Jet mill

About: Jet mill is a research topic. Over the lifetime, 803 publications have been published within this topic receiving 5686 citations.

Jet mill and jet pulverizing method

Abstract: PROBLEM TO BE SOLVED: To attain suppression of contamination and improvement of treatment efficiency, to omit or abbreviate classification treatment after pulverizing treatment by lessening particle size dispersion, to suppress wear of mechanical equipment and to attain fine pulverization while generating little heat and giving little influence to quality. SOLUTION: In a jet mill, a material to be pulverized introduced in a crushing chamber 12 of a horizontal disk shape is finely pulverized by a high-speed whirling stream produced by gas jetting from two or more jetting nozzles 20, 21 disposed in a circle shape along a side wall of the crushing chamber. Each jetting nozzle 20, 21 is installed in a state of penetrating a housing forming the crushing chamber and further a top end face 211 of each jetting nozzle 20, 21 is made to be a curved surface shape forming the same circumference surface as an inner wall surface of the crushing chamber. Thereby high-speed whirling stream of a concentric circle shape is stably produced and pulverization of particles of the material to be pulverized is carried out depending on collision between particles. COPYRIGHT: (C)2008,JPO&INPIT

Fluidized bed jet mill and process for comminuting of silicon

Abstract: The device for producing silicon seed particles, with a size of 50-1000 mu m, has vertically arranged jet chamber (8) with cylindrical cross-section, jet nozzle (4) arranged at the chamber, two zigzag counter flow-gravity separators (6) directly arranged at the jet chamber, and an inlet (6) for the silicon granulates. A grinding gas flow (1) is supplied into the jet chamber (8) via the jet nozzle. The jet chamber has a length of 2-8 sufficient for an expansion of grinding gas flow on the cross section of the jet chamber. The device for producing silicon seed particles with a size of 50-1000 mu m, has vertically arranged jet chamber (8) with cylindrical cross-section, jet nozzle (4) arranged at the chamber, two zigzag counter flow-gravity separators (6) directly arranged at the jet chamber, and an inlet (6) for the silicon granulates. A grinding gas flow (1) is supplied into the jet chamber (8) via the jet nozzle. The jet chamber has a length of 2-8 sufficient for an expansion of grinding gas flow on the cross section of the jet chamber, which has a flow cross-section of 20-30% smaller than the rectangular flow cross-section of the separator. One of the separators has larger rectangular flow cross-section than the other separator. The inlet of the silicon granulates with size of 300-5000 mu m takes place into the separator. A weighing unit is used to determine the weight of silicon particles in the jet chamber and the separator. The weight of silicon particles is regulated via a regulation unit for the dosage of the silicon granulates to obtain an optimal efficiency of the grinding process. An additional gas inlet for visible gas, is present in the inlet area of separator. Parts from an inner metallic covering with a coated inner wall, are contacted with the silicon particles. An inliner is installed into the parts provided with the coating, made of polycrystalline or monocrystalline silicon or quartz. The coating on the inner wall is made of silicon in mono- or polycrystalline form. An independent claim is included for a procedure for milling of silicon granulates to silicon seed particles by using the above device.

Dry purifying method of waste gas

Abstract: PURPOSE:To allow an absorbent to absorb an acidic noxious substance contained in waste gas within a short treating time, by a method wherein the absorbent comprising fine particulate quick lime or slaked lime with a particle size of 10mum or less is dispersed in the waste gas containing the acidic substance and the treated gas is subsequently subjected to dust collecting treatment. CONSTITUTION:Powdery quick lime or slaked lime is mutually impinged in a grinder 1 by a jet stream of high pressure air or overheated steam to be finely pulverized. The obtained fine particulate absorbent is introduced into waste gas along with high pressure air or overheated steam in a dispersing machine 2 to be uniformly dispersed throughout the waste gas. The dispersed fine particulate absorbent absorbs the acidic noxious substance in the exhaust gas. As a dust collecting apparatus 3, a bag filter is pref. used. The particle size of the absorbent is pref as small as possible but, with due regard to the operation cost of a jet mill, the absorbent having a particle size of 5mum or less and sharp particle size distribution curve is especially pref.

Method of manufacturing cellulose powder

Abstract: PROBLEM TO BE SOLVED: To provide a method of manufacturing cellulose powder narrow in a particle size distribution and relatively uniform in a particle size, after fibrillating a cellulose fiber.SOLUTION: The cellulose fiber is fibrillated to make a non-passing ratio of 100-mesh get more than 20 mass% and to make a non-passing ratio of 10-mesh get to 20 mass% or less, and is dry-ground thereafter by a jet mill.

Process for the production of high-strength isotropic graphite and of piston components for Otto engines which are made of high-strength isotropic graphite

Abstract: Process for producing a high-strength isotropic graphite, comprising a kneading step for mixing an aggregate comprising fine, carbon-containing powder and a pitch binder, a shaping step for shaping the raw material which has been prepared by repulverising the kneaded mixture using the rubber pressing method and a carbonisation and graphitisation step for firing to carbonise and graphitise the shaped product. The aggregate uses a fine mosaic-like coke powder as aggregate, whose mosaic-like coke powder is very finely milled in a jet mill to an average particle size of 1 mu m or less and a maximum particle size of 5 mu m or less and has an average electrostatic field strength at the surface of 1.2 x 10 esE/cm or more. The invention provides a high-strength isotropic graphite which has a high flexural strength of 120 MPa or more and is suitable for piston components for Otto engines (spark ignition engines), and provides a process for producing high-strength isotropic graphite.