EP0124023B1 - Procédé et installation d'atomisation de métaux liquides pour l'obtention de poudres fines - Google Patents

Procédé et installation d'atomisation de métaux liquides pour l'obtention de poudres fines Download PDF

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Publication number
EP0124023B1
EP0124023B1 EP84104377A EP84104377A EP0124023B1 EP 0124023 B1 EP0124023 B1 EP 0124023B1 EP 84104377 A EP84104377 A EP 84104377A EP 84104377 A EP84104377 A EP 84104377A EP 0124023 B1 EP0124023 B1 EP 0124023B1
Authority
EP
European Patent Office
Prior art keywords
gas
jet
annular
gas jet
liquid metal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP84104377A
Other languages
German (de)
English (en)
Other versions
EP0124023A1 (fr
Inventor
Thomas Dr. Duerig
Marcel Dr. Escudier
Jakob Dr. Keller
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BBC Brown Boveri AG Switzerland
Original Assignee
BBC Brown Boveri AG Switzerland
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BBC Brown Boveri AG Switzerland filed Critical BBC Brown Boveri AG Switzerland
Publication of EP0124023A1 publication Critical patent/EP0124023A1/fr
Application granted granted Critical
Publication of EP0124023B1 publication Critical patent/EP0124023B1/fr
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
    • B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
    • B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
    • B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
    • B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
    • B22F2009/088—Fluid nozzles, e.g. angle, distance

