PROBLEM TO BE SOLVED: To provide spherical nickel fine powder having excellent crystallinity, and in which the intrusion of coarse particles is remarkably fewer than that in the conventional one, and an industrially easy production method therefor.SOLUTION: The production method includes: a raw material preparation step of preparing a nickel raw material in such a manner that the content of sulfur reaches 0.1 to 0.5 mass%; a pulverization step of vaporizing the nickel raw material by thermal plasma in a reducing atmosphere to condensate nickel vapor so as to be pulverized; a coarse particle removal step of continuously introducing the obtained pulverized nickel into a water-cooled jacket type cyclone to remove the coarse particles; a recovering step of recovering the pulverized nickel; and a gradual oxidation step of holding the recovered pulverized nickel in an weakly acidic inert gas atmosphere so as to gradually oxidize the surface of the pulverized nickel to obtain nickel fine powder.

Nickel fine powder and method for producing the same

An aim of the invention is to provide a nickel micro powder which is spherical and has excellent crystallinity and oversize particle mixing ratio that is greatly reduced than that of the prior-art product. The manufacturing method of the nickel micro powder comprises the following steps: raw material preparing step of preparing a nickel raw material through a mode that the sulfur content is 0.1-0.5% by mass; a micronizing step of gasifying the nickel raw material through hot plasma in a reducing gas environment for condensing the nickel steam and micronizing; an oversize particle removing step of continuously guiding the obtained micronized nickel into a water cooling jacket type cyclone separator for removing the oversize particles and cooling the micronized nickel; a recycling step of recycling the micronized nickel; and a slow oxidizing step of keeping the recycled micronized nickel in a weak oxidative non-active gas environment so the surface of the micronized nickel is slowly oxidized for obtaining the nickel micro powder.

Nickel micro powder and manufacturing method thereof

To provide an apparatus and a method of producing fine particles capable of increasing evaporation efficiency of a material, increasing the production of fine particles and reducing costs by heating the inputted material by a gas heated by thermal plasma A fine particle production apparatus includes a vacuum chamber, a material feeding device connected to the vacuum chamber and feeding material particles from a material feeding port into the vacuum chamber, electrodes arranged in the vacuum chamber for generating plasma and a collection device connected to the vacuum chamber and collecting fine particles, which produces the fine particles from the material by generating electric discharge inside the vacuum chamber, in which the collection device and the material feeding device are connected by piping, and a material heating and circulation device which heats the material by heat of a gas inside the chamber heated by the plasma through the piping is provided

Fine particle production apparatus and fine particle production method

PROBLEM TO BE SOLVED: To provide a compact direct contact type heat exchanger of low pressure loss.SOLUTION: In this direct contact type heat exchanger 1, gas ascending sections 21 as spaces to allow a gas to ascend, are respectively disposed between a first side 8a of a shelf board 8 of m-stage (m is integer of 2 or more) and an inner surface of a housing 2, and between a first side 10a and a second side 10b not intersecting the first side 10a, of an intermediate board 10 and the inner surface of the housing 2. Second sides 8b not intersecting the first sides 8a of the shelf boards 8 of m-stage are respectively disposed on the inner surfaces of the housing 2 while being vertically staggered, so that the gas is allowed to flow out from a gas outlet 4 while meandering and ascending from a gas inlet 3. Water descending sections as spaces to allow humidification water 20 temporarily retained on the shelf boards 8 of m-stage and the intermediate boards 10, to descend, are respectively disposed between the shelf board 8 of m-stage and the inner surface of the housing 2, and between the intermediate board 10 and the inner surface of the housing 2.

Direct contact type heat exchanger and polymer electrolyte fuel cell system

PROBLEM TO BE SOLVED: To suppress adherence of a thermally treated product onto an inner wall surface of a discharge container which is caused by arc discharge and make it possible to continuously manufacture the thermally treated product.SOLUTION: There is provided particulate material manufacturing apparatus comprising: a discharge container 10 in which a plurality of discharge electrodes 14 are two-dimensionally or three-dimensionally arranged; and an AC power source 18 which applies alternating current having a phase difference to the discharge electrodes 14 to generate arc discharge between the discharge electrodes 14. The apparatus has: material supply means (20) for supplying a particulate material (32) to an arc discharge generating part 16 by the discharge electrodes 14 together with inert gas; shield gas forming means (24) for forming a shield gas flow 26 of inert gas flowing so as to surround an inert gas flow (22) containing a thermally treated product caused by arc discharge, in which the shield gas flow flows from the arc discharge generating part 16 toward an outflow port 12 of the discharge container 10; and recovery means (30) of the thermally treated product caused by arc discharge which flowed out from the discharge container 10 together with inert gas.

