GB2146464A - Heating furnace control - Google Patents

Heating furnace control Download PDF

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Publication number
GB2146464A
GB2146464A GB08422586A GB8422586A GB2146464A GB 2146464 A GB2146464 A GB 2146464A GB 08422586 A GB08422586 A GB 08422586A GB 8422586 A GB8422586 A GB 8422586A GB 2146464 A GB2146464 A GB 2146464A
Authority
GB
United Kingdom
Prior art keywords
furnace
temperature
firing
path
length
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.)
Granted
Application number
GB08422586A
Other versions
GB2146464B (en
GB8422586D0 (en
Inventor
Helmuth Klammer
Wolfram Schupe
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.)
Vodafone GmbH
Original Assignee
Mannesmann AG
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 Mannesmann AG filed Critical Mannesmann AG
Publication of GB8422586D0 publication Critical patent/GB8422586D0/en
Publication of GB2146464A publication Critical patent/GB2146464A/en
Application granted granted Critical
Publication of GB2146464B publication Critical patent/GB2146464B/en
Expired legal-status Critical Current

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27BFURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/30Details, accessories or equipment specially adapted for furnaces of these types
    • F27B9/40Arrangements of controlling or monitoring devices
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05DSYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D23/00Control of temperature
    • G05D23/19Control of temperature characterised by the use of electric means
    • G05D23/1927Control of temperature characterised by the use of electric means using a plurality of sensors
    • G05D23/193Control of temperature characterised by the use of electric means using a plurality of sensors sensing the temperaure in different places in thermal relationship with one or more spaces
    • G05D23/1932Control of temperature characterised by the use of electric means using a plurality of sensors sensing the temperaure in different places in thermal relationship with one or more spaces to control the temperature of a plurality of spaces
    • G05D23/1934Control of temperature characterised by the use of electric means using a plurality of sensors sensing the temperaure in different places in thermal relationship with one or more spaces to control the temperature of a plurality of spaces each space being provided with one sensor acting on one or more control means
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27BFURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B9/00Furnaces through which the charge is moved mechanically, e.g. of tunnel type; Similar furnaces in which the charge moves by gravity
    • F27B9/14Furnaces 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
    • F27B9/20Furnaces 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
    • F27B9/22Furnaces 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 rails, e.g. under the action of scrapers or pushers
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27DDETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D19/00Arrangements of controlling devices
    • F27D2019/0006Monitoring the characteristics (composition, quantities, temperature, pressure) of at least one of the gases of the kiln atmosphere and using it as a controlling value
    • F27D2019/0018Monitoring the temperature of the atmosphere of the kiln
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27DDETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D19/00Arrangements of controlling devices
    • F27D2019/0028Regulation
    • F27D2019/0034Regulation through control of a heating quantity such as fuel, oxidant or intensity of current
    • F27D2019/004Fuel quantity
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27FURNACES; KILNS; OVENS; RETORTS
    • F27MINDEXING SCHEME RELATING TO ASPECTS OF THE CHARGES OR FURNACES, KILNS, OVENS OR RETORTS
    • F27M2001/00Composition, conformation or state of the charge
    • F27M2001/15Composition, conformation or state of the charge characterised by the form of the articles
    • F27M2001/1539Metallic articles
    • F27M2001/1547Elongated articles, e.g. beams, rails
    • F27M2001/1552Billets, slabs

Landscapes

  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
  • Control Of Heat Treatment Processes (AREA)
  • Tunnel Furnaces (AREA)

Abstract

The invention relates to a continuous heating furnace control. In order to achieve even heating of material 3 as it passes through the furnace, taking account of irregularities in passage, in material dimensions, and in the hearth lining the furnace is controlled according to the invention by taking over the length of the furnace one or more items of furnace firing data, e.g. temperature as at 10 or fuel and air consumption, progressively converting the measurements taken into signals representative of the temperature change of the pieces of material and the temperature of each piece of heat material located on the length of the furnace as actual temperature. The actual temperature profile so produced is compared with various desired temperatures predetermined locally over the length of the furnace (a reference temperature profile) and in the zones in which a deviation is found, the furnace firing 5, 6 is adjusted to minimize variations therefrom. <IMAGE>

