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WO2025008398A1 - Refroidisseur pour refroidir un matériau chaud en vrac, en particulier du clinker de ciment - Google Patents

Refroidisseur pour refroidir un matériau chaud en vrac, en particulier du clinker de ciment Download PDF

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Publication number
WO2025008398A1
WO2025008398A1 PCT/EP2024/068726 EP2024068726W WO2025008398A1 WO 2025008398 A1 WO2025008398 A1 WO 2025008398A1 EP 2024068726 W EP2024068726 W EP 2024068726W WO 2025008398 A1 WO2025008398 A1 WO 2025008398A1
Authority
WO
WIPO (PCT)
Prior art keywords
plank
planks
cooling
bulk material
section
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/EP2024/068726
Other languages
German (de)
English (en)
Inventor
Uwe Bock
Uwe Sprinz
Corinna WOLTERS-KACKMANN
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Claudius Peters Projects GmbH
Original Assignee
Claudius Peters Projects GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Claudius Peters Projects GmbH filed Critical Claudius Peters Projects GmbH
Publication of WO2025008398A1 publication Critical patent/WO2025008398A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D15/00—Handling or treating discharged material; Supports or receiving chambers therefor
    • F27D15/02—Cooling
    • F27D15/0206—Cooling with means to convey the charge
    • F27D15/0213—Cooling with means to convey the charge comprising a cooling grate
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B7/00—Hydraulic cements
    • C04B7/36—Manufacture of hydraulic cements in general
    • C04B7/43—Heat treatment, e.g. precalcining, burning, melting; Cooling
    • C04B7/47—Cooling ; Waste heat management
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B7/00—Rotary-drum furnaces, i.e. horizontal or slightly inclined
    • F27B7/20—Details, accessories or equipment specially adapted for rotary-drum furnaces
    • F27B7/38—Arrangements of cooling devices
    • F27B7/383—Cooling devices for the charge
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D15/00—Handling or treating discharged material; Supports or receiving chambers therefor
    • F27D15/02—Cooling
    • F27D15/0206—Cooling with means to convey the charge
    • F27D15/0213—Cooling with means to convey the charge comprising a cooling grate
    • F27D15/022—Cooling with means to convey the charge comprising a cooling grate grate plates
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D15/00—Handling or treating discharged material; Supports or receiving chambers therefor
    • F27D15/02—Cooling
    • F27D15/0206—Cooling with means to convey the charge
    • F27D15/0213—Cooling with means to convey the charge comprising a cooling grate
    • F27D15/022—Cooling with means to convey the charge comprising a cooling grate grate plates
    • F27D2015/0233—Cooling with means to convey the charge comprising a cooling grate grate plates with gas, e.g. air, supply to the grate

Definitions

  • the invention relates to a device for cooling hot bulk material, in particular cement clinker, by means of a cooling gas.
  • the device comprises a cooling grate which conveys a layer of the bulk material from a feed end in a conveying direction to a discharge end and through which cooling gas flows, on which the bulk material to be cooled rests.
  • the cooling grate comprises several planks which are moved forwards and backwards in the conveying direction alternately by a stroke length, the drive of which is controlled in such a way that at least two adjacent planks are moved simultaneously in the forward stroke and not simultaneously in the return stroke.
  • Such cooling devices serve to cool bulk material using gas, in that the bulk material is placed as a bed on a cooling grate and transported along it, while gas is supplied from below the cooling grate for cooling.
  • the cooling gas which is typically cooling air from the lower space of the grate, rises through the cooling grate into the bulk material bed and cools it in the process.
  • the cooling grate has three functions in relation to the bulk material. One function is to support the bulk material to form a material bed, another is the surface for introducing the cooling air, and the other is a transport function for conveying the bulk material from a feed end to a discharge end.
  • Various basic designs have become known for implementing the functions.
  • planks Of interest here is the design with several planks extending in the conveying direction, which are moved back and forth alternately.
