Method and apparatus for conveying hot calcined raw meal

Abstract

The runner 1 for Geldart C group material has a runner plate 10 with a longitudinal axis 2, an upward-facing surface 11 for supporting the Geldart C group material, a lower surface 13, a front side surface 12 and a rear side surface 14. In the case where the runner plate 10 is made of ceramic refractory material, the runner plate 10 can have a significantly reduced slope, wherein the runner plate has a plurality of through holes 20, which provide fluid communication between a fluid inlet 23 in the lower surface 13 and a fluid outlet 21 in the upward-facing surface 11.

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for conveying hot Geldart group C materials. In particular, the present invention relates to a runway plate for a runway for Geldart group C materials, a runway with a runway plate, and a method for conveying hot Geldart group C materials. Background Art

[0002] The conveying of particulate matter is a common problem in many technical fields and many different devices and arrangements have been proposed. In cases where the particulate matter is extremely hot or cold, abrasive, corrosive or for other reasons difficult to handle by mechanical conveying means such as screw conveyors or belt conveyors, a common approach is to fluidize the particulate matter and then slide the fluidized material (air-gravity conveying) or blow the fluidized material (air-jet conveying). Whether fluidization is an option depends on the so-called "Geldart group" associated with the material. As discovered by D. Geldart, particulate materials can be characterized by their ability to be fluidized: "The behavior of solids fluidized by gases falls into four clearly identifiable groups, characterized by density differences (ρ s -ρ f ) and average particle size. The most easily identifiable characteristics of the groups are: powders in group A exhibit dense phase expansion after minimum fluidization and before bubbling begins; those in group B bubble at the minimum fluidization velocity; those in group C are completely difficult to fluidize; and those in group D can form a stable spouted bed. (D. Geldart: Types of Gas Fluidization, Powder Technology, Vol. 7, No. 5, 1973, pp. 285-292).

[0003] An example of a Geldart C Group material is cement clinker raw meal ("raw meal"), an intermediate product of modern cement clinker production lines. The raw meal can be uncalcined, partially calcined, or at least nearly completely calcined. In prior art cement clinker production lines, the hot, calcined raw meal leaves a direct heat exchanger, the so-called calciner, and is transported via the fumes generated in the calciner (fume jet transport) to a cyclone separator. In the cyclone separator, the hot raw meal is separated from the fumes and falls into the raw meal inlet of the kiln. A problem with this process is the carbon dioxide (CO2) emissions from direct heat exchange calciners and kilns: it is estimated that approximately 8% of total anthropogenic CO2 emissions are associated with the cement clinker manufacturing process (Olivier, Janssens-Maenhout, Muntean, and Peters, "Trends in Global CO2 Emissions: 2016 Report," The Hague, PBL Netherlands Environmental Assessment Agency, http: / / edgar.jrc.ec.europa.eu / news_docs / jrc-2016-trends-in-glo-bal-co2-emissions-2016-report-103425.pdf, accessed January 22, 2020, p. 65). As is already apparent, some of the CO2 emissions from the cement clinker process are inherent to the process, as limestone (CaCO3) is calcined to lime (CaO) in the calciner, thereby releasing CO2. The corresponding chemical reaction is described by the formula: CaCO₃ + heat → CaO + CO₂, and is therefore endothermic. This reaction is referred to herein as calcination. Another portion of CO₂ is generated by burning fuel to provide the heat energy to drive the endothermic calcination in the calciner, sintering the lime and other raw meal components into clinker in the kiln, and to generate electricity for operating the plant. Depending on the design and operating parameters of the cement clinker production line, approximately 50-60% of the released CO₂ is released during the calcination step. The remaining approximately 50-40% of CO₂ is released by burning the fuel (see, for example, Johanna Lehne and Felix Preston, "Transforming Concrete Innovations in Low-Carbon Cement and Concrete," Chatham House Report, London, 2018).

[0004] It has been proposed to capture and store the CO2 produced in the clinker manufacturing process. A promising method for capturing CO2 is the so-called regenerative calcium cycle (RCC). RCC essentially consists of capturing CO2 in flue gases by an exothermic reaction of CO2 with CaO to form CaCO3. The reaction is CaO+CO2→CaCO3+heat and is therefore exothermic and is called carbonation. Subsequently, the CaCO3 is decarbonized (i.e. calcined) in a calciner, thereby releasing CO2 and CaO, making it possible to obtain at least substantially pure CO2. The CO2 can be stored, for example, in geological formations (commonly known as CO2 sequestration) or used in other processes. In any case, the CO2 is not released into the environment. The CaO can be subjected to carbonation again.

[0005] As proposed in FR 2921059 A1, RCC can be integrated into the cement clinker process, that is, the calciner for the (pre) calcination of raw meal is the source of CaO required in the carbonation step of RCC. The CaCO obtained in the carbonation step is subsequently provided to the calciner, to obtain fresh CaO, i.e. a part of CaO / CaCO circulates in the process. In this method, the preheated raw meal is provided to the calciner, wherein, in this process, the calciner must be an indirect heat exchanger for heating CaCO . This makes it possible to remove almost pure CO from the calciner. This almost pure CO can be stored or used for other industries or agriculture. The first part of the raw meal that has been calcined is provided to the kiln, to complete the conversion of the raw meal to clinker. The remainder of the raw meal that has been calcined is provided to the carbonator. In the carbonator, the CaO in the raw meal that has been calcined reacts with the CO contained in the flue gas from the kiln to generate CaCO . Therefore, the flue gas experience CO from the kiln is removed. The CaCO3 produced in the carbonator, in which CO2 is bound, is added to the raw meal entering the calciner, where the CO2 is released. Thus, essentially all the CO2 produced in the cement clinker process can be separated and stored or used as a source for the chemical industry.

[0006] US Pat. No. 3,813,210 A proposes a kiln for converting raw meal into cement clinker. The kiln comprises two parts: a rotary kiln and an elongated, fixed, inclined trough with a perforated floor for supporting the raw meal. The rotary kiln is used to sinter the calcined raw meal into clinker. In the trough, the raw meal is first preheated and then calcined by supplying a stream of hot gases from a combustion chamber below the perforated floor. The calcined raw meal is fed directly from the calcining section of the trough to the inlet of the rotary kiln.

