US3874844A - Tunnel kiln - Google Patents

Tunnel kiln Download PDF

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Publication number
US3874844A
US3874844A US380289A US38028973A US3874844A US 3874844 A US3874844 A US 3874844A US 380289 A US380289 A US 380289A US 38028973 A US38028973 A US 38028973A US 3874844 A US3874844 A US 3874844A
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Prior art keywords
tunnel kiln
kiln
firing
burners
tunnel
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Expired - Lifetime
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US380289A
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English (en)
Inventor
Heinz Behrens
Paul Schneider
Ernst Zapf
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    • 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
    • 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
    • F27B9/26—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 on or in trucks, sleds, or containers
    • F27B9/262—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 on or in trucks, sleds, or containers on or in trucks
    • F27B2009/266—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 on or in trucks, sleds, or containers on or in trucks the truck having conducts for guiding the oven atmosphere
    • 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
    • F27B2009/3623—Heaters located under the track

Definitions

  • ABSTRACT The specification describes a tunnel kiln adapted to be heated with gaseous etc. liquid fuel, in the case of which the fuel is supplied to at least one horizontally arranged pair of burners, which are directed from the lateral limits of the tunnel kiln and in its lower part towards each other and burn in separating channels underneath the stacking surface of kiln in vehicles adapted to pass through the tunnel kiln.
  • the burners directed towards each other of some pairs of burners are offset along the direction of travel of the firing vehicle in the tunnel kiln channel by a distance which is equal to at least the thickness of the partition between the firing channels and is at the most equal to the clearance firing channel width.
  • the invention relates to a tunnel kiln, more particularly for the ceramic industry, adapted to be heated with gaseous, atomized or gasified liquid fuel, in the case of which the fuel is supplied to at least one horizontally arranged pair of burners, which are directed from the lateral limits of the tunnel kiln and in its lower part towards each other and burn in separating channels underneath the stacking surface of kiln vehicles adapted to pass through the tunnel kiln,
  • Ceramic firing kilns have for example volumes of up to several hundred cubic meters and in the case of tunnel surfaces or kilns there may be clearance widths of 6 meters and more.
  • the firing temperature in the case of such kilns lies at l,250C for example and a discrepancy in the firing temperature of EA: Sc (Seger cone) can be permitted.
  • EA: Sc Green cone
  • the permissible temperature departure or discrepancy at every position of the kiln or kiln cross-section in the case of tunnel kilns thus lies in the order or magnitude of ilOC, a requirement which to date has not been properly fulfilled.
  • burners have already been developed, whose particular characteristic resides in that they operate with relatively high feed pressures both of the gas and also of the combustion air so that very high feed speeds result.
  • pulsed burners are used, in the case of which there is practically no atomization.
  • These pulsed burners have a preestablished length of trajectory, which may if necessary be adjusted, the power of the burner not being determined by changing the length of the trajectory, but by the number of the particles propelled along this trajectory per unit time, or by increasing or reducing the quantity of oil injected per pulse by suitable change in the times of opening of the burner nozzle.
  • the length of trajectory which as far as possible should extend over the whole breadth, for example, of one tunnel kiln.
  • a further method for heating firing spaces with gaseous, atomized or gasified liquid fuels have been proposed in which it is possible to bring about such an equalization of the temperature that the requirements existing today in the case of the firing of ceramic material can be fulfilled in an optimum manner.
  • This method resides in that the power of the one burner of a pair of burners is periodically and uninterruptedly varied from a minimum to a maximum and back again and simultaneously the power of the other burner of the pair of burners is so regulated between a maximum and a minimum that the fuel gases come up against each other, the sum of the powers of both burners of SUMMARY OF INVENTION
  • One aim of the invention is that of creating a tunnel kiln in which, while still making use of this principle of firing, the use of regulated burners which are matched in a paired fashion as regards regulation can be eliminated without any substantial effect on the results of this principle of firing.
  • the invention consists in a tunnel kiln adapted to be heated with gaseous, atomized or gasified liquid fuel, in the case of which the fuel is supplied to at least one horizontally arranged pair of burners, which are directed from the lateral limits of the tunnel kiln and in its lower part towards each other and burn in separating channels underneath the stacking surface of kiln vehicles adapted to pass through the tunnel kiln, characterised in that the burners directed towards each other of some pairs of burners are offset along the direction of travel of the firing vehicle in-the tunnel kiln channel by a distance which is equal to at least the thickness of the partition between the firing channels and is at the most equal to the clearance firing channel width.
  • the arrangement is such that the partitions are rounded off or blunted at their ends adjacent to the tunnel kiln channel side walls.
