Showing papers on "Jet mill published in 1993"

Microparticulation by Jet Mill Grinding of Protein Powders and Effects on Hydrophobicity

Abstract: A method was studied for microparticulation of protein for use as fat substitutes by superfine grinding. A jet mill produced particles <3 μm from egg white, casein and soybean hull. Microparticulation by grinding of egg white was easier than with casein or soybean hull. Hydrophobicity of casein increased by grinding to super fine particles but little or no effect was observed on soybean hull and egg white.

Method of milling

Abstract: An improved method of milling a particulate material in a jet mill is described. The material is fed from a holding vessel (1) to be entrained by a gas, the holding vessel (1) having an ullage which is maintained at a pressure of at least 0.05 MPa but less than the pressure at which gas is introduced to the jet mill. The method is particularly usefully employed in an impact jet mill in which the entrained particles impinge upon a surface (12), are reflected into another jet (13) and passed into a cylindrical separation chamber (17). The method enables such an impact mill to be operated under more energy-efficient conditions.

Effect of Different Milling Methods on Distribution of Particle Size of Rice Flours

Abstract: Two different methods (Sieve shaker, Elzone particle size analyzer) were used to investigate rice flour particle size obtained by various milling method. Results of Elzone particle size analyzer were more effective than Sieve shaker in determining particle size, and the distribution of particle size of rice flours was affected by the type of the milling methods used. A rice flour, prepared in a Pin mill had a particle size range of mesh, and 30.38% of the sample was in the particle size range mesh. A rice flour, prepared in a Colloid mill had a particle size range of mesh and more of flour particles appeared in the range mesh than any other particle size. A rice flour, prepared in a Micro mill had a particle size range of mesh, and 41.62% of the sample was in the particle size range over 500 mesh. A rife flour, prepared in a Jet mill had a finer flour particle size was over the particle size range 500 mesh. The finer rice flour gave the highest L value and the lowest a value. The wet-milled flour particles were observed as a cluster of starch granules and the particles of rice flour (dry-milling) were observed as fragment of rice grains. Scanning Electron Photomicrographs revealed that visual differences in structure between milling methods, and similar results with Elzone particle size analyzer method in particle size.

제분방법이 쌀가루 및 제품의 특성에 미치는 영향

Abstract: Rice flour obtained by four different milling methods, Pin mill. Colloid mill, Micro mill, and Jet mill, were used to investigate physico-chemical properties and product. Crude fat, ash, and protein contents of rice flours between different milling methods were similar. Blue value, amylose content, and damaged starch which related to properties of rice flour were reduced in the order that of Jet mill, Micro mill, Colloid mill, and Pin mill. Water absorption index, water solubility index, and water retention capacity increased as damaged starch increased. Hardness of gel(15%) is the highest value for Pin mill. The finer granules (Jet mill) had lower gelatinization onset(To) and peak(Tp) than any other rice flours. Those result are simillar with amylogram properties. Enthalpy of gelatinization increased as damaged starch increased. Jet mill had the highest score (p

Method and device for fluidized bed jet mill grinding

Abstract: Method and device for fluidized jet mill grinding wherein a nozzle construction is provided in which the momentum of the jet issuing from the nozzle is varied between areas of high momentum and areas of low momentum immediately after leaving the nozzle. A drop in pressure from the periphery to the core area of the jet develops so that flow channels are formed at right angles to the flow direction of the jet. Particles of the material to be comminuted are thereby drawn into the center of the jet where they are accelerated to the impact velocity necessary for their comminution during the course of the jet travel.

Flat fine metal powder and its production

Abstract: PURPOSE:To produce a flat fine metal powder having ductility and with the average particle diameter and the over age thickness specified. CONSTITUTION:A metal powder having ductility is obtained by the atomization method, the powder is wet-crushed by an attritor to <=2mum thickness and flattened, and the flat powder is crushed by a jet mill to the fine particles having <=20mum average diameter. At this time, efficiency is increased by the combination of the crushing by the jet mill and a flash classifier. The flat fine metal powder obtained by this invention is angular, and the powder is effectively applied to the soft magnetic powder to be used in a magnetic shielding paint.

