Liquid Refrigerant Converted To Vapor Phase During Cooling Patents (Class 62/534)
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Patent number: 11828509Abstract: A dynamic refrigeration system may include an ultrasonic transducer attached to a refrigerant flow sight glass, an expansion valve, and an evaporator coil in a refrigerant line. The ultrasonic transducer may be placed in a refrigerant flow of the refrigerant line before or after the expansion valve and before the evaporator coil, wherein sound waves of the ultrasonic transducer may break up large globules of refrigerant molecules into smaller globules of refrigerant molecules, thereby increasing total surface area of the refrigerant molecules to increase heat transfer capacity and total system efficiency. The system may provide 3-5 percent higher efficiency overall due to the presence of the ultrasonic transducer in the refrigerant line before or after the expansion valve.Type: GrantFiled: March 8, 2022Date of Patent: November 28, 2023Assignee: Joshua R&D Technologies, LLCInventor: David Pickett
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Patent number: 11242433Abstract: A solid-liquid separation device includes a kettle body, a piston, a stirrer, a separation plate having filtration pores, and a filtration mesh. The kettle body is hollow along an axial direction to form a chamber body. The separation plate is fitly installed in the chamber body, and divides the chamber body into a washing chamber and a draining chamber. The piston and the stirrer are fitly disposed in the washing chamber. The filtration mesh is attached on a side of the separation plate to cover the filtration pores. The kettle body is further provided with a feed inlet, a water inlet, a material outlet, and a liquid outlet. The feed inlet and material outlet are communicated with the washing chamber, and the water inlet and the liquid outlet are communicated with the draining chamber. The method includes the following steps: feeding, solid-liquid separation, washing, and material discharge.Type: GrantFiled: November 21, 2018Date of Patent: February 8, 2022Assignee: GUANGZHOU INSTITUTE OF ENERGY CONVERSION, ACADEMY OF SCIENCESInventors: Wen Wang, Xinshu Zhuang, Xuesong Tan, Qiong Wang, Qiang Yu, Wei Qi, Zhongming Wang
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Patent number: 8669860Abstract: A monitoring system and method for monitoring electrical, mechanical, and telecommunications equipment including air conditioning components of a facility is provided. The monitoring system can include door sensors, pressure sensors, and power phase loss monitors, which can be centrally connected to a transmitter for communication over a network for notifying client devices and activating alarms. The alarms can be provided when voltage drops, pressure drops, or a door has been opened.Type: GrantFiled: May 17, 2012Date of Patent: March 11, 2014Inventor: Ronnie Dean Tinsley, II
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Patent number: 7900473Abstract: The present invention provides a method for adiabatic cooling type crystallization of organic compound and an apparatus therefore, by which running cost and facility cost can be reduced. The method comprises carrying out adiabatic cooling and evaporation operation of a coolant in a crystallizer 20 for a mixture solution of a target organic compound containing the coolant; taking out crystal slurry produced by the operation from the crystallizer 20; pressurizing evaporated vapor to a pressure higher than the operation pressure in the crystallizer 20 by a compressor 30, introducing the vapor to an absorption condenser 10; cooling for condensation the mixture solution of organic compound and the evaporated vapor that has been pressurized while allowing them to contact each other in the absorption condenser 10; and introducing this absorption condensate to the crystallizer 20.Type: GrantFiled: March 7, 2006Date of Patent: March 8, 2011Assignee: Tsukishima Kikai Co., Ltd.Inventors: Keizo Takegami, Junji Wakayama, Kiwamu Ishii
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Publication number: 20100192625Abstract: The present invention provides a method for adiabatic cooling type crystallization of organic compound and an apparatus therefore, by which running cost and facility cost can be reduced. The method comprises carrying out adiabatic cooling and evaporation operation of a coolant in a crystallizer 20 for a mixture solution of a target organic compound containing the coolant; taking out crystal slurry produced by the operation from the crystallizer 20; pressurizing evaporated vapor to a pressure higher than the operation pressure in the crystallizer 20 by a compressor 30, introducing the vapor to an absorption condenser 10; cooling for condensation the mixture solution of organic compound and the evaporated vapor that has been pressurized while allowing them to contact each other in the absorption condenser 10; and introducing this absorption condensate to the crystallizer 20.Type: ApplicationFiled: March 7, 2006Publication date: August 5, 2010Inventors: Keizo Takegami, Junji Wakayama, Kiwamu Ishii