  • the partition walls preferably have openings in the direction of travel, or on a build up of individual bricks arranged with a spacing between them.
  • FIG. 1 shows a side view, drawn partly in section, of a tunnel kiln, in which the principle of the invention is employed and in which, furthermore, for shortening the length of the figure sections of the tunnel kiln not necessary for explaining the principle of the invention are omitted.
  • FIG. 2 shows a plan view, partly shown in section, of the tunnel kiln in accordance with the representation in accordance with FIG. 1.
  • FIG. 3 shows an enlarged horizontal section through the part shown in section in FIG. 2.
  • FIG. 4 shows a position, in accordance with FIG.2,
  • FIG. 5 depicts an alternate embodiment of the present invention and further illustrates a further positioning of the partitions employed in the practice of the present invention as related to thepositioningof the burners.
  • FIG. 6 shows the part X in FIG. 3
  • the tunnel kiln in accordance with FIGS. and 2 is of conventional construction apart from the particular arrangement of the burners;
  • the firing vehicles or on an enlarged trucks 3 at the inlet end 4 of the kiln run on rails 2 ashamed ing through the tunnel kiln 1 into the latter.
  • the vehicles are driven into the kiln by means of an advancing system which does not form part of the present inven tion and is therefore not shown.
  • the firing vehicles 3 run on pairs of wheels 5, 6 and on their respective base I plate 7 carry a system made up of partitions 8.'
  • the material 10 to be tired is stacked and can, for example, be ceramic drainage pipes, sanitary ware, porcelain ware, etc. Since the particular type of the material 10 to be tired is not of significance forthe principle of the invention, the material or charge, 10 to be fired is only shown as a block and not shown in detail.
  • the firing vehicles in the tunnel kiln 1 pass through a preheating zone, a firing zone and the cooling zone. i
  • the burners 12 are arranged in niches or openings 14 in the side walls 15 of the tunnel kiln 1, whose kiln channel-16 is closed at the top by upper masonry 17. Below the rails 2 there is generally an access passage or channel 18. At 19 the firing vehicles leave the cooling zone of the tunnel kiln 1.
  • Reference numeral 20 denotes the lateral limiting walls of i the tunnel kiln in which the niches or openings 14 are provided for receiving the burners 12, 12a.
  • the flames of the two burners l2 and 12a (see FIG. 4) of the corresponding pair of burners are temporarily separated by the partitions 8 between two firing channels 13.
  • the burners can therefore so. burn that their flames extend to their full length.
  • annular eddies formed rise at the tunnel kiln wall opposite to the burner and at the tunnel kiln wall adjacent to the burner descend so that two oppositely directed adjacent annular eddies are formed which occupy the whole breadth of the kiln.
  • the desired equalization of j the atmosphere is thus achieved, owing to the fact that the annular eddies change over from a shape, which occupies half the breadth of the tunnel kiln, into a shape which occupies the whole of the tunnel kiln breadth so that the above-mentioned prior art principle is carried out in two stages instead of continuously.
  • the partitions can be made blunted or rounded at their two ends in order to facilitate the flowin of the gas currents as the partitions are moved past the burners. Such a blunting is clearly shown in FIG. 6 at 21.
  • the firing channels 13 or passages are open at the top so that the firing or combustion gases can pass through openings into the actual firing space 16. Furthermore, the partitions 8 between the firing channels 13 can be provided with openings 22 without this involving any change in the basic principle of the invention. Such openings are shown in FIG. 5 in a clear manner.
  • a tunnel kiln of the type having a firing channel and adapted to be heated with gaseous, atomized or gasified liquid fuel and which directly contacts the ware disposed on the stacking surface of a movable kiln vehicle which passes therethrough, and wherein the fuel is supplied to at least one horizontally arranged pair of burners disposed in the lower part of the kiln and which extends from the lateral limits of the tunnel kiln towards each other, each pair of burners burning in firing channels defined by partitions disposed underneath the stacking surface of the kiln vehicle as the vehicle passes through the firing zone in the tunnel kiln, the improvement which comprises: the at least one horizontally arranged pair of burners are offset, with respect to each other, along the direction of travel of the kiln vehicle in the tunnel kiln, by a distance equal to at least the thickness of the partition between the firing channels and at most equal tothe clearance firing channel width.
  • a tunnel kiln in accordance with claim 1 characterized in that the partitions are blunted or rounded off at their ends adjacent to the tunnel kiln channel side walls.
  • a tunnel kiln in accordance with claim 1 characterized in that the vehicles of the tunnel kiln are arranged to pass constantly through the kiln except for vehicle change-over during the course of feed.
  • a tunnel kiln in accordance with claim 1 characterized in that the partitions have openings in the direction of travel.
  • a tunnel kiln in accordance with claim 1 characterized in that the partitions are made up of individual bricks arranged with a spacing.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Tunnel Furnaces (AREA)
  • Furnace Details (AREA)
US380289A 1972-07-24 1973-07-18 Tunnel kiln Expired - Lifetime US3874844A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2236231A DE2236231A1 (de) 1972-07-24 1972-07-24 Mit gasfoermigen oder zerstaeubten fluessigen oder vergasten brennstoffen beheizter tunnelofen, insbesondere fuer die keramische industrie

