Abstract: An experiment system and method for accurate controlling of macromolecular crystallization process. The system has a platform-equipped horizontal moving slot and channel dedicated backwash module, a droplet adding control module, an observing module, a user observation computer system, and an experimental condition control module. A high-precision movement knob of the x-axis platform and the y-axis platform of the system and the accurate position control of a syringe needle are used to ensure that the macromolecular solution can be added into the correct positions of convex or concave. The crystallization induction period of the target crystal form is determined by the real-time data of the high-speed microcamera, and the crystal cultivation environment is adjusted in real time. This is simple and easy to operate, high in productivity, can be applied to the conventional experimental replication.

Abstract: A process for purifying water via freezing is disclosed. The process may include: contacting an aqueous mixture with a flotation medium, wherein the flotation medium has a density greater than or equal to the density of ice or hydrate and less than the density of the aqueous mixture or concentrated brine at its freezing point; reducing the temperature of the aqueous mixture to a temperature equal to or below the freezing point of the aqueous mixture to form ice or hydrate and a concentrate; phase separating the concentrate and the flotation medium; recovering the concentrate; and recovering the ice or hydrate and flotation medium as a slurry. Upon melting, phase separation of the resultant water from the flotation medium may provide a purified water product.

Abstract: A process for purifying removal of crystals from their suspension in mother liquor by means of a washing column having forced transport in which the process chamber is encased by a metal wall which, on its side facing away from the process chamber, is heated at least along the length of the pure melt zone.

Abstract: A process and apparatus is presented for the desalination of water by freezing seawater. The process is integrated into a liquefied natural gas regasification system.

Abstract: The object of the invention is to provide a method for preparing deep-frozen liquid gas for the purpose of recovering process energy for a downstream process, with which the refrigerating capacity of the deep-frozen liquid gas can also be used in the downstream process. According to the invention, this is achieved by the fact that the refrigerating capacity of the deep-frozen liquid gas (1) is fed as a heat sink to at least one of the part-steps of the downstream process via at least one heat-exchange medium (28, 54, 79) and, if said heat-exchange medium (28, 54, 79) is not available, the deep-frozen liquid gas (1) is regasified with an additional heat-exchange medium (32).

Abstract: A method and apparatus for safely, conveniently, and inexpensively liberating gas from gas hydrates includes the use of a device, provided adjacent to or in the bulk gas hydrates, for exposing the gas hydrates to heat from a gas or liquid (preferably steam). The gas hydrates can be directly exposed to the gas or liquid or indirectly exposed through a thermally conductive coil or channel. The heat from the gas or liquid dissociates the gas hydrates into the corresponding gas component and water component. After liberation, the gas component can be collected for further storage, transport, or use. The apparatus further includes a mechanism for moving at least a portion of the gas or liquid through the device for exposing the gas hydrates to heat. The device for exposing the gas hydrates to heat also can be movable, so it can be maintained in close proximity to or in contact with the gas hydrates for continued efficient gasification of the hydrates.

Abstract: The invention provides a system for unloading liquified gases from rail cars or other transport vehicles by using an energy buffer system which allows the shifting of electric demand to off-peak hours when electric power rates are lower. The system employs a buffer tank containing solidified gas to withdraw vapor remaining in the rail car after the liquified gas has been removed. The invention relies on the fact that the liquified gas which is to be unloaded has a triple point pressure that is low enough to allow recovery of the majority of the residual vapor in the rail car. The system allows the use of a smaller refrigeration unit operating at a constant load over a long period of time, in place of a larger refrigeration unit. The system also provides an additional advantage of extracting vapor from a rail car at a faster rate than the rate which is possible with a typical compressor.

Abstract: In a "permanent" magnet system based on high-temperature superconductors, a superconducting magnet is cooled to a temperature below its critical temperature with a cooler. The magnet is coupled to a cold body of solid nitrogen which is insulated to minimize heat input to the system. The superconducting magnet is energized to generate a magnetic field and the cooler is removed. Unlike conventional superconducting magnets in which the magnet operating temperature is maintained at a fixed point, in the system of the present invention the operating temperature is allowed to rise from an initial value of approximately 20 K to as high as 63 K (the melting point of nitrogen), enabling operation over an extended period without the aid of direct cooling. The superconducting magnet is recooled periodically to lower its temperature to approximately 20 K. The magnetic field is maintained and the system is fully operable during the recooling process.