  • One difficulty with this conveying principle is that the planks and their surface are exposed to great stresses, namely because of the at least initially or high temperatures of the goods to be cooled and abrasion, particularly with sharp-edged goods such as clinker. This high load leads to considerable wear of the planks.
  • a high cooling effect is important, which is determined, among other things, by the cooling gas throughput through the cooling grate with its cooling gas passage openings and, on the other hand, an efficient and low-wear conveying along the cooling grate by means of the movement of the planks.
  • Ventilation slots are arranged in the space between the long sides of the planks, which extend over the entire length of the plank. They act as air passage openings for the cooling gas. They are provided with a special side-blow profile in order to minimize unwanted entry of bulk material and thus grate fall-through into the grate space. The surface of the planks is swept over by the escaping cooling gas.
  • a protective layer on the planks has the advantage that it offers good protection for the surface of the planks. This can reduce wear on the surface of the planks, particularly in the case of hot, aggressive bulk materials such as clinker.
  • the protective layer has the disadvantages that it creates a flow resistance for the cooling gas flowing upwards from below through the cooling grate and that, at least on the return stroke, it generates a disruptively high frictional force on the bulk material. The latter requires different dimensions of the steel structure and a more powerful drive. This also leads to compaction of the bulk material on the return stroke, which creates additional flow resistance for the cooling gas flowing through the cooling grate, thereby increasing the inherent pressure losses in the cooling gas supply.
  • a smooth design of the planks without a protective layer offers the advantage that only a small return stroke force is required and, due to the lack of a protective layer, only a small pressure loss occurs.
  • the disadvantages are increased wear as a result of the aggressive stress caused by abrasive bulk material. Special materials This disadvantage can be mitigated, but this is costly.
  • Another disadvantage is the increased sensitivity of the plank surface to thermal stress from the hot bulk material bed due to the lack of a protective layer. This becomes a particular risk if the cooling gas supply fails, which then leads to thermal damage to the planks very quickly due to the direct thermal contact between the planks and the hot bulk material.
  • rust penetration can also be a problem, which can be counteracted by high gas speeds, but this leads to a quadratic increase in the inherent pressure losses.
  • a further type of construction is known (DE 10 2010 055 825 B4) in which the planks are designed along their length with zones of rough surface formed by an autogenous wear protection layer, and with zones of smooth surface, with the zones alternating several times.
  • the average coefficient of friction between the bulk material to be cooled and the top of the plank is smaller than in the zone with the autogenous wear protection layer on the plank.
  • a device for cooling hot bulk material in particular cement clinker, by means of a cooling gas, which has a cooling grate through which cooling gas flows and which conveys a layer of the bulk material from a feed end in a conveying direction to a discharge end
  • the cooling grate comprises several planks which are moved forwards and backwards in the conveying direction by a stroke length, the drive of which is controlled in such a way that at least two adjacent planks are moved simultaneously in the forward stroke and non-simultaneously in the return stroke, wherein the planks form a substantially flat support surface for the bulk material
  • at least one plank is designed as a hybrid plank with a different design of the plank surface, which
  • a starting section and/or end section comprising a protective layer of bulk material arranged on the plank surface, whereby an increased coefficient of friction with the bulk material is formed compared to the middle section.
  • the essence of the invention lies in the idea of not providing the planks of the cooling grate with a uniform surface, but rather providing them in their main section (which includes at least the middle section of the plank) with plate covering with a smooth, essentially flat surface for supporting the bulk material (this is also referred to as flat plate covering) and only covering the planks at another specific location, namely outside the at least
  • the plank is to be designed in a central section extending half the length of the plank, with a receptacle for a protective layer of bulk material.
  • This specific location can be a starting section of the plank, or an end section of the plank, or a combination of both, i.e. the starting and end sections of the plank.
  • the panel covering has a smooth surface, and is therefore not provided with a protective layer of bulk material according to the invention (smooth panel covering).
  • the surface used to support the bulk material is therefore either formed by the panel covering, which according to the invention does not have a protective layer of bulk material, or by such a protective layer.
