Equipment for the thermal treatment of dispersible raw materials and method for operating such equipment - Patents.com

Abstract

The present invention relates to an apparatus (14) for the thermal treatment of dispersible raw materials, in particular cement raw meal and / or mineral products, comprising a riser line (62) through which hot gases can flow, the riser line having at least one fuel inlet (48, 50) for the introduction of fuel into the riser line (62), the riser line (62) having at least one raw meal inlet (44, 46) for the introduction of raw meal into the riser line (62), the at least one raw meal inlet (44, 46) being arranged upstream of the fuel inlet (24) in a flow direction of gases in the riser line (62). The present invention also relates to a method for the thermal treatment of dispersible raw materials, in particular cement raw meal and / or mineral products, the method comprising the steps of introducing fuel into the riser line (62) via the fuel inlets (48, 50) for conducting hot gases and introducing raw meal into the riser line (62), the raw meal being introduced into the riser line (62) upstream of the fuel inlets (48, 50) in the flow direction of gases.

Description

[Technical field]

[0001] The present invention relates to an installation for the thermal treatment of floatable raw materials, in particular cement raw meal and / or mineral products. [Background technology]

[0002] For example, the use of calciners for the thermal treatment of raw materials, in particular in cement production plants, is known from the prior art. It is also known to introduce oxygen gas for burning carbonaceous fuels in rotary kilns or calciners of cement production plants. It is known, for example from DE 102018206673 A1, to use combustion gases that are as oxygen-rich as possible in order to reduce the amount of exhaust gases and to be able to dispense with complex purification methods, with the result that the CO2 content in the exhaust gases is high. DE 102018206673 A1 discloses introducing oxygen-rich gas into the cooler inlet region in order to preheat the gases and to cool the clinker.

[0003] When oxygen-enriched combustion gases with a high oxygen fraction of at least 30% to 100% are used, very high temperatures can occur in the calciner and furnace. If these high temperatures occur for longer periods or permanently in areas of the calciner close to the walls, damage to the inner walls of the calciner can result therefrom. If hot zones occur in combination with the introduced hot meal, a melting phase of the hot meal to be calcined can also be expected. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] DE 102018206673 Summary of the Invention [Problem to be solved by the invention]

[0005] It is then an object of the present invention to provide an installation for the thermal treatment of suspended solids, in which safe operation of the installation is guaranteed and at the same time exhaust gases having a high CO2 content are obtained. [Means for solving the problem]

[0006] This object is achieved according to the invention by an installation having the features of the independent apparatus claim 1 and by a method having the features of the independent method claim 11. Advantageous refinements result from the dependent claims.

[0007] An installation for the thermal treatment of floatable raw materials, in particular carbonate-containing materials, preferably cement raw meal and / or mineral products, according to a first aspect comprises a riser line through which hot gas can flow, the riser line having at least one fuel inlet for introducing fuel into the riser line, the riser line having at least one raw meal inlet for introducing raw meal into the riser line, arranged upstream of the fuel inlet in the flow direction of the gas in the riser line.

[0008] The equipment for thermal treatment of the floatable raw materials is, for example, a calciner, in particular for the calcination of preheated raw materials, for example for the production of cement, or for the decarburization of materials containing annealing losses. The equipment for thermal treatment of the floatable raw materials is, for example, arranged in an equipment for the production of calcined limestone or dolomite, for example for the preparation of recalcined residual material or FGD gypsum. The raw materials are, for example, a mixture of limestone or lime marl and clay, supplemented if necessary with iron ore, sand or further materials, or carbonate-containing materials such as limestone, dolomite, or mixtures containing them. The fuel is, 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 line through which the hot gas can flow, in particular from bottom to top. The riser line preferably has a hot gas inlet for introducing hot gas having 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 may have a combustion gas inlet arranged separately from the hot gas inlet for introducing combustion gas having an oxygen fraction of 20% to 100% by volume, in particular 30% to 80% by volume. The hot gas is preferably the exhaust gas of a combustion installation, for example a furnace of a cement manufacturing plant. The hot gas preferably has an oxygen concentration of 20% to 100% by volume, in particular 30% to 80% by volume. The riser line has, for example, a plurality of fuel inlets for introducing fuel into the riser line. Each fuel inlet is in particular provided with at least one or more fuel lines, which preferably extend in the radial direction of the riser line through the wall of the riser line. The riser line preferably has a number of raw meal inlets, with at least one raw meal inlet being arranged upstream of all the fuel inlets. The riser line preferably has two raw meal inlets arranged in succession in the gas flow direction. The at least one fuel inlet is preferably arranged between the two raw meal inlets.

[0010] By distributing the raw meal upstream of the fuel inlet, overheating of the raw meal in the riser line and thus, for example, damage to the inner wall of the riser line is prevented. The combustion zone created by the combustion of the fuel can release heat directly to the raw meal particles.

[0011] The solid-gas ratio in the installation, preferably in the calciner, is advantageously significantly higher compared to conventional installations using air as oxidant. For example, a local solid load of more than 1.5 kg per kilogram of gas, in particular 1.5-8 kg per kilogram of gas, is generated. A maximum portion of more than 60%, for example about 80%, of the fuel heat is preferably implemented in the installation. Due to the raw meal introduced upstream of the fuel inlet, a sufficient heat sink is provided to start the intensive combustion and prevent overheating, despite an initial oxygen concentration of 40-80%. When burning coarse alternative fuels, for example with edge lengths of >100 mm, it is preferable to provide a sloped area with a longer residence time of the fuel. Examples of such sloped areas are steps, push grates, reciprocating grates or other mechanical or pneumatic devices. These devices serve, for example, as a combustion chamber, a pre-combustion chamber or are used only for drying and preheating or partial gasification of the introduced fuel. The fuels can be of any type with regard to their particle size distribution and their heating value.

