WO2000028098A1 - Appareil et procede destines a traiter une matiere particulaire dans une cornue rotative - Google Patents

Appareil et procede destines a traiter une matiere particulaire dans une cornue rotative Download PDF

Info

Publication number
WO2000028098A1
WO2000028098A1 PCT/US1998/011053 US9811053W WO0028098A1 WO 2000028098 A1 WO2000028098 A1 WO 2000028098A1 US 9811053 W US9811053 W US 9811053W WO 0028098 A1 WO0028098 A1 WO 0028098A1
Authority
WO
WIPO (PCT)
Prior art keywords
retort
particulate material
axle
carbon
gas
Prior art date
Application number
PCT/US1998/011053
Other languages
English (en)
Inventor
Willard E. Kemp
Original Assignee
Kemp Development Corporation
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 Kemp Development Corporation filed Critical Kemp Development Corporation
Priority to PCT/US1998/011053 priority Critical patent/WO2000028098A1/fr
Priority to EP98926136A priority patent/EP1095166A1/fr
Publication of WO2000028098A1 publication Critical patent/WO2000028098A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/08—Making spongy iron or liquid steel, by direct processes in rotary furnaces
    • 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
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/14—Treatment of metallic powder
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/34—Methods of heating
    • C21D1/53—Heating in fluidised beds
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D3/00—Diffusion processes for extraction of non-metals; Furnaces therefor
    • C21D3/02—Extraction of non-metals
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D3/00—Diffusion processes for extraction of non-metals; Furnaces therefor
    • C21D3/02—Extraction of non-metals
    • C21D3/04—Decarburising
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C10/00—Solid state diffusion of only metal elements or silicon into metallic material surfaces
    • C23C10/28—Solid state diffusion of only metal elements or silicon into metallic material surfaces using solids, e.g. powders, pastes
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C26/00—Coating not provided for in groups C23C2/00 - C23C24/00
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/24—Nitriding
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B15/00—Fluidised-bed furnaces; Other furnaces using or treating finely-divided materials in dispersion
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B7/00—Rotary-drum furnaces, i.e. horizontal or slightly inclined
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B7/00—Rotary-drum furnaces, i.e. horizontal or slightly inclined
    • F27B7/08—Rotary-drum furnaces, i.e. horizontal or slightly inclined externally heated
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B7/00—Rotary-drum furnaces, i.e. horizontal or slightly inclined
    • F27B7/20—Details, accessories, or equipment peculiar to rotary-drum furnaces
    • F27B7/36—Arrangements of air or gas supply devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B7/00—Rotary-drum furnaces, i.e. horizontal or slightly inclined
    • F27B7/20—Details, accessories, or equipment peculiar to rotary-drum furnaces
    • F27B7/38—Arrangements of cooling devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D3/00—Charging; Discharging; Manipulation of charge
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/10—Reduction of greenhouse gas [GHG] emissions
    • Y02P10/134—Reduction of greenhouse gas [GHG] emissions by avoiding CO2, e.g. using hydrogen

