31 results about "Sodium perborate" patented technology

A positive electrode lead paste for a high-capacity and long-service-life storage battery and a preparation method therefor. The formula of the positive electrode lead paste comprises lead powder, dilute sulfuric acid, water and additives. In parts by mass, the additives added to every 1000 parts of the lead powder comprise: 1-3 parts of sodium perborate; 0.5-2 parts of 4BS; 1-3 parts of antimony trioxide; 1-3 parts of tin pyrophosphate; 2-4 parts of a polyolefin; 2-4 parts of a conductive carbon material; and 1-1.5 parts of a polyester staple fiber. By adding tin pyrophosphate and the polyolefin in the positive electrode lead paste, the capacity of a lead storage battery can be effectively increased and the service life thereof can be prolonged; and tin pyrophosphate and the polyolefin can work synergistically, and the addition of the two together achieves a better effect.

The invention belongs to the technical field of organic synthesis, and particularly relates to a pyroxasulfone preparation method which specifically comprises the following steps: dissolving 3-(5-difluoromethoxy-1-methyl-3-trifluoromethyl-1H-pyrazol-4-ylmethylthio)-5, 5-dimethyl-2-isoxazoline serving as a raw material with a solvent, then adding a boron compound, finally dropwise adding hydrogen peroxide, and reacting at room temperature to obtain the pyroxasulfone. Reacting for several hours to obtain pyroxasulfone; the adopted boron compound is cheap and easy to obtain, so that the use of a transition metal catalyst is avoided, and the raw material cost is reduced; organic acid reagents with heavy odor are not used, waste water and solid waste are less, and the method has great advantages in the aspect of environmental protection; the method is simple to operate, free of complex treatment steps and suitable for industrial production, and when the boron compound is selected from sodium metaborate, sodium perborate or a mixture of borax and sodium metaborate, the yield and purity of the process are higher, and sulfoxide impurities are fewer.

The invention provides a lead storage battery positive electrode lead paste and a preparation method thereof. The invention provides a rare earth-carbon-based composite lead storage battery positive electrode additive formula which comprises the following components in parts by weight: 25-35 parts of a carbon material, the carbon material comprises a carbon nanotube, graphene and expanded graphite, and the mass ratio of the carbon nanotube to the graphene to the expanded graphite is 1: 2: 3; 20 to 30 parts of a binder; the rare earth comprises a Ce element, and the molar ratio of the Ce element to the Sn element is 1: (8-10); 30 to 40 parts of a 4BS seed crystal; 50 to 80 parts of nano red lead powder; 1 to 1.5 parts of polyester fiber; and 5-10 parts of sodium perborate. According to the invention, a multi-dimensional conductive network is constructed through the combination of the carbon nanotubes, the graphene, the expanded graphite and the conductive binder, a stable three-dimensional network is formed, the problem of conductive anisotropy of traditional lead paste is solved, heterojunctions are formed through the SnO2-rare earth mixture, oxygen evolution overpotential is reduced, grains are refined, and corrosion of a positive grid is inhibited.

The application belongs to the field of detection reagents, and particularly relates to a single-component luminol chemiluminescence substrate liquid and a preparation method thereof. The single-component luminol chemiluminescence substrate liquid comprises the following components: sodium acetate, sodium perborate, N-N dimethylacetamide, beta-cyclodextrin, luminol, 4-morpholinopyridine, p-acetylaminophenol, 4-hydroxyphenylacetic acid, phenothiazine-10-yl-propyl sulfonic acid sodium salt and isothiazolinone. The purpose of the application is to solve the technical defects that the luminol chemiluminescence substrate liquid in the prior art must be packaged in two components due to the instability of the luminous agent and the oxidizing agent in the liquid phase, leading to inconvenient use and easy introduction of operation errors, so as to provide a single-component luminol chemiluminescence substrate liquid and a preparation method thereof, which have high storage stability, high luminous performance and convenient use.

A composition for the oxidative color change of keratinous fibers, comprising – based on its total weight – (a) one or more per compounds from the group consisting of sodium percarbonate, potassium percarbonate, sodium perborate and potassium perborate in a total amount of 0.5 to 14.0 wt.%, and (b) one or more persulfates from the group consisting of ammonium persulfate, potassium persulfate and sodium persulfate in a total amount of 5.0 to 60.0 wt.%, and (c) less than 10.0 wt.% water, characterized in that it contains 3.0 to 12.0 wt.% sodium percarbonate, and contains 7.0 to 16.0 wt.% ammonium persulfate, and contains 20.0 to 45.0 wt.% potassium persulfate, and contains 1.0 to 6.0 wt.% sodium persulfate.