[0012] The calcination reaction may be carried out under CO2 partial pressures of 10% to 60% at the start of the calciner and up to 95% at the end of the calciner. It is therefore preferred that the calcination reaction is carried out at higher temperatures than in conventional equipment, between 700 and 1100°C, preferably between 900 and 1000°C.

[0013] According to a first embodiment, the riser line has at least one inert gas inlet for introducing an inert gas into the riser line. For example, the riser line has a plurality, in particular two or three, of inert gas inlets arranged in succession in the flow direction of the gas in the riser line. For example, the fuel inlet and the inert gas inlet are arranged separately from each other and each form an inlet to the riser line. The fuel inlet and the inert gas inlet preferably together form an inlet to the riser line. The fuel and the inert gas are preferably each supplied to the riser line in a common line. This is structurally less complicated and therefore more cost-effective. The inert gas is preferably additionally used as a temperature sink and further prevents spontaneous ignition of the fuel introduced directly at the fuel inlet, in particular at the burner orifice or burner lance orifice.

[0014] The inert gas is, for example, CO2 or water vapor. The supply of an inert gas to the equipment offers the advantage of retarding, in particular slowing down, the combustion so that damage to the equipment is prevented.

[0015] The riser line has, for example, several inert gas inlets, in particular for introducing different inert gases. It is also conceivable that the riser line has several fuel distributors, in particular two or three fuel distributors, each associated with an inert gas inlet. The fuel distributors are preferably arranged spaced apart from one another over the length and / or width of the riser line. For example, the fuel distributors are arranged offset from one another at an angle of 0°, preferably between 60° and 270°, over the cross section of the riser line of the calciner. Different types of fuel distributors can be combined with one another and can be arranged differently here.

[0016] According to a further embodiment, the riser line has at least two treatment zones arranged in succession in the gas flow direction, which treatment zones may have different diameters from each other, the front treatment zone in the gas flow direction having a raw meal inlet for introducing the raw meal into the front treatment zone, which preferably has a smaller diameter than the treatment zone arranged downstream.

[0017] The treatment zone is, for example, a part of the riser in which at least one inlet for introducing raw meal, fuel and / or inert gas is arranged. The front treatment zone preferably adjoins, in the gas flow direction, a cross-sectional constriction having a smaller, preferably constant diameter relative to the treatment zone. Each treatment zone has, for example, an intermediate zone with a constant diameter and zones arranged before and after, respectively, with a varying, decreasing or increasing diameter. In the gas flow direction, the treatment zone preferably has an expansion zone with a cross-section that increases in the flow direction. The zone with a constant cross-section adjoins an expansion zone. Preferably, a further zone with a decreasing or expanding cross-section adjoins the zone with a constant cross-section. The expansion zone with an increasing cross-section preferably has an opening angle of 10° to 60°, preferably 12° to 30°. In particular, the front part of the treatment zone in the flow direction adjoins, with an expanding cross-section, the cross-sectional constriction of the riser directly in the flow direction. The riser preferably has three or more, in particular three or four, treatment zones arranged in succession.

[0018] According to a further embodiment, the riser line has at least one cross-sectional constriction between the treatment zones, which has a smaller diameter than the treatment zone. The cross-sectional constriction is preferably a section of the riser with a constant diameter smaller than the section of the riser located immediately before and immediately after the cross-sectional constriction in the flow direction. The cross-sectional constriction is, for example, located between two adjacent treatment zones. Such a cross-sectional constriction ensures a local acceleration of the flow, which is decelerated in the adjacent zone with a larger diameter in the flow direction. This ensures a thorough mixing of the gas with the raw meal.

[0019] According to a further embodiment, the fuel inlet is located downstream of the front treatment region.

[0020] For example, the installation may have two or more fuel inlets, all located downstream of a pre-treatment region. The inlet or inlets for introducing the raw meal into the riser line are preferably located in the pre-treatment region.

[0021] According to a further embodiment, the riser line has a further cross-sectional constriction upstream of the front treatment zone. The front treatment zone is preferably arranged between the two cross-sectional constrictions. At least a part of the raw meal is preferably distributed to the front treatment zone, the cross-sectional constriction resulting in a reduction in the flow velocity in the treatment zone and thus a better thorough mixing of the raw meal with the hot gas. Localized regions with very high temperatures are avoided and thus damage to the riser wall is prevented.

[0022] According to a further embodiment, the riser line has at least two raw meal inlets for introducing the raw meal into the riser line, the raw meal inlets being respectively arranged in different treatment zones of the riser line. In particular, the raw meal inlets are arranged at different height levels, preferably successively in the flow direction of the riser line. Preferably, each treatment zone has at least one raw meal inlet. This allows for a staged distribution of the raw meal into the riser line, so that the raw meal is introduced into different zones of the riser line and in each case optimally mixed with the hot gas.

[0023] According to a further 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 at least one of the raw meal inlets has at least one or more raw meal lines extending in the radial direction of the riser line, the at least one or more raw meal lines extending through the riser line wall into the riser line. According to a further embodiment, the fuel lines extend into the riser line at an angle of 0° to 50°, in particular 20° to 30° to the raw meal lines.

[0024] According to a further embodiment, at least one temperature measuring unit for ascertaining the temperature inside the riser line is arranged inside the riser line, and the installation has a regulating unit connected to the temperature measuring unit for transmitting the ascertained temperature, which is designed to regulate the amount of raw meal, inert gas and / or fuel in the riser line depending on the ascertained temperature. Preferably, the raw meal inlet, the fuel inlet and / or the inert gas inlet each have a metering element such as a flap or a valve for setting the amount of raw meal, inert gas or fuel introduced into the riser line. Each metering element is preferably connected to the regulating unit to set the amount of raw meal, inert gas or fuel introduced into the riser line.

