US3726515A - Industrial oven and method of operating the same - Google Patents

Industrial oven and method of operating the same Download PDF

Info

Publication number
US3726515A
US3726515A US00118812A US3726515DA US3726515A US 3726515 A US3726515 A US 3726515A US 00118812 A US00118812 A US 00118812A US 3726515D A US3726515D A US 3726515DA US 3726515 A US3726515 A US 3726515A
Authority
US
United States
Prior art keywords
burners
chamber
group
combustion gases
oven
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
US00118812A
Other languages
English (en)
Inventor
R Knaak
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.)
Koppers Wistra Ofenbau GmbH
Original Assignee
Koppers Wistra Ofenbau GmbH
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 Koppers Wistra Ofenbau GmbH filed Critical Koppers Wistra Ofenbau GmbH
Application granted granted Critical
Publication of US3726515A publication Critical patent/US3726515A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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 peculiar to furnaces of these types
    • F27B9/36—Arrangements of heating devices
    • 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
    • C21D1/52—Methods of heating with flames
    • 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
    • F27B9/30—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
    • 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
    • F27D7/00—Forming, maintaining, or circulating atmospheres in heating chambers

Definitions

  • Ovens are known for heating and heat-treating of metallic or other workpieces. Generally speaking, it is perhaps the primary consideration of such ovens that the workpieces are heated as evenly as possible. This is particularly important in order to obtain uniform material characteristics in the workpieces after heat treatment and annealing processes. Another reason for this requirement is to obtain uniform characteristics of material behavior during subsequent heat-deformation that is when the material is subsequently formed in heated conditionand also for limiting the development of heat tensions in these materials or workpieces.
  • the requirement for temperature uniformity is not very strict, it is sufficient to provide in the oven walls a large number of burners which are then individually adjusted depending on the local heat requirements.
  • the thermal lift of the hotter burner gases becomes quite noticeable, meaning that the hot combustion gases have a tendency to move upwardly along the walls and to collect at the underside of the oven roof. This means that the oven obviously becomes hotter in the upper regions than in the lower regions so that this solution is usually not suitable where the requirements for evenness of temperature are strict.
  • the high-speed combustion gases which travel relatively far into the interior of the oven chamber should not directly impinge upon the workpieces to be heated, and for this reason it is preferred to so arrange the high-speed burners that their stream of combustion gases upon injection into the chamber moves along one of the walls bounding the latter. It is quite customary to provide in the side walls of such ovens a row of burners each, whose streams of combustion gases are so oriented as to move horizontally and with low distance above the hearth of the oven. It must be kept in mind that in such constructions the workpieces to be treated must not interfere with the development of the streams of combustion gases. Therefore, particularly if the workpieces are of large dimensions or elongated, they must be positioned at adequately large spacing from the hearth by utilizing supports which afford this spacing.
  • the burners are also arranged in banks adjacent the hearth in such a manner that the stream of combustion gases moves vertically upwardly along the side walls.
  • the impulse or pulse of the stream of combustion gases decreases correspondingly.
  • the equalizing effect of the high-speed burners becomes the less effective, the more the burner is throttled.
  • the temperature regulation is effected not by throttling the burners, but by switching them on and off as required.
  • the burners may be so arranged that their streams of combustion gases are directed more or less towards one another. However, they may also be offset so that the stream of combustion gases from one burner is directed towards a gap between the streams of combustion gases from two oppositely located burners.
  • the admixture and agitation of the combustion gases, and particularly the rolling or turning over in the chamber of the oven can be improved substantially in that the burners are so arranged that the impulse of the respective streams of combustion gases causes a rotation effect of the combustion gases in the chamber, leading to the development of the coiled rotating flow of'the combustion gases.
  • this approach is omitted in actual practice for certain reasons to specific applications, for instance in so-called shaft furnaces in which an elongated substantially cylindrical workpiece is arranged in upright position and located in a similarly cylindrical oven housing. This makes possible a good and adequate flow of combustion gases about the workpiece with complete symmetry of heating.
  • the oven is not sufficiently symmetrical, nor are the workpieces arranged sufficiently symmetrically within the oven, to permit the utilization of this approach where a single rotating coil of combustion gases is created.
  • the differing quality in the aligning of hearth and oven walls, and also the arrangement of the workpieces of the hearth necessitates the lack of sym' metry which cannot be overcome even if the workpieces are not located directly upon the hearth but instead are spaced from it by suitable supports.
  • a concomitant object of the invention is to provide a method of operating such an oven.
  • one feature of the invention resides, in an industrial oven, in the combination of wall means defining an internal chamber, a first group of burners and a second group of burners.
  • the first group of burners is provided in the wall means and operative for injecting into the chamber combustion gases which form a first helix of combustion gases which fills the chamber and which rotates in one direction about its longitudinal axis.
  • the second group of burners are also provided in the wall means but are operative for injecting into the chamber combustion gases which form a second helix of combustion gases which also fills the chamber but rotates in an opposite direction about its longitudinal axis.
  • FIG. 1 is a somewhat diagrammatic transverse sectional elevation of one embodiment of the invention
  • FIG. 2 illustrates the embodiment of FIG. 1 during a different operating stage
  • FIG. 3 is a view similar to FIG. 1 but illustrating a further embodiment of the invention.
  • FIG. 4 illustrates the embodiment of FIG. 3 in a different stage of operation
  • FIG. 5 is also a view similar to FIG. 1 but illustrating still another embodiment of the invention.
  • FIG. 6 illustrates the embodiment of FIG. 5 in a different stage of operation.