  • the coefficient of friction between this smooth panel covering and the bulk material is smaller than that between the protective layer and the bulk material.
  • the initial section which is arranged immediately in front of the middle section in the conveying direction
  • the middle section extends over a large part (at least half) of the longitudinal extension of the plank and thus forms a main section. It is provided with the smooth plate covering throughout. Due to the smooth plate covering, no protective layer is formed on the middle section, it is free of a protective layer. Since the cooling gas does not have to cross a protective layer and consequently its flow resistance is eliminated, the pressure loss for the The cooling gas is guided from the bottom of the grate through the plank into the bulk material to be cooled.
  • the middle section has no protective layer, only a lower force is required in the return stroke compared to a moving floor with a continuous protective layer, i.e. where the protective layer also exists in the middle section.
  • a protective layer is provided in the critical beginning/end section. This means that the stress and therefore the wear on the planks at these highly stressed points can be minimized. Additional armoring of the plank surface to protect against thermal and abrasive stress is not required, which saves effort. Although there is a local increase in pressure loss at these points due to the protective layer, this is significantly reduced compared to previous designs with a continuous protective layer in accordance with the state of the art because the protective layer is only provided on parts of the plank surface.
  • the driving force required for the return stroke is reduced, which also enables the drive, in particular special hydraulic cylinders and corresponding hydraulic units, to be made smaller and the necessary steel structure to accommodate the cooling grate and its drive to be made lighter.
  • the invention thus enables improved operating behavior, in particular a reduction in pressure losses, while at the same time maintaining a high level of wear protection, whereby the requirements for the drive and steel construction are also reduced.
  • the manufacture and operation of the cooling grate are considerably improved in the manner according to the invention, namely the targeted arrangement of the protective layer in such a way that the protective layer is only arranged in the start/end section, but not in the middle section of the planks of the cooling grate.
  • a starting section is understood to be an area of the cooling grate that is arranged in front of the middle section in the conveying direction. Typically, this is the area in which the bulk material is fed onto the cooling grate (feed end).
  • An end section is understood to be an area of the cooling grate that is arranged after the middle section in the conveying direction. Typically, this is the area in which the bulk material is discharged from the cooling grate (discharge end).
  • planks extend lengthwise in the conveying direction. They are provided with cooling gas passage openings in the beginning, middle and end sections to ventilate the bulk material with cooling gas.
  • the stroke length is the distance by which the planks are moved forwards during a forward movement and backwards during a return stroke. If the stroke length is adjustable, the largest stroke length is the maximum stroke length.
  • a smooth surface is understood to be a flat, unroughened, homogeneously closed surface made of a material, in particular a metal surface without protruding structures.
  • Technically necessary openings, such as those for ventilation slots or fastening devices, are not taken into account here. Thanks to this smoothness, it has a lower coefficient of friction with the bulk material than a rough surface, such as the protective layer against the bulk material.
  • the plate covering has such a smooth surface on its support surface for the bulk material and thus forms a smooth plate covering.
  • the initial and/or final section with the protective layer are expediently designed in such a way that they each have a length that is at least 0.5 times the maximum stroke length, preferably at least 0.9 times.
  • the sections that are particularly subject to high thermal loads The planks at the beginning and end are therefore much better protected.
  • a relatively short protective layer is sufficient because when a plank is pulled back by a full stroke length, the bulk material from the neighboring planks can flow off laterally into the gap created, whereby this still happens in the end section of the neighboring planks protected by the bulk material layer.
  • the protective layer in the area of the beginning and/or end section is preferably no longer than 6 times, more preferably no longer than 12 times the stroke length; with an adjustable stroke length this is related to the maximum possible.
  • the initial section preferably has a greater length than the final section. This takes into account the fact that the thermal load in the initial section is very high and that the effective length of the protective layer is reduced during the return stroke movement, in particular by passing under a feed ramp.
  • receiving troughs in the start and/or end sections are either filled in a targeted manner or material is deposited which forms the protective layer.
