110 results about "Distillation method" patented technology

The invention provides a production method of high-purity sponge titanium. The production method comprises the following steps: firstly, obtaining refined magnesium and refined titanium tetrachloride after secondary refining; then feeding the refined magnesium and the refined titanium tetrachloride into a reactor subjected to titanizing treatment, and carrying out reduction and vacuum distillation in a protective atmosphere by adopting a reduction distillation method to obtain a sponge titanium lump; and finally, the sponge titanium lumps are subjected to surface impurity material stripping, then temperature-controlled crushing and screening are conducted, four-stage sorting including color sorting, magnetic sorting, winnowing and manual sorting is conducted, and the high-purity sponge titanium is obtained. According to the method, the refined titanium tetrachloride is used for purifying the crude magnesium, so that the high-purity production raw material is obtained; in the magnesiothermic reduction vacuum distillation process of titanium tetrachloride, a blocking method of impurities of Fe, Cr and Ni is adopted, and a pure sponge titanium lump is obtained; and identifying and separating high-iron, high-chlorine, high-oxygen and high-nitrogen impurity materials in the sponge titanium by adopting sorting methods such as color sorting, winnowing, screening, magnetic separation and the like to finally obtain the high-purity sponge titanium.

The invention discloses a rectification method for efficiently producing high-purity methanol by using low-temperature heat. According to the technology, a pressurized tower and an atmospheric tower are connected in parallel, so that crude methanol from a pre-tower kettle enters the two towers in a split-flow manner, low-temperature heat is used for supplying heat, and steam at the top of the pressurized tower serves as a heat source of a reboiler of the atmospheric tower; a tower section heat exchanger which can be flexibly arranged is arranged in the vacuum tower to utilize low-temperature heat; and thirdly, a recovery tower is changed into a vacuum tower, and low-temperature heat is used as a heat source of a reboiler. The technology can be flexibly implemented partially or completely, and a remarkable energy-saving effect can be achieved. The embodiment shows that the technology can stably produce high-precision methanol with the ethanol content as low as 10 ppm or below, the fresh steam consumption per ton of methanol is reduced to 0.2 ton or below, the productivity of the device can also be improved, and compared with a traditional four-tower double-effect rectification technology (the ethanol content is about 50 ppm, and the fresh steam consumption per ton of methanol is 1.0-1.2 tons), the technology has remarkable advantages in the aspects of product purity reduction and energy consumption reduction. The method effectively solves the problems of difficult production of high-precision methanol, high energy consumption and insufficient utilization of low-temperature heat in the prior art, and has good economic and environment-friendly benefits.

The continuous production heat pump assisted integrated extractive distillation device is adopted to realize high-purity separation and recovery of the diethyl ether-methyl formate-n-pentane azeotrope, and separation is realized by utilizing the characteristic that the extraction agent has great influence on the relative volatility of the diethyl ether-methyl formate-n-pentane azeotrope. The purity of the separated diethyl ether, n-pentane and methyl formate reaches 99.9% or above, high-purity recycling of the extraction agent can be achieved, the separation cost is greatly reduced, and the method is low in energy consumption and flexible to operate.

A distillation method includes supplying a batch type distillation column with a liquid that is a process fluid; increasing pressure and temperature of a fluid, with a compressor and supplying the fluid to a reboiler; exchanging heat in the reboiler between the liquid, which has been supplied to the distillation column, and the fluid, which has been increased in pressure and temperature, to heat the liquid and acquire overhead vapor and to condense the fluid; delivering the overhead vapor to a condenser and condensing the overhead vapor into a condensate through heat exchange, removing the condensate; removing residual liquid from the distillation column; and regulating pressure of the distillation column to distill the liquid with heat generated by a heat pump operated over a narrower temperature rising range in the pressure-temperature increasing step.

The invention relates to the technical field of distillation, in particular to a distillation device for production and collection of triisopropyl borate and a distillation method.The distillation device comprises a distillation device body, the distillation device body comprises a distillation retort, the distillation retort comprises a retort body and a cover body internally provided with a rotating core structure, and the rotating core structure is composed of a mixing component and a guiding component which are coaxially connected; the mixing part is of a hollow spiral structure, and the guiding part is of a solid spiral structure. Heat generated by the spiral heating pipe in the wall of the tank body and the annular heat-conducting oil disc at the bottom can be quickly conducted into materials in the distillation cavity through a through heat conduction channel in the hollow mixing screw piece, the drainage screw piece rotates to drive the heated gaseous materials to form a spiral ascending flow field, and the spiral ascending flow field is formed by combining an umbrella-shaped flow guide cover; steam can be directionally guided to a gas state conveying opening, and disordered diffusion and reverse mixing of the steam are reduced; in addition, the raw materials directly enter the gas-liquid balance area through the middle feeding port, and the back-mixing probability is further reduced.