[0007] WO 2017 / 125759 proposes a cement clinker plant with a U-shaped reactor for drying municipal waste by adding preheated raw meal to the first leg of the U-shaped reactor. In the second leg, the dried waste undergoes pyrolysis. The resulting product gas is supplied to a calciner. The two legs are connected by an inclined perforated bottom plate, through which gas is injected in a pulsed manner to enhance the flow of material from the first leg to the second. Summary of the Invention

[0008] The present invention is based on the observation that the teaching of FR 2921059 A1 is conceptual, and its practical implementation reveals new technical problems, one of which is the conveying of calcined raw meal—Geldart C group material—to the raw meal inlet of a kiln (shortly, the kiln inlet) without cooling the calcined raw meal, since the calcined raw meal is no longer transported by the calciner fumes. The technically simplest solution would be to store the calcined raw meal until it has cooled to a temperature that allows easy handling of the calcined raw meal. However, this method is inefficient because the raw meal must be heated again, requiring heating equipment and leading to a significant increase in energy consumption. Therefore, the object of the present invention is to provide a chute plate, a chute, and a method for conveying Geldart C group material, such as calcined raw meal provided by, for example, the RCC process, to the kiln inlet, while maintaining low equipment costs and low operating costs of the apparatus.

[0009] The solution to the problem is provided by the slide plate, slide segment and method according to the respective claims. Advantageous embodiments are the subject matter of the dependent claims.

[0010] This solution is based on the observation that the pre-calcined raw meal is a Geldart C group powder and is therefore very difficult, if not impossible, to fluidize without additional mechanical stirring due to the cohesion between the powder particles. Therefore, air-gravity conveying mechanisms based on fluidization are not promising. Also due to the cohesion, chutes or slides for the calcined raw meal require a slope of at least 60°. These chutes have been used, but their slope imposes limitations on the relative vertical position of the kiln inlet and calciner outlet, since the horizontal distance is actually determined by the position of the already existing preheater tower. The required height of the calciner outlet has a significant impact on the installation costs of the calciner and chute. Moreover, as the height of the calciner increases, the length of the chute increases, and therefore the energy losses also increase. Air-jet conveyor mechanisms are possible, enabling horizontal or even upward conveyance of the raw meal. However, since the air jets must be preheated to the raw meal temperature, typically 850°C to 1000°C, or the raw meal is cooled by the air jets, operating costs increase significantly. Furthermore, the energy consumption and installation costs required to drive fans of corresponding sizes are non-negligible. The conveying screws cannot withstand corrosion and must be cooled, which in turn requires reheating the calcined raw meal.

[0011] The solution to the problems summarized above is a runner plate for a chute for Geldart C group material (or other types of particulate matter), wherein the runner plate has a longitudinal axis. In this regard, it is worth noting that the application of the present invention is not limited to RCC, but can alternatively be used for many other applications and enable a reduction in the construction height limited by the height of a conventional chute. The longitudinal axis is preferably substantially parallel to the conveying direction of the Geldart C group material transported using the runner plate. The runner plate (for short, "plate") has an upward facing surface, which is used to support the Geldart C group material, such as hot calcined raw material. The plate also has a lower surface, which is located on the side of the plate opposite to the upward facing surface. The plate also has a front side surface and a rear side surface, the front side surface preferably at least substantially facing towards the conveying direction, and the rear side surface preferably at least substantially facing against the conveying direction. The front side surface and the rear side surface can connect the upward facing surface and the lower surface. The runner plate is preferably made of ceramic refractory material and / or at least includes ceramic refractory material. The ceramic refractory material has a plurality of through holes which provide fluid communication between a fluid inlet in the lower surface and a fluid outlet in the upward facing surface. The runner plate allows for a preferably very gentle air flow which essentially flows between the upward facing surface and the Geldart C group material deposited on top of the upward facing surface. The air flow almost forms an air cushion between the Geldart C group material and the upward facing surface, thereby reducing the critical angle of the runner for the Geldart C group material on the plate. In practice, the air cushion is not perfect as the gas finds its way through the bed of Geldart C group material. In any case, the process is thought to be understood as a bed of Geldart C group material being formed by the cohesive forces of the material floating on the air cushion. This model is obviously simplified but already provides an idea of ​​why the slope of the runner relative to the horizontal can be significantly reduced to below 60°.

[0012] The present invention can be used not only for conveying hot Geldart C materials, but also for conveying cold Geldart C materials, such as uncalcined raw meal. For example, the present invention can be used in a preheater tower in a cement clinker production line to connect / transfer raw meal from one preheater stage to the next. In this case, the height of the preheater tower can be reduced, which again leads to a significant reduction in construction costs.

[0013] Just to avoid misunderstanding, the critical angle of the slide is the angle at which the Geldart Group C material begins to slide over the grating plate, that is, at lower inclinations of the upwardly facing surface of the slide plate, the Geldart Group C material accumulates on the slide plate, and at steeper angles, the Geldart Group C material slides down the slide plate.

[0014] In preferred examples, the distance d between the boundaries defining at least one of the through-holes in the conveying direction is or is between 0.75 mm and 0.01 mm, such that 0.75 mm ≥ d ≥ 0.01 mm; preferably, 0.5 mm ≥ d ≥ 0.05 mm, and even more preferably, 0.25 mm ≥ d ≥ 0.08 mm. The relatively small size d of the through-holes ensures that the flow rate through the plate is low and that the pressure difference—i.e., the pressure drop—between the pressure below the plate's lower surface and the pressure on the plate's upward-facing surface is greater than the pressure drop between the bottom of the Geldart C material on the upward-facing surface and the space above the Geldart C material. Consequently, the gas flow is substantially limited by the runner plate, and flow inhomogeneities are reduced. Preferred example values ​​for the distance d are d = 0.1 mm or d = 0.2 mm, such that 0.2 mm ≥ d ≥ 0.1 mm is particularly preferred.

[0015] In a particularly preferred example, at least one of the through-holes (particularly preferably, most or even all of the through-holes) is a slot having a slot width w and a slot gap d, wherein the slot width w extends perpendicularly within an angle ±α with respect to the longitudinal axis, and α∈{45°, 40°, 30°, 15°, 10°, 5°, 2.5°, 1°, 0°}, and wherein the slot width w is greater than the slot gap d (w>d). For example, the width w can be n times the gap d (d·n=w), and n>m, m∈{25, 50, 75, 100, 150}. The slots provide a uniform air cushion beneath the particulate matter, which can even be a Geldart C group material.