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Patent number: 7485234Abstract: Desalination apparatus based on porous restraint panels fabricated from a number of different layers of metal, thermoplastic, or other substances are used as sophisticated heat exchangers to control the growth of gas hydrate. The gas hydrate is produced after infusion of liquid hydrate-forming material into water to be treated, which liquid hydrate-forming material can also be used to carry out all the refrigeration necessary to cool seawater to near the point of hydrate formation and to cool the porous restraint panels. Hydrate forms on and dissociates through the porous restraints. The composite restraint panels can also be used in gaseous atmospheres where, for instance, it is desired to remove dissolved water.Type: GrantFiled: April 13, 2007Date of Patent: February 3, 2009Assignee: Marine Desalination Systems, LLCInventor: Michael David Max
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Publication number: 20080190135Abstract: An LNG plant is configured to receive rich LNG and to produce LPG, lean LNG, and power using at least one fractionation column, wherein the fractionation portion of the plant can be optionally thermally coupled to a power cycle utilizing residual refrigeration from the processed lean LNG. Most preferably, a liquid portion of the rich LNG is pumped to pressure and heated, and the pressurized and superheated portion is expanded to produce electric energy before being fed into the column. The column overhead vapor is partially condensed, providing column reflux for high NGL recoveries, and the residual vapor is further condensed using refrigeration content of the rich LNG forming the lean LNG product, that is further pumped to pipeline pressure and subsequently vaporized using heated working fluid of the power cycle.Type: ApplicationFiled: August 30, 2005Publication date: August 14, 2008Applicant: FLUOR TECHNOLOGIES CORPORATIONInventor: John Mak
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Patent number: 7073349Abstract: A method and apparatus for producing particles, the apparatus includes a solution source that supplies a solution, and a fluid source that supplies a fluid. The solution includes a solvent and a solute. A mixer receives the solution and the fluid from the sources, and mixes the solution and the fluid together to form a mixture. The mixture is supplied from the mixer to an expansion assembly at first pressure. The expansion assembly sprays and expands the mixture substantially simultaneously to form frozen droplets, and preferably to form a low-density powder of frozen droplets. A freeze-dry apparatus sublimes the solvent from the particles. A high mass-transfer rate and a uniform open-structure of the powder bed enhances the freeze-drying process. Solid particles having a controlled size distribution are obtained. The particles preferably have a hollow or porous morphology suitable for differing drug delivery applications to include aerosol formulations.Type: GrantFiled: March 11, 2005Date of Patent: July 11, 2006Assignee: Ferro Pfanstiehl Laboratories, Inc.Inventors: Boris Y. Shekunov, Pratibhash Chattopadhyay, Jeffrey S. Seitzinger
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Patent number: 6415628Abstract: A method and apparatus for providing direct contact refrigeration to a heat source wherein refrigeration is generated using a recirculating defined multicomponent refrigerant fluid, and transferred to a direct contact refrigerant fluid which directly contacts the heat source.Type: GrantFiled: July 25, 2001Date of Patent: July 9, 2002Assignee: Praxair Technology, Inc.Inventors: M. Mushtaq Ahmed, Theodore Fringelin Fisher
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Patent number: 5598712Abstract: A latent heat accumulation system having a transfer mechanism comprises a production tank in which water is put in direct contact with an antifreezing liquid which does not combine with the water, has a specific gravity greater than that of the water and is cooled to a preset temperature level, thus producing ice particles, a recovery section, formed at a lower part of the production tank, for recovering the antifreezing liquid descending within the production tank, an upward pipe, connected to the production tank, for guiding upward a two-phase stream of the water and ice particles within the production tank, a transfer pipe, connected to the upward pipe, for transferring the two-phase stream to a specified place, a reservoir tank for storing the two-phase stream transferred via the transfer pipe, a water circulation system for draining the water from the reservoir tank and introducing the drained water into the production tank, and an antifreezing fluid circulation system for cooling the antifreezing fluidType: GrantFiled: August 15, 1995Date of Patent: February 4, 1997Assignee: Kabushiki Kaisha ToshibaInventors: Yutaka Watanabe, Takayuki Hachimonji, Katsuya Yamashita, Sanae Sekita, Tsuyoshi Noma