Definitions

  • TITLE APPARATUS AND PROCESS FOR TREATING A
  • This invention relates to an apparatus and process for treating particulate materials or powders within a rotating retort, and more particularly to such an apparatus and process in which gas is supplied to the retort to fluidize the particulate material within the rotating retort.
  • United States Patent No. 5,407,498 dated April 18, 1995 is directed to an apparatus having a retort mounted for rotation about a horizontal axis and containing a particulate material therein which is fluidized while the retort is rotated.
  • the retort is mounted in a cantilevered relation from an axle secured to one end of the generally cylindrical retort. Gas conduits extend through the end axle and gas may enter the retort and be exhausted from the retort through the gas conduit. Filters on the ends of the conduits prevent the flow of solid particles or particulate material into or out of the retort.
  • particulate material cannot be loaded into the retort or unloaded from the retort while the retort is being rotated. Further, even when the retort is not being rotated, an end cap is required to be removed in order to provide access to a port for loading or unloading the particulate material. Also, the filters shown on the inner ends of the gas conduits within the retort are easily clogged with particulate material embedded within the filters.
  • a retort which may be easily loaded with particulate material and unloaded in a minimum of time and without any loss of the particulate material by leakage or the like. It is particularly desirable to have such a loading and unloading means which may be utilized during operation of the retort while the retort is rotated.
  • metallurgical operations rely on the movement of certain elements within the solid matrix of the metal to be treated.
  • Metallurgical operations rely on chemical reaction between elements which may be physically brought together or may be induced to come together by diffusion.
  • An element is any chemical element or substance listed in the periodic table. Elements move within the solid metal by a process of diffusion. Diffusion is encouraged when an element is attracted to another element with which it is more reactive within the same contiguous metal structure. Diffusion also occurs when metals tend to form a more homogenous solid solution. Diffusion of an element from one metal to another or between a gaseous atmosphere and a metal also takes place when the materials are in intimate contact. The employment of precise pressures is often desirable to assist in this transfer.
  • fine metal particles or powders of nickel and aluminum can be intermixed and brought to a temperature well below the melting point of either metal and they will react to form a nickel aluminide intermetallic compound.
  • the combining of nickel and aluminum powders produces substantial amounts of heat. This heat can raise the temperature of operation, which further speeds the combination and eventually an uncontrolled or runaway operation can happen. Temperatures can be produced which are sufficient to melt the powders so that they agglomerate together in an undesirable mass.
  • Water atomized iron particles or powders which contain excess carbon and oxygen can be reduced by a combination of diffusion within the powder and chemical reactions at the surface.
  • the oxygen is generally an oxide on the surface of the powder but the carbon is diffused throughout.
  • a reaction is generated at the surface whereby carbon and oxygen combine to form a carbon oxygen gaseous compound and hydrogen and oxygen combine to form gaseous water.
  • Carbon within the powder migrates by diffusion to the surface and reacts with the oxygen. Heat must be added to initiate the reactions and good thermal transfer helps maintain constant temperatures which are important for a controlled reaction. In some cases, the reaction changes from endothermic to exothermic as the carbon is dissipated and hydrogen begins to combine directly with the remaining oxygen.
  • the elements in the fluidizing process to undergo a reaction will be brought into intimate contact with each other and will be held in contact for sufficient time for the chemical reaction to take place. Further, it is important that if heat is to be added during the reaction, it must be added with great uniformity so that the reaction takes place at the desired temperature. In the case of those reactions which generate heat it is even more important to have good thermal transfer so the heat can be removed from the operation to avoid an undesired rise in temperature.
  • 5,407,498 is not concerned with maintaining the exothermic or endothermic reactions of the particulate material at a precise uniform temperature during fluidizing within a rotating retort by (1) precisely controlling the addition of heat to the retort or the release of heat from the retort to match the heat loss or gain to or from the retort resulting from chemical reactions within the retort, and (2) precisely adding or injecting another material into the rotatable retort during fluidizing of the initial particulate material in the retort so that heat generated or lost matches the heat induced to or exiting from the retort as a result of said injection of particulate material.
  • the apparatus of the present invention is directed to apparatus for treating two types of workpieces.
  • Workpieces may be particulate material such as metal powders.
  • Workpieces may also be solid parts, which are placed amongst particulate materials.
  • workpiece as used in this specification and claims is interpreted as a powder or a solid part which is the subject of the treatment.
  • binder or “particulate material” as used in the specification and claims is interpreted as small particles of material having a size between around 1 micron and 250 microns.
  • solid parts as used in the specification and claims refers to materials of a specific fixed shape having at least one dimension greater than around 1000 microns.
  • Workpieces can be either solid parts or powders. When the workpiece is a solid part, the powder which is selected for the workpiece to be placed amongst is generally inert to the process and its functions comprise heat transfer, scrubbing and intermixing. When the workpiece is powder, the powder still fulfills the functions of heat transfer, mixing and scrubbing but is also the object of treatment.
  • Treatments are carried out in a retort, mounted for rotation about a generally horizontal axis.
  • the retort may be heated or cooled by gases transported to the interior of the retort through a fluid passage and an axle on which the retort is mounted for rotation about a longitudinal axis.
  • the retort is preferably supported on a tilt frame to permit the retort to tilt in a vertical plane about a horizontal axis so that particulate material in the retort may flow by gravity into and out of a desired end of the retort upon tilting of the retort to a predetermined tilt angle.
  • the enclosed retort is sealed from atmosphere and mounted on a pair of aligned end axles for rotation.
  • Flow lines or flow passages into and out of the retort are provided through the axles. Gases and particulate material may be injected into the retort and exhausted form the retort as desired while the retort is rotating. Solid parts may be placed within the retort amongst the powders or may be loose amongst the powders or may be fixtured to rotate with the retort.
  • Flow conduits including filters are provided in one end axle to inject gases into the retort and exhaust gases form the retort.
  • the flow of the gases through the conduits may be reversed and this is effective for minimizing any clogging of the filters.
  • the particulate material or powder is injected through a conduit in the other aligned end axle.
  • a vacuum is normally used for the exhaust of particulate material from the retort.
  • Valve means for the conduits effectively control the flow of gas and particulate material into and out of the retort through the conduits in the axially aligned end axles.