[0016] The slot gap d is therefore at least substantially the distance d between the boundaries which delimit at least one of the through-openings, ie the distance d between the boundaries of the respective slots in the conveying direction.

[0017] In operation, the slide plate may preferably have a gas flow rate j through the slide plate. g , the gas flow rate j g Equal to or less than 0.1Nm 3 per second (s) and per unit area (m 2 ) The supporting surface of the plate, i.e. Among them, Nm 3 Represents a cubic meter of gas under normal conditions, which is standard pressure P N =1013.25hpa and standard temperature T = 0℃, and m 2 In a particularly preferred embodiment, the gas flow rate is equal to or lower than One of the values. Lower values ​​are preferred. These low gas flow rates are sufficient to significantly reduce the critical angle of the slide for Geldart C group materials on the slide plate, thereby reducing fan installation and operating costs. In addition, potential unintended interactions between the gas and particulate matter are reduced, an example of particulate matter being Geldart C group materials. In the example of transporting hot raw material, for example from a calciner outlet to a kiln inlet, cooling of the hot raw material is reduced even if gas at ambient temperature or only slightly elevated temperature is used to form the gas cushion. In a preferred example, the gas can be heated before being injected into the through-holes of the slide plate. In practice, the support surface of the slide plate is the portion of the upward-facing surface onto which the particulate matter slides during operation of the slide. For example, the slide plate can be positioned to separate the upper and lower channels of a slide section or slide, wherein the bottom surface of the upper channel can be provided by at least a portion of the upward-facing surface of the slide plate. The portion of the slide plate that contributes to the bottom surface is the support surface of the slide plate. In functional terms, the portion of the runner plate that is configured to support particulate matter to be conveyed through the runner is the support surface. In some examples, the entire upwardly facing surface may be considered the support surface. In other examples, the runner plate may extend into a groove in the side wall of the runner, for example, into a groove defined by the refractory cladding of the runner. In these other examples, the portion of the upwardly facing surface that engages into the groove is not configured to support particulate matter, and therefore the engaged portion does not contribute to the support surface of the runner plate. In operation, Geldart C-Group material slides down the upper channel, and gas that reduces the friction between the sliding surface and the Geldart C-Group material is provided to the through-holes in at least one of the runner plates via the lower channel.

[0018] Preferably, the support surface can be a strip-shaped surface that extends at least substantially in the center of the upwardly facing surface and connects the front and rear side surfaces. The width of the strip can be defined by the spacing of the side walls of the slideway. In the event that these side walls do not (yet) exist, the width of the strip can be defined by the width of the area with the through holes.

[0019] Preferably, the pressure gradient Δ between the bottom-facing surface of the skid plate and the upward-facing surface of the skid plate is p↑ Less than or equal to 2 kPa. In the case where the slide plate separates the lower ventilation channel extending below the slide plate from the upper channel above the slide plate, the pressure gradient Δ p↑ =P l -P u ≤2kPa, where P l and P u Denote the gas pressure in the lower channel and the gas pressure in the upper channel, respectively. Particularly preferably, the pressure gradient Δ p↑Less than these 2kPa, such as Δ p↑ ≤1.5kPa, Δ p↑ ≤1kPa, Δ p↑ ≤0.75 kPa. The lower limit of the pressure gradient can be found experimentally: if the flow of Geldart C material stops or fluctuates, the lower limit is found. The lower limit depends on the Geldart C material to be conveyed, the surface roughness of the slide plate and the thickness of the layer, which are the most relevant factors. In addition, the lower limit decreases with increasing the slope angle of the slide. Obviously, if there is no pressure gradient Δ p↑ , then the airflow through the through hole stops, that is, Δ p↑ >0Pa, preferably, Δ p↑ ≥10Pa, Δ p↑ ≥0.1kPa, Δ p↑ ≥0.5kPa or Δ p↑ ≥0.6kPa.

[0020] In a preferred example, the runner plate has at least one fluid outlet of the through-hole, which is closer to the front side surface than the at least one fluid inlet of the through-hole. The airflow leaving the through-hole therefore has momentum in the conveying direction. Therefore, the airflow or at least a portion of the airflow follows the upward-facing surface of the runner plate in the conveying direction (Coanda effect). In a particularly preferred example, at least the forward boundary of the through-hole, i.e., the wall segment defining at least the forward-facing end of the through-hole, merges at least substantially tangentially into the upward-facing surface. Therefore, the airflow adheres particularly well to the upward-facing surface, thereby making it possible to further reduce the gas flow rate and therefore maintain an even higher temperature of the Geldart C group material on the upward-facing surface of the plate.

[0021] Preferably, the underside of the runner plate has at least one recess and / or protrusion, which provides a first stop surface facing toward the front end surface and / or a second stop surface facing toward the rear end surface. The recess and / or protrusion enables the runner plate to be positioned on the inclined support structure, which in turn has corresponding protrusions and / or recesses. The support structure can be referred to as a runner plate support.

[0022] A runner plate can be used as a support plate for hot Geldart C group materials of a conveyor runner (referred to as a "runner"). For example, the runner can include a housing having a housing wall, and the housing wall can surround a circumferentially closed channel. The housing can include a runner plate support for supporting the runner plate in the channel. The runner plate can separate at least a section of the channel into an upper channel and a lower channel. The lower surface can provide a top of the lower channel. The upward-facing surface can provide a bottom of the upper channel. At least one through-hole of at least one runner plate provides fluid communication between the upper channel and the lower channel. The channel can also be referred to as a conduit, that is, the channel has at least substantially parallel channel axes.

[0023] For example, the slide plate support may be a refractory cladding on the inside of the housing, thereby defining the width of the channel. This width may also be the width w of the strip surface of the slide plate mentioned above.

[0024] The first side portion of the lower surface can be located on the first portion of the slide plate support. The second side portion of the bottom surface can be located on the second portion of the slide plate support. Thus, a middle portion of the lower surface can be located between the first side portion and the second side portion. The middle portion provides a lower end for the (at least one) through-hole in the slide plate.

[0025] As noted above, the runner plate can include at least one recess and / or protrusion, for example, on the underside of the runner plate. The runner plate support, such as the refractory cladding, can correspondingly include at least one protrusion and / or recess, wherein the protrusion engages in the recess and provides a form-fitting locking of the runner plate on the runner plate support. This allows the runner plate to maintain its intended position.