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Patent number: 5566552Abstract: A Vapor Pressure Enhancement Direct Water Chiller, designated as a VPE chiller, a Vapor Pressure Enhancement Direct Water Heater, designated as a VPE heater, and a dual purpose integrated Vapor Pressure Enhancement Direct Water Chiller/Heater, designated as a VPE chiller/heater are introduced. A VPE-chiller comprises multiple pressure processing zones and is based on absorption vapor pressure enhancement operation. It comprises multitude of processing zones, Z-1, Z-2, . . . , Z-N that are operated under pressure P.sub.1, P.sub.2, . . . , P.sub.N. Each pressure zone (Z-n) contains a water evaporation zone (Z-En), a vapor pressure enhancement zone (Z-VPEn) and a second vapor condensing zone (Z-Xn). There are a set of rotating discs to provide water evaporation surfaces in the evaporation zone; there are flat heat conductive tubes for forming falling films of absorbing solution and falling films of water in the vapor pressure enhancement zone; there are condenser tubes in the condensation zone.Type: GrantFiled: July 17, 1995Date of Patent: October 22, 1996Inventor: Chen-Yen Cheng
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Patent number: 5564289Abstract: A cooling tank 1 for cooling water 2b by bringing water 2b in direct contact with hardly-water-soluble refrigerant 2c having a larger specific gravity than that of water, which tank 1 has an inside space 3 above water surface in the tank 1 and the pressure P.sub.t of the space 3 is kept below the saturation pressure P.sub.0 of the refrigerant 2c at water freezing point (P.sub.t .ltoreq.P.sub.0). The tank 1 also has a refrigerant extraction hole 6a for extracting gas-phase refrigerant 2c, an outlet 14a for drawing cooled water 2b, and an upward passage 30 for refrigerant extending from the bottom of the tank 1 to the water surface therein, which passage 30 guides ascension of that refrigerant 2c which settles at the tank bottom toward the space 3 above the water surface.Type: GrantFiled: March 21, 1995Date of Patent: October 15, 1996Assignee: Kajima CorporationInventor: Toshiyuki Hino
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Patent number: 5481882Abstract: A latent heat accumulation system uses latent heat for air-conditioning. The latent heat accumulation system includes a tank, supplying section, injecting section, drawing section and collecting section. The tank has a liquid storing section for storing Fluorinate (trade name) in the lower portion thereof, storing water which is cooled by ice via a boundary surface with Fluorinate in the middle portion thereof and storing the ice together with the water in the upper portion thereof. The supplying section supplies the water into the liquid storing section. The injecting section injects Fluorinate cooled to a preset temperature into the water stored in the liquid storing section. The drawing section draws out the water which is stored in the liquid storing section and cooled by the ice to the exterior of the tank as an air-conditioning heat accumulation medium. The collecting section collects a mixed fluid of the water and Fluorinate from the lower portion of the liquid storing section.Type: GrantFiled: April 5, 1995Date of Patent: January 9, 1996Assignee: Kabushiki Kaisha ToshibaInventors: Yutaka Watanabe, Takayuki Hachimonji, Katsuya Yamashita, Sanae Sekita, Tsuyoshi Noma
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Patent number: 5444986Abstract: An ice making refrigerant mainly consists of at least one compound selected from the group of normal perfluoropentane, cycloperfluoropentane, isoperfluoropentane, and fluorohydropentane. The refrigerant may also consists of pentane mixed with a sufficient amount of one or more of the above compounds for making the refrigerant substantially incombustible. The refrigerant is highly resistant to combustion and free from destroying the stratospheric ozone layer. Ice is produced by mixing the refrigerant in liquid phase with water at a pressure higher than the saturation pressure P.sub.0 of the refrigerant for 0.degree. C. and then ejecting the water-refrigerant mixture into a tank at a pressure below the above saturation pressure P.sub.0, so as to evaporate the refrigerant and let the water freeze by the latent heat of evaporation of the refrigerant.Type: GrantFiled: February 4, 1994Date of Patent: August 29, 1995Assignee: Kajima CorporationInventor: Toshiyuki Hino