[0025] The temperature measuring units preferably comprise thermocouples or acoustic gas temperature measurements. The temperature measuring units are particularly mounted on the inner wall of the riser line and are preferably designed to ascertain the gas temperature inside the riser line. For example, the riser line has two temperature measuring units arranged successively in the flow direction. In particular, the temperature measuring units are each associated with one fuel inlet and are arranged downstream, preferably directly or in the immediate surroundings of the fuel inlet. The temperature measuring units are particularly designed and designed to ascertain the temperature at or near the fuel inlet.

[0026] The regulating unit is preferably designed to compare the ascertained temperature with a predefined temperature limit or temperature limit range and to increase or decrease the amount of fuel, raw meal and / or inert gas in the riser line if the ascertained temperature deviates from the temperature limit or temperature limit range. For example, if the temperature ascertained by the temperature measuring unit exceeds the temperature limit or temperature limit range, the amount of fuel flowing into the riser line, in particular through the fuel inlet associated with the respective temperature measuring unit, is reduced. For example, if the temperature ascertained by the temperature measuring unit falls below the temperature limit or temperature limit range, the amount of fuel flowing into the riser line through the fuel inlet associated with the respective temperature measuring unit is increased.

[0027] In particular, the regulating unit is designed to decrease or increase the amount of inert gas in the riser line if the ascertained temperature deviates from the temperature limit value or temperature limit range. For example, if the ascertained temperature exceeds the temperature limit value or temperature limit range, the amount of inert gas that is preferably flowing into the riser line through the inert gas inlet associated with the respective temperature measurement unit is decreased. For example, if the ascertained temperature falls below the temperature limit value or temperature limit range, the amount of inert gas that is preferably flowing into the riser line through the inert gas inlet associated with the respective temperature measurement unit is increased. The inert gas inlet or fuel inlet associated with each temperature measurement unit is preferably the inert gas inlet and fuel inlet closest to the respective temperature measurement unit.

[0028] For example, if the temperature ascertained by the temperature measuring unit exceeds a temperature limit value or temperature limit range, the amount of raw meal flowing into the riser line through at least one of the raw meal inlets is increased. The total amount of raw meal flowing into the riser line preferably remains constant, so that the amount of raw meal is reduced at one raw meal inlet and increased accordingly at at least one further raw meal inlet. For example, if the temperature ascertained by the temperature measuring unit falls below a temperature limit value or temperature limit range, the amount of raw meal flowing through at least one of the raw meal inlets is reduced.

[0029] At least one guide element for guiding the gas flow is arranged inside the riser line of the installation, for example. Thus, a more complete mixing of the gas with the raw meal is preferably achieved. This function is particularly important for process control using high oxygen content and low nitrogen content, in that the absence of nitrogen fraction reduces the amount of gas in the installation, resulting in a higher load after the introduction of the material than in an installation operated with air as oxidant. Therefore, due to the carrying capacity of the particles, it is advantageous that the material is uniformly distributed over the cross section of the riser line of the calciner. Sedimentation of the raw meal into zones of the riser line located downstream is prevented. The guide element is designed, for example, as a plate, box, cone and / or pyramid. A plurality of guide elements are preferably arranged inside the riser line, for example, uniformly spaced from one another. The guide element is formed, for example, from a ceramic or ceramic fiber composite material. The guide element is arranged, in particular, inside the riser line and / or at the fuel inlet. One guide element is preferably arranged at the outlet of the fuel outlet in the riser line, and the introduction of fuel into the riser line is guided by the guide element. The guide element preferably extends from the fuel inlet into the riser line. The guide element is, for example, designed and arranged to guide the fuel at an angle to the inner wall of the riser. For example, the guide element forms a diffuser with an expanding cross section toward the fuel inlet.

[0030] For example, the installation may have several fuel distributors, each with a fuel inlet and an inert gas inlet, and a guide element associated with each fuel distributor, each of which may be, for example, located at the same height level as the guide element or directly connected upstream or downstream of the guide element, allowing an optimized distribution of the raw meal and the inert gas inside the riser line, especially in the region of the fuel distributor.

[0031] The above-mentioned installation is arranged, for example, in a cement factory. Such a cement manufacturing plant preferably comprises: a preheater for preheating the raw meal; a calciner for calcining the preheated raw meal, the calciner being the equipment described above; a furnace burner, for example a furnace having a burner lance for burning hot meal to form cement clinker, the furnace having a combustion gas inlet for introducing a combustion gas having an oxygen fraction of 30% to 100% into the furnace; a cooler for cooling the cement clinker; Equipped with The calciner and furnace each have at least one fuel inlet for introducing fuel into the calciner and furnace.

[0032] The calciner and / or furnace each have at least one inert gas inlet for introducing inert gas into the calciner and / or furnace, respectively. The calciner is in particular the above-mentioned installation for the heat treatment.

[0033] The preheater of the cement manufacturing plant preferably comprises a number of cyclone stages, each having at least one cyclone for separating solids from the gas stream. Between the last and next to last cyclone stages is located a calciner having a riser line in which the raw meal is heated by a calciner firing system, which may consist of one or more firing points.

[0034] The raw meal preheated in the preheater and calcined in the calciner is subsequently fed into the furnace. The furnace is preferably a rotary kiln with a rotary tube rotatable about its longitudinal axis and preferably slightly inclined in the conveying direction of the material to be calcined, so that the material moves in the conveying direction by the rotation of the rotary tube and by gravity. The furnace preferably has a material inlet at one of its ends for introducing the preheated calcined raw meal and a material outlet at the end opposite the material inlet for discharging the calcined clinker into the cooler. A furnace head is preferably arranged at the material outlet end of the furnace, which has furnace burners for calcining the material and at least one fuel inlet for introducing fuel into the furnace, preferably via the furnace burners and / or a fuel lance. The furnace preferably has a sintering zone in which the material is at least partially melted, in particular having a temperature between 1500°C and 1900°C, preferably between 1450°C and 1750°C. The sintering zone comprises, for example, the furnace head, preferably the rear third of the furnace in the conveying direction of the material.

