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Showing papers on "Jet mill published in 2009"


Journal ArticleDOI
TL;DR: In this article, a fine grinding testwork of talc was carried out in a jet mill by varying the feed rate, classifier rotational speed, and grinding pressure at five levels.

51 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of pre-existing flaws on mechanical material properties of crystals of a model material, sodium chloride, from different sources have been investigated using optical microscopy, nanoindentation, and powder compaction.

35 citations


Journal ArticleDOI
TL;DR: In this article, the packing fraction and circularity of limestone powders were determined by analyzing scanning electron microscope (SEM) photographs of the particles using an image analyzer and the point counting method.
Abstract: The fluidity and flow mechanism of suspensions containing low-heat Portland cement, limestone powders with different characteristics, and a polycarboxylate-based superplasticizer have been studied. Limestone powders with six different degrees of grinding were prepared using a ball mill and a jet mill. The circularity of the limestone powder particles was determined by analyzing scanning electron microscope (SEM) photographs of the particles using an image analyzer and the point counting method. A computer program for determining the packing fraction of powder particles directly from the particle size distribution was written and the packing fraction was calculated. It was made clear quantitatively that the packing fraction and circularity of limestone powder particles significantly affected the fluidity of the suspensions. The addition of finely ground limestone powders prepared by jet mill increased the fluidity of suspensions. The fluidity of low-heat Portland cement paste with finely ground limestone powders prepared by jet mill at a water-to-powder ratio of 0.225 is as same as the fluidity of low-heat Portland cement paste at a water-to-powder ratio of 0.30. The fluidity of a suspension could be approximated with accuracy using the packing fraction and the circularity of powders. Particles with a circular shape and a high packing fraction result in increased fluidity. The ratio of the contribution made by the packing fraction to this improvement in fluidity to that of shape ranged from 1:1 to about 1:2.

24 citations


Journal ArticleDOI
TL;DR: In this paper, an ultra-fine grinding of ground limestone was carried out in jet mill using four levels of classifier rotational speed and grinding pressure, and the holdup amount was determined during the grinding process, while the feed rate was kept constant at 8 kg/h.

23 citations


Patent
21 Oct 2009
TL;DR: In this article, an automatic control device for continuous powdery material feeding under a pressurized production condition, which adopts the technical scheme that a middle hopper serves as a pressure transition container, an upper hopper, the middle hpper and a lower hpper are connected in series, a conveyor belt and a material amount adjusting mechanism are mounted in the lower hopper; a weighting sensor is arranged in a mill; and level switches are mounted on the hoppers for realizing the emptying of the hopper and the continuous automatic feeding of powdery materials through a programmable
Abstract: The utility model discloses an automatic control device for continuous powdery material feeding under a pressurized production condition, which adopts the technical scheme that a middle hopper serves as a pressure transition container; an upper hopper, the middle hopper and a lower hopper are connected in series; a conveyor belt and a material amount adjusting mechanism are mounted in the lower hopper; a weighting sensor is arranged in a mill; and level switches are mounted on the hoppers for realizing the emptying of the hoppers and the continuous automatic feeding of powdery materials through a programmable controller. The utility model has the advantages that the long-term stable running of a jet mill is realized; powdery materials can enter a central milling area of the mill with continuous and uniform amount as well as small instant flow fluctuations, and the continuous automatic control on the feeding amount is achieved, thereby facilitating the stability of a fluidized bed of the mill; and meanwhile, the device can ensure good particle size of milled materials, and improve the product quality and the equipment utilization rate while reducing the consumption of pressure-maintaining nitrogen or argon as well as the production cost.

11 citations


Patent
16 Apr 2009
TL;DR: In this paper, a method and jet mill apparatus for generating fine particles by means of a jet mill with an integrated dynamic air classifier including a classifying wheel and a classifier shaft and classifier housing is presented.
Abstract: A method and jet mill apparatus for generating fine particles by means of a jet mill with an integrated dynamic air classifier including a classifying wheel classifying wheel shaft and classifier housing, wherein between the classifying wheel and classifier housing a classifier gap is formed and between the classifying wheel shaft and the classifier housing a shaft passage is formed, wherein gap flushing of classifier gap or shaft passage takes place with compressed gases of low energy content, and wherein comminution jet inlets are present which are charged with energy-rich superheated steam. Through the invention a dynamic air classifier explained above and a corresponding operating method therefor are additionally created.

