Apparatus for heat treatment of free-floating raw material and method for operating such apparatus

Abstract

The invention relates to a device (14) for thermally treating free-floating raw materials, in particular cement raw meal and / or mineral products, having a riser line (62) through which hot gases can flow, wherein the riser line has at least one fuel inlet (48, 50) for introducing fuel into the riser line (62), wherein the riser line (62) has at least one raw meal inlet (44, 46) for introducing raw meal into the riser line (62), the raw meal inlet being arranged upstream of the fuel inlet (24) in the flow direction of the gases within the riser line (62). The invention also relates to a method for thermally treating free-floating raw materials, in particular cement raw meal and / or mineral products, having the following steps: - introducing fuel via a fuel inlet (48, 50) into a riser line (62) for conducting hot gases, and - introducing raw meal into the riser line (62), wherein the raw meal is introduced into the riser line (62) upstream of the fuel inlet (48, 50) in the flow direction of the gases.

Description

Technical Field

[0001] This invention relates to an apparatus for heat treatment of free-floating raw materials, particularly cement raw materials and / or mineral products. Background Technology

[0002] It is known from existing technology to use calcining furnaces to heat-treat raw materials, particularly in cement production facilities.

[0003] Furthermore, it is known to introduce oxygen-containing gas into rotary kilns or calciners in cement production facilities to burn carbonaceous fuels. To reduce the amount of exhaust gas and eliminate the need for complex purification methods, for example, it is known from DE 10 2018 206 673A1 to use combustion gases that are as oxygen-rich as possible, resulting in high CO2 content in the exhaust gas. DE 10 2018 206 673A1 discloses introducing oxygen-rich gas into a cooler inlet region to preheat the gas and cool the clinker.

[0004] If an oxygen-rich combustion gas with an oxygen fraction of at least 30% to 100% is used, very high temperatures may occur in the calcining furnace and the furnace itself. If these high temperatures occur over a long period or permanently in the region of the calcining furnace near the wall, this can potentially lead to damage to the furnace's inner wall. If the hot zone occurs in conjunction with the introduced hot material, the molten phase of the hot material to be calcined is also expected.

[0005] Therefore, the object of the present invention is to provide an apparatus for heat treatment of free-floating materials, wherein the safe operation of the apparatus is ensured while simultaneously obtaining exhaust gas with a high CO2 content. Summary of the Invention

[0006] According to the present invention, this objective is achieved by the apparatus and method of the present invention.

[0007] According to a first aspect, an apparatus for heat-treating freely floating raw materials, particularly carbonate-containing materials, preferably cement raw materials and / or mineral products, includes a riser through which hot gas can flow, wherein the riser has at least one fuel inlet for introducing fuel into the riser. The riser also has at least one raw material inlet for introducing raw material into the riser, the raw material inlet being arranged upstream of the fuel inlet in the direction of gas flow within the riser.

[0008] Equipment for heat-treating free-floating raw materials is, for example, a calcining furnace for calcining, particularly preheating, raw materials, such as in decarburization equipment used for producing cement or materials containing annealing losses. Equipment for heat-treating free-floating raw materials is, for example, arranged in equipment used for producing calcined limestone or dolomite, for preparing recalcined residues or FGD gypsum. Raw materials are, for example, limestone or a mixture of lime mud and clay, supplemented as needed with iron ore, sand, or other materials, or carbonate-containing materials such as limestone, dolomite, or mixtures containing them. Fuels are, for example, carbon, petroleum coke, natural gas, treated residential and industrial waste, sewage sludge, biomass, or liquid solvents.

[0009] The riser line preferably comprises a vertically extending conduit through which hot gas can flow, particularly from bottom to top. The riser line preferably has a hot gas inlet for introducing hot gas with an oxygen fraction of 20% to 100%, preferably 30% to 80%. The lower end of the riser line preferably forms a hot gas inlet for introducing hot gas into the riser line. The riser line optionally has a combustion gas inlet, arranged separately from the hot gas inlet, for introducing combustion gas with an oxygen fraction of 20% to 100% by volume, particularly 30% to 80% by volume. The hot gas is preferably exhaust gas from a combustion facility, such as a furnace in a cement production facility. The hot gas preferably has an oxygen concentration of 20% to 100% by volume, particularly 30% to 80% by volume. The riser line has, for example, multiple fuel inlets for introducing fuel into the riser line. Each fuel inlet particularly includes at least one or more fuel lines, which preferably extend radially through the walls of the riser line. The riser line preferably has multiple raw material inlets, wherein at least one raw material inlet is located upstream of all fuel inlets. The riser line preferably has two raw material inlets arranged continuously along the gas flow direction. At least one fuel inlet is preferably located between the two raw material inlets.

[0010] The distribution of raw materials upstream of the fuel inlet prevents overheating within the riser line, and thus, for example, prevents damage to the inner walls of the riser line. The combustion zone generated by fuel combustion can directly dissipate heat to the raw material particles.

[0011] Compared to conventional devices using air as an oxidant, the solid-to-gas ratio in the preferred calcining furnace is advantageously significantly higher. The local solid load is greater than 1.5 kg / kg gas, for example, particularly from 1.5 kg / kg gas to 8 kg / kg gas. It is preferable to achieve the maximum portion of the fuel's heat in the device, greater than 60%, for example, about 80%. Due to the introduction of raw material upstream of the fuel inlet, sufficient radiators are provided to prevent overheating, despite the initial oxygen concentration being 40-80% (which initiates vigorous combustion). If coarse alternative fuels are to be burned, for example, with an edge length greater than 100 mm, a sloping zone with a longer fuel residence time is preferably provided. Examples of such sloping zones are steps, pushers, reciprocating grids, or other mechanical or pneumatic devices. These devices function, for example, as combustion chambers, pre-combustion chambers, or solely for drying and preheating or partial gasification of the introduced fuel. The fuels can be of any type regarding their particle size distribution and their calorific value.