Particulate material manufacturing apparatus

PROBLEM TO BE SOLVED: To provide a method for producing fine particles, in which the fine particles excellent in dispersibility can be produced and recovered in high efficiency and to provide a production apparatus to be used in the method for producing fine particles SOLUTION: The method for producing fine particles comprises the steps of: treating a fine particle raw material with thermal plasma to obtain vapor of a fine particle component; condensing the obtained vapor of the fine particle component at the tail of a plasma flame to produce the fine particles outside the plasma flame; conveying the produced fine particles to a fine particle recovery unit by using a gas current to recover the conveyed fine particles The gas current is a whirling current of a gas whirling outside the plasma flame so that the produced fine particles are conveyed from the tail of the plasma flame to the outside of the plasma flame COPYRIGHT: (C)2010,JPO&INPIT

Method for producing fine particle and production apparatus to be used therein

PROBLEM TO BE SOLVED: To provide a feed well for thickeners which is a cylindrical feed well vertically provided to the upper part in a thickener, which sediments and concentrates a fed slurry, at the position on the circle concentric to the rotary shaft of a rake and constituted so as to achieve results such that the slurry and additive fed to the feed well are sufficiently mixed in the feed well even when the supply amount or concentration of the slurry rises largely and the slurry in the feed well flows out to the sedimentation and concentration part of the lower part in the thickener without being drifted, by a simple means. SOLUTION: The feed well for thickeners is characterized by including a slurry feed pipe sending the slurry subjected to sedimentation and concentration to the upper part position of the feed well and a rectification plate provided to the part just under the outlet of the slurry feed pipe in a shelf-like state so as to produce the revolving stream of the slurry, which is discharged from the outlet of the slurry feed pipe, along the inner wall of the feed well. COPYRIGHT: (C)2010,JPO&INPIT

Feed well for thickener

The countercurrent direct-heating-type heat exchanger that is able to suppress drift in the case when a fluid to be heated is supplied, to prevent local abrasion of the members and also to carry out efficient heat exchange. The countercurrent direct-heating-type heat exchanger equipped with a feed pipe, a feed nozzle, ring-like straightening plates and umbrella-type dispersing plates of the above fluid to be heated, characterized in that the above feed nozzle has the shape of a pipe having a circular cross section and the dimension satisfying the following formula (1) and formula (2): Ln/Dn ≧1   Formula (1) (wherein, Ln indicates the length of the feed nozzle; and Dn indicates the inside diameter of the feed nozzle) 1.5≦ Sp/Sn ≦2.0   Formula (2) (wherein, Sp indicates the inner cross-sectional area of the feed pipe; and Sn indicates the inner cross-sectional area of the feed nozzle).

Countercurrent direct-heating-type heat exchanger

PROBLEM TO BE SOLVED: To provide a countercurrent type direct heating heat exchanger capable of suppressing drift upon supplying a heating fluid, preventing local wear of a member, and efficiently performing heat exchange SOLUTION: The countercurrent type direct heating heat exchanger incorporates a supply pipe 1 for the heating fluid, a supply nozzle 2, a ring-shaped rectifying plate 3, and an umbrella type dispersion plate 4 The shape of the supply nozzle 2 is a pipe shape having a circular cross section, its dimensions satisfying expressions (1) and (2), wherein expression (1): Ln/Dn≥1 in which Ln is a length of the supply nozzle 2 and Dn is an inner diameter of the supply nozzle 2, and expression (2): 15≤Sp/Sn≤20 in which Sp is an internal cross section of the supply pipe 1 and Sn is an internal cross section of the supply nozzle 2 COPYRIGHT: (C)2010,JPO&INPIT

Yukihito Sasaki

Papers

Method for producing fine particle and production apparatus to be used therein

Feed well for thickener

Countercurrent direct-heating-type heat exchanger

Countercurrent type direct heating heat exchanger