[0026] The upward-facing surface of at least one runner plate can support the refractory cladding of the upper channel. For example, the runner plate can also or alternatively have at least one protrusion and / or recess located on the upward-facing side of the runner plate. The protrusion and / or recess can engage with and / or be engaged by a recess or protrusion of the refractory cladding, respectively, thereby preventing the refractory cladding and the runner plate from sliding relative to each other.

[0027] Preferably, the extension of at least one projection parallel to the longitudinal axis is at least 1 mm smaller, preferably at least 2 mm smaller, than the extension of the recess into which the projection engages, also measured parallel to the longitudinal axis. The runway plate support and the runway plate can thus move relative to each other within the limits of a gap defined by the difference in extension parallel to the longitudinal axis. This increases the life of the runway because tensile stresses are reduced. Similarly, in the case of a projection-recess joint between the runway plate and the refractory cladding above the runway plate, preferably the extension of at least one projection parallel to the longitudinal axis is at least 1 mm smaller, preferably at least 2 mm smaller, than the extension of the recess into which the projection engages, also measured parallel to the longitudinal axis.

[0028] In a preferred example, the upwardly facing surface of at least one, at least two or all of the one or more slide plates has an inclination of less than 25° relative to the horizontal. Preferably, the inclination is less than 20° or 15° or 12° relative to the horizontal. Experiments have shown that an inclination of 10° still enables safe transport of hot Geldart C group materials with very low gas flow rates, i.e. very low cooling losses. The lower limit of the minimum inclination angle that still provides reliable transport depends on the gas flow rate and the material to be transported. Based on currently available experimental data, it is believed that 5° (or even slightly lower, such as 4°, 3°) can be considered as a lower limit for Geldart C-group materials, such as raw meal, but operating at these low inclination angles requires an increase in the gas flow rate per unit surface area through the through-holes. If necessary, this increase can be achieved by reducing the pressure drop p ↑ The slope can be further reduced, for example, by an anti-stiction coating of the upwardly facing surface, by further reducing the axial distance of the through-holes, or by other measures that reduce the friction between the slide and the material to be conveyed.

[0029] Furthermore, the slope of the most upstream runner plate or plates can be greater than the slope of at least one of the at least one downstream runner plates. This increased angle ensures that the hot Geldart C material begins to slide over the one or more most upstream runner plates. Stiction is overcome, and the subsequent reduced slope is sufficient to maintain movement of the Geldart C material while keeping the gas flow rate through the through-holes low.

[0030] Additionally or alternatively, the most upstream slide plate or the plurality of upstream slide plates may have more through holes and / or through holes with an increased cross section than at least one of the at least one downstream slide plate. Under conditions of a given pressure difference between the upper and lower sides of the slide plates, both measures increase the gas flow rate per unit surface area of ​​at least one corresponding upstream slide plate and thereby help to avoid blockage of the slide while keeping the gas flow through the downstream slide plates small. Experiments have shown that the risk of slide blockage occurring near the inlet portion of the slide is higher than the risk of slide blockage occurring in the middle section of the outlet portion. Therefore, the risk of slide blockage can be significantly reduced by increasing the inclination of (only) one upstream slide plate and / or by increasing the inclination of a plurality of (preferably a small number of) upstream slide plates, and / or by increasing the gas flow per unit surface area through the upstream or the plurality of (preferably a small number of) upstream slide plates as suggested in the previous paragraphs. The total gas flow through the skid plate remains small, which contributes to low operating costs, and further in the case of conveying hot Geldart C-group materials, unintended cooling of the gas flow is kept to a very low level.

[0031] Another possible way to increase the gas flow through only the most upstream slide plate or multiple upstream slide plates is to divide the lower gas channel extending at the lower side of the slide plate into at least two compartments, for example by a partition wall. Thus, the lower gas channel can have an upstream compartment below the one or more upstream slide plates and a downstream compartment below the one or more upstream slide plates, the upstream compartment and the downstream compartment being separated by the partition wall. In addition to or as an alternative to other measures, the gas flow through one or more upstream slide plates can be increased by providing a higher gas flow per unit sliding surface to the compartment below the upstream slide plate than to the compartment below the downstream slide plate.

[0032] Preferably, the upper channel of the slide comprises at least one gas opening, wherein the gas opening is connected to a compressed gas source, also referred to as a "compressed gas container" or "compressed gas container", via at least one control valve. The compressed gas source is configured to provide gas at a pressure higher than the gas pressure in the upper channel when the control valve is closed. Preferred values ​​of the gas pressure provided by the gas source when the valve is closed are equal to or higher than 50 kPa, and / or 100 kPa, and / or 200 kPa, and / or 300 kPa, and / or 400 kPa, and / or 500 kPa, and / or 750 kPa, and / or higher than the pressure P in the upper channel. u1 MPa. A fluid line can connect the compressed gas source and the gas opening. The control valve is configured to control the flow of gas from the compressed gas source to the gas opening in the upper channel. In other words, the control valve is located in the fluid path from the compressed gas container to the gas opening in the upper channel. Opening the control valve enables a burst of gas to flow from the compressed gas source through the at least one gas opening. This burst of gas can be used to clear the upper channel if it is blocked. Preferably, the duration of the gas burst is short, for example, less than or equal to 200 ms and / or 300 ms and / or 500 ms and / or 1 s and / or 2 s and / or 3 s and / or 4 s and / or 5 s and / or 10 s.

[0033] As is already apparent, preferably, at least one gas opening is located at the upstream end of the upper channel and / or in at least one of the side walls in the upper third, quarter, fifth or tenth portion of the slide. In a preferred example, the gas opening is located in a portion of the side wall delimiting the upper channel. In a particularly preferred example, the opening is located in a portion of the side wall adjacent to the most upstream slide plate or the second most upstream slide plate.

[0034] Preferably, the cross-section of the at least one gas opening is a multiple of the cross-section of the through-hole in the slide plate, for example, greater than or equal to 10 times and / or 20 times and / or 50 times and / or 100 times, 200 times and / or 500 times the cross-section of the through-hole in the slide plate. As a result, the gas flow rate through the gas opening can be much higher than the gas flow rate through the through-hole in the slide plate.