  • Each conduit includes a fixed conduit portion connected to a swivel for the rotating axle and a rotatable conduit portion extending through the axle and communicating with the interior of the retort.
  • a detachable container for particulate material may be mounted on an end axle to supply particulate material to the retort.
  • the detachable container which is not normally mounted for rotation with the axle may be removed after injection of particulate material within the retort and another container connected to the axle to receive particulate material from the retort if desired.
  • the particulate material within the container may be fluidized for ease of movement within the interior of the container.
  • the particulate material injected into the retort from the separate container may be cooled to a predetermined low temperature, prior to injection, if desired, thereby acting to quench hot solid parts placed within the retort.
  • the retort is preferably mounted on a pair of axially aligned end axles, one on each end of the generally cylindrical retort.
  • a gas conduit is positioned in an end axle and a solid particulate conduit is positioned within the other end axle.
  • Valve means for the conduits are mounted for rotation with the axles to control the flow of gas and solid particles within and out of the retort.
  • the present invention provides means for loading and unloading particulate material in a minimum of time while the retort is rotating and with minimal loss of the particulate material.
  • the particulate material may be easily injected during operation of the retort.
  • a sample of the particulate material within the retort may be easily removed during operation of the retort for suitable testing or the like.
  • the process of the present invention is directed to a process for mechanically fluidizing small metallic particles within a retort mounted for rotation about a horizontal axis, and particularly to such an process which includes the isothermal control of an exothermic or endothermic reaction of the small metal particles with another material injected into the rotatable retort.
  • An endothermic reaction is a process or change that takes place with the absorption of heat whereas an exothermic reaction is a process or change that takes place with the creation or evolution of heat. It is desired that such an endothermic or exothermic reaction be controlled under a uniform or constant temperature, (i.e. an isothermal control).
  • the temperature of the reaction can be controlled by adding or removing heat as necessary during rotation of the retort.
  • a precise isothermal control may be maintained during the exothermic or endothermic reaction.
  • the material injected into the retort during rotation may comprise a particulate material and the rate of injection for particulate material also controls the rate of reaction between the injected particulate material and the initial particulate material already in the retort.
  • a mechanically fluidized retort provides the heat transfer, intimacy and residency with little gas flow because the fluidization does not require the passage of gas through the material. Fluidization is mechanical so the gas may stay in residence within the fluidized mass long enough for the desired reactions to take place. The fluidization action results in near constant movement of particles relative to each other so they do not stick together even at relatively high temperatures. Nevertheless, the heat transfer rate in a mechanically fluidized device is sufficient to control the temperature of the reaction by adding or removing heat as necessary.
  • the injection of material into the retort, particularly particulate material, during rotation of the retort and fluidizing of particulate material within the retort, is at a predetermined controlled rate to control the rate of reaction between the particulate material within the retort and the material being added to the retort.
  • the present invention provides an unexpected capability to maintain a precise isothermal condition for exothermic and endothermic reactions.
  • the process and apparatus may be utilized for the treatment of various small metallic particles.
  • aluminum particles may be utilized to coat small nickel particles or powders.
  • Another example is in the reduction of the oxygen content and carbon content of small iron particles.
  • Fig. 1 is an isometric exterior view of the apparatus comprising the present invention and showing a retort mounted for rotation and for tilting;
  • Fig. 1 A is a view of the apparatus of Figure 1 with certain parts cut away to show internal components.
  • Fig. 1B is an enlarged section of the area indicated as 21 in Fig. 1A.
  • Fig. 2A shows the apparatus in position to receive powder from an adjacent removable container connected to an end axle.
  • Fig. 2B shows the apparatus of Figure 1 in normal operating position.
  • Fig. 2C shows the apparatus in a position to discharge powder into a receiving container detachably connected to an end axle.
  • Fig. 3 is an orthographic section at a vertical plane through the rotating axis of the apparatus.
  • Fig. 4 is an orthographic section at a horizontal plane through the rotating axis of the apparatus.
  • Fig. 5 is an enlarged section of the area indicated as 65 in Fig. 3.
  • Fig. 6 is an enlarged section of the area indicated as 69 in Fig. 4.
  • Fig. 7 is an enlarged section of the area indicated as 63 in Fig. 3.
  • Fig. 8 is an enlarged section of the area indicated as 61 in Fig. 3.
  • Fig 8A is an alternate view of the area shown in Fig. 8 in which a component has been removed and set aside for clarity.
  • Fig. 9 is an orthographic section of an area shown as 67 in Fig. 4.
  • Fig.10 is an isometric section of a removable injection device for injecting additional particulate material into the retort.
  • Fig. 11 is an isometric section of a removable sampling device for taking samples from the retort.
  • Fig. 1 shows an exterior view of the machine assembly generally indicated as 1.
  • Support frame 3 rests on the floor and provides a static support base for all components.
  • Tilt gear motor 9 mounts to support frame 3 and controls the tilting of tilt frame 5 with respect to support frame 3.
  • Mounted on the tilt frame 5 is heater assembly 14 which is fastened semi-permanently to tilt frame 5.
  • Supply piping 11 feeds gas to and from the commutator 13.
  • Supply piping 11 and the exterior of commutator 13 are free to tilt with tilt frame 5.
  • Gear motor 7 is also fastened to tilt frame 5 and provides rotational force for axle 18.
  • Axle 18 rotates inside heater assembly 14.
  • Mounted to rotate with axle 18 are reversing valve 17, filter 15, and the interior portion of commutator 13.
  • Fig 1 A is an enlarged view of machine 1 and is partially cutaway to show internal components.
  • Drive sheave 23 is mounted to axle 18 and provides force from gear motor 7 through drive belt 25.
  • Heater elements 27 are mounted within heater assembly 14 and connected to each other through connector 29. Connector 29 may also be attached to an exterior electrical supply source not shown.
  • the retort is shown generally as 31 and contains powder 33, cooling coil 35, and filter elements 37.
  • Axle 18 rotates on two sets of bearings indicated generally as 39.
  • Axle 18 is permanently welded to retort 31.
  • Tilt frame 5 comprises upper frame 5A and lower frame 5B.
  • Retort 31 comprises vertical endwall 31 A, cylindrical section 31 B and tapered endwall 31 C.
  • Heater assembly 14 comprises endwall 14A, cylindrical section 14B, second endwall 14C and interior insulation 14D.
  • Fig. 1 B shows a close-up of the section indicated as 21 on Fig. 1A.
  • second axle 41 rotates on bearing set 39 and is welded to endwall 31 C.
  • valve member 43 which reciprocates inside second axle 41 and is biased to close upon endwall 31 C by spring 45.