  • the receiving troughs can be filled completely or partially with bulk material, for example a layer of gravel material. It can also be provided that part of the bulk material is caught in these receiving troughs during operation, thereby creating an autogenous protective layer.
  • a combination can also be provided, in particular partial filling with another bulk material at the bottom of the receptacles and, if necessary, an autogenous protective layer made of the bulk material on top.
  • the receiving trays are expediently provided with longitudinal and/or transverse subdivisions. This allows the protective layer to be held better. It is advantageous for the longitudinal and transverse subdivisions to be the same height so that their respective upper edges are level.
  • the plate surface in the middle section is at the same level as the surface formed by the protective layer in the initial and/or final sections.
  • this applies to the operating state when the autogenous protective layer is formed. Thanks to this level equality, the bulk material is conveyed and cooled on the planks without any height offset.
  • planks of the device are expediently designed as hybrid planks. However, it is not essential that all planks of the cooling grate are designed as hybrid planks, although in a preferred embodiment all planks can be designed this way.
  • the cooling grate can also advantageously have further planks, in particular also planks that are not hybrid planks. It is advantageous for such non-hybrid planks to be provided with a continuous smooth plate covering in order to minimize the pressure loss for the cooling gas.
  • additional planks can be provided which are provided with a protective layer of bulk material throughout.
  • This can be advantageously provided especially in places where there is a risk of increased thermal stress on the respective plank.
  • edge planks plane on the side edge of the cooling grate, edge plank
  • this is the edge plank on which a higher proportion of the fine fraction of the bulk material.
  • the fine fraction is susceptible to fluidization by the cooling gas, which greatly increases the flow rate and as a result the affected bulk material remains red-hot and extends along the plank like a red-hot river (known in specialist circles as the "Red River” phenomenon).
  • Red River red-hot river
  • the additional plank is particularly advantageous with regard to a fine fraction and the ever-present risk of a localized cooling fault.
  • an increased pressure loss for the cooling gas does occur, but this pressure loss leads to reduced ventilation in the critical area, which reduces the fluidization of the bulk material and thus the flow rate, which is increased with the "Red River".
  • the rough protective layer reduces the conveying speed on this plank, resulting in a slower feed rate with reliable cooling of the bulk material on this plank. Since the bulk material on the edge plank is typically slowed down by friction on the side wall anyway, the slower transport there does not result in any relevant disadvantage.
  • Planks that are more prone to the formation of "red river” do not always need to be designed as additional planks with a continuous protective layer. Often a hybrid plank is sufficient for safe handling. It can therefore be useful if at least one edge plank is designed as a hybrid plank. Preferably, at least one plank immediately adjacent to the edge plank should not be designed as a hybrid plank, but should be designed with a continuous smooth Plate covering. This allows safe and reliable cooling to be achieved with a minimum of friction and pressure losses caused by the protective layer.
  • the plank on the edge furthest from the direction of rotation is preferably designed as an additional or hybrid plank. If the rotary kiln rotates to the right in the conveying direction, the left edge plank in the conveying direction is "far from the direction of rotation" and designed as an additional or hybrid plank, and vice versa for a rotary kiln rotating to the left, the right edge plank is designed accordingly. In certain designs, it may be sufficient if only this edge plank is designed as an additional or hybrid plank and the other planks are designed as conventional smooth planks. This can improve the prevention of "red river” while also reducing pressure loss across a large area in the other planks.
  • the bulk material is typically made up of particles of different sizes; the larger particles form a coarse fraction, the smaller particles a fine fraction.
  • the additional or hybrid plank is expediently arranged on the lateral edge where the fine fraction occurs in greater abundance. In the case of an upstream rotary kiln, this is usually the side furthest from the direction of rotation, as stated above.
  • at least one immediately adjacent plank is not designed as a hybrid plank, but is provided with a consistently smooth plate covering. To better control the cooling effect on the edge planks, it may be advantageous to provide an additional (separate) ventilation device there.
