Coke oven plant for producing coke, method for operating a coke oven plant and use thereof

Abstract

The invention relates to a coke oven device (10) for producing coke, comprising a plurality of double heating flues (13) with heating pipes, the heating pipes being bounded in pairs by partitions (14) and separated by two mutually opposite parallel brick masonry walls (15), wherein at least one inlet from the following group is arranged in the lower region on the base (5.4) of the corresponding heating pipe: a coke oven gas inlet (18), a combustion air inlet (16), a mixed gas inlet (17); wherein, on the corresponding base (5.4), the combustion air inlet (16) and the mixed gas inlet (17) are arranged. The ratio (y1:y2) of the distance (y1) between the facing edges of the opening (16) and the mixed gas inlet (17) to the distance (y2) of the inner edge of the partition (14) is at least 10%, wherein the distance (y1) between the facing edges of the combustion air inlet (16) and the mixed gas inlet (17) is at least 50 mm, wherein at least one of the combustion air inlet and the mixed gas inlet (16, 17) is eccentrically arranged at an x ​​distance greater than 0.7 times the absolute x length of the heating duct between the opposite parallel brickwork walls (15). The invention also relates to a corresponding method.

Description

Technical Field

[0001] The present invention relates to a method for minimizing NO x Device and method for producing coke by exhaust gas and corresponding uses. Background Art

[0002] The demand for coke ovens remains high worldwide and is expected to remain high in the future, as is described, for example, in the following publications: K. WESSIEPE et al.: Optimization of Combustion and Reduction of NOx-Formation at Coke Chambers… Coke Making International; 9, 2; 42-53; Verlag Stahleisen mbH; 1997. Despite increasingly stringent environmental standards, even today several hundred new coke ovens are built and put into operation every year. It is estimated that in Asia alone the number of new coke ovens built each year is well over 1,000. However, it is now well known not only among engineers but also in society that the production of energy with the aid of coke ovens is not particularly environmentally friendly. Therefore, many parties are imposing increasingly stringent requirements on the construction of new coke ovens or even on the operation of existing coke ovens in order to minimize emissions, especially with regard to nitrogen oxides (NO x ). In this regard, there are many attempts to increase the efficiency of coking. The planning and construction of coke ovens must be carried out over a long period of time. Especially with regard to the long operating time or life span required for coke ovens, it is important to know which environmental improvements can be achieved in connection with coke ovens in the coming years. However, given the engineering and structural complexity of coke ovens, the targeted pursuit of individual optimization measures is not a trivial matter; rather, the individual optimization measures must be compared and weighed against each other in an overall approach, in which there are many dependencies.

[0003] In recent years, there have been increasing reports from conferences and journals that not only the local environmental authorities in their respective countries, but also customers have imposed very stringent requirements in terms of reducing the environmental load from flue gas emissions, or such tightening is expected in the near future. With regard to these flue gas emissions, one of the main causes that has been shown to be the generation of NO in the vertical, flue gas-conducting heating ducts of coke ovens is x of heat formation.

[0004] The limit emission values ​​permitted in 2018 or still permitted for existing installations can be stipulated as follows, especially for the European region: 500 mg / Nm³, which corresponds to about 250 ppm at 5% oxygen O2. However, this has been the limit value for many years and in the near future many countries may further reduce it. Therefore, there is an interest in significantly falling below this limit value in the very near future through technical measures.

[0005] Nitrogen oxides are released in particular by flue gases, which are produced in particular during the combustion of coke oven gases, in particular above a nozzle brick temperature of about 1250° C. (i.e. the temperature in the exhaust gas conduction heating duct on the base); the term used in this case is NO x As the temperature continues to rise, NO x The heat formation of NO is stimulated or further favored in an exponential manner, so that the emission of nitrogen oxides depends largely on the thermal operating conditions of the coke oven under the corresponding load state. Therefore, it is also known that, in particular in the vertical flue gas conducting heating ducts of the coke oven, the NO emission can be influenced by establishing and controlled maintaining a defined temperature range. x Emissions. Therefore, the furnace operator aims, or is forced by environmental requirements, to keep the temperature in the exhaust gas conducting heating duct as low as possible and, more particularly, not to allow said temperature to rise above 1250°C. However, in plant practice, higher process temperatures ranging from 1250°C to 1320°C have been established worldwide, which is a compromise for plant operation, which is not only environmental but also economical.

[0006] Therefore, in NO x The plant regime optimized in terms of emissions must be adapted to the reduced (relatively low) temperature levels in the heating duct. However, this is associated with a reduction in the coking performance and therefore automatically with a loss in coke production. For example, if the permitted operating temperature is higher, only about 95 to 98 furnaces need to be built instead of 100 furnaces, which is equivalent to a 2% to 5% saving in equipment (lower investment volume, up to 5% reduction in equipment costs, involving an investment volume of, for example, 100 million to 800 million euros).

[0007] In view of these uneconomical performance losses, attempts to reduce NOx are made by avoiding local temperature peaks in the heating flue and / or by permanently maintaining lower temperature levels during coking. x There is very little willingness to release NOx. Instead, high NOx is permitted where legally permitted. x Nevertheless, furnace operators know that if heat energy input can be maintained at a constant level with relatively modest temperature reductions, this is essential for minimizing NO emissions. x The emissions are beneficial while providing comparable output.

[0008] Coke ovens can be subdivided, in particular with respect to the direction of coke injection, into vertical and horizontal chamber ovens. In horizontal chamber ovens, coking is carried out in batches and then the coke is injected in the horizontal direction (batch operation). In contrast, in vertical chamber ovens, coal is fed and discharged continuously in the vertical direction (continuous operation). The present invention relates in particular to horizontal chamber ovens.

[0009] The coke ovens can be heated optionally by a gas mixture produced from blast furnace gas and coke oven gas or by pure coke oven gas (coke oven gas heating is usually less than 10% of the annual operating cycle). Due to the high proportion of hydrogen and carbon monoxide and the resulting high flame temperature, the flue gases produced by the combustion of coke oven gas are especially loaded with high NO x

[0010] For this reason, many measures to date have been aimed primarily at reducing NO x

[0011] Emissions, in particular in the case of heating with coke oven gases. The following table gives an overview of the elemental distribution (in % by volume) of the corresponding type of gas, derived from average values ​​obtained over the years, in particular from the owner of the intellectual property rights of the present invention:

[0012]

[0013] Trace elements in three gas types: e.g. ammonia, noble gases;

[0014] Blast furnace gas is produced during iron ore smelting operations in a blast furnace and due to its typically low heat content (2700 to 3800 kJ / Nm 3 ), also called "low calorific" gas. Blast furnace gas is cheaper. Coke oven gas is produced during the coking process in coke ovens and has a high heat content (between 15900 and 19500 KJ / Nm 3 The lower calorific value of coke oven gas is between 1.5 and 2.5 (lower calorific value between 1.5 and 2.5). Therefore, it is also called "rich gas". Coke oven gas is relatively expensive.

[0015] For economic reasons, these two types of gases are usually used in practice so that they are premixed in a ratio of 87 to 97% by volume of blast furnace gas and 3 to 13% of coke oven gas and fed to the coke oven for combustion. This mixed gas is usually used as a heating gas in the coke oven for more than 90% of the year. Other types of gases that are occasionally mixed as alternative components of the starting gas (blast furnace gas, coke oven gas) are known by the terms "converter gas" or "generator gas" (the resulting gas mixture is usually called "coke oven mixed gas"). "Converter gas" usually comes from the steelmaking industry. "Generator gas" is produced in many industrial sectors, usually in coal processing operations. The present invention mainly relates to the use of a more narrowly defined mixed gas, in other words, a mixed gas that does not contain a fraction of "converter gas" or "generator gas" as defined above.

[0016] With reference to the table above, hydrogen is considered to be the component whose combustion is associated with the highest local flame temperature and therefore with the highest thermal formation of nitrogen oxides. Coke oven gas has a much larger hydrogen fraction than blast furnace gas. Therefore, the heating of coke oven gas causes particularly great difficulties in plant operation with regard to emission limit values.

[0017] It is worth mentioning that there are also coking plants with so-called "gas-rich furnaces" which, especially due to their isolated geographical location, cannot be connected to a blast furnace and (have to) utilize the gases produced in the coke oven during the pyrolysis of the coal itself for heating 100% of the operating time; in this case, the gases are usually returned to the furnace after appropriate removal of impurities or valuable compounds in so-called secondary recovery plants. However, these furnaces are not designed for standard "mixed gas heating".

[0018] The furnace chamber of the above-mentioned coke ovens typically (as of 2018) has a height in the range of 4 to 8.5 m. The preferred height of the furnace chamber and / or the heating duct is also determined by the operating mode. This height influences the pressure difference established in the heating duct. If a large pressure difference is required, a large height must be selected. It can be assumed that the temperature remains as constant as possible over the entire height of the furnace chamber, because only in this case is it possible to establish an efficient operating state without excessive increase of NO x The temperature gradient should be as much less than 40K or 40°C as possible, especially at furnace temperatures in the range of 1000 to 1100°C. This smaller temperature gradient is also beneficial for optimizing the coke quality. A maximum temperature significantly above the average temperature will promote NO x When the temperature distribution is very uniform and when the temperature in the entire furnace chamber is kept just below x The temperature of the heat formation or the index favors NO x The heat formation temperature of the coke oven can be high output and NO x The engine operates at a particularly optimal compromise between low emissions and

[0019] Design changes in the construction of coke ovens entail high costs and complexity. The effects of individual optimization measures must be as predictable as possible in a cost-effective manner before these measures can be implemented in the construction of the oven. Simulations of the operating state are a useful tool that allows a better estimation of the effects of individual optimization measures. However, coke ovens are relatively complex plants, so even purely computer-aided simulations involve a corresponding degree of costs and complexity. For example, a new building with a new gas route can mean several weeks of computational effort per calculation (even with the technical possibilities of 2018), which means that the workload even for purely electronic / computer-aided simulations can amount to several years (e.g. in the case of more than a hundred changes being required). Therefore, not only must new measures on a plant scale be tested in the finished coke oven with limited possibilities, but even simple construction measures, solely for cost reasons, must first be examined in multiple aspects before the measure can be investigated in more detail by simulation. As a result, construction changes to existing oven designs are only proposed, tested and experimentally verified in a very mild, conservative manner.

[0020] The measures that have been tested so far directly on the coke oven or on its construction and are also effective in the case of output-optimized operation are usually internal recirculation of flue gas, driven by pressure differences or differences in temperature and density, from the bottom into the upward-flowing heating duct (internal circulation route of the partial volume flow of the flue gas, called circulation flow), and / or staging of the combustion air, in other words, the introduction of the combustion gas into the heating duct from partitions or binder walls at different vertical positions. The staging of the combustion air is carried out in particular in relation to the following criteria: the maximum gas collection space temperature in the adjacent furnace chamber above the coal charge must / should be, for example, below 820° C.; the ceiling surface temperature must be as low as possible or equal to 65° C.; the temperature difference inside the furnace chamber wall must be, for example, below or equal to 40 K, in particular between the vertical positions of 500 mm above the furnace floor / burner level and 500 mm below the upper edge of the furnace chamber.

[0021] Here, the circulation flow path is usually realized in the so-called double heating flues (partially only at one end of the heating pipe, or in a completely circumferential circular manner). Adjacent pairs of heating flues or heating pipes (especially in the vertical direction) are coupled to each other, wherein the gas from the burning heating pipe is returned to the unburned heating pipe only at the upper / lower reversal point or at both the top and the bottom. In the case of a horizontal cavity furnace, there can be about 24 to 48 heating pipes and therefore about 12 to 24 double pairs of heating pipes, which are connected in series with each other when viewed in the injection direction. The optionally achievable circulation flow can be generated autonomously due to the pressure difference, and is therefore based only on the temperature and density differences in the two corresponding double heating flues, and therefore without additional active fluid regulation or support. In other words, the variation of the construction design is also limited by the sensitive (thermal) balance, which must be achieved by the pressure difference.

[0022] On an industrial scale, optimization of circulation flow paths, including in particular for the purpose of uniform heat distribution, was started as early as the 1920s. Since the 1970s, the optimization of circulation flow paths for NO x The impact of emissions has been studied more systematically / in-depth.

[0023] In paired heating ducts (double heating flues), it is necessary to control or limit the average nozzle brick temperature, more specifically, the nozzle brick temperature must be kept at a moderate level (for example, nozzle brick temperature of 1240 to 1300°C) by reducing the local flame temperature (above 2000°C for rich gas heating and below 2000°C for mixed gas heating). The effect is to control NO x In the case of mixed gas heating, the flame temperature is, for example, in the range of 1500 to 1700°C, more particularly at about 1600°C.

[0024] For example, the following arrangement (vertical position) of the lower channel between the paired heating pipes can be identified: between 0 mm (ie directly at the level of the burner plane) and 300 mm above the burner plane. In this case, the cross-sectional area of ​​the channel is generally determined by a layer height (or a layer width) of about 110 mm to 150 mm. When necessary, the lower channel arranged on the base can be closed by rollers that can be rolled in front of the channel on the burner plane. The channel is advantageously realized by a gap in the wall layer (a gap or a non-existent brick). In the case where the present description refers to a single channel, it can also be a pair of channels arranged in the same vertical position.

[0025] Here, the burner plane is understood to be the vertical level at which the inlet is constructed to open into the heating duct and at which a height variation is achieved within certain limits, optionally due to an extended inlet nozzle (more particularly up to 1000 mm above the burner plane). Different from this are furnace types which are designated as stepped gas furnaces and in which at least one inlet is provided only at a height above the burner plane which is much higher than 1000 mm.

[0026] The vertical position of the lower channel or a pair of lower channels can also be arranged at a height of 1000 mm above the burner plane.

[0027] The vertical position of the lower channel or the pair of lower channels may also be arranged below the burner plane, more specifically up to 500 mm below the burner plane.

