63results about How to "Raise the potential gradient" patented technology

The invention relates to a high-performance Pr series ZnO voltage sensitive ceramic material and a preparation method thereof, and belongs to the technical field of preparation and application of electronic ceramics. Nano composite ZnO ceramic powder is prepared by wrapping the surface of nano ZnO by a liquid phase deposition method, so that the doped components are mixed uniformly, the micro structure of a product is uniform, the performance of the Pr series ZnO voltage sensitive ceramic material is improved and the sintering temperature of the ceramic material is effectively reduced and the energy consumption is reduced. The Pr series ZnO voltage sensitive ceramic material with high electric potential gradient, a large nonlinear coefficient, and small leakage current is prepared by optimizing the reasonable ratio of all doped components and combining a liquid phase wrapping process, and meets the requirements of high-voltage and supervoltage high-quality arresters and other devices; and the variety of the doped elements for preparing the high-voltage ZnO voltage sensitive ceramic is few, the source of the doped elements is abundant, and the method is simple, so that production cost is lowered.

This invention discloses a preparation technology of rare-earth oxide doped ZnO-Bi2O3 group pressure sensitive ceramic, prefireing components except Al(NO3)3 9H2O in 900deg C for 30min, and then mixing ball milling granulating with Al(NO3)3 9H2O and residual ZnO, pressing to shape green compact, heating from room temperature to 1180deg C by the rate of 100-200deg C/h and preserving heat for 4h after discharging rubber, lowing temperature to room temperature by the rate of 60-200deg C/h; Annealing sintered body by 600-800deg C for 2h, the getted rare-earth oxide doping ZnO-Bi2O3 group pressure sensitive ceramic sample after detemperature rate 0.1-2deg C/min, the homogeneity of electric property is improved obviously, moreover, extenuating center soft+-phenomenon in high extent, can be used to make lightning protection arrester products of super/extra-high voltage electric transmission system.

The invention provides a high-performance direct-current zinc oxide varistor and a preparation process thereof. The varistor is prepared from the following components in parts by mol: 90 to 98 parts of ZnO, 0.5 to 7 parts of Bi2O3, 0.1 to 10 parts of Sb2O3, 0.1 to 2 parts of Co2O3, 0.1 to 5 parts of SiO2, 0.1 to 5 parts of MnO2, 0.1 to 5 parts of Cr2O3, 0.1 to 4 parts of NiO, 0.1 to 1 part of B2O3, 0.01 to 0.6 part of Al(NO3) 3.9HO, 0.01 to 0.5 part of V2O5, 0.01 to 0.5 part of CeO2 and 0.05 to 0.5 part of silver glass powder. According to the varistor and the preparation method thereof, by adding B2O3, V2O5, CeO2 and silver glass powder in a traditional varistor, and by coating a varistor blank surface with bismuth-containing oxide during high-temperature firing and by carrying out direct-current coating and diffusion treatment on the varistor obtained by high-temperature firing according to the preparation process, various performances, such as aging resistance, rectangular wave current impact tolerance stability and large current impact tolerance stability of the varistor can be greatly improved, and the preparation process has the advantages of low cost, high efficiency and the like.

The invention relates to a rare earth oxide composite additive for a zinc oxide varistor and a preparation method thereof and belongs to the technical field of varistor material preparation. The preparation method comprises the following steps of: precipitating two or more rare earth element salts, filtering to obtain a precipitate, washing, drying, and calcining to obtain the rare earth oxide composite additive for the zinc oxide varistor. Components of the rare earth oxide composite additive prepared are uniformly mixed. Particle distribution range is narrow. Hydrogen chloride in mother liquor after precipitation can be recovered and reused. There is no discharge of harmful gases such as nitrogen oxide and the like during the calcining process, the whole process is environmentally friendly and has no pollution. In the meanwhile, in comparison with a plurality of rare earth oxide respectively added in a zinc oxide varistor, the rare earth oxide composite additive prepared by the preparation method can be used to make various rare earth elements added to be uniformly distributed, substantially improve the microstructure of the zinc oxide varistor and greatly raise its comprehensive electric properties.