This invention relates to the field of separation and purification, and particularly to a distillation method for Forsythia suspensa volatile oil, comprising the following steps: Step (1) Crush dried Forsythia suspensa fruit and mix it with water at a mass ratio of 1:3-5, grinding until the particle size D90≤50μm to obtain Forsythia suspensa slurry; Step (2) Add porous medium A particles with a particle size of 0.5-1mm and water-absorbing medium B to the Forsythia suspensa slurry obtained in Step (2), stir and mix for 20-40min to obtain a cake; Step (3) Mix the cake with moistened porous medium C particles with a particle size of 1-3cm, then load it into a distillation kettle for distillation, collect the distillate and separate to obtain Forsythia suspensa volatile oil. This scheme optimizes the distillation process, improves distillation efficiency, and solves the clogging problem caused by excessively fine grinding of raw materials, thereby meeting the industrial production demand for efficient and stable extraction of Forsythia suspensa volatile oil.

This invention discloses a method for preparing high-purity Si-75, comprising: S1, adding sodium sulfide, sulfur, and deionized water in a molar ratio of 1:(1.0~1.1):(5~8) to a reaction vessel, adding a buffer, and reacting at 80~90℃ for 1~2h; S2, adding a phase transfer catalyst and a hydrolysis inhibitor to the system, adding γ-chloropropyltriethoxysilane dropwise, and reacting at 85~95℃ for 3~5h, allowing the mixture to stand and separate into layers after the reaction, to obtain an organic phase; S3, subjecting the organic phase to short-path distillation and then filtering to obtain high-purity Si-75. Compared with existing technologies, this invention uses a phosphorus-free buffer system, which simplifies waste treatment. It uses water as the reaction medium and does not use large amounts of organic solvents, making it suitable for continuous industrial production. By adding hydrolysis inhibitors, hydrolysis can be effectively prevented during the reaction, increasing safety. The short-path distillation method provides high purification efficiency and can quickly remove impurities. The product has a disulfide content of ≥98.5% and a color of 0 (Gardner color number), which is of great significance to the light-colored rubber industry.

The application provides a purification method and dichloroisocyanurate obtained by using the method. The purification method of dichloroisocyanurate comprises the following steps: repeatedly crystallizing crude dichloroisocyanurate obtained in a production synthesis process to obtain purified dichloroisocyanurate. The purification method of dichloroisocyanurate of the application utilizes the different melting points of dichloroisocyanurate and other impurities, and is designed to be repeatedly crystallized at different gradient temperatures. By adjusting the crystallization temperature and the crystallization time, the impurities in the dichloroisocyanurate can be removed. Compared with the crude distillation method, the obtained dichloroisocyanurate has higher purity, and is safer and easier to operate.

The embodiment of the present application belongs to the technical field of seawater desalination, and particularly relates to a seawater distillation module, a seawater distillation device, a seawater distillation system and a distillation method. The seawater distillation module comprises a material liquid layer, an air gap layer, a gas permeable layer and a condensation layer. The material liquid layer has an inlet liquid side for guiding seawater to enter and an outlet liquid side for guiding seawater to flow out. The air gap layer is arranged opposite to the material liquid layer. The gas permeable layer is arranged between the material liquid layer and the air gap layer, and is used for separating the material liquid layer and the air gap layer. The gas permeable layer is used for allowing the seawater in the material liquid layer to pass through after being heated, and enter the air gap layer. The condensation layer is used for condensing the water vapor entering the air gap layer, so as to produce fresh water. Compared with the prior art, the seawater distillation device can meet the production of fresh water in island reef areas.