The invention belongs to the technical field of refractory materials, and particularly relates to a preparation method of a special refractory crucible. During preparation, the alpha-silicon carbide powder, the metal silicon powder, the fluoride powder, the sodium perborate, the precursor and the kaolin are subjected to dry mixing, and deionized water is added for stirring; adding the sol and the coupling agent, continuously stirring, mixing to form wet slurry, drying, crushing to obtain coarse particles, and aging to obtain an aged material; performing isostatic pressing on the aged material, and demolding to obtain a crucible green body; and pre-sintering the crucible green body, and sintering at high temperature to obtain the fire-resistant special crucible. The large holes are filled with the formed flowing glass phase, and the closed micropores are formed under the wrapping of the glass phase through fluoride reaction, so that a permeation channel of high-temperature molten metal is fundamentally blocked, the eroded depth of the crucible during use is reduced, the technical defect that open pores are easily formed after alpha-silicon carbide powder is sintered is overcome, and the service life of the crucible is prolonged. And the compact fire-resistant special crucible is prepared.

The application discloses a method for efficiently degrading bisphenol compounds by using UV-LED combined with sodium perborate, and relates to the technical field of water treatment. The method adds sodium perborate into a bisphenol compound solution to be treated, and irradiates the water body by using UV-LED, so that the bisphenol compounds can be efficiently removed. The application utilizes the activated sodium perborate to efficiently degrade bisphenol compounds, and has the advantages of simple operation, low cost, excellent performance and high application value.

The application belongs to the technical field of chemical industry and relates to a preparation method of a novel chiral bipyridine and application of the chiral bipyridine in catalytic reaction. Various benzyl bromides with 4,5-diazofluorene as a skeleton are reacted to generate a series of chiral bipyridine ligands, then under the participation of the ligands, indolines and quinoline nitrogen-containing heterocyclic compounds are reacted with pinacol diboronic acid under the catalysis of [IrOMe(COD)2] as a metal catalyst, and then a series of phenol compounds are obtained through oxidation of sodium perborate. The novel chiral bipyridine ligand developed by the method has the advantages of good site selectivity and excellent reaction yield without using strong acid and strong base in the process of C-H bond selective boronation.

A method for sterilizing and decontaminating post-consumer absorbent products polluted with organic compounds derived from human metabolism including drug residues, the post-consumer absorbent sanitary products comprising fractions of plastic, super-absorbent polymers (SAP), and optionally cellulose, the method including at least the steps of: sterilizing (SR) the absorbent sanitary post-consumer products by heating to a temperature equal to or less than 140° C., and to a pressure lower than 4 bar, decontaminating (DC) the post-consumer absorbent sanitary products of organic compounds by treating with an oxidizing composition comprising at least one compound selected from the group consisting of hydrogen peroxide, sodium percarbonate, potassium percarbonate, sodium perborate, potassium perborate, potassium monopersulfate, ammonium persulfate, sodium persulfate, potassium persulfate, and ozone. The at least one compound is contained in the oxidizing composition in an amount equal to or greater than 2% by weight with respect to the dry weight of the post-consumer absorbent sanitary products.

The invention belongs to the field of organic synthesis, and particularly relates to a minoxidil synthesis method, which comprises the following steps: by taking 2, 4-diamino-6-chloropyrimidine as a starting material, oxidizing the starting material by sodium perborate tetrahydrate, and carrying out synergistic catalysis by adopting piperidine and ionic liquid. According to the invention, sodium perborate tetrahydrate and EDTA are adopted to inhibit the occurrence of peroxidation by-products; the ionic liquid is adopted, decomposition of oxides caused by high temperature is avoided, and the ionic liquid effectively inhibits side reactions; the dosage ratio of piperidine to 2, 4-diamino-6-chloropyrimidine-3-oxide is reduced, so that complete reaction is ensured, and side reaction caused by excessive piperidine is avoided; according to the method, the safety of the oxidation process is high, side reactions are effectively avoided, post-treatment is simple, and the method is green and environmentally friendly.

