US3905759A - Tunnel kiln for heat treatment of cylindrical products - Google Patents

Tunnel kiln for heat treatment of cylindrical products Download PDF

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Publication number
US3905759A
US3905759A US466661A US46666174A US3905759A US 3905759 A US3905759 A US 3905759A US 466661 A US466661 A US 466661A US 46666174 A US46666174 A US 46666174A US 3905759 A US3905759 A US 3905759A
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US
United States
Prior art keywords
kiln
tunnel
tubes
gases
gas
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 - Lifetime
Application number
US466661A
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English (en)
Inventor
Jean Weber
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.)
Ceraver SA
Original Assignee
Ceraver SA
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Filing date
Publication date
Application filed by Ceraver SA filed Critical Ceraver SA
Application granted granted Critical
Publication of US3905759A publication Critical patent/US3905759A/en
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Classifications

    • 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
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/04—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity adapted for treating the charge in vacuum or special atmosphere
    • F27B9/045—Furnaces with controlled atmosphere
    • F27B9/047—Furnaces with controlled atmosphere the atmosphere consisting of protective gases
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/64—Burning or sintering processes
    • 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
    • C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
    • C21D1/767—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material with forced gas circulation; Reheating thereof
    • 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
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/14—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment
    • F27B9/20—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace
    • F27B9/22—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace on rails, e.g. under the action of scrapers or pushers
    • F27B9/227—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity characterised by the path of the charge during treatment; characterised by the means by which the charge is moved during treatment the charge moving in a substantially straight path tunnel furnace on rails, e.g. under the action of scrapers or pushers with rotation of the charge
    • 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
    • F27D5/00—Supports, screens, or the like for the charge within the furnace
    • F27D5/0068—Containers
    • 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
    • F27B9/00—Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/30—Details, accessories, or equipment peculiar to furnaces of these types
    • F27B9/3005—Details, accessories, or equipment peculiar to furnaces of these types arrangements for circulating gases
    • F27B9/3011—Details, accessories, or equipment peculiar to furnaces of these types arrangements for circulating gases arrangements for circulating gases transversally
    • F27B2009/3016—Details, accessories, or equipment peculiar to furnaces of these types arrangements for circulating gases arrangements for circulating gases transversally with arrangements to circulate gases through the charge
    • 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
    • F27D2003/0085—Movement of the container or support of the charge in the furnace or in the charging facilities
    • F27D2003/0097—Advancement along an axis perpendicular to the axis of the workpiece
    • 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
    • F27D99/00—Subject matter not provided for in other groups of this subclass
    • F27D99/0073—Seals
    • F27D2099/0078—Means to minimize the leakage of the furnace atmosphere during charging or discharging
    • F27D2099/008—Using an air-lock

