Cement manufacturing equipment and methods for producing cement clinker

Abstract

The present invention relates to a cement production apparatus (10) comprising: - a preheater (12) for preheating raw meal; - a calcining furnace (14) for calcining the preheated raw meal; - a furnace (16) having a furnace burner (28) for calcining the raw meal to form cement clinker, wherein the furnace (16) has a combustion gas inlet for introducing combustion gas with an oxygen content of 30% to 75% into the furnace (16); and - a cooler (18) for cooling the cement clinker; wherein the calcining furnace (14) and the furnace (16) each have at least one fuel inlet (20) for introducing at least one fuel into the calcining furnace (14) and the furnace (16), wherein the calcining furnace (14) and the furnace (16) each have at least one inert gas inlet (64, 68) for introducing inert gas into the calcining furnace (14) and the furnace (16), respectively.

Description

Technical Field

[0001] The present invention relates to cement production equipment and a method for producing cement clinker, wherein an inert gas is introduced into at least one combustion process. Background Technology

[0002] It is known in the prior art that oxygen-rich gas for burning carbonaceous fuels is fed into the rotary kiln or calciner of cement production equipment. To reduce emissions and eliminate complex purification processes, for example, as known in DE 102018206673A1, combustion gases are used that are as rich in oxygen as possible, resulting in high CO2 content in the emissions. Document DE102018206673A1 discloses introducing oxygen-rich gas into the inlet region of a cooler to preheat the gas and cool the clinker.

[0003] When using oxygen-enriched combustion gas with a high oxygen content of at least 30% to 100%, very high temperatures will occur in the calcining furnace and within the furnace itself. If these high temperatures persist for an extended period or remain permanently in the area near the furnace walls, they can lead to damage to the furnace's inner walls. The melting stage of the calcined material can also be anticipated when the hot zone combines with the introduced hot material. Summary of the Invention

[0004] Based on this, the object of the present invention is to provide a cement production apparatus and a method for producing cement, wherein the safe operation of the furnace line is ensured while obtaining exhaust gas with a high CO2 content. An extended object is to introduce preheated raw meal into the calcining furnace in a uniformly distributed manner, allowing it to interact with the hot gas generated during calcination. A preferred object of the present invention is to achieve calcination in the furnace by selectively introducing fuel, oxygen-containing gas, and hot raw meal in stages, ensuring complete conversion of the introduced fuel, complete calcination of the introduced raw meal particles, and ensuring that solid particles are conveyed along the riser of the calcining furnace without overheating in the riser or causing solid particles to agglomerate along the riser.

[0005] According to the present invention, this objective is achieved by the cement production equipment and method of the present invention.

[0006] According to one aspect of the present invention, cement production equipment includes:

[0007] - A preheater for preheating raw materials.

[0008] - A calcining furnace used for calcining preheated raw materials.

[0009] - A furnace having a furnace burner (such as a burner lance) for firing calcined hot materials to form cement clinker, wherein the furnace has a combustion gas inlet for receiving combustion gases with an oxygen content of 30% to 100% into the furnace, and

[0010] - A cooler used to cool cement clinker.

[0011] -The calcining furnace and the furnace each have a fuel inlet for receiving fuel into the calcining furnace and the furnace, respectively.

[0012] The calcining furnace and the furnace each have an inert gas inlet for receiving inert gas into the calcining furnace and the furnace, respectively.

[0013] The preheater of a cement production plant preferably comprises multiple cyclone stages, each stage having at least one cyclone separator to separate solids from the gas stream. Compared to cement production plants that use air as the combustion gas, this invention enables the preheater to operate with a significantly smaller gas volume. For example, the exhaust gas volumetric flow rate after the preheater is approximately 0.50–0.90 Nm³. 3 per kilogram of clinker. Therefore, the ratio of raw meal feed to exhaust gas may be higher than that of equipment operated with air, and for example up to 3 kg solids per kilogram of gas, preferably 1.3 to 1.9 kg solids per kilogram of gas. In the preheater, the raw meal fed into the uppermost first cyclone stage is preheated in countercurrent flow with the furnace exhaust gas, and then passes through one cyclone stage after another.