[0035] The oxygen-containing combustion gas is for example fully or partially introduced directly into the furnace head, which for example has a combustion gas inlet. The combustion gas is preferably fully or partially introduced into the furnace via the material outlet of the furnace. The combustion gas supplied to the furnace has for example an oxygen fraction of more than 30% to 75%, preferably more than 95%. The combustion gas consists for example of completely pure oxygen, in which case the oxygen fraction of the combustion gas is 100%. The furnace burner can for example be a burner lance. A cooler for cooling the cement clinker is preferably adjacent to the material outlet of the furnace.

[0036] The cooler has a conveyor section for conveying the bulk material through the cooling gas chamber in the conveying direction. The cooling gas chamber comprises a first cooling gas chamber section with a first cooling gas flow and a second cooling gas chamber section adjacent thereto in the conveying direction of the bulk material and with a second cooling gas flow. The cooling gas chamber is preferably defined at the top by a cooling gas chamber cover and at the bottom by a dynamic and / or stationary grate, preferably by the bulk material resting thereon. The cooling gas chamber is in particular the entire chamber of the cooler above the bulk material through which the cooling gas flows. The cooling gas flow flows through the dynamic and / or stationary grate, in particular through the conveyor unit, through the bulk material and into the cooling gas chamber. The first cooling gas chamber section is preferably arranged in the flow direction of the bulk material to be cooled immediately after the cooler inlet, in particular the material outlet of the furnace. The clinker preferably falls from the furnace into the first cooling gas chamber section.

[0037] Preferably, only the first cooling gas flow enters the first cooling gas chamber section, which is accelerated, for example, by a fan or a pressurized container or another corresponding device. The second cooling gas chamber section is adjacent to the first cooling gas chamber section in the bulk material conveying direction and is preferably separated from the first cooling gas chamber section in terms of gas technology by a separating device. Preferably, only the second cooling gas flow, which is accelerated, for example, by at least one fan, flows through the second cooling gas chamber section.

[0038] The first cooling gas flow through the first cooling gas chamber section is, for example, pure oxygen or a gas with a proportion of nitrogen and / or argon of less than 35% by volume, in particular less than 21% by volume, preferably less than 15% by volume, and / or a proportion of oxygen of more than 20.5%, in particular between 30% and 75%, preferably more than 95%. The first cooling gas chamber section is preferably directly adjacent to the material outlet of the furnace, preferably the furnace head, so that the cooling gas is heated in the cooler and subsequently flows into the rotary kiln and is then used as combustion gas. The second cooling gas flow is, for example, air.

[0039] The present invention also includes a method for thermally treating a floatable raw material, in particular a cement raw meal and / or a mineral product, the method comprising the steps of: introducing fuel into the riser line via a fuel inlet for conducting the hot gas; introducing raw meal into the riser line, the raw meal being introduced into the riser line upstream of the fuel inlet in a gas flow direction; Includes.

[0040] The advantages and embodiments described with reference to the installation apply analogously to the method for the thermal treatment of raw materials according to the method.

[0041] Hot gas is preferably introduced into the riser line via a hot gas inlet, in particular from below, the hot gas having an oxygen concentration in particular between 20% and 100% by volume, in particular between 30% and 90% by volume. Combustion gas may be introduced into the riser line separately from the hot gas, the combustion gas having an oxygen fraction in particular between 20% and 100% by volume, in particular between 30% and 90% by volume. In the riser line, for example, a CO2 partial pressure of 10% to 60% is set at the start of the riser line and a CO2 partial pressure of up to 95% is set at the end of the riser line. Preferably, a temperature of 700 to 1100 ° C, preferably 900 to 1000 ° C, is set inside the installation.

[0042] According to one embodiment, an inert gas is introduced into the riser line. The inert gas is preferably introduced into the riser line downstream of the raw meal inlet.

[0043] According to a further embodiment, the riser line has at least two treatment zones arranged in succession in the gas flow direction, preferably having mutually different diameters, and the raw meal is introduced into the front treatment zone in the gas flow direction.

[0044] According to a further embodiment, the temperature is ascertained by at least one temperature measuring unit in the riser line and the amount of raw meal, inert gas and / or fuel in the riser line is adjusted depending on the ascertained temperature.

[0045] According to a further embodiment, the fuel is introduced into the riser line via at least two fuel inlets arranged in succession in the flow direction of the gas, with more fuel being introduced into the front fuel inlet in the flow direction than into the other fuel inlets, the amount of fuel in the front fuel inlet in the flow direction being preferably about 20 to 120%, in particular 50 to 100%, of the total amount of fuel supplied to the riser line.

[0046] According to a further embodiment, an amount of raw meal is introduced into the front treatment zone that corresponds to about 20% to 60% of the total amount of raw meal introduced into the riser line.

[0047] The invention is explained in more detail below on the basis of several exemplary embodiments with reference to the accompanying drawings. [Brief description of the drawings]

[0048] [Figure 1] FIG. 1 is a schematic diagram of a facility for thermal treatment of feedstock, according to an exemplary embodiment. [Diagram 2] FIG. 2 is a schematic diagram of a cement production plant having a heat treatment facility according to FIG. 1 or FIG. [Diagram 3] FIG. 3 is a schematic diagram of an installation for thermal treatment of feedstock according to another exemplary embodiment. [Figure 4] FIG. 4 is a schematic diagram of a detail of an installation for heat treatment according to FIG. 3 according to a further exemplary embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] Figure 1 shows an installation 14 for the thermal treatment of floatable raw materials, in particular cement raw meal and / or mineral products. Such an installation 14 is in particular a calciner used in cement production plants for calcining raw meal, e.g. preheated. The raw materials are preferably cement raw meal, mineral materials, e.g. limestone, ore or clay. The raw meal is preferably a mixture of limestone or limestone marl and clay, supplemented if necessary with iron ore, sand or further materials, or carbonate-containing materials such as limestone, dolomite, or mixtures containing them.

