VERTICAL SHAFT KINDER

Abstract

A vertical shaft furnace is provided for heating and cooling a continuously or quasi-continuously flowing bulk material moving bed. Furthermore, a plant for the calcination, sintering and / or production of soft-burned lime, medium-burned lime and hard-burned lime, wollastonite, cement clinker using carbonate-containing and / or mineral bulk materials, ores and / or other bulk materials will be provided. Furthermore, a system is provided which includes vertical shaft furnaces according to the invention that are operated in parallel.

Description

Technical field

[0001] The present invention relates to a vertical shaft kiln for heating and cooling a continuously or quasi-continuously flowing bulk material moving bed, a plant for the calcination, sintering and / or production of soft-burned lime, medium-burned lime and hard-burned lime, wollastonite, cement clinker using carbonate-containing and / or mineral bulk materials, ores and / or other bulk materials, and a system comprising parallel-operated vertical shaft kilns according to the invention. Background of the invention

[0002] Carbonate-containing materials, such as limestone or dolomite, change their chemical composition and crystalline structure when heated. At temperatures between approximately 700 °C and 1,200 °C, limestone (CaCO3) decomposes into carbon dioxide (CO2) and calcium oxide (CaO, quicklime); this process is called lime burning or calcination. For dolomite, the process begins at around 450 °C.

[0003] For every ton of pure lime (CaO), approximately 786 kg of CO2 are inevitably and irreducibly produced, released from the mineral CaCO3. This amount cannot be reduced due to the chemical composition of CaCO3. Furthermore, CO2 is also produced during process heat generation through the combustion of carbon-containing fuels. In total, approximately 1.2 tons of CO2 are generated and emitted for every ton of lime produced.

[0004] In conventional lime kilns, lime is burned using hot combustion gases. By adding extra air to the stoichiometric air requirement of combustion, the temperature of the combustion gases is adjusted to the level required for the desired lime quality. The exhaust gases from lime kilns consist mainly of nitrogen, carbon dioxide from combustion, carbon dioxide from calcination, oxygen, water vapor, and dust. The production of 6.6 million tons of lime and dolomite per year (Germany 2011) thus results in approximately 7.9 million tons of CO2 emissions per year. It would be beneficial to capture the released carbon dioxide at the source and to avoid the CO2 produced during combustion as much as possible. However, separating the carbon dioxide from this gas-dust mixture for the purpose of carbon capture utilization (CCU) or carbon capture storage (CCS) is technically extremely complex and therefore uneconomical.

[0005] Carbonate rocks such as limestone and dolomite, which also include chalk, are used in numerous industries. A large proportion is used for the production of cement in the construction and building materials industry.

[0006] Furthermore, they are used in the production of iron, steel, glass and paper, mortars and plasters, in agricultural and forestry fertilization, water treatment, as animal feed, as fillers in plastics, adhesives, paints, varnishes or ceramic compounds, in the chemical industry and in the production of food and beverages. In Germany, approximately 55.2 million tons of limestone, dolomite and marlstone, including chalk, were extracted in 2020 that were not used as crushed natural stone (see Germany - Raw Materials Situation 2020, Federal Institute for Geosciences and Natural Resources).

[0007] Depending on its intended use, quicklime is subject to different requirements, the limits of which are constantly being narrowed by increasingly precise process controls. However, these precise requirements apply to a product whose properties, due to its natural origin, will always be subject to certain fluctuations shaped by the geological history of its raw material, limestone. Producing quicklime precisely to meet specific requirements, despite these natural variations in the raw material, necessitates a thorough understanding of the influencing parameters that affect the resulting quicklime properties.

[0008] Quicklime is produced by thermal dissociation of limestone (so-called calcination) with the release of carbon dioxide: CaCO3 + 178.4 kJ → CaO + CO2 (1)

[0009] If the quicklime produced after calcination is subjected to further temperature exposure, sintering processes occur, which can significantly alter the product's physical properties, such as specific surface area, bulk density, etc. The extent of these changes can vary considerably depending on the type of limestone. These sintering processes directly influence quicklime reactivity, one of the most important parameters for process control in applications where quicklime is used. Quicklime reactivity is a product parameter that relates to the reaction rate of quicklime with water. The enthalpy of the reaction CaO + H2O → Ca(OH)2 +65.19 kJ (2) While the heat capacity (ΔHR) is constant at -65.19 kJ / mol CaO, the reaction rate, and thus the rate of heat release, varies depending on the physical and chemical properties of the quicklime. Based on the reaction rate, which is directly dependent on the degree of sintering, quicklime is classified as hard-burned, medium-burned, or soft-burned. However, there is no precise definition to distinguish between these groups. As a guideline, a maximum reaction time of two minutes can be assumed for soft-burned quicklime, while a reaction time between two and eight minutes characterizes medium-burned quicklime, and hard-burned quicklime requires an even longer period until all the CaO content is converted to Ca(OH)₂.