  • reference numeral 1 identifies the wall means or housing of the oven which defines within it the oven chamber.
  • the reference numeral 2 identifies a hearth carriage with the wheels 3 provided thereon, and on the carriage 3 there is supported a workpiece (here illustrated in cylindrical configuration) which is supported on the hearth carriage via supports 5.
  • the illustrated oven has a first or left group of burners 6 and a second or right group of burners 7.
  • the oven In longitudinal direction in which the hearth carriage 3 can move, that is normal to the plane of the drawing, the oven may have any desired length and may be subdivided into separate zones for temperature-regulating purposes.
  • the arrows indicate that the left-hand burner group is operating, with all burners operating together and injecting into the interior of the oven chamber a stream of combustion gases which forms in the chamber a helix of combustion gases elongated longitudinally of the oven 1 and rotating in counterclockwise direction.
  • the helix rotates about and surrounds the workpiece 4 and fills or substantially fills the interior space of the oven.
  • FIG. 2 shows that the other or righthand burner group is operating, causing a similar helix of rotating combustion gases but which, as indicated by the arrows in FIG. 2, rotates in clockwise direction counter to the direction of rotation of the helix in FIG. 1.
  • the burners are high-speed burners of known construction which are of such type that the combustion gases leave the burner at a speed of better than 50 m/sec. Also, it is preferable that the regulating of ternperatureswhen it is no longer necessary for the burners to operate continuouslybe carried out not by throttling of the burners but instead by switching them on and off as required to obtain the desired temperature regulation. This avoids the problem which has been discussed earlier herein.
  • the burners'in the left-hand group 8 operate to produce the helix of combustion gases which rotates in counterclockwise direction.
  • the burners 9 of the righthand bank are also in operation and facilitate and add to the formation and rotation in counterclockwise direction of the illustrated helix of combustion gases.
  • FIGS. 5 and'6, finally, show still a further embodiment.
  • the oven in these Figures is basically the same as in FIGS. 1 and 2 and need not be further described.
  • the workpieces are of different configuration from FIGS. 1, 2 and 3, 4 but this also is of no importance.
  • the workpieces of FIGS. 1 and 3 could similarly be treated in the oven of FIG. 5.
  • FIGS. 5 and 6 What is different in terms of the present invention in the embodiment of FIGS. 5 and 6 over the preceding embodiments is the fact that here there are provided not only all of the burners in the embodiments of FIGS. 3 and 4 but additional burner groups similar to the burner groups 6 and 7 of FIG. 1, and the burner group 8 of FIG. 3; but arranged below the roof or ceiling of the oven.
  • These burner groups which have reference numeral 8a in FIG. 5, cooperate with the other burners of the other groups to produce the clockwise or counterclockwise rotating helices.
  • the left-hand burner group 8 is operating, together with the righthand bank of burners 9, and with the right-hand burner group 8a.
  • FIG. 6 it is the right-hand burner group 8 which operates, together with the left-hand bank of burners 9, and the left-hand burner group 8a, to produce the clockwise rotating helix of combustion gases.
  • the invention provides according to a further embodiment that the selection of the burner groups in all regulating zones which operate at any one time is controlled by a control device, such as a timer switch, so that during a predetermined time interval always'the groups of all zones are operated which willproduce a helix rotating in either the clockwise direction or in counterclockwise direction. Subsequently, when the time interval has passed, the remaining burner groups are switched on to produce a helix which operates in the opposite direction to that prevailing before.
  • a control device such as a timer switch
  • the heat requirements will vary during operation in wide latitudes, per time unit. For instance during the start-up a high amount of heat energy is usually required, whereas during the subsequent maintenance and equalization only a substantially smaller amount of heat energy is needed.
  • the invention has a final concept which provides that if the oven requires at any given time a high amount of heat energy, all burner groups are operated simultaneously, but that when the oven has a small or smaller heat requirement, the burner groups are so operated as to obtain the helices which rotate alternately in clockwise and in counterclockwise direction.
  • wall means defining an internal'chamberya first group of burners provided in said wall means and operable for injecting into said chamber combustion gases forming a first helix which fills said chamber and rotates in one direction about workpieces located in said chamber; and a second group of burners provided in said wall means and operable in alternation with said first group for injecting into said chamber combustion gases forming a second helix which fills said chamber and rotates in an opposite direction about the workpieces located in said chamber.
  • burners are high-speed burners injecting said combustion gases at speeds in excess of 50 m/sec.
  • control means operatively associated with said burners for alternately operating said burners of said first group, and said burners of said second group.
  • control means comprising timer means.
  • wall means defining an internal chamber; a first group of burners provided in said wall means and operative for injecting into said chamber combustion gases forming a first helix which fills said chamber and rotates in onedirection; a second group of burners provided in said wall means and operative for injecting into said chamber combustion gases forming a second helix which fills said chamber and rotates in an opposite direction; and control means operatively associated with said burners for operating the burners of said first and second groups alternately when the heat-energy requirement is relatively low, and for operating said burner of both of said groups simultaneously when the heat-energy requirement is relatively high.
  • a method as defined in claim 6, comprising the step of injecting said combustion gases at speeds in excess of 50 m/sec.
  • step of alternately operating said burners comprises alternately activating and de-activating said burners of said first and second groups.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Tunnel Furnaces (AREA)
  • Muffle Furnaces And Rotary Kilns (AREA)
  • Combustion Of Fluid Fuel (AREA)
US00118812A 1970-03-03 1971-02-25 Industrial oven and method of operating the same Expired - Lifetime US3726515A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19702009761 DE2009761B2 (de) 1970-03-03 1970-03-03 Kammerofen zur waermebehandlung von metallischem gut

