BE1030366B1 - Method for operating a burner of a rotary kiln - Google Patents

Abstract

The present invention relates to a method for operating a burner (14) of a rotary kiln (10), wherein the gas streams supplied to the rotary kiln (10) comprise in total more than 50% by volume of oxygen, the burner (14) having a burner mouth (20). , from which a fuel-gas mixture is released and at least one state variable of the burner flame (16), in particular the ignition gap (18), the flame shape, the flame length and / or the flame width, is determined, the flow speed, the quantity and / or the pulse of the fuel-gas mixture and/or the fuel properties are controlled/regulated depending on the determined state variable. The invention also relates to a rotary kiln (10) for burning raw meal into cement clinker, having a combustion zone formed within the rotary kiln (10), a burner (14) with a burner mouth (20) for releasing a fuel-gas mixture into the combustion zone, a measuring device ( 22), which is designed and arranged in such a way that it determines at least one state variable of the burner flame (16), in particular the ignition gap (18), the flame length and/or the flame width, the rotary kiln (10) having a control/regulating device , which is designed in such a way that it controls/regulates the flow velocity, the quantity and/or the momentum of the fuel-gas mixture and/or the fuel properties depending on the determined state variable.

Description

' BE2022/5195

Method for operating a burner of a rotary kiln

The invention relates to a method for operating a rotary kiln, in particular a burner within the rotary kiln, wherein the rotary kiln is operated with an oxygen-rich gas.

Rotary kilns are commonly used in the cement and mineral industries and are used, for example, to burn preheated raw cement meal

Cement clinker.

It is known from the prior art to use oxygen-containing gas for the combustion of carbon-containing fuels in the rotary kiln or the calciner

To introduce cement manufacturing plant. In order to reduce the amount of exhaust gas and to be able to dispense with complex cleaning processes, it is known, for example from DE 10 2018 206 673 A1, to use a combustion gas that is as rich in oxygen as possible, so that the CO2 content in the exhaust gas is high and storage of the

CO2 or a separation in the exhaust gas stream is facilitated. DE 10 2018 206 673 A1 discloses introducing an oxygen-rich gas into the cooler inlet area

Preheating the gas and cooling the clinker.

When using oxygen-enriched combustion gases that have a high oxygen content of at least 30% to 100%, very high temperatures can arise in the furnace. If these high temperatures occur over a longer period of time or permanently in the area near the wall of the oven, damage to the inner wall of the oven can result. There is also that

There is a risk that very high temperatures will develop on the burner and, in particular, the burner mouth will be damaged.

Based on this, it is the object of the present invention to provide a method for

To provide operation of a rotary kiln, in particular a burner, ensuring safe operation of the rotary kiln and at the same time obtaining an exhaust gas with a high CO2 content.

° BE2022/5195

This object is achieved according to the invention by a method with the features of independent method claim 1 and by a rotary kiln according to independent claim 10. Advantageous further training results from the dependent requirements.

A method for operating a rotary kiln, in particular a burner

Rotary kiln, according to a first aspect, includes that the gas streams supplied to the rotary kiln consist in total of more than 50% by volume of oxygen, preferably an oxygen-rich atmosphere within the rotary kiln with a

Oxygen content of more than 30 vol%, preferably more than 50 vol%, in particular more than 75 vol% is formed. The oxygen-rich atmosphere is, in particular, the average oxygen content within the entire atmosphere

Rotary kiln, where local areas with an oxygen content of less than 50Vol% can occur. The burner has a burner mouth from which a

Fuel-gas mixture is discharged into the interior of the rotary kiln, in particular the combustion chamber, and at least one state variable of the burner flame, in particular the ignition distance, the flame shape, the flame length and / or the

Flame width is determined. The flow speed, the quantity and/or the

Impulse of the fuel-gas mixture and/or the fuel properties are in

Dependency and preferably controlled/regulated to influence the determined state variable.

The fuel properties are preferably fuel moisture,

Fuel composition, the calorific value and/or the grain size of the fuel.

The furnace is in particular a rotary kiln and preferably part of one

Cement manufacturing plant, the cement manufacturing plant comprising, for example: - a preheater for preheating raw meal, - a calciner for calcining the preheated raw meal, - a rotary kiln with a burner for burning the calcined hot meal into cement clinker and - a cooler for cooling the cement clinker.

The rotary kiln includes a burner, such as a burner lance and/or a single-channel or multi-channel burner for burning the calcined hot flour

Cement clinker, wherein the rotary kiln has a combustion gas inlet for admitting 5 a combustion gas into the rotary kiln with an oxygen content of 50% to 100% by volume, in particular at least 50% by volume, preferably at least 75% by volume. The combustion gas inlet is preferably located in the furnace head, to which the cooler is connected. In particular, the combustion gas is at least partially formed from the cooler exhaust air. The burner optionally has one

Combustion gas inlet, in particular for controlling and regulating the

Flame parameters through which a combustion gas is introduced into the furnace.

This combustion gas can differ in its composition from that

Combustion gas supplied via the cooler will differ. In a special one

In this embodiment, this combustion gas has an oxygen content between 0 and 100%, in particular a maximum of 21%, preferably a maximum of 10%.