  • Spring 45 bears on enlarged section 47 of valve member 43.
  • Closure 49 is mounted releasably to second axle 41.
  • Closure 49 has a removable plug 51 which in turn connects to valve 53 mounted thereto, which communicates to conduit 55 which extends the length of valve member 43 to offer a small entrance conduit to the interior of retort 31 by opening valve 53.
  • Removable plug 51 with valve 53 may be removed.
  • FIGs. 2A, 2B and 2C show machine 1 respectively in positions for receiving powders, normal operations, and unloading powders.
  • exterior vessel 62 comprises gas entrance nozzle 62A, fluidizing plenum 62B, connector 62C, all permanently connected to exterior wall 62D. Powder loaded into exterior vessel 62 is removably attached to an end axle of machine 1 by connection 62C. When tilt frame 5 is tilted approximately 30 degrees as shown, powder flows through connector 62C into the interior of the machine.
  • FIG. 2B the machine has rotated tilt frame 5 to the horizontal position for normal operations with exterior vessel 62 removed from connector 62C.
  • FIG. 2C tilt frame 5 has been further rotated.
  • a separate exterior vessel 64 is removably attached to the end axle by connector 62C so that powder exits from machine 1 into exterior vessel 64.
  • Vessels 62 and 64 along with connector 62C do not normally rotate with the end axle 41. However, under some situations, it may be desirable for vessels 62, 64 and connector 62C to rotate with the end axle 41.
  • powders are loaded into the retort, normally when it is in the position of Fig. 2A. Powders can also be blown into the retort when it is horizontal, as in Fig. 2B, since the retort is generally filled only a little more than half full. Powders are unloaded when the retort is positioned as in Fig. 2C.
  • Machine 1 may be positioned as shown in Fig. 2C so that hot powder, which has previously been used to heat components 31 P and 31 C may be dumped directly into exterior vessel 64.
  • the hot parts 31 P mounted on fixtures 31 Q will remain in the machine.
  • the machine can be raised to the position shown in Figure 2A and cold powders may be injected into the machine, from exterior container 62. This will cause a very substantial effect upon solid parts 31 P mounted within the machine as shown in Figure 4.
  • retort 31 can be seen to comprise endwall 31 A welded to axle 18. Cylindrical section 31 B is bolted to endwall 31 A by bolts 31 D. Tapered endwall 31 C is welded to cylindrical section 31 B and also to second axle 41. Also welded to endwall 31 A is cooling tube 31 E. Within retort 31 are metal filters 37 which connect to conduits 18A and 18B within axle 18. Conduits 18A and 18B connect respectively with removable conduits 18C and 18D which connect with reversing valve 17.
  • Filter 15 comprises filter insert 15A, filter cap 15B and filter bowl 15C.
  • Filter cap 15B and reversing valve 17 are connected to commutator 13 by bolts 16. Gas flow from commutator 13 passes to reversing valve 17 through conduit 19 which contains valve 19A.
  • Retort 31 , axle 18 and second axle 41 rest as a unit and are rotated by gear motor 7 through reduction unit 7A and drive sheave 7B in bearing sets 39 and 39A.
  • Bearing sets 39 and 39A are identical having radial slots 39B and 39C.
  • Bearing set 39 is retained by holders 40A and 40B which are welded respectively to tilt frame 5A and 5B. Likewise holders 40C and 40D are respectively welded to tilt frames 5A and 5B.
  • Holders 40A and 40B have inwardly extending ribs 40E which engage slot 39B to hold bearing set 39 from moving longitudinally.
  • Holders 40C and 40D are not equipped with ribs to engage slot 39C and thus bearing set 39A may move longitudinally with respect to holders 40C and 40D to allow for differences in expansion and contraction of retort 31 , axle 18 and second axle 41 with respect to tilt frame 5.
  • Circled areas 65, 63 and 61 respectively are shown in detail on Figs. 5, 7 and 8.
  • Gas and water lines 71 A, 71 C, 71 E and 71 G supply gas or water to and from commutator 13.
  • Gas enters through line 71 A with valve 71 B providing a source of control.
  • Gas is exhausted through line 71 C with valve 71 D providing control.
  • Cooling water enters through line 71 E and is exhausted through line 71 G.
  • Water is supplied to line 71 E through a piping shown in schematic form generally as 80. Cooling fluids are drawn through the system by vacuum pump 81 through line 80A which connects to line 71 G to the commutator 13.
  • Supply of cooling water is by line 80C through valve 80F to line 80B and thence to line 71 E.
  • Air can enter the system at line 80D and is controlled by valve 80E.
  • valve 80F is initially closed so that only air is drawn through line 80D and controlled by valve 80E. This provides air cooling to minimize the shock on the cooling system within the retort. After a period of time, valve 80F may be opened and valve 80E may be closed to introduce water into the cooling system. Cooling fluids exit the retort through line 73 equipped with shut off valve 73A and connect to conduit 18E and axle 18 subsequently connecting to cooling tube 31 E described in Figs. 3 and 4.
  • Fig. 4 includes circled areas 69 and 67, which are described later respectively in Fig. 6 and 9.
  • workpieces 31 P may be mounted on fixtures 31 Q within retort 31 as shown in Figure 4.
  • the principal purpose of the fine powder within the retort is to transfer heat uniformly from the walls of retort 31 into workpieces 31 P or to allow heat to flow rapidly from parts 31 P through the powder and into the retort 31.
  • Fig. 5 shows a close up of the area detailed within the circle as 65 in Fig. 3. It shows the details of reversing valve 17.
  • Reversing valve 17 is designed so that gas entering line 19 may be alternately directed to conduits 18A or 18B in axle 18 to provide a reversal of flow through filters 37 shown in Fig. 7. Since filters 37 are in a dusty atmosphere, it is desirable not to have the direction of flow constantly the same, but should be periodically reversed so the filter is flushed of any contaminate that might penetrate it.
  • Incoming gas from line 19 enters reversing valve 17 and alternately is directed to connectors 18C or 18D which connect respectively with conduits 18A and 18B and axle 18.
  • Reversing valve 17 as shown in Fig.
  • valve body 17A comprises piston 17C, bushing 17B, valve body 17A, inlet 17L, ports 17G and 17J, and lower plug 17D.
  • valve piston 17C When valve piston 17C is in its upmost position as shown, gas from line 19 passes through inlet 17L into chamber 17H, then through port 17E through conduit 17F into chamber 17K, thence out port 17G through connector 18D into conduit 18B.
  • piston 17C When piston 17C is lowered to its lower position, gas coming through line 19 enters through inlet 17L into chamber 17H which by the position of piston 17C then allows the gas to flow to port 17J into connector 18C and thence into conduit 18A. Irrespective of the position of piston 17C, gas exhausting from either conduit 18A or 18B passes out port 17M into port 15E of filter cap 15B.
  • Fig. 6 is the area designated 69 in Fig 4 and shows details of commutator
  • Commutator 13 is designed to change all incoming gas and electric lines from static positions in relation to tilt frame 5 to rotational movement in relation to tilt frame 5.
  • Commutator 13 comprises housing 13A, rotor 13G, having numerous ports thereto, one being shown as 13H which connects with outlet port 13J.
  • Bearings 13E and 13F allow rotor 13G to rotate in a fixed relationship with housing 13A.
  • Electric commutator 13D is also mounted in receptacle 13K of rotor 13G.
  • Electrical connection 13L connects to electric commutator 13D. Connection 13L is stationery and electric commutator 13D is fixed in cavity 13K in rotor 13G and rotates with rotor 13G.
  • Inlet gas is supplied through line 71 A through a shut off valve 71 J into ports between two seals 13C, passes into rotor 13G through ports not shown and exits through a connection shown as line 19 in Fig. 5. Exhaust comes out of filter section 15B through port 13P into a port not shown through rotor 13G, thence between seals 13C into line 71 C.