[0010] From DE 10 2021 202 485 A1, a shaft furnace for burning, in particular, carbonate-containing material is known, which has a preheating zone for preheating the material, a combustion zone for burning the material, a cooling zone for cooling the burned material, and a material outlet for discharging the material from the shaft furnace, wherein the shaft furnace has a recirculation device for circulating recirculation gas within the combustion zone and for generating a co-current combustion zone within the combustion zone.

[0011] WO 2011 / 138022 further describes a process for converting carbonates into oxides with the release of carbon dioxide in calcining furnaces in which carbon-containing fuels are burned, whereby mineral feedstocks are thermally treated. The process is characterized in that technical oxygen or air enriched with technical oxygen is used as an oxidizing agent in the fuel mixture and the CO2-containing exhaust gas produced during combustion is at least partially introduced as a cooling gas into a cooling zone at the lower end of the calcining furnace.

[0012] The method described in WO 2011 / 138022 attempts to minimize the high throughput through the entire bed by burning oxygen. However, in this case, cooling or preheating is always dependent on combustion in the heating zone. Object of the invention

[0013] It is therefore the object of the present invention to provide a device for calcining, sintering and / or producing soft-burned lime, medium-burned lime and hard-burned lime, wollastonite, cement clinker using carbonate-containing and / or mineral bulk materials, ores and / or other bulk materials, which enables the most energy-efficient production possible of specific, fired end products.

[0014] This task is solved using the independent claims. The dependent claims further develop the core idea of ​​the invention. Summary of the invention

[0015] In a first aspect of the invention, a vertical shaft furnace is provided for heating and cooling a continuously or quasi-continuously flowing bulk material moving bed.

[0016] An oven is understood to be a component that, with the addition of heat to the bulk material, allows the thermal modification of physical material properties such as particle size, density, porosity and / or crystal structure, etc., but also chemical reactions of the bulk material.

[0017] The vertical shaft furnace comprises a substantially vertically arranged shaft, which has an upper bulk material inlet and a lower bulk material outlet, and in at least one shaft area between the upper bulk material inlet and the lower bulk material outlet has passage openings in horizontally opposing shaft walls for a heat transfer medium flowing at least partially transversely to the direction of flow of the bulk material, and the passage openings have at least one guiding element around which the heat transfer medium flows, directing the bulk material towards the bulk material outlet.

[0018] The guide elements can be arranged horizontally opposite each other and / or horizontally offset.

[0019] The heat transfer medium can flow partially or completely around the guide element. In one embodiment, the flow around the guide element can occur only from one side, e.g., the top, and not from the other side, e.g., the bottom. In another embodiment, the heat transfer medium flows around the guide element from both the top and the bottom.

[0020] The opposing arrangements can be in a rectangular and / or round oven and arranged opposite each other but vertically offset.

[0021] The heat transfer medium can be, for example, nitrogen, carbon dioxide, water vapor and / or air, but also mixtures of gases or multiphase media, such as a gas / particle flow or a gas / droplet flow.

[0022] A bulk material moving bed is understood to be a bulk material that moves in a vertical direction.

[0023] In the present invention, the term "bulk material" refers to fine-grained or lumpy material. The bulk material can, for example, comprise or consist of mineral-containing, in particular carbonate-containing, bulk material. The material can be granular materials, raw granules, pellets, briquettes, or similar compacts or agglomerates. The range of usable particle size distribution is preferably between 50 µm and 150 mm.

[0024] Mineral-containing, especially carbonate-containing, bulk material includes limestone, quicklime and / or compacted cement raw material.

[0025] In addition to CaO and CaCO3, already burnt lime, raw cement compact (raw) or raw cement compact (pre-calcined) can pass through the vertical shaft kiln.

[0026] The use of agglomerated raw materials allows the production of cement and hydraulic lime, as well as other products based on carbonate-containing raw materials.

[0027] Agglomeration is a collective term for processes that increase the size of particles by joining them together. Agglomeration is primarily used with fine-grained or powdered raw materials to improve flowability and thus machinability. Very fine-grained powders often have an extremely low bulk density, are easily agitated, and tend to adhere to surfaces.

[0028] Agglomerated powder particles are much easier to handle and process. Mixing the raw materials allows for very precise control of the chemical composition of the agglomerates. Due to the predetermined mixture and the contact surfaces and points between the individual components created or enforced by agglomeration, mineral formation is enabled without the need to partially or completely melt the mixture, as is the case in rotary kilns during cement production.

[0029] The advantage is that the energy-intensive melting of the mixture, and thus the energy-efficient mineral formation, is avoided when using raw materials. Agglomeration preferably occurs through pelletizing or briquetting.

[0030] It is advantageous to use starting materials with water contents of up to 20 wt.% for the agglomerates in order to minimize spalling of the agglomerate at temperatures above 100 °C due to water evaporation.