10 citations


Patent
04 Mar 2009
TL;DR: In this article, the authors describe a grading device for a dry ball mill, which consists of a driving mechanism, a feeder, a stirring shaft, a ball mill crushing cavity, a cyclone collector, a bag dust collector, an induced draught fan and an air inlet.
Abstract: The utility model relates to a grading device for a dry ball mill, which consists of a driving mechanism, a feeder, a stirring shaft, a ball mill crushing cavity, a grader host machine I , a grader host machine II , a cyclone collector, a bag dust collector, an induced draught fan and an air inlet, wherein the lower end of the feeder is connected with the ball mill crushing cavity; the inner center of the ball mill crushing cavity is provided with the stirring shaft which is connected with the driving mechanism; the upper end of the ball mill crushing cavity is connected into a whole with the grader host machine I ; and the grader host machine I , the grader host machine II , the cyclone collector, the bag duct collector and the induced draught fan are connected with each other in turn through blast pipes. The grading device for the dry ball mill crushes and grades objects in advance by combination of the dry ball mill and an air classifier; micro powder particles which are crushed by the grading device have unique shapes, and are particularly suitable to be grinded and cut; the shape is different from a round taper angle when the micro powder particles are crushed by a jet mill and is also different from the shape of a strip, a plate and a needle when the micro powder particles are crushed by a Raymond mill, and is an equiareal figure with a taper angle, so that the micro powder particles are suitable to be used as special cutting edge materials for cutting a wafer cell slice; and the odd yield is as high as 75 percent.

9 citations


Patent
10 Jun 2009
TL;DR: In this paper, a two-way rotary ball mill was used to extract nanometer bamboo charcoal powder from an earth kiln, where the carbonization temperature is between 1,200 and 1,600 DEG C, the carbonisation time is between 24 and 48 hours, carbide is crushed by a flat fluid jet mill into the particle size which is less than or equal to 1.5 um, and then the mixture continues to be ground in the ball mill until the average particle size of the mixture reaches 60 to 300 nm through the detection.
Abstract: The invention discloses nanometer bamboo charcoal powder and a preparation method thereof. The method is characterized in that bamboo charcoal baked by an earth kiln is used, then a high-temperature electric box electric furnace is used for carbonization, the carbonization temperature is between 1,200 and 1,600 DEG C, the carbonization time is between 24 and 48 hours, carbide is crushed by a flat fluid jet mill into the particle size which is less than or equal to 1.5 um, and then the carbide, a coupling agent, an anion surfactant, a non-ionic interfacial agent-sodium polyacrylate salt used as a dispersant, a modified polysiloxane defoaming agent, and deionized water are mixed evenly and then are placed in a two-way rotary ball mill for grinding. The rotating speed of the ball mill is between 4,000 and 4,500r/m, and the grinding time is between 48 and 96 hours. A grinding mixture is diluted by the deionized water, is subjected to ultrasonic treatment, and is tested by a laser particle size analyzer (the measurement range is between 3 and 3,000 nm), the particle size and the particle size distribution are measured by a wet method, and the mixture is regarded not to reach the standard when the particle size is more than 300nm. Then the mixture continues to be ground in the ball mill until the average particle size of the mixture reaches 60 to 300 nm through the detection, and then is dried to obtain the nanometer bamboo charcoal powder.

9 citations


Journal ArticleDOI
TL;DR: In this paper, in-situ carbon nanotubes (CNT) agglomeration was studied at ambient conditions using a target/nozzle configuration to assess the feasibility of in-Situ CNT grinding during synthesis in a pilot reactor.

6 citations


Patent
10 Jun 2009
TL;DR: In this paper, a method for preparing chromatic timing powder is described, which consists of a resin is dissolved in organic solvent, added with dye and filler, evenly stirred and ground by a high-speed dispersing machine or sand mill to obtain liquid intermediate with evenly dispersed dye, and the evenly dispersed liquid is pressurized, sprayed, dried, and granulated, or roasted, dried and crushed by a target type jet mill.
Abstract: The invention provides a method for preparing chromatic timing powder. The method comprises: resin is dissolved in organic solvent, added with dye and filler, evenly stirred and ground by a high-speed dispersing machine or sand mill to obtain liquid intermediate with evenly dispersed dye and filler; the evenly dispersed liquid is pressurized, sprayed, dried and granulated, or roasted, dried and crushed by a target type jet mill to obtain the chromatic timing powder. For the chromatic timing powder, the particle size is between 0.5 and 10 micrometers, and the pigment binder ratio is between 50 and 1,000 percent. The chromatic timing powder can be conveniently added to coating base powder to prepare powder coating.