The invention relates to a ZnO voltage-sensitive ceramic material and particularly relates to a preparation method of composite nano ZnO voltage-sensitive ceramic powder. The preparation method comprises the following steps: preparing soluble zinc salt, bismuth salt, cobalt salt and manganese salt which are used as raw materials, respectively preparing into aqueous liquor, mixing 95% (in mole percentage) of ZnO, 3% of Bi2O3, 1% of CoO and 1% of MnO, and uniformly stirring; slowly adding ammonia water into mixed liquor obtained in the step (1), regulating the pH to 8-8.5 to obtain mixed liquor, continuously stirring until mixing uniformly; carrying out suction filtration onto precipitates obtained in the step (2), sufficiently washing to remove impurities by using deionized water and alcohol, placing obtained precursor in water or alcohol medium for refluxing for 2-8 hours, and controlling a refluxing temperature to 70 DEG C-80 DEG C; finally, carrying out suction filtration on the powder obtained by refluxing, sufficiently washing to remove impurities by using deionized water and alcohol, finally drying in a vacuum drying box, and grinding to obtain nano composite ZnO powder.

The invention relates to the technical field of piezoresistor discs for lightning arresters, in particular to a zinc oxide resistor disc and a preparation method and application thereof. The zinc oxide resistor disc provided by the invention is prepared from the following raw materials in percentage by mole: 85-95% of ZnO, 0.01-4.0% of Bi2O3, 0.01-4.0% of Sb2O3, 0.05-3.0% of Co2O3, 0.01-2.0% of MnO2, 0.01-3.0% of NiO, 0.01-2.0% of Fe2O3, 0.01-2.0% of A12O3, and 0.01-2.0% of Dy2O3. According to the zinc oxide resistor disc provided by the invention, a toxic substance Cr2O3 does not need to be added, various components including ZnO, Bi2O3, Sb2O3, Co2O3, MnO2, NiO, Fe2O3, Al2O3 and Dy2O3 cooperate with each other, such that the zinc oxide resistor disc has the excellent performances of highpotential gradient, high square wave through-flow capacity, low residual voltage, high square wave current and large current impact resistance, good aging resistance and the like.

The invention provides a horizontally arranged cathode vacuum electroosmosis sludge dehydration device and method. The horizontally arranged cathode vacuum electroosmosis sludge dehydration device comprises a sludge pond, a filter pipe net is horizontally paved in the sludge pond, plane cathode is horizontally and closely paved on the upper part of the filter pipe net, the plane cathode and the filter pipe net are both buried into the sludge in the sludge pond, plane anode is arranged on the upper surface of the sludge in the sludge pond, the plane anode is electrically connected with the positive pole of a direct-current power supply, and the plane cathode is electrically connected with the negative pole of the direct-current power supply; and a water-gas separation device is arranged onthe edge of the sludge pond, one end of the water-gas separation device communicates with a vacuum pump, and the other end of the water-gas separation device communicates with the filter pipe net. According to the horizontally arranged cathode vacuum electroosmosis sludge dehydration device and method, the filter pipe net and the plane cathode are sequentially arranged at the bottom of the sludgepond from bottom to top, the plane anode is paved on the surface of the sludge, the gravity field and the electric field can be fully and effectively utilized, and thus water in the sludge is separated from the sludge under the joint action of the electric field and the gravity field.

Disclosed herein is an electrical insulating oil composition using a high-boiling-point aromatic fraction. The oil composition comprises a component having a distillation range of 280-330 DEG C, obtained by continuously distilling an aromatic hydrocarbon fraction from a platforming or aromatizing process. According to the disclosed invention, an electrical insulating oil composition having excellent voltage-withstand capability and excellent gas absorption capability can be obtained from an aromatic fraction. Also, the electrical insulating oil contains no unstable components, resulting in an increase in electrical properties, and thus has advantages of high stability and high potential gradient.

The invention discloses a production process of a zinc oxide resistance chip with high electric potential gradient and strong through-current capability. The zinc oxide resistance chip comprises the following raw materials: a main ingredient zinc oxide and a dopant, wherein the dopant comprises bismuth sesquioxide, cobalt sesquioxide, nickel sesquioxide, chromium sesquioxide, stibium sesquioxide, silica, yttrium sesquioxide and zirconia; the mass percent of zinc oxide is not less than 90%. The production process comprises the following steps: (1) ball-milling mixing; (2) drying granulation; (3) dry pressing; (4) sintering; and (5) silver electrode coating. By virtue of the production process, the zinc oxide resistance chip with high electric potential gradient and strong through-current capability can be prepared based on a solid-phase synthesis method.