[0014] A calcining furnace is located between the last and penultimate cyclone stages. This calcining furnace has an ascender into which raw materials are fed and heated for calcination. The calcining furnace may include one or more calcination locations. Preferably, the calcining furnace includes a fuel charging device comprising a fuel inlet and an inert gas inlet. The fuel charging device is, for example, tubular or formed as a radial protrusion on the ascender pipe of the calcining furnace. Preferably, the fuel charging device opens into the ascender pipe of the calcining furnace, allowing fuel and / or inert gas to be supplied into the ascender pipe via the fuel charging device. The fuel charging device is a heat treatment chamber used to heat the fuel and control the addition of fuel to the ascender.

[0015] Advantageously, the solid-to-gas ratio in the calciner is significantly higher compared to conventional systems using air as the oxidant. For example, a solid load exceeding 2 kg / kg of gas occurs locally, such as 2 to 8 kg / kg of gas. In the calciner, preferably the largest portion, exceeding 60%, such as about 80%, of the fuel heat is converted. Due to the introduction of raw material at the lower end of the calciner, although the initial oxygen concentration is 40-80%, which triggers intense combustion, there is still sufficient radiator to prevent overheating. If the combustion of blocky alternative fuels (e.g., with an edge length greater than 100 mm) is to be performed, a sloping zone with a longer fuel residence time should preferably be provided. Examples of such sloping zones are stair treads, push-type grilles, rear-push grilles, or other mechanical or pneumatic devices. These devices serve, for example, as combustion chambers, pre-combustion chambers, or only for the introduction of fuel drying and preheating or partial gasification. The fuel can be of any type in terms of particle size distribution and calorific value.

[0016] For example, the calcination reaction is carried out at a CO2 partial pressure of 10%-60% at the beginning of the calcination furnace and at a CO2 partial pressure of up to 98% at the end of the calcination furnace. Therefore, the calcination reaction is carried out at a higher temperature than in conventional equipment, at 700-1100°C, preferably 900-1000°C.

[0017] Raw materials, preheated in a preheater and calcined in a calcining furnace, are then fed into the furnace. The furnace is preferably a rotary furnace with a rotating tube that can rotate about its longitudinal axis and is preferably slightly inclined in the conveying direction of the material to be calcined, such that the material moves in the conveying direction due to the rotation of the rotating tube and gravity. The furnace preferably has a material inlet at one end for receiving the preheated and calcined raw materials and a material outlet at the end opposite the material inlet for discharging the calcined clinker into a cooler. At the end of the furnace on the material outlet side, a furnace head is preferably provided, comprising a furnace burner for burning the material and preferably at least one fuel inlet for receiving fuel (preferably via the furnace burner and / or via a fuel lance) into the furnace. The furnace preferably includes a sintering zone in which the material is at least partially melted and, 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 material conveying direction.

[0018] For example, all or part of the oxygen-containing combustion gases are directly introduced into the furnace head, which has, for example, a combustion gas inlet. Preferably, the combustion gases are introduced into the furnace, all or part, through the furnace's material outlet. The combustion gases supplied to the furnace have, for example, an oxygen content of more than 30% to 75%, preferably more than 95%. For example, the combustion gases consist entirely of pure oxygen, in which case the oxygen content of the combustion gases is 100%. The furnace burner can be, for example, a burner lance. A cooler for cooling cement clinker is preferably connected to the furnace's material outlet.

[0019] The cooler has a conveying device for conveying a large quantity of material through a cooling gas chamber in the conveying direction. The cooling gas chamber includes a first cooling gas chamber section with a first cooling gas flow and a second cooling gas chamber section adjacent to the first cooling gas chamber section in the conveying direction of the large quantity of material, with a second cooling gas flow. The cooling gas chamber is preferably bounded at the top by a cooling gas chamber top plate and at the bottom by dynamic and / or static grids (preferably the large quantity of material is located on the dynamic and / or static grids). The cooling gas flows through the entire chamber of the cooler, particularly above the large quantity of material. The cooling gas flow passes through the dynamic and / or static grids, particularly through the conveying device, through the large quantity of material, and enters the cooling gas chamber. The first cooling gas chamber section is preferably located directly after the cooler inlet in the flow direction of the large quantity of material to be cooled, particularly after the material outlet of the furnace. Preferably, clinker falls from the furnace into the first cooling gas chamber section.

[0020] The first cooling chamber section preferably has a static grid and / or a dynamic grid disposed below the material outlet of the furnace, such that the clinker leaving the furnace falls onto the static grid due to gravity. Preferably, only the first cooling gas flow enters the first cooling gas chamber section and is accelerated (e.g., by a fan or a pressure-loaded boiler or similar device). The second cooling gas chamber section is adjacent to the first cooling gas chamber section in the direction of bulk material transport and is preferably separated from the first cooling gas chamber section in terms of gas by a separation device. Preferably, only the second cooling gas flow accelerated by at least one fan enters the second cooling gas chamber section.