[0028] The partial volume flow of flue gas (usually returned to the fired heating duct) amounts, for example, in the case of rich gas heating, to 30% to 45% of the total flue gas volume generated in the upwardly traversing heating duct. An example of such an arrangement of a double heating flue with a circulating flow is the so-called Combifame heating system which has been in existence since the late 1980s. In this case, there is a combination of an air phase and a circulating flow path. Previously, until the mid-1980s, there was either only an air phase (Otto system) or only a circulating flow path (Koppers system).

[0029] As mentioned above, the combustion can also be staged by the gas or air in at least one vertical position above the burner plane (base) entering the corresponding heating flue via at least one staged air duct, or the exhaust gas being discharged accordingly. The staged combustion can be combined with a circulating flow route.

[0030] If special attention is paid to measures directly aimed at the coke oven, in other words, in particular measures for thermal optimization through optimized patterns of media paths, the structural design of the coke oven and, in connection with this, the stability of the coke oven are crucial, in particular the structural design of the individual walls (brick masonry walls, partitions) of the corresponding oven chamber and the corresponding heating flue. Small measures in the structural design may have a large impact on the temperature balance and the coking process. However, any measures may also have very unfavorable side effects that are to be avoided, for example, on the statics of the heating wall, the flow resistance or the temperature curve and flow rate ultimately established. Therefore, it can be expected that changes to the construction described in more detail below can be implemented only within a narrow tolerance range. In particular, one of the tasks facing the person skilled in the art is to make any risk of weakening the heating wall components non-existent by means of new measures. The reason is that, depending on the operating state, high lateral forces can act on any wall. For example, after about 75% of the carbonization time, a high lateral internal pressure (advance pressure of the coal charge) is formed, in particular on the parallel brick masonry walls, wherein the maximum pressure is at a height of about 1 m above the burner plane, and this advance pressure may even lead to expansion of the joints in the masonry of the partition to the furnace chamber, and may also affect the occurrence of undesirable bypass flows between the individual heating flues and the (adjacent) furnace chambers (with the migration of coke oven gases and the associated formation of CO). This also disrupts the balance of the gas mixture; in particular, the amount of air available for the additional amount of gas burned in the heating duct is insufficient. In addition, different filling times (for example, offset by several hours from each other) also lead to differences in the lateral forces in the corresponding walls in adjacent furnace chambers. Therefore, in the context of the above-mentioned necessary measures for reducing emissions, the stability of the furnace is also highly prioritized. High stability is usually achieved by the tongue-and-groove arrangement of the bricks. This simultaneously highly flexible construction mode is also preferred for sealing in order to avoid bypass flows and premature combustion. A person skilled in the art has no reason to deviate from a solid construction combining maximum flexibility and maximum stability without specific reasons.

[0031] In the case of a group with a plurality of furnace chambers, for example, at least 15 furnace chambers up to a maximum of 90 furnace chambers, the furnace chambers are defined by a brick-laid wall from a gas-conducting heating duct, in particular at the relatively narrow end side of the respective duct, more particularly by two opposite brick-laid walls extending along the entire respective furnace chamber. In this case, the individual heating ducts are separated from each other by so-called bonding walls (partitions), which extend between the brick-laid walls, in particular orthogonally to the two brick-laid walls. The bonding wall separates the two ducts from each other, or the two bonding walls separate a pair of double heating flues from another adjacent pair of double heating flues. Thus, the respective heating duct is defined by two brick-laid wall portions and two bonding walls. In the injection direction (depth y), the respective heating duct has, for example, a length or depth (center to center) of approximately 400 to 550 mm. The brick-laid wall thickness here is, for example, in the range of 80 to 120 mm. Here, the thickness of the bonding wall is, for example, in the range of 120 to 150 mm.

[0032] The term "bonded wall" is established within the usual grammatical usage. In the present description, the term is used synonymously with the term "partition" in order to make it particularly clear that brick-laid walls and bonded walls / partitions can be produced in the same construction mode, in particular by means of bricks which are laid adjacent to one another in rows at their narrow sides, respectively. The "brick-laid walls" of a horizontal chamber furnace can also be described as longitudinal walls arranged longitudinally in the injection direction, and the "bonded walls" can also be described as transverse dividing walls (partitions) arranged transversely to the injection direction.

[0033] On the lower side of the respective heating ducts, combustion air openings and mixed gas openings are provided, the functions of which can be selected or set depending on the type of heating (mixed gas heating or coke oven gas heating). The coke oven gas openings lead into the lower heating duct. In the case of a circulation flow path, a pair of heating ducts are coupled to each other via exhaust gas recirculation openings provided on the lower side of the furnace chamber, respectively, to form a double heating flue with a circulation flow path. The volume flow through the exhaust gas recirculation openings can be selectively adjusted, more particularly by adjusting rollers, which are arranged on the base in the burner plane and can be moved there. In the bonding wall, stepped gas ducts are provided, which introduce combustion air (stepped gas) into the furnace chamber (air stage or bonding wall opening) in one or more vertical positions. Typical ratios of the volume flow introduced into the furnace chamber can be cited as follows: approximately 30% through the combustion air inlet on the base, approximately 30% through the mixed gas inlet on the base, and approximately 40% through at least one stepped gas inlet (bonding wall opening). The ratio may also be similarly set for exhausting gases from the furnace chamber depending on performance requirements.

[0034] A bypass flow in the manner of a differential heat exchanger is constructed above the exhaust gas reversal point (recirculation channel) to adapt the coking parameters. The bypass flow can be separated from the heating duct by a wall, more particularly a horizontal wall or a ceiling, which contains a channel that can be covered by means of sliding bricks, for example, or whose cross section can be adjusted by means of sliding bricks.

[0035] The above-mentioned publication by K.WESSIEPE also pays special attention to measures for furnaces with double heating flues and already found in the 1990s that a so-called circulating flow arrangement can provide the lowest possible NO x Advantages in terms of concentration.

[0036] As prior art, patent specifications DE 34 43 976 C2 and DE 38 12 558 C2 may be cited illustratively, which discuss the aspects of optimum circulation flow rates and suitable vertical positions for the staged introduction of combustion air, in particular using a Koppers circulating flow furnace as an example. Therein, it is also mentioned that the recirculation of flue gases at a vertical position in the region of the heating flue floor allows the temperature in the corresponding heating flue to be lowered, thereby having the effect of reducing NO x The effect of emissions.

[0037] Publication specification CN 107033926 A from August 2017 describes an arrangement with a double heating flue with a staged introduction of the combustion air and with circulating flow openings which are arranged transversely on both sides of the staged air duct.

[0038] In order to be able to influence the heat distribution in the coke oven, experiments have also been carried out with specific types of gas-conducting components or filling elements. For example, patent specification DE 39 16 728 C1 provides a heating space (heating flue) with an inner part in the form of a permeable honeycomb element or a mesh or a pebble bed, and specific types of flue gas paths are also considered to be partially advantageous. The problem in this case is to improve the flow conditions in the heating space, and it is also proposed to feed the combustion air at different vertical positions.

[0039] Experiments have also been conducted using specific coatings for effectively transferring or reflecting thermal energy from interior surfaces.

[0040] The above measures described directly on the coke oven or heating flue or in the heating flue can be described here as the main measures, which are aimed at counteracting the main NO in the heating flue. xFormation mechanism (more specifically, internal flue gas recirculation or circulating flow, staging of the combustion air). For all the above-mentioned measures, it must be noted that the furnaces described here are usually operated with autoignition (especially above 800°C), so that corresponding measures for cooling or reducing the gas temperature can only be carried out under strict boundary conditions or only within a narrow temperature range, especially in order to prevent the combustion from being extinguished.

[0041] Furthermore, so-called secondary measures have been tested, which can be carried out in subsequently connected plant components downstream of the coke oven, for example by using selected catalysts (SCR or DeNO x ) to reduce NO in the flue gas before it is evacuated to the atmosphere x The fraction, or already evacuated flue gas, is recirculated from the outside of the chimney to the coke oven. Regardless of how effective these downstream measures are, they are in many cases frustrated by extremely high costs (up to 50% of the total investment in the entire coke oven) or additional maintenance costs and complexity. These measures, while effective, are in many cases too costly.

[0042] Patent application DE 40 06 217 A1 may also be mentioned, which describes a combination of measures, including not only measures for a heat accumulator in the central part of the furnace, but also measures for an external circulation flow of the flue gases, with the aim of achieving a uniform heating state and low NO x emissions, even in the case of higher furnace chambers.

[0043] Furthermore, measures of a chemical, reactive nature are considered, such as the introduction of CH4 gas or the increase of the moisture content by the injection of water, or the feed of ammonia. However, water or steam cannot be injected at any arbitrary position in the furnace chamber, but only in the center of the central vertical position; moreover, such measures also have a negative effect on the (silicate) materials used. Increasing the regeneration preheating temperature of the gas and air is a measure that is currently considered to be exhausted and uneconomical.

[0044] In 2018, it seems inconceivable that the above requirements can be met in any way, especially through the above-mentioned major internal measures, either individually or cumulatively. x Reductions in emissions by a considerable factor, more particularly a factor of 2 to 5, appear to be unattainable, more particularly reductions to the range below 200 mg / Nm³ or below 100 mg / Nm³, or at least not achievable with reasonable cost and complexity and therefore not economical.

[0045] Despite the above-mentioned problems, the present invention relates to optimizing the coke oven by measures directly on the coke oven or in its structural design, more specifically by measures on an established heating system, which has at least one recirculation opening, in particular with a recirculation flow path, so that in particular in a performance-optimized operating mode the option of being able to operate the coke oven even completely without downstream plant components (dedicated to the reduction of NO x This could offer the promise of a huge potential for improvement, also be of great advantage to the furnace operator and therefore also offer a good chance for the technical concept to be implemented commercially.

[0046] The measures to date have been mainly aimed at reducing the disproportionately high NO formation in the case of coke oven gas heating, in other words, in the case of heating with pure coke oven gas (not with mixed gases) - in the case of heating with mixed gases, these measures may often be less effective. In the case of mixed gas heating, many of these measures may even have a negative impact on NO x However, coke plants are usually operated primarily with mixed gas heating; in applications estimated at more than 90% or during operating time estimated at more than 90%, mixed gas heating is the main heating method (e.g. coke oven gas heating only in emergency situations or during maintenance work). In theory, measures for coke oven gas heating must therefore be about ten times more effective than measures for mixed gas heating in order to be able to save the same total NO over the life of the oven. x Furthermore, many measures for coke oven gas heating have the disadvantage of increased pressure losses in the oven, with the result that the plant planning must include negative pressure sources with increased output.

[0047] Furthermore, newer measures for reducing disproportionately high NO formation have so far been mainly associated with coke oven gas heating. x The relevant optimization and interest in the design of the heating stack (especially for mixed gas heating methods) has so far received less attention in many cases. In this paper, of course, we can first consider the known main NO x Emission reduction technology. Summary of the invention

[0048] The object of the present invention is to provide a coke oven plant and a method for operating the coke oven plant, with which the NO x Emissions, especially NO used for heating of the gas mixture x emissions and can also be minimized in full-load operation in the case of existing or new plants, where the coke oven plant enables advantageously low NO xThe object is to provide a coke oven plant and a method for operating the same which allow the reduction of NO by internal measures in the heating flue, more particularly only by internal primary measures. x emissions, in particular in the context of mixed gas heating. In particular for mixed gas heating, such measures preferably require only minimally greater pressure losses; in particular, any increase in the pressure loss required in the furnace due to these measures should lie in the non-critical range of less than 50 Pa. In particular for mixed gas heating, these measures are ultimately also as compatible as possible with the measures for coke oven gas heating, or at least do not have any particularly adverse effects on the operating mode of coke oven gas heating, even if coke oven gas heating is only carried out for a small part of the annual operating time. This will enable a relatively flexible operating mode, in other words a very variable furnace for a wide range of tasks.

[0049] According to the present invention, this object is achieved by a coke oven device, which is used to produce coke by coking coal or a coal mixture, wherein the coke oven device has at least mixed gas heating and optionally also intermittent coke oven gas heating, wherein the coke oven device is configured to minimize the emission of nitrogen oxides by internal thermal energy balance through measures inside the coke oven device with the help of steel plant inherent gases (especially blast furnace production) and coke oven inherent gases G1, G4, G5, and the coke oven device has a plurality of double heating flues, each heating flue having a gas combustion heating pipe and a heating pipe that guides the exhaust gas and flows downward, and these heating pipes are respectively delimited in pairs by partitions (also called bonding walls) and are separated from the corresponding furnace chamber by two mutually opposite parallel brick masonry walls, wherein the heating pipes are coupled in pairs by means of at least one upper coupling channel ducts and are also fluidly coupled to each other by means of at least one lower coupling channel for internal exhaust gas recirculation on at least one circulation flow path, respectively, wherein in the lower area on the base of the corresponding double heating flue, at least one inlet of the following groups is respectively arranged: coke oven gas inlet, combustion air inlet, mixed gas inlet; wherein, on the corresponding base, the ratio y1:y2 of the distance y1 between the facing edges of the combustion air inlet and the mixed gas inlet to the distance y2 of the inner edge (inner surface) of the partition of the corresponding heating duct is at least 10%, wherein the distance between the facing edges of the combustion air inlet and the mixed gas inlet is at least 50 mm, wherein at least one of the combustion air inlet and the mixed gas inlet is eccentrically arranged at an x ​​distance greater than 0.7 times the absolute x length of the heating duct between the opposite parallel brick masonry walls. This makes it possible to reduce NO by means of internal thermal measures x emission.

[0050] In the present invention, the distance between the combustion air inlet and the mixed gas inlet in the y direction is relatively large, wherein the relative minimum distance is defined relative to the entire y length of the corresponding heating pipe. In addition, in the present invention, an absolute minimum distance is defined (y1min=50 mm). This can advantageously influence the temperature and flow curves, respectively. The minimum distance y1 is, for example, in the range of 60 to 220 mm. The distance y2 between the opposing partitions is, for example, in the range of 250 to 400 mm.

