Showing papers on "Jet mill published in 1997"

Process for producing ITO sintered body

Abstract: An indium oxide-tin oxide (ITO) sintered body is prepared by mixing a tin oxide powder with an indium oxide powder, molding the resulting mixed powder to obtain a green body, and sintering the resulting green body. At least the tin oxide powder has beforehand been pulverized by colliding tin oxide particles with each other or against a collision substance in gas streams. At least 90 wt % of the pulverized tin oxide powder is preferably particles having a particle size of 0.2-10 μm. A jet mill can be used for the pulverization. The ITO sintered body has a density as high as 7.08 g/cm3 or more and, during sputtering, is free from nodule formation and is inhibited from generating particles.

Measuring and regulating solid charge for jet mill or impact pulverizer

Abstract: The method involves measuring continuously the instantaneous rpm of the impeller grader or the rotor of the impact pulverizer connected with the jet mill in the form of an rpm signal fluctuating over time. The strength of the rpm fluctuations is evaluated as a measurement value for the required feeding with solid matter. The measurement value or an electric signal derived from this is used to regulate the feed of solid material.

Rare-earth-iron-nitrogen based magnetic material and method of manufacturing the same

Abstract: A rare earth-iron-nitrogen based magnetic material has superior magnetic properties. A method of manufacturing the rare earth-iron-nitrogen based magnetic material controls the decline in the magnetic properties of the material during pulverizing processes, and pulverizes the material to a critical particle dimension for single-domain behavior. The fragility of the material is increased since the material includes at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W at 0.05-5% atomic percentage. The material is pulverized by a gas current type jet mill. Sample powder injected from a hopper is introduced from a supply mouth to a pulverizing chamber by nitrogen gas spouting from a pressure nozzle, and the powder is then accelerated to acoustic velocity by high pressure nitrogen gas spouting from gliding nozzles. As a result, the powder particles collide with each other. Pulverization is mainly carried out by collisions between powder particles, but can be accomplished by the collision of powder particles against the inner wall of a pulverizing chamber. The powder is then exhausted from a classifying zone.

Process for sampling in particle-laden gas streams

Abstract: In the process for the continuous collection of pulverulent or dusty samples from a particle-laden stream, a sample stream is drawn off from a particle-laden main stream in a pneumatic conveying line 17 and passed via a collection line 9 to a particle size measurement device 10. In order to reduce spin, the main stream in the conveying line 17 is passed through a venturi-like cross-sectional constriction 3, 4, 5, the cross-sectional area of which is 10 to 60% of the free cross-sectional area of the conveying line 17. Samples are then collected downstream from the cross-sectional constriction through one or more probe tubes 7, wherein a partial stream is collected from the main stream parallel to the direction of flow thereof. In conjunction with a jet mill 14, into which the product to be ground and the propellant air are continuously introduced, the particle size distribution measured in the continuously collected sample stream may be used as a control parameter in order to adjust a parameter which determines particle size distribution of the jet mill 14 in such a manner that the particle size distribution in the product stream remains constant.

Fluidised bed collision jet mill

Abstract: The mill has two feed lines (4,5) through which the milling air reaches the nozzle units (2,3) as two separate portions which are adjustable and controllable independently of each other and at pressures adjustable and controllable independently of each other. The bottom nozzle unit (2) comprises one or more, and preferably 2-5 jets which may be different from each other.

Fluidizing bed type jet mill

Abstract: The utility model discloses a fluidizing bed type airflow mill, which comprises a material bucket, a feeder, a disintegrating chamber, a transition chamber, a grading room, a collecting device and a star valve. The utility model is characterized in that the material bucket is additionally provided with an automatic sieving device, and the bottom of the disintegrating chamber is additionally provided with a set of material discharging device. The transition chamber between the disintegrating chamber and a grading chamber is additionally provided with a coarse and fine powder diverging device, and the star valve is additionally provided with an automatic shaking device. The fluidizing bed type airflow mill is different from any existing fluidizing bed type airflow mill so far, and the utility model is suitable for various super disintegrating fine powder.

Rare earth-iron-nitrogen magnetic material manufacturing method

Abstract: PROBLEM TO BE SOLVED: To provide a rare earth-iron-nitrogen type magnetic material having a high magnetic characteristics, manufactured by adjusting the prim. grain size (mean grain diameter) of the material in a range for 10-100μm and then pulverizing the material into fine grains of 0.1-3μm mean grain size which is generally formulated as RaFe(100-a-b-c) Mb Nc (R is at least one of rare earth elements, incl. Y, M is at least one of To, Zr, Hf, V, Nb, Ta, Cr, Mo, W, 5<=a<=20, 0<=b<=5, 3<=c<=30 in atom.% and the rest is Fe). SOLUTION: Prim. grains are mechanically pulverized and more pref. pulverized with hydrogen occlusion into grains of 100-100μm, pref. 10-45μm and then finely pulverized into particles, using a jet mill, pref. gas-flow type jet mill, this reducing the defects such as machining strains introduced into the sample power at fine pulverizing. Thus it is possibly to provide a rare earth-iron- nitrogen magnetic material having a high magnetic characteristics.

Resin coating film

Abstract: PROBLEM TO BE SOLVED: To form a resin coating film having a good smooth and sweat-free skin touch and a characteristic hand touch on the surface of a product, etc, from a resin containing the mixture of a solvent with fine gelatin powder having a specific particle size SOLUTION: Gelatin powder or gelatin granules are ground with a jet mill blowing out jet air cooled at -15 degC at a rate of 6-8kg/cm to obtain the gelatin powder having a finer particle size than 6μm without deteriorating the hydrophilicity of the gelatin The gelatin powder is homogeneously suspended in a solvent such as dimethylformamide or toluene The gelatin to be charged in the jet mill is preferably preliminarily classified with a sieve or an air- classifying machine to obtain the gelatin powder containing the gelatin powder having diameters of =90wt%

Counter-jet mill

Abstract: Counter-jet mill for particulate charging material, having a device 4 for feeding the charging material into a carrier gas flow 8, a downstream distributor 11 for dividing up the carrier gas flow into two partial flows 12, 13, and having two nozzles 14, 15, each of which is fed a partial flow 12, 13 and which are directed towards each other in a grinding chamber 16, the through-flow cross section of the nozzles being adjustable during operation and there being provided a measuring device 48 for measuring the pressure of the carrier gas flow 8 fed to the nozzles, the measured-value output of which device is fed to a control device 49, which controls the device 4 for feeding in the charging material in dependence on the measurement of the pressure.