[0021] The second cooling gas chamber preferably has a dynamic grid for conveying large quantities of material through the cooling gas chamber. The first cooling gas stream flowing through the first cooling gas chamber is, for example, pure oxygen or a gas with a nitrogen and / or argon content of less than 35 vol%, particularly less than 21 vol%, preferably 15 vol% or less, and / or an oxygen content greater than 20.5%, particularly greater than 30% to 75%, preferably greater than 95%. The first cooling gas chamber is preferably directly connected to the furnace's material outlet, preferably to the furnace head, so that the cooling gas is heated in a cooler and then flows into the rotary furnace as combustion gas. The second cooling gas stream is, for example, air.

[0022] The cooler preferably has a separation device for separating the cooling gas chambers from each other in terms of gas.

[0023] Inert gases are, for example, CO2 or water vapor. Introducing an inert gas into the calcining furnace and / or calcining furnace provides the advantage of delaying, and in particular slowing, combustion, thereby preventing damage to the furnace and / or calcining furnace.

[0024] According to the first embodiment, the fuel inlet and the inert gas inlet are configured to be separate from each other and each forms an inlet into the furnace and / or calcining furnace. For example, the inert gas inlet is formed as an annular inlet surrounding the fuel inlet. The conduits for guiding the fuel and inert gas are formed, for example, as double pipes, preferably as concentric pipes with different diameters. Preferably, the inert gas is directly guided near the fuel inlet or fuel charging equipment. This makes it possible to economically supply expensive inert gas.

[0025] According to another embodiment, the fuel inlet and the inert gas inlet jointly form an inlet. The fuel and inert gas are preferably supplied to the calcining furnace or furnace via a common pipeline. This is less structurally complex and therefore more cost-effective.

[0026] According to further embodiments, the calcining furnace and / or the furnace each have multiple inert gas inlets, specifically for receiving different inert gases. It is also conceivable that the calcining furnace has multiple fuel charging devices, particularly two or three, each with its own inert gas inlet. Preferably, the fuel charging devices are spaced apart from each other at a distance along the length and / or width of the riser. For example, the fuel charging devices are arranged to be staggered from each other at an angle of 0°, preferably 60° to 270°, on the cross-section of the riser of the calcining furnace. Different types of fuel charging devices can be combined or arranged differently.

[0027] According to another embodiment, the calcining furnace has at least one raw material inlet for receiving raw materials into the calcining furnace, the raw material inlet being positioned upstream of the fuel inlet and the inert gas inlet along the flow direction of the gas within the calcining furnace. For example, the raw material inlet is located between two fuel charging devices or fuel inlets in the calcining furnace. Preferably, at least one raw material inlet is positioned upstream of the fuel inlet along the flow direction. This prevents the raw materials from overheating. The combustion zone generated by calcination in the calcining furnace can directly transfer heat to the raw material particles. The inert gas preferably also acts as a temperature absorber and also prevents the introduced fuel from spontaneously combusting directly at the burner or burner nozzle or at the inlet of the fuel charging device.

[0028] According to another embodiment, the calcining furnace has at least one, preferably two or more, raw material inlets for receiving raw materials into the calcining furnace, wherein at least one of the raw material inlets and preferably at least one fuel inlet are positioned upstream of the fuel inlet in the gas flow direction within the calcining furnace riser, particularly upstream of the fuel charging device. Preferably, at least one or all of the raw material inlets are positioned upstream of one or all of the fuel inlets. For example, the raw material inlet is positioned at a certain distance from the fuel charging device in the calcining furnace.

[0029] According to another embodiment, the cement production equipment includes a control device connected to a temperature measuring device within the calcining furnace and configured to control / regulate the amount of raw meal, inert gas, and / or fuel in the calcining furnace based on a temperature determined by the temperature measuring device. The temperature measuring device is preferably connected to the control device such that it transmits the determined temperature to the control device. The temperature measuring device is, for example, located downstream of one of the fuel charging devices. The calcining furnace, for example, has multiple temperature measuring devices, each connected to the control device to transmit the determined temperature. For example, the temperature measuring devices are connected downstream of each fuel charging device. It is also conceivable that multiple temperature measuring devices (preferably evenly distributed) are arranged within the riser of the calcining furnace.