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Patent number: 5409505Abstract: Adiabatic self-evaporation cooling of a refrigerant is performed in a crystallizer for a treated organic matter which contains the refrigerant and is fed into the crystallizer. Crystals produced by the adiabatic self-evaporation cooling are withdrawn from the crystallize. An evaporated vapor is introduced from the crystallizer into an absorber so as to be contacted with a concentrated solution transformed from a generator for condensation in the absorber. A condensate is introduced from the absorber into the generator, the refrigerant is evaporated in the generator, an evaporated vapor is introduced from the generator to the condenser, the evaporated vapor is condensed in the condenser, a condensate is supplied from the condenser to the crystallizer and the concentrated solution is circulated between the absorber and the generator by returning the concentrated solution, in which the concentration of an absorbent is increased by the generator to the absorber.Type: GrantFiled: April 30, 1992Date of Patent: April 25, 1995Assignee: Tsukishima Kikai Co., Ltd.Inventors: Minoru Morita, Keizo Takegami
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Patent number: 5307640Abstract: This invention relates to an apparatus and process for producing frozen particles of a liquid product having a liquid product nozzle for introducing liquid product droplets to be frozen and a plurality of cryogenic nozzles for introducing a cryogenic liquid directed away from the liquid product droplets.Type: GrantFiled: January 25, 1993Date of Patent: May 3, 1994Assignee: E. I. Du Pont de Nemours and CompanyInventors: Abdel A. Fawzy, Alferd J. Forestell
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Patent number: 5218828Abstract: The method stores heat in ice by freezing water through its direct contact with a hardly-water-soluble refrigerant; i.e., water is mixed with the refrigerant at a high pressure to produce a liquid mixture while preventing evaporation of the refrigerant, and the liquid mixture is jetted from a nozzle into a space at a lower pressure, whereby the refrigerant evaporates at the lower pressure and the water in the liquid mixture is frozen into sherbet-like ice and dispersed over a wider area than in the case of non-sherbert-like ice. A device based on the method uses a heat-insulating water tank whose top space above water level therein is kept at a pressure P2 lower than saturation pressure P0 (P2<P0) of the refrigerant for water freezing point 0.degree. C. A mixer mixes the refrigerant of liquid phase and water at a pressure P1 which is higher than the saturation pressure P0 of the refrigerant for water freezing point 0.degree. C.Type: GrantFiled: October 23, 1992Date of Patent: June 15, 1993Assignee: Kajima CorporationInventor: Toshiyuki Hino
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Patent number: 4952750Abstract: This process is an improvement of a process described in German Open Patent Application No. 3703646 for obtaining a p-xylene product with a purity of at least 99.5%. The inert fluid used as a cold carrier is mixed with a crude product starting material, which has a high p-xylene content, in a mixing vessel under rotation to form a resultant mixture. Subsequently the resultant mixture is concentrated to a crystal content of from 30% to 70% and after that the p-xylene crystals are separated in a separator. The purity of the product p-xylene can be increased by heating these crystals in the separator.Type: GrantFiled: April 14, 1989Date of Patent: August 28, 1990Assignee: Krupp Koppers GmbHInventor: Guenter Puppel
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Patent number: 4952224Abstract: A method and apparatus for converting liquid fats into solid particles for blending with dry feed ingredients comprises spraying atomized liquid fat into the upper portion of the mixing chamber while directing a plurality of fine jets of liquid nitrogen against the liquid fat spray so as to produce solid fat particles which fall into the dry ingredients at the bottom of the mixing chamber. A homogeneous mix free of fat lumps is thereby readily obtained, even at the higher percentages of fat required for some animal feed.Type: GrantFiled: April 17, 1989Date of Patent: August 28, 1990Assignee: Canadian Oxygen LimitedInventor: Louis Lilakos
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Patent number: 4864831Abstract: An ice storage refrigerating apparatus of direct contact type comprises a closed crystallizer tank containing water therein and a refrigerant circulating system. A refrigerant consisting essentially of a hydrocarbon having four carbon atoms and/or a hydrocarbon having five carbon atoms is brought into direct contact with the water contained in the crystallizer tank to form ice in sherbet form which is used for heat exchange to provide chilled water used for air conditioning.Type: GrantFiled: July 11, 1988Date of Patent: September 12, 1989Assignee: Kajima CorporationInventor: Toshiyuki Hino
