EP0008667B1 - Furnace for the thermal treatment of granular or fine sized material - Google Patents

Furnace for the thermal treatment of granular or fine sized material Download PDF

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Publication number
EP0008667B1
EP0008667B1 EP79102695A EP79102695A EP0008667B1 EP 0008667 B1 EP0008667 B1 EP 0008667B1 EP 79102695 A EP79102695 A EP 79102695A EP 79102695 A EP79102695 A EP 79102695A EP 0008667 B1 EP0008667 B1 EP 0008667B1
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EP
European Patent Office
Prior art keywords
furnace
fan
cooling
furnace according
shaft
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EP79102695A
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German (de)
French (fr)
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EP0008667A1 (en
Inventor
Heinrich Buchner
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Kloeckner Humboldt Deutz AG
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Kloeckner Humboldt Deutz AG
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Priority to AT79102695T priority Critical patent/ATE67T1/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/02—Blade-carrying members, e.g. rotors
    • F01D5/08—Heating, heat-insulating or cooling means
    • F01D5/085—Heating, heat-insulating or cooling means cooling fluid circulating inside the rotor
    • 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
    • F27B1/00—Shaft or like vertical or substantially vertical furnaces
    • F27B1/06—Shaft or like vertical or substantially vertical furnaces of other than up-draught type

Definitions

  • the invention relates to a furnace for the heat treatment of lumpy to fine-grained material, in particular a shaft furnace, rotary hearth furnace or the like for burning or sintering limestone, dolomite or magnesite, in which the furnace passes through a preheating zone, a combustion zone and a cooling zone and the combustion zone has a gas supply. or gas extraction chamber, a combustion device and a gas delivery device for generating a hot gas circulation.
  • a cross-flow shaft furnace is known from DE-B-1034090, which has gas collection devices and heating devices.
  • the hot gases required for sintering the fuel are collected in the gas collection devices after flowing through the material layer and heated again in the heating devices by means of injectors for the gas circulation.
  • the funding required for the gas circulation is represented by the rigid injectors, which circulate an essentially constant throughput volume of hot gases. Faults occur in such a cross-flow shaft furnace in particular when the gas volume available to the respective injector is changed due to a changed bulk density in the shaft and thus a changed pressure resistance in the man-made column.
  • a cross-flow heated shaft kiln for limestone firing which has a preheating zone, two firing zones and a cooling zone in the direction of passage of the material, each firing zone containing a quasi-closed hot gas circuit.
  • the hot gas circuit is brought about by assigning at least one jet blower or injector to each combustion zone, which generates the kinetic energy required for the hot gas circulation.
  • the hot gases are circulated from the injector into a combustion chamber, a gas collection chamber, the assigned fuel bed, the exhausting gas collection chamber and a circulation channel back to the injector. Fuel and cooling air from the cooling zone are introduced into the combustion chamber.
  • the intense hot gas circulation results in a very even fire across the entire shaft cross-section.
  • a heat treatment furnace in particular a shaft furnace for burning or sintering limestone, dolomite or magnesite, in such a way that furnace units of up to 400 t throughput, low specific, can be used with structurally simple means Energy consumption and high thermal efficiency can be built.
  • the gas delivery device which is preferably arranged between the gas discharge chamber and the combustion device, is a delivery fan charged with coolant.
  • the cooled gas delivery fan is arranged in the hot circulation channel between the gas discharge chamber and the combustion chamber, which makes it particularly compact and achieve compact furnace construction.
  • the conveying fan is arranged on the outside of the shaft and is connected to a cooling device with a closed coolant guide.
  • This has the advantage that highly effective coolants are fed to the blower in a closed circuit, so that the temperatures on the blower can be set precisely and the blower parts are never exposed to undesirably high temperature ranges.
  • the volatile constituents in the hot gases which tend to cake, crystallize directly on the relatively cold blower parts and are returned as solid constituents to the bulk material without the blower even with a very high volatile content Harmful components in the hot gases have no caking. This ensures high operational reliability and availability of the blower and thus the entire furnace system.
  • the recooler of the fan cooling device serves as a heat exchanger for the fuels introduced into the combustion chamber.
  • the fan shaft and / or the fan wheel is hollow and in the fan shaft or in the fan ring gear coolant-carrying devices, preferably coolant lines, are arranged, whereby the fan parts are specifically cooled there where the thermal stress from the hot gases is strongest.
  • the coolant lines of the blower shaft are connected to the fixed coolant lines of the recooler via a stationary distributor head, which is preferably designed as an air-flowed honeycomb cooler or tube cooler. This constructive design is particularly advantageous when no fuel preheating is required with the recooler, such as with coal dust.
  • the coolant is then preferably recooled with the aid of a cooler through which air flows.
  • the coolant lines in the blower hollow shaft are formed from a hollow cylinder which is coaxially oriented at a distance from the hollow shaft, the coolant being supplied through the resulting outer annular space and the coolant being discharged through the hollow cylinder. In conjunction with the stationary distributor head, this results in optimal coolant flow with the lowest hydraulic resistance. It is furthermore expedient that the coolant line in the fan wheel preferably runs in a meandering fashion at the outer end of each wheel blade, which ensures that, particularly where high thermal loads on the fan blades are to be expected, optimal dissipation of the heat is achieved by an increased supply of coolant.
  • blower ring gear is connected to the hollow cylinder in the blower shaft via connecting lines in the wheel hub, so that an optimal coolant circulation, in particular on the thermally stressed parts of the blower, is achieved with simple constructional means.
  • the coolant for the conveying fan and / or the fan parts is a temperature-resistant organic or inorganic liquid with a boiling point of more than 100 ° C. This measure achieves high heat dissipation and thus improved cooling of the individual blower parts at a relatively low liquid temperature, as a result of which, in particular, heat peaks on the blower parts can be reduced.
  • the cross sections of the coolant lines can be chosen to be so small that coolant lines can also be laid in more complex fan parts. Due to the closed circuit of the coolant, expensive, highly effective coolants can also be used, since the coolant does not have to be added continuously.
  • the cooling liquid for the blower is a heat transfer oil, in particular a silicone oil, whereby it is advantageously achieved that the desired working temperature of more than 100 ° C. is achieved with a commercially available coolant. It is expedient that the working temperature of the cooling liquid is set between 200 and 270 ° C, preferably between 200 and 220 ° C.
  • one embodiment of the invention provides that the coolant circuit for the delivery fan is monitored by pressure monitors, thermostats, flow meters, etc.
  • a direct-acting, safe system for monitoring the cooling circuit is available, which immediately indicates a rise in temperature and / or a throughput fault in the cooling liquid, so that immediate countermeasures can be initiated. This ensures reliable cooling of the fan with regard to the material properties.
  • a cross-flow heated shaft furnace 1 is partially shown in section.
  • the furnace shaft 2 is divided into an upper preheating zone V, two firing zones B 1 / B 2 arranged underneath and a cooling zone K.
  • a device At the lower end of the shaft is a device, not shown, for the continuous removal of the fired material.
  • the rectangular shaft 2 consists of two gas collection chambers arranged on both sides of the shaft, one chamber representing the gas supply chamber 3 and the other the gas discharge chamber 4.
  • the shaft wall 6 provided with gas passage openings 5 runs between these two chambers.
  • the firing material 7 moves inside the shaft from top to bottom in a dense column of firing material.
  • the Gas supply chamber 3 is connected to a combustion chamber 8, into which a combustion device 9 and a fresh air line 13 are guided, through which hot air from the cooling zone K is conducted as combustion air into the combustion chamber 8.
  • the gas discharge chamber 4 has a discharge opening 10 in the upper region, to which a circulation channel 11 is connected, which in turn is guided into the combustion chamber 8.
  • a conveying fan 12 charged with coolants is arranged to maintain a closed hot gas circulation in the combustion zone B 2 .
  • a branch line from the fresh air line 13 can be connected to the circulation channel 11.
  • the combustion chamber 8, the combustion device 9 and the conveying fan 12 arranged in the circulation channel 11 are arranged outside the shaft and are therefore shown in broken lines.
  • the conveying fan 12 is connected to a cooling device 14 which is arranged outside the shaft and has a self-contained coolant guide.
  • the supply of the coolant to the hot gas blower 12 takes place through line 15 and the return to the air-cooled recooler 16 through line 17.
  • the lines 15, 17 contain the measuring and control devices required for monitoring the coolant circuit, in each case in each supply and return line 15, 17 a pressure switch 18 and a quick-closing thermostat valve 19. Furthermore, the lines 15 and 17 have flow meters 20 for the cooling liquid, which are designed as orifice measuring devices with differential pressure gauges.
  • a pneumatic valve 21 is arranged in line 15 for quick shutdown of the coolant supply.
  • an expansion tank 22 is arranged at the highest point of the circuit to compensate for the change in volume of the coolant, and in front of the coolant pump 23 there is a fill and refill tank 24 for the coolant.
  • the honeycomb cooler 16 is air-cooled and equipped with an adjustable cooling fan 25.
  • FIG. 2 shows, in section and in an enlarged view, the conveying fan 12 arranged on the outside of the shaft in the circulation channel 11, in particular the fan shaft 26 and the fan wheel 27. Both the fan shaft 26 and the fan wheel 27 are hollow.
  • a hollow cylinder 28 is arranged coaxially in the hollow blower shaft 26 at a distance from the hollow shaft itself, the coolant being supplied through the resulting outer annular space 32 and being discharged through the hollow cylinder 28.
  • the coolant annulus as well as the hollow cylinder are connected via a stationary distributor head 29 to the stationary coolant lines 15 and 17, which in turn form a closed coolant circuit with the honeycomb cooler 16 through which air flows.
  • the distributor head 29 is surrounded by a leakage housing known per se.
  • guide plates 31 are arranged at the outer end of each wheel blade 30 and meandering band-shaped, to which the coolant is supplied from the annular space 32 of the fan shaft 26 via a line 33 arranged in the fan wheel.
  • the interior of the blower ring gear 27 is connected to the hollow cylinder 28 via a connecting line 34 which are arranged in the wheel hub 35 of the blower wheel 27.
  • the hot gases generated in the combustion chamber 8 flow from the combustion chamber into the gas supply chamber 3 and from there through the gas passage openings 5 in the shaft wall 6 transversely to the throughput direction of the Fired goods enter the densely packed fired goods layer, enter the gas discharge chamber 4 on the other side of the bed through the gas passage openings 5 and are collected there.
  • the hot gas is sucked out of the gas discharge chamber 4 via the discharge opening 10 into the circulation channel 11 by means of the delivery fan 12, which is thus directly in a hot gas flow of approximately 800 ° C. to 1200 ° C.
  • the conveying fan 12 feeds the hot gas to the combustion chamber 8, into which fuels are introduced via the combustion device 9 and burn out there in the atmosphere enriched with preheated fresh air.
  • the hot gas circuit in each combustion zone B is supplied with the kinetic energy required for the multiple circulation of the hot gases in the combustion zone, the fan making it possible to set a precisely adjustable pressure drop of at least 350 mm / WS within each combustion zone.
  • each combustion zone B 1 / B In order to prevent the gases flowing through the shaft 2 in the vertical direction upwards, two sealing zones are arranged between each combustion zone B 1 / B and prevent the hot gases from flowing out into the overlying combustion zone or preheating zone.
  • the combustible material that descends from the combustion zone into the cooling zone K is cooled to the appropriate further processing temperature in the cooling air 36 and is further processed via extraction elements (not shown).
  • the cooling air heated in the cooling zone releases the amount of heat absorbed by the material to be burned into the combustion chamber 8 as combustion air.
  • a portion of the hot gases generated in the combustion zones B and B 2 is branched off from the combustion zones and is fed to the lumpy material in the preheating zone for preheating it via lines not shown in the furnace 1 headed.
  • the conveying fan 12 is connected via the distributor head 29 to a closed cooling circuit 14 which is designed as described above.
  • the cooling of the blower with the cooling device takes place by means of a temperature-resistant heat transfer oil, in particular a silicone oil, which is regulated to a working temperature between 200 and 220 ° C, for which purpose corresponding control devices, such as pressure switch 18, thermostatic valve 19 and flow meter 20, are located in the fixed coolant lines of the cooling device are arranged.
  • a temperature-resistant heat transfer oil in particular a silicone oil, which is regulated to a working temperature between 200 and 220 ° C, for which purpose corresponding control devices, such as pressure switch 18, thermostatic valve 19 and flow meter 20, are located in the fixed coolant lines of the cooling device are arranged.
  • blower parts in the hot gas stream heated to a maximum of 240 ° C, shock-cool the alkali or sulfur compounds that volatilize from the fired material and tend to cake and crystallize out of the hot gases, so that none on the blower or blower blades Can form approaches that either negatively affect the throughput characteristics of the blower or lead to increased bearing loads on the blower.
  • blower which is cooled with a heat transfer oil in a closed circuit, directly in the hot gas circulation of the combustion zone of a cross-flow-heated shaft furnace, it is possible to generate such a high pressure drop in each combustion zone and thus to provide such a high kinetic energy for the hot gas circulation that furnace units with double Throughput compared to crossflow furnaces equipped with injectors are possible.
  • the present invention which is only described for cross-flow heated shaft furnaces for burning or sintering limestone, dolomite or magnesite, can be used wherever blowers must be used directly in a hot gas stream in order to generate the kinetic energy required for gas production.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Furnace Details (AREA)
  • Tunnel Furnaces (AREA)
  • Crucibles And Fluidized-Bed Furnaces (AREA)
  • Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
  • Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
  • Muffle Furnaces And Rotary Kilns (AREA)