[0030] For example, the amount of fuel in each fuel charging device is controlled based on temperature. This ensures uniform and controlled combustion within the calcining furnace with a uniform temperature distribution and avoids temperature spikes that could damage the calcining furnace or cause the material to melt.

[0031] For example, the control device is designed to compare a determined temperature with a predetermined setpoint, and if the determined temperature deviates from the setpoint, the control device controls the amount of fuel, inert gas, and / or raw material in the calcining furnace. For example, if the determined temperature exceeds the predetermined setpoint, the control device is designed to reduce the amount of fuel, increase the amount of raw material, and / or increase the amount of inert gas. For example, if the determined temperature is below the predetermined setpoint, the control device is designed to increase the amount of fuel, decrease the amount of raw material, and / or decrease the amount of inert gas.

[0032] According to a further embodiment, at least one cross-sectional contraction of the calcining furnace cross-section is disposed within the calcining furnace. For example, the calcining furnace has multiple cross-sectional contractions in the riser. This accelerates the flow within the riser and then slows it down, thereby preferably forming a calm flow region.

[0033] According to another embodiment, at least one guiding element for guiding the gas flow is disposed within the calcining furnace. This preferably achieves better mixing of the gas and raw material. This feature is particularly important for process control with high oxygen and low nitrogen content, because the reduced gas volume in the calcining furnace due to the lack of nitrogen results in a higher load after material supply compared to systems operating with air as the oxidant. Therefore, if the material is uniformly distributed across the cross-section of the calcining furnace's riser, it is advantageous for the load-bearing capacity of the particles. It prevents the material from settling into deeper downstream areas of the calcining furnace riser. The guiding element is designed, for example, as a plate, box, cone, and / or pyramid. Preferably, multiple guiding elements (e.g., uniformly spaced apart) are disposed within the riser. The guiding element is made, for example, of ceramic or ceramic fiber composite material. The guiding element is specifically disposed within the riser and / or in the fuel charging device. Preferably, the guiding element is disposed at the outlet of the fuel charging device into the riser, such that the fuel inlet into the riser is guided by the guiding element. Preferably, the guiding element extends from the fuel charging device into the riser. For example, the guiding element is formed and configured to guide the fuel at an angle to the inner wall of the riser. For example, the guiding elements form a diffuser with a cross-section that is wider than that of the fuel filling device.

[0034] According to another embodiment, the calcining furnace has multiple fuel charging devices, each including a fuel inlet and an inert gas inlet, and wherein a guide element is assigned to each fuel charging device. The corresponding fuel charging devices are, for example, positioned 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, particularly in the area of ​​the fuel charging device.

[0035] According to another embodiment, a combustion chamber is disposed between the furnace and the calcining furnace, or solely within the calcining furnace. The combustion chamber has a feed inlet, a fuel inlet (e.g., a fuel charging device), and an inert gas inlet. The combustion chamber may have, for example, a circular cross-section or a cyclone shape. It is also conceivable to design the combustion chamber as a simultaneous calcination reaction chamber, such that two calcining furnaces are connected in series or parallel. This provides regulation of fuel conversion and calcination within one or more calcining furnaces.

[0036] The present invention also includes a method for producing cement clinker, comprising the following steps:

[0037] -Preheat the raw material in the preheater.

[0038] - Calcination of preheated raw materials in a calcining furnace.

[0039] - Preheated and calcined raw materials are burned in a furnace equipped with a furnace burner to form cement clinker, wherein combustion gases with an oxygen content of 30% to 100% are supplied to the furnace, and

[0040] - The cement clinker is cooled in a cooler, where fuel is supplied to the furnace and calcining furnace.

[0041] Inert gas is supplied to each of the furnaces and calcining furnaces.

[0042] The above-described embodiments and advantages of the cement production equipment also apply to the method for producing cement clinker.

[0043] According to a further embodiment, the inert gas is supplied to the calcining furnace and / or furnace together with fuel and / or raw materials or separately. For example, at least two different inert gases are introduced into the calcining furnace and / or furnace.

[0044] According to another embodiment, the raw meal enters the calcining furnace ahead of the fuel and inert gas, along the gas flow direction within the furnace. For example, at least a portion of the raw meal and fuel are received into the calcining furnace upstream of the fuel charging device, along the gas flow direction within the furnace. Preferably, the raw meal has a temperature of 700°C to 900°C when received into the calcining furnace.