  • Inlet cooling fluids enter line 71 E which is passed between seals 13C into internal ports not shown and exit at connection 13L through line 73 and valve 73A.
  • Spent cooling water passes through valve 74A through line 74 into connection 13N into rotor 13G through ports not shown and exits between seals 13C into line 71 G.
  • a valve and piping manifold indicated as 13B is connected to incoming gas through a line not shown which tees into the incoming line at tee 71 K.
  • Valve and piping manifold 13B individually directs gas between seals 13C. If any of the seals 13C should have a leak, the leak would be gas coming from manifold 13B rather than the exterior air.
  • the pressure applied through the manifold 13B is the same as the supply pressure entering the commutator through line 71 A.
  • valve 71 J it is possible to raise the supply of pressure at manifold 13B above that in the commutator 13. In an extreme case, valve 71 J may be closed entirely and vacuum be drawn through line 71 C.
  • Manifold 13B will pressure seals 13C to assure the seals are pressure activated and if any leak does occur inward leak is preferred gas in manifold 13B rather than atmospheric gas.
  • FIG. 7 is an enlarged view of circled area 63 on Fig. 3, shown are the endwall 31 A of retort 31 with cooling coils 31 E.
  • a portion of axle 18 is shown with internal conduits 18A and 18B.
  • the end of conduits 18A and 18B are filter assembly 37.
  • Each filter assembly 37 consists of permeable metal membrane cylinder 37A and end washer 37B and bolt 37C.
  • Bolt 37C engages in threaded engagement with threads 37D in the end of conduits 18A and 18B.
  • Bolt 37C has a cross hole 37F and a longitudinal hole 37E which allows communication of gas through the permeable membrane 37A, through cross hole 37F, through longitudinal hole 37E and into conduits 18A and 18B.
  • Second axle 41 is mounted on bearing set 39. Mounted within second axle 41 is valve member 43. Mounted on the end of second axle 41 is closure member 49 which has valve 53 mounted integrally thereto. Valve 53 communicates with a conduit through valve member 43 shown as 55. By opening valve 53 it is possible to gain entrance through end member 49 through valve member 43 into the interior of the retort 31 for purpose of injecting material or taking samples.
  • Spring 45 biases valve member 43 towards the seated position. Spring member 45 seats against surface 41 A and second axle 41 and seats against ring 47 which is mounted by ribs 47A to valve member 43.
  • Fig. 9 is the enlarged section 67 shown on Fig. 4 .
  • the purpose is to show how liquid enters through the axle and into cooling coils along endwall 31 A.
  • the end of axle 18 is shown rotated into a position so that conduits 18E and 18F lie in a cross section view.
  • Cooling fluid enters conduit 18E, passes through connection tube 31 F into cooling coil 31 E. Fluid is circulated through cooling coil 31 E in a spiral fashion.
  • Coil 31 E is welded permanently to wall 31 A. After the fluid reaches the outermost portion, it returns through 31 G into conduit 18F.
  • Injector assembly 90 comprises body section 91 A having end wall 91 B, piston 911, with chamber 91 K therebetween. Solid materials can be placed in chamber 91 K. By pushing forward on piston 911, particulate material can be forced against endwall 91 B and thence through valve 92A and connection 92B.
  • Piston 911 is made of a permeable material. Piston 911 is bolted to rod 91 D and is fixed on rod 91 D through spacer 91 N and bolt 91 H. Spacer 91 J is positioned by anti-rotation member 91 E and bolt 91 H.
  • Bushing 91 G provides means for rod 91 D to pass through bushing 91 G.
  • Conduit 92E brings supply gas through valve 92D into chamber 91 M formed between piston 911 and fixed end bushing 91 J.
  • Valve 92C is allowed to bleed off supply gas and thereby control pressure in chamber 91 M.
  • Yoke assembly 91 L provides a means of holding bushing 91 G so that rod 91 D may pass therethrough.
  • Anti-rotation assembly 91 E is rectangular in shape to fit within the rectangular confines of yoke 91 L so that rod 91 D will not rotate. This allows one to apply threads to rod 91 D if desired to help push it forward against materials in cavity 91 K and force material therefrom through valve 92A into conduit 92B and into the machine.
  • conduit 92E into chamber 91 M In normal operation gas entering conduit 92E into chamber 91 M also passes through permeable piston 911 and partially fluidizes material within cavity 91 K. This gas pressure therefore applies force to push piston 911 against a material within cavity 91 K, but also allows some gas to fluidize that material, and make it more amenable to flow into conduit 92B.
  • injector assembly 90 In operation, injector assembly 90 would be attached to valve 53 in Fig. 3 so that material could be injected into retort 31. Conduit 92B is designed to allow rotation so that injector 90 can be a static position even though valve 53 and axle 41 were rotating.
  • Sampling assembly 95 comprises body 96A, having end bushing 96B and second end bushing 96D, forming a chamber 96G therebetween. Surrounding chamber 96G is permeable sleeve 96F. Operation rod 96E can pass slideably through end bushing 96D through urging of handle 96J. Gas entering port 96C in through bushing 96B into chamber 96G can pass through permeable sleeve 96F into line 97 which is controlled by valve 97A and bypass valve 97B. In operation, the sampling assembly is attached to valve 53 in Fig. 3.
  • valves 97A and 97B By manipulating valves 97A and 97B it is possible to first pressurize the entire assembly to equal that within the retort. It is then possible to use handle 96J to push rod 96E through connection 96C into conduit 55 to clear it of any foreign material. Interior retort 31 may also be pressurized from gas through line 97. Then after rod 96E is returned to the position shown in Fig. 11 , gas may be exhausted through valve 97B and material from the interior retort 31 will flow through conduit 55 though valve 53 into sample assembly 95 and collect in chamber 96G.
  • the operations which can be performed by the apparatus as described herein include: (I) loading the retort; (2) normal operation under desired conditions of pressure, vacuum, and heating or cooling; (3) unloading the retort; (4) obtaining samples from within the retort; (5) reversing of flow of gases through the filters within the retort; (6) assuring uniform gas mixture throughout very large retorts; (7) injecting additional materials into the retort; and (8) quenching objects within the retort by unloading hot powder and reloading cold powder.
  • retort 31 Materials may be injected into the interior of retort 31 by the method indicated in Fig. 2A. Tilt frame 5 with all appurtenances attached thereto is tilted upward about 30 degrees. Endcap 49 is removed per Fig. 8 and container or vessel 62 is attached in its place. Container 62 presses inwardly against rib 47A of valve member 47, depressing spring 45 and creating a gap between valve member 43 and retort endwall 31 C whereby material from container 62 flows through the center of second axle 41 into retort 31.
  • fluidizing membrane in plenum assembly 62B comprises the lower slope of vessel 62 so that gas may be injected through pipe 62A into plenum 62B through a suitable membrane to fluidize the powder material in vessel 62 so that it flows readily.
  • Figs. 1 and 1 A show machine 1 in normal operation position.
  • powders 33 partially fills the interior of retort 31.
  • Powders 33 within retort 31 become agitated as retort 31 is rotated on axle 18.
  • Powders 33 in the upper portion of retort 31 will be less dense than those in the lower portion and in any one revolution of retort 31 all of the powders undergo substantial movement. Referring to Figs.