Abstract: A device for receiving thermal conduit comprising a thermally conductive material for coupling between an end of a conducting element of the thermal conduit and an end of an outer shell of the thermal conduit. The thermally conductive material is arranged to physically define a best thermal path from the end of the conducting element to the end of the outer shell such that substantially all thermal energy dissipated from the conducting element to the outer shell flows along the best thermal path. The length of the best thermal path is significantly greater than a nearest distance between the conducting element and the outer shell, and the conductive material is thin and manufactured of a poor thermal conductor such that the total energy dissipated along the best thermal path is reduced.

Abstract: A cooling apparatus especially for cooling high-temperature-superconducting lectronic components includes a cold gas cooling machine, such as a Stirling machine, thermally connected to a pressure vessel serving as a cold reservoir vessel. The pressure vessel contains a working medium having a triple point in the temperature range from about 60K to about 90K and a critical temperature at least as high as the maximum operating room temperature of the apparatus. The working medium is propane, for example. A cooling surface of the electronic component is thermally connected to the pressure vessel. In the method of operating the apparatus, the electronic component does not require continuous cooling. During a charging or refrigerating phase, the cooling machine freezes the working medium. Then during a useful cooling phase, the cooling machine is switched off and the electronic component is operated while being cooled by the frozen working medium.

Abstract: A system for the storage or shipment of frozen or chilled biological materials consisting of a cryogenically insulated vessel which contains a heat sink material. The heat sink material is initially chilled to a very low temperature to keep the contents of the vessel cold. The heat sink may include a change of phase to provide extension of the possible shipment or storage time at a relatively constant temperature.

Abstract: Device for extracting heat from a hot source (7) and transferring it to an autonomous heat accumulator, which is portable, forming a cold source, this device having the special feature that the said accumulator is formed by an enclosure (1) containing ammonia under conditions such that at least a significant portion of the heat transferred to this accumulator causes the ammonia to pass from the solid state to the liquid state. The device is usable for the thermal control of protective equipment or of leakproof protective suits intended for work in a toxic atmosphere or at high temperature, or also in space.

Abstract: A method of freezing and separation for concentrating solutions, such as waste waters of the process industry, by means of waste heat of the same process, by freezing the solution in a crystallizer operating at the triple point, by transferring the ice crystals produced thereby into a melter, by absorbing the cold vapor generated in the crystallizer into an absorber of a first absorption heat pump, said absorber being cooled by cooling water, by evaporating a corresponding amount of vapor in a generator of the absorption heat pump, said generator being heated by the waste heat of the process and, by melting the ice crystals by this vapor.

Abstract: An installation for generation of a refrigerated gas flow from a mass of refrigerating material in solid or liquid state, includes a closed vaporization chamber (4) containing a charge (7) of refrigerating material in liquid or solid state and capable of resisting pressure. An ejector (9) of the Venturi type ensures the drive of a much greater gaseous flow rate by a drive stream of gas under pressure. A conduit (12) connecting the closed vaporization chamber (4) to the ejector (9) to feed to this latter the gas from the chamber by vaporization or sublimation of the refrigerating material as a drive flow of gas under pressure. The outlet of the ejector (9) is connected to a sleeve (10) whose length extends through a refrigerating chamber. This sleeve has along its length outlet nozzles (11) to distribute the refrigerated gas flow throughout the volume of the refrigerated chamber and to ensure the agitation of the air in this latter by jets of gas from the nozzles.

Abstract: An apparatus for removing polluted clinging water from ice. The dirty ice pieces are introduced at the bottom of a column of water and are rinsed by progressively cleaner water as the ice pieces float to the surface.

Abstract: The present invention relates to an improved process for the reliquefaction of boil-off gas containing up to 10% nitrogen resulting from the evaporation of liquefied natural gas (LNG) contained in a storage vessel. In the process, a closed-loop nitrogen refrigeration cycle is utilized wherein the nitrogen is isenthalpically expanded under conditions for generating a liquid and vapor with the liquid being pressurized by pumping and warmed against an initially cooled boil-off stream. The boil-off LNG stream is initially cooled by indirect heat exchange with an isentropically expanded refrigerant stream.

Abstract: A new vacuum freezing separation process entitled "Vacuum Freezing Ambient Pressure Melting (VFAPM) Process" and a new apparatus entitled .cent.Sub-Triple Point Vapor Processing Unit" for generating and liquefying a sub-triple point vapor have been introduced. The process is useful in desalination, concentration of industrial solutions, water reuse and pollution abatement. The vapor processing unit can be used in vacuum freezing processes, distillative freezing processes, freeze-drying processes and other processes in which sub-triple point vapors are generated and are to be liquefied.The VFAPM Process is conducted in two processing zones, a vacuum processing zone and an ambient pressure processing zone.