[0051] The absolute position of the mixed gas inlet here can also be defined, for example, by a minimum distance in the y direction relative to the parallel brickwork wall and / or a minimum distance between the outer edge of the mixed gas opening and the inner edge of the partition wall (bonded wall) relative to the partition wall (for example, in particular >10 mm). The distance (relative position) between the mixed gas opening and the coke oven gas nozzle in the x direction can in particular be at least 100 mm.

[0052] In the present invention, it has been found that economically advantageous process temperatures above 1250° C. and thus high plant outputs can be ensured with good results while adhering to the above-mentioned strict limit values ​​based on geometrical measurements based on the heating duct. In this case, any increase in pressure losses can also be kept within relatively modest limits. By the relative and / or absolute positioning of the mixed gas inlet according to the invention, the desired temperature distribution can also be achieved in a particularly effective manner.

[0053] The combustion of mixed gases, which is considered less critical due to the low hydrogen fraction, has not been a major subject of developments in the reduction of nitrogen oxides in the context of the design of vertical heating ducts in combined coke ovens so far. However, the operating mode with mixed gas heating usually involves a considerable proportion of the absolute operating time of the oven. According to the invention, in particular by mixed gas heating, particularly advantageous NO reductions can be achieved. x Restore effect.

[0054] Increasing the absolute distance between the outlet positions of the "base air" and "mixed gas" combustion media, in particular in combination with the relative minimum distance relative to the entire extent of the heating duct in the y direction, makes it possible to design the furnace particularly independently of its specific volume or output range.

[0055] The different operating modes can also be described with regard to the respective functions of the individual inlets. For combined furnaces connected to a steel plant with mixed gas heating, two openings or inlets are provided in the base of the heating duct, which are an inlet for the mixed gas and an inlet for the (combustion) air. For combined furnaces subjected to coke oven gas heating, the mixed gas duct is likewise supplied with air. For furnaces specifically for coke oven gas heating (so-called rich gas furnaces), only an air inlet is required (no mixed gas inlet is required). The latter design should be understood more as a special case.

[0056] In the case of pure mixed gas heating, the arrangement of the coke oven gas inlet is relatively unimportant, so that the relative arrangement of the coke oven gas inlet can vary more or less in the longitudinal direction or in the transverse direction or in both, depending on the specific case. In this case, a reasonable compromise also depends on the expected operating time in the corresponding heating mode. According to the invention, by the absolute and relative arrangement of the inlets for combustion air and mixed gas, it is possible for different furnace designs to supply a gas with minimized NO during the majority of the absolute operating time. x An effective trade-off for emissions.

[0057] A relatively large distance between the two inlets for combustion air and mixed gas relative to the coke oven gas inlet may indeed be considered useful or even desirable; however, it has been found that the effect of the invention can even be achieved to a large extent independently of the relative arrangement of the coke oven gas inlet. In the context of the invention, this also provides further structural or process engineering variables (or degrees of freedom) for adapting the oven to a specific application.

[0058] For example, a distance y1 in the range from 100 to 300 mm is provided. For example, a ratio y1 / y2 in the range between 30% and 60% (or 0.3 and 0.6) is selected. The ratio y1 / y2 here can also be much greater, for example up to 90% (or 0.9). The ratio y1 / y2 is preferably located in a central range below 0.5. This has proven to be advantageous, in particular for the temperature distribution in the vertical direction.

[0059] It has been found that the change in distance y1 can be used as NO x In particular, for the size or range of the distance y1 according to the present invention, the effect of the NO x To date, furnace manufacturers have avoided changing the distance y1. In particular, this distance is not marked as NO x This purposeful change of the distance y1 is therefore also unjustifiable, especially since at first glance the change of the distance does not allow any consideration of NO x Any systematic conclusions of emissions.

[0060] The x-position of the combustion air inlet and the mixed gas inlet can be defined in particular relative to their center points. In particular, at least one of the combustion air inlet and the mixed gas inlet, more particularly the center point thereof, can be arranged eccentrically between opposite parallel brickwork walls at an x-distance greater than 0.8 times the absolute x-length of the heating duct. Such an eccentricity in the x-direction can also ensure an advantageous primary mixing of the gases before combustion.

[0061] Steelworks-specific gases are to be understood here as gases which are associated with steel production in a broad sense, including in particular so-called converter gases. Strictly speaking, converter gases are not related to the production of crude iron in the blast furnace, but are to be considered as belonging to the downstream process chain of the actual steel production in the steelworks. The term "steelworks-specific gases" may also be understood to include in particular hydrocarbon fractions or natural gas, in particular as a mixture component.

[0062] A relatively small ratio y1 : y2 , more particularly below 15%, may be advantageous in particular in relatively large devices.

[0063] The arrangement according to the invention also enables relatively moderate flame temperatures to be achieved, for example for relatively high nozzle brick temperatures, more particularly a flame temperature of no more than about 1600°C when the mixed gas is heated at a nozzle brick temperature of at least 1300°C or 1320°C.

[0064] It has been found that the arrangement according to the invention can be achieved both for a structural design of double heating ducts in a "back-to-back" heating mode (the flow directions in adjacent double heating ducts are respectively vertically oriented in the same manner) and for a structural design of double heating ducts in a forward flow traverse mode (vertically opposite flow directions in adjacent heating ducts). In the case of "back-to-back" heating, a single lower recirculation channel or a plurality of recirculation channels, in particular pairs of recirculation channels, can be selectively provided. In the case of a forward flow traverse, pairs of lower recirculation channels are preferably provided.

[0065] In the case of the "forward combustion" operating mode, for example, the odd-numbered #1, #3, #5, #7, #9, .. (n+2) heating flues are burned, or after the heating conversion, the even-numbered #2, #4, #6, #8, .. (n+2) heating flues are burned. In particular, at least one recirculation opening is present in each bonding wall. For a furnace of this type, preferably, there are at least two lower recirculation openings, which surround or delimit or enclose the stepped air ducts in the bonding wall. It has been found that by means of the flue gases flowing through the recirculation openings, a combustion inert sandwich can be formed at least partially in the horizontal direction relative to at least one medium (gas and / or air) received. It has been found that in this way, the combustion can be delayed in the vertical direction, which is beneficial for the temperature distribution. For example, in each bonding wall, each layer has at least two recirculation openings. In one of the five lowest bonding wall layers, the first pair of recirculation openings is preferably present. More particularly, for reasons of stability, further openings are provided only in the next layer located above it (eg vertical layer number 3 ), and these openings may in particular be arranged parallel to layer number 1 (symmetrically).

[0066] In the case of the "back-to-back" operating mode, in particular, the heating flue numbers #1, #4, #5, #8, #9, .. (starting with 1, n+3 / n+1) are burned, or after the heating conversion, the heating flue numbers #2, #3, #6, #7, #10, #11, .. (starting with 2, n+1 / n+3) are burned. It has been found that with the help of the flue gases flowing back through the recirculation openings, a combustion inert interlayer can be formed relative to at least one of the received media (gas and / or air). In particular, at least one recirculation opening is provided in each second bonding wall. For example, a separate recirculation opening (more particularly, a relatively large opening) is provided in the center of the bonding wall. For example, the stepped air duct and the recirculation opening are each located only jointly on the corresponding bonding wall. Preferably, at least one additional recirculation opening is provided in at least one wall layer located above it.

[0067] The respective arrangement of the at least one recirculation channel can be selected freely to a large extent. Optionally, its arrangement can be defined relative to the arrangement of the other inlets. Optionally, an x-coordinate and / or a z-coordinate can be specified for the arrangement of the center point of the recirculation channel. For example, the (lowest) one or more recirculation channels are arranged at a vertical position less than 2 m above the base. In a variant, the recirculation channels are arranged in pairs at each vertical position, more specifically, in an arrangement symmetrical with respect to the x-length of the heating flue. For example, one or two pairs of recirculation channels are arranged at the same vertical position of the x-coordinate as at least one of the air inlet and the mixed gas inlet.

[0068] It has been found to be advantageous to arrange at least one of the air inlet and the mixed gas inlet relatively close to the brickwork wall at a relatively small x distance, more particularly not more than 50 mm or even only not more than 20 mm or 10 mm.

[0069] Furthermore, it has been found that the air inlet and the mixed gas inlet can optionally be arranged so as to completely overlap in the x-direction, in other words without any offset or without the geometrically smaller inlet protruding beyond the geometrically larger inlet in the x-direction. Furthermore, it has been found that the air inlet and the mixed gas inlet can also optionally be arranged so as not to overlap at all in the x-direction, in other words with such a large offset that it is not possible to determine an overlap in the x-direction.

[0070] In particular, each heating duct provides only one type of inlet described here, ie only one combustion air inlet and only one mixed gas inlet are provided.

[0071] Furthermore, it has been found that the combustion air can preferably be supplied in a stepped manner, more specifically by two-stage combustion over the entire height of the respective heating chimney. The corresponding protrusions or inlets for the stepped air can be arranged in a manner best adapted to the specific application.

[0072] In an exemplary embodiment, the ratio y1:y2 is at least 25%. This also enables efficient distribution / mixing of the gas throughout the heating conduit.

[0073] In an exemplary embodiment, the distance y1 is at least 100 mm, such as at least 150 mm, such as 200 to 250 mm. This allows the gas flow paths to be set and controlled more individually.

[0074] In an exemplary embodiment, the ratio y1:y2 is at least 35%, more particularly not more than 50% or not more than 60% or not more than 70%. It has been found that starting from 10% or 15%, the distance y1 can be further increased or even maximized, while in NO x There are no attendant perceptible disadvantages in terms of emissions or in terms of other furnace operating parameters. This opens up further design freedom.

[0075] In an exemplary embodiment, the distance y1 is at least 150 mm or at least 200 mm. This allows ensuring an advantageous relative arrangement even when using furnaces of relatively high volume.

[0076] In an exemplary embodiment, the distance y1 is not greater than 350 mm or not greater than 375 mm. It has been found that a distance y1 greater than 400 mm may be associated with disadvantages in other furnace process parameters. The suggestion in the present invention is to limit the distance to below an upper limit of 400 mm.

[0077] In an exemplary embodiment, the distance y1 ranges from 200 mm to 300 mm or from 150 mm to 250 mm. These ranges or this spectrum of distances have been or have proven to be particularly advantageous in many experiments. More precise specifications of the distances can be defined according to the total length of the furnace and / or the heating duct, respectively.

[0078] This distance is preferably the same in each heating duct of the coke oven plant.A similar construction or a symmetrical design for all heating ducts also has thermal and structural advantages.

[0079] A relatively large ratio y1 : y2 , more particularly higher than 25% or even higher than 35% or 40%, may be advantageous in particular in the case of relatively small devices.

[0080] In an exemplary embodiment, the geometric center points of the inlet of the respective heating flue and the inlet of at least one lower coupling channel, more particularly the geometric center point of one of the plurality of lower coupling channels further removed relative to the combustion air inlet and the mixed gas inlet, define a triangular or quadrilateral arrangement (polygonal arrangement), the surface area (A) of which in plan view is at least 50 cm², more particularly at least 200 cm² or at least 300 cm² or at least 500 cm² or at least 700 cm² or at least 900 cm², more particularly between 1000 cm² and 1350 cm². This enables an efficient distribution of mass flows and energy flows to a large extent independently of the individual structural characteristics of the respective furnace. It has been found that a particularly strong effect can be achieved with a surface area exceeding only 200 cm². In particular, the effect can be further enhanced with a surface area exceeding 300 cm² or 500 cm².

[0081] In an exemplary embodiment, the triangular or quadrilateral arrangement has a surface area (A) in plan view of not more than 2000 cm², more particularly not more than 1800 cm² or not more than 1500 cm², or not more than 1300 cm² or not more than 700 cm², more particularly between 1000 cm² and 1300 cm². These upper limits may also mark advantageous ranges that are still acceptably achievable from a construction point of view. It has been found that the selected surface area must not be too large, in order in particular to be able to avoid possible adverse side effects depending on the furnace construction. A surface area of ​​less than 1500 cm² may already be advantageous for particularly large furnace constructions, although, in particular in the case of very large or very high furnace cavities, the upper limit may also be greater than 1500 cm².

[0082] The lower / upper limits which are particularly preferred here may also depend, for example, on the furnace chamber height, for example, as explained in more detail in conjunction with the description of the figures. More specifically, for furnace chambers with a height of more than seven (7) meters, the lower limit may be increased by 100 or 200 cm. 2.

[0083] A relatively triangular or quadrilateral arrangement with vertices (layer geometry relative to each other) defined by the geometric center points of the mixed gas inlet and the combustion air inlet and the (further removed) lower recirculation channel also offers the advantage of very efficient utilization of the available (combustion) space, more particularly making it possible to advantageously adjust the mixing ratio of the gases. In particular, in the case of relatively large surface areas, an advantageous distribution of mass and energy flows can be ensured. In particular, by means of an inlet arrangement widely distributed over the available base area, a particularly advantageous combustion in the vertical direction (in particular, a greatly delayed combustion) can be ensured for typical heating modes (mixed gas heating and coke oven gas heating, respectively).

[0084] In particular, the vertices of the triangular arrangement are defined by the geometrical centre points of the mixed gas inlet and the combustion air inlet and the centre point of the (further removed) lower recirculation channel and are therefore offset inwardly from the respective partition with respect to the discharge plane.

[0085] In an exemplary embodiment, on the corresponding base, the edges of the combustion air inlet and the mixed gas inlet facing the parallel brickwork wall are arranged at different distances x1, x2 relative to at least one of the two opposite parallel brickwork walls of the corresponding double heating flue, more specifically, with a distance difference of at least 10 mm or at least 50 mm. Such an offset in the x direction can also achieve additional differentiation in temperature distribution and flow distribution.

[0086] It has been found that the distances x1, x2 relative to the two parallel brickwork walls can be set relatively freely. The corresponding openings / inlets can also have different dimensions in the x-direction and the y-direction and can have different geometries. At the same time, the inlets can also be offset in the x-direction, with the cross section remaining constant.

[0087] In an exemplary embodiment, the cross-sectional surface area of ​​the combustion air inlet and / or the mixed gas inlet on the respective base is at least 30 cm² or at least 50 cm². This also makes it possible to further promote the flattening of temperature peaks.

