DE2841626A1 - Soot removal from furnaces used for fully automatic gas carburising - where limited amt. of air is fed into furnace for slow oxidn. of soot deposited on furnace walls - Google Patents
Soot removal from furnaces used for fully automatic gas carburising - where limited amt. of air is fed into furnace for slow oxidn. of soot deposited on furnace wallsInfo
- Publication number
- DE2841626A1 DE2841626A1 DE19782841626 DE2841626A DE2841626A1 DE 2841626 A1 DE2841626 A1 DE 2841626A1 DE 19782841626 DE19782841626 DE 19782841626 DE 2841626 A DE2841626 A DE 2841626A DE 2841626 A1 DE2841626 A1 DE 2841626A1
- Authority
- DE
- Germany
- Prior art keywords
- furnace
- air
- soot
- fed
- fully automatic
- 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
Links
- 239000004071 soot Substances 0.000 title claims abstract description 21
- 238000000034 method Methods 0.000 claims abstract description 18
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 14
- 239000001301 oxygen Substances 0.000 claims abstract description 14
- 239000007789 gas Substances 0.000 claims abstract description 13
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 13
- 239000000523 sample Substances 0.000 claims description 8
- 230000006735 deficit Effects 0.000 claims description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 3
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- GGROONUBGIWGGS-UHFFFAOYSA-N oxygen(2-);zirconium(4+);hydrate Chemical compound O.[O-2].[O-2].[Zr+4] GGROONUBGIWGGS-UHFFFAOYSA-N 0.000 claims description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 abstract 2
- 238000002485 combustion reaction Methods 0.000 description 6
- 238000005255 carburizing Methods 0.000 description 5
- 230000007704 transition Effects 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005256 carbonitriding Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000004817 gas chromatography Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 230000007306 turnover Effects 0.000 description 1
Classifications
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
- C23C8/20—Carburising
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
- Furnace Details (AREA)
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
Abstract
Description
"Verfahren zum Entrußen von Öfen für die vollautoma-"Process for removing soot from furnaces for fully automatic
tische Gasaufkohlung." Die Erfindung betrifft ein Verfahren zum Entrußen von Öfen für die vollautomatische Gasaufkohlung von Werkstücken, wobei bei Temperaturen zwischen 6000 und 9500C, vorzugsweise zwischen 7500 und 8500C Luft in den Ofen geleitet und die im Ofen niedergeschlagene Kohlenstoffschicht weggebrannt wird.table gas carburizing. "The invention relates to a method for debarking of furnaces for the fully automatic gas carburizing of workpieces, whereby at temperatures between 6000 and 9500C, preferably between 7500 and 8500C air is passed into the furnace and the carbon layer deposited in the furnace is burned away.
In allen Anlagen zum Aufkohlen oder Karbonitrieren von Stahl fallen gelegentlich'größere Mengen Ruß an. Da der Ruß sowohl die weitere Aufkohlung beeinträchtigen als auch Schäden an Bauteilen des Ofens hervorrufen kann, sollte er sobald wie möglich ausgebrannt werden. Es ist daher eine häufig geübte Praxis, am Wochenende die Ofentemperatur auf 8500 bis 7500C zu senken, um dann durch die leicht geöffnete Ofentür eine hinreichende Menge Luft in den Ofen eintreten zu lassen. Diese manuell gesteuerte Entrußung hat den Nachteil, daß der Einsatz von Personal erforderlich ist und daß kein objektiver Anhaltspunkt dafür vorliegt, wann die Entrußung abgeschlossen ist. Die manuelle Entrußung ist von der Erfahrung des Bedienungspersonals abhängig.In all systems for carburizing or carbonitriding of steel occasionally large amounts of soot. Because the soot both affect the further carburization as well as damage to components of the furnace, it should be used as soon as possible to be burned out. It is therefore a common practice to keep the oven temperature at the weekend to 8500 to 7500C, and then through the slightly opened oven door a sufficient Letting a lot of air enter the oven. This manually controlled sooting has the disadvantage that the use of personnel is required and that no objective one There is an indication of when the soot will be removed is completed. The manual de-sooting depends on the experience of the operating personnel.