A preheater of the cement production plant preferably comprises a plurality of

Cyclone stages, each with at least one cyclone for separating solids from the gas stream. In the preheater, the raw meal fed into the top, first cyclone stage is preheated in countercurrent to the furnace exhaust gases and passes through the cyclone stages one after the other.

Between the last and the penultimate cyclone stage, the calciner is preferably arranged, which has a riser into which the raw meal is fed by means of a

Calcinator firing, is heated. In particular, the raw meal is deacidified and calcined in the calciner.

The raw meal preheated in the preheater and calcined in the calciner is then fed to the rotary kiln. The rotary kiln has in particular a rotary tube which can be rotated about its longitudinal axis and which is preferably slightly inclined in the conveying direction of the material to be burned, so that the material is moved in the conveying direction due to the rotation of the rotary tube and gravity. The furnace preferably has a material inlet at one end for admitting preheated, calcined raw meal and the material inlet at its end

* BE2022/5195 opposite end has a material outlet to let out the burned

Clinker into the cooler. At the end of the furnace on the material outlet side, a furnace head is preferably arranged, which has the burner for burning the material, in particular a fuel lance and/or a single-channel or multi-channel burner. The rotary kiln preferably has a sintering zone in which the material is at least partially melted and in particular has a temperature of 1500°C to 1900°C, preferably 1450°C to 1750°C. The sintering zone includes, for example, the furnace head and in particular a sector of the rotary kiln at the rear end, preferably the rear third of the rotary kiln in the conveying direction of the material

oven.

The oxygen-containing combustion gas is, for example, completely or partially introduced directly into the furnace head, the furnace head having, for example, a

Has combustion gas inlet. Preferably, all or part of the combustion gas is introduced into the furnace via the material outlet. For example, the combustion gas supplied to the furnace has an oxygen content of more than 30

Vol% to 75 Vol%, in particular more than 50 Vol%, preferably more than 95 Vol%. The

For example, combustion gas consists entirely of pure oxygen, in which case the oxygen content of the combustion gas is 100%. In which

Burner can be, for example, a burner lance and/or a single channel or

Act multi-channel burner. A cooler for cooling the cement clinker is preferably connected to the material outlet of the kiln.

The cooler preferably has a conveyor device for conveying the bulk material

Conveying direction through the cooling gas space. The cooling gas space is preferably in

Flow direction of the bulk material to be cooled is arranged directly behind the cooler inlet, in particular the material outlet of the kiln, so that the clinker falls from the rotary kiln into the cooling gas space and in particular the heated one

Cooling gas flow from the cooler enters the rotary kiln and at least partially

Combustion gas forms.

The burner of the rotary kiln is preferably a single burner lance and/or a single-channel or multi-channel burner with a

A plurality of pipes or channels arranged coaxially to one another. Preferably is

) BE2022/5195 the burner is attached to the wall, in particular the inner wall, of the furnace head, in particular to a static area of the rotary kiln and extends in particular in the axial direction, preferably centrally into the rotary tube of the

Rotary kiln.

The burner includes, for example, a plurality of tubes, in particular four

Pipes that are arranged coaxially to one another and have different diameters. A central tube is arranged in the middle, which forms a central channel. The

The central tube with the smallest diameter is used to transport particularly lumpy fuel, such as substitute fuels from waste or

Production residues, such as used tires. Together with the fuel, a carrier gas is passed through the central tube, which is used for the pneumatic transport of the

fuel is used. The carrier gas is in particular an oxygen-poor gas with an oxygen concentration of 0 to 30 vol%, in particular 2 to 20 vol%, preferably 10 to 15 vol%, most preferably less than 10 vol%.

The transport gas preferably has a CO2 concentration of 70 to 95% by volume, in particular 80 to 90% by volume, preferably more than 75% by volume. The remaining portion of the transport gas preferably comprises oxygen and/or water vapor and/or another inert gas component. The central tube is preferably equipped with a source of fuel, in particular lumpy substitute fuel, and a source for the

Transport gas connected.

A swirl gas tube is preferably arranged coaxially around the central tube and has a

Swirl gas channel forms. The swirl gas channel preferably serves to conduct a

Swirl gas with an oxygen content of 0 to 100% by volume, in particular 0 to 75% by volume, preferably less than 10% by volume. The swirl gas channel is preferably with a

Source for the swirl gas connected. The swirl gas pipe extends axially, for example

Direction, towards the burner mouth, out over the central tube.

The fuel pipe is preferably arranged coaxially to the swirl gas pipe, which has a

Fuel channel forms and preferably for the conduction of a fine piece

Fuel, such as coal, and the line of a carrier gas for pneumatic transport of the fuel through the fuel channel. The

Carrier gas preferably has an oxygen content of 0 to 30% by volume, in particular

° BE2022/5195 2 to 20 vol%, %, preferably less than 10 vol%. on. Preferably this has

Transport gas has a COz concentration of 70 to 95% by volume, in particular 80 to 90% by volume, preferably more than 75% by volume. The remaining portion of the transport gas preferably comprises oxygen and/or water vapor. The fuel pipe preferably extends in the axial direction, in the direction of the burner mouth, over the central pipe and out of the swirl gas pipe. The fuel channel is preferably connected to a source for the carrier gas and the particularly fine-grained fuel. Instead of the finely lumped fuel, a liquid or gaseous fuel can also be used

It is used which is fed into the combustion chamber under pressure without any portion of the transport gas.