[0088] In an exemplary embodiment, the cross-sectional surface area of ​​the combustion air inlet and / or the mixed gas inlet is no greater than 500 cm 2 or not more than 400cm 2 These relatively high surface areas also facilitate widespread introduction of heat.

[0089] In an exemplary embodiment, the corresponding inlet cross-sectional area is relatively large, more particularly 2 to 3 times larger than the cross-sectional surface areas customary to date. In the prior art, only significantly smaller cross-sectional surface areas are described, for example in the range of about 50 to 100 cm². For example, the above-mentioned publication by K. WESSIEPE describes dimensions of 51 mm×144 mm, in other words only about 75 cm².

[0090] In particular, in this case, it is also possible to design a connection opening for the inversion of the exhaust gas flow or flue gas flow (channel) with a channel surface area of ​​at least 500 cm². This makes it possible not only to keep the undesirable increase in the pressure loss in the heating duct within an acceptable range, which is also advantageous from an economic point of view, more particularly at less than 50 Pa. This not only has the effect of eliminating a reinforced or additional negative pressure source. In other words, no exhaust gas stack needs to be raised and / or no additional blower is required.

[0091] In an exemplary embodiment, the cross-sectional geometry of the combustion air inlet and / or the mixed gas inlet is rectangular or oval or circular. This geometry can also be optimized with respect to structural indications or stability aspects, for example. More particularly, the gases can also be further optimized by adjustable discharge openings (inlets), more particularly by sliding bricks.

[0092] Further measures may have further advantageous effects. In particular, based on the change of the position of the inlet relative to an asymmetric arrangement (at least for the base air and mixed gas), further optimization may be performed by, for example, a non-parallel arrangement on the foundation relative to the parallel brickwork wall.

[0093] It has been found that by means of the measures according to the invention, in particular in the case of mixed gas heating, it is possible to achieve NO x The formation of NO x At first glance, this percentage does not seem revolutionary, but it may confirm economic operation, especially in cases where economic operation has not been possible so far due to emission regulations and restrictions to specified maximum temperatures.

[0094] In an exemplary embodiment, the cross-sectional area of ​​the combustion air inlet and / or the mixed gas inlet is adjustable in geometry and / or size on the respective base, more particularly, is adjustably configured by means of at least one movable sliding brick and / or by means of at least one interchangeable / removable nozzle. By these means, further optimizations can be achieved, in particular also during operation (fine tuning).

[0095] In an exemplary embodiment, at least one upper recirculation channel coupling two respective heating ducts of a respective double heating chimney is provided in the upper region for reciprocating gas transport, wherein the recirculation channel has a cross-sectional surface area of ​​at least 250 cm², more particularly not more than 1200 cm². 2 Or not more than 1000cm 2 In this way, among other factors, optimization can be carried out in a relatively flexible manner through relatively large channel openings.

[0096] In an exemplary embodiment, the paired heating ducts are fluidically coupled to one another by means of at least two lower coupling channels, wherein the combustion air inlet is arranged at least approximately at the same x position as the corresponding lower coupling channel, more specifically, the combustion air inlet and the respective center point of the corresponding channel are arranged at the same x coordinate. This promotes mixing of recirculation gas and combustion air in a particularly advantageous manner, in particular before combustion.

[0097] In an exemplary embodiment, the combustion air inlet and the mixed gas inlet are offset in the x-direction relative to the opposite parallel brickwork wall. This variation can promote effective mixing. Different geometries and / or cross-sectional areas can also be provided in this case.

[0098] In an exemplary embodiment, the ratio x1:y1 or x2:y1 of the combustion air inlet and / or the mixed gas inlet relative to the distance x1, x2 of the opposite parallel brickwork wall is at least 90% and / or not more than 290%, more particularly between 200% and 250% relative to the distance y1. In other words, the inlet is kept relatively far from the center in the x-direction, i.e. at least one of the inlets. This allows further differentiation of the gas distribution.

[0099] In an exemplary embodiment, the combustion air inlet is arranged closer to the opposite parallel brickwork wall than the mixed gas inlet (or vice versa), more particularly, more particularly with a distance difference of at least 10 mm or at least 50 mm in at least an approximately central region between the opposite parallel brickwork walls. Such an offset in the y direction allows the flow path to fan out further.

[0100] In an exemplary embodiment, the combustion air inlet and the mixed gas inlet of the double heating duct are arranged relative to each other so that the line connecting the inlets is diagonal or at least extends approximately diagonally through the respective heating duct, more specifically a straight diagonal through the center point of the inlet, more specifically a diagonal at an angle in the range of 40° to 50° relative to the horizontal x-direction, more specifically a diagonal through the vertex between the parallel brickwork wall and the bonded wall. In this way, an advantageous local diversification of the temperature transfer and mass transfer can be provided in the respective heating duct. The diagonal design can also be characterized by an at least approximately flush arrangement on the line between the diagonally opposite corners.

[0101] According to the present invention, the above-mentioned purpose is also achieved by means of a coke oven device, which is used to produce coke by coking coal, wherein the coke oven device has at least mixed gas heating, and the emission of nitrogen oxides of the coke oven device is minimized by internal thermal energy compensation. The coke oven device includes a plurality of double-heating flues with paired heating pipes, which are respectively defined by partitions in pairs and separated by two mutually opposite parallel brick masonry walls, wherein at least one inlet of the following groups is arranged on the base of the corresponding heating pipe: a coke oven gas inlet, a combustion air inlet, and a mixed gas inlet; wherein the heating pipes are fluidly coupled to each other in pairs by means of at least one upper coupling channel and also by means of at least two lower coupling channels, so as to be used for internal exhaust gas recycling on at least one circulation flow path, respectively. Ring, wherein on the respective base, the ratio of the distance between the facing edges of the combustion air inlet and the mixed gas inlet to the distance to the inner edge of the partition is at least 10%, wherein the distance between the facing edges of the combustion air inlet and the mixed gas inlet is at least 50 mm, wherein at least one of the combustion air inlet and the mixed gas inlet is eccentrically arranged at an x ​​distance greater than 0.7 times the absolute x length of the heating duct between the opposite parallel brickwork walls, and wherein the heating ducts are fluidically coupled to each other in pairs by means of at least two lower coupling channels, wherein the combustion air inlet is arranged at least approximately the same x position as the corresponding lower coupling channel, more particularly the respective center points of the combustion air inlet and the corresponding channel are arranged at the same x coordinate, more particularly in combination with the above-mentioned features of the coke oven device. This provides the above-mentioned advantages, in particular with regard to the primary mixing of the recirculated gas and the combustion air before combustion.

[0102] According to the invention, the above-mentioned object is also achieved by means of a coke oven device for producing coke by coking coal, wherein the coke oven device has at least mixed gas heating and the emission of nitrogen oxides is minimized by internal thermal energy compensation, the coke oven device comprises a plurality of double heating flues with heating pipes, the heating pipes are respectively bounded from each other in pairs by partitions and separated by two mutually opposite parallel brickwork walls, wherein the heating pipes are fluidically coupled to each other in pairs by means of at least one upper coupling channel and also by means of at least one lower coupling channel for internal exhaust gas recirculation on at least one circulation flow path, wherein at least one inlet of the following group is arranged in the lower region on the base of the corresponding heating pipe: coke oven gas Inlet, combustion air inlet, mixed gas inlet; wherein, on the corresponding base, the ratio y1:y2 of the distance y1 between the facing edges of the combustion air inlet and the mixed gas inlet to the distance y2 of the inner edge of the partition is at least 10%, wherein the distance between the facing edges of the combustion air inlet and the mixed gas inlet is at least 50 mm, wherein at least one of the combustion air inlet and the mixed gas inlet is eccentrically arranged at an x ​​distance greater than 0.7 times the absolute x length of the heating pipe between the opposite parallel brick masonry walls; more particularly the above-mentioned coke oven device; wherein the distance is further at least 100 mm, more particularly at least 150 mm, wherein the combustion air inlet and the mixed gas inlet are offset in the x direction relative to the opposite parallel brick masonry walls. This produces many of the above-mentioned advantages.

[0103] According to the present invention, the above-mentioned object is also achieved by means of a coke oven device, which is used to produce coke by coking coal or a coal mixture, wherein the coke oven device has at least mixed gas heating and optionally also intermittent coke oven gas heating, wherein the coke oven device is configured to minimize the emission of nitrogen oxides by means of an internal thermal energy balance of the inherent gas of the steel plant and the inherent gas of the coke oven, and the coke oven device has a plurality of double heating flues, each heating flue having a gas combustion heating pipe and a heating pipe for guiding the exhaust gas and flowing downward, wherein the heating pipes are respectively defined in pairs by partitions and are separated from the corresponding furnace chamber by two mutually opposite parallel brick masonry walls. Separated, wherein the heating ducts are fluidically coupled to each other in pairs by means of at least one upper coupling channel and also by means of at least one lower coupling channel for internal exhaust gas recirculation on at least one circulation flow path, respectively, wherein in the lower region on the base of the respective double heating flue, at least one inlet from the following groups is respectively provided: coke oven gas inlet, combustion air inlet, mixed gas inlet, wherein the lower coupling channel for internal exhaust gas recirculation is a coupling duct, which extends at least in sections through a central section region located in pairs below the heating ducts and connects the gas combustion heating ducts to the exhaust gas-conducting, downwardly flowing heating ducts. Advantageously, the recirculating gas is introduced into the gas combustion heating duct essentially in a vertical direction via the coupling duct. Alternatively, it is known from the general prior art that the recirculating gas flows inwardly into the gas combustion heating duct in an essentially horizontal direction.

[0104] Here, the coupling duct can extend below the double heating flue in such a way that the inlet opening of the coupling duct is designed to receive or accommodate the recirculated exhaust gas in the base area of ​​the heating duct that guides the exhaust gas and flows downward, and the outlet opening of the coupling duct is designed to discharge the recirculated exhaust gas in the base area of ​​the gas combustion heating duct. In addition, it is conceivable that at least the inlet opening is centrally constructed between the center / coupling partition and the outer / separating partition opposite to the center / coupling partition. Another possibility is that the outlet opening is centrally constructed between the center / coupling partition and the outer / separating partition opposite to the center / coupling partition. In this case, the center / coupling partition has at least a channel opening or a coupling channel, more specifically, an upper coupling channel for the recirculation of the recirculated gas, and is arranged between the two heating ducts of the double heating flue. However, it is also possible that at least the outlet opening and / or the inlet opening are constructed in a dispersed manner between the center / coupling partition and the outer / separating partition opposite to the center / coupling partition, more specifically closer to the center / coupling partition when viewed in the y direction. In the x-direction, the inlet opening and / or the outlet opening can be constructed in the center between the corresponding parallel brick masonry walls. A decentralized construction is also conceivable. In addition, it is conceivable that the coupling duct has an inlet opening and / or an outlet opening, the size of which, more particularly the cross-sectional size, covers a quarter, more particularly a third, of the base area of ​​the heating duct and / or the gas combustion heating duct that guides the exhaust gas and flows downward. The coupling duct can be designed to have a circular, elliptical, angled, more particularly rectangular or multi-angle cross section.

[0105] The central section area represents refractory bricks, which connect a single combustion well or a dual heating flue to the regenerator (air preheating) by means of ducts. Extending through this central section area, for example, is a gas duct in which fuel gas and air from the regenerator are reciprocatingly passed upward into the dual heating flue, more specifically into the gas combustion heating duct for combustion, and exhaust gases are passed from the dual heating flue downward into the regenerator, more specifically from the heating duct that conducts the exhaust gases and flows downward into the regenerator for evacuation.

[0106] According to the invention, the above-mentioned object is also achieved by means of a method for operating a coke oven plant, more particularly for operating the above-mentioned coke oven plant, which is used to produce coke by coking coal or a coal mixture, wherein the coke oven plant is optimized to minimize nitrogen oxide emissions by internal thermal energy compensation with the help of steel plant native gases (gases from blast furnaces) and coke oven native gases through measures within the coke oven plant, the coke oven plant having at least mixed gas heating and optionally also intermittent coke oven gas heating, wherein, in a corresponding double-heated flue of the coke oven plant, an internal exhaust gas recirculation is established on at least one circulation flow path around the partition by means of at least one coupling channel through the partition, the double-heated flue having a combustion heating A heat pipe and a heating pipe for guiding exhaust gases, wherein at least two gases from the following group are received in the lower region on the base of the corresponding double heating flue: coke oven gas, combustion air, mixed gas, wherein the received gas group includes at least two gases combustion air and mixed gas; wherein at the corresponding base, the combustion air and the mixed gas are received on the flow path at a distance y1 relative to each other in a ratio y1:y2 of at least 10% of the distance y2 from the inner edge (inner side surface) of the partition of the corresponding heating pipe, wherein the distance y1 of the two received flow paths is at least 50 mm, wherein the combustion air and / or the mixed gas are received eccentrically at an x ​​distance greater than 0.7 times the absolute x length of the heating pipe between the opposite parallel brickwork walls. This provides the above-mentioned advantages.

[0107] In one embodiment, on the respective base, the cross-sectional area of ​​the combustion air inlet and / or the mixed gas inlet is adjusted in terms of geometry and / or size, more specifically by means of at least one sliding brick. This allows further optimization.

[0108] In one embodiment, in the case of mixed gas heating, the flame temperature does not exceed 1700°C or does not exceed 1600°C or does not exceed 1500°C, more particularly, at a nozzle brick temperature of at least 1300°C or at least 1320°C, which also allows a favorable framework in terms of operating parameters and output. In particular, the device can be selectively operated to maximize output (without strict NO x limit) or operate selectively to minimize NO x Compared with existing installations, for comparable NO x emission levels, higher outputs can be achieved.

[0109] In one embodiment, the gas flow in the respective heating duct is set so that the ratio of the flame temperature to the nozzle brick temperature is minimized, more specifically at a nozzle brick temperature of at least 1300° C. or 1320° C. A ratio minimized in this way can mark a relatively uniform temperature distribution, with very few or extremely small areas with temperature peaks, respectively. This also results in process optimization related to yield and economy.

