281 results about "Separation problem" patented technology

The invention provides a method for separating magnesium from lithium and extracting the lithium from high magnesium-lithium ratio brine (brine from a saline lake, from underground and from an oil-gas field). The method comprises: sodium salt and potassium and magnesium mixed salt are separated from the brine by evaporation of a saltpan; after boron extraction, sodium hydroxide is used for precipitating Mg<2+> from obtained old brine, and crystallized Mg(OH)2 is obtained by modification and precipitation condition control; filtration and separation are carried out to remove the Mg(OH)2 to realize separation of magnesium and lithium; after filtered mother solution is vaporized and concentrated for 2-4 times, Na2SO4 and NaCl are separated by crystallization, and pure caustic soda can be added to form lithium carbonate from lithium; or the operation of further evaporation is carried out until Na2SO4 and NaCl are separated by multiple times of natural evaporation or forced evaporation concentration and multiple times of cooling crystallization; the operations of evaporation and concentration are carried out until LiCl saturation, and LiCl products can be prepared after the operation of cooling crystallization is carried out. Compared with the prior art for separating the magnesium from the lithium and extracting the lithium from the brine, the method obtains the crystallized Mg(OH)2 by modification and precipitation condition control, solves the existing technical problem of hard filtration of Mg(OH)2, solves the defects of high energy consumption, complex process and high cost of the existing calcination method, and solves the fundamental defects of low Li<2+> recovery ratio and complex technical process of the traditional precipitation method. The Li<2+> recovery ratio ranges from 85-93%, Mg<2+> removal ratio is more than 99.5%, and the method solves the problem of extracting Li<+> and Mg<2+> from high-magnesium and low-lithium brine with Mg<2+> / Li<+>>=20 mass ratio.

The invention relates to a method for preparing manganese sulfate. The method comprises the following steps: quantitatively adding sulfide with reducibility into a manganese dioxide ore in a reaction molar ratio for sufficient reaction, determining a reaction end point, and separating and washing a solid-phase resultant; reacting the solid-phase resultant with 9 to 12mol / L H2SO4, controlling the reaction end point to the pH of between 3 and 5, controlling the concentration of MnSO4 in the reaction liquid in a range of between 300 and 400g / L, performing solid-liquid separation after the reaction is completed; acidizing the separated solution by H2SO4 until the pH value of the solution is between 2 and 3, adding hydrogen peroxide into the solution and heating the mixture, precisely filtering and removing the part of solid phase; and distilling, concentrating, crystallizing and dehydrating the filtrate to prepare the manganese sulfate. The method can prepare acid soluble manganous oxide and ensure that various heavy metals can generate insoluble sulfides so as to solve the problem of completely separating heavy metals and obtain the manganese sulfate with low calcium magnesium and low heavy metals.

The invention provides a method for separating and preparing hydrogen by decomposing water in a fuel cell through photocatalysis according to the inverse principle of the hydrogen fuel cell, aiming to avoiding the current separation problem of hydrogen and oxygen prepared by decomposing water through solar energy photocatalysis. The method adopts the inverse principle of the hydrogen fuel cell and uses photocatalyst as raw material for a photoanode, and platinum, nickel or carbon electrode as a cathode; an ion film is used between the two electrodes to transfer protons or hydroxyl ions, circuit is formed by connecting the photoanode and the cathode with a lead; sunlight or simulated sunlight is used as a light source, the light directly shines down upon the photoanode; and hydrogen is generated on the cathode and an oxidation reaction is performed on the anode so as to realize the aim of separating and preparing hydrogen by decomposing water through photocatalysis. In the method of the invention, no sacrifice agent or inhibitor is needed to add for adjusting the pH value of the electrolyte solution, an external power source can be added as additional bias so as to directly separate and prepare hydrogen by decomposing water through photocatalysis, and the separation problem of hydrogen and oxygen in practical technology development for decomposing water through solar energy photocatalysis is successfully solved.