Definitions

  • the invention relates to a device for atomizing liquid metals according to the preamble of claim 1 and to a method according to the preamble of claim 2.
  • Metal atomization for the production of a powder for powder metallurgical and other applications has been published for a long time and is known from a wide range of specialist literature.
  • the process of atomization using a gas jet is preferred.
  • gas jet air, nitrogen, noble gas
  • Known devices for gas jet atomization have, as an essential tool, a centrally symmetrical body for guiding the liquid metal to be atomized (metal jet) and the atomizing medium (gas jet), a so-called nozzle. Such devices are intended to achieve the most complete possible resolution of the liquid metal jet into individual small droplets.
  • a device has already been proposed (cf., for example, US Pat. No. 2,997,245) which, in a rotationally symmetrical body, has an annular inlet channel for the gaseous atomizing medium, which is directed obliquely upwards against the body axis an imaginary cone-shaped taper (circumferentially distributed) (tapered nozzles with a circular cross-section) or in a single cone-shaped, also sloping upwards (as a nozzle). Opposite the individual nozzles or the annular gap there are recesses arranged symmetrically to the latter and so-called resonance chambers on both sides of these recesses.
  • the structure of this device is comparatively complicated, unclear and therefore hardly accessible to the gas dynamic calculation.
  • the abrupt deflection of the gas jet, the series connection of confusors and diffusers is also associated with considerable energy losses.
  • the metal powders produced with such a device leave something to be desired in various respects.
  • the invention has for its object to provide a device and a method for atomizing liquid metals, by means of which extremely high cooling rates of the melt and extremely fine-grained powder particles can be achieved.
  • the gas dynamic conditions in the atomization chamber should be simple and clear and should be optimized to ensure the greatest possible disintegration of the metal.
  • 1 shows a schematic longitudinal section through a device for atomizing liquid metals.
  • 1 is a rotationally symmetrical housing with preferably cylindrical boundary surfaces.
  • the housing 1 has an annular cooling channel 2 for receiving a liquid or gaseous coolant.
  • annular chamber 3 is provided, which serves for the gas supply (atomizing agent).
  • the chamber 3 merges into a conical narrow annular gap nozzle 4 which runs coaxially with the longitudinal axis of the housing 1.
  • the housing 1 On the outlet side of the annular gap nozzle 4, the housing 1 is closed off with a stepped flange (end plate) 5.
  • the latter has a sharp annular edge 6 and an annular resonance chamber 7 on its inner (bore) side.
  • a sleeve 8 In the central longitudinal bore of the housing 1 there is a sleeve 8, the outlet end of which is conical is cut and has a sharp trailing edge 9.
  • the sleeve 8 provided with a bore 10 for receiving the liquid metal to be atomized has a thread 11 at its inlet end, via which it is held on the housing 1 by means of a round nut 12.
  • the sleeve 8 is displaceable in its longitudinal direction with respect to the housing 1 and can thus be clamped in any position relative to the latter.
  • exit edge 9 can be varied with respect to the position of the annular gap nozzle 4 and the annular edge 6.
  • the components 1, 5, 8 and 12 are advantageously made of metallic materials with graded heat resistance and different thermal conductivity.
  • the sleeve 8 can also consist of a heat-resistant material such as ceramic material.
  • the invention is in no way material-specific; their characteristic geometry can in principle be transferred to all suitable material combinations.
  • Fig. 2 shows a longitudinal section through an atomization zone of the device on an enlarged scale.
  • the reference numerals correspond exactly to those in FIG. 1.
  • the exit edge 9 of the sleeve 8 is set back advantageously compared to the imaginary continuation of the conical movement surface of the annular gap nozzle 4, so that the exit cone of the sleeve 8 is not in alignment with the cone of the annular gap nozzle.
  • FIG 3 shows a diagram of the gas dynamic conditions in the atomization zone.
  • the sound intensity in decibels is plotted as a function of frequency in kHz.
  • Nitrogen under a pressure of 80 bar was used as the atomizing agent.
  • the components 1, 5, 8 and 12 according to FIG. 1 were made of steel, the actual dimensions being approximately half as large as shown in FIG. 1.
  • the sleeve 8 was set in such a way that its exit edge 9 was set back approximately 1.2 mm with respect to the imaginary section of the extension of the conical jacket corresponding to the annular gap nozzle 4 with the jacket of the cylindrical bore 10 of the sleeve 8 (see FIG. 2! .
  • the annular cooling channel 2 of the housing 1 was cooled with water, while the annular chamber 3 serving for gas supply was pressurized with nitrogen at 80 bar pressure as an atomizing agent. As can be seen from the diagram in FIG.
  • the invention is not exhausted in the description of the figures or in the aforementioned exemplary embodiment.
  • an inert gas e.g. B. argon or helium can be used.
  • the average total opening angle of the imaginary cone of the gas jet should be approximately 35 to 55 °.
  • the advantageous effect of the new atomization device consists in the generation of a gas jet which moves at least at the speed of sound against the liquid metal jet and which, in addition to a more or less continuous band, has clearly perceptible, high-intensity discrete sound frequencies. This is achieved by special training of a resonance room and a targeted guidance of the gas emitters.

Landscapes

  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)
  • Nozzles (AREA)
  • Glanulating (AREA)

Claims (3)