The axial gas pipe is preferably arranged coaxially around the fuel pipe, which has a

Axial gas channel forms and is preferably used to conduct an axial gas. The

Axial gas preferably has an oxygen content of 0 to 100 vol%, in particular 0 to 75 vol%, preferably less than 10 vol%, with the axial gas channel preferably being connected to a source for the axial gas. The axial gas tube extends in particular in the axial direction, in the direction of the burner mouth

Central pipe, the fuel pipe and the swirl gas pipe out.

The fuel-gas mixture preferably comprises the carrier gas, the axial gas and/or the swirl gas, as well as a fine-grained fuel and/or a coarse-grained one

Fuel, especially a substitute fuel. The carrier gas, swirl gas and/or that

Axial gas includes exhaust gas from the rotary kiln or exhaust gas from the cement production plant that is at least partially or completely discharged from the rotary kiln.

The axial gas and the swirl gas preferably have a higher flow velocity relative to the carrier gas, so that the axial gas and the swirl gas preferably apply a swirl pulse to the mixture of fuel and carrier gas. In particular, the swirl gas pipe, in particular the burner mouth, is designed such that the swirl gas has a substantially tangential

Flow direction related to the burner axis. Preferably that is

Axial gas pipe, in particular the burner mouth, designed such that the axial gas has a substantially axial flow direction with respect to the burner axis.

' BE2022/5195

The terms taxes and rules are processes of the

Automation technology. The term rules refers to a process in which one variable, the controlled variable, is continuously recorded, with another variable, the

Reference variable, compared and influenced in the sense of an alignment with the reference variable. The term control refers to a process in which at least one input variable influences other variables as output or control variables based on the regularities inherent in the system. The term “adjusting” includes both controlling and regulating.

The ignition distance is the distance, preferably in the axial direction of the rotary kiln, between the burner mouth and the flame. In particular, the ignition distance is the smallest distance between the burner mouth and the

burner flame. The flame length is preferably the extent of the burner flame in the axial direction of the rotary kiln, whereby the flame width is the extent of the

Burner flame is in the radial direction of the rotary kiln.

According to a first embodiment, the state variable of the burner flame is compared with a limit value or limit range and, if there is a deviation from the determined one

State variable of the limit value or limit range, the flow velocity, the quantity and/or the momentum of the fuel-gas mixture and/or the

Fuel properties set. Preferably, each state variable has the

Burner flame reaches a respective limit value or a limit range. The

Limit range preferably includes a maximum value and a minimum value, whereby falling below the limit range, falling below the minimum value and that

Exceeding the limit value includes exceeding the maximum value. Such a regulation makes it possible to monitor the state variables of the

Burner flame to prevent damage to the burner.

According to a further embodiment, the ignition gap is determined and with a

Ignition distance limit or limit range is compared, whereby if the determined ignition distance deviates from the ignition distance limit or limit range, the

Fuel moisture, the grain size of the fuel, the CO2 content of the fuel

Gas mixture and / or the oxygen content of the fuel-gas mixture is increased or reduced.

° BE2022/5195

If the determined ignition distance falls below the ignition distance limit or limit range, the fuel moisture and/or the grain size of the fuel is preferably increased.

If the determined ignition distance exceeds the ignition distance limit or limit range, the fuel moisture and/or the grain size of the fuel is preferably reduced. In particular, if the ignition distance limit value or limit range is undershot, fine-grained material, such as lime powder or gypsum powder, will pass through

Burner, in particular through the fuel channel and/or the axial gas channel into the

Burning zone of the rotary kiln abandoned. This prevents the fuel from igniting near the burner mouth. It is also conceivable for one

Falling below the ignition distance limit or limit range

To increase the flow rate of the carrier gas.

According to a further embodiment, the burner has an axial gas channel through which an axial gas flows and emerges from the burner mouth in a substantially axial direction of the burner, and a swirl gas channel through which a swirl gas flows and emerges from the burner in a substantially tangential direction of the burner

burner mouth exits. The ignition gap is preferably determined and with a

Ignition distance limit or limit range is compared, whereby if the determined ignition distance deviates from the ignition distance limit or limit range, the

Flow velocity, the oxygen content and/or the CO2 content of the

Axial gas and/or the swirl gas is increased or decreased. Preferably, only axial gas flows through the axial gas channel and exclusively swirl gas flows through the swirl gas channel according to the previous description. A setting of the

Flow velocities of the axial gas and the swirl gas ensure a corresponding impulse on the mixture of fuel and carrier gas as it exits the burner mouth, so that the flame shape can be adjusted accordingly.