Abstract

A furnace is disclosed for the heat treatment of mainly lumpy to fine grained material. The furnace is either a shaft furnace or a rotary furnace for the calcination or sintering of limestone, dolomite or magnesite. The calcination material passes through a preheating zone, a calcination zone and a cooling zone. The calcination zone has a gas feed and gas withdrawal device. A calcination device is provided in the calcination zone to which is connected a gas conveying device for the production of a hot gas circulation. The hot gas circulation device is situated between the gas withdrawal device and the calcination device and is provided as a conveying blower subjected to a cooling liquid.

Description

Die Erfindung betrifft einen Ofen zur Wärmebehandlung von stückigem bis feinkörnigem Gut, insbesondere Schachtofen, Drehherdofen oder dergleichen zum Brennen oder Sintern von Kalkstein, Dolomit oder Magnesit, in welchem Ofen das Brenngut eine Vorwärmzone, eine Brennzone sowie eine Kühlzone durchsetzt und die Brennzone eine Gaszufuhr- bzw. Gasabzugskammer, eine Brenneinrichtung sowie eine Gasfördereinrichtung zur Erzeugung eines Heissgasumlaufes aufweist.The invention relates to a furnace for the heat treatment of lumpy to fine-grained material, in particular a shaft furnace, rotary hearth furnace or the like for burning or sintering limestone, dolomite or magnesite, in which the furnace passes through a preheating zone, a combustion zone and a cooling zone and the combustion zone has a gas supply. or gas extraction chamber, a combustion device and a gas delivery device for generating a hot gas circulation.