The invention discloses a novel synthesis method of dutasteride, which is characterized in that sodium perborate is used as an oxidizing agent, and a proper solvent system and pH value are designed, so that efficient oxidation of hydrogenated dutasteride carboxylic acid iodide is realized, toxic reagents are prevented from being used, and impurities can be reduced; the high-purity dutasteride can be obtained through simple refining, the operability is high, and the method is suitable for industrial mass production.

This invention discloses a method for preparing potassium perborate from sodium perborate mother liquor using modified potassium-form resin, belonging to the field of resource comprehensive utilization technology. The method includes: pretreating a 732 type strong acid cation exchange resin to convert it to the potassium form, then modifying it with a 15-crown ether-5 ethanol solution to obtain a crown ether-modified potassium-form resin; passing the sodium perborate mother liquor through an exchange column packed with this resin, and performing ion exchange at 20-30℃, utilizing the specific selectivity of the crown ether for sodium ions to efficiently replace Na ions in the mother liquor with K ions in the resin, obtaining a pure potassium perborate solution; cooling the solution at -5~5℃ for crystallization, separation, and drying to obtain a high-purity potassium perborate product. This invention directly utilizes waste mother liquor as raw material, with a mild process, and produces a product with high active oxygen content (>16%), uniform particles, and good stability. It solves the problems of high cost, heavy pollution, and poor product quality associated with traditional processes, achieving green and high-value utilization of waste resources.

The invention relates to the technical field of etching solutions, and discloses a multilayer copper-molybdenum etching solution for the LED field, which comprises the following components by mass percent: 5.5-7.5% of sodium perborate; 6%-8% of hydrogen peroxide; 6%-7% of triammonium phosphate; 1%-2% of citric acid; 1%-2% of sodium citrate; 1.0% to 1.5% of iminodiacetic acid; 0.05%-0.1% of tin sulfate; 0.30%-0.45% of a dipotassium hydroxyethylidene-1, 1-diphosphonate solution; 0.08%-0.10% of sodium nitrite; 0.2% to 0.4% of water-soluble mercaptobenzothiazole; 0.02% to 0.05% of ethoxylated acetylene glycol; 0.02% to 0.05% of diethylene triamine pentamethylene phosphonate; and the balance of ultrapure water. A combination of sodium perborate and hydrogen peroxide is adopted as an oxidation system, a composite additive, a novel metal complexing agent and a surfactant matched with the etching solution are adopted, and the multilayer copper-molybdenum etching solution which is moderate in etching rate, good in anisotropy, high in substrate material selectivity and good in chemical stability is prepared.

This invention discloses a modified hard carbon anode material, its preparation method, and its application, belonging to the field of electrode material technology. The preparation method provided by this invention includes the following steps: pre-treating barbecue charcoal material, immersing it in a sodium perborate solution, washing and drying it, then performing an oxidation treatment, followed by carbonization under inert gas, and finally cooling to obtain the final product. The hard carbon anode material prepared by this invention is beneficial for increasing the C=O content in the material, improving the sodium storage specific capacity, and optimizing its rate performance and cycle performance. It is an ideal anode material for sodium-ion batteries. The sodium-ion battery assembled in this application exhibits high initial discharge specific capacity and high initial coulombic efficiency, excellent rate performance, and good stability.

The invention relates to the technical field of equipment cleaning agents, and particularly discloses a ferrous sulfide cleaning passivator. The ferrous sulfide cleaning passivator comprises, by weight, 0.5-2 parts of an oxidizing agent, 0.3-1 part of a chelating agent, 0.5-5 parts of a stabilizer, 0.2-1 part of a pH regulator and 90-100 parts of water. The oxidizing agent is one or more of sodium perborate, peracetic acid, potassium peroxymonosulfonate, butanedione and nitrobenzoic acid; the chelating agent is selected from one or more of ethylene diamine tetraacetic acid disodium salt, 1-hydroxyethylidene-1, 1-diphosphonic acid, amino trimethylene phosphonic acid, diethylene triamine penta (methylene phosphonic acid), glutamic acid tetrasodium diacetate and methylglycine trisodium diacetate. The ferrous sulfide cleaning and passivating agent provided by the invention has efficient cleaning and passivating effects, is environment-friendly and has a good application prospect.