Description

SPECIFICATION Heating furnace control The invention relates to the control of heating furnaces. Particularly, it concerns continuous such control enabling material passing through the furnace to gain heat in accordance with a predeterminable pattern. The invention has especial application in the iron and steel industry.
Controls to date for continuous heating furnaces are designed such that material to be heated runs evenly through the furnace, the hearth of which is evenly lined. When the furnace material has different dimensions and/or gaps are to be found between the individual throughput sections of pieces of material, then the even heating of the material is disturbed. For example, temperature transitions can be detected on the heat material in the vicinity of the gaps. Also, a variable quality of the heat material can cause an uneven heating. Substantial deviations of the heat material temperature also occur if for example, as a result of an interruption in operation in the manufacturing area prior to or following on from the furnace, the speed of passage has to be altered, or if the speed of passage alters several times.
The invention addresses the problem of evenly heating material of material passing through a heating furnace, even at variable throughputs, while also taking account of irregularities in the lining of the furnace hearth. To this end, the invention provides a method of controlling the operation of a heating furnace as material to be heated passes therethrough, comprising the furnace firing over the length of the path of material through the furnace to produce values representative of the temperature of the material and changes therein along said path; comparing such values with a reference temperature profile; and regulating the firing of the furnace as necessary to minimize variations of such values from the reference temperature profile.The monitoring step will normally comprise ascertaining furnace firing data and cyclically converting measurements from such data into said representative values.
The furnace firing may be monitored in the method of the invention by measuring the temperature of the furnace atmosphere along the path of material through the furnace. In an alternative, the quantities of fuel, typically gas, and air consumed can be measured.
Regulation of the furnace firing is preferably accomplished in zones defined along the path of material through the furnace. A typical furnace suitable for control according to the invention has a plurality of burners arranged along the path. At least one, preferably at least two, burners on either side of the path may be used to define each such zone.
The direct measurement of the temperature of the heat material in a furnace is not normally possible, particularly in the iron and steel industry. In a method of the invention several measured values are determined cyclically several times over the length length of the furnace, which values are able to continuously specify the temperature increase of individual pieces of material in the heating path.
The mathematical methods of calculation for this are known. They derive from Fourier's differential equation, which is able to be solved at least iteratively for the conditions of a particular industrial furnace with the aid of electronic data processing machines. Thus for each cycle values are ascertainable for the temperature increase, and through accumulation of the values for each piece of material from the input into the furnace data regarding its representative temperature (actual temperature) and position in the furnace (control zone) can be obtained.
According to the invention, the actual temperature of the heat material determined according to the above technique is compared with a desired temperature profile, which defines in each case predetermined temperatures locally over the furnace length. On the basis of the difference between desired and actual values and as a function of the extent of this difference, the furnace is regulated in zones. Of course, if the control zone is longer than the individual piece of heat material, the furnace is not controlled for each piece individually,but rather only in zones.
The present invention is found to effectively achieve even heating of material passing unevenly through a furnace as well as accommodating a variably dense hearth lining. The firing of the furnace can be adapted independently, according to the throughput speed, and/or according to the dimensions of the material or pieces thereof passing therethrough. The invention enables a higher degree of efficiency than previously possible to be achieved in terms of heating technique and as a consequence, a substantial saving in energy. Further, the savings in energy consumption fully justify the expenditure for the control mechanism.
An embodiment of the invention is now described by way of example and with reference to the accompanying drawing which shows diagrammatically, a side view of a continuous heating furnace adapted for control according to the invention.
The thickly drawn line 1 represents the fireproof casing of the furnace chamber with the inlet 2 and the outlet 4 for material 3 to be heated. The furnace is equipped in each case with a row of burners 5 in the upper furnace and burners 6 in the lower furnace. Each pair of burners 5 in the upper furnace and burners 6 in the lower furnace define a regulating zone. The furnace shown has six regulating zones. The burners 5, 6 supply the furnace with combustible gas and air. The flow of exhaust gas runs contrary to the transportation of heat material to the exhaust outlet at 7.
The material 3 to be treated enters through the inlet 2 into the furnace. The material 3, contrary to the drawing, lies compactly in the furnace and is thus transported by means of a slab pusher 8 on the hearth 9 through the furnace to the outlet 4.
The furnace is equipped with a sensor 10 for the temperature measurement of the furnace atmos phere in each regulating section. In the embodiment shown, a sensor is available for each regulating zone in both the lower and upper furnaces. The drawing also shows a calculator or computer 11, a temperature recording line 12, a burner control line 13 and a line 14 for the transfer to the calculator 11 of data concerning the material 3 and the throughput speed thereof.
The computer 11 is programmed with reference temperature profiles for certain materials, throughput speeds, etc. In response to signals received along lines 12, 14 it adjusts the operation of the burners 5, 6 along lines 13 to maintain the actual temperature profile of material 3 in the furnace to a desired shape, and thus achieves the desired heating level for material passing through the furnace.