Abstract: An apparatus for purifying crystals comprises a crystal purifying tower having a transverse cross-section of two partially overlapping circles, stirrers each comprising a rotational shaft passing through the center of each of the circles and having blade members disposed spirally on its surface, a solid-liquid separation plate disposed at the bottom portion of the tower, a liquid take out means disposed below the separation plate, a starting crude crystal feed means disposed above the separation plate, a purified crystal take out means disposed at the upper portion of the tower, heating means disposed in the tower in a multistage manner along the longitudinal direction of the tower, and purified crystal circulation means for cooling a portion of purified crystals taken out from the tower and feeding back the cooled crystals to the tower at at least one portion of the tower.

Abstract: An improved crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase of the crystallizable material obtained upon freezing a liquid phase of the materials. The solid phase is more dense than the liquid phase, and it is separated therefrom by relative movement with the formation of a packed bed of solid phase. The packed bed is continuously formed adjacent its lower end and passed from the liquid phase into a countercurrent flow of backwash liquid. The packed bed extends through the level of the backwash liquid to provide a drained bed of solid phase adjacent its upper end which is melted by a condensing vapor.

Abstract: Separation and recovery of dibenzofuran of high purity is accomplished by distilling a coal tar fraction having boiling point range of 220.degree. to 300.degree. C. thereby producing a dibenzofuran fraction having a dibenzofuran content of not less than 30% by weight, a dibenzofuran/acenaphthene molar ratio of not less than 1.3, and a fluorene/dibenzofuran molar ratio of not more than 0.05, then introducing the dibenzofuran fraction obtained as described above into a continuous crystallization purification unit provided with a cooling zone for crystallization of the feed, a heating zone for melting the purified crystals, and a refining zone for enabling crystals being transferred from said cooling zone to said heating zone to come into counter current contact with a mass of molten crystals midway along the path between said two zones, and subjecting the dibenzofuran fraction to continuous crystallization purification therein.

Abstract: A countercurrent, cooling crystallization and purification method for a multi-component molten mixture wherein the mixture is treated by a purification system comprising one or more crystallizers (1A, 1B) each having, at the respective upper portion, a clarifying portion (10A, 10B) and a purifier (2) arranged in series to the crystallizer or crystallizers and having, at its upper portion, a clarifying portion (20), the crystallizer or crystallizers and the purifier having a temperature difference therebetween and disposed in the order of temperature. The starting mixture is fed to one of the crystallizers and subjected to crystallization there, and the resulting crystals are taken out from the bottom of the crystallizer and fed to another crystallizer or a purifier of higher temperature while the clarified liquid, i.e., mother liquor positioned at the clarifying portion of the crystallizer is led to another crystallizer of lower temperature or discharged out of the system.

Abstract: A water purifier for producing potable water from contaminated water, the purifier includes a crystallizer chamber with a plurality of projecting freeze elements, and a water spray unit which directs a fine spray of water at the freeze elements to produce ice coating on the freeze elements. The purifier also includes a refrigerant unit to periodically chill and warm the freeze elements to alternately produce and release ice shells that are melted to form purified water.

Abstract: An improved freeze concentration system of the type in which a slurry of crystals and mother liquor are formed in a crystallizer and fed to the concentrated end of a gradient column. The crystals grow in size in the column as they move to the dilute end of the column. The dilute slurry is transferred to a holding tank where the crystals grow further and then to a wash column. A slurry of larger crystals from the holding tank or the column outlet are fed back to the column inlet so that crystals in the concentrated slurry dissolve and reform on the large crystals of the fed back slurry. The units can be connected in a multistage, counter-current system.

Abstract: Improved apparatuses and methods of operation for conducting the separation process entitled "Vacuum Freezing Multiple Phase Transformation Process (denoted as VFMPT Process)" have been introduced. Processing zones and valving means are properly arranged so that operations in most processing zones are continuous. An improved VFMPT plant can be operated simply and reliably and be constructed at a low cost. Corrosion problems, use of a low pressure compressor, use of an absorbing solution have been eliminated.