Aus der DE-B-1034090 ist ein Querstromschachtofen bekannt, der Gassammeleinrichtungen und Heizeinrichtungen aufweist. Die zum Sintern des Brenngutes erforderlichen Heissgase werden nach dem Durchströmen der Gutschicht in den Gassammeleinrichtungen aufgefangen und in den Heizeinrichtungen mittels Injektoren für die Gasumwälzung wieder aufgeheizt. Die für den Gasumlauf erforderlichen Fördermittel werden dabei durch die starren Injektoren dargestellt, die ein im wesentlichen konstantes Durchsatzvolumen von Heissgasen umwälzen. Störungen treten bei einem solchen Querstromschachtofen insbesondere dann auf, wenn aufgrund einer veränderten Schüttdichte im Schacht und damit verändertem Druckwiderstand in der Gutsäule das dem jeweiligen Injektor zur Verfügung stehende Gasvolumen geändert wird.A cross-flow shaft furnace is known from DE-B-1034090, which has gas collection devices and heating devices. The hot gases required for sintering the fuel are collected in the gas collection devices after flowing through the material layer and heated again in the heating devices by means of injectors for the gas circulation. The funding required for the gas circulation is represented by the rigid injectors, which circulate an essentially constant throughput volume of hot gases. Faults occur in such a cross-flow shaft furnace in particular when the gas volume available to the respective injector is changed due to a changed bulk density in the shaft and thus a changed pressure resistance in the man-made column.

Aus der DE-B-1 558057 ist ein querstrombeheizter Schachtofen zum Brennen von Kalkstein bekannt, der in Durchgangsrichtung des Gutes eine Vorwärmzone, zwei Brennzonen und eine Kühlzone aufweist, wobei jede Brennzone einen quasi geschlossenen Heissgaskreislauf enthält. Der Heissgaskreislauf wird dadurch bewirkt, dass jeder Brennzone mindestens ein Strahlgebläse bzw. Injektor zugeordnet ist, welcher die für den Heissgasumlauf erforderliche kinetische Energie erzeugt. Der Kreislauf der Heissgase erfolgt vom Injektor aus in eine Brennkammer, eine Gassammelkammer, die zugeordnete Brenngutschicht, die abführende Gassammelkammer und einen Umlaufkanal zurück zum Injektor. In die Brennkammer wird Brennstoff und als Verbrennungsluft Kühlluft aus der Kühlzone eingeführt. Durch die intensive Heissgasumwälzung ergibt sich ein sehr gleichmässiger Brand über den gesamten Schachtquerschnitt. Es hat sich jedoch im Zuge nach immer grösseren Ofeneinheiten gezeigt, dass dem Einsatz von Strahlgebläsen oder Injektoren zur Aufrechterhaltung der Gasumwälzung in einer jeden Brennzone Grenzen gesetzt sind, die insbesondere in dem hohen konstruktiven und kostenträchtigen Aufwand für diese Injektoren liegen. Zum anderen lassen sich mit diesen Injektoren pro Brennzone bei grossen Ofeneinheiten nur unzureichende Druckgefälle bis ca. 70 mm WS erzeugen, so dass bei den grossen Ofeneinheiten die für den Heissgaskreislauf erforderliche kinetische Energie mit Injektoren nicht mehr erzeugt werden kann. Deshalb liessen sich nur Ofeneinheiten bis zu 120 t Durchsatz darstellen.From DE-B-1 558057 a cross-flow heated shaft kiln for limestone firing is known which has a preheating zone, two firing zones and a cooling zone in the direction of passage of the material, each firing zone containing a quasi-closed hot gas circuit. The hot gas circuit is brought about by assigning at least one jet blower or injector to each combustion zone, which generates the kinetic energy required for the hot gas circulation. The hot gases are circulated from the injector into a combustion chamber, a gas collection chamber, the assigned fuel bed, the exhausting gas collection chamber and a circulation channel back to the injector. Fuel and cooling air from the cooling zone are introduced into the combustion chamber. The intense hot gas circulation results in a very even fire across the entire shaft cross-section. However, in the course of ever larger furnace units, it has been shown that there are limits to the use of jet blowers or injectors for maintaining the gas circulation in each combustion zone, which lie in particular in the high constructional and costly outlay for these injectors. On the other hand, these injectors can only produce insufficient pressure drops of up to approx. 70 mm WS per combustion zone for large furnace units, so that the kinetic energy required for the hot gas circuit can no longer be generated with injectors in the large furnace units. Therefore, only furnace units with a throughput of up to 120 t could be represented.

Ausgehend von dem eingangs gewürdigten Stand der Technik ist es die Aufgabe der vorliegenden Erfindung, einen Wärmebehandlungsofen, insbesondere einen Schachtofen zum Brennen oder Sintern von Kalkstein, Dolomit oder Magnesit so zu verbessern, dass mit konstruktiv einfachen Mitteln Ofeneinheiten bis zu 400 t Durchsatz, geringem spezifischen Energieverbrauch und hohem thermischen Wirkungsgrad gebaut werden können.Starting from the prior art recognized at the outset, it is the object of the present invention to improve a heat treatment furnace, in particular a shaft furnace for burning or sintering limestone, dolomite or magnesite, in such a way that furnace units of up to 400 t throughput, low specific, can be used with structurally simple means Energy consumption and high thermal efficiency can be built.

Diese Aufgabe wird dadurch gelöst, dass die vorzugsweise zwischen der Gasabzugskammer und der Brenneinrichtung angeordnete Gasfördereinrichtung ein mit Kühlmittel beaufschlagtes Fördergebläse ist.This object is achieved in that the gas delivery device, which is preferably arranged between the gas discharge chamber and the combustion device, is a delivery fan charged with coolant.

Hierdurch ist es möglich, direkt im Heissgasumlauf eine optimale regulierbare Gasfördereinrichtung einzusetzen, die im Gegensatz zu den starren Injektoren ohne weiteres in der Brennzone ein Druckgefälle von ca. 300 mm Wassersäule erzeugt, so dass weitaus grössere Gasmengen pro Zeiteinheit an das zu brennende/sinternde Brenngut herangeführt werden können. Dieses mit Kühlmitteln beaufschlagte Fördergebläse kann also ohne weiteres Heissgase bis ca. 1200°C im Umlauf zwischen Gasabzugseinrichtung und Brenneinrichtung fördern, ohne dass das Gebläse thermischen Grenzbeanspruchungen ausgesetzt ist. Die aufwendigen konstruktiven Bauten für die Anordnung der Injektoren am Brennschacht können entfallen, so dass insgesamt die Investitionskosten für die Ofenanlage erheblich gesenkt werden können.This makes it possible to use an optimally adjustable gas delivery device directly in the hot gas circulation, which, in contrast to the rigid injectors, easily generates a pressure drop of approx. 300 mm water column in the firing zone, so that far larger amounts of gas per unit time are burned / sintered can be introduced. This conveying blower, which is acted on with coolants, can therefore convey hot gases up to approximately 1200 ° C. in the circulation between the gas extraction device and the combustion device without the blower being exposed to thermal limit stresses. The elaborate structural structures for the arrangement of the injectors on the combustion shaft can be dispensed with, so that overall the investment costs for the furnace system can be considerably reduced.

