19 results about "Vacuum sublimation" patented technology

A production process of electronic grade molybdenum dichloride dioxide comprises the following steps: S1, pretreatment: contacting molybdenum trioxide with a dilute acid solution at a low temperature for pickling to remove alkaline impurities and soluble metal impurities adsorbed on the surface, and drying for later use after washing; s2, wet synthesis: in an inert gas atmosphere, reacting the molybdenum trioxide subjected to acid pickling in the step S1 with concentrated hydrochloric acid of which the mass is 4-5 times of that of the molybdenum trioxide at 80-100 DEG C, and after the reaction is finished, evaporating and concentrating in a high-temperature chlorine atmosphere to generate a crude product of dichloromolybdenum dioxide; s3, primary sublimation purification; s4, complexing and decomplexing purification; and S5, secondary sublimation purification: using a quartz sublimation tower to carry out vacuum sublimation on the secondary decomplexed molybdenum dichloride obtained in the step S34, and collecting sublimation condensate to obtain the electronic grade molybdenum dichloride. The final product purity of the production process is greater than or equal to 6N, and the process can be used for large-scale production.

The invention provides a purification method of a naphthalimide high-purity electronic-grade photoacid generator. The method solves the problem that photo-acid cannot be purified by traditional recrystallization or directly through ion exchange columns and other methods. The method comprises the following steps: firstly synthesizing and preparing 1, 3-diketone-2-hydroxy-6-(1-hexyne) benzisoquinoline, then reacting with triethylamine and trifluoromethylsulfonyl chloride to generate a crude product 1, 3-diketone-2-(1, 1, 1-trifluoromethyl) methanesulfonic ester-6-(1-hexyne) benzisoquinoline, removing impurities from normal hexane to obtain a pure product, sublimating the material into a gas phase by using a quartz vacuum sublimation instrument, and purifying to obtain the 1, 3-diketone-2-(1, 1, 1-trifluoromethyl) methanesulfonic ester-6-(1-hexyne) benzisoquinoline. And then passing through Pure MTS9500 amino phosphonic acid type chelating resin, and finally cooling in a quartz tube to obtain the high-purity electronic-grade photoacid generator. According to the invention, the stability is high, the metal ion content is low, the purification process is convenient to process, the product is used as a photoresist-level core main material, the product is widely applied in the fields of semiconductor photoresist, other imaging systems, photocureable coatings and the like, the market scale is continuously expanded, and the product is an indispensable key material in semiconductor manufacturing and other related fields.

The invention discloses a radio frequency freeze dryer applied to edible mushroom biscuit making and a freeze-drying method, and relates to the technical field of freeze-drying, the radio frequency freeze dryer comprises an integrated radio frequency source, a first radio frequency polar plate, a second radio frequency polar plate, a vacuum material cavity, a vacuumizing device, a cooling device and a material tray, the first radio frequency polar plate is connected with the integrated radio frequency source, and the second radio frequency polar plate is connected with the second radio frequency polar plate; the second radio frequency polar plate is grounded, the first radio frequency polar plate and the second radio frequency polar plate are arranged in the vacuum material cavity at intervals, the vacuumizing device and the cooling device are both connected with the vacuum material cavity, and the material disc is arranged between the first radio frequency polar plate and the second radio frequency polar plate; the materials are freeze-dried in the two stages of vacuum sublimation drying and desorption drying through radio frequency, heating is conducted from the interior of the materials in the freeze-drying process, the heating efficiency can be improved, energy consumption can be reduced, the radio frequency has the advantage of being high in penetrability, processing of the materials in the multi-layer stacked material disc can be achieved, and the processing efficiency of the materials in the multi-layer stacked material disc is improved. And the production efficiency can be improved.

This invention discloses a method for preparing tin dioxide powder by freeze-drying to inhibit tin hydroxide agglomeration. The method involves adding a tin source solution (36-54 g / L) and a precipitant solution (5-30 g / L) at a mass ratio of 1:0.1-0.25 under constant temperature and magnetic stirring. The precipitant solution is then added dropwise to the tin source solution, reacting to form tin hydroxide colloid. After static aging, the colloid undergoes rapid cryogenic freezing to instantly freeze it into an ice state. The ice-state colloid is then subjected to low-temperature vacuum sublimation drying to obtain loose tin hydroxide dry powder. The dry powder is then calcined to obtain tin dioxide powder. This invention fundamentally eliminates the agglomeration of tin dioxide powder, resulting in tin hydroxide dry powder with an agglomeration rate of less than 10% and a purity of over 99.9%, providing a high-quality precursor for high-performance electronic-grade tin dioxide.