According to a further embodiment, the flame length is determined and with a

Flame length limit or limit range compared, whereby if the determined flame length deviates from the flame length limit or limit range

Flow velocity and/or the momentum of the fuel-gas mixture is increased or reduced. The flow rate of the fuel-gas mixture is preferably adjusted by adjusting the flow rates of the axial gas,

) BE2022/5195

Swirl gas and / or carrier gas is set, such a setting preferably ensuring optimal mixing between the fuel and the gases.

According to a further embodiment, the flame length and/or the

Flame width determined and with a flame length/flame width limit or

Limit range compared, whereby if the determined flame length or flame width deviates from the flame length/flame width limit or

Boundary area water vapor, CO2, and/or solid particles are introduced into the combustion zone. Preferably the water vapor, the CO2, and/or the

Solid particles via the burner and/or via a separate line into the

Rotary kiln, especially the combustion zone, abandoned. A task from

Water vapor, the CO2, and/or the solid particles, for example, cause one

Ignition delay and/or improved or reduced

Thermal expansion of the burner flame.

According to a further embodiment, the burner has an axial gas channel through which an axial gas flows and emerges from the burner mouth in a substantially axial direction of the burner, and a swirl gas channel through which a swirl gas flows and emerges from the burner in a substantially tangential direction of the burner

burner mouth exits. If the determined flame length deviates from that

Flame length limit or limit range is the flow velocity of the

Axial gas in the axial gas channel and the swirl gas in the swirl gas channel increases or decreases.

If the determined flame length falls below the flame length limit or

The limit region is preferably the flow velocity of the axial gas in the

Axial gas channel increases and/or the flow velocity of the swirl gas in the

Swirl gas channel reduced. If the determined flame length exceeds the

Flame length limit or limit range is preferably the

Flow velocity of the axial gas in the axial gas channel is reduced and/or the

Flow velocity of the swirl gas in the swirl gas channel is increased. The

Flow velocity of the carrier gas is preferably unchanged depending on the determined flame length.

According to a further embodiment, the exhaust gas from the rotary kiln is at least partially fed to the burner. Preferably, the exhaust gas from the rotary kiln at least partially or completely forms the carrier gas. In particular, the exhaust gas from the rotary kiln is supplied partially or completely via the burner or via a line arranged separately from the burner. The exhaust gas is, for example, at least partially exhaust gas from the cement production plant.

According to a further embodiment, the state variable of the burner flame is determined using a camera, in particular an infrared camera.

The invention also includes a rotary kiln for burning raw meal

Cement clinker having a combustion zone formed within the rotary kiln, a burner with a burner mouth for releasing a fuel

Gas mixture into the combustion zone, a measuring device which is designed and arranged such that it determines at least one state variable of the burner flame, in particular the ignition distance, the flame length and / or the flame width. The rotary kiln has a control/regulation device which is designed in such a way that it controls the flow rate, the quantity and/or the momentum of the

Controls/regulates the fuel-gas mixture and/or the fuel properties depending on the determined state variable.

The embodiments and advantages described with reference to the method for operating a burner of a rotary kiln also apply, in accordance with the device, to the rotary kiln for burning raw meal into cement clinker.

The measuring device is preferably designed in such a way that it transmits the determined data, in particular the state variables of the burner flame, to the control/regulation device. The rotary kiln preferably has one or more

A plurality of gas inlets for admitting combustion gas, in particular

oxygen, on. Preferably, the gas inlets of the rotary kiln are connected to at least one or more gas sources which have a gas with an oxygen content of more than 50% by volume. Preferably, the control/regulation device is designed in such a way that it sets an oxygen content of more than 50% by volume, in particular more than 75% by volume, preferably more than 90% by volume within the rotary kiln, in particular the combustion zone. Preferably, the oxygen content within the furnace is greater than 50% by volume overall, with individual areas having one locally

Oxygen content of less than 50Vol®% can occur.

According to one embodiment, the control/regulation device is designed such that it controls the state variable of the burner flame with a limit value or

Compares the limit range and, if the determined state variable deviates from the limit value or limit range, adjusts the flow velocity, the quantity and/or the momentum of the fuel-gas mixture and/or the fuel properties.

According to a further embodiment, the measuring device is designed in such a way that it determines the ignition gap and the control/regulation device is designed in such a way that it compares the determined ignition gap with an ignition gap limit value or limit range and, in the event of a deviation of the determined ignition gap from the ignition gap limit value or limit range, the Fuel moisture, the grain size of the fuel, the CO2 content of the fuel-gas mixture and/or the

Oxygen content of the fuel-gas mixture increased or decreased.

According to a further embodiment, the burner has an axial gas channel which is designed such that an axial gas flows through it and emerges from the burner mouth in a substantially axial direction of the burner, and wherein the burner has a swirl gas channel which is designed such that a Swirl gas flows through this and out of the burner in a substantially tangential direction

Burner mouth exits and the measuring device is designed such that it

Ignition distance determined. The open-loop and closed-loop control device is designed in such a way that if the determined ignition gap deviates from a predetermined one

Ignition distance limit or limit range, the flow velocity, the

Oxygen content and/or the CO2 content of the axial gas and/or the swirl gas increases or decreases.