  • Heat elements 27 may then be exhausted to the atmosphere or may pass into a vacuum pump or in some cases may be directed into a chemical deactivation unit.
  • Electrical power is supplied through heater elements 27 through connection 29.
  • the high temperature of heater elements 27 radiates heat to the exterior of retort 31 wherein heat is transferred through the walls of retort 31 into the powders 33 which contact the interior surface of retort 31.
  • Insulation 14D prevents substantial heat loss to the surrounding area.
  • Walls 14A, 14B and 14C contain the insulation 14D and heater elements 27 into a contiguous unit.
  • the heater assembly 14 is split along a horizontal axis with each half bolting to tilt frame 5, as indicated in Figs. 1 and 1 A.
  • Gear motor 7 supplies rotating power through belt drive 25 through driven sheave 23 which is attached to axle 18 and causes it to rotate which in turn rotates retort 31 and second axle 41 and all other parts attached thereto.
  • cooling fluids are supplied through line 71 E through commutator 13, thence through line 73 through conduit 18E.
  • Two embodiments for cooling are shown.
  • a cooling tube 35 is attached to the ends of conduits 18E and 18F and cooling fluid circulates through tube 35 creating a flow of heat from powders 33 through the walls of the tube 35 to fluids within the tube 35.
  • Figs. 3 through 9 show a different style of cooling unit in which cooling coil 31 E is welded to the back of retort wall 31 A.
  • cooling fluids from line 18E pass into the cooling coil 31 E and spiral outward along the face of retort wall 31 A returning through conduit 31 G and connecting with conduit 18F which then returns fluid through line 74 into rotor 13G of commutator 13, and thence returns fluid to the external system through line 71G.
  • Fig. 7 it is seen that filters 37 are constantly exposed to the fine powders 33 within retort 31. Gas entering through conduit 18A or 18B passing through one of the filter units 37 tends to force powders away from membrane 37A of filter unit 37, but in the other membrane 37A, powders are drawn into the pores of the membrane 37A. If operations are continued, the membrane 37A through which the gas is returning may eventually become clogged with particles. To avoid this it is desired to reverse the filters 37 from time to time so that the filter first functioning as an gas inlet filter functions as a gas exhaust filter and vice versa. This function is provided by valve 17 shown in detail on Fig. 5. Referring to Fig. 5, gas flow entering line 19 passes through port 17L into chamber 17H.
  • valve 17C When the unit is in the uppermost position, gas passes from chamber 17H through port 17E through line 17F in piston 17C and thence through line 17G eventually through line 18B into the retort 31. Returning gas exits through line 18A through couplers 18C and is directed to port 17J, thence through the interior of valve body 17A exiting through port 17M into port 15E in filter unit 15.
  • valve piston 17C When valve piston 17C is moved downward input gas enters through port 17L into chamber 17H and then passes directly into port 17J entering the retort through line 18A and gas exits through conduit 18B through line 17G.
  • the final exhaust port within valve 17 is port 17M and the inlet port is always 17L but by the position of valve piston 17C the gas flowing into the axle will flow alternately through port 17J or port 17G.
  • valve member 71 D shown in Fig. 4 may be operated from full on to full off on a timed basis, with valve 71 D being primarily in the off position. Whenever valve 71 D is in the off position, gas may enter the retort 31 but will tend to build pressure in the retort 31. Since there is no tendency for the gas to flow directly out the adjacent filter, it will penetrate uniformly through all powders 33 in retort 31.
  • valve 71 D From time to time, when valve 71 D is opened to exhaust all the gas from the interior of retort 31 A, an event that will take place quite suddenly, especially if a vacuum pump not shown is attached at valve 71 D. By operating in this manner it is assured that gas entering through one of filters 37 will thoroughly mix with the interior of a retort of any size before being exhausted through the adjacent filter.
  • valve 53 shown in Figs. 8 and 8A the injection unit shown in Fig. 10 is attached to valve 53 shown in Figs. 8 and 8A.
  • Materials to be injected are placed in chamber 91 K.
  • Gas pressure is then introduced into line 92E controlled through valve 92D to create pressure in chamber 91 M.
  • Gas in this area then passes through the permeable walls of piston 911 to fluidize the particles within chamber 91 K.
  • Combination of gas pressure within chamber 91 M and physical pushing on rod 91 D forces material in chamber 91 K to pass through valve 92A through conduit 92B into valve 53 thence through conduit 55 in the interior of valve number 43 and into the interior of retort 31.
  • Valve 92C offers a means of further controlling pressure in chamber 91 M and also for releasing gas from chamber 91 M when it is desired to retract piston 911 such as to allow more material to be loaded in chamber 91 K.
  • a sampling unit generally shown as 95 in Fig. 11 is used.
  • Connection 96C is attached to valve 53 in a manner similar to that used to attach the injection unit 90.
  • Valves 97A and 97B are manipulated, first to equalize the pressure so that sampling unit 95 may be safely attached, then to reduce the pressure within chamber 96G so that material may flow from the interior of retort 31 , through conduit 55 through valve 53 thence through connection 96C into the chamber 96G. Gases from the interior of retort 31 are present with the solid particulate materials.
  • Rod 96E is slideably connected to the interior of bushing 96D so that rod 96E may be extended through port 96C through valve 53 and thence through conduit 55 to clear any materials which may be lodged within conduit 55. Rod 96E is long enough to extend to the interior of retort 31.
  • Fig. 2C shows a method for unloading the machine after treatment.
  • Tilt frame 5 and all appurtenances attached thereto are tilted to near vertical position.
  • receiving unit 64 Prior to tilting, receiving unit 64 is attached in place of end cap 49.
  • Receiving unit 64 depresses valve member 43 compressing spring 45 thus creating a gap between valve member 43 and sloping wall 31 C.
  • powder material flows from the interior of the retort aided by sloping walls 31 C into the interior of container 64.
  • retort 31 it is desired to change the interior temperature of retort 31 with great speed.
  • the unit may be operated in the position shown in Fig. 2B for a desired period of time while powders are heated to a temperature which may be as high as 1000C and is at least about 750C.
  • An insulated container 64 similar to 62 may then be attached to the unit and the unit depressed to position shown in Fig. 2C and all of the hot powders will exit from retort 31 into container 64C.
  • the solid materials 31 P held by fixtures 31 Q within retort 31 will still, however, be at the elevated temperature.
  • the unit may then be tilted to the position shown in Fig 2A and a second container 64 similar to receiving container 62 attached thereto.
  • the second container will contain powders having a temperature less than about 550C and may be much less or cooled below 0C, and these powders will be suddenly injected into retort 31 while retort 31 A is rotating.
  • the effect will be that components that have previously been heated by powders which were taken out are now subject to the cooling effect of very cold powders. The result being a very substantial thermal quench of such said materials, as may be desirable for certain metallurgical reactions.
  • the amount of powders to be injected may be calculated so as to allow the material to stabilize at a particular temperature which is reached when the heat within the fixtured units is transferred into the powders and an equilibrium temperature is reached. Examples of Uses of Process