The application discloses a carbon nanotube dispersion system, a high-cleanliness carbon nanotube oriented array and a preparation method. The preparation method of the high-cleanliness carbon nanotube oriented array comprises the following steps: uniformly mixing carbon nanotubes, an organic solvent and nitrogen-doped or non-nitrogen-doped pentacene system molecules to form a carbon nanotube dispersion system; immersing a substrate into the carbon nanotube dispersion system in a light-proof environment to prepare a carbon nanotube oriented array; and finally irradiating the carbon nanotube oriented array with ultraviolet rays, and then performing solution immersion and vacuum sublimation to obtain the high-cleanliness carbon nanotube oriented array. The carbon nanotube dispersion system provided by the application uses nitrogen-doped or non-nitrogen-doped pentacene system molecules as a dispersant, and the dispersant can be decomposed by ultraviolet irradiation, so that the dispersant will not be finally left on the surface of the carbon nanotubes, and the high-cleanliness carbon nanotube oriented array can be prepared.

The invention relates to the field of numerical simulation, in particular to a two-dimensional water vapor diffusion numerical simulation method for vacuum sublimation, rehydration and thawing, which comprises a vacuum box area, a water vapor generation area, a water vapor conveying area, a frozen product area and a flow velocity measuring point. Numerical simulation of a vapor diffusion process in a rehydration stage of vacuum sublimation, rehydration and thawing is performed through Workbench software, so that vapor diffusion conditions under different working conditions are determined, and performance quality analysis can be performed on the vapor diffusion conditions. According to the invention, a new thought is provided for reducing the cost of data acquisition in the water vapor diffusion process and optimizing vacuum sublimation, rehydration and unfreezing.

The invention relates to the field of thawing, in particular to a food thawing system special for vacuum sublimation rehydration thawing. Comprising a vacuum unfreezing box shell, a vacuum unfreezing box door, a rotating shaft, a sealing strip, a drying filter, a roots pump, a rotary vane pump, a vacuum exhaust pipe section, a liquid viewing mirror, an oil filling position, an oil discharging position, a heating plate, a heat insulation plate, a storage net, a supporting stand column, a supporting buckle, a four-claw hanging bracket and the like. According to the system, the vacuum thawing box is connected with the vacuum system, the heating plate system and the rehydration system, so that a vacuum sublimation stage and a rehydration heating stage in vacuum sublimation rehydration thawing can be realized, and frozen products can be efficiently thawed; and the system is provided with a part for adjusting the position of the heating plate, so that the system is suitable for a plurality of rehydration ports and the like in different unfreezing scenes, working condition parameters can be conveniently adjusted, and the vacuum sublimation rehydration unfreezing effect is further improved. Through the design of the invention, a new thought is provided for optimization of a food thawing process.

The application discloses a kind of electrochemical oxidation-membrane separation coupling green preparation furfuryl acid method.The method uses industrial grade furfural as raw material, selects transition metal composite electrode as anode, multiple electrode as cathode, and carries out electrochemical oxidation reaction in alkaline electrolyte system;Reaction solution is removed inorganic impurities by anion exchange membrane separation, and then refined by acidification crystallization and vacuum sublimation, to obtain high-purity furfuryl acid.The application constructs "electrochemical oxidation-membrane separation-sublimation refining" coupling system, without additional chemical oxidant, by low-cost composite electrode optimization catalytic performance, combined with membrane separation and vacuum sublimation synergistic purification, solve the problems of low product purity, large wastewater discharge, high energy consumption in traditional process, meet the requirements of green chemical industry, and can be widely used in medicine, pesticide, high-end perfume and other fields.

The invention provides a preparation method of preserved citrus. The method comprises the following steps: cutting navel oranges or citrus peel residues into strips, and pre-cooking with a mixed solution of citric acid and a ginger extract; performing quick-freezing treatment on the precooked peel residues to form a directional micro-pore structure; performing vacuum sublimation treatment after quick freezing treatment; atomizing the composite sugar solution, and performing sugar permeation treatment on the raw materials after vacuum sublimation; performing curing treatment on the raw materials subjected to sugar permeation; and drying the cured raw materials to a target water content to obtain the preserved citrus. The method has the advantages that the residual sugar content on the surface is smaller than or equal to 0.1% and is reduced by 96% or above compared with 2.8% of a traditional process, and the sugar wiping procedure is completely omitted. According to the method, 'freezing-sublimation sugar crystal 'directional filling is adopted, internal ice crystals are formed through quick freezing, and directional micro-channels are reserved through vacuum sublimation; and the gas-phase mass transfer is realized, the sugar directly enters the pulp through the directional micro-pore channels, and'internal filling and no sugar hanging outside 'is realized, so that the liquid sugar liquid is fundamentally prevented from being attached to the surface. The sugar permeation time is shortened to 25-35 minutes from 8-12 hours in the traditional process, and the equipment turnover rate is increased.