6 citations


Patent
29 Jan 2009
TL;DR: In this article, the carbon fiber article is cut into a small size, ground, and finely pulverized to obtain a carbon fiber fine particle having an average diameter of shorter than 10 μm.
Abstract: PROBLEM TO BE SOLVED: To obtain a carbon fiber fine particle which is finely pulverized to have an average diameter of shorter than 10 μm from a substandard article generated between manufacturing processes of carbon fiber, an industrial waste of carbon fiber, and a carbon fiber object such as a waste material article or the like. SOLUTION: The carbon fiber article is cut into a small size, ground, and finely pulverized to obtain the carbon fiber fine particle having an average diameter of shorter than 10 μm. Moreover, the manufacture method and apparatus of the carbon fiber fine particle are characterized in that in obtaining the carbon fiber fine particle, the carbon fiber is cut into a small size, the carbon fiber cut into a small size is suctioned, collected, stored and finely pulverized by either of a jet mill, a ball mill, a bead mill grinder or the like which utilizes impact friction force making the carbon fiber fine particle before the utilization. COPYRIGHT: (C)2009,JPO&INPIT

Patent
20 Aug 2009
TL;DR: In this paper, a method for efficiently and precisely setting jet mill grinding conditions for stably obtaining a powder having a specified grain size distribution is proposed, where a plurality of factors influencing a grinding process are selected, then a plurality levels are selected for every selected factor and the selected factors and selected level are allotted to an orthogonal arrangement table according to an experimental planning method.
Abstract: PROBLEM TO BE SOLVED: To provide a method for efficiently and precisely setting jet mill grinding conditions for stably obtaining a powder having a specified grain size distribution SOLUTION: First, a plurality of factors influencing a grinding process are selected, then a plurality of levels are selected for every selected factor and the selected factor and the selected level are allotted to an orthogonal arrangement table according to an experimental planning method, and the grain is test-ground in accordance with grinding conditions based on the orthogonal arrangement table Further, the particle diameter (D 50 ) which accounts for 50% of the integrated grain size distribution (volume standard) from the small particle diameter side of the obtained powder, and/or the particle diameter (D 90 ) which accounts for 90% of the integrated grain size distribution (volume standard) from the small particle diameter side of the obtained powder, is measured Then, the scatter analysis of the measurements is performed, then the promising factors to D 50 and/or D 90 are specified, and the point estimation and the interval estimation of D 50 and/or D 90 are carried out at each level of the specified promising factors Further, the desired jet mill grinding conditions are decided according to the estimate and the confidence interval sought by the point estimation and the interval estimation COPYRIGHT: (C)2011,JPO&INPIT

Patent
23 Apr 2009
TL;DR: In this article, a classifying plate is mounted on a casing of a jet mill and a protruded part is formed in such a manner that a ratio of the maximum thickness (d2) in the radial direction of the crushing chamber 14/the maximum inside diameter r of the chamber in falls within the range of 0.05-0.15.
Abstract: PROBLEM TO BE SOLVED: To provide a jet mill for producing powder allowing a dispersion degree in density of a molded body to be reduced, even if physical properties of raw material particles such as BET specific surface area and pulverization condition of the raw material particles vary, and a production method of the fine powder of translucent alumina raw material using the jet mill. SOLUTION: A classifying plate 15 is mounted on a casing 2 of the jet mill 1. The classifying plate 15 is provided with a protruded part 6 protruded into a crushing chamber 14 when mounted on the casing 2. The protruded part 6 is formed in such a manner that a ratio of the maximum thickness (d2) of the protruded part 6 in the radial direction of the crushing chamber 14/the maximum inside diameter r of the crushing chamber in falls within the range of 0.05-0.15. COPYRIGHT: (C)2009,JPO&INPIT

Patent
05 Aug 2009
TL;DR: In this article, a jet mill constant charge-level automatic feeding system has been described, which consists of an automatic feeder and a driving motor, and further comprises a charge level measuring probe which detects material concentration in a grinding chamber of a jet-mill in real time, and a frequency-changer which analyzes and processes signals detected by the probe, and correspondingly controls the rotary speed of the driving motor.
Abstract: The utility model discloses a jet mill constant charge-level automatic feeding system, which comprises an automatic feeder and a driving motor which drives the automatic feeder, and further comprises a charge level measuring probe which detect material concentration in a grinding chamber of a jet mill in real time, and a frequency-changer which analyzes and processes signals detected by the charge level measuring probe, and correspondingly controls the rotary speed of the driving motor, and the charge level measuring probe is an analogy signal sensor, and is connected with the frequency-changer. The jet mill constant charge-level automatic feeding system has reasonable structure, simple use and operation, even particle sizes of grinded powder and high magnetic property, which can effectively solve the problem of dynamic constant charge-level automatic feeding of a jet mill.