According to a further embodiment, the measuring device is designed such that it determines the flame length. The control/regulation device is preferably designed in such a way that it compares the determined flame length with a

Flame length limit or limit range is compared and if the determined flame length deviates from the flame length limit or limit range

Flow velocity and/or the momentum of the fuel-gas mixture increases or decreases.

According to a further embodiment, the rotary kiln has a line for feeding water vapor, CO2, and/or solid particles into the combustion zone, whereby the

Measuring device is designed in such a way that it determines the flame length and the

Control/regulation device is designed such that it determines the determined

Flame length compares with a flame length limit or limit range and if the determined flame length deviates from the flame length limit or limit range, water vapor, CO2, and / or solid particles are introduced into the combustion zone. The rotary kiln preferably has a line separate from the burner for feeding water vapor, CO2 and/or solid particles into it

Burning zone. The line and/or the burner are preferably equipped with a source for

Water vapor, CO2, and/or solid particles are connected.

According to a further embodiment, the burner has an axial gas channel which is designed such that an axial gas flows through it and emerges from the burner mouth in a substantially axial direction of the burner. The burner has one

Swirl gas channel, which is designed such that a swirl gas flows through it and emerges from the burner mouth in a substantially tangential direction of the burner.

The control/regulating device is preferably designed in such a way that if the determined flame length deviates from the flame length limit value or limit range, it increases or reduces the flow velocity of the axial gas in the axial gas channel and of the swirl gas in the swirl gas channel.

According to a further embodiment, the rotary kiln has an exhaust gas outlet, wherein the burner is connected to the exhaust gas outlet for conducting at least part of the exhaust gas into the burner.

According to a further embodiment, the measuring device is a camera, in particular an infrared camera.

Description of the drawings

The invention is explained in more detail below using several exemplary embodiments with reference to the accompanying figures.

Fig. 1 shows a schematic representation of a burner in a rotary kiln in a partial sectional view according to an exemplary embodiment.

Fig. 2 shows a schematic representation of a burner in a longitudinal section view according to an exemplary embodiment.

Fig. 1 shows a rotary kiln 10 with a rotary tube 12 and one inside

Rotary tube 12 arranged burner 14. The burner 14 is preferably attached to an inner wall of the rotary tube furnace 12, not shown in FIG. 1, which is the

Inner wall is a static inner wall that is not connected to the rotating tube of the

Rotary kiln rotates. For example, the burner 14 is at the end region of the

Rotary tube arranged end wall attached or extends through it.

The rotary tube 12 is preferably arranged to be rotatable about its longitudinal axis and is aligned sloping in particular in the direction of the furnace head, in particular the burner 14, so that the material to be burned is conveyed within the rotary tube due to gravity and by the rotation of the rotary tube 12 in the direction of the burner 14.

Fig. 1 further shows a schematic representation of the flame 16 of the burner 14 and the ignition gap 18. The ignition gap 18 is the distance, preferably in the axial direction of the rotary kiln 10, between the burner 14 and the flame 16. The burner 14 has a burner mouth 20, which forms the axial end of the burner 14 and from which the fuel exits the burner 14.

In particular, the ignition gap 18 is the shortest distance between the

Burner mouth 20 and the flame 16.

The rotary kiln 10 preferably has a measuring device, in particular one

Camera 22, preferably an infrared camera, which is designed and arranged to determine the ignition gap 18. The camera 22 is preferably on the inner wall of the

Rotary kiln 10, for example attached to the rotary kiln 12 or the kiln head.

It is also conceivable that the camera 22 is mounted on a static inner wall of the

Furnace head or outside the rotary kiln 10 is attached. The measuring device is preferably designed to determine the flame shape, flame length and flame width. The measuring device is preferably designed in such a way that it has a

Flame is detected when the temperature exceeds 1600 °C and/or when combustion of the fuel occurs. The measuring device preferably comprises a cooling device for cooling the measuring device.

Fig. 2 showed the burner 14 in a sectional view, with only the one in the

Rotary tube 12 extending end region of the burner 14 with the burner mouth 20 is shown.

The burner 14 includes, for example, four tubes that are arranged coaxially to one another and have different diameters. The central tube 24 with the least

Diameter is used to transport particularly lumpy fuel, such as substitute fuels from waste or used tires. The central tube 24 forms a central channel 26. Together with the fuel, a carrier gas is passed through the central tube 24, which serves for the pneumatic transport of the fuel. The carrier gas is in particular an oxygen-poor gas with a

Oxygen concentration of 0 to 35 vol%, in particular 2 to 20 vol%, preferably 10 to 15 vol%, most preferably less than 10 vol%. Preferably this has

Transport gas has a CO2 concentration of 70 to 95% by volume, in particular 80 to 90% by volume, preferably more than 75% by volume. The remaining portion of the transport gas preferably includes oxygen, nitrogen and/or water. The central tube 24 is preferably connected to a source of fuel, in particular lump substitute fuel, and a source of the transport gas.