The invention relates to the field of packaging equipment, in particular to a novel high-efficiency bag supply system. The novel high-efficiency bag supply system comprises a bag preparing system and a bag taking, feeding and pre-opening system. The bag preparing system plays a role in bag supply and is composed of a bag supply position and a bag temporary storing position. The bag preparing system further comprises a bag pushing cylinder and a bag preparing push rod. The bag taking, feeding and pre-opening system is used for separation of overlapped packaging bags, sorting and positioning of a single packaging bag and one-time pre-opening, and is composed of a bag taking mechanism, a position shifting system, a bag sorting mechanism, a positioning system and a one-time pre-opening system. According to the novel high-efficiency bag supply system, the overlapped bags in a bag preparing bank are separated in the mode that the packaging bags are taken from side faces; meanwhile, the position shifting system, the bag sorting mechanism and the positioning system are added. The problem of bag opening separation is solved since the bags are taken from the side faces; the bag sorting mechanism and the positioning system automatically sort and position the packaging bags respectively, the requirement for tidiness and uniformity of the packaging bags in the bag preparing bank is also lowered, as a result, labor intensity is mitigated for workers, and the success rate of bag supply is increased.

The invention provides an Open Flow protocol framework based on a mobile communication network, and relates to the field of mobile communication networks. The framework comprises a controller module, a resource pool module, a core network module, a service node module and a terminal module, wherein the control module, the core network module, the service node module and the terminal module are connected in sequence, and the controller module is connected with the resource pool module. The invention further provides a service separated processing method of the Open Flow protocol framework based on the mobile communication network. Based on the separation problem of different services in the mobile communication network, the purpose that the Open Flow protocol framework is applied to an Open RAN framework is achieved, and the mobile communication network is made to be more open and adaptive to different services to meet service requirements which are more and more complex in the network environment.

The invention relates to a preparation method of composite catalyst of the titanium silicate molecular sieve and the nano-carbon fiber. The composite catalyst of the titanium silicate molecular sieve and the nano-carbon fiber prepared by the method of the invention has strong bonding force between the active component of the titanium silicate molecular sieve and the nano-carbon fiber. Comparing with the industrial micro-nano TS-1 powder (100-500nm), the filtering quality is significantly improved. In the course of using the TS-1 catalyst, the problem of the solution dispersion and separation can be solved; the method is simple and the application range is wide. The catalytic performance of the made composite catalyst is excellent, and can be used for the cyclohexanone ammoximation, the conversion rate of the cyclohexanone and the cyclohexanone oxime selectivity can both reach over 98 percent.

The invention relates to a method for extracting and separating tungsten and molybdenum in a high-phosphorus mixed solution containing tungsten and molybdenum. The method comprises the following steps: adding hydrogen peroxide in the high-phosphorus mixed solution containing tungsten and molybdenum for acidity adjustment and control, and converting phosphotungstic acid and phosphomolybdic acid into peroxy-phosphotungstic acid and peroxy-phosphomolybdic acid; then, taking a mixture of tributyl phosphate (TBP) and methyl phosphate dimethyl heptyl ester (P350) as an extracting agent, extracting the peroxy-phosphomolybdic acid into an organic phase, and leaving the peroxy-phosphotungstic acid in an aqueous phase; from now on, after decomposing the peroxy-phosphotungstic acid in extraction raffinate in the way of heating or ultraviolet irradiation or introduction of sulfur dioxide, extracting tungsten in the solution again with a fresh mixed extracting agent, and finally realizing extraction and separation of tungsten and molybdenum from complex material liquid. The method is small in tungsten co-extraction loss, can effectively solve the extraction and separation problem of tungsten and molybdenum in the high-phosphorus mixed solution containing tungsten and molybdenum, and is easy to realize industrialization.