Publications (1)

Publication Number Publication Date
US3726515A true US3726515A (en) 1973-04-10

Family

ID=5763830

Family Applications (2)

Application Number Title Priority Date Filing Date
US00118812A Expired - Lifetime US3726515A (en) 1970-03-03 1971-02-25 Industrial oven and method of operating the same
US00335123A Expired - Lifetime US3795478A (en) 1970-03-03 1973-02-23 Method of operation of a chamber furnace

Family Applications After (1)

Application Number Title Priority Date Filing Date
US00335123A Expired - Lifetime US3795478A (en) 1970-03-03 1973-02-23 Method of operation of a chamber furnace

Country Status (5)

Country Link
US (2) US3726515A (pt)
JP (1) JPS4837490B1 (pt)
DE (1) DE2009761B2 (pt)
FR (1) FR2083823A5 (pt)
GB (1) GB1282231A (pt)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3795478A (en) * 1970-03-03 1974-03-05 Koppers Wistra Ofenbau Gmbh Method of operation of a chamber furnace
US3969069A (en) * 1973-04-14 1976-07-13 Koppers-Wistra-Ofenbau Gesellschaft Mit Beschrankter Haftung Burner systems for ovens and methods of operating such systems
US4125364A (en) * 1976-03-22 1978-11-14 Alumax, Inc. High velocity billet heater
US4281984A (en) * 1979-07-18 1981-08-04 Kawasaki Steel Corporation Method of heating a side-burner type heating furnace for slab
FR2486643A1 (fr) * 1980-07-08 1982-01-15 Riedhammer Ludwig Gmbh Four pour la cuisson de pieces ceramiques
US4354827A (en) * 1981-04-17 1982-10-19 Midland-Ross Corporation Process and device for improving heat exchange in furnaces heated by radiant heaters
US5899689A (en) * 1996-10-11 1999-05-04 Demag Italimpianti S.P.A. Furnace for processes and treatments in a sub-stoichiometric atmosphere
US6113386A (en) * 1998-10-09 2000-09-05 North American Manufacturing Company Method and apparatus for uniformly heating a furnace

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4083677A (en) * 1976-09-22 1978-04-11 Bloom Engineering Company, Inc. Method and apparatus for heating a furnace chamber
US4480992A (en) * 1981-10-17 1984-11-06 Sanken Sangyo Kabushiki Kaisha Method of heating a furnace
JPS6097247U (ja) * 1983-12-09 1985-07-02 キンセキ株式会社 圧電振動板の製造装置
CN85102032B (zh) * 1985-04-01 1987-11-11 潘代明 火炕型加热炉及其使用方法
JPH06281364A (ja) * 1993-03-30 1994-10-07 Ngk Insulators Ltd 加熱炉の温度制御方法
JPH1038261A (ja) * 1996-07-18 1998-02-13 Toyota Motor Corp 燃焼装置
FR2761146B1 (fr) * 1997-03-21 1999-05-07 Ind Regionale Batiment Four pour la cuisson d'articles en terre cuite
FR2806097B1 (fr) * 2000-03-08 2002-05-10 Stein Heurtey Perfectionnements apportes au prechauffage de bandes metalliques notamment dans des lignes de galvanisation ou de recuit
DE102016004464A1 (de) 2016-04-15 2017-10-19 Martin-Luther-Universität Halle-Wittenberg Verpackung von Milch in auflösbaren Portionskapseln und Verfahren zu deren Herstellung duch lonen-Hydrokolloid-lnteraktionen
DE102016004463B4 (de) 2016-04-15 2018-03-08 Martin-Luther-Universität Halle-Wittenberg Verpackung von Milch in auflösbaren Portionskapseln und Verfahren zu deren Herstellung durch Kristallisation