Es ist bereits bekannt, Verbrennungsvorgänge vollautomatisch ablaufen zu lassen, indem die Abgase des Verbrennungsvorgangs analysiert werden. So ist es beispielsweise bekannt, mit Hilfe einer sogenannten X -Sonde den Sauerstoff-Partialdruck in den Auspuffgasen von Verbrennungsmotoren zu bestimmen und anhand des gemessenen Wertes das Mischungsverhältnis von Kraftstoff und Luft so zu regeln, daß sich im Abgas unter allen Betriebszuständen ein konstanter, eine geringe Schadstoffemission garantierender Sauerstoffpartialdruck einstellt.It is already known that combustion processes take place fully automatically by analyzing the exhaust gases from the combustion process. That's the way it is known, for example, with the help of a so-called X probe, the oxygen partial pressure to be determined in the exhaust gases of internal combustion engines and based on the measured Value to regulate the mixing ratio of fuel and air so that the Exhaust gas under all operating conditions a constant, low pollutant emission sets guaranteed oxygen partial pressure.
Lambda-Sonden werden außer zur Steuerung von Brennkraftmaschinen auch zur Steuerung von Feuerungen in Öfen, zur Bestimmung des Sauerstoffgehaltes von Flüssigkeiten und Schmelzen, zur Bestimmung des Sauerstoffgehaltes in der Atemluft von Patienten, zur Steuerung von Aufkohlungsöfen, zur Messung des Sauerstoffpartialdrucks in Vakuum-Anlagen, zur Messung des Sauerstoffpartialdrucks in Schutzgasen, zur Steuerung von Brennöfen in der Keramik-Industrie, in der Gaschromatographie sowie zur Verfolgung von Schwaden- und Wirbelbildung sowie des Gasumsatzes in Öfen, Turbinen und Gastriebwerken eingesetzt. Ein automatisches Verfahren zum Entrußen von Öfen ist jedoch bisher nicht bekanntgeworden.Lambda probes are used to control internal combustion engines as well for controlling furnaces in furnaces, for determining the oxygen content of Liquids and melts, for determining the oxygen content in the air you breathe of patients, to control carburizing furnaces, to measure oxygen partial pressure in vacuum systems, for measuring the oxygen partial pressure in protective gases, for control purposes of kilns in the ceramic industry, in gas chromatography and for tracking of plume and vortex formation as well as the gas turnover in furnaces, turbines and gas engines used. However, there has been an automatic method of removing soot from furnaces to date not known.
Der vorliegenden Erfindung liegt die Aufgabe zugrunde, ein automatisches Entrußungsverfahren anzugeben, bei dem die kontrollierte Verbrennung des Rußes durch eine geeignete Meßeinrichtung überwacht und der Zeitpunkt der vollständigen Verbrennung hinreichend genau bestimmt werden kann.The present invention is based on the object of an automatic Specify the soot removal process in which the controlled combustion of the soot is carried out a suitable measuring device monitors and the time of complete combustion can be determined with sufficient accuracy.