The application discloses a distillation device and method for nitric acid purification, and relates to the technical field of nitric acid distillation.The distillation device for nitric acid purification comprises a device frame, a motor is fixedly installed above the device frame, an exhaust pipe is fixedly installed on the circumferential surface of the device frame, a feed pipe is fixedly penetrated through the circumferential surface of the device frame, an air outlet pipe is fixedly penetrated through the circumferential surface of the device frame, a condenser pipe is fixedly installed in the device frame, and the device frame is internally provided with a rotating rod, a connecting pipe, a rotating shaft, a fan blade, a convex plate, a supporting block, a connecting plate, a sleeve, a circular plate, an arc block, a supporting plate and an arc plate.The rotating rod is fixedly installed at the output end of the motor, the connecting pipe is fixedly installed in the device frame, and the rotating shaft is rotatably installed on the circumferential surface of the connecting pipe.The distillation device for nitric acid purification realizes the up-and-down movement of the fan blade while rotating, prevents the internal stratification of nitric acid, and causes incomplete distillation.

The embodiment of the invention relates to the technical field of low-temperature rectification, in particular to a low-temperature rectification system and a low-temperature rectification method.The system comprises a condensation part used for conducting gas-liquid separation on tower top process materials and conveying liquid materials to a reboiling part, and steam is conveyed to a first heat regeneration part; the first heat regeneration part and the second heat regeneration part are used for heating the steam to a preset temperature; the compression assembly is used for compressing steam and conveying the steam to the reboiling part and the first heat exchange part; the reboiling part is used for heating the liquid material to gasify the liquid material and conveying the gas material to the condensing part; the first heat exchange piece is used for heat exchange of steam; the first heat exchange piece and the reboiling piece are used for conveying liquid materials into the first heat return piece to be cooled, and the circulation driving piece is used for circulating the materials to the condensation piece. According to the low-temperature rectification system, heat can be provided for the reboiling part, the energy consumption of the reboiling part is reduced, cold energy can be provided for the condensation part, the energy consumption of the condensation part is reduced, and then the energy consumption of the whole low-temperature rectification system is reduced.

This invention discloses an energy-saving five-tower methanol distillation method based on multi-effect thermal coupling. Crude methanol is fed to a pre-tower for distillation; the bottom product of the pre-tower is fed to an atmospheric distillation tower, the bottom product of the atmospheric distillation tower is fed to a negative pressure distillation tower, and the bottom product of the negative pressure distillation tower is fed to a pressurized distillation tower; the bottom product of the pressurized distillation tower is fed to a secondary pressure distillation tower; refined methanol is collected from the tops of the pressurized distillation tower, the atmospheric distillation tower, the negative pressure distillation tower, and the secondary pressure distillation tower; the top product of the pressurized distillation tower heats the reboiler of the secondary pressure distillation tower, and the top product of the secondary pressure distillation tower heats both the reboilers of the pre-tower and the atmospheric distillation tower; the top products of the pre-tower and the atmospheric distillation tower heat the reboiler of the negative pressure distillation tower. This process improves the heat recovery efficiency within the system, significantly reduces the condensation load of the top vapor, lowers the overall energy consumption of the distillation process, and achieves efficient multi-stage heat recovery and utilization within the system, reducing the ethanol content in the refined methanol product and improving methanol recovery efficiency.

The invention discloses a preparation method for continuous production of phosphorus trifluoride, and belongs to the technical field of chemical synthesis, and the key point of the technical scheme is that the preparation method for continuous production of phosphorus trifluoride comprises the following preparation steps: S1, adding phosphorus trichloride into the upper part of a rectifying tower, adding anhydrous hydrogen fluoride gas into the lower part of the rectifying tower, and stirring; contacting the two raw materials on the surface of the rectifying tower filler to complete reaction; s2, a product obtained through reaction is discharged from the top of the rectifying tower and enters a purification system, and phosphorus trifluoride is obtained.When phosphorus trifluoride is prepared through the rectifying method, the reaction process is stable, the temperature is easy to control, the gas-liquid contact area is large, the reaction is complete, the reaction speed is high, and large-batch production is facilitated.

A distillation device includes a batch type distillation column, a reboiler that heats and vaporizes liquid, which is a process fluid supplied to the distillation column, into vapor, a displacement compressor that draws in fluid for heating the liquid and increases the fluid in pressure and temperature, and supplies the fluid to the reboiler, a condenser that condenses overhead vapor of the distillation column into a condensate, a distillate withdrawal portion that removes the condensate condensed by the condenser, and a discharged liquid withdrawal portion that removes residual liquid from the distillation column. The compressor includes an actual volume flow rate regulation mechanism that varies an actual volume flow rate of the fluid, which is increased in pressure and temperature by the compressor, in accordance with a change in a required heating temperature of the reboiler during operation of the distillation device.