Abstract: Process for separating the ice crystals contained in a slurry of an aqueous olution and ice crystals from the aqueous solution and washing the ice crystals with an aqueous wash liquid, whereby a packed bed of ice crystals is created which is subjected to a continuous translatory movement, while a washfront is being created within the packed bed of ice crystals between the aqueous solution and the aqueous wash liquid, the aqueous solution and aqueous wash liquid adjacent to the washfront being substantially stagnant, a stable washfront being created lying in a plane perpendicular to the translatory movement of the packed bed of ice crystals.

Abstract: The present invention introduces a process for effectively washing a crystal-liquid (mother liquor) mixture with a mass of wash liquid to thereby form a mass of highly purified crystals and also introduces apparatuses for use therein. The purification is accomplished by properly conducted alternative stationary and agitated crystal washing operations and substantially countercurrent transfer of the solid phase and the free liquid in a purification zone. The zone contains a set of stationary washing sub-zones and a set of agitated washing sub-zones that are laid alternatively along the vertical direction.The mass of crystals in a stationary sub-zone is compacted by a compacting means to form a bed with an enhanced degree of compaction. The masses of crystals and liquid in each agitated sub-zone are properly agitated so that the impurities in the mother liquors retained in the crystal mass are released to the free liquid.

Abstract: A system and method for concentrating aqueous beverages such as fruit juices, beer, wine, vinegar, tea, coffee, and the like in which a slurry of feed liquid and seed crystals is formed in a scraped surface heat exchanger of a first stage and supplied to a recrystallizer where larger crystals grow, the liquid in the recrystallizer being withdrawn with part recirculated to the heat exchanger of a succeeding stage. The slurry of larger crystals in the recrystallizer of the first stage is also withdrawn and the crystals separated in a wash column. The larger crystals grown in the second stage recrystallizer are supplied to the recrystallizer of the first stage where the seed crystals melt and reform on the larger crystals and the larger crystals from the third stage are similarly supplied to the recrystallizer of the second stage.

Abstract: Provided is a freeze concentration apparatus and method which embody means designed, sized and arranged for inhibiting ice deposition including an enclosed cyclonic concentrator vessel having unobstructed, smooth faced interior walls.

Abstract: A method for separating and purifying a crystallized component from a two-phase slurry of a crystallized component in a liquified multi-component mixture, the method including a purification column capable of withdrawing the crystallized component from the slurry having multi-component mixture therewith, and passing a heated inert gas through the purification column in a direction countercurrent to the withdrawal of the crystallized component to result in a purified residue of crystallized component.

Abstract: A separator particularly useful in freeze concentration systems and apparatus, particularly multi-stage countercurrent systems for concentrating aqueous feed liquid, but useful for other kinds of separators as well. The slurry to be separated enters a vessel in which is mounted and rotated a cylindrical filter. The liquid passes through the filter to one outlet while the solids accumulate on the filter and are removed and directed to another outlet by a fixed scraper.

Abstract: The Vacuum Freezing Vapor Desublimation Desublimate Vaporization Process (denoted as VDDV Process) is an improved vacuum freezing process that is useful in separating solvent from a solution that contains one or more non-volatile solutes. It can be used in desalination of sea water and brackish water, renovation of waste water, and concentration of aqueous and non-aqueous solutions.Referring to sea water desalination, the process comprises the following steps: (a) feed sea water is flash vaporized under a reduced pressure to thereby form a first low pressure water vapor (3.5 torr) and an ice-brine slush; (b) the first low pressure water vapor is cooled without pressurization to form a mass of desublimate; (c) the ice-brine slush is separated into a mass of purified ice and a concentrated brine; (d) the desublimate is melted and vaporized to form a second low pressure water vapor that is at a pressure higher than the triple point pressure of water (4.

Abstract: The invention relates to an apparatus for and method of preparing a slurry for a purification apparatus such as a wash column. A slurry is produced in a crystallizer. The crystals are essentially removed from the concentrated mixture and transported to a more dilute solution. The crystals are caused to dwell in the dilute solution to permit the crystals to ripen and to grow in size significantly.The apparatus that performs the foregoing functions is a gradient column where the change from a concentrated slurry to a dilute slurry takes place. The output of the gradient column is coupled to a holding tank where the residence time of crystals in the dilute solution is prolonged to permit the crystals to ripen.