Coaxial to the central tube 24, for example, the swirl gas tube 28 is arranged, which has a

Swirl gas channel 30 forms. The swirl gas channel 30 is preferably between the

Inner wall of the swirl gas tube 28 and the outer wall of the central tube 24 is formed and is preferably used to conduct a swirl gas. The swirl gas pipe 28 extends, for example, in the axial direction, in the direction of the burner mouth 20, over the

Central tube 24 out. The swirl gas preferably has an oxygen content of 0 to 100% by volume, in particular 30 to 75% by volume, preferably more than 90% by volume. The

Swirl gas channel 30 is preferably connected to a source for the swirl gas.

For example, the fuel pipe 32 is arranged coaxially with the swirl gas pipe 28 and forms a fuel channel 34. The fuel channel 34 is formed between the inner wall of the fuel pipe 32 and the outer wall of the swirl gas pipe 28 and is preferably used to conduct a finely lumped fuel, such as coal, as well as to conduct a carrier gas for the pneumatic transport of the fuel through the fuel channel 34. The fuel pipe 32 extends for example in axial

Direction, in the direction of the burner mouth 20, over the central tube 24 and there

Swirl gas pipe 28 out. The carrier gas preferably has an oxygen content of 0 to 30 vol%, in particular 2 to 20 vol%, preferably 10 to 15 vol%, most preferably less than 10 vol%. The transport gas preferably has a CO2 concentration of 70 to 95% by volume, in particular 80 to 90% by volume, preferably more than 75% by volume. The remaining portion of the transport gas preferably comprises

Oxygen, nitrogen and/or water. The fuel channel 34 is preferably connected to a source for the carrier gas and the particularly fine-grained fuel.

For example, the axial gas pipe 36 is arranged coaxially with the fuel pipe 32 and forms an axial gas channel 38. The axial gas channel 38 is in particular between the

The inner wall of the axial gas pipe 36 and the outer wall of the fuel pipe 32 are formed and are preferably used to conduct an axial gas. The axial gas tube 36 extends, for example, in the axial direction, in the direction of the burner mouth 20, over the

Central pipe 24, the fuel pipe 32 and the swirl gas pipe 28 out. The axial gas preferably has an oxygen content of 0 to 100% by volume, in particular 30 to 75% by volume, preferably more than 90% by volume. The axial gas channel 38 is preferably with a

Source for the axial gas connected.

The main direction of flow of the gases is marked with the arrow. The

Axial gas and the swirl gas preferably have a high pressure relative to the carrier gas

flow velocity. The direction of flow of the axial gas is in

Essentially in the axial direction of the burner, the flow direction of the

Swirl gas is directed essentially in the tangential direction of the burner. The

Swirl gas and the axial gas are preferably used to remove the gas emerging from the burner mouth 20, in particular from the fuel channel 30 and the central channel 26

Fuel to be applied with an axial and swirl impulse.

The central channel 26, the swirl gas channel 30, the fuel channel 34 and the axial gas channel 38 are each connected to a device for adjusting the flow speed and / or the amount of the respective gas, such as the carrier gas, axial gas or swirl gas. The device for adjusting the flow speed and/or the amount of gas is, for example, a valve, a fan, a nozzle and/or a diffuser.

The rotary kiln 10 has a control/regulation device which is connected to the

Camera 22 is connected to transmit the data determined by means of the camera 22, in particular the ignition distance, the flame length and / or the flame width. The

The control/regulation device is preferably connected to the device for adjusting the flow speed and/or the amount of gas and is designed in such a way that the flow speed and/or the amount of gas passes through the central channel 26, the swirl gas channel 30, the fuel channel 34 and the

Axial gas channel 38 to control/regulate flowing gases. The control/regulation device is preferably designed in such a way that it adjusts, preferably increases, reduces or leaves unchanged, the flow speed and/or the amount of gas depending on the determined ignition distance, the flame length and/or the flame width.

Preferably, the determined state variable of the burner flame is compared with a predetermined limit value or limit range and if the determined state variable deviates from the limit value or limit range

Flow rate, the amount and/or the momentum of the carrier gas and/or the fuel properties are set. It is also conceivable that the

Flow rate, the amount and/or the momentum of the carrier gas and/or the fuel properties are controlled in such a way that the “determined

State variable is a predetermined value of the flow velocity,

Quantity and/or momentum of the carrier gas and/or the fuel properties is assigned, so that the flow rate, the quantity and/or the momentum of the carrier gas and/or the fuel properties depend on the determined

State variable can be set to the respective predetermined value.

For example, the ignition gap is determined and with an ignition gap limit value or

Compare border area. If the determined ignition distance falls below the

Ignition distance limit or limit range, for example, the fuel moisture and/or the grain size of the fuel is increased. If the determined ignition distance exceeds the ignition distance limit or limit range, for example

Fuel moisture and/or the grain size of the fuel is reduced.

For example, if the ignition distance limit value is undershot or

Limit range, the CO2 content in the carrier gas increases and preferably the

Oxygen content of the carrier gas is reduced. If the determined ignition distance 18 exceeds the ignition distance limit or limit range, for example, the CO2 content in the carrier gas is reduced and preferably the oxygen content of the carrier gas is increased. For example, if the ignition distance falls below the determined ignition distance, fine-grained material, such as lime powder or

Gypsum powder is fed into the combustion zone of the rotary kiln 10 through the burner 14, in particular through the fuel channel 34 and/or the axial gas channel 38.