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Patent number: 4840652Abstract: A method and apparatus for generating, by siphon effect, in a housing containing a cold-accumulating and freezable liquid, a current of liquid in a closed hydraulic circuit, the current of liquid comprising at least one ascending current which is located over means for injecting a refrigerating fluid and which contains bubbles of atomized refrigerating fluid, and at least one descending current free of refrigerating fluid in the gaseous phase.Type: GrantFiled: September 17, 1987Date of Patent: June 20, 1989Assignee: Coldeco S.A.Inventors: Laszlo Simon, Jean Pfau
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Patent number: 4838039Abstract: A direct contact evaporator-freezer comprising a body defining a chamber having an upper vapor discharge opening and a lower aqueous slurry discharge opening; a conduit to supply an aqueous liquid to the chamber at a rate which produces a pool of liquid in the chamber while aqueous slurry is discharged therefrom; and a nozzle to spray a liquid refrigerant in the form of small high velocity droplets into the aqueous liquid in the chamber.Type: GrantFiled: April 21, 1988Date of Patent: June 13, 1989Assignee: CBI Research CorporationInventor: Bryan D. Knodel
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Patent number: 4596120Abstract: A method comprising feeding a liquefied refrigerant gas into direct contact with aqueous liquid in an enclosed vessel to chill or cool the liquid and/or produce ice crystals and vaporize the refrigerant by heat exchange with the aqueous liquid; feeding a mixture of cold aqueous liquid and/or ice and refrigerant from the vessel to an enclosed storage tank to provide cold aqueous liquid and/or ice therein; removing refrigerant vapor from the storage tank; converting the refrigerant vapor to liquid refrigerant in a refrigeration cycle and feeding the liquid refrigerant back to the enclosed vessel; and withdrawing aqueous liquid from the storage tank and feeding it to the enclosed vessel; with all said refrigerant and aqueous liquid streams and volumes being in a single closed system such that refrigerant and aqueous liquid are not lost except by inadvertent leaks and consumption of such materials is avoided because they are not withdrawn from the system.Type: GrantFiled: November 30, 1984Date of Patent: June 24, 1986Assignee: Chicago Bridge & Iron CompanyInventors: Bryan D. Knodel, John S. Ludwigsen, Jill L. Ludwigsen, Terry A. Gallagher
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Patent number: 4452621Abstract: A crystallization process is improved by employing direct contact cooling whereby a volatile liquid is vaporized to provide the cooling necessary to effect the crystallization. The effluent vapors of the volatile liquid may be liquified and recycled for reuse by manipulation of temperature and/or pressure. In one embodiment, durene is crystallized from a C.sub.10.sup.+ aromatics fraction using liquified n-butane as the coolant.Type: GrantFiled: September 27, 1982Date of Patent: June 5, 1984Assignee: Mobil Oil CorporationInventors: Patrick E. Fowles, Tsoung Y. Yan
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Patent number: 4319962Abstract: A continuous autorefrigerant solvent dewaxing process is disclosed wherein a waxy oil is prediluted with a non-autorefrigerative solvent, such as ketone, preferably a mixture of MEK/MIBK, and then passed, at a temperature above its cloud point, to the top of a chilling zone, which is an autorefrigerant chilling zone operating on a continuous basis, and comprises a vertical, multi-staged tower, operating at constant pressure. In this chilling zone, wax is precipitated from the oil to form a waxy slurry and the so-formed slurry is further chilled down to the wax filtration temperature by stage-wise contact with liquid auto-refrigerating preferably propylene, which is injected into a plurality of said stages and evaporated therein so as to cool the waxy slurry at an average rate of between about 0.1.degree. to 20.degree. F. per minute with an average temperature drop across each stage of between about 2.degree. and 20.degree. F.Type: GrantFiled: November 5, 1979Date of Patent: March 16, 1982Assignee: Exxon Research & Engineering Co.Inventor: Douglas R. Ryan
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Patent number: 4291549Abstract: A hollow, rotating drum is horizontally supported in a vessel or crystallizer containing a brine such as sea water and has a plurality of nozzles projecting radially outwardly therefrom and having orifices having a smaller diameter than the nozzles. A liquified refrigerant is introduced through a conduit and a hollow shaft into the drum and is discharged as droplets into the brine while the drum is being rotated at high speeds in the brine. Upon getting into the brine, the refrigerant is vaporized and takes away heat of the brine, which is then refrigerated to form small crystals of ice.Type: GrantFiled: December 19, 1979Date of Patent: September 29, 1981Assignee: Ube Industries, Ltd.Inventors: Kensuke Fujimura, Naomichi Yamamoto, Masahiro Ogawa, Nobuyoshi Tanigawa