Abstract: Apparatus comprising a vertical vessel having a lower downwardly pointed conical shell portion, an intermediate shell portion and an upper shell portion wider than the lower and intermediate portions and with all said vessel portions surrounding and defining an unobstructed interior; a conduit for feeding a liquid stream, containing solids less dense than the liquid, tangentially to the vessel intermediate portion interior so that the liquid flows in a helical path therein and then flows downwardly to and in the lower conical portion whereby less dense liquid slurry concentrates in the central area of the lower conical portion and flows upwardly into the vessel upper portion while more dense liquid slurry concentrates in the vessel lower conical portion; a conduit to withdraw more dense liquid slurry from the vessel lower conical portion; and a distributor for directing washing liquid onto the slurry while the slurry is in the vessel upper portion.

Abstract: Freeze concentrating an aqueous liquid mixture by feeding an aqueous liquid mixture to a freeze exchanger for indirect cooling by heat exchange to a cold fluid to form ice crystals in the liquid mixture; feeding the liquid mixture containing ice crystals from the freeze exchanger to the lower internal space of a vessel containing said aqueous liquid mixture whereby the ice floats to the top interior of the vessel; removing ice from the top interior of the vessel, washing the ice with water and heating the washed ice to produce potable water; removing aqueous liquid mixture from the vessel and recycling it to the freeze exchanger; and repeating the method in a continuous operation.

Abstract: Continuous counter current multistage process for freeze concentration, iuding a step whereby the ice crystals in the first stage are separated from the mother liquor in a final separation step, the ice crystals being rejected and the mother liquor from the last stage recovered as a product, whereby in a stage of said process ice crystals are introduced, said ice crystals having a larger medium size than the crystals in said stage formed without said introduction of said ice crystals.

Abstract: Process for separating the ice crystals contained in a slurry of an aqueous solution and ice crystals from the aqueous solution and washing the ice crystals with an aqueous wash liquid, whereby a packed bed of ice crystals is created which is subjected to a continuous translatory movement, while a washfront is being created within the packed bed of ice crystals between the aqueous solution and the aqueous wash liquid, the aqueous solution and the aqueous wash liquid adjacent to the washfront being substantially stagnant, a stable washfront being created lying in a plane perpendicular to the translatory movement of the packed bed of ice crystals.

Abstract: The treatment of dilute solutions and freeze concentrations thereof by means of steam jet refrigeration pre-cooling of a feed solution sprayed into an absorber-freezer means in which heat is absorbed from the jet refrigeration and from which ice slurry is charged into a melter-worker means discharging product melt and concentrated by-product, and super-cooled by vapor compression refrigeration wherein the refrigerant is simultaneously condensed and chilled by the steam jet refrigeration for pre-cooling the feed solution, steam power therefor being supplied by the Peltier effect in a diffusion still separating water and concentrated refrigerant.

Abstract: A system and method for concentrating aqueous beverages such as fruit juices, beer, wine, vinegar, tea, coffee, and the like in which a slurry of feed liquid and seed crystals is formed in a scraped surface heat exchanger of a first stage and supplied to a recrystallizer where larger crystals grow, the liquid in the recrystallizer being withdrawn with part recirculated to the heat exchanger of a succeeding stage. The slurry of larger crystals in the recrystallizer of the first stage is also withdrawn and the crystals separated in a wash column. The larger crystals grown in the second stage recrystallizer are supplied to the recrystallizer of the first stage where the seed crystals melt and reform on the larger crystals and the larger crystals from the third stage are similarly supplied to the recrystallizer of the second stage.

Abstract: A freeze concentration apparatus comprising a cold concentrator tank; a conduit to deliver an aqueous liquid mixture feed stream to the cold concentrator tank; a conduit to feed the liquid mixture from the cold concentrator tank to a freeze exchanger for indirect cooling by heat exchange to a cold fluid to form ice crystals in the liquid mixture; a conduit to feed the liquid mixture containing ice crystals from the freeze exchanger to the cold concentrator tank; a conduit to withdraw liquid mixture from the cold concentrator tank concentrated by the freezing of water therefrom; a conduit to withdraw an ice slurry from the cold concentrator tank and deliver it to an ice slurry washer; a spray system to wash the ice slurry in the washer with water a washer to collect washed ice and an aqueous mixture; a conduit to remove the aqueous mixture from the washer; and an unloader to remove the washed ice from the washer.