The burner 14 has a central channel 26 through which fuel flows together with a carrier gas. Furthermore, the burner 12 has a swirl gas channel 26 through which the swirl gas flows. The burner 12 also has an axial gas channel 38 through which the axial gas flows. In particular, the burner 12 has a

Fuel channel 34 through which fuel flows together with a carrier gas.

In particular, if the ignition gap limit value is undershot or

Limit area, the flow velocity and / or the amount of carrier gas, in particular in the central channel 26 and / or the fuel channel 34, increases.

If the determined ignition distance 18 exceeds the ignition distance limit or

The limit area is, for example, the flow speed and/or the amount of carrier gas, in particular in the central channel 26 and/or the fuel channel

34 reduced. Preferably, if the ignition distance limit value or limit range is undershot, the flow velocity of the axial gas in the

Axial gas channel 38 increases and when the ignition gap limit value is exceeded or

Limit range reduced. Preferably, if the value falls below

Ignition distance limit or limit range, the flow velocity of the

Swirl gas in the swirl gas channel 30 increases and when the

Ignition distance limit or limit range reduced.

For example, the flame length is determined and compared with a flame length limit or limit range. If the determined flame length falls below the

Flame length limit or limit range is, for example, the

Flow velocity of the axial gas in the axial gas channel 38 and of the swirl gas in the swirl gas channel 30 is reduced and increased if exceeded. The

Flow velocity of the carrier gas is not changed, for example, depending on the determined flame length. For example, in the event of a deviation

Flame length from the flame length limit or water vapor limit,

CO»2 and/or solid particles are introduced into the combustion zone. The task is carried out, for example, via the burner or via at least one additional line.

The solid particles are transported in particular through the central channel or the

Fuel channel is given up, with the water vapor and/or the CO2 preferably being given into the combustion zone through the axial gas channel 38 and/or the swirl gas channel 30. The solid particles are, for example, raw cement meal,

Limestone powder, calcined raw cement powder and/or fuel ash, these being the

Excite heat radiation within the rotary kiln and thus the expansion of the

Affect burner flame.

If the determined flame length falls below the flame length limit or

For example, the limit area is the release of water vapor, CO2 and/or the

Solid particles increased, with the task occurring if the value falls below

Flame length limit or limit range is reduced.

For example, the flame shape is determined and compared with a large number of predetermined flame shapes. Preferably, each flame shape is assigned a respective predetermined value of the flow velocity, quantity and/or momentum of the carrier gas and/or the fuel properties, so that the

Flow rate, the amount and/or the momentum of the carrier gas and/or the fuel properties can be set to the respective predetermined value depending on the determined flame shape. The flame shape is, for example, the two-dimensional or three-dimensional extent of the

Burner flame inside the rotary kiln.

List of reference symbols 10 Rotary kiln 12 Rotary tube 14 Burner 16 Burner flame 18 Ignition section 20 Burner mouth 22 Measuring device / camera 24 Central tube 26 Central channel 28 Swirl gas pipe 30 Swirl gas channel 32 Fuel pipe 34 Fuel channel 36 — Axial gas pipe 38 Axial gas channel

Claims (18)