[0050] The installation 14 comprises a riser line 62 through which hot gases can flow, preferably from bottom to top. The riser line 62 extends, for example, vertically and has, in particular in its lower region, an inlet for introducing hot gases, for example exhaust gases of a combustion unit, such as a rotary kiln of a cement manufacturing plant. The flow direction of the hot gases in the riser line 62 is indicated by arrows at the lower and upper ends of the riser line 62.

[0051] The riser line 62 has a number of different diameters. For example, the riser line 62 has two treatment zones 32, 33 arranged in succession in the gas flow direction. The first front treatment zone 32 is arranged in the flow direction ahead of the second treatment zone 33, the diameter of the first treatment zone 32 being, for example, smaller than the diameter of the second treatment zone 33. For example, a part of the riser line 62 having a larger diameter than the second treatment zone 33 is adjacent to the second treatment zone 33. Each treatment zone has, for example, an essentially constant diameter. Between the two treatment zones 32, 33, the riser line 62 has a cross-sectional constriction 40, in particular a zone having a smaller diameter than the treatment zones 32, 33 adjacent thereto. For example, each of the treatment zones 32, 33 has a part having an essentially constant diameter and a part having a varying diameter adjacent thereto, for example decreasing or increasing. Upstream of the first treatment zone 32, the riser line 62 has a further cross-sectional constriction 42, which the first treatment zone 32 of the riser line 62 preferably directly adjoins. The diameter of the cross-sectional constriction 42 corresponds, by way of example, to the diameter of the cross-sectional constriction 40 arranged between the two treatment zones 32, 33. Each treatment zone 32, 33 has at least one inlet, in particular for introducing raw meal, fuel or inert gas.

[0052] At the lower end of the riser line 62, for example at the cross-sectional narrowing 42, a furnace inlet of a rotary kiln of a cement manufacturing plant is adjacent, and the furnace exhaust gas is led to the riser line through the furnace inlet. It is also conceivable to connect the lower end of the riser line 62 to an exhaust gas pipe of a lime burning facility.

[0053] The equipment 14 has a first raw meal inlet 44 attached to the first processing area 32 of the riser line 62. The raw meal inlet 44 preferably has at least one or more raw meal lines, which run in the radial direction of the riser line and are arranged, for example, circumferentially around the riser line at one height level. Each of the raw meal lines preferably extends through the wall of the riser line 62 into the first processing area 32. The first raw meal inlet 44 is arranged, for example, vertically in the center of the first processing area 32. The equipment 14 has a second raw meal inlet 46, which is designed, for example, identical to the first raw meal inlet 44 and is preferably arranged in the center in the second processing area 33.

[0054] The installation 14 has, for example, two fuel inlets 48, 50, both arranged in the second treatment area 33. Each of the fuel inlets 48, 50 has, for example, at least one or more fuel lines, which extend in the radial direction of the riser line 62 and are arranged, for example, circumferentially around the riser line 62 at one height level. Each of the fuel lines preferably extends through the wall of the riser line 62 into the second treatment area 33. The fuel inlets 48, 50 are arranged successively in the flow direction of the gas in the second treatment area 33 at different height levels of the riser line 62. For example, the first fuel inlet 48 is arranged in the lower area, in particular in the inlet area, and the second fuel inlet 50 is arranged in the upper area, in particular in the outlet area, of the second treatment area 33. The first fuel inlet 48 is arranged, for example, upstream of the second raw meal inlet 46 and the second fuel inlet 50 is arranged, for example, downstream of the second raw meal inlet 46.

[0055] The installation 14 has, for example, two inert gas inlets 52, 54, each opening into the second processing area 32. The first inert gas inlet 52 is, for example, arranged upstream of the second raw meal inlet 46, and the second inert gas inlet 54 is, for example, arranged downstream of the second raw meal inlet 46.

[0056] The installation 14 further comprises two temperature measurement units 56, 58 both mounted inside the second processing area 33. For example, the temperature measurement units 56, 58 are each associated with one fuel inlet 48, 50 and are positioned downstream, preferably directly or immediately surrounding the fuel inlets 48, 50. The first temperature measurement unit 56 is, for example, associated with the first fuel inlet 48 and the second temperature measurement unit 58 is associated with the second fuel inlet 50.

[0057] The installation 14 further comprises a regulation unit 60 connected to the temperature measurement unit 58 for transmitting the ascertained temperature. The regulation unit 60 is preferably connected to the first and second raw meal inlets 44, 46 and regulates the amount of raw meal flowing through the respective raw meal inlets 44, 46 into the riser line 62. The regulation unit 60 may be connected to the fuel inlets 48, 50 and / or the inert gas inlets 52, 54 and regulates the amount of fuel and / or inert gas flowing through the respective fuel inlets 48, 50 and / or the inert gas inlets 52, 54 into the riser line 62. The raw meal inlets 46, 48, the fuel inlets 48, 50 and / or the inert gas inlets 52, 52 comprise metering units, for example flaps or valves, through which the respective amounts of raw meal, fuel and inert gas can be regulated. The metering units are preferably connected to the regulation unit.