Claims (10)

1. A method of controlling the operation of a heating furnace as material to be heated passes therethrough, comprising monitoring the furnace firing over the length of the path of material through the furnace to produce values representative of the temperature of the material and changes therein along said path; comparing such values with a reference temperature profile; and regulating the firing of the furnace as necessary to minimize variations of such values from the reference temperature profile.
2. A method according to Claim wherein the monitoring step comprises ascertaining furnace firing data and cyclically converting measurements from such data into said representative values.
3. A method according to Claim 1 or Claim 2 wherein the regulation of the furnace firing is in zones defined along the path of material through the furnace.
4. A method according to Claim 3 wherein the furnace comprises a plurality of burners arranged along the path of material therethrough, at least one burner on either side of the path defining a said zone.
5. A method according to Claim 4 wherein at least two burners on either side of the path define a said zone.
6. A method according to any preceding claim wherein the furnace firing is monitored by measuring the temperature of the furnace atmosphere along the path of material through the furnace.
7. A method according to any of Claims 1 to 5 wherein the furnace firing is monitored by measuring the quantities of fuel and air consumed along the path of material through the furnace.
8. A method according to any preceding claim wherein material to be heated is passing continuously through the furnace.
9. A method of controlling the operation of a heating furnace substantially as described herein with reference to the accompanying drawing.
10. Continuous heating furnace control wherein several times cyclically over the length of the furnace one or more items of data concerning the furnace firing are ascertained, measured values are progressively converted cyclically into the temperature change of the pieces of heat material and the temperature of each piece of heat material situated on the length of the furnace is determined as the actual temperature, the actual temperature is compared with various desired temperatures preset locally over the length of the furnace and in the zones in which a deviation is found, an alteration to the furnace firing takes place.
GB08422586A 1983-09-09 1984-09-07 Heating furnace control Expired GB2146464B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19833332989 DE3332989A1 (en) 1983-09-09 1983-09-09 CONTINUOUS CONTROL

Publications (3)

Publication Number Publication Date
GB8422586D0 GB8422586D0 (en) 1984-10-10
GB2146464A true GB2146464A (en) 1985-04-17
GB2146464B GB2146464B (en) 1987-01-21

Family

ID=6208938

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08422586A Expired GB2146464B (en) 1983-09-09 1984-09-07 Heating furnace control

Country Status (4)

Country Link
DE (1) DE3332989A1 (en)
FR (1) FR2551849B1 (en)
GB (1) GB2146464B (en)
IT (1) IT1176575B (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4657507A (en) * 1985-02-27 1987-04-14 Kobe Steel, Ltd. Heating control method of heat furnace
US5595481A (en) * 1993-03-30 1997-01-21 Ngk Insulators, Ltd. Temperature control method for heating kiln
EP0755170A3 (en) * 1995-07-17 1997-06-04 Prince Castle Inc Food warmer foil heater and sensor assembly including plural zone heater assembly
EP1146305A1 (en) * 2000-04-11 2001-10-17 Siempelkamp Handling Systeme GmbH & Co. Preheating method with reduction of power during the interruptions of the furnace operation
US7645070B2 (en) * 1997-03-28 2010-01-12 Applied Biosystems, Llc Thermal cycler for PCR