[0045] According to another embodiment, the temperature inside the calcining furnace is determined, and the amount of raw material, inert gas and / or fuel supplied to the calcining furnace is controlled / regulated according to the determined temperature.

[0046] According to another embodiment, a calm flow region is configured within the calcining furnace by means of at least one guiding element or at least one cross-sectional contraction of the calcining furnace cross section. Attached Figure Description

[0047] The invention will now be explained in more detail with reference to the accompanying drawings and several exemplary embodiments.

[0048] Figure 1 A schematic diagram of a cement production apparatus having a calcining furnace and a furnace according to an exemplary embodiment is shown.

[0049] Figure 2 A schematic diagram of a calcining furnace with an inert gas inlet according to another exemplary embodiment is shown.

[0050] Figure 3 A schematic diagram of a calcining furnace with an inert gas inlet according to another exemplary embodiment is shown.

[0051] Figure 4 A schematic diagram of a calcining furnace with guiding elements according to two other exemplary embodiments is shown. Detailed Implementation

[0052] Figure 1A cement production apparatus 10 is shown, which has a single-line preheater 12 for preheating raw meal, a calcining furnace 14 for calcining raw meal, a furnace 16, particularly a rotary furnace for calcining raw meal to form clinker, and a cooler 18 for cooling the clinker calcined in the furnace 16.

[0053] The preheater 12 includes multiple cyclones 20 for separating the raw meal from the raw meal gas flow. 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 receiving the raw meal into the uppermost cyclone stage of the preheater 12, which includes two cyclones 20. The raw meal flows countercurrently with the furnace and / or calcining furnace exhaust gases through the cyclones 20 of the cyclone stages and is thus heated. The calcining furnace 14 is located between the last and penultimate cyclone stages. The calcining furnace 14 has an ascender, particularly an ascender tube, which has at least one calcining furnace firing 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 includes a fuel inlet for receiving fuel and an inert gas inlet for introducing inert gas into the ascender. The calcining furnace 14 also includes a combustion gas inlet 26 for receiving oxygen-containing combustion gases into an ascender in the calcining furnace 14. The combustion gases are, in particular, oxygen-rich furnace exhaust gases. The oxygen content of the combustion gases is at most 85% between the furnace 16 and the calcining furnace 14. The calcining furnace exhaust gases are introduced into the preheater 12, preferably into the penultimate cyclone stage, and exit the preheater 12 as preheater exhaust gas 22 downstream of the uppermost cyclone stage.

[0054] Furnace 16 is connected downstream of preheater 12 along the raw material flow direction, such that the raw material preheated in preheater 12 and calcined in calcining furnace 14 flows into furnace 16. The material inlet / gas outlet 25 of furnace 16 is directly connected to the riser of calcining furnace 14, such that furnace exhaust gas flows into calcining furnace 14 and then into preheater 12. Furnace 16 is, for example, a rotary furnace, having a rotating tube rotatable about its longitudinal axis and arranged at a slightly downward angle. Furnace 16 has a furnace burner 28 and a fuel distribution 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 to the material inlet 25, such that the raw material is conveyed within the rotating tube to the furnace burner 28 and the material outlet by the rotation of the rotating tube. The raw material is calcined within furnace 16 to form cement clinker. Sintering zone 32 includes the rear region of the rotating tube on the material outlet side, preferably the rear third of the rear region in the material flow direction.

[0055] A cooler 18 for cooling clinker is connected 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 cooling gas flow. The clinker is conveyed through the cooling gas chamber 34 in the conveying direction F. The cooling gas chamber 34 has a first cooling gas chamber portion 36 and a second cooling gas chamber portion 38, the second cooling gas chamber portion being adjacent to the first cooling gas chamber portion 36 in the conveying direction F. The furnace 16 is connected to the cooler 18 via the material outlet of the furnace 16, so that the clinker fired in the rotary kiln 20 falls into the cooler 18.

[0056] A first cooling gas chamber 36 is disposed below the material outlet of the furnace 16, allowing clinker from the furnace 16 to fall into the first cooling gas chamber 36. The first cooling gas chamber 36 forms the inflow area of ​​the cooler 18 and preferably includes a static grid 40 that receives clinker leaving the furnace 16. Specifically, the static grid 40 is entirely disposed within the first cooling gas chamber 36 of the cooler 18. Preferably, the clinker from the furnace 16 falls directly onto the static grid 40. Preferably, the static grid 40 extends fully at an angle of 10° to 35°, preferably 14° to 33°, and particularly 21° to 25° with respect to the horizontal direction, allowing the clinker to slide along the static grid 40 in the conveying direction.