[0012] The calcination reaction is optionally carried out under a CO2 partial pressure, which is 10%-60% at the start of the calcination furnace and as high as 95% at the end of the calcination furnace. Therefore, the calcination reaction is preferably carried out at a temperature higher than that of conventional equipment, which is 700 to 1100°C, preferably 900 to 1000°C.

[0013] According to a first embodiment, the riser line has at least one inert gas inlet for introducing inert gas into the riser line. For example, the riser line has multiple, particularly two or three, inert gas inlets arranged continuously along the gas flow direction in the riser line. For example, the fuel inlet and the inert gas inlet are arranged separately from each other and each forms an inlet into the riser line. The fuel inlet and the inert gas inlet preferably form an inlet in the riser line together. The fuel and the inert gas are preferably supplied to the riser line separately in a common pipeline. This is structurally less complex and therefore more cost-effective. The inert gas preferably also serves as a temperature absorber and also prevents the introduced fuel from spontaneously combusting directly at the fuel inlet, particularly at the burner orifice or burner nozzle orifice.

[0014] Inert gases, such as CO2 or water vapor, are used. Supplying an inert gas to the equipment provides the advantage of delayed combustion, particularly slowing down combustion, thereby preventing damage to the equipment.

[0015] The riser line has, for example, multiple inert gas inlets, particularly for introducing different inert gases. It is also conceivable that the riser line has multiple fuel distribution devices, particularly two or three, each associated with an inert gas inlet. The fuel distribution devices are preferably arranged at intervals between each other along the length and / or width of the riser line. For example, the fuel distribution devices are offset from each other at angles from 0° (preferably 60°) to 270° across the cross-section of the calciner riser line. Different types of fuel distribution devices can be combined with each other and can also be arranged differently here.

[0016] According to another embodiment, the riser pipeline has at least two processing zones arranged continuously in the gas flow direction, the at least two processing zones optionally having different diameters from each other, and wherein the pre-processing zone in the gas flow direction has a raw material inlet for introducing raw material into the pre-processing zone. The pre-processing zone preferably has a smaller diameter than the processing zone arranged downstream.

[0017] The processing zone is, for example, a section of a riser pipe with at least one inlet for introducing raw materials, fuel, and / or inert gas. The pre-treatment zone preferably directly adjoins a cross-sectional contraction along the gas flow direction, the diameter of which is relatively small and preferably constant relative to the processing zone. Each processing zone has, for example, an intermediate zone with a constant diameter and respective zones arranged before and after it with varying, decreasing, or increasing diameters. In the gas flow direction, the processing zone preferably has an extension zone whose cross-section increases in the flow direction. A zone with a constant cross-section adjoins the extension zone. Preferably, another zone with a decreasing or expanding cross-section adjoins the zone with a constant cross-section. The extension zone with an increasing cross-section preferably has an opening angle of 10° to 60°, preferably 12° to 30°. In particular, the front section of the processing zone in the flow direction directly adjoins the cross-sectional contraction of the riser pipe with its expanding cross-section. The riser pipe preferably has more than two, particularly three or four, consecutively arranged processing zones.

[0018] According to another embodiment, the riser line has at least one cross-sectional contraction between the processing zones, which has a diameter smaller than that of the processing zone. The cross-sectional contraction is preferably a section of the riser with a constant diameter smaller than the sections of the riser arranged directly before and after the cross-sectional contraction in the flow direction. For example, the cross-sectional contraction is arranged between two adjacent processing zones. Such cross-sectional contraction ensures localized acceleration of the flow, wherein this localized acceleration is slowed down in the adjacent region with a larger diameter in the flow direction. This ensures complete mixing of the gas and the raw material.

[0019] According to another embodiment, the fuel inlet is located downstream of the pretreatment area.

[0020] For example, the equipment has two or more fuel inlets, all of which are located downstream of the pretreatment area. Only one or more inlets for introducing raw materials into the riser line are preferably located in the pretreatment area.

[0021] According to another embodiment, the riser line has another cross-sectional contraction upstream of the pretreatment zone. The pretreatment zone is preferably arranged between the two cross-sectional contractions. Preferably, at least a portion of the raw material is distributed into the pretreatment zone, where the cross-sectional contraction causes a decrease in flow velocity within the treatment zone, and thus the raw material mixes more thoroughly with the hot gas. This avoids localized areas with extremely high temperatures, thereby preventing damage to the riser wall.

[0022] According to another embodiment, the riser has at least two raw material inlets for introducing raw material into the riser, wherein each raw material inlet is arranged in a different processing zone of the riser. Specifically, the raw material inlets are located at different height levels, preferably continuously arranged in the flow direction of the riser. Preferably, each processing zone has at least one raw material inlet. This allows for the gradual distribution of raw material into the riser, such that the raw material is introduced into different zones of the riser and optimally mixed with the hot gas in each zone.

[0023] According to another embodiment, at least one of the fuel inlets has at least one or more fuel lines extending in the radial direction of the riser line, the fuel lines extending through the riser line wall into the riser line, and wherein at least one of the raw material inlets has at least one or more raw material lines extending in the radial direction of the riser line, the raw material lines extending through the riser line wall into the riser line. According to another embodiment, the fuel lines extend into the riser line at an angle of 0° to 50°, particularly 20° to 30°, relative to the raw material lines.

[0024] According to another embodiment, at least one temperature measuring unit is arranged in the riser line to determine the temperature within the riser line. The device includes a regulating unit connected to the temperature measuring unit to transmit the determined temperature, and the regulating unit is designed to regulate the amount of raw material, inert gas, and / or fuel entering the riser line according to the determined temperature. Preferably, the raw material inlet, fuel inlet, and / or inert gas inlet each have a metering element, such as a baffle or valve, for setting the amount of raw material, inert gas, or fuel to be introduced into the riser line. Each metering element is preferably connected to the regulating unit to set the amount of raw material, inert gas, or fuel to be introduced into the riser line.