[0035] Multiple runner plates can be aligned to form a sliding surface. In a preferred embodiment, gaskets or any other type of seal are located between the aligned runner plates. This prevents unintended gas flow from beneath the runner plates into the particulate matter, and further reduces the power requirements of the fan operating the runner. Furthermore, potential unintended interactions (e.g., cooling) between the gas and the particulate matter are reduced.

[0036] The runway plate can be manufactured by casting a glaze slip (including an engobe) of a ceramic refractory material in a mold having at least a bottom and sidewalls. After curing, the greenware thus obtained can undergo a heat treatment, commonly referred to as "firing." The heat treatment converts the greenware into a ceramic refractory material. This method thus makes it possible to provide a heat-resistant runway plate made of a ceramic refractory material.

[0037] In a preferred embodiment, a positive form may be inserted into the mold before the glaze slip is cured into the greenware. Preferably, the shape of the positive form corresponds to the shape of at least one of the through-holes of the runner board to be manufactured. In this sense, the positive form is a positive form of at least one through-hole.

[0038] Preferably, the male mold part is made of a thermally degradable material, for example, a cellulose-based material and / or a polymer-based material such as a plastic. In this context, any material that disintegrates during the heat treatment used to convert the greenware into ceramic is considered thermally degradable. Degradation can occur due to evaporation and / or chemical reactions such as combustion, pyrolysis, etc. Alternatively, the male mold part can be made of a soluble material, allowing it to be dissolved before or after firing the greenware. In all these cases, at least one male mold part disintegrates during the heat treatment and / or when exposed to a corresponding solvent, and the disintegration releases the corresponding at least one through-hole during the heat treatment. Thus, after heat treatment and / or treatment of the semi-finished runner plate with a solvent, the runner plate has a through-hole in the same location and orientation as the at least one male mold part did before the heat treatment. For example, many polymeric plastics can be considered thermally degradable materials.

[0039] The at least one male forming element can be held in place and thus supported by a support extending above the mold. Additionally or alternatively, the mold can have at least one support opening configured to receive an end section of the at least one male forming element. Thus, during installation, a portion of the male forming element can engage the support opening, thereby being supported by the mold in a predetermined position and orientation. This method has the advantage that the at least one male forming element extends along the inner contour of the mold and, therefore, along the contour of the runner plate after deformation of the greenware. This prevents unintentional plugging of the through-hole by the greenware and, subsequently, by the refractory material.

[0040] The initially mentioned problem is also solved by a method for conveying hot Geldart C group material on a slide having a sliding surface with at least one through hole, preferably with a plurality of through holes. The method may comprise depositing the Geldart C group material on an upwardly facing surface of the slide, for example, on the upwardly facing side of a slide plate. The method may further comprise the step of: adjusting the gas flow rate to g The gas flow rate j is provided to the upwardly facing surface of the slide through the through holes. g Equal to or less than 0.5Nm 3 Gas per second (s) and unit surface area (m 2 ) sliding surface. In a preferred example, j g equal to or lower than one of the.

[0041] In summary, the claimed invention makes it possible to reduce the angle of the chute (measured with respect to the horizontal plane) for conveying hot Geldart C powder, for example calcined raw material, to about 20°, or even lower. Some of the advantageous embodiments described in the dependent claims make it possible to further reduce the angle to about 10°, thereby reducing the installation costs and, due to the low gas flow through the through-holes, also the operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In the following, the present invention will be described by way of examples of embodiment with reference to the accompanying drawings, by way of example, without limiting the general inventive concept.

[0043] Figure 1 Shown is a perspective view of a chute section of a chute for Geldart Group C material.

[0044] Figure 2 A side view of a slide section is shown.

[0045] Figure 3 The slideway section is shown in FIG. Figure 2 Cross-section view on the indicated AA plane.

[0046] Figure 4 A longitudinal cross-section of the lower part of the slide section is shown.

[0047] Figure 5 A perspective view of the lower portion of a slide section is shown.

[0048] Figure 6 A side view of another slide section is shown, which can be used with Figure 1 and Figure 2 Slide section combination.

[0049] Figure 7 Shown Figure 6 A top view of the slide section.

[0050] Figure 8 Shown Figure 6 and Figure 7 The slide section along Figure 7 Cross-sectional view of plane AA in FIG.

[0051] Figure 1 The segments of the chute 1 in FIG. 1 can also be considered short chutes 1 , but in practice, typically, multiple segments depicted can be connected to form a longer chute for Geldart Group C materials. Thus, the chute 1 can have multiple (at least one) segments depicted. The chute 1 extends at least substantially parallel to the longitudinal axis 2 and is configured to convey Geldart Group C materials in a conveying direction 3.

[0052] Figure 1 The slide in FIG has a housing 30 having a housing wall 31. The housing wall 31 can be, for example, sheet metal that is easy to process. The housing wall can preferably have an upper housing part 311 and a lower housing part 313 that can be attached to each other (preferably releasably) to enclose a channel having an upper part 41 and a lower part 43 (see FIG. Figure 3 ). As shown, the upper shell part 311 and the lower shell part 313 can have an upper flange 351 and a lower flange 353, respectively, so that the upper shell part 312 and the lower shell part 313 can be attached to each other (preferably releasably). Additionally or alternatively, the slide 1 can have a front flange 36 and a rear flange 37. Preferably, the front surface of the front flange 36 is at least a part of the projection of the rear surface of the rear flange 37 parallel to the longitudinal axis 2. By simply connecting the front flange 36 of the first slide 1 to the rear flange 37 of the second slide 1, this easily connects the slides 1 together, thereby forming a relatively longer slide 1 and converting the first slide 1 and the second slide 1 into slide sections. Of course, the rear surface of the rear flange 37 can also be a part of the projection of the front surface of the front flange 36 parallel to the longitudinal axis 2.

[0053] The inner side of the housing wall 31 is preferably a thermal insulation layer 38, in particular as Figure 1 and Figure 3 As shown. The thermal insulation layer 38 can be, for example, a calcium silicate material or any other material with a low heat transfer coefficient. In a particularly preferred example, the thermal insulation layer 38 can be made of or include microporous thermal insulation materials, which provide a relatively low thermal conductivity k, which is in the range of approximately In the case where conventional insulating materials are used, the thickness of the thermal insulation layer 38 is preferably increased accordingly.