The invention relates to the technical field of cleaning of environmental protection equipment, in particular to a cleaning method of a reverse osmosis membrane. The cleaning method comprises the following steps: carrying out bubbling treatment on reverse osmosis membrane produced water to obtain a backflushing medium; carrying out first cleaning on the reverse osmosis membrane by using a backwashing medium to obtain a first cleaned membrane; the primary cleaning film is soaked with a cleaning agent, and a second cleaning film is obtained; wherein the cleaning agent is prepared from the following raw materials: citric acid, polyaspartic acid, sodium perborate, cellulase and tannic acid; performing second cleaning on the second cleaning film at preset pressure to obtain a third cleaning film; and performing third cleaning on the third cleaning membrane to obtain the regenerated reverse osmosis membrane. According to the cleaning method, the membrane flux recovery rate and the salt barrier rate recovery rate are synchronously improved from two core dimensions of pollutant removal thoroughness and membrane structure protection integrity through the progressive design of physical pre-cleaning, chemical targeted cleaning and multi-stage deep purification and in combination with the synergistic effect of all components of the cleaning agent.

The present application relates to the technical field of organic synthesis, and in particular to a method for preparing amido phenethyl alcohol compounds by structural reorganization of indole compounds. The method for preparing amido phenethyl alcohol compounds by structural reorganization of indole compounds provided by the present application uses borane compounds as a reducing agent, reduces indole compounds to generate benzazaborinine, and then further opens the ring and oxidizes to generate amido phenethyl alcohol compounds by sodium borate tetrahydrate. The structural reorganization of indole compounds successfully realizes the efficient synthesis of a series of amido phenethyl alcohol compounds, and the reaction process has few by-products, high selectivity and high yield of amido phenethyl alcohol compounds, and simple subsequent separation and purification. Moreover, the method provided by the present application is simple in process, green and environmentally friendly, simple in operation, low in cost, high in safety, and suitable for industrial production.

The invention belongs to the field of detection reagents, and particularly relates to a single-component luminol chemiluminescent substrate solution and a preparation method thereof. The single-component luminol chemiluminescent substrate solution is prepared from the following components: sodium acetate, sodium perborate, N, N-dimethylacetamide, beta-cyclodextrin, luminol, 4-morpholinopyridine, acetamidophenol, 4-hydroxyphenylacetic acid, phenothiazine-10-yl-propyl sodium sulfonate and isothiazolinone. The invention aims to solve the technical defects that in the prior art, a luminol chemiluminescent substrate solution must be packaged by two components due to instability of a luminescence agent and an oxidizing agent in a liquid phase, so that the luminol chemiluminescent substrate solution is inconvenient to use, and operation errors are easy to introduce. Therefore, the invention provides the single-component luminol chemiluminescent substrate solution with high storage stability, high luminescent property and convenience in use and the preparation method thereof.

The invention discloses a method for efficiently degrading common dyes in wastewater by using UV222 in combination with sodium perborate, and relates to the technical field of water treatment. UV222 (wavelength of 222nm) released by a plasma generator is combined with sodium perborate to form a synergistic oxidation system, high-activity free radicals are generated through photochemical activation, and efficient degradation of common dye pollutants in a water body is realized. A UV222 light source with a specific wavelength is adopted, so that the activation efficiency and the free radical yield of sodium perborate can be remarkably improved. Experiments show that the 30 min degradation rate of the method to methylene blue (MB) can reach 95% or above, and the method is suitable for various common dyes such as rhodamine B, malachite green, methyl orange and methyl violet. Compared with a conventional dye treatment technology, the method has the advantages of being higher in efficiency, lower in cost, simpler and more convenient to operate and remarkable in application value.

A washing machine drum cleaner, a preparation method therefor, and a use thereof. The washing machine drum cleaner comprises the following components by mass percentage: peroxide, 30%-50%; inorganic base, 3%-10%; buffering base, 15%-20%; sodium lauryl sulfate, 1%-5%; protease, 1%-5%; and the remainder being anhydrous sodium sulfate. The inorganic base is potassium hydroxide and / or sodium hydroxide, the buffering base is sodium carbonate and / or sodium bicarbonate, and the peroxide is sodium percarbonate and / or sodium perborate.

