Showing papers on "Jet mill published in 1985"
TL;DR: Compressed air-powered jet mills used in the chemical and food industries for grinding and classifying powders were adapted as a powder generator for inhalation experiments and stability of aerosol concentration during six-hour continuous generation was 15 to 20%.
Abstract: Compressed air-powered jet mills are used in the chemical and food industries for grinding and classifying powders. We adapted one type of these fluid energy mills as a powder generator for inhalation experiments. The generating system included a jet mill and a screw feeder, the jet mill consisting of an elongated channel, a feeding jet to deliver the material into the channel, and two high-speed air jets. High speed air circulating in the channel created turbulence and centrifugal forces to disperse powder. The jet mill used can be operated from 25 to 100 psig at flow rates of 300 to 900 L/min. Two test materials–a solvent yellow dye and a dye mixture of solvent green and solvent yellow–were used. Both dyes were soft and sticky and could not be dispersed with several other powder generators tested at the concentrations required for toxicity studies. Aerosol concentrations ranging from 10 to 1500 mg/m3 at a flow rate of 400 L/min were obtained by adjusting the feed rate to the jet mill. Stability of aeros...
31 citations
Patent•
08 Feb 1985
TL;DR: In this article, a fine granular Ca-absorbant with a specific particle size or less was used to remove an acidic substance in exhaust gas at a high removal ratio by a dry process in the same degree as a wet process.
Abstract: PURPOSE:To remove an acidic substance in exhaust gas at a high removal ratio by a dry process in the same degree as a wet process, by dispersing a fine granular Ca-absorbant with a specific particle size or less throughout high temp. exhaust gas before performing dust collection. CONSTITUTION:A powder of CaCO3, CaO or Ca(OH)2 is finely pulveized while particles are mutually collided by the energy of a high pressure air stream or an overheated steam stream in a jet mill 1 and a finely pulverized absorbent is directly introduced into high temp. exhaust gas along with the fluid stream from a dispersing machine 2 to be uniformly dispersed throughout the exhaust gas. The absorbent reacted with acidic substances such as SOx, HCl or HF is collected along with soot by a bag filter 3 while the purified gas is exhausted.
6 citations
Patent•
31 Jan 1985
TL;DR: In this article, 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.
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.
4 citations
Patent•
02 Sep 1985
TL;DR: In this paper, a fluidized bed jet mill is described, where a column of little speed is used as a feeder for a classifier, driven independently from the impulse of the jet emerging from the bottom nozzle.
Abstract: The apparatus disclosed relates to a fluidized bed jet mill having a grinding chamber which is free of fixtures which is provided in its bottom region with a nozzle with a gas jet emerging vertically upward. The jet mill is configured such that when the grinding chamber is filled with the material to be reduced in size, material and gas emerge from the bed of material as a column of little speed. The column serves as a feeder for a classifier provided above the surface of the material bed and driven independently from the impulse of the jet emerging from the bottom nozzle. For improving the efficiency of energy utilization in grinding, a plurality of additional nozzles are provided. The additional nozzles discharge below the surface of the bed of material and into the grinding chamber. The orifices of the additional nozzles are uniformly distributed in a plane running perpendicular to the axis of the bottom nozzle. The additional nozzles are distributed about the circumference of a circle within the plane and coaxial with the axis of the bottom nozzle. The axes of the additional nozzles all intersect at a point on the axis of the bottom nozzle below the plane of the nozzle orifices.
4 citations
Patent•
04 Sep 1985
TL;DR: In this paper, the average particle size of finely powdered vitrified carbon was adjusted to a specified value and the standard deviation of the particle size distribution was adjusted as a specified % of the average particles size.
Abstract: PURPOSE:To obtain a lubricity providing agent with superior heat resistance by adjusting the average particle size of finely powdered vitrified carbon to a specified value and the standard deviation of the particle size distribution to a specified % of the average particle size. CONSTITUTION:Lumps or sticks of vitrified carbon are ground with a hammer mill, a crusher, a jet mill or the like, and classification is carried out to obtain finely powdered vitrified carbon of 0.1-1.5mum average particle size. The standard deviation of the particle size distribution is <=30% of the average particle size. The finely powdered vitrified carbon is dispersed in a proper solvent and used as a lubricity providing agent. The vitrified carbon may be mixed with a binder and a proper solvent.
2 citations
Patent•
13 Aug 1985
TL;DR: In this paper, the authors propose to observe sectional structures of fine particles easily in high magnification by milling finely cokes having specified remaining volatile component to the average particle diameter less than the average value and less than a specified value.
Abstract: PURPOSE:To observe sectional structures of fine particles easily in high magnification by milling finely cokes having specified remaining volatile component to the average particle diameter less than the average value and less than a specified value, press molding together with a sample and using said body. CONSTITUTION:The cokes having >=4wt% remaining volatile component is necessary, but 8-15wt% is most suitable for the volatile component quality. The smaller the particle diameter of the cokes, the higher the strength of the embedded sample, a gringing utilizing shearing force, e.g. using automated mortar is preferable to the finely milling mode. The powders manufactured by impacting crushing mode e.g. such as jet mill show the large spring back immediately after the molding, consequently are easy to crack during the mold releasing and unsuitable. In this case, if the grinding is performed by automated mortar in a short time, the crack occurrence during mold releasing can be suppressed in some extent. In normal temp. forming, >=1,000kg/cm molding pressure is preferable. For preventing the oxidation, <=200 deg.C heating temp. is preferable.
1 citations
Patent•
[...]
28 Feb 1985
TL;DR: In this article, a pulverizer for coal is described, in which a sleeve is mounted within the pulverization chamber so that the coarser particles which pass upwardly through the sleeve flow downwardly in the annular space between the sleeve and the chamber side wall, to be re-entrained by the nozzles and projected again into the sleeve for further impacting.
Abstract: A pulverizer for pulverizing solid material such as coal in which the chamber of the pulverizer has jets of fluid projected thereinto at high speed to cause the particles to impact against one another to effect the pulverizing and in which a sleeve is mounted within the pulverizer chamber so that the coarser particles which pass upwardly through the sleeve flow downwardly in the annular space between the sleeve and the chamber side wall, to be re-entrained by the nozzles and projected again into the sleeve for further impacting.