[0057] The first cooling gas chamber 36 is adjacent to the second cooling gas chamber 38 of the cooler 18. In the first cooling gas chamber 36 of the cooler 18, the clinker is specifically cooled to a temperature below 1000°C, wherein the cooling is performed in such a way that the liquid phase present in the clinker completely solidifies into a solid phase. When the clinker leaves the first cooling gas chamber 36 of the cooler 18, the clinker is preferably completely in a solid phase and at a temperature of 1000°C or lower. In the second cooling gas chamber 38 of the cooler 18, the clinker is further cooled, preferably to a temperature below 100°C. Preferably, the second cooling gas flow can be divided into multiple streams with different temperatures.

[0058] The static grid of the first cooling gas chamber 36 has, for example, channels for the cooling gas to enter the cooler 18 and the clinker. The cooling gas is generated, for example, by at least one fan, blower, or pressure pipe disposed below the static grid 40, such that a first cooling gas flow 42 flows from below through the static grid into the first cooling gas chamber 36. The first cooling gas flow 42 is, for example, pure oxygen or a gas containing less than 15 vol% nitrogen and more than 30 vol% oxygen. The first cooling gas flow 42 flows through the clinker and then into the furnace 16. The first cooling gas flow forms, for example, part or all of the combustion gas in the furnace 16. The high proportion of oxygen in the combustion gas results in the preheater exhaust gas consisting primarily of carbon dioxide and water vapor, and has the advantage of eliminating the need for expensive downstream purification processes for exhaust gas purification. Furthermore, a reduction in the amount of process gas is achieved, allowing for a significant reduction in equipment size.

[0059] Within the cooler 18, the clinker to be cooled moves along the conveying direction F. The second cooling gas chamber 38 preferably has a dynamic, particularly movable, grille 44 adjacent to the static grille 40 in the conveying direction F. Below the dynamic grille 44, for example, a plurality of fans are provided, through which a second cooling gas flow 46 blows from below over the dynamic grille 44. The second cooling gas flow 46 is, for example, air.

[0060] exist Figure 1 In this example, the pulverizing device 48 is connected to the dynamic grille 44 of the second cooling gas chamber 38. Another dynamic grille 50 is connected to the pulverizing device 48 below it. Preferably, the cold clinker 52 has a temperature of 100°C or lower when it leaves the cooler 18.

[0061] For example, cooler exhaust air 54 exits from the second cooling gas chamber section 38 and is fed into a separator 56 (e.g., a cyclone separator) to separate solids. For example, the solids are fed back to the cooler 18. An air-to-air heat exchanger 58 is connected downstream of the separator 56, such that the cooler exhaust air preheats the air within the heat exchanger 58, which is supplied, for example, to a raw material mill.

[0062] Figure 2 Shown according to Figure 1 Details of the cement production equipment 10, wherein the area not shown corresponds, for example, to Figure 1 The same area, and the same reference numerals denote the same elements. As an example, Figure 2The calcining furnace 14 shown has two fuel charging devices 60. It is also conceivable that the calcining furnace 14 may have exactly one fuel charging device 60 or more than two fuel charging devices 60. The two fuel charging devices 60 are mounted on the riser 62 of the calcining furnace 14 at a distance from each other. For example, fuel delivery devices 60 are mounted at different height levels on the riser 62. Each fuel charging device 60 is assigned a fuel inlet 24 and an inert gas inlet 64, such that fuel and inert gas are directed into the fuel charging device 60. For example, the fuel charging devices 60 are configured to be staggered from each other by 180°. For example, the fuel charging devices include means for transporting fuel, such as screw conveyors or chutes. One or more fuels may also be pneumatically supplied, for example, by means of inert gas delivery.

[0063] Figure 2 Further illustration shows that fuel inlet 30 and inert gas inlet 68 are assigned to furnace burner 28, such that fuel and inert gas are supplied to furnace burner 28. Fuel inlets 24, 30 and inert gas inlets 64, 68 are formed separately from each other, or as a common inlet to calcining furnace 14 or furnace 16. Inert gas is, for example, CO2 or water vapor. Inert gas can be used both as a transport medium and to influence ignition or control of the combustion process.