[0110] In the present invention, the bumps in the temperature profile can be evened out in height. Previously, in many configurations, there were usually two-step temperature profiles in height, each with a relatively strong and obvious "bump" or a relatively significant uneven distribution. The arrangement in the present invention allows the temperature profile to be flattened, especially in large vertical sections of the entire heating flue.

[0111] In one embodiment, at the respective base, through the respective inlet, the mixed gas and / or the combustion air is admitted at least approximately in the vertical direction. Alternatively, at the respective base, through the respective inlet, the mixed gas and / or the combustion air can be admitted in a direction inclined relative to the vertical direction. At the respective base, selectively admitting the mixed gas and / or the combustion air in a vortex or vortex pulse is allowed on at least one spiral flow path. This also enables fine-tuning of the flow paths, respectively.

[0112] In one embodiment, the gases admitted (more specifically, combustion air, mixed gas) and / or the circulating gases are directed or guided in the horizontal direction, more specifically, on a plurality of vertical levels, more specifically, through baffle inner parts or baffles or bricks or shields, more specifically made of refractory material, respectively. This enables further optimization measures to be implemented with regard to the internal energy mixing and the flattening of the temperature curve, especially at the height of the heating chimney.

[0113] In one embodiment, the gas (combustion air and / or mixed gas) is admitted through inlets at different vertical levels, more specifically the mixed gas inlet is at a vertical level above the combustion air inlet, more specifically through the mixed gas inlet in an arrangement on the base above the base. This also allows further influencing of the temperature distribution.

[0114] According to the invention, the above-mentioned object is also achieved by means of a method for operating a coke oven plant, more particularly for operating a method according to the above-mentioned coke oven plant, which is used to produce coke by coking coal or a coal mixture, wherein the coke oven plant is optimized to minimize nitrogen oxide emissions by internal heat energy compensation by means of steel plant natural gases and coke oven natural gases through measures within the coke oven plant, wherein the coke oven plant has at least mixed gas heating and optionally also intermittent coke oven gas heating, wherein in a corresponding double heating flue of the coke oven plant, an internal exhaust gas recirculation is established on at least one circulation flow path around the partition by means of at least one coupling channel through the partition, the double heating flue having a heating duct for combustion and a heating duct for guiding the exhaust gas, wherein at least two gases from the following group are received in the lower area on the base (5.4) of the corresponding double heating flue: coke oven gas (G1a), combustion air (G1), mixed gas (G1b), wherein the gas group received includes at least two gases combustion air (G1) and mixed gas. Here, the recirculated exhaust gas of the exhaust gas recirculation flows through a coupling conduit, which extends at least in sections in the region of a central section located in pairs below the heating conduit and connects the gas combustion heating conduit to the heating conduit that guides the exhaust gas and flows downward, and the flow causes the recirculated gas to be introduced into the gas combustion heating conduit essentially in a vertical direction. Here, "essentially" means that the recirculated gas flows or is received into the heating conduit at least almost / approximately / roughly in a vertical direction (z direction).

[0115] According to the invention, the above-mentioned object is also achieved by means of the use of combustion air inlets and mixed gas inlets in a coke oven installation, more particularly in the above-mentioned coke oven installation, which comprises a plurality of dual heating ducts each with two heating pipes, the coke oven installation being used to produce coke by coking coal or a coal mixture, wherein the coke oven installation has at least mixed gas heating and optionally also intermittent coke oven gas heating, wherein in the respective dual heating duct, an internal exhaust gas recirculation is established on at least one circulation flow path by means of at least one coupling channel, wherein, in order to minimize nitrogen oxide emissions by internal thermal energy compensation, the inlets are arranged with a ratio y1:y2 of at least 10% of the distance y1 between the facing edges of the combustion air inlet and the mixed gas inlet and the distance to the inner edge of the partition of the respective heating pipe, wherein the distance y1 between the facing edges of the combustion air inlet and the mixed gas inlet is at least 50 mm here. This leads to the above-mentioned advantages.

[0116] According to the invention, the above-mentioned object is also achieved by the use in heating ducts of a plurality of double-heating chimneys of a coke oven installation, more particularly in the above-mentioned coke oven installation, for minimizing the emission of nitrogen oxides by internal heat energy compensation, wherein in the respective double-heating chimney, an internal exhaust gas recirculation is established on at least one circulation flow path by means of at least one coupling channel, wherein the combustion air and the mixed gas are admitted at a distance ratio y1:y2 of at least 10% and at a distance of 50 m relative to each other, more particularly at a flame temperature heated with mixed gas of not more than 1700° C. or not more than 1600° C. or not more than 1500° C., more particularly at a nozzle brick temperature of at least 1300° C. or at least 1320° C. This leads to the above-mentioned advantages, in particular in the case of an (optional) increase in the nozzle brick temperature by at least 20 Kelvin relative to the existing operating mode, for the same or lower NO x emission.

[0117] With the method described, all the advantages which have been described for the coke oven plant according to the first aspect of the invention are achieved.

[0118] It will be understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination specified but also in other combinations or alone, without departing from the scope of the present invention.

[0119] Other features and advantages of the present invention will be apparent from the following description of at least one exemplary embodiment with reference to the accompanying drawings, and from the drawings themselves. BRIEF DESCRIPTION OF THE DRAWINGS

[0120] Figure 1A , Figure 1B , Figure 1C , Figure 1D , Figure 1E , Figure 1F , Figure 1G , Figure 1H A schematic diagram showing a double-heated flue or coke oven according to the prior art, in cross-sectional side view and plan view respectively;

[0121] Figure 2A , Figure 2B , Figure 2C , Figure 2D , Figure 2E Schematic illustrations of a dual heating chimney or coke oven arrangement according to an exemplary embodiment are shown in cross-sectional side view and plan view, respectively;

[0122] Figure 3 , Figure 4 , Figure 5 , Figure 6, Figure 7 The relative arrangement of the inlets according to an exemplary embodiment is respectively shown in the form of a plan view;

[0123] Figure 8 The relative arrangement of the inlets according to the prior art is shown in a schematic plan view;

[0124] Fig. 9 The configuration variables in the double-heating flue are shown in a plan view;

[0125] Fig. 10A , Fig. 10B , Fig. 10C respectively show in the form of a schematic plan view the relative arrangement of the inlet with respect to the further removed lower recirculation channel according to an exemplary embodiment;

[0126] Fig.11 shows in a schematic plan view the relative arrangement of the inlet with respect to the individual lower recirculation channels according to an exemplary embodiment;

[0127] Fig.11a shows in a schematic plan view the relative arrangement of the inlet with respect to the individual lower recirculation channels according to an exemplary embodiment;

[0128] Fig.12 A diagrammatic plan view of a commutation section is shown with a relative arrangement of inlets according to the prior art;

[0129] Fig.13A , Fig. 13B A diagram of a flow conversion section is shown in each case in the form of a schematic plan view with a relative arrangement of the inlets according to one of the exemplary embodiments;

[0130] Fig.14 , Fig.15 , Fig.16 , Fig.17 , Fig.18 , Fig.19 A dual heating chimney according to an exemplary embodiment is schematically shown in a cross-sectional side view, respectively.

[0131] In the case where reference symbols are not explicitly described with respect to an individual figure, reference is made to the other figures. In the figures describing the prior art, the position and angular alignment of individual inlets and channels or flow paths are shown only by way of example (in particular only in individual heating ducts) and are not complete or may be arranged angularly inaccurately.

[0132] In the drawings describing the invention, the positions and angular alignments of the individual inlets and channels or flow paths (in particular only in the individual heating ducts) are schematically shown, and the values ​​of the individual distances are defined in more detail in the description. It should be noted that, for the drawings relating to the prior art, different reference numerals have been used for the same features compared to the drawings showing exemplary embodiments of the invention. However, this has no influence on the possibility of combining the individual features with one another. DETAILED DESCRIPTION

[0133] Figure 1A , Figure 1B , Figure 1C , Figure 1D , Figure 1E , Figure 1F , Figure 1G , Figure 1H The coke oven 1 is shown in the form of a horizontal chamber furnace, which has a plurality of furnace chambers 2, each of which accommodates a coal charge. The furnace chambers 2 have a height of, for example, 6 to 8 m. The furnace chambers 2 are separated by parallel brick masonry walls 3, each extending in the yz plane. Between the two parallel brick masonry walls 3, pairs of heating pipes 5.1, 5.2 form a double heating flue 5, respectively, the inner wall 5.3 of the heating flue 5 defines a heating chamber, which is passed through by the air flow (without coal) from the corresponding furnace chamber. The heating pipes 5.1, 5.2 are operated alternately as heating pipes for combustion or for guiding exhaust gases, which need to be switched in the flow direction and are performed, for example, within a cycle of 20 minutes.

[0134] The paired heating pipes are each separated from each other by a coupling partition (bonded wall) 4, in which coupling channels 4.4 are arranged at the top and bottom, through which the circulating flow 9 of the recirculated exhaust gas can be realized. Adjacent double heating flues are completely separated from each other by a dividing partition 4a without any channel.

[0135] In the partitions 4, 4a, respectively, a stepped air duct 4.1 is arranged, which is coupled to the heating channel via at least one combustion stage 4.2 or a corresponding inlet or outlet. The corresponding combustion stage 4.2 can be arranged at a characteristic vertical position. For example, two or three vertical positions are defined, at which the stepped air is received.

[0136] The individual walls / partitions consist in particular of bricks, which each define a wall layer according to their dimensions.

[0137] The x-direction characterizes the width of the furnace 1 , the y-direction the depth (or the horizontal injection direction in the case of a horizontal chamber furnace) and the z-direction the vertical (vertical axis). The central longitudinal axis M of the respective heating duct passes through the center of the respective heating duct, said center being arranged centrally in the x-direction and in the y-direction relative to the inner surface / wall (this is not explicitly marked; for example, said center is located in the center of the respective partition having a circulating flow around it, more particularly in the center of a stepped air duct arranged in the center). Here, the term "centered" or "center" relates to the midpoint in the xy plane and also to the vertical direction (z).

[0138] In the so-called burner plane 5.4 or at the base of the corresponding heating duct, a plurality of inlets are provided, in particular a (first) combustion air inlet 6 for coke oven gas heating and more particularly a further combustion air inlet 7 for mixed gas heating, as well as a coke oven gas inlet 8. The gas introduced through these inlets flows upwards over the wall surface 4.3 of the partition and also over the inner wall of the parallel brickwork wall.

[0139] The following can be stated as the temperatures of the coke oven 1 which are characteristic of the oven builder / operator: nozzle brick temperature T1, (gas) temperature T2 in the individual heating ducts, temperature T3 in the oven chamber. The invention relates in particular to a very uniform profile (in particular also in the vertical direction) with respect to the temperature T2.

[0140] Refer to the following Figure 1F to Figure 2E The individual gas streams are described. The gas stream G1 identifies the newly admitted or supplied heating gas or combustion air, respectively. The gas stream G1 can comprise the gas stream G1a (coke oven gas) and / or the gas stream G1b (mixed gas). The gas stream G4 identifies the recirculated exhaust gas, which is returned or guided in a cyclic manner. The gas stream G5 identifies the gas or air from the corresponding combustion stage 4.2, 14.11, and the gas stream G6 identifies the exhaust gas discharged from the corresponding heating duct or heating flue.

[0141] Figure 1D The recirculation arrows shown in are only schematically shown and do not exactly reflect the direction of the corresponding air flow.

[0142] Figure 1G A heat exchanger 5.6 with a single opening 5.61 is schematically shown, through which the gas can be diverted in the head region of the heating duct. The heat exchanger 5.6 is separated from the corresponding double heating flue by a (middle) top plate 5.7. The heat exchanger 5.6 is independent of the circulating flow 9. The distance E between the heat exchanger 5.6 and the channel 4.4 can have a structural design that is individual for each furnace. The reference symbol E can also characterize the cross-sectional surface area. The cross-sectional surface area E is preferably at least 300 cm² or at least 340 cm².

[0143] For the sake of greater clarity, the central part of the furnace arranged below the burner plane 5.4 is deliberately not shown. The inward passage of the gas and the regulation of the volume flow can be carried out in the central part.

[0144] Figure 2A , Figure 2B , Figure 2C , Figure 2D , Figure 2E A coke oven device 10 according to an exemplary embodiment is shown, which includes: a furnace chamber 10.2, a combustion heating duct 11, an inner wall 11.1, an exhaust gas guiding heating duct 12, a double heating flue 13, a partition 14 with an inner surface 14.3, a dividing partition 14a without a channel, a stepped air duct 14.1 with a combustion step 14.11, a coupling channel 14.2, a protrusion 14.4, a straight brick masonry wall 15 with an inner surface 15.1, a combustion air inlet 16, a mixed gas inlet 17, a coke oven gas inlet 18, and a sliding brick 19.

[0145] Reference Figure 2A , Figure 2B , Figure 2C , Figure 2D , Figure 2E , the distances and relative positions of various inlets and channels according to the present invention are described below with respect to other exemplary embodiments.

[0146] exist Figure 2A The arrangement of pairs of inlets 16 , 17 opposite inlet 18 is schematically shown in FIG. 1 (in a plurality of heating ducts).

[0147] Figure 2B The inlets 16 , 17 are shown to have a relatively significant outward offset (eccentrically) in the x direction and to be relatively far apart from one another in the y direction. The arrangement of the optional coke oven gas inlet 18 is independent of this and can be selected freely to a large extent.

[0148] Figure 2C It is shown that, as a result of the offset in the x-direction and the y-direction, an advantageous relative arrangement with respect to the stepped air G4 can also be achieved. Figure 2C The angles indicated in for the angular orientation of the inlets can be varied for each inlet individually. Depending on the design of the central section, for example, an angle in the range of 5° to 10° may be a reasonable compromise between additional structural cost and device complexity and achievable thermal and / or fluid effects.

[0149] Figure 2C The channels 14.2 and the stepped gas inlets 14.11 shown in FIG. 1 may also vary in arrangement, number and geometry according to the variants shown or discussed in the other figures.