Title of the invention: Method for defrosting an air separation apparatus by cryogenic distillation. During the defrosting of an air separation apparatus by cryogenic distillation, defrosting gas is sent to a heat exchanger (15) and from the heat exchanger to the top of a column (21) via a line (C6) used in normal operation to draw nitrogen, entering the column, defrosting gas is drawn from the tank of the second column via a line and sent to the heat exchanger and then to the air, a flow of defrosting gas is sent to the top of another column via a line (C7) at a temperature above 0°C, defrosting gas is drawn from the other column via the line used in normal operation to send air to the other column, sent to the heat exchanger and sent to the air. Abstract figure: Fig. 2

This application discloses an automated distillation method and system for Maotai-flavor liquor based on dual-stillation collaboration, belonging to the field of Maotai-flavor liquor brewing technology. The method is implemented using a system with a dual-stillation shared detection module, an intelligent decision-making module, and a valve island control execution module. It includes first calibrating the alcohol content thresholds and process parameters for the heads, main body, and tails of the liquor according to the brewing cycle; then completing system self-checks such as pipeline cleaning and sensor calibration; scheduling dual-stillation operations based on the distillation time difference; collecting liquor parameters in real time; automatically completing the graded distillation and path switching for the heads, main body, and tails; determining distillation termination based on alcohol content and duration; supporting rotation of dual-stillation detection stations; and finally, resetting the system and archiving data. This technical solution achieves full automation and standardization of the distillation process, improves the yield and quality stability of high-quality liquor, reduces hardware investment and labor costs, avoids the subjective errors and timeliness issues caused by manual operation, and is suitable for large-scale dual-stillation production of Maotai-flavor liquor.

The present disclosure provides an equipment for production of butanol and octanol and a triple-effect distillation method, comprising two processes: butanol separation and octanol separation, both processes use same feedstocks to obtain n-butanol, iso-butanol and octanol products through different procedures, respectively, wherein butanol separation process is sequentially divided into hydrogenation, removal of light and heavy components and separation of isomeric; and octanol separation process is sequentially divided into separation of isomeric, hydrogenation and removal of light and heavy components; the removal of light and heavy components for butanol is carried out by a butanol pre-distillation column and a butanol distillation column, and the separation of isomeric for butanol is carried out by a first butanol isomer column and a second butanol isomer column; and the separation of isomeric for octanol is carried out by a first butyraldehyde isomer column and a second butyraldehyde isomer column.

The present invention relates to the technical field of chemical metallurgy, and provides a method for preparing and purifying high-purity vanadium sponge. The method comprises: preparing a vertical vacuum reduction furnace, adding a reducing agent thereto, removing air from the furnace and introducing a protective gas thereinto; performing heating, adding vanadium chloride, then performing smelting, and after removal, placing same into a distillation furnace for heating and temperature-holding treatments; and finally, placing a product into a crucible in an electron beam furnace, performing evacuation, heating same to perform smelting, introducing a protective gas into the electron beam furnace after smelting, and cooling same to room temperature, so as to obtain a vanadium sponge product. In the present invention, high-purity vanadium sponge is prepared from a chloride of vanadium by means of a new metallothermic reduction-distillation method, and is further purified by means of vacuum electron beam refining. Therefore, the common technical problems of a long process, a low product purity, etc., during the preparation of high-purity vanadium metal by means of traditional methods are solved.

The present invention relates to the technical field of brewing and distillation equipment, and discloses a distillation equipment and a distillation method for whisky brewing. The distillation equipment for whisky brewing includes a base. A preheating kettle and a cooling tower are arranged in the middle of the base. A right distillation kettle and a left distillation kettle are respectively arranged on both sides of the base. A first pipeline mechanism is further arranged on the base. The first pipeline mechanism includes a perfusion pipeline arranged on the preheating kettle. Both the right distillation kettle and the left distillation kettle are communicated with the preheating kettle through the perfusion pipeline. A first series kettle pipeline is arranged on the left distillation kettle. The left distillation kettle is communicated with the right distillation kettle through the first series kettle pipeline. A second series kettle pipeline is arranged on the right distillation kettle. The distillation equipment and the distillation method for whisky brewing utilize the temperature of the raw liquor in the preheating kettle for condensation, and at the same time utilize the raw liquor to preheat the raw liquor in the preheating kettle, can directly produce liquor in one distillation, improve the energy utilization efficiency, and improve the liquor yield.