Diese Aufgabe wird dadurch gelöst, daß die in den Ofen eingeleitete Luftmenge so gesteuert wird, daß im Ofen Luftunterschuß herrscht und gleichzeitig die Ofentemperatur gegenüber der vorgewählten Entrußungstemperatur um höchstens 2000 C ansteigt, und daß der Entrußungsvorgang beendet wird, sobald im Ofen Luftüberschuß auftritt. Mit dem erfindungsgemäßen Verfahren wird der Entrußungsvorgang so gesteuert, daß der unerwünschte Ruß nicht im eigentlichen Sinne verbrannt, sondern langsam oxidiert wird. Zu diesem Zweck wird die Temperaturerhöhung auf vorzugsweise etwa 500 C begrenzt. Durch diese Begrenzung wird sichergestellt, daß lokale Überhitzungen größeren Ausmaßes im Ofen nicht auftreten. Die Begrenzung der Temperaturerhöhung wird durch Steuerung der eingeleiteten Luftmenge erreicht; bei zunehmender Temperatur wird die Luftzufuhr gedrosselt bzw. abgestellt, bei absinkender Temperatur wieder erhöht. Während des ganzen Entrußungsvorgangs herrscht in der Ofenatmosphäre jedoch Luftunterschuß, da der Sauerstoff der Luft für die Oxidation des Rußes verbraucht wird. Bei einer derartigen Steuerung ist das Auftreten von Luftüberschuß in der Ofenatmosphäre ein sicheres Indiz dafür, daß aller verfügbarer Kohlenstoff oxidiert und damit der Entrußungsvorgang abgeschlossen ist.This object is achieved in that the introduced into the furnace The amount of air is controlled so that there is a deficit of air in the furnace and at the same time the furnace temperature compared to the preselected de-sooting temperature by at most 2000 C rises, and that the de-sooting process is terminated as soon as there is excess air in the furnace occurs. With the method according to the invention, the de-sooting process is controlled in such a way that that the unwanted soot is not actually burned, but slowly is oxidized. For this purpose, the temperature is preferably increased to about 500 C limited. This limitation ensures that local overheating large proportions do not occur in the oven. The limitation of the temperature increase is achieved by controlling the amount of air introduced; with increasing temperature the air supply is throttled or shut off, again when the temperature drops elevated. However, the atmosphere in the furnace prevails during the entire de-sooting process Air deficit, as the oxygen in the air is used up for the oxidation of the soot will. With such control, the occurrence of excess air is in the Furnace atmosphere is a sure sign that all available carbon is oxidizing and thus the delusional process is completed.
Vorzugsweise wird der Sauerstoffanteil in der Ofenatmosphäre mit einer Zirkondioxid-Sauerstoffsonde gemessen.The oxygen content in the furnace atmosphere is preferably with a Zirconium dioxide oxygen probe measured.
Eine derartige Meßsonde eignet sich besonders, da sie am Übergangs punkt zwischen Sauerstoffunterschuß und Sauerstoffüberschuß der Ofenatmosphäre eine besonders große Empfindlichkeit besitzt und somit durch schnelle, größere Änderungen der Ausgangsspannung das Ende der Entrußung signalisiert. Bei Unterschreiten einer vorgegebenen Sondenspannung im Bereich des Steilabfalles wird die Zugabe von Luft abgestellt. Die Entrußung ist beendet.Such a measuring probe is particularly suitable because it is at the transition point between the oxygen deficit and the oxygen surplus in the furnace atmosphere has particularly great sensitivity and thus through rapid, larger changes the output voltage signals the end of the soot removal. When falling below a predetermined probe voltage in the area of the steep drop is the addition of air switched off. The rousing is over.
Vorzugsweise wird beim Übergang vom Aufkohlen zum Entrußen die Zufuhr von Bekohlungsgas, wofür im allgemeinen Endogas verwendet wird, erst abgestellt, wenn die Ofen-Temperatur auf den Entrußungswert abgesenkt ist. Bei Erreichen der Entrußungstemperatur wird die Ofenheizung wieder eingeschaltet, um einen weiteren Temperaturabfall zu vermeiden. Gleichzeitig wird über einen Durchflußmengenmesser Luft an einer oder mehreren Stellen in den Ofen eingeleitet.The feed is preferably used during the transition from carburizing to de-sooting of coaling gas, for which endogas is generally used, only switched off, when the furnace temperature has dropped to the sooting value. Upon reaching the Soot removal temperature, the furnace heating is switched on again and another Avoid temperature drop. At the same time a flow meter is used Air introduced into the furnace in one or more places.