[0150] Refer to the following FIG. 2B to FIG. 2E The individual gas flows are described. According to the invention, a respective gas flow path GP1 identifies a flow path or inflow path for at least one gas G1 introduced via an inlet. A respective gas flow path GP4 identifies a flow path for the recirculated exhaust gas / flue gas G4, and a respective gas flow path GP5 identifies a flow path for the gas G5 introduced in stages.

[0151] Figure 2D In particular, a relatively high distance y1 is shown.

[0152] Figure 2E Shown with Figure 2C A view similar to the view of . Figure 2C and Figure 2E The inflow angles shown in , in particular for coke oven gas, are preferably less than 30°, more particularly less than 10°, in each case relative to the z-axis. The inflow angles for the other inlets 17 , 18 can also be realized analogously.

[0153] The distances and relative positions mentioned for the respective inlets and channels may also relate in a reciprocating manner to the distances and relative positions of the respective gas flow paths / circulation flow paths, at least in the upstream portion of the subsequent mixing with the adjacent gas flow.

[0154] Figure 3 An arrangement is shown in which the inlets 16, 17 are at a higher distance from the opposite parallel brickwork wall 15 at the same x-coordinate (x1=x2). The ratio y1:y2 is in the range of 25% to 30% and is therefore relatively high. In this case, y1 is greater than 50 mm. In particular, with this arrangement, the advantage of a flexible compensation of pressure losses can also be ensured.

[0155] Figure 3 In particular, the advantageously adjustable inlet cross sections of the two openings (gas and air) are shown. This not only enables optimization of the internal energy distribution, but also enables process engineering changes, including in particular those related to:

[0156] - Relatively high pressure loss in the heating flue (e.g. in summer): the slider opens to minimize the pressure loss;

[0157] - regulation of pressure losses and flows, in particular in order to adjust the output capacity of the plant (in particular according to the required coke production);

[0158] - Regulation of pressure loss and flow rate, in particular in order to adapt the operating parameters to the raw material (adaptation to the so-called coal basis), e.g. higher gas requirements in the case of increasing water content.

[0159] For all exemplary embodiments shown, the inner angles between the walls can also have a radius or be rounded, not only for reasons of stability but also in particular in the form of so-called gluing. The dimensional ratios and dimensions according to the invention have nothing to do with such rounding; instead, they relate to the distances between parallel walls or at least approximately parallel wall sections, in particular to the respective maximum distances in the cross-sectional plane under consideration.

[0160] Figure 3 An arrangement is shown in which the air inlet 16 and the mixed gas inlet 17 completely overlap in the x-direction, wherein the inlets are arranged without an x-offset and have at least approximately the same x-length.

[0161] Figure 4 An arrangement of inlets 16, 17 at different x-coordinates (x1>x2) at a relatively high distance y1 is shown. The ratio y1:y2 is in the range of 25% to 30%. In this case, y1 is much greater than 50 mm. The length y2 here has a dimension relative to the inner surface of the respective partition itself (itself), more particularly relative to the dimension of the parallel partition parts that are furthest apart, and is therefore independent of any optional protrusion 14.4 for stepped air ducting. In the case of relatively narrow partitions, in particular for reasons of stability, such a protrusion 14.4 is optionally provided. In this case, the y-dimension (depth) is, for example, in the range of 5 to 40 mm. In particular, in accordance with Figure 4 In the case of an arrangement, the advantage of great flexibility with regard to changing operating parameters can also be ensured.

[0162] Figure 4 In particular, measures are shown with regard to the size and geometry of the outlet opening. This allows not only optimization with regard to the internal energy distribution, but also process engineering changes, in particular with regard to:

[0163] - Parameter optimization, especially in terms of gas quality changes: during the service life, low-calorific mixed gas (especially with less than 4185kJ / Nm 3 Low calorific value; the typical low calorific value of mixed gas is 4185 to 5500 kJ / Nm 3 can be used temporarily or permanently;

[0164] - Varying the gas / air ratio in the base within a relatively large range has a good effect on the vertical temperature distribution; this is particularly advantageous if the furnace capacity needs to be changed, or if the heating method or coal base is changed.

[0165] Figure 4 An arrangement is shown in which the air inlet 16 completely overlaps the mixed gas inlet 17 in the x-direction.

[0166] Figure 5 An arrangement is shown in which the inlets 16, 17 are at a relatively large distance y1 at relatively distinct / significantly different x-coordinates (x1>x2), and the inlet 18 is each arranged relatively far apart centrally in the x-direction, more specifically also relatively far apart centrally at least in the y-direction. The ratio y1:y2 is in the range of 25% to 30%. In this case, y1 is greater than 50 mm. The ratio x2:x1 is, for example, in the region of 0.7. In particular, with this arrangement, the advantage of high usability in terms of parameter variation can also be ensured.

[0167] Figure 5 Measures are also shown in particular with regard to the geometry of the inlet or its design as a nozzle. This allows not only optimizations with regard to the internal energy distribution, but also process engineering changes that are particularly relevant for:

[0168] - The air openings in the base are designed as nozzles 16 (indicated by the circular cross-sectional geometry); in particular in case of access from above, from the top plate, the nozzles can be more easily accessed and interchanged than the slider bricks.

[0169] Figure 5 An arrangement is shown in which the air inlet 16 completely overlaps the mixed gas inlet 17 in the x-direction.

[0170] For all exemplary embodiments shown, the coke oven gas inlet can optionally also be integrated into the partition plate and thus be mounted together with the partition plate instead of being arranged at a distance from the partition plate in the y direction.

[0171] Figure 6 An arrangement is shown in which the inlets 16, 17 are at relatively distinct / significantly different x-coordinates (x1<x2) at a more or less maximum distance y1. The ratio y1:y2 is in the range of 25% to 30%. In this case, y1 is much greater than 50 mm. The ratio x1:x2 is in the region of, for example, 0.7. Figure 6 An exemplary embodiment, for example, in NO x With regard to the reduction and with regard to other operating parameters such as pressure loss, particularly advantageous effects can be ensured.

[0172] In accordance with Figure 6 In the case of the exemplary embodiment of FIG. 1 , the air and mixed gas inlets 16 , 17 can in particular be arranged without any overlap at all in the x-direction.

[0173] Figure 7 Shown with Figure 6An arrangement comparable to that of the embodiment of the present invention is an arrangement in which the offset between the inlets 16 and 17 is reversed (x1>x2). The ratio y1:y2 is in the range of 25% to 30%. In this case, y1 is much greater than 50 mm. The ratio x2:x1 is, for example, in the region of 0.6 or 0.5. In particular, with this arrangement, the advantage of very effective mixing of the recirculated exhaust gas with the air can be ensured.

[0174] In accordance with Figure 7 In the case of the exemplary embodiment of the invention, by the arrangement of the air inlet 16 in particular in the region of the recirculation opening 14.2 (in particular comparable x-coordinates), it is possible to influence the gas composition before it burns. In particular, the recirculated exhaust gas mixes with the air a short time after the respective recirculation opening and, more particularly, does not cause any combustion at this point. This process engineering arrangement can also be described as a primary mixing of flue gas and air. The effect of the arrangement according to the invention is that no external recirculation of flue gas and air is required; as a result, no measures are required either with regard to larger flow cross sections in the regenerator.

[0175] In accordance with Figure 7 In an exemplary embodiment of the invention, the air and mixed gas inlets 16, 17 can be arranged in particular in the X direction without any overlap at all and more particularly with respect to Figure 6 The arrangement shown is arranged asymmetrically.

[0176] For according to Figure 6 and Figure 7 According to an exemplary embodiment, slider bricks may also be provided respectively.

[0177] Figure 8 An arrangement according to the prior art is shown, in which the inlets 6, 7 are at comparable (more particularly identical) x-coordinates and have a relatively significant offset towards the x-center, more particularly in an at least approximately central x-arrangement, in which the inlet 8 is arranged at an x-coordinate in the region of the recirculation opening. The distance y1 has an average magnitude, and the ratio y1:y2 has an average magnitude. The x-coordinate of the inlets 6, 7, in particular the x-coordinate of their center point, is approximately half the absolute x-width of the respective heating duct, more particularly in the following range of the ratio of the absolute x-distance along the brickwork wall 15 to x1 or to x2: in the range of 0.4 to 0.6.

[0178] Fig. 9The illustrative arrangement of the openings of the invention is described in the context of further structural details of the furnace. The furnace partition x0 is in particular located in the range of 1000 to 1800 mm (from half furnace cavity to half furnace cavity; measured from center to center). The heating flue partition y0 is in particular located in the range of 400 to 550 mm (partition center to partition center). The partition 14 has a thickness (y-dimension), for example in the range of 130 to 170 mm. The straight brick masonry wall 15 has a thickness (x dimension), for example in the range of 70 to 130 mm.

[0179] The y length of the combustion air inlet 16 is, for example, in the range of greater than or equal to 50 mm, and the minimum distance from the nearest partition 14 is at least 50 mm. The y length of the mixed gas inlet 17 is, for example, in the range of greater than or equal to 50 mm, and the minimum distance from the nearest partition 14 is at least 50 mm. The x length of the combustion air inlet 16 is, for example, in the range of greater than or equal to 100 mm, and the minimum distance from the parallel brickwork wall 15 is at least 50 mm. The x length of the mixed gas inlet 17 is, for example, in the range of greater than or equal to 100 mm.

[0180] Fig. 10A , Fig. 10B and Fig. 10C In particular, a “forward combustion” operating mode is shown, in which pairs of recirculation channels are provided by way of example. Fig. 10A An exemplary arrangement according to the invention is described, in which the inlets 16, 17, 18 are in an opposing arrangement with respect to the further removed lower recirculation channel 14.2 (respectively the center point) such that a quadrilateral with a surface area A is opposed. The surface area is, for example, 500 cm 2 Up to 1700cm 2 In the range of 1000 cm 2 Up to 1500cm 2 within the range. Fig. 10A Also shown is the discharge plane xz14 of the partition 14. In contrast, the relevant vertices of the quadrilateral are offset inwardly to the center of the wall. Therefore, the surface area is independent of the wall thickness of the partition 14.

[0181] Fig. 10B An exemplary arrangement according to the invention is described, in which the inlets 16, 17, 18 are in an opposing arrangement with respect to the further removed lower recirculation channel 14.2 (respectively the center point) such that a quadrilateral with a surface area A is opposed. The surface area is in particular 700 cm 2 Up to 1600cm 2 The basic shape of a quadrilateral is a trapezoid.

[0182] Fig. 10CAn exemplary arrangement according to the invention is described, in which the inlets 16, 17, 18 are in an opposing arrangement with respect to the further removed lower recirculation channel 14.2 (respectively the center point) such that a quadrilateral with a surface area A is opposed. The surface area is in particular 500 cm 2 Up to 1400cm 2 within the range.

[0183] It has been found that for the above-described "forward combustion" furnace configuration, at 1100 to 1500 cm 2 A surface area A within a range may be particularly advantageous. Depending on the specific furnace design (size, output), an advantageous range from 200 cm² to 2000 cm² can be defined for the surface area A, particularly preferably 500 cm² to 1500 cm², more preferably 700 cm² to 1500 cm², in particular in the case of relatively large furnaces with a furnace chamber height of more than seven (7) meters, in other words in the case of a height of more than 7 meters, which has become customary for many applications in recent years.

[0184] Fig.11 and 11a The illustrative arrangement according to the invention is described with reference to a furnace design with only a lower recirculation channel, more specifically with so-called "back-to-back" heating. The arrangement of the inlets 16, 17, 18 relative to each other and to the (single) lower recirculation channel 14.2 (in each case the center point) is such that quadrilaterals with a surface area A are opposed. The surface area is, for example, from 300 cm 2 Up to 1300cm 2 In the range from 800 cm 2 Up to 1300cm 2 within the range.

[0185] It has been found that in the case of such a "back-to-back" configuration, a surface area A in the range of 1000 to 1250 cm² can be particularly advantageous. Depending on the individual furnace design (size, output), a favorable range of from 50 cm² to 1800 cm² can be defined for the surface area A, particularly preferably 300 cm² to 1300 cm², more preferably 500 cm² to 1300 cm², in particular in the case of relatively large furnaces with a furnace chamber height of more than 7 meters.

[0186] exist Fig. 10A , 10B , 10C, Fig.11 and Fig.11a In the case of the arrangement shown, the triangle can also be selectively opposed, in particular in the case where the rich gas inlet 18 is arranged in a connecting line from one of the other inlets 16, 17 to the center point of the recirculation channel 14.2 (see in this respect in particular Fig.11 ), or in the case where the inlet 16 is arranged on the connecting line between the inlet 17 and the recirculation channel 14.2. In particular, Fig.11a 1 shows an inclined, more particularly unequal, arrangement of the inlets 16 and 17 relative to a straight line G extending between the partitions 14 and parallel to the brickwork wall 15. Fig.11 The embodiments are different, according to Fig.11a The inlets 16, 17 are no longer designed to be parallel to each other, in particular their center points are located on the aforementioned straight line G. This means that the inlet 17, more particularly its center point, is arranged (constructed) on the aforementioned straight line G, while the inlet 16, more particularly its center point, is designed offset relative to the straight line G in the direction of the recirculation channel 14.2, or vice versa.

[0187] exist Fig. 10A , 10B , 10C, Fig.11 and Fig.11a In the arrangement shown, the geometric center points of the inlet of the corresponding heating flue and the inlet of at least one lower coupling channel, more particularly, the geometric center point of one of the multiple lower coupling channels further removed relative to the combustion air inlet and the mixed gas inlet, define a quadrilateral arrangement, the surface area of ​​which in the plan view is at least 50 cm², preferably at least 200 cm² or at least 300 cm² or at least 500 cm² or at least 700 cm².

[0188] With the above arrangement, the vertical position of the inlet may be varied upward or downward relative to the burner plane, as generally described above.