[0054] The insulation layer 38 comprises an upper insulation part 381, which is located in the upper part 311 of the housing wall, and a lower insulation part 383, which is located in the lower part 313 of the housing wall. Each of the two insulation parts forms a U-profile having a middle leg to which two side legs are attached. In the case of installation, as Figure 1 and Figure 3 As shown, the free ends of the side legs of the upper insulating portion may face the corresponding free ends of the side legs of the lower insulating portion.

[0055] The shell 30 may preferably have a refractory cladding 50. The upper shell portion may have an upper cladding, and the lower shell portion may have a lower cladding. Figure 4As can be seen in FIG, the refractory blanket 50 protects the optional insulation layer 38 from abrasion by the Geldart C group material. In the event that the insulation material 38 has been omitted, the optional refractory blanket 50 can protect the shell wall 31. Therefore, the refractory blanket 50 can be located on the inside of the shell wall 31. The optional insulation material 38 can be located between the refractory blanket 50 and the shell wall 31.

[0056] The lower portion of the refractory cladding can have a U-shaped cross-section, comprising a cladding center leg 531 and two cladding side legs 532. As shown, the cladding center leg 531 can be supported on the upward-facing surface of the center leg of the optional lower insulation section 383. If the insulation section 383 is omitted, the cladding center leg can be supported on or by the bottom of the lower portion 313 of the shell wall. The two cladding side legs 532 of the lower portion of the refractory cladding 53, referred to as lower cladding side legs 532, can extend toward the upper portion 311 of the shell wall. Each lower cladding side leg 532 can provide an upward-facing surface. The upward-facing surfaces of the cladding side legs 532 can support the runway panel 10.

[0057] The runner plate 10 extends along the longitudinal axis 2 and has an upwardly facing surface 11 for supporting Geldart C group material, such as hot calcined raw meal. The runner plate 10 also has a lower surface 13, a front side surface 12, and a rear side surface 14. The runner plate 10 may be made of a ceramic refractory material.

[0058] The lower surface 13 of the board 10 has side portions that can rest on the lower cladding side legs 532. Thus, the lower cladding side legs 532 can support the skid board 10.

[0059] The lower cladding portion and the runway plate 10 may enclose the lower channel 43. For example, the lower channel 43 may be defined by a central band of the lower surface 13 of the runway plate 10, the inwardly facing surfaces of the lower cladding side legs 532, and the upwardly facing surfaces of the lower cladding middle legs 531 (see FIG. Figure 4 and Figure 5 ). The central band of the lower surface 13 of the panel 10 is therefore located between the side portions of the lower surface 13 of the panel 10 that are located on the upwardly facing surfaces of the lower cladding side legs 532 (see Figure 3 ).

[0060] like Figure 4 and Figure 5As can be seen in the figure, the lower cladding side legs 532 may have protrusions 533 that engage in complementary shaped recesses 123 in the lower surface 12 of the runner plate, thereby preventing the runner plate 10 from sliding parallel to the longitudinal axis 2. The maximum extension of the protrusion is preferably slightly less than the space provided by the corresponding recess, thereby allowing the runner plate 10 to float on the lower refractory side legs 532 to a limit given by the distance between the extension of the recess and the protrusion. Between the upwardly facing surface 11 of the runner plate 10 and the upper cladding side legs is preferably a gasket.

[0061] The shell can also form an upper channel 41. As in the depicted example, the shell can have an upper cladding 51. The upper cladding can have an inverted U-shape with a center leg 511 from which two side legs 512 extend downwardly to the upward-facing surface of the ride board 10. The lower side of the center leg 511 defines the top of the upper channel 41. A portion of the upward-facing surface 11 of the ride board, the so-called center band of the upward-facing surface 11 of the board 10, provides the bottom of the upper channel 41, and the inward-facing sides of the upper cladding side legs 512 define the width of the upper channel and, in this example, also the width of the center band. The width of the upper channel 41 is preferably at least substantially the same as the width of the lower channel 43.

[0062] like Figure 4 and Figure 5 As shown, the slide plate 10 may preferably have a plurality of through holes 20 extending from an inlet opening 23 in the lower surface 13 of the slide plate to an outlet opening 21 in the upwardly facing surface 11 of the slide plate. As in the preferred example depicted, the through holes 20 may be slits having a slit width w, the slit extending at least substantially perpendicular to the longitudinal axis 2. The slit gap d is preferably at least substantially constant along the slit width. As can be seen, the slit width w is preferably m times the slit gap d, where m is greater than 1 and is not necessarily an integer, i.e. m>1 and m∈R, where R represents the set of real numbers. Preferably, the through holes are inclined in the conveying direction, i.e. the outlet opening 21 is closer to the front side surface 12 of the slide plate 10 than the inlet opening 23 of the corresponding through hole. This inclination of the through holes 20 has been shown to reduce the gas flow rate required to maintain the flow of Geldart C group material.

[0063] It has been observed that the particles of Geldart C group material form brittle but very soft clusters. These clusters can be considered as lumps of cohesive condensation of the particulate matter. The reduction in the critical angle is believed to be caused by an air cushion, which is formed by the air flow between the clusters of the runner plate and the bed of particulate matter. It has been observed that holes, cracks or other types of voids are formed between these clusters by the air flow. The gas then flows through these voids to the upper side of the bed formed by the particulate material. Therefore, the particulate material is not fluidized by the air flow. It can be said that the air cushion reduces the cohesive force of the particulate matter to the top surface of the runner plate and therefore reduces the friction. In other words, the air flow via the through holes 20 provides a reduction in the cohesive force of the particulate matter to the top surface 11 of the runner plate 10 and therefore reduces the friction between the top surface 11 and the bed of particulate matter. This reduced friction directly leads to a significant reduction in the required minimum inclination angle of the runner. Angles of 25°, 20°, 15°, 12°, and 10° or less have been found to be sufficiently steep to reliably convey even Geldart Group C materials. Increasing the gas flow rate through the through-holes provides a decrease in the minimum angle of inclination for reliable conveyance of Geldart Group C materials.