Patent
06 May 2009
TL;DR: In this article, an R-T-B system alloy powder treatment method for radiation magnetic rings was proposed, which is uniform in the density of the radiation ring, high in one-time molding rate and wide in pressure application range, and improves surface magnetic uniformity.
Abstract: The invention provides an R-T-B system alloy powder treatment method for radiation magnetic rings. The method comprises the following steps: raw alloy is melted in vacuum or inert gas so as to cast an ingot; a raw alloy ingot is subjected to coarse or hydrogen crushing in inert atmosphere; any two substances selected from polyethylene oxide composite polymers, fatty acid, fatty acid derivatives and hydrocarbon are added to and mixed with powder after coarse or hydrogen crushing; alloy coarse powder is subjected to micro-grinding in a nitrogen environment by use of a jet mill; the alloy powder is annealed in inert gas, vacuum or reducing atmosphere; carbonyl iron powder and at least one alicyclic hydrocarbon are added to and mixed with the annealed alloy powder; the mixed powder is taken to form an annular formed body in a magnetic field; the annular formed body is sintered in vacuum or inert gas atmosphere. The method has the advantages that the method is uniform in the density of the radiation ring, high in one-time molding rate and wide in pressure application range, increases the magnetic energy product of the radiation ring, and improves surface magnetic uniformity.

Patent
06 Aug 2009
TL;DR: In this article, a method for feeding a raw material for fine particle (nanoparticle) manufacture into a heating furnace by which fine particles having a particle size distribution sharper than that of those prepared according to conventional techniques can be efficiently manufactured and which can be suitably applied to a fine particle manufacturing apparatus.
Abstract: PROBLEM TO BE SOLVED: To provide a method for feeding a raw material for fine particle (nanoparticle) manufacture into a heating furnace by which fine particles (nanoparticles) having a particle size distribution sharper than that of those prepared according to conventional techniques can be efficiently manufactured and which can be suitably applied to a fine particle manufacturing apparatus. SOLUTION: This method for feeding a raw material into a heating furnace is used for feeding a raw material for fine particle manufacture into a heating furnace and is characterized in that the raw material for fine particle manufacture is deagglomerated, pulverized and dispersed using a jet mill and then fed into the heating furnace. As an example of the material for fine particle manufacture, granules containing metal or nonmetal in the form of a simple substance, a compound or a mixture can be cited. COPYRIGHT: (C)2009,JPO&INPIT

Patent
03 Mar 2009
TL;DR: A fluoropolymer material exhibiting an increased hydrophilicity prepared by processing the material in a jet mill is described in this article, where the material is shown to have an increased hyphilicity.
Abstract: A fluoropolymer material exhibiting an increased hydrophilicity prepared by processing the material in a jet mill.

Patent
13 Aug 2009
TL;DR: In this article, the authors provided a jet mill having a classification mechanism built therein which is an apparatus having a grinding chamber simple in shape and capable of developing a grinding capacity peculiar to the jet mill and constituted so as to prevent the occurrence of irregularity in particle size caused by the plunging of the coarse particles of a ground material (product) into the ground material especially at the time of nano fine grinding to enable fine grinding uniformized in grinding particle size.
Abstract: PROBLEM TO BE SOLVED: To provide a jet mill having a classification mechanism built therein which is an apparatus having a grinding chamber simple in shape and capable of developing a grinding capacity peculiar to the jet mill and constituted so as to prevent the occurrence of irregularity in particle size caused by the plunging of the coarse particles of a ground material (product) into the ground material especially at the time of nano fine grinding to enable fine grinding uniformized in grinding particle size SOLUTION: The jet mill is equipped with a casing having a grinding chamber, which has a horizontal disk-shaped internal space, formed therein in order to constitute a jet mill body, and equipped in the casing with an outlet (ground material discharge port), a raw material supply nozzle for supplying the ground material and a plurality of grinding nozzles capable of jetting high-speed air streams into the grinding chamber to form a concentrically circular vortex flow of high energy The casing is provided therein with the classification mechanism composed of a classifying nozzle for producing the concentrically circular vortex flow centering around the opening position of the outlet in the casing of the grinding chamber and a trumpet-shaped outlet opening part provided in the casing of the grinding chamber in a protruded state COPYRIGHT: (C)2009,JPO&INPIT

Patent
03 Mar 2009
TL;DR: A fluoropolymer material exhibiting an increased hydrophilicity prepared by processing the material in a jet mill or a cryogenic grinding mill is described in this article, where the material exhibits an increased hyphilicity.
Abstract: A fluoropolymer material exhibiting an increased hydrophilicity prepared by processing the material in a jet mill or a cryogenic grinding mill.