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2191438A (en) * 1939-03-21 1940-02-27 Walter R Breeler Furnace
US2492942A (en) * 1949-01-26 1949-12-27 R S Products Corp Roller hearth furnace
US3172647A (en) * 1963-03-26 1965-03-09 Bickley Furnaces Inc Continuous kiln
US3485900A (en) * 1967-02-08 1969-12-23 Fetok Gmbh Kiln operation

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2009761B2 (de) * 1970-03-03 1972-06-08 Koppers-Wistra-Ofenbau GmbH, 4000 Düsseldorf Kammerofen zur waermebehandlung von metallischem gut

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2191438A (en) * 1939-03-21 1940-02-27 Walter R Breeler Furnace
US2492942A (en) * 1949-01-26 1949-12-27 R S Products Corp Roller hearth furnace
US3172647A (en) * 1963-03-26 1965-03-09 Bickley Furnaces Inc Continuous kiln
US3485900A (en) * 1967-02-08 1969-12-23 Fetok Gmbh Kiln operation

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3795478A (en) * 1970-03-03 1974-03-05 Koppers Wistra Ofenbau Gmbh Method of operation of a chamber furnace
US3969069A (en) * 1973-04-14 1976-07-13 Koppers-Wistra-Ofenbau Gesellschaft Mit Beschrankter Haftung Burner systems for ovens and methods of operating such systems
US4125364A (en) * 1976-03-22 1978-11-14 Alumax, Inc. High velocity billet heater
US4281984A (en) * 1979-07-18 1981-08-04 Kawasaki Steel Corporation Method of heating a side-burner type heating furnace for slab
FR2486643A1 (fr) * 1980-07-08 1982-01-15 Riedhammer Ludwig Gmbh Four pour la cuisson de pieces ceramiques
US4368036A (en) * 1980-07-08 1983-01-11 Ludwig Riedhammer Gmbh & Co. Kg Kiln for firing ceramic workpieces
US4354827A (en) * 1981-04-17 1982-10-19 Midland-Ross Corporation Process and device for improving heat exchange in furnaces heated by radiant heaters
US5899689A (en) * 1996-10-11 1999-05-04 Demag Italimpianti S.P.A. Furnace for processes and treatments in a sub-stoichiometric atmosphere
US6113386A (en) * 1998-10-09 2000-09-05 North American Manufacturing Company Method and apparatus for uniformly heating a furnace

Also Published As

Publication number Publication date
US3795478A (en) 1974-03-05
GB1282231A (en) 1972-07-19
JPS4837490B1 (pt) 1973-11-12
DE2009761B2 (de) 1972-06-08
DE2009761A1 (de) 1971-09-30
FR2083823A5 (pt) 1971-12-17

Similar Documents

Publication Publication Date Title
US3726515A (en) Industrial oven and method of operating the same
US4763880A (en) Rotary hearth multi-chamber, multi-purpose furnace system
US4455177A (en) Method and apparatus for chemical heat treatment of steel parts utilizing a continuous electric furnace
US2611790A (en) Electric heat treating furnace
US4148600A (en) Heat treatment furnace for metal strip
JP3086450B1 (ja) 外熱式ロータリーキルン
US3261596A (en) Annealing and decorating lehrs
KR101621047B1 (ko) 코일의 열처리 장치
JP2011007471A (ja) 熱風加熱装置
US2840361A (en) Tunnel furnace for heat treating objects
US2746740A (en) Cycle annealing furnace
US2573019A (en) Strip metal heat-treating
US3556493A (en) Method and apparatus for heat-treating of workpieces
US1916363A (en) Tunnel kiln
US2237966A (en) Heat treating apparatus
CN117210649B (zh) 一种钢材正火设备和钢材正火方法
US2668040A (en) Furnace system
US2991535A (en) Tunnel kiln firing section
US2196321A (en) Regenerative soaking pit furnace
US2127742A (en) Tunnel kiln
JPH05157461A (ja) 加熱炉
JP5384225B2 (ja) 熱風加熱装置
US3672654A (en) Soaking pit furnace
KR20180069321A (ko) 압연설비
JPH05239558A (ja) 移動炉床式連続熱処理装置