[0031] Furthermore, the supplied raw material can consist predominantly of soft-burned lime, and a medium-burned or hard-burned product can be produced by a predetermined residence time and temperature in the middle range.

[0032] The supplied raw material can also consist of dolomite or limestone flour (<300 µm), which, through agglomeration, achieves grain sizes greater than 300 µm, but especially greater than 1 mm, and, through a predetermined residence time and temperature in the middle range, produces burnt lime, burnt dolomite or semi-burnt dolomite.

[0033] Alternatively, the supplied raw material can consist of cement raw materials and be processed into cement clinker by a predetermined residence time and temperature in the medium range.

[0034] This also allows the production of cement clinker and / or heat-treated sintered material with specified mechanical or chemical properties.

[0035] The bulk material may also comprise particles and / or agglomerates, wherein the agglomerates are formed as pellets and / or briquettes and the edge lengths or diameters of the particles and / or agglomerates are preferably in the range of 0.1 mm to 150 mm.

[0036] The bulk material may also consist of agglomerated raw materials comprising one or more of the substances silicon dioxide, aluminium oxide, an iron compound, in particular iron(III) oxide, as well as calcium carbonate and / or calcium oxide.

[0037] The bulk material preferably has a water content of up to 20 wt.%.

[0038] The vertical shaft furnace is made of a high-temperature material such as refractory concrete, refractory bricks, silicon carbide or austenitic stainless steels.

[0039] In a preferred embodiment of the device according to the first aspect, it is characterized in that the vertical shaft furnace comprises opposing arrangements of at least two guide elements arranged in a blind-like manner at predetermined vertical distances at a predetermined horizontal distance.

[0040] In a further preferred embodiment of the device according to the first aspect, it is characterized in that the guide elements are positioned at an angle between 0 and 90 degrees to the horizontal in the direction of the bulk material outlet.

[0041] The guiding elements according to the invention therefore allow the heat transfer medium to flow through the bulk material at least partially transversely and, due to the blind-like arrangement, uniformly.

[0042] In a further preferred embodiment of the device according to the first aspect, it is characterized in that the magnitude of the angle of inclination of the guide elements corresponds to the magnitude of the angle of repose of the bulk material.

[0043] In a further preferred embodiment of the device according to the first aspect, it is characterized in that the vertical shaft furnace comprises at least one funnel-shaped guide element, preferably at least two funnel-shaped guide elements arranged at predetermined vertical distances.

[0044] In a further preferred embodiment of the device according to the first aspect, it is characterized in that the shaft, apart from the at least one guiding element, has no internal components influencing the flow of the heat transfer medium.

[0045] In a further preferred embodiment of the device according to the first aspect, it is characterized in that the bulk material inlet and the bulk material outlet are arranged vertically one above the other and have the same shaft cross-section.

[0046] In a further preferred embodiment of the device according to the first aspect, it is characterized in that the at least one guide element is arranged outside this shaft cross-section, adjacent to the shaft cross-section.

[0047] In a further preferred embodiment of the device according to the first aspect, it is characterized in that the vertical shaft furnace has an upper shaft area between the upper bulk material inlet and the lower bulk material outlet, which forms a preheating zone for preheating the bulk material, a middle shaft area, which forms a heating zone for heating the bulk material to a predetermined target temperature, and a lower shaft area, which forms a cooling zone for cooling the bulk material.

[0048] At least the upper shaft area and the lower shaft area have at least one guiding element around which the heat transfer medium flows.

[0049] The guiding elements according to the invention thus enable a spatial and therefore fluid-technical separation of the heating / preheating and cooling areas from the central heating area, the so-called heating zone.

[0050] The throughput through these areas can therefore also be individually controlled and is also very flexible with regard to cooling and preheating in terms of the type of heat transfer medium.

[0051] In a further preferred embodiment of the device according to the first aspect, it is characterized in that the central shaft area has no opposing guide elements.

[0052] In a further preferred embodiment of the device according to the first aspect, it is characterized in that the central shaft area also has at least one guiding element around which the heat transfer medium flows.

[0053] Preferably, one or more predetermined temperature ranges between 380 °C and 1200 °C can be set in the vertical shaft furnace for calcination.

[0054] Preferably, one or more predetermined temperature ranges between 400°C and 1600°C can be set, particularly for sintering.

[0055] In the direction of flow of the bulk material upstream of the heating zone, the upper shaft section, the so-called preheating zone, is arranged for preheating the bulk material. The preheating zone preferably connects directly to a material inlet for the bulk material into the vertical shaft furnace and serves to preheat the bulk material to a temperature of approximately 600 °C to 800 °C.

[0056] The central shaft area, the heating zone, preferably connects directly to the preheating zone and serves to burn the bulk material, which is preferably heated to a temperature of about 900 °C to 1400 °C.