Abstract: An apparatus and process for purifying and separating a crystalline compound from its impurities in a slurry containing same, said process comprising introducing said slurry under pressure into a cylindrical pressurized filter-washer having a substantially constant inside diameter which is substantially free of protrusions, said filter-washer having a filter means with a screen contiguous with an internal surface of the cylinder, said screen having a smooth surface sufficient to provide minimum friction so as to allow a moving bed of crystals to move past it and withdraw a filtrate without blinding, filtering the crystals, withdrawing the filtrate, and moving the crystal bed past the filter screen, applying a controlled restraining force on the crystal bed so as to prevent relaxation and channeling and over-compacting of said bed by means of a compression and harvest means substantially contiguous with said inside diameter and located between said filter means and an exit means, said compression and harvest m

Abstract: Excessive energy consumption of a combination of multi-fractionations and multi-distillations of concentrating aqueous acetic acid product of liquid phase oxidations, especially oxidation of liquid n-butane with oxygen gas while the butane is dissolved in liquid acetic acid containing a catalyst system comprising Co-Br or Co-Mn-Br, is avoided and an otherwise hard to remove bromo-ketone is readily removed by a combination of sequential steps of decompressing the oxidation reaction mixture to remove unreacted butane as well as gaseous products, heat treating the decompressed liquid at a temperature of from 150.degree. C. up to 200.degree. C. for from 15 up to 150 minutes, subjecting the heat treated liquid to fractionation while recycling to the rectification zone thereof an aqueous portion of low boiling impurities as a means for concentrating the acetic acid and thereafter further concentrating the acetic acid produced by continuous fractional crystallization.

Abstract: Method and apparatus for continuously freezing and melting a fluid mixture, for use in separating a fluid mixture into dilute and concentrated components which have been made separble due to the freezing. A turbine is used to produce mechanical energy to drive a refrigeration compressor, while exhaust heat from the turbine is used for secondary cooling. Heat from a refrigeration condenser is used to melt the liquid frozen by a refrigerant evaporator. The evaporator and condenser may comprise a plurality of plates or may comprise a bubbler for bubbling refrigerant directly into contact with the fluid mixture.

Abstract: A process and apparatus are described for separating crystallizable mater from a liquid multi-component system involving a series of cycles wherein (a) the liquid is confined in a space having a large heat exchange surface; (b) heat is withdrawn from said surface to crystallize at least part of said material; (c) the crystallizable material is removed; (d) the crystallized material so removed is sub-divided; and (e) the resulting product is treated to separate the crystallized material from the rest of the multi-component system.

Abstract: Orange or other fruit juice is concentrated by forming ice therein and separating the ice from the juice in a draining column followed by centrifugation.

Abstract: A process is disclosed for recovering fresh water from brine which includes introducing brine, which has been inoculated with a predetermined number of ice nuclei and is at about its freezing temperature, into an elongated crystal growth zone which is supplied with refrigerant along the brine flow path at a graduated rate such that more refrigerant is supplied toward the outlet of the crystal growth zone than near the inlet. Ice crystals are separated from the resulting brine-ice slurry, and the ice crystals are washed with fresh water before being melted to recover fresh water.

Abstract: A process and system for separating a preferentially crystallizable component A from a feed, wherein a series of zones are used between which mother liquor can flow without passage of crystallized material. Liquid feed is introduced to a zone other than the end zone from which effluent rich in component A is withdrawn. During one stage gradating crystallization temperature pattern is established throughout the series ranging from relatively low to relatively high, causing component A to crystallize in each zone; and mother liquor is caused to flow toward the low temperature end, while a portion of previously withdrawn effluent rich in component A is returned to the higher temperature end and effluent lean in component A is removed from the lower temperature end.

Abstract: The invention is directed to an apparatus and method of purifying contaminated water by means of a two-step freeze crystallization process. The method and apparatus overcomes the serious problem caused by the freezing of water on the screen of the wash column. The solution comprises means and method of reducing the temperature difference between the concentrate and the wash water in the wash column.

Abstract: Pulping liquor borne solids are concentrated within an aqueous solution by a successive plurality of freezing steps wherein a discrete quantity of the solution is crystallized in each step by freezing. The water crystals from each freezing step are subsequently separated from the remaining liquid solution by screening and applying axial pressure to the crystalline mass. Greater efficiencies may be obtained in some cases by mixing or reslurrying a pressed, crystalline mass and pressing a second time. Another auxiliary separation step comprises a quiescent thaw of the crystalline mass from the first two press steps to permit additional dissolved solids to be drained away from the purified water ice.

Abstract: A single or multi-step fractional crystallization process and apparatus for separating fluid material having two or more components, the material flowing down a cooled wall surface and a component crystallizing thereon. Each step comprises a single crystallization and all steps of a complete cycle are conducted within a single crystallizer.