In Ausgestaltung der Erfindung ist vorgesehen, dass bei einem querstrombeheizten Schachtofen mit mindestens einer Brennzone und seitlich am Schacht angeordneter und jeder Brennzone zugeordneter Gaszufuhr- bzw. Gasabzugskammer das gekühlte Gasfördergebläse im heissen Umlaufkanal zwischen der Gasabzugskammer und der Brennkammer angeordnet ist, wodurch sich eine besonders kompakte und gedrungene Ofenkonstruktion erzielen lässt.In an embodiment of the invention it is provided that in a cross-flow-heated shaft furnace with at least one combustion zone and gas supply or gas discharge chamber arranged on the side of the shaft and assigned to each combustion zone, the cooled gas delivery fan is arranged in the hot circulation channel between the gas discharge chamber and the combustion chamber, which makes it particularly compact and achieve compact furnace construction.

In weiterer Ausgestaltung der Erfindung ist vorgesehen, dass das Fördergebläse aussen am Schacht angeordnet ist und an eine Kühlvorrichtung mit in sich geschlossener Kühlmittelführung angeschlossen ist. Dies hat den Vorteil, dass hochwirksame Kühlmittel im geschlossenen Kreislauf dem Gebläse zugeführt werden, so dass eine exakte Einstellung der Temperaturen am Gebläse erfolgen kann und die Gebläseteile in keinem Fall unerwünscht hohen Temperaturbereichen ausgesetzt sind. Zum anderen wird erreicht, dass die flüchtigen und zu Anbackungen neigenden Bestandteile in den Heissgasen direkt an den relativ kalten Gebläseteilen auskristallisieren und als feste Bestandteile in die Gutschüttung zurückgeführt werden, ohne dass das Gebläse auch bei einem sehr hohen Gehalt an flüchtigen Schadbestandteilen in den Heissgasen keine Anbackungen aufweist. Hierdurch wird eine hohe Betriebssicherheit und Verfügbarkeit des Gebläses und damit der gesamten Ofenanlage erreicht.In a further embodiment of the invention it is provided that the conveying fan is arranged on the outside of the shaft and is connected to a cooling device with a closed coolant guide. This has the advantage that highly effective coolants are fed to the blower in a closed circuit, so that the temperatures on the blower can be set precisely and the blower parts are never exposed to undesirably high temperature ranges. On the other hand, it is achieved that the volatile constituents in the hot gases, which tend to cake, crystallize directly on the relatively cold blower parts and are returned as solid constituents to the bulk material without the blower even with a very high volatile content Harmful components in the hot gases have no caking. This ensures high operational reliability and availability of the blower and thus the entire furnace system.

In weiterer Ausgestaltung der Erfindung ist vorgesehen, dass der Rückkühler der Gebläsekühlvorrichtung als Wärmetauscher für die in die Brennkammer eingeführten Brennstoffe dient. Hierdurch wird eine optimale Nutzung der vom Gebläse angeführten Wärme erreicht und insbesondere bei ölbefeuerten Brennkammern durch die Vorwärmung der Brennstoffe deren schnellere Vergasung in der Brennkammer und damit eine optimale Verbrennung ohne Zündverzögerung erzielt.In a further embodiment of the invention, it is provided that the recooler of the fan cooling device serves as a heat exchanger for the fuels introduced into the combustion chamber. In this way, optimal use of the heat supplied by the blower is achieved and, in particular in the case of oil-fired combustion chambers, the preheating of the fuels causes them to be gasified more quickly in the combustion chamber and thus optimal combustion without ignition delay.

In einer weiteren Ausgestaltung der Erfindung ist vorgesehen, dass beim Fördergebläse die Gebläsewelle und/oder das Gebläserad hohl ausgebildet ist und in der Gebläsehohlwelle bzw. in dem Gebläsehohlrad kühlmittelführende Einrichtungen, vorzugsweise Kühlmittelleitungen angeordnet sind, wodurch erreicht wird, dass die Gebläseteile gezielt dort gekühlt werden können, wo die thermische Belastung durch die Heissgase am stärksten ist. Zweckmässig ist hierbei, dass die Kühlmittelleitungen der Gebläsewelle über einen ortsfesten Verteilerkopf mit den ortsfesten Kühlmittelleitungen des Rückkühlers in Verbindung stehen, der vorzugsweise als luftdurchströmter Wabenkühler oder Röhrenkühler ausgebildet ist. Diese konstruktive Ausbildung ist insbesondere dann von Vorteil, wenn mit dem Rückkühler keine Brennstoffvorwärmung wie zum Beispiel bei Kohlenstaub erforderlich ist. Die Rückkühlung des Kühlmittels erfolgt dann vorzugsweise mit Hilfe eines luftdurchströmten Kühlers.In a further embodiment of the invention it is provided that in the conveying fan the fan shaft and / or the fan wheel is hollow and in the fan shaft or in the fan ring gear coolant-carrying devices, preferably coolant lines, are arranged, whereby the fan parts are specifically cooled there where the thermal stress from the hot gases is strongest. It is expedient here that the coolant lines of the blower shaft are connected to the fixed coolant lines of the recooler via a stationary distributor head, which is preferably designed as an air-flowed honeycomb cooler or tube cooler. This constructive design is particularly advantageous when no fuel preheating is required with the recooler, such as with coal dust. The coolant is then preferably recooled with the aid of a cooler through which air flows.

In bevorzugter Ausgestaltung der Erfindung ist vorgesehen, dass die Kühlmittelleitungen in der Gebläsehohlwelle aus einem mit Abstand zur Hohlwelle koaxial ausgerichteten Hohlzylinder gebildet werden, wobei durch den entstehenden äusseren Ringraum das Kühlmittel zugeführt und durch den Hohlzylinder das Kühlmittel abgeführt wird. Dies ergibt in Verbindung mit dem ortsfesten Verteilerkopf eine optimale Kühlmittelführung mit geringsten hydraulischen Widerständen. Zweckmässig ist weiterhin, dass die Kühlmittelleitung im Gebläserad vorzugsweise am äusseren Ende einer jeden Radschaufel mäanderbandförmig verlaufen, wodurch sichergestellt ist, dass insbesondere dort wo hohe Wärmebelastungen an den Gebläseschaufeln zu erwarten sind, eine optimale Abführung der Wärme durch erhöhtes Kühlmittelangbot erzielt wird.In a preferred embodiment of the invention, it is provided that the coolant lines in the blower hollow shaft are formed from a hollow cylinder which is coaxially oriented at a distance from the hollow shaft, the coolant being supplied through the resulting outer annular space and the coolant being discharged through the hollow cylinder. In conjunction with the stationary distributor head, this results in optimal coolant flow with the lowest hydraulic resistance. It is furthermore expedient that the coolant line in the fan wheel preferably runs in a meandering fashion at the outer end of each wheel blade, which ensures that, particularly where high thermal loads on the fan blades are to be expected, optimal dissipation of the heat is achieved by an increased supply of coolant.

Ein weiterer Vorschlag sieht vor, dass das Gebläsehohlrad über Verbindungsleitungen in der Radnabe mit dem Hohlzylinder in der Gebläsewelle in Verbindung steht, so dass mit einfachen konstruktiven Mitteln ein optimaler Kühlmittelumlauf insbesondere an den thermisch beanspruchten Teilen des Gebläses erreicht wird.Another proposal provides that the blower ring gear is connected to the hollow cylinder in the blower shaft via connecting lines in the wheel hub, so that an optimal coolant circulation, in particular on the thermally stressed parts of the blower, is achieved with simple constructional means.