[0058] The regulation unit 60 compares the ascertained temperature with, preferably, a predefined temperature limit or temperature limit range. In particular, the regulation unit 60 is designed to decrease or increase the amount of fuel in the riser line 62 if the ascertained temperature deviates from the temperature limit or temperature limit range. For example, if the temperature ascertained by one of the temperature measurement units 56, 58 exceeds the temperature limit or temperature limit range, the amount of fuel flowing into the second treatment area 33 through the fuel inlet 48, 50 associated with the respective temperature measurement unit 56, 58 is decreased. For example, if the temperature ascertained by one of the temperature measurement units 56, 58 is below the temperature limit or temperature limit range, the amount of fuel flowing into the second treatment area 33 through the fuel inlet 48, 50 associated with the respective temperature measurement unit 56, 58 is increased.

[0059] In particular, the adjustment unit 60 is designed to decrease or increase the amount of inert gas in the riser line 62 if the ascertained temperature deviates from the temperature limit value or temperature limit range. For example, if the temperature ascertained by one of the temperature measurement units 56, 58 exceeds the temperature limit value or temperature limit range, the amount of inert gas flowing through the inert gas inlet 52, 54 associated with the respective temperature measurement unit 56, 58 into the second processing area 33 is decreased. For example, if the temperature ascertained by one of the temperature measurement units 56, 58 falls below the temperature limit value or temperature limit range, the amount of inert gas flowing through the inert gas inlet 52, 54 associated with the respective temperature measurement unit 56, 58 into the second processing area 33 is increased. The inert gas inlet 52, 54 or fuel inlet 48, 50 associated with the respective temperature measurement unit 56, 58 is preferably the inert gas inlet 52, 64 and fuel inlet 48, 50 closest to the respective temperature measurement unit 56, 58.

[0060] In particular, the adjustment unit 60 is designed to decrease or increase the amount of raw meal in the riser line 62 if the ascertained temperature deviates from the temperature limit value or temperature limit range. For example, if the temperature ascertained by one of the temperature measurement units 56, 58 exceeds the temperature limit value or temperature limit range, the amount of raw meal flowing through at least one of the raw meal inlets 44, 46 is increased. Preferably, the total amount of raw meal flowing through the riser line 62 remains constant, so that the amount of raw meal is decreased at one of the raw meal inlets 44 and increased accordingly at at least one further raw meal inlet 46. For example, if the temperature ascertained by one of the temperature measurement units 56, 58 falls below the temperature limit value or temperature limit range, the amount of raw meal flowing through at least one of the raw meal inlets 44, 46 is decreased. For example, if the limit value or limit range is not reached, the amount of raw meal flowing through the second raw meal inlet 46 into the second processing area 33 is decreased and the amount of raw meal through the first raw meal inlet 44 is increased accordingly.

[0061] Figure 2 shows a cement production plant 10 having a single strand preheater 12 for preheating the raw material, a calciner 14 for calcining the raw meal, a furnace 16, in particular a rotary kiln for calcining the raw meal to form clinker, and a cooler 18 for cooling the clinker calcined in the furnace 16. The calciner 14 is, for example, an installation for heat treatment as described with reference to Figure 1.

[0062] The preheater 12 comprises a number of cyclones 20 for separating the raw meal from the raw meal gas stream. For example, the preheater 12 may have five cyclones 20 arranged in four cyclone stages below one another. The preheater 12 has a material inlet (not shown) for introducing the raw meal into the top cyclone stage of the preheater 12 which comprises two cyclones 20. The raw meal flows successively through the cyclones 20 of the cyclone stages countercurrent to the furnace and / or calciner exhaust gases and is therefore heated.

[0063] The calciner 14 is arranged between the last cyclone stage and the penultimate cyclone stage. The calciner 14 has a riser line, in particular a riser, with at least one calciner firing system for heating the raw meal, so that calcination of the raw meal takes place in the calciner 14. Furthermore, the calciner 14 has a fuel inlet for introducing fuel and an inert gas inlet for introducing an inert gas into the riser line. The calciner 14 further has a combustion gas inlet for introducing, for example, oxygenated combustion gas into the riser line of the calciner 14. The combustion gas is in particular an oxygen-enriched furnace exhaust gas. The oxygen fraction of the combustion gas is, for example, up to 85% between the furnace 16 and the calciner 14. The calciner exhaust gas is introduced into the preheater 12, preferably the penultimate cyclone stage, and leaves the preheater 12 after the top cyclone stage as the preheater exhaust gas 22.

[0064] The calciner 14 has, for example, two fuel distributors. It is also conceivable that the calciner 14 has exactly one fuel distributor or three or more fuel distributors. The two fuel distributors may be mounted at a distance from each other on the riser line 62 of the calciner 14. In particular, the fuel distributors are mounted on the riser line 62 at different height levels. Each fuel distributor is associated with one fuel inlet 48, 50 and one inert gas inlet 52, 54, respectively, so that the fuel and the inert gas are led to the respective fuel distributor. The fuel distributors are, for example, positioned offset by 180° with respect to each other. For example, the fuel distributors have means for transporting the fuel, such as a conveyor screw or a chute. The introduction of the fuel or fuels can also be carried out pneumatically, for example by conveying with an inert gas. The raw meal inlet in the calciner 14 is, for example, formed by the solids outlet of the penultimate cyclone stage.

[0065] In the flow direction of the raw meal, downstream of the preheater 12 is connected a furnace 16 into which the raw meal preheated in the preheater 12 and calcined in the calciner 14 flows. The material inlet / gas outlet of the furnace 16 is directly connected to the riser line of the calciner 14 so that the furnace exhaust gas flows into the calciner 14 and then into the preheater 12. The furnace 16 is, for example, a rotary kiln having a rotating tube rotatable about its longitudinal axis and arranged at a slight inclination angle. The furnace 12 has a furnace burner 28 at the inner end of the rotating tube at the material outlet side and an associated fuel inlet 30. The material outlet of the furnace 16 is located at the end of the rotating tube opposite the material inlet 25, so that the rotation of the rotating tube transports the raw meal in the direction of the furnace burner 28 and the material outlet. The raw meal is fired in the furnace 16 to form cement clinker. The sintering zone comprises the rear region of the rotary tube on the material outlet side, preferably the rear third in the material flow direction.