[0025] The temperature measuring unit preferably includes a thermocouple or acoustic gas temperature measurement. The temperature measuring unit is specifically attached to the inner wall of the riser line and is preferably designed to determine the gas temperature within the riser line. For example, the riser line has two temperature measuring units arranged continuously along the flow direction. Specifically, each temperature measuring unit is associated with a fuel inlet and arranged downstream, preferably directly at or adjacent to the fuel inlet. The temperature measuring unit is specifically designed and arranged to determine the temperature at or near the fuel inlet.

[0026] The regulating unit is preferably designed in such a way that it compares a determined temperature with a predetermined temperature limit or temperature range, and increases or decreases the amount of fuel, raw material, and / or inert gas in the riser line if the determined temperature deviates from the temperature limit or temperature range. For example, if the temperature determined by the temperature measuring unit exceeds the temperature limit or temperature range, the amount of fuel is reduced, particularly the amount of fuel flowing into the riser line through the fuel inlet associated with the corresponding temperature measuring unit. Conversely, if the temperature determined by the temperature measuring unit is below the temperature limit or temperature range, the amount of fuel flowing into the riser line through the fuel inlet associated with the corresponding temperature measuring unit is increased.

[0027] Specifically, the regulating unit is designed such that if the determined temperature deviates from the temperature limit or temperature range, the regulating unit reduces or increases the amount of inert gas in the riser line. For example, if the determined temperature exceeds the temperature limit or temperature range, the amount of inert gas flowing into the riser line through the inert gas inlet associated with the corresponding temperature measuring unit is preferably reduced. For example, if the determined temperature is below the temperature limit or temperature range, the amount of inert gas flowing into the riser line through the inert gas inlet associated with the corresponding temperature measuring unit is preferably increased. The inert gas inlet or fuel inlet associated with the corresponding temperature measuring unit is preferably the inert gas inlet and fuel inlet closest to the corresponding temperature measuring unit.

[0028] For example, if the temperature determined by the temperature measuring unit exceeds the temperature limit or temperature limit range, the amount of raw material flowing into the riser through at least one raw material inlet is increased. The total amount of raw material flowing into the riser is preferably kept constant, such that the amount of raw material decreases at one raw material inlet and increases accordingly at at least one other raw material inlet. If, for example, the temperature determined by the temperature measuring unit is below the temperature limit or temperature limit range, the amount of raw material flowing through at least one raw material inlet is reduced.

[0029] Inside the riser line of the equipment, for example, at least one guiding element is provided for guiding the gas flow. Therefore, it is preferable to achieve better and more complete mixing of the gas and raw material. This function is particularly important for process control using high oxygen and low nitrogen content, because the reduced gas volume in the equipment due to the lack of nitrogen fraction results in a higher load after material introduction compared to equipment operating using air as an oxidant. Therefore, for particle carrying capacity, it is advantageous if the material is uniformly distributed across the cross-section of the riser line of the calcining furnace. This prevents raw material from settling into areas located downstream in the lower riser line. The guiding element is designed, for example, as a plate, box, cone, and / or pyramid. Multiple guiding elements are preferably arranged within the riser line, for example, these guiding elements are evenly spaced from each other. The guiding elements are, for example, formed of ceramic or ceramic fiber composite material. The guiding elements are particularly arranged inside the riser line and / or in the fuel inlet. Preferably, a guiding element is provided at the outlet of the fuel outlet in the riser, thereby guiding the fuel into the riser line through the guiding element. The guiding element preferably extends from the fuel inlet into the riser line. The guiding element is designed and arranged in such a way that it guides the fuel at an angle relative to the inner wall of the riser. For example, the guiding element forms a diffuser with a cross-section that expands relative to the fuel inlet.

[0030] For example, the device has multiple fuel distribution units, each including a fuel inlet and an inert gas inlet, with a guide element associated with each fuel distribution unit. The corresponding fuel distribution units are arranged, for example, at the same height level as the guide element, or directly connected upstream or downstream of the guide element. This allows for optimized distribution of raw materials and inert gas within the riser line, particularly in the area of ​​the fuel distribution units.

[0031] The aforementioned facilities are, for example, arranged in a cement plant. This cement production equipment preferably includes:

[0032] - A preheater for preheating raw materials.

[0033] - A calcining furnace for calcining preheated raw materials, wherein the calcining furnace is the equipment described above.

[0034] - A furnace having a furnace burner, such as a burner lance for burning calcined hot materials to form cement clinker, wherein the furnace has a combustion gas inlet for introducing combustion gases having an oxygen fraction of 30% to 100% into the furnace, and

[0035] - A cooler used to cool cement clinker.

[0036] -The calcining furnace and the furnace each have at least one fuel inlet for introducing fuel into the calcining furnace and the furnace.

[0037] The calcining furnace and / or furnace each have at least one inert gas inlet for introducing inert gas into the calcining furnace and furnace, respectively. The calcining furnace is particularly the aforementioned equipment for performing heat treatment.

[0038] The preheater of the cement production facility preferably comprises multiple cyclone stages, each cyclone stage having at least one cyclone separator for separating solids from the gas stream. Between the last cyclone stage and the next cyclone stage, a calcining furnace is arranged, having a riser line in which the raw material is heated by a calcining furnace ignition system, which may include one or more combustion points.

[0039] Raw materials preheated in a preheater and calcined in a calcining furnace are then supplied to the furnace. The furnace is preferably a rotary kiln with a rotating tube capable of rotating about its longitudinal axis, the rotating tube preferably being slightly inclined in the direction of material transport, so that the material moves in the transport direction due to the rotation of the rotating tube and gravity. The furnace preferably has a material inlet at one end for introducing the preheated calcined raw materials, and a material outlet at the end opposite the material inlet for discharging the calcined clinker into a cooler. A furnace head is preferably located at the material outlet side end of the furnace, having a furnace burner for burning the material and preferably at least one fuel inlet for introducing fuel into the furnace, preferably via the furnace burner and / or via a fuel lance. The furnace preferably has a sintering zone in which the material is at least partially melted, and the sintering zone particularly has a temperature of 1500°C to 1900°C, preferably 1450°C to 1750°C. The sintering zone includes, for example, a furnace head, preferably located in the rear third of the furnace in the direction of material transport.