The present invention relates to a detection method for volatile oil of Bupleurum chinense DC. The detection method of the present invention includes the extraction of volatile oil of Bupleurum chinense DC. and the detection by gas chromatography. Among them, the extraction of volatile oil of Bupleurum chinense DC. uses the steam distillation method; gas chromatography is used to qualitatively analyze the chemical components of the volatile oil of Bupleurum chinense DC., and 18 compounds are identified.

The invention belongs to the technical field of perfume extraction, and particularly relates to a method for subcritical extraction of spearmint essential oil and application of the spearmint essential oil, the extraction method comprises the following steps: drying spearmint whole herb, crushing, adding spearmint whole herb powder into a subcritical extraction tank, using propane as an extraction agent, and collecting subcritical extraction fluid; adding the collected subcritical extraction fluid into an evaporation tank, and carrying out reduced pressure evaporation to obtain spearmint extract; and carrying out molecular distillation on the obtained spearmint extract, and collecting light components to obtain the spearmint essential oil. The subcritically extracted spearmint essential oil is purified by adopting a molecular distillation method, component separation of the spearmint essential oil can be realized at a relatively low temperature, and high-purity and high-quality spearmint essential oil is obtained while natural aroma components of the spearmint essential oil are reserved.

The application provides a method for determining the Re-Os isotope of chromite, comprising the following steps: weighing the chromite sample and adding it into a Carius tube; transferring the accurately weighed mixed diluent to the Carius tube under a refrigerated condition by using HCl; after freezing, adding HNO3 and H2O2 into the Carius tube in sequence and continuing to freeze, wherein the volume ratio of HNO3, HCl and H2O2 in the Carius tube is 4:4:1; after the Carius tube is closed, it is placed in an oven for heating for a preset time to dissolve the sample; the Re and Os in the sample solution are separated by using a direct distillation method; and the Re in the residual solution after distillation and the Os in the distillation absorption solution are enriched and purified, and high-precision Re-Os isotope determination is performed. The method has a lower overall process blank, can ensure high-precision analysis of chromite samples with extremely low Re content, and reduces the problems of Os cross contamination and sample loss.

The present invention discloses a highly efficient condensation and distillation device for rose oil and a distillation method, belonging to the technical field of rose oil preparation. The present invention comprises a distillation cylinder for heating a solution, wherein the upper end of the distillation cylinder is fixedly connected to a gas transmission pipe, and the upper end of the gas transmission pipe is fixedly connected to a heat exchange pipe via a connecting pipe, and a condenser pipe is provided on the inner side of the heat exchange pipe, and a circulating refrigeration pipe is connected to the outer side of the heat exchange pipe; the upper end of the condenser pipe is connected to the gas transmission pipe, and the condenser pipe and the heat exchange pipe are telescopically connected, and a steam driving member for driving the condenser pipe to be raised and lowered is provided on the inner side of the connecting pipe; the lower end of the heat exchange pipe is fixedly provided with a discharge pipe, and the upper end of the discharge pipe is elastically and telescopically connected to a support pipe. The highly efficient condensation and distillation device for rose oil and the distillation method can reciprocate the condenser pipe, improve the condensation effect and liquid recovery rate inside the condenser pipe, and can automatically clean the condenser pipe during use to ensure a long-term heat exchange effect.

The invention discloses an energy-saving process for separating ethanol from water by coupling extractive distillation and pervaporation in ethylene glycol side draw, and relates to the technical field of chemical separation and purification. Compared with a traditional distillation method, the pervaporation energy consumption is reduced by 30%-50%, high temperature and high pressure are not needed, and energy conservation and consumption reduction are achieved; the concentration of inhibitory components (such as butanol) in fermentation liquor is reduced through membrane separation, the overall yield is improved, and the inhibition effect is reduced; the method can be expanded to separation of other low-boiling-point substances (such as benzene-ethanol), the regulation and control range of process parameters (temperature and pressure) is wide, and the process is flexible; the equipment cost is reduced: three-component separation can be completed by a single tower, and the investment of double-tower equipment is reduced; energy consumption optimization: the energy consumption is reduced by accurately controlling the side line extraction position and the operation condition; impurities can be removed synchronously, and the product purity is improved.