The invention belongs to the technical field of organic synthesis, and discloses a preparation method and application of a metal-free 1-hydroxycarbazole derivative. The preparation method of the 1-hydroxycarbazole derivative comprises the following steps: (1) mixing a compound I and an organic solvent I, adding sodium hydride under an ice bath condition, heating and mixing, then adding R1COCl, and mixing to obtain a mixture a; (2) removing the organic solvent I in the mixture a, adding an organic solvent II and a dichloromethane solution of boron tribromide into the mixture a in a protective gas atmosphere, and reacting to obtain a mixture b; and (3) removing the organic solvent II in the mixture b, adding sodium perborate tetrahydrate and a potassium carbonate solution into the mixture b, mixing, extracting, drying and concentrating to obtain the 1-hydroxy carbazole derivative. The structural formula of the compound I is shown in the specification; the preparation method is free of transition metal catalysis and low in cost, and the yield of the obtained 1-hydroxycarbazole derivative is high.

The invention relates to the technical field of deodorants, and particularly discloses an efficient deodorant as well as a preparation method and application thereof. The invention discloses an efficient deodorant which is specifically prepared from the following components in percentage by weight: 0.6 to 11 percent of organic acid, 0.1 to 1 percent of sodium citrate, 1.1 to 6 percent of oxidant and 0.1 to 1 percent of undecylimidazoline. And the balance of water. The organic acid is formed by mixing tannic acid and citric acid according to the weight ratio of (0.1-1): (0.5-10); the oxidizing agent is formed by mixing sodium percarbonate and sodium perborate according to the weight ratio of (1-5): (0.1-1). The efficient deodorant provided by the invention has a remarkable deodorization effect and can efficiently remove malodorous gas; and the deodorant has low corrosion to carbon steel and stainless steel equipment, and the equipment corrosion risk is reduced.

This application belongs to the technical field of passivation and deodorization agents, specifically providing a gas-phase ferrous sulfide deodorizing and passivating agent and its preparation method. A gas-phase ferrous sulfide deodorizing and passivating agent includes component A and component B; component A includes the following components: a multifunctional block copolymer, a penetrant, a corrosion inhibitor, an antioxidant, isopropanol, and deionized water; component B includes the following components: triethanolamine, sodium perborate, and deionized water; the multifunctional block copolymer is prepared by reacting polyethylene glycol monomethyl ether, octadecyl acrylamide, and dopamine methyl acrylamide. The gas-phase ferrous sulfide deodorizing and passivating agent prepared by this application has good deodorizing, passivating, and cleaning effects.

Disclosed is a chemical composition for electronically activated chemical rock breaking system, and it includes potassium chlorate with ratio of 20-55% by weight of the chemical composition, sodium perborate and / or Tetra acetyl ethylene diamine (TAED) or any combination of them with ratio of 10-24% by weight of the chemical composition, at least one fruit and / or vegetable powder selected from the group consisting of carob powder, dried grape powder, dried currant powder, dried date powder, dried coconut fruit powder, dried pumpkin powder, dried sugarcane, sugar beet powder, dried tamarind powder and dried fig powder with ratio of 9-28% by weight of the chemical composition, at least one powder selected from the group consisting of olive pulp powder, nut shell powder, coconut shell powder, pumpkin seed shell powder, sunflower seed shell powder with ratio of 5-20% by weight of the chemical composition.

The invention relates to the technical field of chemical cleaning of industrial equipment, in particular to a deodorizing and passivating double-effect cleaning agent as well as a preparation method and application thereof. The cleaning agent specifically comprises the following components in percentage by weight: 0.2-1.5% of sodium carbonate; 0.1 to 1% of EDTA-2Na (Ethylene Diamine Tetraacetic 2 to 6% of PMPS; 0.5-2% of sodium perborate; 0.1-1% of tannic acid; 0.08 to 0.2 percent of calcium lignosulphonate; 0.1 to 0.3 percent of succinic acid dihydrazide; and the balance of water. The deodorizing and passivating double-effect cleaning agent does not contain heavy metal with the atomic weight larger than 40, the chemical oxygen demand is not larger than 2000 mg / L, good deodorizing and passivating effects are achieved, sulfur-containing substances in industrial equipment can be effectively removed, meanwhile, a good passivating effect on ferrous sulfide is achieved, and the problems of peculiar smell and spontaneous combustion during equipment maintenance are solved.