[0040] Oxidizing combustion gases are introduced directly into the furnace head, either entirely or partially, for example, where the furnace head has a combustion gas inlet. The combustion gases are preferably introduced into the furnace entirely or partially via the furnace's material outlet. The combustion gases supplied to the furnace have an oxygen fraction, for example, greater than 30% to 75%, preferably greater than 95%. The combustion gases are, for example, composed entirely of pure oxygen, where in this case the oxygen fraction is 100%. The furnace burner can be, for example, a burner lance. A cooler for cooling the cement clinker is preferably adjacent to the furnace's material outlet.

[0041] The cooler has a conveying unit for conveying loose material through a cooling gas chamber in the conveying direction. The cooling gas chamber includes a first cooling gas chamber section having a first cooling gas flow and a second cooling gas chamber section adjacent thereto in the conveying direction of the loose material having a second cooling gas flow. The cooling gas chamber is preferably defined at the top by a cooling gas chamber cover, at the bottom by dynamic and / or static grids, and preferably by the loose material placed thereon. The cooling gas chamber is, in particular, the entire chamber of the cooler above the loose material through which the cooling gas flows. The cooling gas flow passes through the dynamic and / or static grids, in particular through the conveying unit, through the loose material, and into the cooling gas chamber. The first cooling gas chamber section is preferably arranged directly after the cooler inlet, in particular the material outlet of the furnace, in the flow direction of the loose material to be cooled. Clinker preferably falls from the furnace into the first cooling gas chamber section.

[0042] Preferably, only the first cooling gas flow enters the first cooling gas chamber section, which is accelerated, for example, by a fan, a pressurized container, or another corresponding device. A second cooling gas chamber section is adjacent to the first cooling gas chamber section in the direction of loose material transport and is preferably separated from the first cooling gas chamber section relative to the gas technology by a separation device. Preferably, the second cooling gas flow, accelerated, for example, by at least one fan, flows exclusively in the second cooling gas chamber section.

[0043] The first cooling gas flow passing through the first cooling gas chamber section is, for example, pure oxygen or a gas having a nitrogen and / or argon and / or oxygen fraction greater than 20.5%, particularly greater than 30% to 75%, preferably greater than 95%, with a volume percentage of less than 35%, particularly less than 21%, preferably 15% or less. The first cooling gas chamber section is preferably directly adjacent to the furnace material outlet, preferably at the furnace head, such that the cooling gas is heated in a cooler and subsequently flows into the rotary kiln and is then used as combustion gas. The second cooling gas flow is, for example, air.

[0044] The present invention also includes a method for heat-treating free-floating raw materials, particularly cement raw meal and / or mineral products, the method comprising the following steps:

[0045] - Fuel is introduced into the riser line via the fuel inlet to conduct hot gas, and

[0046] - Raw material is introduced into the riser line, wherein the raw material is introduced into the riser line upstream of the fuel inlet along the direction of gas flow.

[0047] According to this method, the advantages and embodiments described with reference to the equipment are also applicable to the method for heat treatment of raw materials.

[0048] The hot gas is preferably introduced into the riser line via a hot gas inlet, particularly from below, wherein the hot gas has an oxygen concentration of 20% to 100% by volume, particularly 30% to 90% by volume. Optionally, the combustion gas is introduced into the riser line separately from the hot gas, wherein the combustion gas has an oxygen fraction of 20% to 100% by volume, particularly 30% to 90% by volume. For example, within the riser line, a CO2 partial pressure of 10% to 60% is set at the beginning of the riser line, and up to 95% is set at the end of the riser line. Preferably, a temperature of 700 to 1100°C, more preferably 900 to 1000°C, is set inside the apparatus.

[0049] According to one implementation scheme, inert gas is introduced into the riser line. Preferably, the inert gas is introduced into the riser line downstream of the raw material inlet.

[0050] According to another embodiment, the riser has at least two processing zones arranged continuously in the gas flow direction, the at least two processing zones preferably having different diameters from each other, and wherein raw material is introduced into the pretreatment zone in the gas flow direction.

[0051] According to another embodiment, the temperature is determined by at least one temperature measuring unit within the riser pipeline, and wherein the amount of raw material, inert gas, and / or fuel in the riser pipeline is adjusted according to the determined temperature.

[0052] According to another embodiment, fuel is introduced into the riser line via at least two fuel inlets arranged continuously in the direction of gas flow, wherein more fuel is introduced at the first fuel inlet than at the other fuel inlet in the direction of flow. The amount of fuel at the first fuel inlet in the direction of flow is preferably about 20% to 120%, particularly 50% to 100%, of the total fuel supplied to the riser line.

[0053] According to another implementation, approximately 20% to 60% of the total amount of raw material introduced into the riser pipeline is introduced into the pretreatment area. Attached Figure Description

[0054] The invention will now be explained in more detail with reference to the accompanying drawings and several exemplary embodiments.

[0055] Figure 1 A schematic diagram of an apparatus for heat-treating raw materials according to an exemplary embodiment is shown.

[0056] Figure 2 It shows that it has the following characteristics: Figure 1 A schematic diagram of a cement production facility, or 3, for equipment used in heat treatment.

[0057] Figure 3A schematic diagram of an apparatus for heat treatment of raw materials is shown according to another exemplary embodiment.

[0058] Figure 4 The following is illustrated according to another exemplary embodiment: Figure 3 A schematic diagram showing the details of the equipment used for heat treatment. Detailed Implementation

[0059] Figure 1 An apparatus 14 is shown for heat treatment of free-floating raw materials, particularly cement raw meal and / or mineral products. This apparatus 14 is particularly a calcining furnace, used, for example, in cement production facilities, for calcining preheated raw meal. The raw meal is preferably cement raw meal, mineral materials such as limestone, ore, or clay. The raw meal is preferably limestone or a mixture of limestone slurry and clay, and if desired, may be supplemented with iron ore, sand, or other materials, or carbonate-containing materials such as limestone, dolomite, or mixtures thereof.