01 Jan 2009
TL;DR: In this article, a fine grinding of high purity talc in jet mill at low grinding pressure was carried out by varying the feed rate and classifier rotational speed, and the ground and sonicated particles were characterized in terms of particle size and particle size distribution.
Abstract: Fine grinding of high purity talc in jet mill at low grinding pressure was carried out by varying the feed rate and classifier rotational speed. These ground particles were sonicated in laboratory ultrasonic bath by varying the soniction period at five levels. The ground and sonicated particles were characterized in terms of particle size and particle size distribution. Mechanochemical and sonochemical effect of talc was determine via X-ray diffraction. Particle shape and surface texture of the ground and sonicated product was determined via scanning electron microscope and transmission electron microscope. The ground particle size exhibited particle size below 10 µm with narrow size distribution. The reduction of peak intensity in (002) plane indicated the layered structure has been distorted. The sonicated talc shows that the thickness of the talc particles after the sonication process is 20 nm but the lateral particle size still remains in micron range. The reduction of the XRD peak intensity for (002) plane and thickness of sonicated talc as shown in SEM and TEM micrographs proves that fine grinding and sonication process produces talc nanosheets.

Proceedings ArticleDOI
31 Mar 2009
TL;DR: Numerical simulation technology combined with flow testing measured could promote the optimization design for the fluidized bed opposed superfine jet mill.
Abstract: The flow field in the chamber of a fluidized bed op-posed superfine jet mill was numerically simulated by standard k-e turbulent model and SIMPLEC algorithm based on CFD. Path lines in the chamber of the mill, grinding region and classifying region were plotted using the predicted results. Velocity fields in grinding region and classifying region of the mill were presented in the paper. Velocity profiles at different height section along diameter were analyzed. Flow field in the chamber of the mill was measured by 5-hole probe testing system. The simulation results agree well with the experiment results. Numerical simulation technology combined with flow testing measured could promote the optimization design for the fluidized bed opposed superfine jet mill.

Patent
30 Sep 2009
TL;DR: The utility model belongs to ultra-fine grinding equipment, in particular to a composite dual-purpose jet mill as mentioned in this paper, which is characterized by a feeding nozzle arranged at the front end of a feed pipe, a feed hopper is welded on the upper portion of the feed pipe and the rear end of feed pipe is connected with a grinding chamber, and the grinding chamber connects with a base of a pancake type jet mill.
Abstract: The utility model belongs to ultra-fine grinding equipment, in particular to a composite dual-purpose jet mill. The composite dual-purpose jet mill is characterized in that a feeding nozzle is arranged at the front end of a feed pipe, a feed hopper is welded on the upper portion of the feed pipe, the rear end of the feed pipe is connected with a grinding chamber, and the grinding chamber is connected with a base of a pancake type jet mill. Besides, a target plate is arranged at the joint of the feed pipe and the grinding chamber. The utility model has the advantages that after entering the feed pipe, to-be-grinded materials are mixed with high pressure airflow and grinded after impacting the target plate in high speed, and then enter the pancake type jet mill through the grinding chamber to be grinded secondarily. By utilizing twice milling, the utility model has fine milling effect.

Patent
13 Aug 2009
TL;DR: In this article, a pulverized material is used as the binder resin for toner, which is obtained by performing once or more times the at least two steps including a melt kneading step of melting and knaving a raw material resin by a biaxial KNeading machine or the like, and a pulversizing step of cooling the molten kneaded mixture obtained by the melt kneeding step and pulverizing it by a jet mill pulverizer or a like so that the particle size of the pulverised material is ≤10 μm
Abstract: PROBLEM TO BE SOLVED: To provide a method of manufacturing toner easily reducing residual monomer without impairing necessary functions as toner with a simple structure without requiring special facilities/apparatus, and to thereby provide the toner having high safety and mitigating the problem of odor. SOLUTION: A pulverized material is used as the binder resin for toner, which is obtained by performing once or more times the at least two steps including a melt kneading step of melting and kneading a raw material resin by a biaxial kneading machine or the like and a pulverizing step of cooling the molten kneaded mixture obtained by the melt kneading step and pulverizing it by a jet mill pulverizer or the like so that the particle size of the pulverized material is ≤10 μm. Thus, the residual monomer derived from the binder resin in the toner is reduced, and the toner having high safety and mitigating the problem of odor is obtained. COPYRIGHT: (C)2009,JPO&INPIT

Journal ArticleDOI
TL;DR: In this paper, a high-pressure wet-type jet mill was used to form fine particles of LiMn 2 O 4 and LiCoO 2 to estimate the performance of Li cells containing the materials.