In einer weiteren bevorzugten Ausgestaltung der Erfindung ist vorgesehen, dass das Kühlmittel für das Fördergebläse und/oder die Gebläseteile eine temperaturbeständige organische oder anorganische Flüssigkeit mit einem Siedepunkt von mehr als 100°C ist. Durch diese Massnahme wird bei relativ niedriger Flüssigkeitstemperatur eine hohe Wärmeabfuhr und damit eine verbesserte Kühlung der einzelnen Gebläseteile erreicht, wodurch insbesondere Wärmespitzen an den Gebläseteilen abgebaut werden können. Ausserdem können die Querschnitte der Kühlmittelleitungen so klein gewählt werden, dass auch in komplizierter gestaltete Gebläseteile Kühlmittelleitungen verlegt werden können. Durch den geschlossenen Kreislauf des Kühlmittels können auch teure hochwirksame Kühlmittel verwendet werden, da die Kühlflüssigkeit nicht laufend neu zugeführt werden muss.In a further preferred embodiment of the invention it is provided that the coolant for the conveying fan and / or the fan parts is a temperature-resistant organic or inorganic liquid with a boiling point of more than 100 ° C. This measure achieves high heat dissipation and thus improved cooling of the individual blower parts at a relatively low liquid temperature, as a result of which, in particular, heat peaks on the blower parts can be reduced. In addition, the cross sections of the coolant lines can be chosen to be so small that coolant lines can also be laid in more complex fan parts. Due to the closed circuit of the coolant, expensive, highly effective coolants can also be used, since the coolant does not have to be added continuously.

In Ausgestaltung der Erfindung ist weiterhin vorgesehen, dass die Kühlflüssigkeit für das Gebläse ein Wärmeträgeröl, insbesondere ein Silikonöl ist, wodurch mit Vorteil erreicht wird, dass die angestrebte Arbeitstemperatur von mehr als 100°C mit einem Kühlmittel handelsüblicher Art erreicht wird. Zweckmässig ist, dass die Arbeitstemperatur der Kühlflüssigkeit zwischen 200 und 270°C, vorzugsweise zwischen 200 und 220°C eingestellt wird.In an embodiment of the invention it is further provided that the cooling liquid for the blower is a heat transfer oil, in particular a silicone oil, whereby it is advantageously achieved that the desired working temperature of more than 100 ° C. is achieved with a commercially available coolant. It is expedient that the working temperature of the cooling liquid is set between 200 and 270 ° C, preferably between 200 and 220 ° C.

Weiterhin ist in einer Ausgestaltung der Erfindung vorgesehen, dass der Kühlflüssigkeitskreislauf für das Fördergebläse durch Druckwächter, Thermostate, Strömungsmesser etc. überwacht wird. Hierdurch steht ein direkt wirkendes, sicheres System zur Überwachung des Kühlkreislaufes zur Verfügung, das einen Temperaturanstieg und/oder eine Durchsatzstörung der Kühlflüssigkeit sofort anzeigt, so dass sofortige Gegenmassnahmen eingeleitet werden können. Hierdurch wird eine zuverlässige Kühlung des Gebläses im Hinblick auf die Materialeigenschaften gewährleistet.Furthermore, one embodiment of the invention provides that the coolant circuit for the delivery fan is monitored by pressure monitors, thermostats, flow meters, etc. As a result, a direct-acting, safe system for monitoring the cooling circuit is available, which immediately indicates a rise in temperature and / or a throughput fault in the cooling liquid, so that immediate countermeasures can be initiated. This ensures reliable cooling of the fan with regard to the material properties.

Nachfolgend wird die Erfindung anhand eines Ausführungsbeispieles näher beschrieben. Es zeigen:

  • Fig. 1: einen Querstromschachtofen teilweise im Schnitt mit im Heissgasumlauf der Brennzone angeordnetem gekühlten Gebläse,
  • Fig.2: einen Längsschnitt durch das gekühlte Fördergebläse in vergrösserter Darstellung.
The invention is described in more detail below using an exemplary embodiment. Show it:
  • 1: a cross-flow shaft furnace partly in section with a cooled fan arranged in the hot gas circulation of the combustion zone,
  • Fig.2: a longitudinal section through the cooled conveyor fan in an enlarged view.

In Fig. 1 ist ein querstrombeheizter Schachtofen 1 teilweise im Schnitt dargestellt. Der Ofenschacht 2 ist in eine obere Vorwärmzone V, zwei darunter angeordnete Brennzonen Bl/B2 und eine Kühlzone K gegliedert. Am unteren Schachtende befindet sich eine nicht näher dargestellte Vorrichtung zum kontinuierlichen Abzug des gebrannten Gutes.In Fig. 1, a cross-flow heated shaft furnace 1 is partially shown in section. The furnace shaft 2 is divided into an upper preheating zone V, two firing zones B 1 / B 2 arranged underneath and a cooling zone K. At the lower end of the shaft is a device, not shown, for the continuous removal of the fired material.

In der Brennzone B2 wie auch in der darüber nicht näher dargestellten Brennzone B1 besteht der rechteckige Schacht 2 aus zwei zu beiden Seiten des Schachtes angeordneten Gassammelkammern, von denen die eine Kammer die Gaszufuhrkammer 3 und die andere die Gasabzugskammer 4 darstellt. Zwischen diesen beiden Kammern verläuft die mit Gasdurchlassöffnungen 5 versehene Schachtwand 6. Innerhalb des Schachtes bewegt sich das Brenngut 7 von oben nach unten in einer dichten Brenngutsäule. Die Gaszufuhrkammer 3 steht mit einer Brennkammer 8 in Verbindung, in die eine Brenneinrichtung 9 und eine Frischluftleitung 13 geführt ist, durch die Heissluft aus der Kühlzone K als Verbrennungsluft in die Brennkammer 8 geleitet wird. Die Gasabzugskammer 4 weist im oberen Bereich eine Abzugsöffnung 10 auf, an die ein Umlaufkanal 11 angeschlossen ist, der seinerseits in die Brennkammer 8 geführt ist. In dem Umlaufkanal 11 ist ein mit Kühlmitteln beaufschlagtes Fördergebläse 12 zur Aufrechterhaltung eines geschlossenen Heissgasumlaufes in der Brennzone B2 angeordnet. Gegebenenfalls kann an den Umlaufkanal 11 eine Zweigleitung aus der Frischluftleitung 13 angeschlossen sein. Die Brennkammer 8, die Brenneinrichtung 9 und das im Umlaufkanal 11 angeordnete Fördergebläse 12 sind ausserhalb des Schachtes angeordnet und insofern in gebrochener Linienführung dargestellt.In the combustion zone B 2, as well as in the combustion zone B 1 not shown above, the rectangular shaft 2 consists of two gas collection chambers arranged on both sides of the shaft, one chamber representing the gas supply chamber 3 and the other the gas discharge chamber 4. The shaft wall 6 provided with gas passage openings 5 runs between these two chambers. The firing material 7 moves inside the shaft from top to bottom in a dense column of firing material. The Gas supply chamber 3 is connected to a combustion chamber 8, into which a combustion device 9 and a fresh air line 13 are guided, through which hot air from the cooling zone K is conducted as combustion air into the combustion chamber 8. The gas discharge chamber 4 has a discharge opening 10 in the upper region, to which a circulation channel 11 is connected, which in turn is guided into the combustion chamber 8. In the circulating channel 11, a conveying fan 12 charged with coolants is arranged to maintain a closed hot gas circulation in the combustion zone B 2 . If necessary, a branch line from the fresh air line 13 can be connected to the circulation channel 11. The combustion chamber 8, the combustion device 9 and the conveying fan 12 arranged in the circulation channel 11 are arranged outside the shaft and are therefore shown in broken lines.