[0060] The device 14 includes a riser line 62 through which hot gas preferably flows from bottom to top. The riser line 62 extends vertically, for example, and has an inlet, particularly in its lower region, for introducing hot gas, such as exhaust gas from a combustion unit, for example, a rotary kiln in a cement production facility. The flow direction of the hot gas within the riser line 62 is indicated by arrows at its bottom and top ends.

[0061] The riser line 62 has multiple different diameters. For example, the riser line 62 has two treatment zones 32, 33 arranged continuously along the gas flow direction. A first pretreatment zone 32 is arranged in the flow direction in front of the second treatment zone 33, wherein the diameter of the first treatment zone 32 is, for example, smaller than the diameter of the second treatment zone 33. For example, a section of the riser line 62 with a diameter larger than that of the second treatment zone 33 is adjacent to the second treatment zone 33. Each treatment zone has, for example, a substantially constant diameter. Between the two treatment zones 32, 33, the riser line 62 has a cross-sectional contraction 40, particularly a region with a smaller diameter than the adjacent treatment zones 32, 33. For example, each treatment zone 32, 33 has a section with a substantially constant diameter and an adjacent section with a varying diameter (e.g., decreasing or increasing). Upstream of the first treatment zone 32, the riser line 62 has another cross-sectional contraction 42, on which the first treatment zone 32 of the riser line 62 is preferably directly adjacent. The diameter of the cross-sectional contraction 42 corresponds, for example, to the diameter of the cross-sectional contraction 40 arranged between the two processing zones 32, 33. Each processing zone 32, 33 has at least one inlet for introducing raw materials, fuel or inert gas.

[0062] At the lower end of the riser line 62, for example at the cross-sectional contraction 42, adjacent to the furnace inlet of a rotary kiln in a cement production facility, furnace exhaust gas is directed to the riser line through the furnace inlet. It is also conceivable that the lower end of the riser line 62 is connected to the exhaust pipe of equipment used for burning lime.

[0063] Facility 14 has a first raw material inlet 44 connected to a first processing area 32 of the lift line 62. The raw material inlet 44 preferably has at least one or more raw material lines extending radially in the lift line and arranged circumferentially around the lift line, for example, at a horizontal height. The raw material lines preferably each extend through the wall of the lift line 62 into the first processing area 32. The first raw material inlet 44 is, for example, centrally located in the first processing area 32 in a vertical direction. Facility 14 has a second raw material inlet 46, which is designed similarly to the first raw material inlet 44 and is preferably centrally located in the second processing area 33.

[0064] The device 14, for example, has two fuel inlets 48 and 50, both arranged in a second processing zone 33. Each fuel inlet 48 and 50 has, for example, at least one or more fuel lines extending radially in the lift line 62 and arranged circumferentially around the lift line 62, for example, at a certain height level. The fuel lines preferably extend through the wall of the lift line 62 into the second processing zone 33. The fuel inlets 48 and 50 are continuously arranged in the second processing zone 33 at different height levels of the lift line 62 along the gas flow direction. For example, the first fuel inlet 48 is arranged in the lower region of the second processing zone 33, particularly in the inlet region, and the second fuel inlet 50 is arranged in the upper region of the second processing zone 33, particularly in the outlet region. The first fuel inlet 48 is, for example, arranged upstream of the second raw material inlet 46, and the second fuel inlet 50 is, for example, arranged downstream of the second raw material inlet 46.

[0065] The device 14 has, for example, two inert gas inlets 52 and 54, each leading to a second processing area 32. The first inert gas inlet 52 is, for example, located upstream of the second raw material inlet 46, and the second inert gas inlet 54 is, for example, located downstream of the second raw material inlet 46.

[0066] The device 14 also has two temperature measuring units 56 and 58, both attached to the second processing area 33. For example, the temperature measuring units 56 and 58 are associated with a fuel inlet 48 and 50, respectively, and are arranged downstream, preferably directly at or adjacent to the fuel inlet 48 and 50. The first temperature measuring unit 56 is associated with the first fuel inlet 48, for example, and the second temperature measuring unit 58 is associated with the second fuel inlet 50.

[0067] The device 14 also includes a regulating unit 60, which is connected to a temperature measuring unit 58 to transmit the determined temperature. The regulating unit 60 is preferably connected to a first raw material inlet 44 and a second raw material inlet 46 to regulate the amount of raw material flowing into the riser line 62 through the respective raw material inlets 44, 46. The regulating unit 60 is optionally connected to fuel inlets 48, 50 and / or inert gas inlets 52, 54 to regulate the amount of fuel and / or inert gas flowing into the riser line 62 through the respective fuel inlets 48, 50 and / or inert gas inlets 52, 54. The raw material inlets 46, 48, fuel inlets 48, 50 and / or inert gas inlets 52, 52 have, for example, metering units, such as valve flaps or valves, through which the corresponding amounts of raw material, fuel and inert gas can be regulated. The metering units are preferably connected to the regulating unit.

[0068] The regulating unit 60 preferably compares the determined temperature with a predetermined temperature limit or temperature limit range. Specifically, the regulating unit 60 is designed such that if the determined temperature deviates from the temperature limit or temperature limit range, the regulating unit 60 reduces or increases the amount of fuel in the booster line 62. If, for example, the temperature measured by one of the temperature measuring units 56, 58 exceeds the temperature limit or temperature limit range, the amount of fuel flowing into the second processing zone 33 through the fuel inlets 48, 50 associated with the corresponding temperature measuring units 56, 58 is reduced. If, for example, the temperature determined by one of the temperature measuring units 56, 58 is below the temperature limit or temperature limit range, the amount of fuel flowing into the second processing zone 33 through the fuel inlets 48, 50 associated with the corresponding temperature measuring units 56, 58 is increased.