Definitions

  • the present invention concerns a tunnel kiln for heat treatment in a controlledatmosphere with recirculating of gas, for cylindrical products arranged inside support tubes comprising means for moving forward the support tubes in the kiln perpendicularly to their longitudinal axis.
  • the tunnel kiln according to the invention is characterized in that it comprises, moreover, means for sucking the gases from the atmosphere of the kiln by several openings on a longitudinal side of the latter and for dis charging the said gases into the kiln on the opposite longitudinal side thereof by several openings so as to make them flow in a preferential way in the support tubes.
  • the means for discharging the gases of the atmosphere of the kiln into the latter comprise at least a longitudinal lateral chamber parallel to the axis of the kiln and a partition separating that chamber from the kiln, drilled with openings at the level of the cylindrical products subjected to the heat treatment.
  • the partition separating the chamber from the furnace comprises several contiguous mobile elements perpendicular to the hearth of the kiln and parallel to its axis, resting, by a support, in a longitudinal groove in the hearth, drilled with openings at the level of and opposite the cylindrical products and provided with means for driving support tubes for the products;
  • the discharging means for the gases of the atmosphere of the kiln into the latter comprise a series of contiguous distance pieces or spacer assemblies borne by the tubes or arranged between the axles of the drums, spaced apart from the lateral walls of the kiln and provided with openings for the circulating of gases.
  • the chamber is preferably connected to a circuit swept by an inert gas.
  • FIG. 1 is a diagrammatic section of a gase flow device making the gaseous exchanges between the atmosphere of the kiln and the products to be treated easier.
  • FIGS. 2 and 3 are a front view and a profile view of an element forming a spacer arrow by constituting the mobile wall of a chamber for the gas flow.
  • FIG. 4 is an end view of element forming a spacer assembly constituting, by juxtaposition with contiguous elements a mobile wall of a chamber for the circulating of gas, in a kiln in which the products are arranged in support tubes rolling on the hearth.
  • FIGS. 5 to 8 show elevation views and plane views of the elements forming a distance-piece constituting, by juxtaposition with contiguous elements, a mobile wall of a chamber for the circulating of gas, ina kiln in which the products are arranged in support tubes grouped in drums.
  • FIG. 9 is a partial end view of a device for purifying gases of the atmosphere of the kiln which are circulating.
  • a flow of gases is caused inside the support tubes 1, 2, arranged in two layers on the hearth 3 of the kiln, the tubes of the lower layer being separated from one another by distancepieces or spacer assemblies 4 sliding in grooves of the hearth.
  • suction is effected in a duct 10 by a fan 11 and discharge is effected by a duct 12, on the recirculated gases in a zone of the kiln into a longitudinal lateral chamber 13. That chamber is limited on one side by a wall 14 provided with a series of elongated slots 15, situated in a plane, parallel to the hearth, extending through the support tubes of each layer.
  • the chamber 13 may be formed by a continuous series of elements 20 also fulfilling the function of a dis tance-piece or spacer assembly (FIGS. 2 and 3) instead of by a fixed wall such as that in FIG. 1.
  • These elements comprise a stand 21 on which is arranged a hub 22 drilled with elongated holes 15, situated in the diametrical plane of the support tubes of each layer and provided with a rib 23 fonning a cleat. These elements move in a groove 25 formed in the hearth 3.
  • FIG. 4 shows a distance-piece or spacer assembly 30, provided with a recess 31, arranged on two tubes 1 of a lower layer and a tube 2 of an upper layer and providing a lateral opening 32 for the passing of the circulating gases.
  • FIGS. '5 and; 6 show a distance-piece or spacer assembly arrangedbetween the axles 51 of the roller sprocketsSZ on the ramp 53 of two adjacent drums 54.
  • the distance piece 55 drilled with a great number of openings 56 adjacent to the drums, is provided with a hole 57 in which the axles 58 providedwith roller sprockets 59 rotate.
  • FIGS. 7 and 8 show a distance-piece or spacer assembly arranged between, the axles 61 of the roller sprockets 62 on the ramp 63 of two adjacent drums 64.
  • the perforated distance-piece 65 drilled with openings 66 .opposite the drums, is fixed to the flange 28 assembled on the sprockets -67, 68 and supporting the intermediate sprockets 69, 70, 71.
  • a kilnaccording to the invention When a kilnaccording to the invention has to operate in a definite atmosphere, for example, a reducing or inert atmosphere, one may have to recirculate the gases in one or several zones of the kiln (FIG. 9 The gases become progressively charged with condensable vapors which must be removed before they are deposited on the cold parts of the ducts, thereby possibly obstructing them.
  • a hollow cylindrical part 81 cooled by a water flow is installed inside the extraction duct 80, in a somewhere the temperature nonnally pre ventsany condensation.
  • the circulating of the gases is provided by the ventilator 82 and the duct 83 leading to the oppositelateral wall to that containing the extraction duct.
  • the part 81 When the part 81 is charged' with condensate, it is removed into a chamber 84 by means of a rod 85 passing through a packing gland 86, making it pass" rapidly through a fluid-tight valve 87. An inert gas sweeps through the chamber, in the case of the part 81. It is then filled with air, once the part has cooled down, then opened. The part 81 may be removed and replaced by the reverse manoeuvre. A cooling device 88 and a filter 89 may, moreover, be inserted in the gas circuiL. 1
  • ln'a tunnel kiln having an elongated tunnel for heat treatment in a controlled atmosphere with recirculation of gases, of cylindrical products, arranged inside support-tubes and supported thereby, including I means for moving the support tubes in the kiln tunnel perpendicular to their longitudinal axis and along a longitudinal path through said elongated tunnel, the improvement comprising: lateral ducts opening up to respective sides of said tunnel and connected by a gas recirculation duct, means within one of said ducts for sucking gas from one side of said tunnel and discharging gas into said tunnel from the other side thereof, and at least one upright wall member within said tunnel and adjacent the lateral duct discharging re-circulated gas into said kiln with said upright wall member having slots therein at positions corresponding to said tube interiors for causing said re-circulatedgas to flow longitudinally through said tubes and laterally through said kiln as said tubes move longitudinally along a path through said elongated tunnel.
  • a longitudinal lateral chamber extendingparallel tothe axis of the kiln is adjacent the duct discharging the gases into the kiln tunnel, and said wall member comprises partition means separating that chamber from the kiln, with said partition means drilled with openings at the level of the cylindrical products carried by said tube and being subjected to the heat treatment.
  • the partition means separating the chamber from the kiln comprises several contiguous mobile elements extending perpendicular to the hearth of the kiln and parallel to its axis, resting, by a support, in a longitudinal groove in the hearth, said elementsbeing drilled with openings, at the level of and opposite to the cylindrical: products and provided with means for driving the support tubes for the products.
  • the tunnel kiln according to claim 1 further comprising means for separating, from the gases, the condensable vapors, said separating means comprising a cooled removable hollow part and means for extracting said part through a fluid-tight valve in a chamber.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Metallurgy (AREA)
  • Tunnel Furnaces (AREA)
  • Muffle Furnaces And Rotary Kilns (AREA)
  • Furnace Details (AREA)
US466661A 1973-05-08 1974-05-03 Tunnel kiln for heat treatment of cylindrical products Expired - Lifetime US3905759A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7316588A FR2229312A5 (fr) 1973-05-08 1973-05-08

Publications (1)

Publication Number Publication Date
US3905759A true US3905759A (en) 1975-09-16

Family

ID=9118981

Family Applications (1)

Application Number Title Priority Date Filing Date
US466661A Expired - Lifetime US3905759A (en) 1973-05-08 1974-05-03 Tunnel kiln for heat treatment of cylindrical products

Country Status (5)

Country Link
US (1) US3905759A (fr)
JP (1) JPS5053407A (fr)
DE (1) DE2418725A1 (fr)
FR (1) FR2229312A5 (fr)
GB (1) GB1468407A (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US489017A (en) * 1893-01-03 Furnace foe heating steel ingots
US576152A (en) * 1897-02-02 Furnace for heating metal rods
US3620513A (en) * 1968-12-27 1971-11-16 Messer Griesheim Gmbh Method and machine for the rapid heating of tubes

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US489017A (en) * 1893-01-03 Furnace foe heating steel ingots
US576152A (en) * 1897-02-02 Furnace for heating metal rods
US3620513A (en) * 1968-12-27 1971-11-16 Messer Griesheim Gmbh Method and machine for the rapid heating of tubes

Also Published As

Publication number Publication date
DE2418725A1 (de) 1974-11-28
GB1468407A (en) 1977-03-23
FR2229312A5 (fr) 1974-12-06
JPS5053407A (fr) 1975-05-12

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