  • copper oxide particles were loaded into the retort and temperature was increased to approximately 570 Kelvin with an argon atmosphere contained within the retort.
  • a temperature of 570K was reached, small amounts of hydrogen were mixed with the argon, increasing the amounts until the exothermic reaction created by hydrogen reacting with the copper oxide to produce pure copper and water was matched by the cooling rate of the retort.
  • all heat to the retort was discontinued.
  • the retort was maintained at a constant temperature of 570K merely by controlling the rate of injection by hydrogen which reacted exothermically with the copper oxide forming water and pure copper.
  • the temperature of 675K was maintained for 30 minutes after which a sample of material was extracted by allowing the retort to pressurize to about 10 psig, then opening a small port into the retort allowing the pressure differential to push out a sample. The temperature was then raised in 50 degree increments holding at each temperature increment for about 30 minutes and taking a sample after each hold period. By the time a temperature of 920K had been reached, the samples were found to contain nickel and aluminum which had reacted with each other to form a nickel aluminide. Another example which produced unexpected results was the formation of a thin film of aluminum nitride on small particles of aluminum, ranging in average size from 5 to 20 microns.
  • the aluminum powder was loaded into the retort and heated to 670K under argon atmosphere. The atmosphere was then changed to ammonia and the temperature held for 4 hours. The temperature was then increased over a period of 4 hours to 870K and held for an additional 6 hours. Temperature was then increased to 973K and held for a period of 6 hours. Examination showed only a total nitrogen content of 0.2%. The powder was still free flowing even though held at 973K, which is about 50 degrees above the melting point of aluminum. Analysis later showed the powder within the thin nitride shell did melt at around 920K. The powder was heated to above 1270K and then was cooled again, and the metal again froze when the temperature was cooled below around 91 OK. The nitride shell had sufficient strength and continuity to retain within it the molten aluminum and prevent it from coalescing with adjacent powders.
  • Carbon is frequently used for the partial removal of oxygen from iron powders but seldom is the process complete. The reason lies in the variable presence of oxygen in the iron. If too much carbon were added it would reduce all of the oxygen present and then excess carbon would remain in the iron, possibly carburizing the iron. To avoid this, carbon is generally used for only a partial reduction of the oxygen in water atomized steel powder. Hydrogen is then added to remove the remaining oxygen as water vapor. With the mechanical fluidizing device it is possible to complete the entire reduction with carbon without adding undesirable excess carbon.
  • any carbon added to the metal or mixed with iron in the retort is intimately connected with the oxygen, immediately forming a carbon oxygen compound such as carbon monoxide.
  • the effluent of the retort can be monitored with gas detection equipment. When the temperature is brought to above approximately 920K, carbon in the iron reacts with oxygen until all the carbon is depleted. Until the carbon is depleted, the effluent contains a carbon oxygen compound, mixed with the argon. After all of the iron from within carbon in the iron is depleted, the effluent changes to argon, indicating a completion of the reaction.
  • Additional carbon is then injected into the retort and additional oxygen is removed as a carbon oxygen compound. This process is continued until the addition of small amounts of carbon produces no more oxygen in the effluent. At that point it is known that all of the oxygen has been removed from the iron, yet no significant amount of carbon has been added.
  • a retort was loaded with water atomized steel containing about 2% oxygen in purity.
  • the steel also contained about 0.7 percent carbon.
  • the retort interior was blanketed with argon and heated to 920K for a period of eight hours. Samples were extracted every thirty minutes. Examination of the samples showed constantly decreasing amounts of oxygen until at the end of the test, the oxygen content was less than half the initial amount. Some additional carbon remained but because the temperature was so low, insignificant amounts of this carbon entered the steel.
  • the effluent would have been monitored to determine when oxygen ceased to be extracted. Instead of all the carbon being premixed with the steel, a certain amount of the carbon would be injected into the mixture, with injection ceasing as soon as the effluent indicated a lack of oxygen being removed.
  • Another method of removing carbon and oxygen from iron powder utilizes hydrogen. Iron powder was loaded into the retort and heated under argon to 1120K. Argon was injected into the retort until 1120K was reached after which hydrogen was injected into the retort. Temperature was maintained for three hours. The carbon in the iron diffused to the surface of the powder and reacted with some of the oxygen to form a carbon-oxygen gaseous effluent which was drawn off the retort. After the carbon was removed the hydrogen reacted with the remaining oxygen to form water which was drawn away by vacuum. The vacuum on the conduit leading gas away from the retort prevents the water from condensing in the exit conduit and commutator.
  • Powders were placed in the retort and the retort was purged and then filled with argon to create a perfectly inert mixture into which the tin and carbon could react. Temperature was brought slowly to 450K and held within a temperature of 440K to 450K for a period of several hours. The fine tin powders joined to the surface of the larger carbon particles so that each carbon powder was completely coated in a cocoon of tin. It was found by trial and error that temperatures in excess of 480K resulted in substantial amounts of tin forming into balls rather than attaching to the carbon. Temperatures lower than 400K did not result in substantial coverage of the carbon with tin.
  • a further precaution against agglomeration is the addition of inert spheres of metal or ceramic into the retort amongst the powders to be treated.
  • These additional microspheres must have a rounded or semi-spherical shape and the smallest microsphere must be larger than the largest workpiece powders to allow subsequent separation.
  • Nitrided stainless steel powders are suitable for use with most powder workpieces such as titanium which has a very high affinity for oxygen. For those workpiece powders such as iron which have less affinity for oxygen, zirconia peening shot has proved satisfactory.
  • Semi-spherical powder in the range of 100 to 500 microns has proved useful. Shot as large as 1500 microns has also been used but thermal transfer is somewhat diminished.
  • Powders are often separated from each other through use of screens having carefully made uniform holes of selected sizes. Most powders have a range of particle sizes. Screens are made in standard sizes such as 60, 80, 100, 150, 200, 270 and 325 sizes which refer to the number of holes in a standard section of screen. The workpiece powder must be measured such as by screening to determine the largest particle size. The additional microspheres must then be selected so that the smallest particle therein will not pass through a screen at least one size larger than that which captures the largest particle in the workpiece powder.
  • non-metallic powders such as coating a kaolin workpiece with zirconium oxide, coating a ferrous alloy workpiece with silicon carbide, or coating a nickel alloy workpiece with aluminum oxide, for example.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Manufacturing & Machinery (AREA)
  • General Engineering & Computer Science (AREA)
  • Dispersion Chemistry (AREA)
  • Muffle Furnaces And Rotary Kilns (AREA)