The present application belongs to the technical field of BHET purification, and relates to a method for improving the yield of BHET after vacuum sublimation purification, wherein an inhibitor is added in the process of vacuum sublimation of raw materials containing BHET to inhibit the polymerization reaction of BHET, so as to improve the yield of BHET after purification; the inhibitor is bis-(3-methyl-1-imidazole) ethylene bis(bistrifluoromethylsulfonyl) imide, and the chemical structural formula is: compared with the case where no inhibitor is added, the yield of BHET after purification is increased by more than 13%. The method of the present application can not only improve the purity and yield of BHET after vacuum sublimation purification, but also reduce the energy consumption in the purification process to a certain extent.

The invention belongs to the technical field of high-purity metal preparation, and particularly relates to a method and device for preparing high-purity metal manganese through vacuum sublimation. The method comprises the following steps: pretreating a raw material manganese; carrying out vacuum sublimation and condensation treatment on the pretreated raw material manganese; the pretreatment comprises ultrasonic cleaning, surface chemical cleaning with diluted hydrochloric acid and vacuum drying; the target sublimation temperature of the vacuum sublimation is below the melting point of manganese, and the temperature of a condensation area of the condensation treatment is controlled to be 850-980 DEG C. According to the method, trace elements which are high in melting point and difficult to volatilize in the manganese metal can be effectively removed, the purity of a high-purity manganese sample reaches 5N, the total content of non-gas element impurities is lower than 10ppm, the total content of gas elements is lower than 50ppm, the purity of the manganese metal is remarkably improved, and the method has the advantages of being simple in technological process, low in energy consumption, high in product collection rate, free of pollution and the like.

This invention discloses an online self-cleaning and anti-contamination system and method for ceramic rollers used in vacuum coating of cadmium telluride photovoltaic glass. The system includes multiple high-temperature ceramic rollers arranged parallel to each other along the glass substrate transport direction. Each high-temperature ceramic roller is mounted at both ends to fixed supports on both sides of the main coating cavity of the equipment via bearings. The system also includes three synergistic components with closed-loop coupling feedback of thermodynamics and mechanodynamics, including a stator-side thermodynamic anti-sublimation shielding ring assembly located between the fixed supports and the ends of the high-temperature ceramic rollers. The purpose of this invention is to solve the problems in the vacuum sublimation coating production process of cadmium telluride photovoltaic glass, such as bearing jamming caused by the penetration and condensation of gaseous molecules at the ends of the high-temperature ceramic rollers, and transport instability caused by the hardening of solid deposits at the central support points. Furthermore, conventional physical cleaning methods require shutdown and vacuum breaking, severely restricting continuous production capacity.

The invention belongs to the technical field of BHET purification, and relates to a method for improving the yield of BHET after reduced pressure sublimation purification, an inhibitor is added in the process of reduced pressure sublimation of a raw material containing BHET to inhibit the polymerization reaction of BHET, so that the yield of purified BHET is improved; the inhibitor is bis-(3-methyl-1-imidazole) ethylidene bis (bis (trifluoromethylsulfonyl) imide, and the chemical structural formula of the inhibitor is shown in the specification. Compared with the method without adding the inhibitor, the yield of purified BHET is increased by 13% or above. The method provided by the invention not only can improve the purity and yield of BHET after vacuum sublimation purification, but also can reduce the energy consumption in the purification process to a certain extent.

This application relates to the field of radioactive waste treatment technology in the nuclear industry, and more particularly to a method for separating and recovering uranium-containing radioactive waste. This application employs a combined vacuum sublimation and cryogenic distillation process. First, vacuum sublimation is used to vaporize the mixed working fluid under reduced pressure and heating. Then, a multi-stage condensation system separates the solid UF6 / BrF3. The uncondensed gas is passed into a cryogenic device for liquefaction and recovery of Br2. Finally, utilizing the vapor pressure difference between UF6 and BrF3, gradient depressurization distillation is used to achieve efficient purification of UF6 and BrF3. This application, through a fully sealed process design, avoids radioactive leakage and generates no secondary solid waste. The UF6 purity is ≥98.8%, making it suitable for the treatment of radioactive hazardous waste from uranium enrichment plants and the resource recovery of similar mixtures.

