Abstract: The invention is method and apparatus for removing dissolved solids from water by creating a condition of super-saturation of the solids material within a confined water circuit, propagating the formation of solids by a process of crystal nucleation and crystal growth and separating the crystallized solids. The invention also involves the apparatus for carrying out the process including a continuous process circuit for circulating a super-saturated liquor, which circuit comprises a source of heat energy for propelling the process and a cooling tower to provide evaporation and super-saturation, and further including a separator to remove crystallized solids from the liquor.

Abstract: Apparatus for forming a vortex includes inner and outer wall structures. The inner wall has a downward flow passageway therewithin. A plurality of vanes are provided between the wall structures to induce a vortex to form from an upward flow of liquor through the annular passageway between the walls. The wall structures form a settling trough into which solid materials may settle and accumulate.

Abstract: An immersion evaporator is disclosed having, connected to its evaporation vessel, a pipe for feeding a solution to be concentrated by evaporation into the evaporation vessel, a riser pipe for withdrawing the concentrated solution and any crystals from the evaporation vessel, a pipe for withdrawing flue gases and vapors from the evaporation vessel, and an immersion pipe extending vertically inside the evaporation vessel, the upper end of the immersion pipe being connected, by means of an angle joint piece to the outlet of the combustion chamber, there being at the opposite end of the combustion chamber, a burner for liquid or gaseous fuel, the burner having a cylindrical combustion gas turbulence chamber for an oxygen-bearing combustion gas, at one end of which there is a substantially tangential combustion gas inlet conduit and a fuel dispersion pipe extending coaxially into the turbulence chamber, the opposite end of the turbulence chamber being convergent.

Abstract: Disclosed is an improved method of producing potassium chloride by concentrating a brine thereof with respect to potassium chloride by multiple stage evaporation conducted at progressively higher temperatures, thereby precipitating other salts and thereafter cooling the brine in multiple stage crystallizers operated at progressively lower temperatures, thereby precipitating potassium chloride crystals. The improvement comprises cooling the brine in hotter crystallizer utilizing streams to or between cooler evaporators whereby in addition heat is provided to the evaporator stream.

Abstract: Apparatus is disclosed for treating pickling solutions used for pickling metal, such as iron, steel, special alloys, or the like. In a preferred embodiment, the apparatus includes an evaporator, a condensor, a crystallizer, a crystal-separating device, fittings and conduits for connection to the metal-treating plant, and a device for automatically controlling the evaporation rate in the evaporator. The evaporator includes a flow channel, vapor removal connection above the liquid level in the flow channel, an inlet and outlet for the solution being treated, and a plurality of electrodes for directly applying AC current to the solution. The electrodes are mounted spaced along the length of th flow channel and are completely covered by the solution so as to be out of contact with the vapor. The crystallizer comprises an upright cylindrical vessel having an inlet and an outlet, a driven shaft extending in the center line of the vessel, and is provided with radial ribs.

Abstract: A modular chlorine dioxide generating unit (10) is disclosed wherein recycled reaction mixture passes along a flow path (18) internally of the generator vessel (12) out of direct fluid flow communication with the reaction medium (13) from the lower end (16) of the vessel (12) to a discharge point in the vapor phase (15 ) above the liquid level (13) in the generator vessel (12).

Abstract: To remove salts from a solution containing the salts, hot air is injected downwards into the solution in a concentrator, and the solution is concentrated by direct contact with the hot air, thereby enhancing an evaporation efficiency in the concentrator and preventing scale deposition in the concentrator and piping system. The solution is forcedly cooled in a crystallizer by direct contact with cool air, thereby making crystals grow in the solution within a short time. The solution and air are circulated in a closed cycle, thereby preventing a secondary environmental pollution.