According to an example aspect of the present invention, there is provided a method of removing volatile compounds from a lignin-containing material, the method comprising: providing a material comprising lignin and volatile compounds; treating the material by a distillation method in order to vaporize at least a part of the volatile compounds.

The present invention discloses a multi-stage continuous separation and recovery method for a mixed solvent containing explosives. By adopting a multi-stage short-range / molecular distillation method, the heating temperature is controlled at a relatively low temperature and the heating time is controlled within 2 minutes. There is no need to store a large amount of material, and safety accidents caused by solvent decomposition caused by high temperature and explosive explosion are effectively avoided. The method can realize the step-by-step recovery of multi-component solvents, effectively meet the reuse requirements of the recovered solvents, and is suitable for the recovery and separation of complex solvent systems.

The embodiment of the invention relates to the technical field of low-temperature rectification, in particular to a low-temperature rectification system and a low-temperature rectification method, and the low-temperature rectification system comprises a condensing device which is arranged to accommodate a refrigerant and a process material, and condenses the process material by using the refrigerant; the heating device is arranged to heat the gasified refrigerant and then convey the refrigerant to the reboiling device and the heat exchange device; the reboiling device is used for heating a liquid material to form a gas material and conveying the gas material to the condensing device; the heat exchange device is used for exchanging heat to obtain a liquid refrigerant; the heating device is arranged to convey the liquid refrigerant to the expansion device, the expansion device expands the refrigerant, and then the refrigerant is conveyed to the condensing device. According to the low-temperature rectification system provided by the embodiment of the invention, heat can be provided for the reboiling device, the energy consumption of the reboiling device can be reduced, cooling capacity can be provided for the condensing device, the energy consumption of the condensing device can be reduced, and then the energy consumption of the whole low-temperature rectification system is reduced.

Title of the invention: Method for starting an air separation apparatus by cryogenic distillation. In a method for starting an air separation apparatus by cryogenic distillation, the apparatus comprises a first column (3) operating at a first pressure and a second column (5) operating at a second pressure lower than the first pressure. The second column has a tank vaporizer (4) connected to be heated by a nitrogen-enriched gas from the first column, and means for delivering an oxygen-enriched fluid to the tank of the second column, connected to a heat exchanger (6) to ensure the heating of the oxygen-enriched fluid. To start the apparatus, air is sent to the first or second column, and then liquid nitrogen is sent below the vaporizer from an external source (1). Abstract figure: Figure 1

The separating device comprises a separating tank, a steam pipeline and an upper clamping plate, one side of the upper end of the separating tank is communicated with a liquid inlet pipeline, one side, far away from the liquid inlet pipeline, of the separating tank is communicated with a water outlet pipeline, the liquid inlet pipeline is distributed at the upper end of the water outlet pipeline, a through hole is formed in the middle of a heating disc, and the steam pipeline is communicated with the upper clamping plate. And the bottom of the through hole communicates with a waste liquid conveying pipeline, and an upper clamping plate is erected in the separation tank. When the separating device for alcoholic fermentation is used, alcohol and mixed liquid are separated by adopting a distillation method, when the steam pipeline heats the mixed liquid to a position between the boiling point of the alcohol and the boiling point of water (such as 78-100 DEG C), the alcohol is vaporized into steam, substances with higher boiling points, such as water, are still left in a liquid phase, and the vaporized alcohol steam is cooled by the condensing pipe and then is separated from the mixed liquid. Therefore, the high-concentration alcohol solution is separated from other substances, and the requirement for separating the alcohol from the mixed liquid is met.

To provide a molecule removal method and a molecule removal device that can remove molecular components of which removal is difficult by only a molecular distillation method.SOLUTION: A molecule removal method for removing molecule components from a base oil has: a process (a) in which in the state that a container, in which there are the base oil and a stirrer located in the base oil, is arranged in a chamber, the interior of the chamber is evacuated; and a process (b) in which in the state that a pressure in the chamber becomes less than 1 mPa by evacuation, the stirrer is rotated to stir the base oil.SELECTED DRAWING: Figure 1