[0064] exist Figure 2 In the calciner 14, the raw material inlet 70 is formed, for example, by the solids outlet of the penultimate cyclone stage. The raw material inlet 70 is positioned, for example, between the two calciner burners 60. Alternatively, the raw material can preferably be supplied below each individual combustion zone downstream of the fuel inlet 30. Another possibility for supplying raw material and fuel is to employ a combustion chamber arranged parallel to the calciner's riser to simultaneously supply fuel and raw material in a low-oxygen zone. Preferably, the fuel is supplied centrally into a downwardly directed combustion chamber. Around the fuel supply, the raw material is supplied radially or circumferentially around the cylindrical combustion chamber, in such a way that the fuel is surrounded by a curtain of raw material. At the lower end of the combustion chamber, it connects to an upwardly directed riser of the calciner. The fuel enveloped by the raw material is introduced into the oxygen-enriched calciner stream, where it is ignited. The heat is directly consumed by the calcination reaction of the raw material.

[0065] For example, the calcining furnace 14 has a temperature measuring device 66 for determining the internal temperature of the calcining furnace 14. The cement plant 10 also includes a control device 72 connected to the temperature measuring device, such that the temperature measuring device 66 transmits the determined temperature to the control device 72. The control device 72 is connected to the fuel inlet 24, the raw material inlet 70, and / or the inert gas inlet 64, and is designed to control / regulate the amount of fuel, raw material, and / or inert gas in the calcining furnace 14 according to the determined temperature.

[0066] Figure 3 Showing Figure 1 and Figure 2 Another example of a calcining furnace 14, wherein the same reference numerals denote the same elements. The riser 62 of the calcining furnace 14 has multiple different cross-sectional areas. The fuel charging devices 60 of the calcining furnace 14 are attached to the same side of the riser 62, for example without angular offset, but at different height levels. In the gas flow direction within the riser 62, each fuel charging device 60 has a raw material inlet 70 located directly upstream and / or downstream of it. Fuel inlet 24 and inert gas inlet 64 are each located at the fuel charging device 60 of the calcining furnace 14, specifically at the same level as the corresponding fuel charging device 60.

[0067] The cross-sectional contraction ensures balanced mixing within the riser, resulting in uniform combustion and temperature distribution in both the longitudinal and transverse directions of the calcining furnace riser.

[0068] Figure 4 The details are of the calcining furnace 14, wherein the same reference numerals denote the same elements. The calcining furnace 14 has a guide element 73, which is attached, by way of example, within the riser 62 in the left schematic diagram and, by way of example, attached, in the form of a flue in the right schematic diagram, to the fuel charging device 60.

[0069] In the schematic diagram on the left, the guide element 73 is configured to cause a contraction in the cross-section of the riser 62. The guide element 73 is in particular plate-shaped, chamber-shaped, or box-shaped, and is attached to the inner wall of the riser 62, and for example, is attached at the same height and at a position opposite the fuel charging device 60.

[0070] In the schematic diagram on the right, the guide element 73 has an exemplary form of a diffuser, wherein the cross-section of the guide element 73 increases along the fuel flow direction. The guide element 73 is attached to the fuel charging device 60, particularly to the inlet of the fuel charging device 60 into the riser 62, and specifically allows for the targeted introduction of fuel into the riser 62. It is also conceivable that the guide element 73 is flush with the riser and does not extend into the riser, thereby allowing fuel to enter the riser 62 uniformly.

[0071] The guiding element 73 is formed, for example, from a high-temperature resistant ceramic or fiber composite material.

[0072] Reference Symbol List

[0073] 10 Cement Production Equipment

[0074] 12 Preheater

[0075] 14 Calcination furnace

[0076] 16 furnaces

[0077] 18 Cooler

[0078] 20 Cyclone

[0079] 22 Preheater exhaust gas

[0080] 24 Fuel inlet of the calcining furnace

[0081] 25 Material inlet to the furnace

[0082] 26 Combustion gas inlet of the calcining furnace

[0083] 28 furnaces of burners or burner lances

[0084] Fuel inlet for 30 furnaces

[0085] 32 Sintering Zone

[0086] 34 Cooling Gas Chamber

[0087] 36 First Cooling Gas Chamber

[0088] 38 Second Cooling Gas Chamber

[0089] 40 Static Grille

[0090] 42 First cooling gas flow

[0091] 44 Dynamic Grille

[0092] 46 Second Cooling Gas Flow

[0093] 48. Crushing device

[0094] 50 Dynamic Grille

[0095] 52 cold clinker

[0096] 54 Cooler exhaust air

[0097] 56 Separator

[0098] 58 Heat Exchanger

[0099] 60 Fuel charging equipment

[0100] 62. Ascending device of calcining furnace

[0101] 66 Temperature measuring device

[0102] 64 Inert gas inlet

[0103] 68 Inert gas inlet into the furnace

[0104] 70 Raw material inlet to the calcining furnace

[0105] 72 Control device

[0106] 73. Guiding element.