The invention discloses a matrix-transformation-based method for underdetermined blind source separation. The method comprises the following steps of: gradually transforming a mixed matrix to obtain a transformed matrix, then acting the transformed matrix on an observation signal to gradually remove each source signal, and constructing multi-stage binary shielding templates by zero points generated in each observation signal to gradually separate the source signal. By the method, the requirement on sparsity of the source signal is reduced; aliasing of at most M-1 paths of source signals is prevented (wherein M is the number of sensors); source signals for forming each time frequency point can be clearly known; the underdetermined separation problem of music signals and noise signals is solved; the statistical property requirement on the source signal is low; the underdetermined separation problem of Gaussian signals and related signals is solved; processing stages are adjusted according to the requirement of separation precision; when the processing level is more, the separation result is better; the separation process is realized by aid of the matrix transformation; and the complexity is relatively low.

The invention relates to an airfoil flow control device. The airfoil flow control device is arranged on the upper surface of the main airfoil of an airplane near the front edge of the airfoil. The device consists of a fundamental frequency Gershgorim band and a subharmonic frequency Gershgorim band which are arranged in parallel; both the fundamental frequency Gershgorim band and the subharmonic frequency Gershgorim band are in a sawtooth shape; during the taking off stage, a front flap extends the airfoil flow control device, thereby controlling the boundary layer of the airfoil to fast transit and form an onflow boundary layer used for restraining or eliminating the separation of the boundary layers, thereby effectively improving the life force of the airfoil; during cruising flying, the front flap of the airfoil resets to cover the device, thus leading the device to be out of use and leading the boundary layer of the airfoil to maintain a layer flow during the cruising stage, so as to reduce the friction resistance at the airfoil surface and improve the lift-drag ratio. The airfoil flow control device has the advantages of simple structure, light weight and convenient for being maintained, can solve the separation problem of the boundary layers of the airfoil surfaces during the taking off state of the airplane under the situations of not increasing the weight of the airplane and the power; besides, the airfoil flow control device also avoids the increasing problem of the friction resistance brought by the transition of the boundary layers of the airfoil surfaces during the cruising flying stage.

The invention relates to a method for separating an isobutyl alcohol and normal heptanes azeotropic system by using pressure swing distillation and a device applicable to the method. The device mainly comprises an atmospheric tower T1, a pressurized tower T2, a condenser C1, a condenser C2, a reflux drum D1, a reflux drum D2, a reboiler R1 and a reboiler R2, wherein the reboiler R1 and the reboiler R2 are respectively connected at the bottoms of the atmospheric tower T1 and the pressurized tower T2, the condenser C1 and the reflux drum D1 are sequentially connected at the top of the atmospheric tower T1, the condenser C2 and the reflux drum D2 are sequentially connected at the top of the pressurized tower T2. The separation steps are as follows: a fresh material first enters into the atmospheric tower T1, an isobutyl alcohol product is extracted at the bottom of the tower, after being condensed through the condenser C1, and collected through the reflux drum D1, part of overhead vapor is back flowed, part of the extract enters into the pressurized tower T2 for a secondary rectification, a normal heptanes product is extracted at the top of the pressurized tower T2, and the material flow at the bottom of the tower cycles to the atmospheric tower T1. The method provided by the invention solves the difficult separation problem that the azeotropic behaviors of the system respectively show up a lowest feature and a highest feature along with the raising pressure, and has the advantages of low energy consumption and high product recovery rate.

The invention discloses a multi-metal recycling method of electric furnace tin-smelting dust. The method comprises the following steps: electric furnace tin-smelting dust is placed in a reaction kettle, sulfuric acid or / and raffinate are added to perform neutral leaching so that metals such as zinc are leached in the neutral solution and indium, tin and lead are left in residues; the neutral residues are placed in a reaction kettle, concentrated sulfuric acid is added for cure leaching, cleaning solution is added after the reaction to ensure that indium and a part of tin are leached in the solution and most of tin and lead are left in residues; extractant P204 is used to extract the indium and tin of the leachate and separate indium and tin from zinc, hydrochloric acid is used to perform backextraction to the extract so that tin and indium can be separated from the organic phase through backextraction and high concentration indium-tin mixed backextraction solution can be obtained; tributyl phosphate (TBP) extractant is used to extract tin to obtain material solution with indium and material solution with tin; and the material solution with indium is replaced by using a zinc plate and casted to obtain crude indium, the crude indium is electrolyzed and purified to obtain a refined indium product. The method combines the mature concentrated acid curing technology, extraction technology and other technologies into a whole, solves the separation problem of indium and tin and ensures that various high-value metals in the electric furnace dust can be recycled efficiently, continuously and largely; and the actual indium yield is more than 80% and the purity of the refined indium is more than 99.93%.