The invention provides a zinc oxide varistor which comprises the following raw materials: 68-92 parts of zinc oxide, 2-18 parts of bismuth trioxide, 0.4-19 parts of cobaltosic oxide, 0.3-11 parts of cobalt sesquioxide, 3-24 parts of stannic oxide, 0.2-11 parts of manganese dioxide, 0.05-5.4 parts of oxyde de nickel, 3-16 parts of silicon dioxide, 0.2-6.9 parts of boron oxide, 0.003 to 0.06 part of aluminium nitrate, 0.006 to 0.07 part of glass dust, 0.02 to 0.4 part of rare earth, 0.02-0.4 part of praseodymium system oxide, 0.3-10 parts of chromium sesquioxide, 0.5-4 parts of boric acid and 0.8-3.5 parts of silver nitrate. The invention also provides a preparation method of the zinc oxide varistor. Compared with the prior art, the preparation method provided by the invention has the advantage that procedures of pulp drying, calcining inside a kiln and grinding for an auxiliary additive are omitted; the pulp of the auxiliary additive is directly mixed with zinc oxide to form a raw material under high-speed stirring, procedures are reduced, energy is saved, moreover, secondary pollution caused by the auxiliary additive can be avoided.

The invention relates to a nanotin dioxide piezoresistor composite powder material. The material is prepared from tin dioxide, bismuth trioxide, antimony trioxide and yttrium trioxide. The preparation method is characterized by preparing the high-performance nanotin dioxide composite powder by adopting a forced micromixing method and a colloid mill as a reaction container through a nucleating/growth isolation method. The preparation of the nanotin dioxide piezoresistor composite powder with excellent performance is a crucial to obtaining of a high-performance piezoresistor. The forced micromixing technology is adopted during nucleating/growth isolation preparation, a salt solution and an alkaline solution are fast and fully mixed at a gap between a rotor and a stator of the reactor, so that the material has the characteristics of being small in particle size and uniform in distribution; zinc element and other modification elements can be coprecipitated during the growth of crystal grains, so that the microscopic uniformity of the composite powder can be improved. Therefore, the nanotin dioxide piezoresistor composite powder which is small in grain size, uniform in the distribution of modification oxides, and narrow in the distribution of grain sizes can be obtained.

The invention provides a zinc oxide piezoresistor medium with high electric potential gradient and high nonlinear coefficient. The zinc oxide piezoresistor medium is prepared from the following components in parts by mol: 100 parts of ZnO, 0.03 to 1.5 parts of Sb2O3, 0.03 to 1.5 parts of Co2O3, 0.03 to 1.5 parts of Bi2O3, 0.03 to 1.5 parts of Ni2O3, 0.03 to 1.5 parts of Cr2O3, 0.03 to 1.5 parts of MnNb2O6, 0.03 to 0.8 part of Al2O3, 0.03 to 0.8 part of zinc borate, 0.03 to 0.8 part of LiNO3 and 0.03 to 0.8 part of MnSiO3. The invention further provides a preparation method of the zinc oxide piezoresistor medium with the high electric potential gradient and the high nonlinear coefficient. The zinc oxide piezoresistor medium provided by the invention has the advantages of high electric potential gradient, high nonlinear coefficient and strong pulse impact endurance capability.

The invention discloses a method of preparing a zinc oxide product by adding nano antimony oxide. The method comprises the following steps: weighing all components according to mass percentage: 3.5 to4.0 percent of bismuth oxide, 2.7 to 3.7 percent of nano antimony oxide, 1.0 to 1.8 percent of cobalt oxide, 0.6 to 1.3 percent of silicon oxide, 0.6 to 0.9 percent of manganese oxide, 0.8 to 1.4 percent of chromium oxide and other additives and the balance of zinc oxide; mixing all raw materials except the nano antimony oxide; then adding a dispersing agent, an adhesive solution and a defoamingagent, adding purified water to enable the solid content to be 60 to 65 percent and carrying out ball milling; then adding the nano antimony oxide, pulping, tabletting, discharging glue, carrying outhigh-temperature sintering and annealing, coating the annealed resistor disc with a side glass insulating layer and drying the insulating layer; rubbing down two end faces of the resistor disc and spraying aluminum electrodes on the two end faces of the resistor disc by using an arc spraying method, thus obtaining a zinc oxide arrester product. The zinc oxide arrester prepared by the method disclosed by the invention has high potential gradient and good energy absorption capability.