Claims

1. A cement production equipment (10), comprising: - A preheater (12) for preheating raw materials, - A calcining furnace (14) for calcining preheated raw materials. - A furnace (16) having a furnace burner (28) for burning raw materials to form cement clinker, wherein the furnace (16) has a combustion gas inlet for receiving combustion gases with an oxygen content of 30% to 100% into the furnace (16), and - A cooler (18) for cooling the cement clinker, - wherein the calcining furnace (14) and the furnace (16) respectively have fuel inlets for receiving fuel into the calcining furnace (14) and the furnace (16), Its features are, The calcining furnace (14) and the furnace (16) each have an inert gas inlet for receiving inert gas into the calcining furnace (14) and the furnace (16) respectively; wherein the calcining furnace (14) has at least two raw material inlets for receiving raw materials into the calcining furnace (14), and at least one of the raw material inlets is located upstream of the fuel inlet in the direction of gas flow within the calcining furnace (14).

2. The cement production equipment (10) according to claim 1, characterized in that, The fuel inlet and the inert gas inlet are configured to be separate from each other and each forms its own inlet.

3. The cement production equipment (10) according to claim 1, wherein, The fuel inlet and the inert gas inlet together form an inlet.

4. The cement production equipment (10) according to any one of claims 1-3, wherein, The calcining furnace (14) and / or the furnace (16) each have multiple inert gas inlets.

5. The cement production equipment (10) according to any one of claims 1-3, wherein the raw material inlet is located upstream of the fuel inlet and the inert gas inlet in the gas flow direction within the calcining furnace (14).

6. The cement production equipment (10) according to any one of claims 1-3, wherein, The cement production equipment (10) includes a control device (72) connected to a temperature measuring device (66) inside the calcining furnace (14) and configured to control / regulate the amount of raw materials, inert gas and / or fuel in the calcining furnace (14) according to the temperature determined by the temperature measuring device (66).

7. The cement production equipment (10) according to any one of claims 1-3, wherein, At least one cross-sectional contraction of the calcining furnace is disposed within the calcining furnace (14).

8. The cement production equipment (10) according to any one of claims 1-3, wherein at least one guiding element for guiding airflow and / or fuel is disposed within the calcining furnace (14).

9. The cement production equipment (10) according to claim 8, wherein, The calcining furnace (14) has a plurality of fuel charging devices (60), each of the fuel charging devices including a fuel inlet and an inert gas inlet, and wherein a guiding element is assigned to each fuel charging device (60).

10. The cement production equipment (10) according to any one of claims 1-3, wherein a combustion chamber is disposed between the furnace (16) and the calcining furnace (14), the combustion chamber having a raw material inlet, a fuel inlet and an inert gas inlet.

11. A method for producing cement clinker, comprising the following steps: -Preheat the raw material in the preheater (12), - Calcine the preheated raw material in a calcining furnace (14), - Preheated and calcined raw materials are burned in a furnace (16) equipped with a furnace burner (28) to form cement clinker, wherein combustion gases with an oxygen content of 30% to 100% are supplied to the furnace (16), and -The cement clinker is cooled in a cooler (18). Fuel is supplied to the furnace (16) and the calcining furnace (14). Its features are, Inert gas is supplied to the furnace (16) and the calcining furnace (14); the raw material is received in the calcining furnace (14) in the direction of gas flow within the calcining furnace (14) before the fuel and the inert gas.

12. The method according to claim 11, characterized in that, The inert gas is supplied together with or separately from the fuel to the calcining furnace (14) and / or the furnace (16).

13. The method according to any one of claims 11-12, wherein, Determine the temperature inside the calcining furnace, and control / adjust the amount of raw material, inert gas and / or fuel supplied to the calcining furnace (14) according to the determined temperature.

14. The method according to any one of claims 11-12, wherein, A calm flow zone is configured within the calcining furnace (14) by means of a guiding element or a cross-sectional contraction of the calcining furnace cross section.

Images