[0057] The lower shaft section, the cooling zone, preferably connects directly to the heating zone and serves to cool the fired bulk material to a temperature of, for example, 100 °C. The material outlet is located, for example, in an outlet hopper adjoining the cooling zone.

[0058] This advantageous design also allows the starting materials to be first calcined and then sintered.

[0059] In a further preferred embodiment of the device according to the first aspect, it is characterized by a supply line connected to the passage openings of at least one shaft area and a discharge line connected to the correspondingly opposite passage openings.

[0060] In a further preferred embodiment of the device according to the first aspect, it is characterized in that each shaft area has its own supply line and its own discharge line.

[0061] Depending on the kiln type, conventional lime kilns are primarily suited for producing either soft-burned lime (GGR, ring shaft kilns) or hard-burned lime (shaft kiln). Medium-burned lime is produced as a compromise between soft- and hard-burned lime in subsequent, complex process steps. For example, homogeneous temperature profiles cannot be achieved in shaft kilns, which can lead to chemically contaminated lump lime forming sinter deposits with other lump lime, potentially causing production interruptions.

[0062] According to the invention, soft-burned, medium-burned, or hard-burned lime can be selectively controlled by adjusting the temperatures and residence time in the heating zone. This means that quicklime with defined product qualities (defined residual CO2 contents, defined t60 values, the time required to reach a temperature of 60°C when slaking CaO under defined conditions, i.e., soft-burned, medium-burned, or hard-burned) can be produced with production capacities of, for example, 200,000 tons per year.

[0063] By using predetermined temperatures and residence times, limestone or dolomite can be produced as differently fired end products, such as soft-, medium-, and hard-fired.

[0064] The placement of the guide elements in the vertical shaft furnace according to the invention allows homogeneous reaction conditions (e.g. of temperature) and high heat transfer due to the at least partially occurring transverse flow of the heat transfer medium.

[0065] This means that precise operating conditions can be set in the vertical shaft kiln according to the invention. Therefore, with the invention presented here, it is possible to precisely produce, for example, the corresponding lime qualities of a soft-burned, medium-burned, and hard-burned lime.

[0066] The residence time of limestone or lime particles in kilns increases with the particle diameter. Fine-grained particles can be calcined with significantly shorter residence times than lump lime.

[0067] In a further preferred embodiment of the device according to the first aspect, it is characterized in that a common first inlet and a common first outlet are assigned to the upper and lower shaft areas, while a second inlet and a second outlet are assigned to the middle shaft area.

[0068] The advantage lies in the fact that the middle section of the vertical shaft furnace forms a closed or nearly closed system to achieve an adjustable target temperature, and a second heat transfer medium flows continuously or quasi-continuously largely across the bulk material, heating the bulk material and / or the heat transfer medium in the middle section of the vertical shaft furnace, the so-called heating zone, while independently of this, the bulk material within the upper and lower sections is permeated by another first heat transfer medium.

[0069] In a further preferred embodiment of the device according to the first aspect, it is characterized in that a heater is assigned to the upper shaft area and / or the middle shaft area.

[0070] The almost closed guide in the heating area also allows for low gas or heat transfer medium flow and optimal heat utilization.

[0071] In a further preferred embodiment of the device according to the first aspect, it is characterized by an electric, inductive or fuel combustion-based heating system.

[0072] Electric heating and separate cooling / preheating with a gas flow or a heat transfer medium flow are also possible.

[0073] In a further preferred embodiment of the device according to the first aspect, it is characterized in that at least one further supply line, preferably a gas supply line, is assigned to the lower shaft area of ​​the vertical shaft furnace.

[0074] Quicklime is used in DAC (Direct Air Capture) to remove carbon dioxide from the air or exhaust gases.

[0075] This has the advantage that if the goal is CO2 separation from air (DAC) or flue gases (CO2 separation), the vertical shaft kiln according to the invention can be used for a process to bind CO2 to the lime.

[0076] This is done via the known mechanisms. CaO + H2O + CO2 → Ca(OH)2 + CO2 → CaCO3 + H2O (3) or CaO + CO2 → CaCO3 (4)

[0077] If CO2 is to be separated from the air, in this aspect a gas is introduced into the lower area of ​​the vertical shaft furnace via the additional line, then preheated and finally CO2 is bound to CaO according to one of the aforementioned mechanisms.

[0078] In the case of flue gas, depending on the temperature of the flue gas, a corresponding temperature level would be selected in the shaft furnace into which the flue gas is added.

[0079] In a further preferred embodiment of the device according to the first aspect, it is characterized by a pressure measuring device with pressure sensors assigned to the bulk material inlet, the bulk material outlet and the passage openings for measuring the gas pressures at the bulk material inlet, at the bulk material outlet and at the passage openings.