Abstract: Disclosed are after-treatment processes and apparatus for synthesis plants, particularly urea and ammonium nitrate plants, but applicable also to various other plants in which the synthesis reaction does not go to substantial completion. In such plants product is fed to an evaporator for concentration and then to a solidification stage. The vaporous overhead stream from the evaporator contains entrained synthesis product, one or more unreacted starting materials, and solvent (usually H.sub.2 O). It is condensed, and the condensate is brought into mass and heat exchange relationship with the vaporous overhead stream from the evaporator substantially without material transfer of solvent to the condensate stream. The condensate stream is thereby enriched in synthesis product, heat is added to it, and unreacted starting material is desorbed from it. The product-enriched condensate is delivered to the solidification stage for processing there.

Abstract: Disclosed is an improved method of concentrating an aqueous solution containing a first salt and a second salt, the solubility of the first salt increasing more with increasing temperature than the solubility of the second salt, by multiple effect evaporation, wherein the multiple effect evaporators are backward fed, wherein the first evaporator effect is the hottest, wherein second salt is precipitated during evaporation, wherein the concentrated mother liquor is forwarded to a zone operated at atmospheric pressure, and wherein mother liquor effluent from the zone operated at atmospheric pressure is forwarded to a zone wherein the first salt is recovered.

Abstract: Urea granules are prepared by spraying an aqueous urea solution having a urea concentration of 70-99.9% by weight on to fluidized urea nuclei in the form of droplets having a mean drop diameter of 20-120 .mu.m at a temperature at which the water is evaporated from the solution sprayed on to the nuclei and urea crystallizes on the nuclei to form granules having a desired size.

Abstract: Disclosed is an improved method of concentrating with respect to a first salt an aqueous solution containing the first salt and a second salt, the solubility of the first salt increasing more with increasing temperatures than the solubility of the second salt, by multiple stage evaporation at progressively higher temperatures and backward feed, wherein first salt and second salt is precipitated in an evaporator stage which communicates with an elutriation leg, wherein an aqueous slurry containing first salt and second salt is withdrawn from the elutriation leg and wherein the concentrated solution is forwarded to a step where the first salt is recovered. In the improved method, slurry withdrawn from the evaporator stages is leached with raw feed and/or mother liquor from this step in which the first salt is recovered to dissolve first salt from the slurry and return the dissolved first salt to the evaporator effect.

Abstract: A vacuum pan is controlled by directly monitoring the total solids concentration of a boiling solution. A preferred type of process relates the change in concentration of sugar in a massecuite to the growth rate and increase in the number of crystals, and uses this relationship to control the rate of growth of the crystals by setting temperature and pressure to correspond to the rate of crystal growth desired. Water is evaporated from the pan solution at reduced temperature and pressure. Massecuite is withdrawn from the pan, and split into two streams: (1) a first stream wherein the mother liquor is separated from the sugar crystals and analyzed to determine the total sucrose content of the stream, and (2) a second stream which is analyzed to determine the count and size of the crystals. The sum-total of the two streams is used to determine the total concentration of sugar. Readings taken over definite intervals determine the rate of growth of the crystals.

Abstract: A method for evaporating a liquor comprised of a solvent and solute in a multiple external heat exchanger type evaporator having a vapor body means with an inlet means and an outlet means comprising the steps:1. Passing the liquor out of the vapor body outlet means into a first heat exchanger means, having an inlet means and an outlet means;2. Passing the liquor from the outlet means of the first heat exchanger means to an inlet means of a second heat exchanger means, said second heat exchanger means also having an outlet means;3. Passing the liquor from the outlet means of the second heat exchanger means into the vapor body means;4. Heating the liquor at a temperature greater than its boiling point as it passes through the multiple heat exchanger means; and5. Vaporizing a portion of the solvent segment of the liquor in the vapor body after the liquor leaves the multiple heat exchanger means.

Abstract: This invention pertains to a low head semi-continuous vacuum pan system for crystallization of a substance from solution of the substance, including the crystallization of a sugar from a sugar solution, that includes a sequential array of individual vacuum pans, wherein each pan has an associated discharge volume and the array is formed by positioning each pan so that its discharge volume is greater than the discharge volume of the immediately preceding pan and wherein heat and top-up solution are supplied to each pan and periodically all the contents of each pan are transferred to an immediately following pan and wherein controls are used to insure that the transfer takes place when the volume of each pan's contents reaches its associated discharge volume and the controls preferably ensure that each pan is empty before it receives the contents of the immediately preceding pan. This invention also pertains to a method of crystallizing a substance from a solution of the substance.