[0189] Fig.12 The relative arrangement of the mixed gas inlet 17 with respect to the combustion air inlet 16 according to the prior art is described. The exchange section B produced between the two adjacent inlets 16, 17 is arranged orthogonally to the transverse connection between these inlets in the sense of a contact surface with a fluid effect between two different types of gases or gas mixtures. It has been found that such an arrangement with a relatively small y distance and a relatively large exchange area leads to a significant mixing even at a short distance above the inlet, the effect of which is that high temperatures (excessively high maximum temperatures) are established and it is impossible or only possible to prevent harmful high levels of NO by countermeasures. x emission.

[0190] Fig.13A FIG. 1 shows the relative arrangement of the mixed gas inlet 17 with respect to the combustion air inlet 16 according to one of the measures of the present invention. Fig.12 The inlets completely overlap and are constructed with the same magnitude at least in the x-direction. However, the distance in the y-direction is significantly greater than Fig.12 The distance in the arrangement of , the effect is that the mixing of air and mixed gas (in time and / or relative to the vertical direction) can be delayed and / or less significant mixing occurs. In this arrangement, a relatively large exchange area is not a disadvantage.

[0191] Fig. 13B An arrangement is shown in which the commutation regions or commutation sections B are reduced in size due to the lateral x offset. Here, a commutation section B orthogonal to the lateral connection between the inlets is also shown by way of example. The inlets overlap only very slightly or, optionally, not at all. The size of the y distance is dependent on the Fig.13A It has been found that by this combination of measures the mixing of air and mixed gas can be significantly delayed and a very favorable temperature distribution can be ensured, in particular at the height of the heating duct and optionally also at other dimensions of the heating duct. x emission.

[0192] Fig.14 , Fig.15 , Fig.16 , Fig.17 , Fig.18 and Fig.19 Each shows an exemplary embodiment of a double heating flue 13 of a coke oven plant according to the invention. Fig.14 and Fig.15 The differential heat exchanger 5.6 is schematically shown with a single opening 5.61 through which the gas can circulate in the head region of the heating duct. The differential heat exchanger 5.6 is separated from the corresponding double heating duct 13 by a (middle) top plate 5.7. The differential heat exchanger 5.6 is independent of the circulating flow 9. For the sake of clarity, only the Fig.14 Schematically shown in FIG. 3 is a central part or a central part region 30 and an adjacent heat storage region 40. However, these regions can also be replaced by Fig.15 , Fig.16 , Fig.17 , Fig.18 and Fig.19An exemplary embodiment of the present invention. In this case, the central section area 30 is formed at least sectionally below the burner plane 5.4, more particularly below the base or base area 5.4 of the dual heating flue 13 or the corresponding duct. In the central section area 30, the gas is introduced and the volume flow rate is adjusted. The coupling passage 20 extends at least sectionally in the central section area 30 and has an inlet opening 21 and an outlet opening 22. The inlet 21 is formed in the base area 5.4 of the exhaust gas-guiding, downwardly flowing heating duct 12 so as to convey the recirculated exhaust gas G4 from the exhaust gas-guiding, downwardly flowing heating duct 12 through the coupling duct 20 and via the outlet 22 into the gas combustion heating duct 11. In this case, the recirculated exhaust gas G4 is advantageously introduced into the gas combustion heating duct 11 in a vertical direction and does not need to be first turned from a substantially horizontal direction to a vertical direction as in the prior art (see Figure 1G ).

[0193] like Fig.14 An exemplary embodiment of Fig.18 An exemplary embodiment of Fig.19 As shown in the exemplary embodiment of the dual heating duct 13, the dual heating duct 13 has only an upper coupling channel 14.2, which extends through the coupling partition 14. The lower coupling channel 14.2 required in order to enable the recirculation gas G4 to be recirculated is formed here by the coupling duct 20. This means that the coupling partition 14 is designed so that it is in contact with the base 5.4 of the dual heating flue 13, so that no coupling channel 14.2 is formed between the base 5.4 and the coupling partition 14. The coupling partition 14 also has no further openings or channels serving as coupling channels 14.2, and therefore only a single circulation flow 9 is used for the purpose of recirculating the exhaust gas G4. In the base region 5.4 of the respective heating duct 11, 12, in addition to the gas inlets G1 and G1a and the gas outlet G6 already fully described above, there is also at least one gas inlet for the staged air G5, or, as Fig.19 As shown, in the region of the partition wall 14a, or as Fig.18 As shown, in the region of the coupling partition 14 there are at least two gas inlets for the stage gas G5 and at least one additional gas outlet for the exhaust gas G6 .

[0194] and Fig.14 The exemplary embodiments are different. Fig.15The exemplary embodiment of has not one but three coupling channels 14.2, which are formed in the region of the coupling partition 14 and in addition to the coupling duct 20, which can be interpreted as the lowermost coupling channel. Through these channels, the recirculation gas G4 can be recirculated or recirculated in the double heating flue 13 in two circulation flows 9, namely an inner circulation flow and an outer circulation flow.

[0195] and Fig.14 and Fig.15 Compared to the exemplary embodiment, Fig.16 and 17 The exemplary embodiment of does not have any differential heat sink. Fig.16 In the exemplary embodiment of the present invention, there are three coupling channels 14.2, wherein one of these coupling channels 14.2 is formed by a coupling duct 20, which again represents the lowest coupling channel 14.2. Thus, there is an upper coupling channel 14.2 between the coupling baffle 14 and the ceiling 5.8 of the dual heating flue 13, and there is a lower coupling channel 14.2 between the coupling baffle 14 and the base 5.4 of the dual heating flue 13. An additional gas outlet for removing the exhaust gas G6 is provided in the coupling baffle 14.

[0196] Fig.17 The exemplary embodiment shown is substantially similar to Fig.15 However, in Fig.17 In the figure, a plurality of - in particular two - stepped air ducts or stepped air duct outlets 4.2 arranged one above the other in the vertical direction (z direction) are shown, which introduce the stepped air G5 into the gas combustion heating duct 11. It is also conceivable to form more than two stepped air ducts. In addition, an additional outlet G6 for the exhaust gas is formed in the dividing partition 14a of the exhaust gas conducting heating duct 12.

[0197] Reference numerals list:

[0198] 1 Coke ovens, more particularly horizontal chamber ovens

[0199] 2 Furnace chamber with coal charge

[0200] 3. Brick wall

[0201] 4 Coupling bulkheads or bonding walls

[0202] 4a Dividing partition without passage

[0203] 4.1 Ducts in bulkheads or stepped air ducts

[0204] 4.2 Combustion stages or stepped inlets or outlets at the air ducts from / to the heating ducts

[0205] 4.3 Wall surface

[0206] 4.4 Channel coupling the two heating ducts (or exhaust gas reversal point or heating gas reversal point)

[0207] 5. Double heating flues (two vertical heating flues arranged in pairs)

[0208] 5.1 Combustion heating pipe (vertical heating flue)

[0209] 5.2 Exhaust gas guiding heating duct (vertical heating flue)

[0210] 5.3 Inner wall

[0211] 5.4 Burner plane or base of heating duct / base area

[0212] 5.6 Differential Heater

[0213] 5.61 Single opening in a differential thermostat

[0214] 5.7 (Middle) Top plate of heating pipe

[0215] 5.8 Top Plate

[0216] 6 (First) Combustion air inlet, more particularly for coke oven gas heating

[0217] 7 Additional inlet for combustion air or mixed gas heating

[0218] 8 Coke oven gas inlet or coke oven gas nozzle

[0219] 9 Circulation

[0220] 10 Coke oven plant, more particularly with a horizontal chamber oven

[0221] 10.2 Furnace cavity

[0222] 11 Combustion heating pipe (vertical heating flue)

[0223] 11.1 Inner wall

[0224] 12 Exhaust gas guide heating duct (vertical heating flue)

[0225] 13 Double heating flues (two vertical heating flues arranged in pairs)

[0226] 14 Partitions or bonding walls

[0227] 14a Dividing partition without passage

[0228] 14.1 Ducts in bulkheads or stepped air ducts

[0229] 14.11 Combustion stage or stage air inlet or outlet at staged ducts from or to heating ducts

[0230] 14.2 Coupling channel for coupling two heating pipes

[0231] 14.3 The inner surface of the brick masonry wall

[0232] 14.4 Protrusions for stepped air ducts

[0233] 15 Brick wall

[0234] 15.1 Inner surface of the brick masonry wall

[0235] 16 (First) Combustion air inlet or air inlet, more particularly for coke oven gas heating

[0236] 17 Additional combustion air inlet or mixed gas inlet, more particularly for mixed gas heating

[0237] 18 Coke oven gas inlet or coke oven gas nozzle

[0238] 19 Sliding Bricks

[0239] 20 Coupling pipe

[0240] 21 Entrance opening

[0241] 22 Exit opening

[0242] 30 Center section area

[0243] 40 Heat storage area

[0244] A Surface area of ​​a polygonal arrangement (triangle or quadrilateral)

[0245] B. Commutation section

[0246] E The distance between the differential heat detector and the channel

[0247] G1 Heating gas or combustion air

[0248] G1a Coke oven gas

[0249] G1b Mixed gas

[0250] G4 Recirculated exhaust gas

[0251] G5 Staged gas or staged air from the combustion stage

[0252] G6 Exhaust

[0253] GP1 Inflow path or flow path for introducing at least one gas via an inlet

[0254] GP4 Flow path for recirculated exhaust / flue gas

[0255] GP5 Stepped gas flow path

[0256] M The central longitudinal axis of the corresponding heating pipe

[0257] T1 Nozzle brick temperature

[0258] T2 (gas) temperature in heating flue / heating duct

[0259] T3 Temperature in the furnace chamber

[0260] x Horizontal direction (width or length; longitudinal length of the bonded wall)

[0261] x0 Furnace partition

[0262] x1 Distance between the combustion air inlet and the opposite brick masonry wall

[0263] x2 Distance between the mixed gas inlet and the opposite brick masonry wall

[0264] xz14 discharge plane, partition

[0265] y Depth or horizontal spray direction (along the longitudinal length of the brickwork wall)

[0266] y0 Heating flue partition

[0267] y1 Distance between the facing edges of the combustion air inlet and the mixed gas inlet

[0268] y2 Distance from the inner edge of the partition

[0269] z vertical direction (vertical axis)

Claims

1. A coke oven plant (10) for producing coke by coking coal or a coal mixture, the coking being carried out at least by heating with a mixed gas and also with intermittent coke oven gas, wherein: The coke oven device is configured to minimize the emission of nitrogen oxides by means of an internal thermal energy balance of steel plant inherent gases and coke oven inherent gases, the coke oven device having a plurality of double heating chimneys (13), each of the double heating chimneys (13) having a gas combustion heating pipe (11) and a heating pipe (12) for guiding exhaust gas and flowing downwards, the heating pipes being bounded in pairs by partitions (14) and separated from the corresponding oven chamber (10.2) by two mutually opposite parallel brick masonry walls (15), wherein the heating pipes are fluidically coupled to each other in pairs by means of at least one upper coupling channel (14.2) and also by means of at least one lower coupling channel for internal exhaust gas recirculation on at least one circulation flow path, wherein at least one inlet of the following groups is respectively arranged in the lower region on the base (5.4) of the double heating chimneys: a coke oven gas inlet (18), a combustion air inlet (16), a mixed gas inlet (17); Characterized in that, at the base (5.4) of the dual heating flue, the ratio y1:y2 of the distance y1 between the facing edges of the combustion air inlet (16) and the mixed gas inlet (17) to the distance y2 of the inner edge of the partition (14) of the corresponding heating pipe is at least 10%, wherein the distance y1 between the facing edges of the combustion air inlet (16) and the mixed gas inlet (17) is at least 50 mm, Wherein, at least one of the combustion air inlet and the mixed gas inlet is eccentrically arranged at an x ​​distance greater than 0.7 times the absolute x length of the heating pipe between the opposite parallel brickwork walls (15).

2. The coke oven device according to claim 1, wherein: The distance y1 is at least 100 mm; and / or wherein the ratio y1:y2 is at least 25%.

3. The coke oven device according to any one of claims 1 to 2, wherein: The geometric center points of the inlet of the dual heating flue and the inlet of the at least one lower coupling channel define a triangular or quadrilateral arrangement, the surface area (A) of the triangular or quadrilateral arrangement in the plan view is at least 50 cm² and / or wherein the surface area (A) of the triangular or quadrilateral arrangement in the plan view is not greater than 2000 cm².

4. The coke oven device according to claim 3, wherein: The surface area (A) of the triangle or quadrilateral arranged in a plan view is at least 200 cm²; and / or wherein the surface area (A) of the triangle or quadrilateral arranged in a plan view is not greater than 1800 cm².

5. The coke oven device according to claim 3, wherein: The surface area (A) of the triangle or quadrilateral arranged in a plan view is at least 300 cm²; and / or wherein the surface area (A) of the triangle or quadrilateral arranged in a plan view is not greater than 1500 cm².

6. The coke oven device according to claim 3, wherein: The surface area (A) of the triangle or quadrilateral arranged in a plan view is at least 500 cm²; and / or wherein the surface area (A) of the triangle or quadrilateral arranged in a plan view is not greater than 1300 cm².

7. The coke oven device according to claim 3, wherein: The surface area (A) of the triangular or quadrilateral arrangement in plan view is at least 700 cm².

8. The coke oven device according to claim 3, wherein: The surface area (A) of the triangle or quadrilateral arrangement in a plan view is between 1000 cm² and 1350 cm².

9. The coke oven device according to claim 3, wherein: The surface area (A) of the triangle or quadrilateral arrangement in a plan view is between 1000 cm² and 1300 cm².

10. The coke oven device according to any one of claims 4 to 9, wherein: The inlet of the dual heating flue and the geometric center point of one of the plurality of lower coupling channels further removed relative to the combustion air inlet and the mixed gas inlet define the triangular or quadrilateral arrangement.

11. The coke oven device according to any one of claims 1 to 2, wherein: At the base of the dual-heating flue, the cross-sectional surface area of ​​the combustion air inlet (16) and / or the mixed gas inlet (17) is at least 30 cm²; and / or wherein the cross-sectional surface area of ​​the combustion air inlet (16) and / or the mixed gas inlet (17) is not greater than 500 cm²; and / or wherein the cross-sectional geometry of the combustion air inlet (16) and / or the mixed gas inlet (17) is rectangular, elliptical or circular.