[0069] Specifically, the regulating unit 60 is designed to reduce or increase the amount of inert gas in the riser line 62 if the determined temperature deviates from the temperature limit or temperature limit range. If, for example, the temperature determined by one of the temperature measuring units 56, 58 exceeds the temperature limit or temperature limit range, the amount of inert gas flowing into the second processing zone 33 through the inert gas inlets 52, 54 associated with the corresponding temperature measuring units 56, 58 is reduced. For example, if the temperature determined by one of the temperature measuring units 56, 58 is below the temperature limit or temperature limit range, the amount of inert gas flowing into the second processing zone 33 through the inert gas inlets 52, 54 associated with the corresponding temperature measuring units 56, 58 is increased. The inert gas inlets 52, 54 or fuel inlets 48, 50 associated with the corresponding temperature measuring units 56, 58 are preferably inert gas inlets 52, 64 and fuel inlets 48, 50 closest to the corresponding temperature measuring units 56, 58.

[0070] Specifically, the regulating unit 60 is designed such that if the determined temperature deviates from the temperature limit or temperature limit range, the regulating unit 60 reduces or increases the amount of raw material in the lift line 62. If, for example, the temperature determined by one of the temperature measuring units 56, 58 exceeds the temperature limit or temperature limit range, the amount of raw material flowing through at least one of the raw material inlets 44, 46 is increased. Preferably, the total amount of raw material flowing in the lift line 62 remains constant, such that the amount of raw material decreases at one raw material inlet 44 and increases accordingly at at least one other raw material inlet 46. For example, if the temperature determined by one of the temperature measuring units 56, 58 is below the temperature limit or temperature limit range, the amount of raw material flowing through at least one of the raw material inlets 44, 46 is reduced. For example, if the limit or limit range is not reached, the amount of raw material flowing into the second processing zone 33 through the second raw material inlet 46 is reduced, and the amount of raw material through the first raw material inlet 44 is increased accordingly.

[0071] Figure 2 A cement production facility 10 is shown, comprising a single-stream preheater 12 for preheating raw meal, a calciner 14 for calcining raw meal, a furnace 16 (particularly a rotary kiln) for burning raw meal to form clinker, and a cooler 18 for cooling the clinker burned in the furnace 16. The calciner 14 is, for example, referenced in [reference needed]. Figure 1 The apparatus described is for heat treatment.

[0072] The preheater 12 includes multiple cyclones 20 for separating the raw meal from the raw meal gas stream. For example, the preheater 12 has five cyclones 20 arranged as four cyclone stages, one below the other. The preheater 12 has a material inlet (not shown) for introducing the raw meal into the uppermost cyclone stage of the preheater 12, which includes two cyclones 20. The raw meal flows continuously through the cyclones 20 of the cyclone stage in a countercurrent manner with the exhaust gas from the furnace and / or calciner, and is thus heated.

[0073] The calcining furnace 14 is arranged between the last cyclone stage and the penultimate cyclone stage. The calcining furnace 14 has a riser line, specifically a riser line with at least one calcining furnace ignition system for heating the raw meal, such that the calcination of the raw meal takes place in the calcining furnace 14. Furthermore, the calcining furnace 14 has a fuel inlet for introducing fuel and an inert gas inlet for introducing inert gas into the riser line. The calcining furnace 14 also has a combustion gas inlet for introducing, for example, oxidized combustion gas into the riser line of the calcining furnace 14. The combustion gas is, in particular, oxygen-enriched furnace exhaust gas. The oxygen fraction of the combustion gas is, for example, at most 85% between furnace 16 and calcining furnace 14. The calcining furnace exhaust gas is introduced into preheater 12, preferably into the next cyclone stage, and exits preheater 12 as preheater exhaust gas 22 after the uppermost cyclone stage.

[0074] The calcining furnace 14 has, for example, two fuel distribution devices. It is also conceivable that the calcining furnace 14 may have only one or more fuel distribution devices. The two fuel distribution devices are optionally attached to the riser line 62 of the calcining furnace 14 at intervals from each other. Specifically, the fuel distribution devices are attached to the riser line 62 at different height levels. Each fuel distribution device is associated with a fuel inlet 48, 50 and an inert gas inlet 52, 54, respectively, such that fuel and inert gas are guided into the corresponding fuel distribution device. The arrangement of the fuel distribution devices is, for example, offset from each other by 180°. For example, the fuel distribution devices have means for conveying fuel, such as a conveying screw or chute. The introduction of one or more fuels can also be pneumatically performed, for example by means of inert gas conveying. The raw material inlet in the calcining furnace 14 is formed, for example, by the solids outlet of the next cyclone stage.

[0075] In the direction of raw meal flow, furnace 16 is connected downstream of preheater 12, such that raw meal preheated in preheater 12 and calcined in calcining furnace 14 is fed into furnace 16. The material inlet / gas outlet of furnace 16 is directly connected to the riser line of calcining furnace 14, allowing furnace exhaust gas to flow into calcining furnace 14 and subsequently into preheater 12. Furnace 16 is, for example, a rotary kiln with a rotating tube rotatable about its longitudinal axis, the rotating tube being arranged at a slightly downward angle. Furnace 12 has a furnace burner 28 and an associated fuel inlet 30 at the material outlet end within the rotating tube. The material outlet of furnace 16 is located at the end of the rotating tube opposite the material inlet 25, such that raw meal is conveyed into the rotating tube by the rotation of the rotating tube in the direction of the furnace burner 28 and the material outlet. The raw meal is burned within furnace 16 to form cement clinker. The sintering zone includes a rear region on the material outlet side of the rotating tube, preferably a third rear region in the material flow direction.