The invention relates to an unmanned aerial vehicle longitudinal flight control system fault detection and separation method based on nonlinear adaptive observers. According to the invention, based onan unmanned aerial vehicle longitudinal nonlinear model, a set of nonlinear adaptive observers are designed for actuator and sensor faults of a longitudinal flight control system; a fault separationproblem is transformed into a model matching problem; by referring to the idea of a contribution analysis method, a fault estimation value and the fault direction, which are acquired by each adaptiveobserver, are used to contribute a contribution function, and standardization is carried out; the optimal matching model is determined by selecting the maximum standardized contribution function; andfinally, the maximum standardized contribution function is compared with a threshold value, and fault detection and separation results are acquired. According to the invention, a new reference index is provided for model matching by referring to the contribution analysis method; an analytical model is used to design the nonlinear adaptive observers to acquire a reliable fault estimation value andfault direction; and the problem that the fault direction is difficultly determined in a data driving method is overcome.

The invention relates to a single channel voice blind separation method based on computational auditory scene analysis. The method includes the following steps of firstly, conducting front-end processing on inputted aliasing voice; secondly, conducting auditory feature extraction on the aliasing voice processed in the first step; thirdly, conducting auditory division on the aliasing voice processed in the second step on the basis of the harmonic features; fourthly, conducting auditory reconstruction on the aliasing voice processed in the third step on the basis of the energy features; fifthly, conducting target voice reconstruction on the aliasing voice processed in the fourth step. Under the condition that noise exists, the problem of single channel aliasing voice separation can be well solved, the separated voice can be applied to the front end of the voice recognition, and the single channel voice blind separation method can have wide application prospect in the artificial intelligence field, the voice communication field and the voice signal enhancement field.

The invention discloses a method for treating waste water with organic modified bentonite. The method provided in the invention comprises the following steps: (1) molding organic modified bentonite through immobilization; (2) filling molded organic modified bentonite in an adsorption apparatus; (3) delivering waste water into the adsorption apparatus filled with organic modified bentonite at a certain flow velocity so as to allow the waste water and organic modified bentonite to fully contact for infiltration and adsorption, wherein, outflow liquid after above-mentioned treatment is purified waste water; (4) desorbing organic modified bentonite with a desorption solution after saturation adsorption is achieved and allowing organic modified bentonite to be regenerated and recycled. According to the invention, organic modified bentonite is molded through immobilization, and the flow velocity of inflowing waste water is controlled; therefore, the problem of solid-liquid separation of waste water and an adsorbent is overcome, effective penetration and diffusion of bentonite in waste water is achieved, and the goal that liquid pollutants reach the standard after treatment is realized.

The invention provides an elevation inversion method for geosynchronous orbit synthetic aperture radar interference. The method comprises the steps that step 1, GEO SAR is selected to obtain a track of interference data, and the interference data on the track are collected; step 2, GEO SAR imaging processing is conducted through a BP algorithm according to the interference data obtained in step 1; step 3, a GEO interference model is built according to the GEO SAR image processed in step 2, and when a phase position vector is separated from an imaging plane, the GEO SAR interference elevation inversion is conducted according to the GEO interference model. According to the elevation inversion method for the geosynchronous orbit synthetic aperture radar interference, due to the fact that the reasonable GEO SAR interference model is built, the effective elevation inversion processing under the condition that the phase position vector and the imaging plane are separated is achieved, the core problem of the elevation inversion of the GEO SAR interference processing, namely, the separation problem of the effective phase position vector and the imaging plane is solved, and the elevation inversion of the GEO SAR interference processing at any position is achieved.