[0080] In a further preferred embodiment of the device according to the first aspect, it is characterized by a differential pressure control for controlling the differential pressures between the passage openings and / or between the bulk material inlet and the bulk material outlet and / or between one of the passage openings and the bulk material outlet or the bulk material inlet.

[0081] In a further preferred embodiment of the device according to the first aspect, it is characterized in that the differential pressure control comprises controllable flaps and / or valves in a supply line leading to one of the through-openings and / or in a discharge line leading from a correspondingly opposite through-opening.

[0082] In a further preferred embodiment of the device according to the first aspect, it is characterized in that the differential pressure control comprises several controllable vacuum sources.

[0083] In a second aspect of the invention, a plant for the calcination, sintering and / or production of soft-burned lime, medium-burned lime and hard-burned lime, wollastonite, cement clinker is provided using carbonate-containing and / or mineral bulk materials, ores and / or other bulk materials, comprising a vertical shaft kiln according to the invention and a heat recovery device.

[0084] The heat recovery system is used to utilize the heat contained in the hot combustion gases, the hot gases from the vertical shaft furnace and / or the hot intermediate and end products from the vertical shaft furnace for preheating the bulk material and / or a heat transfer medium.

[0085] In a second preferred embodiment of the device according to the second aspect, it is characterized in that the heat recovery device comprises a condenser for condensing water vapor contained in the hot gas from the vertical shaft furnace and for materially separating carbon dioxide from the hot gases.

[0086] The water obtained during condensation can in turn be used to generate steam.

[0087] In a third aspect of the invention, a system comprising parallel-operated vertical shaft furnaces according to the invention is provided, wherein the upper, middle and lower shaft areas of the respective vertical shaft furnaces are connected to each other via their own supply line and their own discharge line. Other possible embodiments

[0088] According to another aspect of the invention, the individual areas - preheater - heating zone - cooling zone - are each designed as a separate reactor stacked on top of each other, whereby the sealing against gas leakage at the inlet and / or outlet is ensured by means of technical shut-off devices such as rotary valves and / or by a bulk material height adapted to the respective physical conditions of the gas crossflow.

[0089] According to another aspect of the invention, the gaseous heat transfer medium is generated by a turbomachine.

[0090] According to another aspect of the invention, at least one of the shaft areas is assigned a piston displacement device which alternately supplies and directs a heat transfer medium to the passage openings of each of the horizontally opposing guide element arrangements.

[0091] This causes the heat transfer medium flow to change direction.

[0092] According to another aspect of the invention, reaction gases, for example water vapor, are introduced into the lower part of the kiln. This leads to the hydration of the lime.

[0093] According to another aspect of the invention, the guide elements are sufficiently long to prevent the bulk material from overflowing. The guide element angle can be set between 0 degrees (horizontal) and 90 degrees (vertical) depending on parameters such as the pressure drop, the angle of repose, and the volumetric flow rate. The guide element length can also be adjusted depending on the guide element angle and the angle of repose.

[0094] Balancing energy in the public electricity grid, also known as control reserve, compensates for fluctuations in the grid, specifically in the grid frequency. When balancing energy is deployed, electricity can both be drawn from and fed into the grid. Increasing the feed-in to compensate for a low grid frequency is called positive balancing energy, while reducing the feed-in to lower the grid frequency is called negative balancing energy. Participants in the balancing energy market must maintain the agreed-upon balancing energy reserves. Compensation is paid for the availability of balancing energy and, if it is used, for its actual deployment. Industrial processes that meet the criteria for participation in the balancing energy market have an economic advantage.Due to the use of electricity for process heat generation and the possibility of using fuels additionally or exclusively for process heat generation, the vertical shaft furnace according to the invention is suitable for participating in the balancing energy market.

[0095] Solid, gaseous, liquid fuels and / or electricity can be used to generate process heat.

[0096] The nitrogen oxides (NOx) and volatile hydrocarbons produced during conventional combustion processes are completely avoided when electricity is used for process heat generation.

[0097] If electricity replaces fuel, then no exhaust gas is emitted from the plant for that amount of energy. If the electricity is based on renewable energies, the CO2 footprint decreases accordingly, meaning the proportion of the substituted fuel drops to zero.

[0098] Furthermore, indirect heat transfer, for example by means of internal components such as heat pipes, can prevent contact between fuel, exhaust gas and the product, so that the product is not contaminated.

[0099] In another aspect, the lower shaft area can also be assigned a supply line, which is connected to an outlet of the lower shaft area with a supply line of the middle shaft area, an outlet of the middle shaft area with a supply line of the upper shaft area, and an outlet is assigned to the upper shaft area.

[0100] In a further aspect of the present invention, a first supply line can be assigned to the lower shaft area, an outlet of the lower shaft area can be connected to a supply line of the upper shaft area, and a first outlet can be assigned to the upper shaft area, and a second supply line and a second outlet can be assigned to the middle shaft area.

