Filed: May 20, 1983
    Date of Patent: April 30, 1985
    Assignee: D.V.T. Buro fur Anwendung Deutscher Verfahrenstechnik H. Morsy
    Inventor: Gamal el Din Nasser