Das Fördergebläse 12 ist an eine ausserhalb des Schachtes angeordnete Kühlvorrichtung 14 mit in sich geschlossener Kühlmittelführung angeschlossen. Die Zuführung der Kühlflüssigkeit zu dem Heissgasgebläse 12 erfolgt dabei durch die Leitung 15 und die Rückführung zu dem luftgekühlten Rückkühler 16 durch die Leitung 17. In den Leitungen 15, 17 befinden sich die für die Überwachung des Kühlmittelkreislaufes erforderlichen Mess- und Regelgeräte, und zwar jeweils in jeder Zu- und Rückführungsleitung 15, 17 ein Druckwächter 18 und ein Schnellschlussthermostatventil 19. Des weiteren weisen die Leitungen 15 und 17 Strömungsmesser 20 für die Kühlflüssigkeit auf, die als Blendenmessgeräte mit Differenzdruckmanometer ausgebildet sind. Zur Schnellabschaltung der Kühlmittelzuführung ist in der Leitung 15 ein pneumatisches Ventil 21 angeordnet.The conveying fan 12 is connected to a cooling device 14 which is arranged outside the shaft and has a self-contained coolant guide. The supply of the coolant to the hot gas blower 12 takes place through line 15 and the return to the air-cooled recooler 16 through line 17. The lines 15, 17 contain the measuring and control devices required for monitoring the coolant circuit, in each case in each supply and return line 15, 17 a pressure switch 18 and a quick-closing thermostat valve 19. Furthermore, the lines 15 and 17 have flow meters 20 for the cooling liquid, which are designed as orifice measuring devices with differential pressure gauges. A pneumatic valve 21 is arranged in line 15 for quick shutdown of the coolant supply.

In der Kühlmittelabführleitung 17 ist am höchsten Punkt des Kreislaufes ein Ausgleichsbehälter 22 zum Ausgelich der Volumenänderung der Kühlflüssigkeit angeordnet, und vor der Kühlmittelpumpe 23 befindet sich ein Ein- und Nachfüllbehälter 24 für das Kühlmittel. Der Wabenkühler 16 ist luftgekühlt und mit einem regelbaren Kühlgebläse 25 ausgestattet.In the coolant discharge line 17, an expansion tank 22 is arranged at the highest point of the circuit to compensate for the change in volume of the coolant, and in front of the coolant pump 23 there is a fill and refill tank 24 for the coolant. The honeycomb cooler 16 is air-cooled and equipped with an adjustable cooling fan 25.

In Fig. 2 ist im Schnitt und in vergrösserter Darstellung das aussen am Schacht im Umlaufkanal 11 angeordnete Fördergebläse 12, insbesondere die Gebläsewelle 26 und das Gebläserad 27, dargestellt. Sowohl die Gebläsewelle 26 wie auch das Gebläserad 27 sind hohl ausgebildet. In der Gebläsehohlwelle 26 ist mit Abstand zur Hohlwelle selbst koaxial ein Hohlzylinder 28 angeordnet, wobei durch den entstehenden äusseren Ringraum 32 das Kühlmittel zugeführt und durch den Hohlzylinder 28 abgeführt wird. Der Kühlmittelringraum wie auch der Hohlzylinder stehen über einen ortsfesten Verteilerkopf 29 mit den ortsfesten Kühlmittelleitungen 15 und 17 in Verbindung, die ihrerseits mit dem luftdurchströmten Wabenkühler 16 in Fig. 1 einen geschlossenen Kühlmittelkreislauf bilden. Der Verteilerkopf 29 ist von einem an sich bekannten Leckagegehäuse umgeben.2 shows, in section and in an enlarged view, the conveying fan 12 arranged on the outside of the shaft in the circulation channel 11, in particular the fan shaft 26 and the fan wheel 27. Both the fan shaft 26 and the fan wheel 27 are hollow. A hollow cylinder 28 is arranged coaxially in the hollow blower shaft 26 at a distance from the hollow shaft itself, the coolant being supplied through the resulting outer annular space 32 and being discharged through the hollow cylinder 28. The coolant annulus as well as the hollow cylinder are connected via a stationary distributor head 29 to the stationary coolant lines 15 and 17, which in turn form a closed coolant circuit with the honeycomb cooler 16 through which air flows. The distributor head 29 is surrounded by a leakage housing known per se.

In dem ebenfalls hohl ausgebildeten Gebläserad 27 sind am äusseren Ende einer jeden Radschaufel 30 mäanderbandförmig verlaufende Leitbleche 31 angeordnet, denen aus dem Ringraum 32 der Gebläsewelle 26 das Kühlmittel über eine im Gebläserad angeordnete Leitung 33 zugeführt wird. Der Innenraum des Gebläsehohlrades 27 steht mit dem Hohlzylinder 28 über eine Verbindungsleitung 34 in Verbindung, die in der Radnabe 35 des Gebläserades 27 angeordnet sind.In the likewise hollow-shaped fan wheel 27, guide plates 31 are arranged at the outer end of each wheel blade 30 and meandering band-shaped, to which the coolant is supplied from the annular space 32 of the fan shaft 26 via a line 33 arranged in the fan wheel. The interior of the blower ring gear 27 is connected to the hollow cylinder 28 via a connecting line 34 which are arranged in the wheel hub 35 of the blower wheel 27.

Im Betrieb des oben beschriebenen querstrombeheizten Schachtofens mit gekühltem Gebläse zur Erzeugung eines geschlossenen Heissgasumlaufes in der jeweiligen Brennzone B strömen die in der Brennkammer 8 erzeugten Heissgase aus der Brennkammer in die Gaszufuhrkammer 3 und von dort durch die Gasdurchlassöffnungen 5 in der Schachtwandung 6 quer zur Durchsatzrichtung des Brenngutes in die dichtgeschüttete Brenngutschicht, treten auf der anderen Seite der Schüttung durch die Gasdurchlassöffnungen 5 in die Gasabzugskammer 4 ein und werden dort gesammelt. Aus der Gasabzugskammer 4 wird das Heissgas über die Abzugsöffnung 10 in den Umlaufkanal 11 mittels des Fördergebläses 12 gesaugt, welches damit unmittelbar in einem Heissgasstrom von etwa 800°C bis 1200°C liegt. Das Fördergebläse 12 leitet das Heissgas der Brennkammer 8 zu, in die über die Brenneinrichtung 9 Brennstoffe eingeführt werden, die dort in der mit vorgewärmter Frischluft sauerstoffangereicherten Atmosphäre ausbrennen. Auf diese Weise wird dem Heissgaskreislauf in jeder Brennzone B die für die mehrfache Umwälzung der Heissgase in der Brennzone erforderliche kinetische Energie zugeführt, wobei mit dem Gebläse innerhalb einer jeden Brennzone ein genau einstellbares Druckgefälle von mindestens 350 mm/WS ermöglicht wird. Hierdurch wird eine intensive Gasumwälzung mit hohem Durchsatzvolumen erzeugt, so dass dem in der Brennzone befindlichen Brenngut auch bei hohem Brenngutdurchsatz immer die Wärmemenge zugeführt werden kann, die für einen optimalen Brand erforderlich ist, so dass auch Feinststeine gebrannt werden können.In the operation of the cross-flow-heated shaft furnace described above with a cooled fan for generating a closed hot gas circulation in the respective combustion zone B, the hot gases generated in the combustion chamber 8 flow from the combustion chamber into the gas supply chamber 3 and from there through the gas passage openings 5 in the shaft wall 6 transversely to the throughput direction of the Fired goods enter the densely packed fired goods layer, enter the gas discharge chamber 4 on the other side of the bed through the gas passage openings 5 and are collected there. The hot gas is sucked out of the gas discharge chamber 4 via the discharge opening 10 into the circulation channel 11 by means of the delivery fan 12, which is thus directly in a hot gas flow of approximately 800 ° C. to 1200 ° C. The conveying fan 12 feeds the hot gas to the combustion chamber 8, into which fuels are introduced via the combustion device 9 and burn out there in the atmosphere enriched with preheated fresh air. In this way, the hot gas circuit in each combustion zone B is supplied with the kinetic energy required for the multiple circulation of the hot gases in the combustion zone, the fan making it possible to set a precisely adjustable pressure drop of at least 350 mm / WS within each combustion zone. This produces an intensive gas circulation with a high throughput volume, so that the amount of heat that is required for an optimal firing can always be added to the firing material in the firing zone, even with a high firing material throughput, so that even very fine stones can be fired.