[0066] For example, a fuel inlet 30 and an inert gas inlet are associated with the furnace burner 28 so that the fuel and the inert gas are guided to the furnace burner 28. The fuel inlet 30 and the inert gas inlet are formed, for example, separately from each other or as a common inlet to the calciner 14 or the furnace 16. The inert gas is, for example, CO2 or water vapor. The inert gas can be used both as a carrier and to affect ignition or control of the combustion process.

[0067] A cooler 18 for cooling the 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 cooling gas flow. The clinker is transported through the cooling gas chamber 34 in a conveying direction F. The cooling gas chamber 34 has, for example, a first cooling gas chamber part 36 and a second cooling gas chamber part 38 adjacent to the first cooling gas chamber part 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.

[0068] The first cooling gas chamber part 36 is arranged below the material outlet of the furnace 16 so that the clinker falls from the furnace 16 into the first cooling gas chamber part 36. The first cooling gas chamber part 36 represents the intake area of ​​the cooler 18 and preferably has a stationary grate which receives the clinker leaving the furnace 16. The stationary grate is in particular arranged completely in the first cooling gas chamber part 36 of the cooler 10. The clinker preferably falls from the furnace 16 directly onto the stationary grate. The stationary grate preferably extends completely at an angle of 10° to 35°, preferably 14° to 33°, in particular 21° to 25° to the horizontal so that the clinker slides along the stationary grate 40 in the conveying direction.

[0069] 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 cooled, in particular to a temperature below 1000° C., the cooling being performed such that complete solidification of the liquid phase present in the clinker into a solid phase occurs. On leaving the first cooling gas chamber section 36 of the cooler 18, the clinker is preferably provided completely in the solid phase and at a temperature of up to 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 stream can preferably be divided into a plurality of partial gas streams having different temperatures.

[0070] The stationary grate of the first cooling gas chamber part 36 has passages through which the cooling gas enters, for example, the cooler 18 and the clinker. The cooling gas is generated, for example, by at least one fan, blower or pressurized vessel arranged under the stationary grate, so that a first cooling gas flow flows from below through the stationary grate into the first cooling gas chamber part 36. The first cooling gas flow is, for example, pure oxygen or a gas with a nitrogen proportion of 15% by volume or less and an oxygen proportion of 30% by volume or more. The first cooling gas flow flows through the clinker and subsequently enters the furnace 16. The first cooling gas flow forms, for example, partially or completely, the combustion gas of the furnace 16. The high proportion of oxygen in the combustion gas results in a preheater exhaust gas consisting essentially of CO2 and water vapor, which has the advantage that complex downstream cleaning methods for exhaust gas cleaning can be omitted. Furthermore, a reduction in the process gas amount is achieved, which allows the dimensions of the installation to be significantly reduced.

[0071] Inside the cooler 18 the clinker to be cooled is moved in a conveying direction F. The second cooling gas chamber part 38 preferably has a dynamic, in particular a movable, grate adjacent to a stationary grate in the conveying direction F. For example, a number of fans are arranged below the dynamic grate, by means of which a second cooling gas flow is blown out from below at a dynamic speed. The second cooling gas flow is, for example, air.

[0072] 1, for example, the crushing unit 48 is adjacent to the dynamic grate of the second cooling gas chamber section 38. A further dynamic grate is adjacent and below the crushing unit 48. The cold clinker preferably has a temperature of 100° C. or less when it leaves the cooler 18.

[0073] The cooler exhaust air is discharged, for example, from the second cooling gas chamber section 38 and directed into a separator, for example a cyclone, for separating the solids. The solids are returned, for example, to the cooler 18. An air-to-air heat exchanger is connected downstream of the separator, whereby the cooler exhaust air preheats air in the heat exchanger that is fed, for example, to the raw material mill.

[0074] 3 shows a further exemplary embodiment of an installation 14 for heat treatment, in particular a calciner, which at least partially corresponds to the installation 14 of FIG. 1, with identical reference numerals representing identical elements. For example, two fuel distributors 64, 66 are attached to the riser line 62, through each of which the fuel and the inert gas are distributed together.

[0075] The riser line 62 of the facility 14 has a number of different cross-sectional areas. The fuel distributors 64, 66 of the facility 14 are mounted on the same side of the riser line 62 at different elevation levels, for example without any angular offset. In the gas flow direction in the riser line 62, the raw meal inlets 44, 46 are preferably directly connected upstream and / or downstream of each fuel distributor, respectively. The fuel inlets 48, 50 and the inert gas inlets 52, 54 are each arranged in the fuel distributors 64, 66 of the calciner 14, in particular at the same elevation as the respective fuel distributors.

[0076] The cross-sectional constriction ensures balanced mixing in the riser line and thus homogenization of the combustion and the temperature distribution longitudinally and transversely in the riser line of the calciner.

[0077] Figure 4 shows a detail of the installation 14 according to Figures 1 to 3, in particular the calciner 14, where identical references represent identical elements. The installation 14 has a guide element 73 which in the left-hand illustration is attached, for example, to the inside of the riser line 62 and in the right-hand illustration is attached, for example, to a fuel distributor with a special form of flame tube.

[0078] In the left-hand illustration, the guide element 73 is arranged so as to cause a narrowing of the cross section of the riser line 62. The guide element 73 is in particular made in the shape of a plate, a chamber or a box and is attached to the inner wall of the riser line 62, for example at the same height as the fuel distributor 66 and opposite it.