This invention provides a long-acting oxygenating agent for aquaculture water, its preparation method, and its application, belonging to the field of aquaculture technology. It comprises the following weight components: 5-20 parts sodium percarbonate, 65-85 parts sodium perborate, 5-15 parts sodium tetraborate pentahydrate, 0.5-2 parts polyethylene glycol, and 0.2-0.5 parts magnesium stearate. After the oxygenating agent is added to the water, sodium percarbonate rapidly dissolves and releases oxygen, achieving a rapid oxygenation effect. Sodium tetraborate pentahydrate has a higher solubility than sodium perborate, rapidly dissolving and hydrolyzing in water to form a certain concentration of boric acid. This inhibits the dissolution and hydrolysis process of sodium perborate to some extent, slowing down the oxygen release rate and significantly increasing the oxygenation time and effectiveness of the oxygenating agent. The oxygenation time is extended to 16-36 hours, eliminating the need for workers to add oxygenating agent again at night, reducing aquaculture costs, improving the stability and sustainability of the aquaculture system, and increasing the economic benefits of aquaculture.

The invention relates to the technical field of ultrafiltration membrane cleaning, in particular to a composite cleaning agent and a preparation method and application thereof. The composite cleaning agent is prepared from the following raw materials in parts by mass: 6 to 10 parts of citric acid, 3 to 5 parts of polyaspartic acid, 4 to 6 parts of sodium perborate, 5 to 8 parts of cellulase, 8 to 12 parts of tannic acid and 500 parts of hydrophilic solvent. The composite cleaning agent realizes double breakthrough of ultrafiltration membrane flux recovery and cleaning waste liquid COD (Chemical Oxygen Demand) reduction through full-process control of chelating dispersion, oxidase hydrolysis and passivation protection. The membrane flux recovery rate of the ultrafiltration membrane is 93% or above, no biological membrane or inorganic scale or other residues exist on the surface of the ultrafiltration membrane, the chemical oxygen demand of the final cleaning waste liquid is low, the pH value of the cleaning waste liquid is moderate, and the cleaning waste liquid can be directly discharged.

The application belongs to the technical field of passivation deodorant, and specifically provides a gaseous ferrous sulfide deodorizing passivation agent and a preparation method thereof. The gaseous ferrous sulfide deodorizing passivation agent comprises component A and component B; the component A comprises the following components: a multifunctional block copolymer, a penetrating agent, a corrosion inhibitor, an antioxidant, isopropyl alcohol and deionized water; the component B comprises the following components: triethanolamine, sodium perborate and deionized water; and the multifunctional block copolymer is prepared by reaction of polyethylene glycol monomethyl ether, octadecyl acrylamide and dopamine methyl acrylamide. The gaseous ferrous sulfide deodorizing passivation agent prepared by the application has good deodorizing, passivating and cleaning effects.

The invention belongs to the field of disinfectants, and discloses a preparation method of a solution with antibacterial and peculiar smell removing functions, and a product and application thereof. The antibacterial and odor-removing solution is prepared from the following components in parts by weight: 1 to 15 parts of plant extracting solution, 0.5 to 5 parts of quaternary phosphonium salt, 1 to 4 parts of sodium cocoate, 0.9 to 1 part of sodium perborate, 0.1 to 0.3 part of zinc phenolsulfonate and the balance of ionized water. The preparation material source is convenient, the operation method is simple, the preparation condition is mild, the method is suitable for large-scale production, and the prepared liquid is safe and non-toxic, is suitable for various occasions, and has good popularization value in the application aspects of pet maintenance and air purification.

The application relates to the technical field of organic synthesis, in particular to a method for preparing N-phenylphenylenediamine compounds by structure reorganization of imidazole compounds. The method for preparing N-phenylphenylenediamine compounds by structure reorganization of imidazole compounds provided by the application uses a borane compound as a reducing agent, reduces the imidazole compound to generate a boron-nitrogen heterocyclic compound, and then further ring-opening and oxidizing the boron-nitrogen heterocyclic compound by sodium borate tetrahydrate to generate the N-phenylphenylenediamine compound; the reaction process has few by-products, the selectivity of the N-phenylphenylenediamine compound is high, the yield is high, and subsequent separation and purification is simple. Moreover, the method provided by the application is simple in process, green and environment-friendly, simple in operation, low in cost, high in safety, and suitable for industrialized production.