The invention discloses a preparation method of a thickener used for self-compact concrete. The method comprises the following steps: 1, weighing 2-acrylamide-2-methylpropanesulfonic acid and acrylic acid in proportion, processing to prepare an aqueous solution, and adjusting the pH value to 6.5-7.0; 2, adding a prepared monomer acrylamide solution with the concentration of 25-35% while stirring, uniformly stirring, dumping the obtained mixed solution into a flask, carrying out constant temperature water bath, and introducing nitrogen for protection; and 3, adding an initiator in a dropwise manner when the reaction temperature rises to 30-40DEG C, carrying out heat insulation at 40DEG C, carrying out a stirring reaction for about 1.5-2h, stopping the introduction of nitrogen when reactants are a viscous liquid, and carrying out constant temperature slaking for a period of time to obtain a white transparent colloid which is the thickener. The thickener obtained in the invention is used for preparing the self-compact concrete, has a good water solubility and a good thickening effect, can effectively improve the plastic viscosity of the self-compact concrete, and solves the water segregation and separation problems of the self-compact concrete.

The invention discloses a formula of belted layer cushion rubber of an all-steel radial tire. The formula is characterized in that the cushion rubber comprises the following raw materials by weight parts: 100 parts of natural rubber, 20-40 parts of carbon black, 5-20 parts of white carbon black, 0.1-0.4 part of an environment-friendly peptizer, 0.5-2 parts of stearic acid, 3-7 parts of zinc oxide, 1-3 parts of a carbon black dispersant, 0.5-2 parts of an anti-ageing agent RD, 1.5-3 parts of an anti-ageing agent 4020, 1-7.5 parts of a silane coupling agent, 1-4 parts of tackifying resin, 0.5-2 parts of bonding resin, 1.5-3 parts of insoluble sulfur HIS7020, 1-2.5 parts of an accelerant NS, 0.1-0.4 part of a scorch retarder CTP and 1-3 parts of an adhesion promoter RA-65. According to the formula, the durability of the tire can be greatly improved, the high-load long-distance driving resistance of the tire in a using process is improved, shoulder separation problems are reduced, and the economic benefit is increased.

The invention provides a hot-mix cold-lay rubber asphalt mixture. The mixture is characterized in that: the mixture comprises rubber asphalt and an aggregate; the aggregate comprises a coarse aggregate, a fine aggregate and ore powder; and the rubber asphalt comprises the following components, by weight, 1.5-10% of rubber powder, 5-15% of solvent naphtha, 0.1-5% of a silane coupling agent, 2-5% of a thermoplastic elastomer, and the balance petroleum asphalt. The silane coupling agent, which is added to rubber powder modified asphalt in the invention, allows a separation problem of the rubber powder and asphalt to be effectively solved. The obtained hot-mix cold-lay rubber powder modified asphalt mixture can keep a good loosened state for several months and all performances are stable in normal temperature conditions.

The invention provides a multi-grade separating type electric heating device for taking out a cigarette conveniently, which comprises a heating cavity outer shell, a heating cavity inner shell, and aheating component; the heating cavity inner shell is encircled to form a heating cavity, and the heating cavity is used for holding a heated cigarette section; the heating component is located in theheating cavity and used for heating the cigarette section; the heating cavity inner shell is arranged at the inner part of the heating cavity outer shell, the heating cavity outer shell and the heating cavity inner shell are formed to be an integrated axial rotating whole body; the heating cavity outer shell comprises a first-grade heating cavity outer shell and a second-grade fixing rotating outer shell which are detachably connected; the whole heating cavity outer shell formed by combining the first-grade heating cavity outer shell and the second-grade fixing rotating outer shell can axiallyrotate around the electric heating device main body. The multi-grade separating type electric heating device can solve the problem of separating element from the low-temperature cigarette in the heating appliance; on the basis of the electric heating device specific to the rotational cigarette taking in axial direction, the rotating smoothness is improved, the smoke air flowing method is promoted, and the retention probability of the low-temperature cigarette at the heating cavity is effectively reduced.