[0079] In the right-hand illustration, the guide element 73 has, for example, the form of a diffuser, the cross section of which increases in the direction of fuel flow. The guide element 73 is mounted in the fuel distribution device, in particular in the riser line 62 at the orifice of the fuel distribution device, and in particular allows a targeted introduction of the fuel into the riser line 62. It is also conceivable that the guide element 73 ends flush with the riser line and does not protrude into it, allowing a uniform introduction of the fuel into the riser line 62.

[0080] The guide element 73 is made, for example, from a high-temperature resistant ceramic or fiber composite material. [Explanation of symbols]

[0081] 10. Cement manufacturing plant 12 Preheater 14 Heat treatment equipment / calciners 16 Furnace 18 Cooler 20. Cyclone 22 Preheater exhaust gas 28 Furnace burners or burner lances 30 Furnace fuel inlet 32 First Processing Area 33 Second Processing Area 34 Cooling gas chamber 36 First cooling gas chamber section 38 Second cooling gas chamber 40 Cross-sectional constriction 42 Cross-sectional constriction 44 First raw meal inlet 46 Second raw meal inlet 48 First fuel inlet 50 Second fuel inlet 52 First inert gas inlet 54 Second inert gas inlet 56 Temperature measuring unit 58 Temperature measuring unit 60 Adjustment Unit 62 Ascending Pipe Line 64 Fuel distribution device 66 Fuel distribution device 73 Guidance elements

Claims

1. 1. An installation (14) for heat treatment of buoyant material, comprising: a riser line (62) through which hot gas can flow; the riser line having at least one fuel inlet (48, 50) for introducing fuel into the riser line (62); the riser line (62) has at least one raw meal inlet (44, 46) for introducing raw meal into the riser line (62), the at least one raw meal inlet being arranged inside the riser line (62) in a flow direction of the hot gases upstream of the fuel inlet (24); 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).

2. The riser line has at least two treatment zones (32, 33) arranged successively in the flow direction of the hot gas and having different diameters from each other, 2. The installation (14) of claim 1, wherein a front processing area (32) in the flow direction of the hot gases has a raw meal inlet (44) for introducing raw meal into the front processing area (32).

3. 3. The installation (14) according to claim 2, wherein the riser line (62) has at least one cross-sectional constriction (40, 42) between the treatment areas (32, 33) having a smaller diameter than the treatment areas (32, 33).

4. The installation (14) of claim 2 or claim 3, wherein the fuel inlet (48, 50) is located downstream of the front treatment area (32).

5. 5. The installation (14) of claim 4, wherein the riser line (62) has a further cross-sectional narrowing (40) upstream of the front treatment area (32).

6. the riser line (62) having at least two raw meal inlets (44, 46) for introducing raw meal into the riser line (62); 6. The installation (14) according to any of claims 2 to 5, wherein the raw meal inlets (44, 46) are respectively arranged in different treatment zones (32, 33) of the riser line (62).

7. At least one of the fuel inlets (48, 50) has at least one or more fuel lines extending radially from the riser line; the at least one or more fuel lines extend into the riser line (62) through a wall of the riser line; At least one of the raw meal inlets (44, 46) has at least one or more raw meal lines extending in the radial direction of the riser line; 7. The installation (14) of any one of claims 1 to 6, wherein the at least one or more raw meal lines extend into the riser line through a wall of the riser line.

8. The installation (14) of claim 7, wherein the fuel line extends into the riser line at an angle of between 0° and ±50° relative to the raw meal line.

9. At least one temperature measuring unit (56, 58) is arranged in the riser line (62) for ascertaining the temperature inside the riser line (62); The installation (14) has a conditioning unit (60) connected to the temperature measuring units (56, 58) for transmitting the ascertained temperature, 9. The installation (14) according to any one of claims 1 to 8, wherein the adjustment unit (60) is designed to adjust the amount of raw meal, inert gas and / or fuel into the riser line depending on the ascertained temperature.

10. 10. The installation (14) according to any one of claims 1 to 9, wherein the installation (14) is an installation for the thermal treatment of cement raw meal and / or mineral products.

11. The installation (14) of claim 7 or claim 8, wherein the fuel line extends into the riser line at an angle of between ±0° and ±30° to the raw meal line.

12. 1. A method for heat treating a buoyant feedstock, comprising the steps of: introducing fuel via a fuel inlet (48, 50) into a riser line (62) for conducting hot gas; introducing raw meal into said riser line (62); Including, the raw meal is introduced into the riser line (62) upstream of the fuel inlet (48, 50) in a flow direction of the hot gas, and an inert gas is introduced into the riser line (62).

13. the riser line (62) has at least two treatment zones (32, 33) arranged successively in the flow direction of the hot gas and having different diameters from each other, The method of claim 12, wherein the raw meal is introduced into a front processing area (32) in the flow direction of the hot gas.

14. 14. The method according to claim 12 or 13, wherein a temperature is ascertained by at least one temperature measuring unit (56, 58) inside the riser line (62) and the amount of raw meal, inert gas and / or fuel in the riser line is adjusted depending on the ascertained temperature.

15. Fuel is introduced into the riser line (62) through at least two fuel inlets (48, 50) arranged in series in the flow direction of the hot gas; A method according to any of claims 12 to 14, wherein more fuel is introduced at a front fuel inlet (48, 50) in the flow direction than at the other fuel inlets (48, 50).

16. 14. The method of claim 13, wherein the raw meal is introduced into the front processing zone (32) in an amount equivalent to 20% to 60% of the total amount of the raw meal introduced into the riser line (62).

17. 17. A method according to any of claims 12 to 16, wherein the method is a method for thermally treating cement raw meal and / or mineral products.

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