Abstract: A processing housing containing a primary stage spray chamber, a filter stage and redryer chamber, a second stage drying chamber and a cooling stage chamber all in communication one with the other. The primary stage spray chamber has an outlet at the lower end thereof and at least one hot gas inlet port thereof in the upper portion thereof with a source of drying gas connected thereto. At least one spray nozzle extends into the spray chamber and a draft producing means is provided to force the drying gas from the gas source through the spray chamber and out through the outlet thereof. An endless connecting belt is supported for horizontal movement adjacent the outlet of the spray chamber, said belt traveling from the primary stage spray chamber through the filter stage redryer chamber, then through the second stage drying chamber and then through the cooling stage chamber.

Abstract: A method and apparatus for recovering flux salt and recycling or reusing the same in an aluminum refining method by introducing salt brine into a cylindrical evaporator with hot evaporator gas, rotating the evaporator to expose the brine to the hot gas and removing the slurry from the evaporator.

Abstract: Preheated saline water, typically sea or brackish water, is further heated by quanta of steam, passed to it at differential temperatures and pressures and condensed in the saline water. Scale compounds are precipitated and scale-forming bicarbonates decomposed, with the evolution of carbon dioxide, which is gathered and expelled by steam accessory to the quanta of steam. Post-thermal saline water, which is formed, is multistage flash vaporized while self-cooling. The flashed vapors are compressed to form said quanta of steam. After being further cooled while preheating saline water, post-thermal saline water is evaporated in a multistage vapor compression evaporator, producing brine at a high concentration factor. Relative to equilibrium in scale-compound precipitation between 302.degree. F and 347.degree. F, the recovery of fresh water is 70% to 80% for sea water, and 80% to 90% for brackish waters over a wide range of salinity.

Abstract: In a continuous sugar evaporator-crystallizer having a plurality of evaporating-crystallizing vessels as stages, each evaporating-crystallizing stages being communicated one to another in series and being provided with a means for feeding an aqueous sugar solution, a heating means and a means for withdrawing generated steam, by feeding an aqueous sugar solution to each evaporating-crystallizing stage, heating the aqueous sugar solution in each evaporating-crystallizing stage, thereby evaporating water off the aqueous sugar solution and crystallizing sugar crystals, and withdrawing the generated steam from each of the stages, while feeding seed sugar crystals to the first evaporating-crystallizing stage and withdrawing the resulting sugar crystal slurry from the last evaporating-crystallizing stage, sugar crystals of high quality is obtained in the slurry with an effective suppression of occurrence of conglomerated sugar grains by providing sugar crystal distances of 0.26 to 0.

Abstract: The invention is a method for removing dissolved solids from water by creating a condition of super-saturation of the solid material within a confined water circuit, propagating the formation of solids by a slurry process of evaporative crystallization which utilizes waste heat energy and separating the crystalized solids; the invention also involves the apparatus for carrying out the process which includes a continuous process circuit for circulating a super-saturated liquid and slurry, which circuit comprises a source of waste heat energy for propelling the process and cooling tower to provide evaporation, and further including a separator to remove crystallized solids from the slurry.

Abstract: A method and a device for obtaining sugar crystals from a sugar solution by concentrating the thick juice emanating from the multi-stage evaporator in a continuously operating pre-concentrator to a concentration at which seed granulate could be added to the boiling pan, by raising the pressure of the concentrated thick juice, by supplying the juice to a buffer vessel in which the juice is subjected to a higher pressure than the pressure at which it is concentrated, the temperature being maintained and the contents of the vessel being thoroughly stirred and by filling the boiling pan from the buffer vessel while simultaneously seed granulate is added.