[0101] This ensures that a first heat transfer medium is initially assigned to the lower shaft area of ​​the vertical shaft furnace and subsequently to the upper shaft area of ​​the vertical shaft furnace, while an independent second heat transfer medium is assigned to the middle shaft area via its own supply and discharge lines.

[0102] This has the advantage that the heat absorbed by the bulk material in the lower shaft area can be at least partially transferred to the bulk material in the upper shaft area.

[0103] In another aspect of the invention, gas exchange is also possible through the flowing heat transfer medium. In this process, gases present in the bulk material are flushed out by the heat transfer medium. List of characters

[0104] These and other features, aspects, and benefits of the present revelation will be better understood when the following detailed description is read with reference to the accompanying figures, wherein: Fig. 1 shows a schematic representation of a vertical shaft furnace (1) in accordance with an embodiment of the present disclosure; Fig. 2 shows a schematic representation of a vertical shaft furnace (1) in accordance with an embodiment of the present disclosure; Fig. 3 shows a schematic representation of a vertical shaft furnace (1) in accordance with an embodiment of the present disclosure; Fig. 4 shows a schematic representation of a vertical shaft furnace (1) in accordance with an embodiment of the present disclosure; Fig. 5 shows a schematic representation of a vertical shaft furnace (1) in accordance with an embodiment of the present disclosure; Fig. 6 shows a schematic representation of a vertical shaft furnace (1) in accordance with an embodiment of the present disclosure; Fig. 7 shows a schematic representation of a vertical shaft furnace (1) in accordance with an embodiment of the present disclosure; Fig. 8 shows a schematic representation of a system of parallel operated vertical shaft furnaces (1) in accordance with an embodiment of the present disclosure; Fig. Figure 9 shows a schematic representation of a vertical shaft furnace (1) in accordance with an embodiment of the present disclosure. Fig. Figure 10 shows a schematic representation of a vertical shaft furnace (1) in accordance with an embodiment of the present disclosure. Fig. Figure 11 shows a schematic representation of a vertical shaft furnace (1) in accordance with an embodiment of the present disclosure. Fig. Figure 12 A shows a schematic representation of an inclined guide element of the vertical shaft furnace (1) in accordance with an embodiment of the present disclosure. Fig. 12 B a schematic representation of a less steeply angled guide element of the vertical shaft furnace (1) compared to Fig. 12 A in accordance with an embodiment of the present disclosure. Detailed description

[0105] The exemplary embodiment according to Fig. Figure 1A shows a vertical shaft kiln (1) which, in the direction of flow of the bulk material, comprises an upper bulk material inlet (2), an upper shaft area (4), the preheating zone, for preheating the bulk material, a middle shaft area (5), the heating zone, for firing the bulk material, a lower shaft area (6), the cooling zone, for cooling the fired material, and a lower bulk material outlet (3) for discharging the bulk material from the vertical shaft kiln (1), wherein in this exemplary embodiment the inventive louver-like guide elements (8) are arranged uniformly over the entire vertical height of the vertical shaft kiln (1) and the heat transfer medium flows through the areas at least partially transversely to its flow direction.

[0106] In Fig. In addition, each shaft area (4, 5, 6) in 1A is assigned its own supply line (10) and its own discharge line (11).

[0107] Fig. 1B shows a sectional view of the Fig. 1A.

[0108] Fig. Figure 2 shows a schematic representation of a further exemplary embodiment of the invention, wherein a common first inlet (12) and a common first outlet (13) are assigned to the upper (4) and lower (6) shaft area, and a second inlet (14) and a second outlet (15) are assigned to the middle shaft area (5).

[0109] Fig. Figure 3A shows a schematic representation of a further exemplary embodiment of the invention, in which a supply line (10) is assigned to the lower shaft area (6), wherein the discharge (11) of the lower shaft area (6) is connected to a supply line (10) of the middle shaft area (5), a discharge (11) of the middle shaft area (5) is connected to a supply line (10) of the upper shaft area (4), and a discharge (11) is assigned to the upper shaft area (4).

[0110] Fig. 3B shows a sectional view of the Fig. 3A.

[0111] Fig. 3C shows a side view of the Fig. 3A

[0112] Fig. 4A shows a schematic representation of a Fig. 3 further exemplary embodiments of the invention.

[0113] Fig. 4B shows a sectional view of the Fig. 4A.

[0114] Fig. 4C shows a side view of the Fig. 4A

[0115] Fig. Figure 5 shows a schematic representation of a further exemplary embodiment of the invention, in which a first inlet (12) is assigned to the lower shaft area (6), a first outlet (13) of the lower shaft area (6) is connected to an inlet (12) of the upper shaft area (4), and a first outlet (13) is assigned to the upper shaft area (4). A second inlet (14) and a second outlet (15) are also assigned to the middle shaft area (5).