The invention relates to the technical field of freeze drying, in particular to a circulating air freeze drying method and system.The method comprises a freezing procedure, a vacuumizing sublimation drying procedure and a frost melting procedure, and the three procedures are conducted in sequence: a refrigeration assembly and a circulating fan are started, and air flow is driven to be forcibly circulated between a ventilation pipeline and a cold trap to complete material freezing; stopping working of the circulating fan, and starting a vacuum assembly to vacuumize the interior of the cold trap to a preset vacuum degree, so that frozen ice in the dried object sublimates and forms a frost layer on the inner wall of the cold trap; and after defrosting is completed, the refrigerating assembly and the vacuum assembly are closed, the circulating fan and the heating assembly are started synchronously, and closed circulating airflow is formed between the ventilation pipeline and the cold trap through heated hot airflow for defrosting. Forced circulation of airflow in the cold trap is achieved, the heat exchange efficiency of the inner wall of the cold trap is improved, meanwhile, closed automatic frost melting is achieved, frost melting energy consumption is reduced, and the system structure adapts to the vacuum sealing and high-low temperature working environment requirements of the cold trap.

This invention relates to the field of microalgae functional component preparation, and particularly to a method for preparing DHA from Schizochytrium based on pH-responsive microcapsules and its spray freeze-drying preparation system, by constructing sodium alginate / Ca 2+ The cross-linked inner layer and the chitosan outer layer grafted with pH-sensitive groups are double-encapsulated, and combined with synergistic processes such as nano-atomization, liquid nitrogen quenching and vacuum sublimation drying, the problems of easy oxidation and inactivation of Schizochytrium DHA microcapsules, non-targeted release from the gastrointestinal tract and long cycle and low efficiency of traditional freeze-drying processes are solved.

The invention provides a material treatment method based on electrothermal vacuum sublimation and application of the material treatment method, and relates to the technical field of material synthesis and treatment technologies. The treatment method comprises the following steps: sequentially carrying out freezing treatment, vacuumizing treatment and electric heating treatment on a water-containing material to obtain a treated material. According to the material treatment method based on electrothermal vacuum sublimation, through three-stage cooperative control of freezing, vacuum and electric heating, integrated operation of four functions in a single device is achieved for the first time, and various nanoparticles such as silicon, platinum, nickel and sodium chloride can be efficiently prepared; carbon and water can be driven to react for in-situ synthesis of carbon monoxide and hydrogen; oxygen-containing functional groups of materials such as graphene oxide can be removed; rapid low-loss drying of fragile porous materials such as graphene aerogel and MXene aerogel can be completed; the integrated design greatly improves the function density and process compatibility of the equipment, and meets the multifunctional requirements of laboratory research and development and large-scale production.

The invention belongs to the field of synthesis of nano materials, discloses a large-scale preparation process of zero-dimensional perovskite nanocrystals, and aims to solve the technical problems that an existing liquid phase method is complex in process, difficult to scale and poor in product purity and optical performance. The preparation method comprises the following steps: mixing a precursor with a core-shell structure with a dynamic functional solvent containing a temperature-sensitive phase separation eutectic solvent and a sublimable solid template, reacting in a continuous mechanical force chemical reaction device with multiple temperature zones, and coupling mechanical energy with a thermal field to obtain the temperature-sensitive phase separation eutectic solvent. The generation and size confinement of the nanocrystal and in-situ surface passivation guided by temperature-triggered phase separation are realized in sequence; and finally, the template is removed through vacuum sublimation to finish purification. According to the method, a plurality of steps are integrated, the process is simplified, the method is green and free of waste liquid, continuous and large-scale preparation of the high-quality nanocrystalline is achieved, and the product has high crystalline phase purity, uniform and controllable particle size and excellent optical performance.

The invention relates to the technical field of magnesium metal purification, in particular to a method for removing iron-rich impurities in magnesium based on titanium mesh and silicon particle composite filtration, which comprises the following steps: S1, cleaning and drying a graphite piece; s2, assembling the dried graphite piece, the raw material coarse magnesium, the titanium mesh and the pure silicon particles to form an assembly, and putting the assembly into a furnace body; s3, the industrial electrolytic crude magnesium is heated under the vacuum condition; and S4, after heating is stopped, the furnace is cooled to the room temperature, and the product crystal magnesium is obtained. According to the method, high-temperature vacuum sublimation is conducted on industrial electrolytic coarse magnesium under vacuum, iron atoms and iron-rich particles in magnesium steam are adsorbed and intercepted by adding a titanium mesh and silicon particle composite filter material, efficient removal of impurity iron is achieved, meanwhile, the titanium mesh and the silicon particles are high in melting point and resistant to high temperature and cannot react with the magnesium steam, and new impurities cannot be brought to a system.