Der gerätetechnische Aufwand zur Durchführung des erfindungsgemäßen Verfahrens ist äußerst gering, da Thermometer in Ofenanlagen regelmäßig und Sauerstoffsonden in modernen Anlagen zunehmend vorhanden sind. Prinzipiell könnte der Sauerstoffpartialdruck indirekt auch über den CO- oder H2-Anteil in der Ofenatmosphäre bestimmt werden. Die Ausgangssignale der beiden Meßeinrichtungen werden in einer einfachen Funktionsschaltung dahingehend verknüpft, daß mit Hilfe der Luftzufuhr die Temperaturerhöhung unter vorzugsweise ca. 50°C bleibt und daß bei Auftreten von Luftüberschuß, d.h. bei Unterschreiten eines vorgegebenen Signalwertes an der Lambda-Sonde der Entrußungsvorgang beendet und somit der Ofen auf seinen bestimmungsgemäßen Betrieb umgeschaltet wird.The technical equipment required to carry out the invention Procedure is extremely low, as thermometers in furnace systems are regular and oxygen probes are increasingly present in modern systems. In principle, the partial pressure of oxygen could can also be determined indirectly via the CO or H2 content in the furnace atmosphere. The output signals of the two measuring devices are in a simple functional circuit linked to the effect that with the help of the air supply, the temperature increase below preferably remains around 50 ° C and that if there is an excess of air, i.e. if it falls below the temperature A predetermined signal value at the lambda probe ends the soot removal process and thus the furnace is switched to its normal operation.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19782841626 DE2841626C2 (en) | 1978-09-25 | 1978-09-25 | Process for de-sooting furnaces for fully automatic gas carburizing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19782841626 DE2841626C2 (en) | 1978-09-25 | 1978-09-25 | Process for de-sooting furnaces for fully automatic gas carburizing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| DE2841626A1 true DE2841626A1 (en) | 1980-04-03 |
| DE2841626C2 DE2841626C2 (en) | 1982-06-24 |
Family
ID=6050356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE19782841626 Expired DE2841626C2 (en) | 1978-09-25 | 1978-09-25 | Process for de-sooting furnaces for fully automatic gas carburizing |
Country Status (1)
| Country | Link |
|---|---|
| DE (1) | DE2841626C2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0047067A1 (en) * | 1980-08-15 | 1982-03-10 | Air Products And Chemicals, Inc. | Method for removing carbonaceous deposits from heat treating furnace |
| EP1306462A2 (en) * | 2001-10-23 | 2003-05-02 | Schwäbische Härtetechnik Ulm GmbH | Process and apparatus for measuring and controlling the carburising atmosphere in a vacuum carburising installation |
| WO2003085396A2 (en) * | 2002-04-10 | 2003-10-16 | Linde Aktiengesellschaft | Device and method for controlling the composition of a gaseous atmosphere |
-
1978
- 1978-09-25 DE DE19782841626 patent/DE2841626C2/en not_active Expired
Non-Patent Citations (1)
| Title |
|---|
| NICHTS-ERMITTELT * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0047067A1 (en) * | 1980-08-15 | 1982-03-10 | Air Products And Chemicals, Inc. | Method for removing carbonaceous deposits from heat treating furnace |
| EP1306462A2 (en) * | 2001-10-23 | 2003-05-02 | Schwäbische Härtetechnik Ulm GmbH | Process and apparatus for measuring and controlling the carburising atmosphere in a vacuum carburising installation |
| EP1306462A3 (en) * | 2001-10-23 | 2003-10-29 | Schwäbische Härtetechnik Ulm GmbH | Process and apparatus for measuring and controlling the carburising atmosphere in a vacuum carburising installation |
| WO2003085396A2 (en) * | 2002-04-10 | 2003-10-16 | Linde Aktiengesellschaft | Device and method for controlling the composition of a gaseous atmosphere |
| WO2003085396A3 (en) * | 2002-04-10 | 2004-03-25 | Linde Ag | Device and method for controlling the composition of a gaseous atmosphere |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2841626C2 (en) | 1982-06-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 8110 | Request for examination paragraph 44 | ||
| D2 | Grant after examination | ||
| 8327 | Change in the person/name/address of the patent owner |
Owner name: RUHRGAS AG, 4300 ESSEN, DE |
|
| 8339 | Ceased/non-payment of the annual fee |