  • the smooth surface of the planks it is expedient to provide, for example, replaceable grate plates which have a smooth cover plate with cooling gas passage openings, in particular (longitudinal) slots in the conveying direction, for cooling gas to escape.
  • This makes it possible to repair the plank surface in an efficient manner by simply replacing the grate plates if it becomes worn.
  • the slots can be produced efficiently using a casting process for the grate plate, either as transverse slots or as longitudinal slots.
  • the design as a longitudinal slot makes it possible to avoid disturbances in the material bed caused by the slots, in particular parasitic vertical mixing.
  • the longitudinal slots are preferably arranged symmetrically to a center line of the grate plate, which results in a more uniform symmetrical cooling effect.
  • collecting channels extending in the longitudinal direction are expediently arranged at a predetermined distance. They catch material that falls through and ensure that it can be caught again by the cooling gas flow and blown upwards out of the longitudinal slots back into the bulk material.
  • the predetermined distance ensures that a desired cross-sectional width is maintained between the collecting channel and the wall of the grate plate in order to achieve predetermined flow conditions for the cooling gas flow.
  • the collecting channels are advantageously made as a single piece as a cast part with the grate plate, which makes production and maintaining the predetermined distance simpler and more cost-effective. It is advantageous if the grate plates and/or receiving trays are designed as exchangeable modular units for the planks. This enables particularly efficient replacement.
  • a replaceable extension bracket can be provided at the end section of each plank, which forms an extension of the support surface for the bulk material and is not ventilated. This means that no cooling gas is conducted through the extension bracket.
  • the extension bracket thus forms an uncooled end section of the respective plank, from which the (at this point already largely) cooled bulk material slides off and is thus thrown off the cooling grate.
  • the extension brackets preferably do not have a protective layer, but are provided with a smooth plate covering, which can in particular be implemented using grate plates. Since this slipping is particularly wear-intensive due to the abrasive bulk material, this wear occurs on the relatively easily replaceable extension brackets and not on the actual planks, which are thus protected.
  • the extension brackets expediently have an armor plating on their free end. Thermal spraying, spray melting and welding processes are generally used to apply the armor layer. Commonly used materials include cobalt-based alloys (such as tungsten carbide), nickel-based alloys, chromium carbide alloys, etc.
  • the extension brackets are preferably no longer than the length of the initial or final sections, preferably half the length.
  • planks are designed differently when viewed transversely to the conveying direction in terms of their protective coating.
  • planks with an increased coefficient of friction in at least some sections are arranged on at least one of the side edges of the cooling grate, and planks with a consistently smooth surface are arranged in the middle and/or on the other side edge.
  • hybrid planks with their increased coefficient of friction in at least some sections are arranged on at least one of the side edges of the cooling grate, and planks without a protective layer, and therefore with a smooth surface, are arranged in the middle and/or on the other side edge. In this way, an optimal cooling effect can be achieved across the width of the cooling grate by only arranging planks with an increased coefficient of friction, hybrid planks or planks with a continuous protective layer in places identified as critical (particularly near the edge).
  • the invention also expediently includes an arrangement for cooling with several, at least two, cooling grates arranged one behind the other in the conveying direction, each of which has planks.
  • a cooling section is thus formed.
  • the cooling grate at the beginning/end of the cooling section can be designed in the manner described above and is in particular provided with planks, of which at least one is designed as a hybrid plank, as described above, or is provided with a protective layer throughout.
  • at least one further cooling grate (or several), in particular a downstream cooling grate (i.e. in the middle or rear position of the cooling section) can have exclusively smooth planks throughout, with the exception of edge planks, which can be provided with no or at least partially with a protective layer of bulk material.
  • a hybrid structure corresponding to a multi-part hybrid plank can also be functionally realized along the cooling section by means of cooling grates with different planks arranged one behind the other.