[0116] Fig. Figure 6 shows a schematic representation of another exemplary embodiment of the invention, in which the upper shaft area (4) and the lower shaft area (6) have opposing guide element arrangements (8).

[0117] The central shaft section (5) of the vertical shaft furnace (1), the so-called heating zone, is heated directly by electricity in this exemplary embodiment (16). The heat transfer medium is therefore conveyed from the lower shaft section (6) to the upper shaft section (4).

[0118] Fig. Figure 7 shows a schematic representation of another exemplary embodiment of the invention. In this embodiment, at least one of the shaft areas (4, 5, 6) is assigned a piston displacement device which alternately supplies and discharges a heat transfer medium to the through-openings (9) of each of the horizontally opposing guide element arrangements (8). Additionally, heating elements (19) are arranged between the pistons (18) and the guide elements (8).

[0119] Fig. Figure 8 shows a schematic representation of another exemplary embodiment of the invention. The Fig. The system shown in Figure 8 comprises parallel vertical shaft furnaces (1), wherein the upper (4), middle (5) and lower (6) shaft areas of the respective vertical shaft furnaces (1) are each assigned their own supply line (10) and their own discharge line (13).

[0120] Fig. Figure 9 shows a schematic representation of another exemplary embodiment of the invention, in which additional heating elements (19) are attached. In addition, the upper shaft area (4) is connected to the lower shaft area (6) via an additional conduit.

[0121] Fig. Figure 10 shows a schematic representation of a further exemplary embodiment of the invention, in which a first supply line (12) is assigned to the lower shaft area (6), a first outlet (13) of the lower shaft area (6) is connected to a supply line (12) of the upper shaft area (4), and a first outlet (13) is assigned to the upper shaft area (4). A direct or indirect heating system (16) is also assigned to the middle shaft area (5).

[0122] Fig. Figure 11 shows a schematic representation of a further exemplary embodiment of the invention, in which a first supply line (12) and a second supply line (14) are assigned to the lower shaft area (6), a first outlet (13) and a second outlet (15) of the lower shaft area (6) are each connected to a supply line (10) of the upper shaft area (4), and a first outlet (13) and a second outlet (15) are assigned to the upper shaft area (4). Furthermore, a direct or indirect heating system (16) is assigned to the middle shaft area (5).

[0123] Fig. Figure 12A shows a schematic representation of an inclined guide element of the vertical shaft furnace (1) in accordance with an embodiment of the present disclosure, wherein the guide elements are sufficiently long to prevent the bulk material from overflowing.

[0124] Fig. Figure 12B shows a schematic representation of a less steeply angled guide element of the vertical shaft furnace (1) in comparison to Fig. 12 A in accordance with an embodiment of the present disclosure, wherein the guide elements are sufficiently long to prevent the bulk material from overflowing. Reference symbol list: 1 vertical shaft furnace 2 upper bulk material inlet 3 lower bulk material outlet 4 upper shaft area 5 middle shaft area 6 lower shaft area 7 Horizontal spacing of opposing arrangements consisting of at least two guide elements arranged in a blind-like manner at predetermined vertical intervals 8 Conductive element surrounded by the heat transfer medium 9 passage openings 10 Supply line 11 Derivative 12 first supply line 13 first derivative 14 second supply line 15 second derivative 16 Heating 17 additional supply lines 18 pistons 19 heating elements QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2021 202 485 A1

[0010] WO 2011 / 138022 [0011, 0012] Cited non-patent literature

[0000] Millions of tons of limestone and dolomite per year (Germany 2011

[0004]