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19506066C2 (en) * 1995-02-22 1997-06-05 Junker Gmbh O Process for operating a heating system for metallic goods
FR2794132B1 (en) * 1999-05-27 2001-08-10 Stein Heurtey IMPROVEMENTS RELATING TO HEATING OVENS OF STEEL PRODUCTS

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1095611A (en) * 1964-02-28 1967-12-20 Bailey Meter Co Improvements in apparatus for regulating heat-treatment furnaces
GB1187639A (en) * 1966-07-25 1970-04-08 Electric Furnace Co Improvements in and relating to a Furnace Heating Control
GB1248006A (en) * 1968-12-21 1971-09-29 Matthias Ludwig Industrieofenb Improvements in or relating to the temperature control of individual furnaces in a furnace installation
GB1258802A (en) * 1968-02-14 1971-12-30
GB1420852A (en) * 1972-08-10 1976-01-14 Lemballage Soc Gen Method of regulating and stabilising the temperature of a fluid flowing from the outlet of a conditioning duct
EP0047682A1 (en) * 1980-08-06 1982-03-17 Saint Gobain Vitrage International Temperature control method and apparatus for a glass sheet in a plural-cell furnace

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3627857A (en) * 1968-02-15 1971-12-14 Yawata Iron & Steel Co Heating controlling system in a multizone type continuously heating furnace
GB1439456A (en) * 1972-06-05 1976-06-16 British Iron Steel Research Method of and apparatus for controlling a furnace
DE2357057B2 (en) * 1973-11-15 1976-12-30 Leisenberg, Manfred, 6312 Laubach METHOD AND DEVICE FOR AIR VOLUME REGULATION IN A TUNNEL FURNACE

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1095611A (en) * 1964-02-28 1967-12-20 Bailey Meter Co Improvements in apparatus for regulating heat-treatment furnaces
GB1187639A (en) * 1966-07-25 1970-04-08 Electric Furnace Co Improvements in and relating to a Furnace Heating Control
GB1258802A (en) * 1968-02-14 1971-12-30
GB1248006A (en) * 1968-12-21 1971-09-29 Matthias Ludwig Industrieofenb Improvements in or relating to the temperature control of individual furnaces in a furnace installation
GB1420852A (en) * 1972-08-10 1976-01-14 Lemballage Soc Gen Method of regulating and stabilising the temperature of a fluid flowing from the outlet of a conditioning duct
EP0047682A1 (en) * 1980-08-06 1982-03-17 Saint Gobain Vitrage International Temperature control method and apparatus for a glass sheet in a plural-cell furnace

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4657507A (en) * 1985-02-27 1987-04-14 Kobe Steel, Ltd. Heating control method of heat furnace
US5595481A (en) * 1993-03-30 1997-01-21 Ngk Insulators, Ltd. Temperature control method for heating kiln
EP0755170A3 (en) * 1995-07-17 1997-06-04 Prince Castle Inc Food warmer foil heater and sensor assembly including plural zone heater assembly
US7645070B2 (en) * 1997-03-28 2010-01-12 Applied Biosystems, Llc Thermal cycler for PCR
US9776187B2 (en) 1997-03-28 2017-10-03 Applied Biosystems, Llc Thermal cycler for PCR
EP1146305A1 (en) * 2000-04-11 2001-10-17 Siempelkamp Handling Systeme GmbH & Co. Preheating method with reduction of power during the interruptions of the furnace operation

Also Published As

Publication number Publication date
FR2551849A1 (en) 1985-03-15
IT1176575B (en) 1987-08-18
DE3332989C2 (en) 1992-10-01
FR2551849B1 (en) 1989-03-17
GB2146464B (en) 1987-01-21
IT8422252A0 (en) 1984-08-07
DE3332989A1 (en) 1985-03-28
GB8422586D0 (en) 1984-10-10

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19940907