Um zu verhindern, dass die Gase den Schacht 2 in vertikaler Richtung aufwärts durchströmen, sind zwischen jeder Brennzone Bl/B2 Dichtzonen angeordnet, die ein Abströmen der Heissgase in die darüberliegende Brennzone bzw. Vorwärmzone verhindern. Das aus der Brennzone in die Kühlzone K absinkende Brenngut wird in dieser durch zugeführte Kühlluft 36 auf entsprechende Weiterverarbeitungstemperatur gekühlt und über nicht näher dargestellte Abzugsorgane weiter verarbeitet. Die in der Kühlzone aufgeheizte Kühlluft gibt die vom Brenngut aufgenommene Wärmemenge an die Brennkammer 8 als Verbrennungsluft ab.In order to prevent the gases flowing through the shaft 2 in the vertical direction upwards, two sealing zones are arranged between each combustion zone B 1 / B and prevent the hot gases from flowing out into the overlying combustion zone or preheating zone. The combustible material that descends from the combustion zone into the cooling zone K is cooled to the appropriate further processing temperature in the cooling air 36 and is further processed via extraction elements (not shown). The cooling air heated in the cooling zone releases the amount of heat absorbed by the material to be burned into the combustion chamber 8 as combustion air.

Ein Teil der in den Brennzonen B, und B2 erzeugten Heissgase wird aus den Brennzonen abgezweigt und über nicht näher dargestellte im Ofen 1 verlaufende Leitungen dem stückigen Gut in der Vorwärmzone zu dessen Vorwärmung zugeleitet.A portion of the hot gases generated in the combustion zones B and B 2 is branched off from the combustion zones and is fed to the lumpy material in the preheating zone for preheating it via lines not shown in the furnace 1 headed.

Das Fördergebläse 12 steht über den Verteilerkopf 29 mit einem geschlossenen Kühlkreislauf 14 in Verbindung, der wie oben beschrieben ausgebildet ist. Die Kühlung des Gebläses mit der Kühlvorrichtung erfolgt mittels eines temperaturbeständigen Wärmeträgeröls, insbesondere eines Silikonöls, welches auf eine Arbeitstemperatur zwischen 200 und 220°C eingeregelt wird, wozu in den ortsfesten Kühlmittelleitungen der Kühlvorrichtung 14 entsprechende Regeleinrichtungen, wie Druckwächter 18, Thermostatventil 19 und Strömungsmesser 20 angeordnet sind. Hierdurch ist es möglich, sämtliche im Heissgasstrom (etwa 800°C bis 1200°C) des Umlaufkanals 11 liegende Gebläseteile so zu kühlen, dass deren Temperatur mit Sicherheit unter der thermischen Maximalbeanspruchung des eingesetzten Materials liegen. Zum anderen werden durch die auf maximal 240°C aufgeheizten im Heissgasstrom liegenden Gebläseteile, die aus dem Brenngut verflüchtigten, schädlichen und zu Anbackungen neigenden Alkali- oder Schwefelverbindungen schockartig abgekühlt und aus den Heissgasen auskristalliert, so dass sich am Gebläse bzw. an den Gebläseschaufeln keine Ansätze bilden können, die entweder die Durchsatzcharakteristik des Gebläses negativ beeinflussen oder aber zu erhöhten Lagerbelastungen am Gebläse führen. Durch den Einsatz des mit einem Wärmeträgeröl im geschlossenen Kreislauf gekühlten Gebläses unmittelbar im Heissgasumlauf der Brennzone eines querstrombeheizten Schachtofens ist es möglich, in jeder Brennzone ein so hohes Druckgefälle zu erzeugen und damit eine so hohe kinetische Energie für den Heissgasumlauf bereitzustellen, dass Ofeneinheiten mit dem doppelten Durchsatz gegenüber mit Injektoren ausgestatteten Querstromöfen möglich sind.The conveying fan 12 is connected via the distributor head 29 to a closed cooling circuit 14 which is designed as described above. The cooling of the blower with the cooling device takes place by means of a temperature-resistant heat transfer oil, in particular a silicone oil, which is regulated to a working temperature between 200 and 220 ° C, for which purpose corresponding control devices, such as pressure switch 18, thermostatic valve 19 and flow meter 20, are located in the fixed coolant lines of the cooling device are arranged. This makes it possible to cool all the blower parts in the hot gas stream (about 800 ° C. to 1200 ° C.) of the circulation channel 11 in such a way that their temperature is definitely below the maximum thermal stress of the material used. On the other hand, the blower parts in the hot gas stream, heated to a maximum of 240 ° C, shock-cool the alkali or sulfur compounds that volatilize from the fired material and tend to cake and crystallize out of the hot gases, so that none on the blower or blower blades Can form approaches that either negatively affect the throughput characteristics of the blower or lead to increased bearing loads on the blower. By using the blower, which is cooled with a heat transfer oil in a closed circuit, directly in the hot gas circulation of the combustion zone of a cross-flow-heated shaft furnace, it is possible to generate such a high pressure drop in each combustion zone and thus to provide such a high kinetic energy for the hot gas circulation that furnace units with double Throughput compared to crossflow furnaces equipped with injectors are possible.

Die vorliegende Erfindung, die nur für querstrombeheizte Schachtöfen zum Brennen oder Sintern von Kalkstein, Dolomit oder Magnesit beschrieben ist, lässt sich überall dort anwenden, wo direkt in einem Heissgasstrom Gebläse eingesetzt werden müssen, um die für die Gasförderung erforderliche kinetische Energie zu erzeugen.The present invention, which is only described for cross-flow heated shaft furnaces for burning or sintering limestone, dolomite or magnesite, can be used wherever blowers must be used directly in a hot gas stream in order to generate the kinetic energy required for gas production.