Claims

[1] Vertical shaft furnace (1) for heating and cooling a continuously or quasi-continuously flowing bulk material moving bed, wherein the vertical shaft furnace (1) comprises a substantially vertically arranged shaft which has an upper bulk material inlet (2) and a lower bulk material outlet (3), the vertical shaft furnace (1) has passage openings (9) in horizontally opposing shaft walls in at least one shaft section (4, 5, 6) between the upper bulk material inlet (2) and the lower bulk material outlet (3) for a heat transfer medium flowing at least partially transversely to the direction of flow of the bulk material, and The passage openings (9) shall have at least one guiding element (8) around which the heat transfer medium flows, directing the bulk material towards the bulk material outlet (3). [2] Vertical shaft furnace (1) according to claim 1, wherein the vertical shaft furnace (1) comprises opposing arrangements of at least two guide elements (8) arranged in a blind-like manner at predetermined horizontal distances (7). [3] Vertical shaft furnace (1) according to claim 2, wherein the guide elements (8) are positioned at an angle between 0 and 90 degrees to the horizontal in the direction of the bulk material outlet (3). [4] Vertical shaft furnace (1) according to claim 3, wherein the magnitude of the angle of inclination of the guide elements (8) corresponds to the magnitude of the angle of repose of the bulk material. [5] Vertical shaft furnace (1) according to claim 1, wherein the vertical shaft furnace (1) comprises at least one funnel-shaped guide element (8), preferably at least two funnel-shaped guide elements (8) arranged at predetermined vertical distances. [6] Vertical shaft furnace (1) according to any one of claims 1 to 5, wherein the shaft, apart from the at least one guide element (8), has no internals influencing the heat transfer medium flow. [7] Vertical shaft furnace (1) according to any one of claims 1 to 6, wherein the bulk material inlet (2) and the bulk material outlet (3) are arranged vertically one above the other and have the same shaft cross-section. [8] Vertical shaft furnace (1) according to claim 7, wherein the at least one guide element (8) is arranged outside this shaft cross-section, adjacent to the shaft cross-section. [9] Vertical shaft furnace (1) according to any one of claims 1 to 8, wherein the vertical shaft furnace (1) has between the upper bulk material inlet (2) and the lower bulk material outlet (3) an upper shaft area (4) which forms a preheating zone for preheating the bulk material, a middle shaft area (5) which forms a heating zone for heating the bulk material to a predetermined target temperature, and a lower shaft area (6) which forms a cooling zone for cooling the bulk material, wherein at least the upper shaft area (4) and the lower shaft area (6) have at least one guiding element (8) around which the heat transfer medium flows. [10] Vertical shaft furnace (1) according to claim 9, wherein the middle shaft area (5) does not have opposing guide elements (8). [11] Vertical shaft furnace (1) according to claim 9, wherein the middle shaft area (5) also has at least one guiding element (8) around which the heat transfer medium flows. [12] Vertical shaft furnace (1) according to any one of claims 1 to 11, characterized by a supply line (10) connected to the passage openings (9) of at least one shaft area (4, 5, 6) and a discharge line (11) connected to the corresponding opposite passage openings (9). [13] Vertical shaft furnace (1) according to claim 12, characterized by , that each shaft area (4, 5, 6) has its own supply line (10) and its own drainage line (11). [14] Vertical shaft furnace (1) according to claim 13, characterized by , that the upper shaft area (4) and the lower shaft area (6) are assigned a common first inlet (12) and a common first outlet (13), and the middle shaft area (5) is assigned a second inlet (14) and a second outlet (15). [15] Vertical shaft furnace (1) according to any one of claims 1 to 14, characterized bya heater (16) assigned to the upper shaft area (4) and / or the middle shaft area (5). [16] Vertical shaft furnace (1) according to claim 15, characterized by an electric, inductive or fuel combustion-based heating system (16). [17] Vertical shaft furnace (1) according to any one of claims 1 to 16, characterized by , that at least one further supply line (17) is assigned to the lower shaft area (6). [18] Vertical shaft furnace (1) according to any one of claims 1 to 17, characterized by a pressure measuring device with pressure sensors assigned to the bulk material inlet (2), the bulk material outlet (3) and the passage openings (9) for measuring the gas pressures at the bulk material inlet (2), at the bulk material outlet (3) and at the passage openings (9). [19] Vertical shaft furnace (1) according to claim 18, characterized bya differential pressure control for controlling the differential pressures between the passage openings (9) and / or between the bulk material inlet (2) and the bulk material outlet (3) and / or between one of the passage openings (9) and the bulk material outlet (3) or the bulk material inlet (2). [20] Vertical shaft furnace (1) according to claim 19, characterized by , that the differential pressure control includes controllable flaps and / or valves in a supply line (10) leading to one of the through-openings (9) and / or in a discharge line (11) leading from a correspondingly opposite through-opening (9). [21] Vertical shaft furnace (1) according to claim 19 or 20, characterized by that the differential pressure control includes several adjustable vacuum sources. [22] Plant for the calcination, sintering and / or production of soft-burned lime, medium-burned lime and hard-burned lime, wollastonite, cement clinker using carbonate-containing and / or mineral bulk materials, ores and / or other bulk materials a vertical shaft furnace (1) according to any one of claims 1 to 21, and a heat recovery device for utilizing the heat contained in the hot combustion gases, the hot gases from the vertical shaft furnace (1) and / or the hot intermediate and end products from the vertical shaft furnace (1) for preheating the bulk material and / or a heat transfer medium. [23] Apparatus for the calcination, sintering and / or production of soft-burned lime, medium-burned lime and hard-burned lime, wollastonite, cement clinker using carbonate-containing and / or mineral bulk materials, ores and / or other bulk materials according to claim 22, characterized by, that the heat recovery device includes a condenser for condensing water vapor contained in the hot gas from the vertical shaft furnace (1) and for materially separating carbon dioxide from the hot gases. [24] System comprising parallel operated vertical shaft furnaces (1) according to any one of claims 1 to 21, wherein the upper (4), middle (5) and lower (6) shaft areas of the respective vertical shaft furnaces (1) are each assigned their own supply line (10) and their own outlet (11).

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