The invention discloses a two-stage initiative separation method based on normalized spectral clustering and constrained spectral clustering. The method comprises the steps of: in the first stage, recognizing coherent generator groups by using normalized spectral clustering and forming pairwise constraints by using the coherent generator groups; and in the second stage, finding separation sections satisfying the pairwise constraints and with the minimum active power flow shock by using constrained spectral clustering. When a system needs to be separated into a plurality of islands, a recursive bisection method can be adopted. The algorithm provided by the invention takes two factors, i.e., generator coherency and the minimum active power flow shock, into account, and the initiative separation problem can be calculated in real time without simplifying system topology.

The invention discloses a head mounted type display device based on holographic waveguide. The head mounted type display device comprises inlet coupling grating (1), left visual field deflection grating (2), right visual field deflection grating (3), outlet coupling grating (4), and rectangular waveguide (5). The inlet coupling grating (1), the left visual field deflection grating (2), the right visual field deflection grating (3), and the outlet coupling grating (4) are attached to the upper surface or the lower surface of the rectangular waveguide (5). Whether the inlet coupling grating (1), the left visual field deflection grating (2), the right visual field deflection grating (3), the outlet coupling grating (4), and the rectangular waveguide (5) are attached to the upper surface or the lower surface is determined by an exit entrance pupil light design direction. By adopting a pupil remodeling way, a visual field separation problem of a conventional two-dimensional pupil dilation way under a large visual field angle condition is solved.

The invention relates to a method for treating non-acidic oxygenated organic substances in Fischer-Tropsch synthesis reaction water, which mainly solves the problem of separation and recovery of non-acidic oxygenated organic substances in Fischer-Tropsch synthesis reaction water. The method comprises the following steps: Fischer-Tropsch synthesis reaction water is subjected to (a) organic acid rectification separation, (b) ketol cutting rectification separation, (c) acetaldehyde refinement, (d) propanal acetone rectification separation, (e) acetone refinement, (f) propanal refinement, (g) anhydrous fusel separation, (h) alcohol-water separation, (i) aldehyde and ketone hydrogenation reduction, (j) ethanol refinement and (k) n-propanol refinement to finally obtain basic organic raw materials, including acetaldehyde, propanal, acetone, ethanol, n-propanol, mixed alcohols and the like. Compared with the prior art, the invention has the advantages of simple technical scheme, high recovery rate and the like, well solves the problem of separation of organic oxygenated compounds in the Fischer-Tropsch synthesis reaction water, and can be widely used in industrial production of non-acidic oxygenated organic substances from Fischer-Tropsch synthesis reaction water.

The invention is protogenesis potential flotation technology for lead and zinc sulfide. The invention uses the ore pulp protogenesis potential formed in each complex electrochemical reaction as the ore pulp potential criterion of sulfide selectivity floatation separation, the invention uses electrochemical action namely oxide-reduction reaction in ore milling-floatation ore pulp, through adjusting and controlling the ore pulp pH value, capturing agent and floatation time and so on traditional operation parameter, thus adjusts and control the ore pulp potential. The invention can upgrades the separation selectivity of ore; the metal reclaiming rate can reach over 5%; the system processing ability is upgraded to 30%.

The invention refers to type gas-liquid separation device including a barrel liquid room, at least a gas collecting room, at least a drain film, at least a hydrophil film and liquid collecting room. The drain film is between the liquid room and gas collecting room, there has no gas-liquid fixed inlet between the drain film and liquid room, there has a gas pipe on top of the gas collecting room; the liquid room connects with the hydrophil film and liquid collecting room; there sets a liquid outlet pipe in the liquid collecting room; there also may include the extendible film; the two films are flat films, the hole radius is 0-1000 , the thickness is 0.1-0.4mm; the films can also be hollow pipe with radius of 1-1.5mm inner and 1.5-3mm external.