[0064] In operation, the flow of Geldart C group material can be unloaded to the first end portion of the upper channel 41. The Geldart C group material can thus be deposited on the upwardly facing surface 11 of the slide plate 10. In addition, the lower channel 43 can be provided with a gas pressure p l , the gas pressure p l Greater than the gas pressure p in the upper channel 41 u , so preferably p l >p u Due to the pressure gradient Δp ↑ =p l -p u , thereby providing an air flow through the through-holes 20. This air flow reduces the cohesion between the Geldart C group material (or any other particulate matter) and the upwardly facing surface 11 of the slide plate 10. The Geldart C group material can thus slide down a slide that is only slightly inclined. "Slightly inclined" in this context means that inclinations of 25°, 20°, 15°, 12° and 10° or less can be achieved relative to the horizontal plane, with some experiments showing that this can be reduced down to 10° and slightly below this inclination. These inclinations are much smaller than the inclinations of prior art slides, which typically have an inclination of at least 60°, and these inclinations contribute to a significant reduction in the construction costs of the corresponding plants.

[0065] Preferably, the housing 10 has an inspection and maintenance opening 60. Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5 , the opening 60 is shown as being closed. The opening 60 can also be used as a gas inlet opening to provide gas flow to the lower channel 43.

[0066] Figures 6 to 8 Another chute section 1 of a Geldart C group material conveying chute is shown. Figures 6 to 8 The slideway section can be mounted, and is therefore preferably configured to be mounted to Figure 1 For example, Figures 6 to 8 As shown, Figure 1 and Figure 2 The rear end flange 37 of one slide section can be fixed to the front end flange 36 of another slide section 1 by bolts.

[0067] Figures 6 to 8 The chute section in has a housing 30 having an inlet 5 for receiving particulate matter, such as Geldart C group material. Figure 8 As can be best seen in FIG, the inlet 5 is located above the slide plate 110 and enables the feeding of granular matter into the upper channel 41. The bottom of the upper channel 41 is delimited by the slide plate 110 and the slide plate 10, which have a through hole 20, which is only Figure 6 , as section AA extends through an optional continuous area. Figures 1 to 3 The slide plates 10 of the slide sections are substantially identical. Figures 1 to 3 The details of the slide plate 10 of the slide section are shown in Figure 4 and Figure 5 Depicted in and Figures 1 to 5 The description of the slide board 10 provided in the context of Figure 6 and Figure 8 The slide plate 110 and the slide plate 10 are shown read out.

[0068] Figure 6 and Figure 8The slide plate 110 in the embodiment is located upstream of the slide plate 10 and may preferably have a steeper inclination than the downstream slide plate 10. This increased inclination contributes to more reliable operation of the slide and a reduced average slope of the slide. Experiments have shown that slide blockage (e.g., due to sticky particulate matter) always begins at the upstream end of the slide. Once the particulate matter slides down the slide, a smaller angle (a less steep slope) is even sufficient to maintain the movement of Geldart C group material. Therefore, the steeper inclination of the upstream slide plate 110 makes it possible to further reduce the inclination of the subsequent slide plate 10, thereby further reducing the height required to install a slide with a given horizontal extension. In any embodiment, the upstream slide plate 110 may have a greater number of through holes and / or through holes with a larger total cross-section than the immediately downstream slide plate or another downstream slide plate. Both measures contribute to an increase in the gas flow rate through the upstream slide plate 110 and thereby reduce the risk of slide blockage.

[0069] and Figures 1 to 3 The upper passage 41 is preferably delimited on the top and sides by a refractory cladding 50 comprising an upper cladding side leg 511 and an upper cladding middle leg 512. Between the outer shell wall 31 and the refractory cladding 50 may preferably be an insulation layer 38 (see Figure 8 ).

[0070] exist Figure 8 In the embodiment, the slide plate 110 and the slide plate 10 separate the upper channel 41 from the lower channel 43. Therefore, the lower channel 43 extends below the slide plate 110 and the slide plate 10. Figure 3 The lower channel 3 is very similar to the lower channel in the embodiment of the present invention, with the bottom and sides of the lower channel 3 being bounded by a lower cladding middle leg 531 between two lower cladding side legs 532. Likewise, an optional insulation layer 38 may preferably be located between the shell wall 31 and portions of the lower cladding.

[0071] The lower passage 43 may extend into the gas inlet 45 and thus may be in fluid communication with the gas inlet 45 (see Figure 8 By attaching a gas source to the gas inlet 45, gas can be injected into the lower channel 43, thereby providing a pressure gradient between the lower channel 43 and the upper channel 41. Consequently, a portion of the gas can flow through the through-holes 20 to the upward-facing surfaces 11 of the runner plates 110, 10, and can reduce friction between the runner plates 110, 10 and particulate matter that may have been injected into the upper channel 41 via the particulate matter inlet 5.

[0072] As is already evident, in the case where the distance over which the material is to be transported is sufficiently short, a single chute segment 1, whether it is Figures 1 to 3Slide section 1 or Figures 6 to 8 In the case of longer distances, a plurality of slide sections can be attached to each other to form a correspondingly longer slide.

[0073] General Notes:

[0074] The terms "at least substantially constant", "at least substantially the same", etc. used above are to be understood as meaning that constant or the same size is preferred, but deviations are acceptable. Typically, acceptable deviations are within one of ±20%, ±15%, ±10%, ±5%, ±2.5% and ±1%, with the lower value being preferred.

[0075] As used above, the terms "at least substantially parallel", "at least substantially perpendicular", or "at least substantially orthogonal" are used to indicate that parallel or perpendicular (orthogonal) is preferred, but deviations may be acceptable. Generally, acceptable deviations from the intended direction or orientation, regardless of the application, may be within one of ±30°, ±20°, ±15°, ±10°, ±5°, ±2.5°, and ±1°, with lower values ​​being preferred.