Patent claims 1. Method for operating a burner (14) of a rotary kiln (10), wherein the gas streams supplied to the rotary kiln (10) comprise in total more than 50% by volume of oxygen, the burner (14) having a burner mouth (20) from which a fuel-gas mixture is discharged and at least one state variable of the burner flame (16), in particular the ignition gap (18), the flame shape, the flame length and/or the flame width, is determined, characterized in that the flow velocity, the quantity and/or the impulse of the fuel-gas mixture and/or the fuel properties are controlled/regulated depending on the determined state variable. 2. The method according to claim 1, wherein the state variable of the burner flame (16) is compared with a limit value or limit range and, if the determined state variable deviates from the limit value or limit range, the flow velocity, the quantity and / or the momentum of the fuel-gas mixture and / or the fuel properties are adjusted. 3. The method according to any one of the preceding claims, wherein the ignition gap (18) is determined and compared with an ignition gap limit value or limit range and where if the determined ignition gap (18) deviates from the ignition distance limit value or limit range, the fuel moisture, the grain size of the fuel, the CO2 content of the fuel-gas mixture and/or the oxygen content of the fuel-gas mixture is increased or reduced. 4. The method according to any one of the preceding claims, wherein the burner (14) has an axial gas channel (38), through which an axial gas flows and emerges from the burner mouth (20) in a substantially axial direction of the burner (14), and a swirl gas channel (30 ) through which a swirl gas flows and emerges from the burner mouth (20) in a substantially tangential direction of the burner (14) and wherein the ignition gap (18) is determined and compared with an ignition gap limit or limit range and in the event of a deviation in the determined ignition gap (18) the flow velocity, the oxygen content and/or the CO2 content of the axial gas and/or the swirl gas is increased or reduced by the ignition distance limit value or limit range. 5. The method according to any one of the preceding claims, wherein the flame length is determined and compared with a flame length limit or limit range and wherein if the determined flame length deviates from the flame length limit or limit range, the flow velocity and / or the momentum of the fuel-gas mixture is increased or reduced. 6. The method according to any one of the preceding claims, wherein the flame length is determined and compared with a flame length limit or limit range and wherein if the determined flame length deviates from the flame length limit or limit range, water vapor, CO2, and / or solid particles are introduced into the combustion zone. 7. The method according to claim 5, wherein the burner (14) has an axial gas channel (38), through which an axial gas flows and emerges from the burner mouth (20) in a substantially axial direction of the burner (14), and a swirl gas channel (30). , through which a swirl gas flows and emerges from the burner mouth (20) in a substantially tangential direction of the burner (14) and where if the determined flame length deviates from the flame length limit or limit range, the flow velocity of the axial gas in the axial gas channel and of the swirl gas in the swirl gas channel is increased or decreased. 8. The method according to any one of the preceding claims, wherein the exhaust gas from the rotary kiln (10) is at least partially fed to the burner (14). 9. Method according to one of the preceding claims, wherein the state variable of the burner flame (16) is determined using a camera (22), in particular an infrared camera. 10. Rotary kiln (10) for burning raw meal into cement clinker, having a combustion zone formed within the rotary kiln (10), a burner (14) with a burner mouth (20) for releasing a fuel-gas mixture into the combustion zone, a measuring device (22), which is designed and arranged in such a way that it determines at least one state variable of the burner flame (16), in particular the ignition gap (18), the flame length and/or the flame width, characterized in that the rotary kiln (10) has a control/regulation device , which is designed in such a way that it controls/regulates the flow velocity, the quantity and/or the momentum of the fuel-gas mixture and/or the fuel properties depending on the determined state variable. 11.Rotary kiln according to claim 10, wherein the control/regulation device is designed such that it compares the state variable of the burner flame (16) with a limit value or limit range and, if the determined state variable deviates from the limit value or limit range, the flow speed, the quantity and / or adjusts the impulse of the fuel-gas mixture and/or the fuel properties. 12.Rotary kiln according to claim 10 or 11, wherein the measuring device (22) is designed such that it determines the ignition gap (18) and the control/regulation device is designed such that it compares the determined ignition gap (18) with an ignition gap limit value or limit range compares and whereby if the determined ignition distance (18) deviates from the ignition distance limit or limit range, the fuel moisture, the grain size of the fuel, the CO2 content of the fuel-gas mixture and/or the oxygen content of the fuel-gas mixture increases or decreases. 13. Rotary kiln according to one of claims 10 to 12, wherein the burner (14) has an axial gas channel (38) which is designed such that an axial gas flows through it and in the essentially axial direction of the burner (14) from the burner mouth ( 20), and wherein the burner (14) has a swirl gas channel (30) which is designed such that a swirl gas flows through it and emerges from the burner mouth (20) in a substantially tangential direction of the burner (14) and the measuring device (22) is designed in such a way that it determines the ignition gap (18) and the control/regulation device is designed in such a way that if the determined ignition gap (18) deviates from a predetermined ignition gap limit or limit range, the flow speed, the oxygen content and / or the CO2 content of the axial gas and/or the swirl gas increases or decreases. 14. Rotary kiln according to one of claims 10 to 13, wherein the measuring device (22) is designed such that it determines the flame length and the control/regulation device is designed such that it compares the determined flame length with a flame length limit or limit range and at a Deviation of the determined flame length from the flame length limit or limit range increases or decreases the flow velocity and/or the momentum of the fuel-gas mixture. 15.Rotary kiln according to one of claims 10 to 14, wherein the rotary kiln (10) has a line for feeding water vapor, CO2, and / or solid particles into the combustion zone and wherein the measuring device (22) is designed such that it determines the flame length and the control/regulation device is designed in such a way that it compares the determined flame length with a flame length limit value or limit range and, if the determined flame length deviates from the flame length limit value or limit range, water vapor, CO2, and/or solid particles are introduced into the combustion zone. 16.Rotary kiln according to claim 14, wherein the burner has an axial gas channel (38) which is designed such that an axial gas flows through it and emerges from the burner mouth (20) in a substantially axial direction of the burner (14), and wherein the Burner (14) has a swirl gas channel (30), which is designed such that a swirl gas flows through it and emerges from the burner mouth (20) in a substantially tangential direction of the burner (14), and wherein the control/regulation device is designed in this way that if the determined flame length deviates from the flame length limit or limit range, it increases or reduces the flow velocity of the axial gas in the axial gas channel (38) and of the swirl gas in the swirl gas channel (30). 17.Rotary kiln according to one of claims 10 to 16, wherein the rotary kiln (10) has an exhaust gas outlet and the burner (14) is connected to the exhaust gas outlet for conducting at least part of the exhaust gas into the burner (14). 18.Rotary kiln according to one of claims 10 to 17, wherein the measuring device (22) is a camera, in particular an infrared camera.