Abstract: Sugar is continuously crystallized from a sugar bearing solution in a single stage vacuum pan by a method and apparatus comprising means for and the steps of continuously supplying a sugar bearing solution of a constant, desired purity to the vacuum pan by combining a relatively low purity sugar bearing solution flow stream with a relatively high purity sugar bearing solution flow stream while regulating the ratio of relatively low to relatively high purity sugar bearing solution in the combined flow stream, continuously supplying sugar seed crystals having a relatively uniform crystal size distribution to the vacuum pan, continuously boiling at least a portion of the sugar bearing solution and sugar seed crystals in the vaccum pan to form a boiling massecuite, and continuously removing at least a portion of the massecuite from the vacuum pan.

Abstract: An improved closed-loop process is described for treating waste water resulting from chemical extraction of uranium from ore. The water is evaporated to form a concentrated solution and is then subjected to crystallization of the least soluble salt component thereof via further evaporation, or cooling or simultaneous cooling and a partial vacuum. The crystallized component is then separated from the mother liquor, whereupon the latter is fed back after removal of residual uranium therefrom to the the extraction installation to replace the acids used therein. Additionally, the pure condensate produced during evaporation of the waste waters is employed as a replacement for the fresh water employed in processing of the ore.

Abstract: A crystallizable solute is crystallized from a solution containing the same by introducing a solution of said solute into a first stage evaporative-crystallization zone together with seed solute crystals. Within the first stage evaporative-crystallization zone the solution is concentrated to yield a saturated first stage concentrate containing crystals of said solute. The crystals of said solute are substantially larger than said seed crystals and are suspended in a solution more concentrated with respect to said solute than the solution supplied to said first evaporative-crystallization zone. A stream of said first concentrate is removed from said first evaporative-crystallization zone and transferred to a second evaporative-crystallization zone for further concentration or crystallization of solute and for the production of solute crystals of increased size.

Abstract: A method and apparatus for cooling aqueous alkali metal hydroxide liquors such as, for example, caustic soda liquors, involving the vacuum cooling of a body of such liquor in an evaporating chamber having a overhead vapor outlet which communicates with a direct-contact barometric condenser supplied with a stream of cooled alkali metal hydroxide liquor. The cooled alkali metal hydroxide liquor has a vapor pressure below the absolute pressure of water vapor evolved from the body of liquor in the evaporating chamber and condenses the water vapor upon contact therewith. A stream of cooled concentrated alkali metal hydroxide liquor withdrawn from the evaporating chamber is, in accordance with a preferred embodiment of the present invention, further cooled and solids contained therein, such as, for example, sodium chloride crystals, are then removed in a suitable liquid-solids separation device.

Abstract: Improvements in the concentration of solutions in processes involving heating the solution to be concentrated; Processes of solution concentrating where the solution to be concentrated is heated prior to concentration by either direct or indirect heat exchange, including particular concentrating processes where the heating means and media include: (1) high pressure steam; (2) low-pressure steam and (3) submerged combustion; Improved methods of vapor-liquid phase separation in solution concentrating processes with the vapor phase utilized as supplemental heating medium to the solution to be concentrated; Incorporation of a counterflow gas-liquid contact stage (cooling tower) as one phase in processes of concentrating heated solutions.

Abstract: Saline water, typically sea water or brackish water, after deaeration and deoxygenation is preheated, then further heated by steam condensing with the preheated saline water. By the further heating, bicarbonates are thermally decomposed, forming carbon dioxide, while scale compounds, comprising magnesium hydroxide, anhydrite and minor compounds containing silica, iron, alumina, phosphate, etc., are thermally precipitated. Some of the steam is uncondensed and issues from the further heated saline water with included, evolved carbon dioxide. It is condensed in preheating saline water; evolved carbon dioxide is separated from the condensate and recycled to the saline water to prevent alkaline scale in preheating, while condensate is combined with the further heated saline water, forming post-thermal saline water. This is flash vaporized while cooling and the steam is regenerated by compressing the flashed vapors.