Claims (16)

1. A furnace for heat-treating material either in lumps or fine-grain form, more particularly a shaft furnace, a rotary hearth-type furnace etc. for roasting or sintering limestone, dolomite or magnesite, in which furnace the material to be roasted passes through a preheating region (V), a roasting region (B) and a cooling region (K), and the roasting region (B) has a gas supply and a gas outlet chamber (3, 4), a roasting device (9) and a gas driving device (12) for producing a circulation of hot gas, characterized in that the gas driving device (12), which is arranged preferably between the gas outlet chamber (4) and the roasting device (9) is a conveyor fan acted upon by a cooling medium.
2. A furnace according to Claim 1 which is a shaft furnace (1) heated by a cross current and having at least one roasting region (B) and a gas supply and gas outlet chamber (3,4) associated with each roasting region and arranged laterally on the shaft, the furnace being characterized in that the cooled gas conveyor fan (12) is arranged in the hot circulation channel (11) between the gas outlet chamber (4) and the roasting chamber (8).
3. A furnace according to claim 1 or 2, characterized in that the conveyor fan (12) is arranged on the outside of the shaft (2) and is connected to a cooling device (14) having an enclosed supply of cooling medium.
4. A furnace according to Claim 1, 2 or 3, characterized in that the re-cooling device (16) of the fan cooling device (14) serves as a heat exchanger for the fuels introduced into the roasting chamber (8).
5.A furnace according to Claim 1, 2, 3 or 4, characterized in that the fan shaft (26) and/or the fan wheel (27) of the conveyor fan (12) are hollow and devices which supply the cooling medium, preferably pipes (32, 33), are arranged in the hollow shaft and/or in the hollow wheel.
6. A furnace according to any one of Claims 1 to 5, characterized in that the cooling medium pipes (32,33) of the fan shaft (26) are in connection with the fixed cooling medium pipes (15, 17) of the re- cooling device (16) via a fixed distributor head (29), the recooling device (16) preferably being formed as a honeycomb or tubular cooler through which air flows.
7. A furnace according to any one of Claims 1 to 6, characterized in that pressure monitoring devices (18), thermostats (19) and flowmeters (20) are arranged in the fixed cooling medium pipes (15,17).
8. A furnace according to any one of claims 1 to 7, characterized in that the cooling medium pipes (32) in the hollow fan shaft (26) are formed from a hollow cylinder (28) aligned coaxially at a spacing from the hollow shaft, the cooling means entering through the resultant outer annular chamber and leaving through the hollow cylinder.
9. A furnace according to any one of the preceding Claims, characterized in that the cooling medium pipes (33) in the fan wheel are preferably shaped like a meander belt at the outer end of one or more vanes of the wheel.
10. A furnace according to any one of the preceding Claims, characterized in that guide elements (31) for the cooling medium are arranged in the hollow fan wheel (27).
11. A furnace according to any one of the preceding Claims, characterized in that the hollow fan wheel (27) is in connection with the hollow cylinder (28) in the fan wheel (26) via connecting lines (34) in the wheel hub (35).
12. A furnace according to any one of Claims 1 to 11, characterized in that the cooling means is an organic or inorganic fluid which is resistant to high temperature and has a boiling point of more than 100°C.
13. A furnace according to Claim 12, characterized in that a heat carrying oil, more particularly a silicone oil, is used as the cooling fluid.
14. A furnace according to Claim 12 or 13, characterized in that the operating temperature of the cooling fluid is between 100°C and 270°C, but more particularly between 200°C and 220 °C.
15. A furnace according to Claim 12, 13 or 14, characterized in that the cooling fluid is recooled by air in the cooler (16).
16. A furnace according to any one of Claims 12 to 15, characterized in that the cooling fluid circuit (14) is monitored by pressure monitoring devices (18), thermostats (19) and flowmeters (20).
EP79102695A 1978-08-18 1979-07-30 Furnace for the thermal treatment of granular or fine sized material Expired EP0008667B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT79102695T ATE67T1 (en) 1978-08-18 1979-07-30 FURNACE FOR THE HEAT TREATMENT OF LITTLE TO FINE GRAIN MATERIAL.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2836162 1978-08-18
DE19782836162 DE2836162A1 (en) 1978-08-18 1978-08-18 OVEN FOR HEAT TREATMENT FROM MOST PIECE TO FINE GRAIN

Publications (2)

Publication Number Publication Date
EP0008667A1 EP0008667A1 (en) 1980-03-19
EP0008667B1 true EP0008667B1 (en) 1981-05-13

Family

ID=6047346

Family Applications (1)

Application Number Title Priority Date Filing Date
EP79102695A Expired EP0008667B1 (en) 1978-08-18 1979-07-30 Furnace for the thermal treatment of granular or fine sized material

Country Status (6)

Country Link
US (1) US4252521A (en)
EP (1) EP0008667B1 (en)
JP (1) JPS5531298A (en)
AT (1) ATE67T1 (en)
DE (2) DE2836162A1 (en)
SU (1) SU932999A3 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3209836A1 (en) * 1982-03-18 1983-09-29 Dolomitwerke GmbH, 5603 Wülfrath METHOD FOR PRODUCING SINTERDOLOMITE IN A SHAFT OVEN AND SHAFT OVEN FOR IMPLEMENTING THE METHOD
JPH0543227Y2 (en) * 1987-12-21 1993-10-29
CN101745783B (en) * 2009-12-14 2011-07-20 成都天保重型装备股份有限公司 Manufacturing technology of furnace body of calcining furnace
CN102092968B (en) * 2011-01-07 2012-06-27 重庆京庆重型机械股份有限公司 Lime smoldering furnace
CN102627418B (en) * 2012-04-26 2013-08-21 石家庄新华能源环保科技股份有限公司 Compound lime kiln

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1653217A (en) * 1927-12-20 Combustion turbine
US1713237A (en) * 1928-01-11 1929-05-14 Pacific Abrasive Supply Compan Drier
US2345067A (en) * 1939-08-17 1944-03-28 Osann Bernhard Method of and apparatus for operating shaft furnaces for roasting and the like
US2369795A (en) * 1941-11-17 1945-02-20 Andre P E Planiol Gaseous fluid turbine or the like
US2393963A (en) * 1944-09-22 1946-02-05 Adolph L Berger Turbine wheel
US2455313A (en) * 1945-02-19 1948-11-30 Irving B Osofsky Heat exchanging airplane propeller
US2778601A (en) * 1951-05-28 1957-01-22 Ernst R G Eckert Fluid cooled turbine blade construction
US2883151A (en) * 1954-01-26 1959-04-21 Curtiss Wright Corp Turbine cooling system
US2948521A (en) * 1956-07-14 1960-08-09 Roechlingsche Eisen & Stahl Process and apparatus for heating a cross stream shaft furnace in view of heating solid materials, particularly for the calcination of limestone
DE1034090B (en) * 1956-07-14 1958-07-10 Roechlingsche Eisen & Stahl Cross-flow heated shaft furnace for heating bulk material, especially for burning limestone
US2952441A (en) * 1956-12-10 1960-09-13 Int Harvester Co Cooling construction for gas turbine blades
DE1241041B (en) * 1961-12-27 1967-05-24 Kloeckner Humboldt Deutz Ag Cross-flow furnace for burning lime, dolomite or the like.
DE1197798B (en) * 1963-10-12 1965-07-29 Sofim Saar Saarofenbau Fuer In Process for burning limestone and device for carrying out the process
US3311344A (en) * 1964-12-08 1967-03-28 John V Yost Turbine wheel
FR1440786A (en) * 1965-04-21 1966-06-03 Sofim Saar Saarofenbau Fuer In Method for firing limestone and device for carrying out this process
GB1187251A (en) * 1967-09-08 1970-04-08 Gas Council Improvements in or relating to Cooling Systems for Rotary Machines
US3544096A (en) * 1968-05-22 1970-12-01 Kloeckner Humboldt Deutz Ag Cross-current blast furnace
US3936220A (en) * 1974-08-26 1976-02-03 Controls Southeast, Inc. Jacket construction for fluid-circulating pumps

Also Published As

Publication number Publication date
ATE67T1 (en) 1981-05-15
SU932999A3 (en) 1982-05-30
US4252521A (en) 1981-02-24
EP0008667A1 (en) 1980-03-19
JPS5531298A (en) 1980-03-05
DE2836162A1 (en) 1980-02-28
DE2960351D1 (en) 1981-08-20

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