[0076] Reference Signs List

[0077] 1 Slideway (segment) for Geldart C group materials (segment)

[0078] 2 Longitudinal axis

[0079] 3 Conveying direction

[0080] 5 material entrance

[0081] 10 slide board

[0082] 110 slide board

[0083] 11 Upward-facing surface of the guide rail

[0084] 12 Front surface of the guide plate

[0085] 13 Lower surface of the guide plate

[0086] 14 Rear surface of the guide plate

[0087] 20 through holes

[0088] 21 Fluid outlet

[0089] 23 Fluid inlet

[0090] 30 Shell

[0091] 31 Shell wall

[0092] 311 Upper part of the housing wall (delimiting the upper channel)

[0093] 313 Lower portion of housing wall (delimiting lower channel)

[0094] 351 upper flange

[0095] 353 lower flange

[0096] 36 front flange

[0097] 37 rear end flange

[0098] 38 Insulation

[0099] 381 Upper insulation part

[0100] 383 lower insulation part

[0101] 41 Upper Passage

[0102] 43 Lower Passage

[0103] 45 Gas inlet of lower channel

[0104] 50 Refractory Cladding

[0105] 511 Upper Cladding Middle Leg

[0106] 512 Upper cladding side legs

[0107] 531 Lower cladding middle leg

[0108] 532 lower cladding side legs

[0109] 533 Protrusion

[0110] 60 opening

Claims

1. A slideway plate for a slideway (1) for Geldart C group materials, wherein: The runner plate has a longitudinal axis (2), an upward facing surface (11), a lower surface (13), a front side surface (12), and a rear side surface (14), wherein the upward facing surface (11) is for supporting the Geldart C group material, wherein the runner plate is made of a ceramic refractory material, and wherein the ceramic refractory material has a plurality of through holes (20), wherein the plurality of through holes (20) provide fluid communication between a fluid inlet (23) in the lower surface (13) and a fluid outlet (21) in the upward facing surface (11), characterized in that the fluid outlet (21) of at least one of the through holes (20) is closer to the front side surface (12) than the fluid inlet (23) of the at least one of the through holes (20); And wherein the lower surface (13) has at least one recess and / or protrusion (533), which provides a first stop surface facing toward the front surface (12) and / or a second stop surface facing toward the rear surface (14) so ​​as to limit movement parallel to the longitudinal axis (2).

2. The slide board according to claim 1, wherein: At least one of the through holes (20) is a slot having a slot width w and a slot gap d, wherein the slot width w extends perpendicularly within an angle of ±α with respect to the longitudinal axis (2), α∈{45°, 40°, 30°, 15°, 10°, 5°, 2.5°, 1°, 0°}, and wherein the slot width w is greater than the slot gap d.

3. The slide board according to claim 1 or 2, characterized in that: A gap d between boundaries defining at least one of the through holes (20) in the conveying direction is less than 0.75 mm.

4. A slideway (1) for hot Geldart C group materials, characterized in that The slide (1) comprises at least one slide plate according to any one of claims 1 to 3.

5. The chute (1) for hot Geldart C group materials according to claim 4, characterized in that The slide (1) comprises a housing (30) having a housing wall (31), wherein the housing wall (31) surrounds a channel, - the housing has a slide plate support for supporting the slide plate in the channel, - the slide plate separates at least a section of the channel into an upper channel (41) and a lower channel (43), wherein the lower surface (13) provides a top of the lower channel (43), and wherein the upwardly facing surface (11) provides a bottom of the upper channel (41), and wherein a through hole (20) provides fluid communication between the upper channel (41) and the lower channel (43).

6. The chute (1) for hot Geldart C group materials according to claim 5, characterized in that The slide plate support is a refractory cladding, and the refractory cladding is used to limit the width of the channel; - a first side portion of the lower surface (13) is located on a first portion of the runway plate support and a second side portion of the lower surface is located on a second portion of the runway plate support, - A middle portion of the lower surface (13) is located between the first side portion and the second side portion.

7. A chute (1) for hot Geldart C group materials according to claim 5 or 6, characterised in that The runway plate support has at least one protrusion and / or recess, which engages in at least one protrusion and / or recess of the runway plate, wherein the extension of the at least one protrusion parallel to the longitudinal axis (2) is at least 1 mm smaller than the extension of the recess into which the protrusion engages, also measured parallel to the longitudinal axis.

8. The slideway according to any one of claims 4 to 6, characterized in that - at least one, at least two or all of the upwardly facing surfaces (11) of one or more runner panels have an inclination of less than 25° relative to the horizontal, and / or The slope of the most upstream runner plate is greater than the slope of at least one downstream runner plate.

9. The slideway according to claim 5 or 6, characterized in that: The upper channel (41) comprises at least one gas opening connected to a container of compressed gas via at least one valve.

10. A method for conveying Geldart C group materials, characterized in that The method comprises: - depositing the Geldart Group C material on the upwardly facing surface of a slide according to any one of claims 4 to 9, and - Every m 2 Sliding surface less than 0.5Nm per second 3 A gas flow of gas is provided through the through holes (20) to the upwardly facing surface (11) of the slide.

11. The method according to claim 10, characterized in that The blower is controlled to provide a gas pressure gradient Δ between the upward facing surface (11) and the lower surface (13) of the skid plate. p↑ , wherein the gas pressure gradient Δ p↑ Less than or equal to 2kPa, that is, Δ p↑ ≤2kPa.

12. The method according to claim 10 or 11, characterized in that The Geldart Group C materials are calcined, partially calcined or uncalcined cement clinker raw meal.

13. A method for conveying Geldart C group materials on a chute (1), characterized in that The slide (1) comprises at least one slide plate according to any one of claims 1 to 3, or wherein the slide (1) is a slide (1) according to any one of claims 4 to 9, and / or wherein the method is the method according to claim 10.

14. The method according to claim 13, characterized in that The blower is controlled to provide a gas pressure gradient Δ between the upward facing surface (11) and the lower surface (13) of the skid plate. p↑ , wherein the gas pressure gradient Δ p↑ Less than or equal to 2kPa, that is, Δ p↑ ≤2kPa.

15. The method according to claim 13 or 14, characterized in that The Geldart Group C materials are calcined, partially calcined or uncalcined cement clinker raw meal.

16. Use of a slide board according to any one of claims 1 to 3, characterized in that: The gas pressure gradient Δ between the upward-facing surface (11) and the lower surface (13) p↑ is selected to be less than or equal to 2 kPa, i.e. Δ p↑ ≤2kPa.

17. Use of a slide (1) according to any one of claims 4 to 9, wherein: The slide plate is located between a lower channel (43) and an upper channel (41), and the slide plate provides a boundary between the lower channel (43) and the upper channel (41), wherein at least a portion of the upwardly facing surface (11) provides a bottom surface of the upper channel (41), and characterized in that the gas flow rate through the slide plate is selected to be less than 0.5 Nm 3 per second and per m 2 The bottom surface of the upper channel (41), i.e. Among them, Nm 3 Represents a cubic meter of gas under normal conditions, where the normal condition is standard pressure P N =101.325kPa and standard temperature T=0℃.

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