1. Dispositif d'atomisation de métaux liquides pour la production d'une poudre fine, se composant d'un corps à symétrie de révolution, qui comporte des canaux pour l'admission du métal liquide à atomiser ainsi que du gaz servant à l'atomisation et qui est pourvu d'un canal de refroidissement (2) annulaire et d'une chambre (3) annulaire servant à l'alimentation en gaz, caractérisé en ce que, dans un corps (1) limité par des surfaces latérales cylindriques, il est prévu une tuyère à fente annulaire (4) pourvue de surfaces limites coniques qui convergent dans le sens de l'écoulement, avec un angle total moyen d'ouverture du cône imaginaire de 35 à 55°' pour produire un jet de gaz conique creux convergent dans le sens d'écoulement du métal liquide, en ce qu'en outre le corps (1) est, à sa face d'extrémité tournée vers la sortie du gaz de la tuyère (4), à l'endroit situé après la section de gaz la plus étroite dans le sens de l'écoulement, terminé par une bride (5) présentant une chambre de résonance (7) de forme conique creuse, située à l'extérieur de et approximativement perpendiculaire au jet de gaz et pourvue d'une arête vive (6) annulaire disposée à l'extérieur, et en ce que, dans l'alésage longitudinal central du corps (1), se trouve une douille (8) pourvue à son extrémité inférieure d'une arête de sortie (9) avec une surface limite conique et à son extrémité supérieure d'un filet (11), coulissante et réglable en direction longitudinale et fixée au corps (1) au moyen d'un écrou rond (12), destinée à recevoir le jet de métal liquide parcourant l'alésage (10).
2. Procédé d'atomisation de métaux liquides pour produire une poudre fine, dans lequel un jet de métal liquide est désintégré par un jet de gaz annulaire qui l'enveloppe, lui est concentrique et est dirigé vers son intérieur, et qui est modulé par des oscillations sonores, caractérisé en ce que le jet de gaz contient, en plus d'une bande continue de fréquences sonores, au moins encore un fréquence sonore discrète dont l'intensité est supérieure d'au moins 5 décibels à la moyenne de celle de la bande continue et dont l'amplitude de pression atteint au moins la même valeur que la pression stationnaire du gaz propulseur exercée pour produire le jet de gaz et en ce que le jet de gaz est étalé en éventail selon une surface conique imaginaire convergente dans le sens de l'écoulement vers le sommet de celle-ci et vers l'axe du jet de métal liquide, le cône imaginaire présentant un angle d'ouverture total de 35° à 55°.
3. Procédé suivant la revendication 2, caractérisé en ce que le jet de gaz contient au moins 3 fréquences sonores discrètes dépassant d'au moins 10 décibels la bande continue, dans le domaine de fréquences de 10 kHz à 200 kHz.
EP84104377A 1983-05-03 1984-04-18 Procédé et installation d'atomisation de métaux liquides pour l'obtention de poudres fines Expired EP0124023B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH2389/83 1983-05-03
CH238983 1983-05-03

Publications (2)

Publication Number Publication Date
EP0124023A1 EP0124023A1 (fr) 1984-11-07
EP0124023B1 true EP0124023B1 (fr) 1987-11-25

Family

ID=4232642

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84104377A Expired EP0124023B1 (fr) 1983-05-03 1984-04-18 Procédé et installation d'atomisation de métaux liquides pour l'obtention de poudres fines

Country Status (5)

Country Link
US (2) US4575325A (fr)
EP (1) EP0124023B1 (fr)
JP (1) JPS59206067A (fr)
CA (1) CA1228459A (fr)
DE (2) DE3319508A1 (fr)

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US4780130A (en) * 1987-07-22 1988-10-25 Gte Laboratories Incorporated Process to increase yield of fines in gas atomized metal powder using melt overpressure
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DE4022648C2 (de) * 1990-07-17 1994-01-27 Nukem Gmbh Verfahren und Vorrichtung zur Herstellung von kugelförmigen Teilchen aus flüssiger Phase
US5226948A (en) * 1990-08-30 1993-07-13 University Of Southern California Method and apparatus for droplet stream manufacturing
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US5268018A (en) * 1991-11-05 1993-12-07 General Electric Company Controlled process for the production of a spray of atomized metal droplets
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RU2559080C1 (ru) * 2014-03-11 2015-08-10 Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Национальный исследовательский Томский государственный университет" (ТГУ) Способ получения металлических порошков распылением расплавов
RU2554257C1 (ru) * 2014-03-11 2015-06-27 Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Национальный исследовательский Томский университет" (ТГУ) Форсунка для распыления расплавленных металлов
CN110181069B (zh) * 2019-07-08 2023-01-31 华北理工大学 采用气雾化法制备高氮钢粉末的方法

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Also Published As

Publication number Publication date
US4640806A (en) 1987-02-03
CA1228459A (fr) 1987-10-27
US4575325A (en) 1986-03-11
EP0124023A1 (fr) 1984-11-07
JPS59206067A (ja) 1984-11-21
DE3467726D1 (en) 1988-01-07
DE3319508A1 (de) 1984-11-08
JPH049105B2 (fr) 1992-02-19

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