Publications (1)

Publication Number Publication Date
US3874844A true US3874844A (en) 1975-04-01

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US380289A Expired - Lifetime US3874844A (en) 1972-07-24 1973-07-18 Tunnel kiln

Country Status (5)

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US (1) US3874844A (ro)
DE (1) DE2236231A1 (ro)
FR (1) FR2194301A5 (ro)
GB (1) GB1400134A (ro)
RO (1) RO60288A (ro)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4412814A (en) * 1981-12-21 1983-11-01 Dennis Jr Silas P Apparatus and method for operating a brick kiln
US20180258506A1 (en) * 2015-09-18 2018-09-13 Schwartz Gmbh Heat treatment system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3222871C2 (de) * 1982-06-18 1984-10-04 FHW-Brenntechnik GmbH, 8267 Neumarkt-St Veit Vorrichtung zum Brennen von Grobkeramik in einem Tunnelofen, insbesondere von Ziegeln

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1965832A (en) * 1931-05-21 1934-07-10 Harrop Ceramic Service Company Tunnel kiln
US2867431A (en) * 1955-07-01 1959-01-06 Selas Corp Of America Metal heating
US3129933A (en) * 1959-07-23 1964-04-21 Cremer Gottfried Tunnel furnace arrangement
US3158364A (en) * 1960-07-05 1964-11-24 Cremer Gottfried Method of heating tunnel kilns and a tunnel kiln for carrying the method into effect
US3279774A (en) * 1963-05-29 1966-10-18 Nikex Nehezipari Kulkere Annealing furnace
US3485900A (en) * 1967-02-08 1969-12-23 Fetok Gmbh Kiln operation
US3584849A (en) * 1968-07-24 1971-06-15 Gottfried Cremer Equipment for firing ceramic and other kilns or furnaces

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1965832A (en) * 1931-05-21 1934-07-10 Harrop Ceramic Service Company Tunnel kiln
US2867431A (en) * 1955-07-01 1959-01-06 Selas Corp Of America Metal heating
US3129933A (en) * 1959-07-23 1964-04-21 Cremer Gottfried Tunnel furnace arrangement
US3158364A (en) * 1960-07-05 1964-11-24 Cremer Gottfried Method of heating tunnel kilns and a tunnel kiln for carrying the method into effect
US3279774A (en) * 1963-05-29 1966-10-18 Nikex Nehezipari Kulkere Annealing furnace
US3485900A (en) * 1967-02-08 1969-12-23 Fetok Gmbh Kiln operation
US3584849A (en) * 1968-07-24 1971-06-15 Gottfried Cremer Equipment for firing ceramic and other kilns or furnaces

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4412814A (en) * 1981-12-21 1983-11-01 Dennis Jr Silas P Apparatus and method for operating a brick kiln
US20180258506A1 (en) * 2015-09-18 2018-09-13 Schwartz Gmbh Heat treatment system

Also Published As

Publication number Publication date
DE2236231A1 (de) 1974-02-14
RO60288A (ro) 1976-06-15
GB1400134A (en) 1975-07-16
FR2194301A5 (ro) 1974-02-22

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