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
  • F27B9/30—Details, accessories or equipment specially adapted for furnaces of these types
  • F27B9/36—Arrangements of heating 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
  • F27B13/00—Furnaces with both stationary charge and progression of heating, e.g. of ring type or of the type in which a segmental kiln moves over a stationary charge
  • F27B13/06—Details, accessories or equipment specially adapted for furnaces of this type
  • F27B13/12—Arrangements of heating devices

Definitions

• the invention relates to a method for burning materials containing oxidizable constituents in a furnace, a solid fuel being burned in the furnace.
• Solid fuels of this type are, for example, sawdust, coke breeze or coal dust.
• To fire a furnace with coal dust coal is ground and the coal dust obtained is blown into the combustion chamber and burned.
• An important property of coal dust, which affects the economy of a dust burner system, is the fineness of grinding of the coal dust.
• a high grinding fineness requires high energy costs and leads to high mill wear.
• a coarse grinding leads to the fact that not all of the coal dust is burned, but a portion remains unburned, even if the combustion takes place not with air but with oxygen-enriched air.
• the invention is therefore based on the object of specifying a method of the type described at the outset which enables the production of high quality products when firing materials containing oxidizable constituents.
• This object is achieved in that the unburned fuel occurring in the furnace interior is swirled with an oxygen-containing gas and afterburned.
• this unburned residual material is whirled up and afterburned with the help of an oxygen-containing gas. Since the unburned material usually glows, the afterburning takes place automatically. According to the invention, the oxygen-containing gas can only be directed specifically to the unburned material. Afterburning takes place particularly quickly and completely if the unburned mate rial is whirled up.
• the method according to the invention has decisive advantages over the conventional method.
• the previously occurring temperature difference between the area of the furnace ceiling and the region of the furnace sole is eliminated by the method according to the invention, so that heat is supplied to all fuel at the same temperature level.
• this effect advantageously leads to a temperature increase in the pre-fire zone.
• materials to be burned can be heated up more quickly to the desired temperature level. Since the pre-firing zone is shorter than with conventional methods, the workpieces reach the firing zone more quickly. This advantage can either increase the furnace throughput or improve the quality.
• the process according to the invention results in a uniform temperature distribution over the height of the furnace and an increase in temperature can be achieved in the pre-fire zone, which increases the quality of the fired goods.
• a particularly rapid and effective post-combustion is achieved in a preferred embodiment of the invention when oxygen is used as the oxygen-containing gas.
• the oxygen-containing gas in the form of jets onto the areas on which unburned fuel collects. In this way it is ensured that all unburned components are whirled up and fed to an afterburning.
• clinker or other coarse and fine ceramic material for example, these materials are often treated in a tunnel furnace into which heat can be introduced by burning solid fuels such as coal dust.
• the pottery and ceramics are grouped into stacks that are built on trolleys. The cars are led in a row through the tunnel kiln. As a rule, the stacks on the trolleys are arranged in such a way that the distances between the successive stacks are always constant.
• the pottery or ceramics first pass through a preheating zone in which their organic substances are oxidized. Subsequently, the goods pass through a firing zone, in which the pottery or ceramics reach the highest temperature, and then through a cooling zone.
• the stacks are now fed through the furnace in cycles.
• the stacks are usually positioned after a feed phase and during a break so that there is just a space between two in the firing zone Stacking is located under the ceiling area in which the dust burners are arranged. If, for example, coal dust is now burned, only a part of the coal dust is burned immediately, while a part (as a rule, preferably the dust fraction with a low fineness) remains unburned. This portion of unburned, smoldering coal dust sinks to the bottom of the car, which is not covered by the stacks, and to the earthenware or ceramics to be burned.
• supply devices for oxygen are now arranged, for example, in the ceiling area of the combustion zone in such a way that oxygen which is supplied to these supply devices under pressure, emerges in the form of jets and unburned coal dust is whirled up and afterburned on the soleplate or the material to be burned.
• the oxygen supply devices are arranged in such a way that escaping oxygen does not take part in the combustion taking place at the solid fuel burner.
• the oxygen supply devices can nevertheless be arranged in the area of the burners, but also in the direction of movement of the carriages after this area.
• the application of the method according to the invention to the firing of pottery and ceramics in a tunnel kiln is particularly advantageous.
• the method according to the invention is not restricted to this case. It is also suitable for the production of e.g. Refractory, stoneware, SiC plates and the like.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Tunnel Furnaces (AREA)
• Incineration Of Waste (AREA)
• Furnace Details (AREA)
• Compositions Of Oxide Ceramics (AREA)
• Catalysts (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Biological Depolymerization Polymers (AREA)
• Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6252081

Family Applications (1)

Country Status (4)

Cited By (2)

Family Cites Families (5)

• 1984
  • 1984-12-06 DE DE19843444542 patent/DE3444542A1/de not_active Withdrawn
• 1985
  • 1985-12-02 AT AT85115265T patent/ATE72894T1/de not_active IP Right Cessation
  • 1985-12-02 EP EP85115265A patent/EP0184749B1/fr not_active Expired - Lifetime
  • 1985-12-02 DE DE8585115265T patent/DE3585432D1/de not_active Expired - Fee Related
  • 1985-12-05 ZA ZA859313A patent/ZA859313B/xx unknown

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