[0076] For example, fuel inlet 30 and inert gas inlet are associated with furnace burner 28, such that fuel and inert gas are directed to furnace burner 28. Fuel inlet 30 and inert gas inlet are formed independently of each other or as a common inlet into calcining furnace 14 or furnace 16. Inert gas is, for example, CO2 or water vapor. Inert gas can be used both as a conveying device and for ignition or control that affects the combustion process.

[0077] A cooler 18 for cooling clinker is adjacent to the material outlet of the furnace 16. The cooler 18 has a cooling gas chamber 34 in which the clinker is cooled by a stream of cooling gas. The clinker is conveyed through the cooling gas chamber 34 in the conveying direction F. The cooling gas chamber 34 has, for example, a first cooling gas chamber section 36 and a second cooling gas chamber section 38 adjacent to a first cooling gas chamber section 36 in the conveying direction F. The furnace 16 is connected to the cooler 18 via the material outlet of the furnace 16, and the clinker fired in the rotary kiln 20 falls into the cooler 18.

[0078] The first cooling gas chamber section 36 is arranged below the material outlet of the furnace 16, allowing clinker to fall from the furnace 16 into the first cooling gas chamber section 36. The first cooling gas chamber section 36 represents the inlet area of ​​the cooler 18 and preferably has a static grate that receives the clinker discharged from the furnace 16. Specifically, the static grate is entirely arranged within the first cooling gas chamber section 36 of the cooler 10. The clinker preferably falls directly from the furnace 16 onto the static grate. The static grate preferably extends fully at an angle of 10° to 35°, preferably 14° to 33°, and particularly 21° to 25° relative to the horizontal plane, allowing the clinker to slide along the static grate 40 in the conveying direction.

[0079] The second cooling gas chamber section 38 of the cooler 18 is adjacent to the first cooling gas chamber section 36. In the first cooling gas chamber section 36 of the cooler 18, the clinker is specifically cooled to a temperature below 1000°C, wherein the cooling is carried out in such a way that the liquid phase present in the clinker completely solidifies into a solid phase. Upon exiting the first cooling gas chamber section 36 of the cooler 18, the clinker is preferably supplied entirely in a solid phase and the temperature is at most 1150°C. In the second cooling gas chamber section 38 of the cooler 18, the clinker is further cooled, preferably to a temperature below 100°C. The second cooling gas flow can preferably be divided into multiple partial gas flows with different temperatures.

[0080] The static grid of the first cooling gas chamber section 36 has, for example, a channel through which cooling gas enters the cooler 18 and the clinker. The cooling gas is generated, for example, by at least one fan, blower, or pressurized vessel arranged below the static grid, such that the first cooling gas flow flows from below through the static grid into the first cooling gas chamber section 36. The first cooling gas flow is, for example, pure oxygen or a gas having a nitrogen fraction of 15 vol% or less and an oxygen fraction of 30 vol% or more. The first cooling gas flow flows through the clinker and subsequently into the furnace 16. The first cooling gas flow partially or completely forms, for example, the combustion gas of the furnace 16. The high proportion of oxygen in the combustion gas results in preheater exhaust gas, which is essentially composed of CO2 and water vapor, and has the advantage of eliminating the need for complex downstream purification methods for exhaust gas treatment. Furthermore, a reduction in the amount of process gas is achieved, allowing for a significantly smaller device size.

[0081] Inside the cooler 18, the clinker to be cooled moves in the conveying direction F. The second cooling gas chamber section 38 preferably has a dynamic, and particularly movable, grid adjacent to the static grid in the conveying direction F. For example, multiple fans are arranged below the dynamic grid, through which a second cooling gas flow blows from below at a dynamic rate. The second cooling gas flow is, for example, air.

[0082] exist Figure 1 For example, in this configuration, the crushing unit 48 is adjacent to the dynamic grid of the second cooling gas chamber section 38. At the crushing unit 48, another dynamic grid is adjacent below it. The cold clinker preferably leaves the cooler 18 at a temperature of 100°C or lower.

[0083] Cooler exhaust gas exits, for example, from the second cooling gas chamber section 38 and is directed to a separator, such as a cyclone separator, for separating solids. The solids are, for example, supplied back to the cooler 18. An air-to-air heat exchanger is connected downstream of the separator, such that the cooler exhaust gas preheats the air within the heat exchanger, which is, for example, supplied to the raw material mill.

[0084] Figure 3 Another exemplary embodiment of the apparatus 14 for heat treatment, particularly a calcining furnace, is shown, which at least partially corresponds to Figure 1 The device 14, wherein the same reference numerals denote the same elements. For example, two fuel distribution devices 64, 66 are attached to the riser line 62, through which fuel and inert gas are distributed together.

[0085] The riser line 62 of facility 14 has multiple different cross-sectional areas. Fuel distribution devices 64 and 66 of facility 14 are attached to the same side of the riser line 62, for example, without angular offset, but at different height levels. In the direction of gas flow within the riser line 62, raw material inlets 44 and 46 are preferably directly connected upstream and / or downstream of each fuel distribution device, respectively. Fuel inlets 48 and 50 and inert gas inlets 52 and 54 are each located at the fuel distribution devices 64 and 66 of the calciner 14, particularly at the same height as the respective fuel distribution devices.

[0086] Cross-sectional shrinkage ensures balanced mixing within the riser line, thus resulting in homogenized combustion and temperature distribution in both the longitudinal and transverse directions of the riser line in the calciner.

[0087] Figure 4 It shows according to Figures 1 to 3The details of device 14, particularly calcining furnace 14, are shown, wherein the same reference numerals denote the same elements. Device 14 has a guide element 73, which is attached, for example, within the riser line 62 in the left view and, for example, attached to the fuel distribution device of a special type of flame tube in the right view.

[0088] In the left view, the guide element 73 is arranged such that it causes a contraction in the cross-section of the riser line 62. The guide element 73 is specifically made in the form of a plate, chamber, or box and is attached to the inner wall of the riser line 62, and is attached to and opposite the fuel distribution device 66, for example, at the same height.