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Patent number: 4207351Abstract: A process for removing water from an aqueous solution. A hydrate forming fluid is contacted with an aqueous solution at a temperature below the maximum temperature at which said hydrate forming fluid forms a solid hydrate in the presence of said solution and at a temperature at which there is precipitation of solid solute and/or of the concentrated solution remaining after hydrate formation so as to form a magma comprising solid hydrate, any unreacted hydrate forming fluid and any unreacted aqueous solution. The hydrate forming fluid and at least part of the water constituent of the solid hydrate are separated from the solute by fractional sublimation, evaporating and/or elution to produce a substantially hydrate forming fluid-free product comprising said solute and any remaining water.Type: GrantFiled: June 2, 1977Date of Patent: June 10, 1980Assignee: British VinegarsInventor: Thomas M. C. Davies
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Patent number: 4177653Abstract: A method for separating collidal zeolite crystals from aqueous mother liquor solutions with conventional filtration apparatus by initially freezing the dispersion to a slush and conducting the filtration operation as the slush melts.Type: GrantFiled: October 20, 1978Date of Patent: December 11, 1979Assignee: Chevron Research CompanyInventor: Donald A. Hickson
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Patent number: 4129583Abstract: In a continuous process for separating crystallizable organic components from mixtures thereof in solution, a feedstock of such components is mixed with at least one solvent therefor and the resulting feedstock mixture is continuously fed into a vessel in which a baffle defines a partially confined first zone and a partially confined second zone communicating with the first zone. At least one low-boiling point high-vapor pressure refrigerant is injected into the feedstock mixture in the first zone and evaporates and adiabatically expands therein to effect rapid cooling of the mixture to a selected low temperature and thereby form a slurry of microcrystals of components which are crystallizable down to the selected temperature.Type: GrantFiled: January 24, 1978Date of Patent: December 12, 1978Inventor: Klaus Zondek
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Patent number: 4116652Abstract: The invention is directed to freeze concentration of liquid mixtures including solutions by the direct contacting in at least two stages, of the mixture with a miscible refrigerant. After the contacting of the refrigerant with the liquid mixture, there is provided a first stage crop of substantially pure crystals of a mixture component which is separated from the mother liquor. The mother liquor is then further cooled and crystallized in further stages. Any crystals from said further stages are returned to the first or preceeding stage. This concentrates the second stage and further stage mother liquors.This process is applicable to the freeze concentration of juices, coffee or tea extracts and beers. It also may be utilized for the purification of brackish water. The purity of the first stage crystals is assured by controlled crystal growth. The successive stages provide for a complete concentration of the residual matter in the mother liquor.Type: GrantFiled: May 17, 1976Date of Patent: September 26, 1978Inventor: Klaus Zondek
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Patent number: 4046534Abstract: 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.Type: GrantFiled: April 26, 1973Date of Patent: September 6, 1977Inventor: James B. Maguire, Sr.
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Patent number: 3997331Abstract: A process and apparatus for producing certain metal salts in very fine particulate form. The process comprises cooling a solution of metal salt until the solution freezes and thereafter evaporating the solvent under very low pressure. The process is particularly applicable to salts of tungsten and nickel from which sub-micron particles of tungsten and nickel can be produced.Type: GrantFiled: August 13, 1973Date of Patent: December 14, 1976Assignee: Crysus (Lancashire) LimitedInventor: Denis Tither
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Patent number: 3992900Abstract: 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.Type: GrantFiled: December 27, 1974Date of Patent: November 23, 1976Assignee: Avco CorporationInventor: Robert J. Campbell