Production of high strength isotropic graphite material

Abstract: PURPOSE: To industrially produce a high strength isotropic graphite material having such superior material strength as ≥120MPa bending strength and suitable for use as the material of a piston member for a gasoline engine. CONSTITUTION: Carbonaceous fine powder as an aggregate component is kneaded with a pitch binder, powdery starting material prepd. by crushing the kneaded material again is subjected to rubber press compacting and the resulting compact is baked, carbonized and graphitized to produce an isotropic graphite material. In this producing process, mosaic coke pulverized to ≤1μm average particle diameter and ≤5μm max. particle diameter with a jet mill and having ≥1.2×10 4 esu/cm 2 surface average intensity in an electrostatic field is used as the aggregate component. COPYRIGHT: (C)1995,JPO

Grinding method and device by jet mill

Abstract: PURPOSE:To shorten initial stabilizing time and to increase stability by increasing number of revolution of a rotary classifier rotor more than that of the rotor in the stabilized state of grinding to strengthen centrifugal force. CONSTITUTION:Materials to be ground are supplied to a grinding chamber 6 by a dispersing blade 14 on the upper part of a rotor and the rotational force of the rotor and are ground by a jet air from a grinding nozzle 3 and a colliding member 2 to return the materials to a rotary classifier rotor. The ground solid materials are seperated into particles having a diameter not more than the object one of ground particles and particles having a diameter larger than that. The particles having a diameter not larger than the object one of ground particles pass through a discharging pipe 5 and are collected in an outside cyclone to be catched up and sent to the next process as a product. On the other hand, the particles having a diameter larger than the object one of ground particles are blown off to the circumferential part of the grinding chamber 6 again by the centrifugal force of the rotary classifier rotor to be ground again by the jet air and the colliding member 2. At this time the centrifugal force in the grinder is increased more than that in the start of grinding to forcibly supply the charging materials to be ground to the grinding zone.

Fluidized-bed jet milling of ceramics

Abstract: Many abrasive ceramic powders require milling and/or classification to achieve a required particle-size distribution. A solution for processing fine powder carbides, nitrides, borides, alumina, and other ceramics is a jet-mill.

Production of r-t-m-n-based alloy powder

Abstract: PURPOSE:To provide a permanent magnet powder easy to handle and having a high coercive force by coarsely crushing a superquench thin strip having a ThMn12-type crystal structure, further crushing the powder with a jet mill and then nitriding the product under specified conditions CONSTITUTION:A molten alloy consisting of 7-9atom% of R (at least one kind among rare-earth elements contg >=50% Pr or Nd), 76-87% of T (Fe or a part of Fe substituted by <=50% Co or Ni) and 35-17% of M (at least one kind among Ti, V, Cr and Mo) is superquenched by a rotary roll The obtained thin-strip alloy of a ThMn12 crystal structure having a texture of 001-10mum average crystal grain diameter is coarsely crushed by a jet mill in the supersonic flow of N2 gas to obtain the fine powder having 2-50mum average grain diameter The product is kept at 300-650 degC in 1-10atm N2 gas for 10min to 6hr and nitrided, and the alloy powder contg 7-9atom% R, 76-87% T, 35-17% M and 3-12% N is obtained

Fine precipitated silicic acid having large specific surface area and its production

Abstract: PURPOSE:To provide precipitated silicic acid having a large BET specific surface area of 600-800m /g and a small average secondary particle diameter of 0.1-5.0mum. CONSTITUTION:An aq. soln. of alkali metal silicate and sulfuric acid are simultaneously added and brought into a neutralization-precipitation reaction at 5-40 deg.C reaction temp. After the end of the reaction, the resulting liq. is acidified and filtered. The separated solid is washed, pulverized and dried in a jet mill with superheated steam or heated air to obtain the objective novel precipitated silicic acid having a large specific surface area and a small average secondary particle diameter.