Abstract

La présente invention concerne un appareil (1) et un procédé destinés à traiter une matière particulaire ou une poudre (33) d'un calibre particulaire permettant une fluidification dans une cornue (31) montée rotative sur deux axes (18, 41). Cette cornue (31) est montée sur un cadre basculant (5) assurant un mouvement d'inclinaison dans le plan vertical. Des conduits de gaz (18A,18B) montés dans un axe (18) assurent l'admission et l'échappement du gaz de la cornue (31). Un conduit (55) monté dans l'autre axe (41) permet l'introduction de la matière particulaire dans la cornue (31) ou son extraction, comme décrit à la Fig. 1B. Un ensemble d'injection amovible (90, Fig. 10) permet d'injecter la matière particulaire additionnelle. Un ensemble à prélèvement amovible (95, Fig. 11) permet de prélever dans la cornue (31) un échantillon de la matière particulaire. La rotation de la cornue (31) entretient un brassage continu des particules de matière particulaire entre elles et avec les parois de la cornue rotative (31).
PCT/US1998/011053 1998-05-29 1998-05-29 Appareil et procede destines a traiter une matiere particulaire dans une cornue rotative WO2000028098A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/US1998/011053 WO2000028098A1 (fr) 1998-05-29 1998-05-29 Appareil et procede destines a traiter une matiere particulaire dans une cornue rotative
EP98926136A EP1095166A1 (fr) 1998-05-29 1998-05-29 Appareil et procede destines a traiter une matiere particulaire dans une cornue rotative

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1998/011053 WO2000028098A1 (fr) 1998-05-29 1998-05-29 Appareil et procede destines a traiter une matiere particulaire dans une cornue rotative

Publications (1)

Publication Number Publication Date
WO2000028098A1 true WO2000028098A1 (fr) 2000-05-18

Family

ID=22267174

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1998/011053 WO2000028098A1 (fr) 1998-05-29 1998-05-29 Appareil et procede destines a traiter une matiere particulaire dans une cornue rotative

Country Status (2)

Country Link
EP (1) EP1095166A1 (fr)
WO (1) WO2000028098A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11497618B2 (en) 2006-12-07 2022-11-15 DePuy Synthes Products, Inc. Intervertebral implant

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5303904A (en) * 1990-01-18 1994-04-19 Fike Corporation Method and apparatus for controlling heat transfer between a container and workpieces
US5324009A (en) * 1990-01-18 1994-06-28 Willard E. Kemp Apparatus for surface hardening of refractory metal workpieces
US5407498A (en) * 1990-01-18 1995-04-18 Kemp Development Corporation Mechanically fluidized retort and method for treating particles therein

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5303904A (en) * 1990-01-18 1994-04-19 Fike Corporation Method and apparatus for controlling heat transfer between a container and workpieces
US5324009A (en) * 1990-01-18 1994-06-28 Willard E. Kemp Apparatus for surface hardening of refractory metal workpieces
US5407498A (en) * 1990-01-18 1995-04-18 Kemp Development Corporation Mechanically fluidized retort and method for treating particles therein

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11497618B2 (en) 2006-12-07 2022-11-15 DePuy Synthes Products, Inc. Intervertebral implant

Also Published As

Publication number Publication date
EP1095166A1 (fr) 2001-05-02

Similar Documents

Publication Publication Date Title
US6251337B1 (en) Apparatus and method for treating a particulate material within a rotating retort
US5958156A (en) Process for treating a particulate material within a rotating retort
EP0605444B1 (fr) Procede et appareil destines a durcir la surface de pieces en materiau refractaire
CA1272077A (fr) Chargement en dur pour metaux de lit fluidise
US4693863A (en) Process and apparatus to simultaneously consolidate and reduce metal powders
US5766544A (en) Process for fluidizing particulate material within a rotatable retort
EP1441039A2 (fr) Procédé de préparation d'un article avec matrice renforcée par dispersion
JPH05228363A (ja) セラミック又はサーメット粉末物質の製造装置及び方法
US5324009A (en) Apparatus for surface hardening of refractory metal workpieces
US5759483A (en) Apparatus for treating a particulate material within a rotating retort
EP1095166A1 (fr) Appareil et procede destines a traiter une matiere particulaire dans une cornue rotative
US5303904A (en) Method and apparatus for controlling heat transfer between a container and workpieces
US4478871A (en) Method for hardfacing a ferrous base material
FR2777688A1 (fr) Poudres d'alliage d'uranium et procede de fabrication de combustible nucleaire a l'aide de telles poudres
ZA200306174B (en) A method for performing thermal reactions between reactants and a furnace for same.
US5407498A (en) Mechanically fluidized retort and method for treating particles therein
EP0355207B1 (fr) Procédé d'activation de particules susceptibles de former des hydrures métalliques
JPS59208046A (ja) 粒子分散型複合材料の製造方法
JPH0195286A (ja) 熱間静水圧加圧装置
WO2003076105A1 (fr) Generateur de particules fines, dispositif de coulage et procede de coulage
Yasue et al. Elemental blended powders semisolid forming of Ti-Al based alloys
JPS59107990A (ja) 炭素を含む材料の炭化物被覆方法
Sohn et al. Self-propagating high temperature synthesis (SHS) of intermetallic compounds titanium and nickel aluminides
RU2082559C1 (ru) Способ получения титано-никелевого сплава, близкого к эквиатомному составу
RU2120840C1 (ru) Способ приготовления шихты для твердых сплавов на основе карбида вольфрама

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): BR CA CN JP RU

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 1998926136

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1998926136

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1998926136

Country of ref document: EP