[0089] In the right figure, the guide element 73 has, for example, the form of a diffuser, wherein the cross-section of the guide element 73 increases in the direction of fuel flow. The guide element 73 is attached to the fuel distribution device, particularly to the orifice of the fuel distribution device's inlet riser 62, and is particularly capable of directionally introducing fuel into the riser 62. It is also conceivable that the guide element 73 terminates flush with the riser line and does not protrude therefrom, so that fuel can be uniformly introduced into the riser line 62.

[0090] The guiding element 73 is formed, for example, from a high-temperature resistant ceramic or fiber composite material.

[0091] Appendix Label Table

[0092] 10 Cement production facilities

[0093] 12 Preheater

[0094] 14 Equipment for heat treatment / calcining furnace

[0095] 16 furnaces

[0096] 18 Cooler

[0097] 20 Cyclone

[0098] 22 Preheater exhaust gas

[0099] 28 furnaces of burners or burner lances

[0100] Fuel inlet for 30 furnaces

[0101] 32 First Processing Area

[0102] 33 Second Processing Area

[0103] 34 Cooling Gas Chamber

[0104] 36 First Cooling Gas Chamber Section

[0105] 38 Second Cooling Gas Chamber Section

[0106] 40 Cross-sectional contraction

[0107] 42. Cross-sectional contraction

[0108] 44 First raw material inlet

[0109] 46 Second raw material inlet

[0110] 48 First Fuel Inlet

[0111] 50 Second fuel inlet

[0112] 52 First Inert Gas Inlet

[0113] 54 Second Inert Gas Inlet

[0114] 56 Temperature Measurement Unit

[0115] 58 Temperature Measurement Unit

[0116] 60 Adjustment Unit

[0117] 62. Lifting Pipeline

[0118] 64 Fuel distribution device

[0119] 66 Fuel distribution device

[0120] 73 Guide elements

Claims

1. An apparatus (14) for heat treating free-floating raw materials, comprising: The riser line (62) through which hot gas can flow. in, The riser line has at least one fuel inlet (48, 50) for introducing fuel into the riser line (62). Its features are, The riser line (62) has at least one raw material inlet for introducing raw material into the riser line (62), the raw material inlet being arranged upstream of the fuel inlet in the gas flow direction within the riser line (62), wherein the riser line (62) has at least one inert gas inlet (52, 54) connected to an inert gas source for introducing inert gas into the riser line (62); the riser line has at least two processing zones (32, 33) arranged continuously in the gas flow direction, the at least two processing zones having different diameters from each other, and wherein the pre-processing zone (32) in the gas flow direction has a raw material inlet (44) for introducing raw material into the pre-processing zone (32); the riser line (62) has at least one cross-sectional contraction (40, 42) between the processing zones (32, 33), the at least one cross-sectional contraction having a diameter smaller than that of the processing zones (32, 33).

2. The device (14) according to claim 1, wherein, The fuel inlet is located downstream of the pretreatment area (32).

3. The device (14) according to claim 2, wherein, The riser line (62) has an additional cross-sectional contraction (40) upstream of the pretreatment area (32).

4. The device (14) according to any one of claims 1-3, wherein, The lift line (62) has at least two raw material inlets for introducing raw material into the lift line (62), wherein each raw material inlet is arranged in a different processing area (32, 33) of the lift line (62).

5. The device (14) according to any one of claims 1-3, wherein, At least one of the fuel inlets (48, 50) has at least one or more fuel lines extending in the radial direction of the riser line into the riser line (62) through the riser line wall, and wherein at least one of the raw material inlets has at least one or more raw material lines extending in the radial direction of the riser line into the riser line through the riser line wall.

6. The device (14) according to claim 5, wherein, The fuel line extends into the riser line at an angle of 0° to ±50° relative to the raw material line.

7. The device (14) according to claim 6, wherein, The fuel line extends into the riser line at an angle of ±0° to ±30° relative to the raw material line.

8. The device (14) according to any one of claims 1-3, wherein, At least one temperature measuring unit (56, 58) is arranged in the riser line (62) to determine the temperature within the riser line (62), and wherein the device (14) has an regulating unit (60) connected to the temperature measuring unit (56, 58) to transmit the determined temperature, and wherein the regulating unit (60) is designed to regulate the amount of raw material, inert gas and / or fuel entering the riser line according to the determined temperature.

9. The device (14) according to any one of claims 1-3, wherein, The free-floating raw materials include cement raw materials and / or mineral products.

10. A method for heat-treating free-floating raw materials, comprising the following steps: - Fuel is introduced via fuel inlets (48, 50) into the riser line (62) used to guide hot gas, and - Introduce raw materials into the riser pipeline (62), Its features are, The raw material is introduced into the riser line (62) upstream of the fuel inlet (48, 50) in the gas flow direction, wherein an inert gas is introduced into the riser line (62); the riser line (62) has at least two processing zones (32, 33) arranged continuously in the gas flow direction, the at least two processing zones having different diameters from each other, and wherein the raw material is introduced into the pre-treatment zone (32) in the gas flow direction; the riser line (62) has at least one cross-sectional contraction (40, 42) between the processing zones (32, 33), the at least one cross-sectional contraction having a diameter smaller than that of the processing zones (32, 33).

11. The method according to claim 10, wherein, The temperature is determined by at least one temperature measuring unit (56, 58) within the riser line (62), and the amount of raw material, inert gas and / or fuel in the riser line is adjusted according to the determined temperature.

12. The method according to any one of claims 10-11, wherein, Fuel is introduced into the riser line (62) via at least two fuel inlets (48, 50) arranged continuously in the direction of gas flow, wherein more fuel is introduced in the direction of flow at one fuel inlet (48, 50) than at the other fuel inlet (48, 50).

13. The method according to any one of claims 10-11, wherein, A quantity of raw material corresponding to 20% to 60% of the total raw material amount introduced into the riser line (62) is introduced into the pretreatment area (32).

14. The method according to any one of claims 10-11, wherein, The free-floating raw materials include cement raw materials and / or mineral products.

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