The invention relates to a preparation method of a metal doped organic-inorganic composite SiO2 film, which is characterized by using siloxane as a precursor, carrying out hydrolysis under acid catalysis, adding ethanol solution of salt (alkoxide or nitrate) containing metal M into ice bath to synthesize metal doped organic-inorganic composite SiO2 sol, after film coating and drying, obtaining the metal doped organic-inorganic composite SiO2 film through firing under inert atmosphere. The composite SiO2 film effectively solves the problem of efficient separation of H2(He) / CO2 in the industrial gases (H2, CO2, O2, N2, CH4 and CO) and obviously improves the separation effect of H2(He) / CO2 through double effects of molecular sieving mechanism and adsorption. The composite SiO2 film has good application prospects in such environments containing water vapor and various mixed gases (H2, CO2, CO and CH4) as water gas shift reaction, methane steam reforming reaction and the like.

The present invention relates to epoxy ethane hydrating process to produce glycol. Unlike available technology, which needs several towers or several reactors and several reaction steps, the process of the present invention has the epoxy ethane hydrating reaction and the separation of glycol completed simultaneously in the reacting and rectifying tower, and thus has greatly simplified technological process, greatly lowered material / water ratio and epoxy ethane consumption, less side reactions and obviously raised glycol selectivity. The present invention has the features of low production cost and high glycol selectivity, and may be used in industrial production.

The invention provides a method for preparing cyclohexanone oxime by ammoximation of cyclohexanone. According to the method, 5.0-100 mu m of titanium silicalite molecular sieve is used as a catalyst, the reaction temperature is controlled by using an external circulation heating mode, and a reaction product and the titanium silicalite molecular sieve are separated in an external circulating filter. Compared with the prior art, the method has the advantages that the device investment is low, the separation problem between the catalyst and the reaction product can be better solved, the utilization rates of a molecular sieve and a reaction device can be improved, the reaction effect is better under the condition that the concentration of the catalyst is the same, the control is more stable, the overhauling of the device is easier, and the effective utilization rate of hydrogen peroxide can reach 90% or so.

The invention discloses a positive- and negative-sequence combined control method for a three-phase PWM current transformer when a power grid is imbalanced. The combined control of positive-sequence and negative-sequence currents is realized in a positive-sequence dq synchronous rotating reference frame, the control system is simplified, and the normal and stable operation of the PWM current transformer is ensured when the voltage of the power grid is imbalanced. To solve the problem of separation of positive-sequence and negative-sequence vectors of the power grid voltage, a novel positive-sequence and negative-sequence vector separation method in the positive-sequence dq synchronous rotating reference frame is provided such that only a primary positive- and negative-sequence voltage extraction module is needed, and a positive- and negative-sequence extraction module is omitted. For the inner-loop control of current, a PI+R type composite controller method is provided, and a resonant frequency of a resonance controller is configured to be 2[omega], so that zero steady-state error control for the negative-sequence component in the dq synchronous rotating reference frame is realized. Besides, in order to increase the response speed of the control system, a voltage feedforward control method is adopted according an output voltage and current vector model of the PWM current transformer, so that the dynamic performance of the control system is improved.

The invention discloses a method for measuring multi-phase flow. The method comprises the following steps of: 1, converting a measured time-domain signal to obtain a oil-gas-water three phase power spectrum; 2, separating oil water and gas water, fitting the oil-gas-water three-phase power spectrum by using the curve characteristics of a two-phase flow power spectrum so as to acquire corresponding oil-water power spectrum and a gas-water power spectrum; and 3, obtaining the actual flow rate according to the relationship of demarcated power spectrum integral area-flow rate or / and power spectrum center frequency-flow rate. Curve fit is adopted for separation, so the problem of separating oil, water and gas can be well solved, and the defects disturbing the measurement of the multi-phase flow for a long term are overcome. Multiple test measurement proves that the measurement error of two-phase flow is 5 to 10 percent, the error for three-phase flow is about 15 percent, and production requirement can be completely met.

A process for preparing etha nediol features that the hydrating reaction of epoxy ethane and the separation of ethanediol are performed in a single reactive rectifying tower. Its advantages are high selectivity and low cost.