12. The coke oven plant according to claim 11, wherein: At the base of the dual heating flue, the cross-sectional surface area of ​​the combustion air inlet (16) and / or the mixed gas inlet (17) is at least 50 cm²; and / or wherein, The cross-sectional surface area of ​​the combustion air inlet (16) and / or the mixed gas inlet (17) is not greater than 400 cm².

13. The coke oven device according to any one of claims 1 to 2, wherein: At the base of the respective dual heating duct, the cross-sectional area of ​​the combustion air inlet (16) and / or the mixed gas inlet (17) is designed to be adjustable in terms of geometry and / or size.

14. The coke oven plant according to claim 13, wherein: At the base of the corresponding dual heating chimney, the cross-sectional area of ​​the combustion air inlet (16) and / or the mixed gas inlet (17) is configured to be adjustable by means of at least one movable sliding brick and / or by means of at least one interchangeable / removable nozzle.

15. The coke oven device according to any one of claims 1 to 2, wherein: At least one upper coupling channel (14.2) coupling two heating pipes of a double heating flue in the upper region is arranged for reciprocating gas transport, wherein the upper coupling channel (14.2) has a cross-sectional surface area of ​​at least 250 cm²; and / or wherein the heating pipes are fluidically coupled to each other in pairs by means of at least two lower coupling channels, wherein the combustion air inlet (16) is arranged at the same x position as the corresponding lower coupling channel; and / or wherein at least two lower coupling channels are arranged.

16. The coke oven plant according to claim 15, wherein: The cross-sectional surface area of ​​the upper coupling channel (14.2) is not greater than 1200 cm²; and / or wherein the heating pipes are fluidically coupled to each other in pairs by means of at least two lower coupling channels, wherein the respective center points of the combustion air inlet and the corresponding channel are arranged at the same x-coordinate; and / or wherein at least two lower coupling channels are provided, which are arranged in pairs at the same vertical position.

17. The coke oven plant according to claim 15, wherein: The cross-sectional surface area of ​​the upper coupling channel (14.2) is no greater than 1000 cm².

18. The coke oven device according to any one of claims 1 to 2, wherein: The combustion air inlet (16) and the mixed gas inlet (17) are offset along the x direction relative to the opposite longitudinal brick masonry wall (15); and / or wherein, at the base of the double heating flue, the edges of the combustion air inlet (16) and the mixed gas inlet (17) facing the longitudinal brick masonry wall (15) are arranged at different distances relative to at least one of the two opposite longitudinal brick masonry walls (15) of the corresponding double heating flue; and / or wherein the ratio x1:y1 or x2:y1 of the distance x1 between the combustion air inlet (16) and the opposite longitudinal brick masonry wall (15) and / or the distance x2 between the mixed gas inlet (17) and the opposite longitudinal brick masonry wall (15) to the distance y1 is at least 90% and / or not more than 290%.

19. The coke oven plant according to claim 18, wherein: The combustion air inlet (16) and the mixed gas inlet (17) are offset along the x direction relative to the opposite brick masonry wall (15); and / or wherein, at the base of the double heating flue, the edges of the combustion air inlet (16) and the mixed gas inlet (17) facing the brick masonry wall (15) are arranged at different distances relative to at least one of the two opposite brick masonry walls (15) of the corresponding double heating flue, and have a distance difference of at least 10 mm or at least 50 mm; and / or wherein the ratio x1:y1 or x2:y1 of the distance x1 between the combustion air inlet (16) and the opposite brick masonry wall (15) and / or the distance x2 between the mixed gas inlet (17) and the opposite brick masonry wall (15) to the distance y1 is between 200% and 250%.

20. The coke oven device according to any one of claims 1 to 2, wherein: The combustion air inlet (16) is arranged closer to the opposing parallel brickwork walls (15) than the mixed gas inlet (17), or vice versa, with a distance difference of at least 10 mm in a central area centered between the opposing parallel brickwork walls (15).

21. The coke oven plant according to claim 20, wherein: The combustion air inlet (16) is arranged with a distance difference of at least 50 mm in a central area centered between the opposing parallel brickwork walls (15).

22. A coke oven device (10) for producing coke by coking coal, the coking being carried out at least by mixed gas heating, the coke oven device minimising the emission of nitrogen oxides by internal heat energy compensation, the coke oven device comprising a plurality of double heating flues (13) with paired heating pipes, the pipes being bounded in pairs by partitions (14) and separated by two parallel brick masonry walls (15) facing each other, wherein: At least one inlet from the following group is arranged on the base (5.4) of the heating pipe: a coke oven gas inlet (18), a combustion air inlet (16), and a mixed gas inlet (17); wherein the heating pipes are fluidically coupled to each other in pairs by means of at least one upper coupling channel and also by means of at least two lower coupling channels, respectively for internal exhaust gas recirculation on at least one circulation flow path, wherein, on the base (5.4) of the heating pipe, the ratio y1:y2 of the distance y1 between the facing edges of the combustion air inlet (16) and the mixed gas inlet (17) to the distance y2 of the inner edge of the partition (14) is at least 10%, wherein the distance y1 between the facing edges of the combustion air inlet (16) and the mixed gas inlet (17) is at least 50 mm, wherein at least one of the combustion air inlet and the mixed gas inlet is eccentrically arranged at an x ​​distance greater than 0.7 times the absolute x length of the heating pipe between the opposite parallel brickwork walls (15); And wherein the heating ducts are fluidically coupled to one another in pairs by means of at least two lower coupling channels, wherein the combustion air inlet (16) is arranged at the same x position as the corresponding lower coupling channel.

23. The coke oven plant according to claim 22, wherein: The center points of the combustion air inlet and the corresponding lower coupling channel are arranged at the same x-coordinate.

24. A coke oven apparatus (10) for producing coke by coking coal, wherein: The coke oven device has at least mixed gas heating and minimizes nitrogen oxide emissions by internal thermal energy compensation, the coke oven device comprises a plurality of double heating flues (13) with heating pipes, the heating pipes are delimited in pairs by partitions (14) and separated by two parallel brick masonry walls (15) opposite to each other, wherein the heating pipes are fluidically coupled to each other in pairs by means of at least one upper coupling channel and also by means of at least one lower coupling channel for internal exhaust gas recirculation on at least one circulation flow path, wherein at least one inlet of the following group is arranged in the lower region on the base (5.4) of the heating pipes: a coke oven gas inlet (18), a combustion air inlet (16), a mixed gas inlet (17); wherein, on the base (5.4) of the heating pipe, a ratio y1:y2 of a distance y1 between facing edges of the combustion air inlet (16) and the mixed gas inlet (17) to a distance y2 from an inner edge of the partition (14) is at least 10%, wherein the distance y1 between facing edges of the combustion air inlet (16) and the mixed gas inlet (17) is at least 50 mm, wherein at least one of the combustion air inlet and the mixed gas inlet is eccentrically arranged at an x ​​distance greater than 0.7 times the absolute x length of the heating pipe between the opposite parallel brick masonry walls (15); wherein the combustion air inlet (16) and the mixed gas inlet (17) are offset in the x direction relative to the opposite parallel brick masonry walls (15).

25. The coke oven plant according to claim 24, wherein: The distance y1 is at least 100 mm.

26. The coke oven plant according to claim 24, wherein: The distance y1 is at least 150 mm.

27. A method for operating a coke oven plant according to any one of claims 1 to 26, the coke oven plant (10) being used for producing coke by coking coal or a coal mixture, wherein: The coke oven device is optimized to minimize nitrogen oxide emissions by internal heat energy compensation with the help of steel plant natural gas and coke oven natural gas through measures within the coke oven device, wherein the coke oven device has at least mixed gas heating and also has intermittent coke oven gas heating, wherein in the double heating flue (13) of the coke oven device, an internal exhaust gas recirculation is established on at least one circulation flow path around the partition (14) by means of at least one coupling channel (14.2) through the partition, the coke oven device has a combustion heating duct (11) and an exhaust gas-conducting heating duct (12), wherein at least two gases from the following group are received in the lower region on the base (5.4) of the double heating flue: coke oven gas (G1a), combustion air (G1), mixed gas (G1b), wherein the group of gases received includes at least two gases, combustion air (G1) and mixed gas (G1b); Characterized in that, at the base (5.4) of the double heating flue, the combustion air and the mixed gas are received on flow paths at a distance y1 relative to each other, the ratio y1:y2 of the distance y1 to the distance y2 of the inner edge of the partition (14) of the corresponding heating pipe being at least 10%; wherein the distance y1 of the two received flow paths is at least 50 mm, Therein, the combustion air and / or the mixed gas is received eccentrically at an x ​​distance which is greater than 0.7 times the absolute x length of the heating duct between the opposing parallel brickwork walls (15).

28. The method according to claim 27, wherein: At the base of the dual heating chimney, the cross-sectional area of ​​the combustion air inlet (16) and / or the mixed gas inlet (17) is adjusted in terms of geometry and / or size.

29. The method according to claim 28, wherein: At the base of the dual heating chimney, the cross-sectional area of ​​the combustion air inlet (16) and / or the mixed gas inlet (17) is adjusted in terms of geometry and / or size by at least one sliding brick.

30. The method according to any one of claims 27 to 29, wherein: The flame temperature of the mixed gas heating does not exceed 1700°C; and / or wherein, The air flow in the heating flue is established so as to minimize the ratio of the flame temperature to the nozzle brick temperature.

31. The method according to claim 30, wherein: The flame temperature of the mixed gas heating does not exceed 1600°C.

32. The method according to claim 31, wherein: The flame temperature of the mixed gas heating does not exceed 1500°C.

33. The method of claim 30, wherein: The flame temperature of the mixed gas heating is at least 1300°C at the nozzle brick temperature.

34. The method of claim 33, wherein: The flame temperature for heating by the mixed gas is at least 1320°C at the nozzle brick temperature.

35. The method according to any one of claims 27 to 29, wherein: The received gas and / or the circulating gas is directed or guided in a horizontal direction; and / or wherein the received gas is received by means of inlets at different vertical levels.

36. The method of claim 35, wherein: The received gases and / or circulating gases are directed or guided at multiple vertical levels by means of baffle internals or baffles or bricks or shields; and / or wherein the received gases are received using a mixed gas inlet at a vertical level above the combustion air inlet.

37. The method of claim 36, wherein: The received gas and / or the circulating gas is directed or guided at multiple vertical levels by means of baffle inner parts or baffles or bricks or shields made of refractory materials respectively; and / or wherein the received gas is received by means of the mixed gas inlet arranged on the base above the base of the dual heating flue.

38. A method for operating a coke oven plant according to any one of claims 1 to 26, the coke oven plant (10) being used for producing coke by coking coal or a coal mixture, wherein: The coke oven device is optimized to minimize nitrogen oxide emissions by internal heat energy compensation with the help of steel plant natural gas and coke oven natural gas through measures within the coke oven device, wherein the coke oven device has at least mixed gas heating and also has intermittent coke oven gas heating, wherein in a double heating chimney (13) of the coke oven device (10), an internal exhaust gas recirculation is established on at least one circulation flow path around the partition (14) by means of at least one coupling channel (14.2) through the partition, the double heating chimney has a heating pipe for combustion (11) and a heating pipe for guiding exhaust gas (12), wherein at least two gases from the following group are received in a lower area on the base (5.4) of the double heating chimney: coke oven gas (G1a), combustion air (G1), mixed gas (G1b), wherein the gas group received includes at least two gases, combustion air (G1) and mixed gas (G1b); Characterized in that the recirculated exhaust gas (G4) from the exhaust gas recirculation flows through a coupling pipe (20), which extends at least in sections in a central section area (30) located in pairs below the heating pipe and connects the combustion heating pipe (11) to a heating pipe (12) that guides the exhaust gas and flows downward, and the flow causes the recirculated exhaust gas (G4) to be introduced into the gas combustion heating pipe (11) in a vertical direction.

39. Use of a combustion air inlet and a mixed gas inlet in a coke oven plant (10) according to any one of claims 1 to 26, the coke oven plant (10) comprising a plurality of double heating flues (13) each having two heating ducts for producing coke by coking coal or a coal mixture, wherein: The coke oven device has at least mixed gas heating and also has intermittent coke oven gas heating, wherein, in the double heating flue (13), internal exhaust gas recirculation is established on at least one circulation flow path by means of at least one coupling channel (14.2), wherein, in order to minimize the emission of nitrogen oxides by internal thermal energy compensation, the inlet is arranged so that the ratio y1:y2 of the distance y1 between the facing edges of the combustion air inlet (16) and the mixed gas inlet (17) and the distance y2 to the inner edge of the partition (14) of the corresponding heating pipe is 10%, wherein the distance y1 between the facing edges of the combustion air inlet (16) and the mixed gas inlet (17) is at least 50 mm.

40. Use of combustion air and mixed gas in a coke oven plant (10) according to any one of claims 1 to 26 for minimizing the emission of nitrogen oxides by internal thermal energy compensation, wherein: In a corresponding double heating flue (13), an internal exhaust gas recirculation is established on at least one circulation flow path by means of at least one coupling channel (14.2), wherein the combustion air and the mixed gas are admitted at a distance of at least 50 mm relative to each other, the ratio y1:y2 of the distance y1 between the combustion air inlet (16) and the mixed gas inlet (17) to the distance y2 of the inner edge of the partition (14) of the corresponding heating duct is at least 10%, and the combustion air and the mixed gas are admitted at a nozzle brick temperature of at least 1300°C at a flame temperature heated with a mixed gas of not more than 1700°C.

41. The use according to claim 40, characterized in that The combustion air and the mixed gas are admitted at a flame temperature heated with the mixed gas not exceeding 1600°C and at a nozzle brick temperature of at least 1320°C.

42. The use according to any one of claims 40-41, characterized in that The combustion air and the mixed gas are admitted at a flame temperature heated by the mixed gas not exceeding 1500°C.

Images