  • Fig. 1 is a schematic longitudinal section through a cooling device
  • FIG. 2 schematic partial plan views of a cooling grate of the device in different stages of a conveying movement
  • Fig. 3 is a longitudinal section of a first embodiment of the cooling grate
  • Fig. 4 is an enlarged partial longitudinal section of an initial section of the cooling grate according to Fig. 3;
  • Fig. 5 is an enlarged partial longitudinal section of an initial section of the cooling grate according to Fig. 3;
  • Fig. 6 is an enlarged partial longitudinal section of an initial section of a second embodiment of the cooling grate
  • Fig. 7 shows an enlarged partial longitudinal section of a
  • Fig. 8 is a longitudinal section of a fourth embodiment of the cooling grate;
  • Fig. 9A-F show perspective views of various further embodiments of plank arrangements;
  • Fig. 10A, B each show a cross section through an end region of the plank arrangement according to Fig. 9D and 9E;
  • Fig. 11 shows a partial cross-section of a plank with a smooth surface
  • Fig. 12 shows a partial cross-section of a plank with a protective layer
  • FIG. 13A-C Detailed cross-sections of seals between planks and side walls
  • Fig. 14A, B a perspective view and a plan view of a grate plate
  • Fig. 15 is a longitudinal sectional view along line XV-XV of
  • Fig. 16 is a cross-sectional view along line XVI-XVI of
  • Fig. 17 is a schematic longitudinal section of an arrangement comprising several cooling grates arranged in steps.
  • a schematic embodiment of a cooling device according to the invention is shown in Fig. 1.
  • a housing 1 has a feed shaft 12 in the area of its front wall 11 at one end, at which a discharge opening of an upstream rotary kiln 2 opens.
  • the bulk material to be cooled which is also referred to below as cooling material, is thrown from the rotary kiln 2 and falls into the feed shaft. 12 onto a feed ramp 13 and from there onto a cooling grate 3 designed according to the invention.
  • the feed ramp 13 has a ramp-like shape and extends almost over the entire width of the cooling grate 3 in order to initially ensure that the bulk material 9 is distributed as widely as possible onto the cooling grate 3.
  • the cooling grate 3 is essentially flat (installed horizontally or at an angle) and forms a support surface 30 for the material to be cooled 9 .
  • Cooling gas 80 which is blown into a grate sub-chamber 38 by a cooling air supply 8, is supplied through the cooling grate 3 to the bulk material 9 to be cooled lying on the cooling grate 3.
  • the bulk material 9 is transported from a feed end 31 in the area of the feed ramp 13 in a conveying direction 14 along the support surface 30 to a discharge end 32.
  • the now largely cooled bulk material 9 is guided in a targeted manner to a downstream processing stage, for example a crusher 17, via an optionally provided discharge plate 16.
  • the housing 1 is delimited by a rear wall 18.
  • Side walls 15 are provided along the long sides of the cooling grate 3, so that the cooling grate 3 is completely surrounded by the housing 1.
  • the cooling grate 3 is designed in such a way that it has a plurality of elongated planks 4 arranged parallel in the conveying direction 14. They are mounted on a plurality of grate bearings 36 (by means of bearing rollers) and can be moved individually back and forth over a stroke length 39. They are driven by a drive 37 with a movement control device 37 in such a way that the planks 4 (seen in the conveying direction 14) are pushed forward together (forward stroke) and moved back one after the other (return stroke).
  • the functioning of the cooling grate 3 with its planks 4 is shown schematically in Fig. 2.
  • the grate consists, as already explained, of several elongated planks 4 arranged next to one another, of which three planks 4', 4", 4"' are shown as an example in Fig. 2, which can each represent one or a group of adjacent planks 4.
  • the functional principle which is carried out by the motion control device of the drive 37 is shown with its essential phases in the individual illustrations in Fig. 2.
  • the basic principle is a cyclical sequence of movements in which the planks 4', 4", 4"' move in the conveying direction 14.
  • Fig. 2A) shows a phase of the cycle in which the planks 4 are advanced essentially simultaneously in the conveying direction 14 by one stroke length until they reach their front end position. The next phase is shown in Fig. 2B).
  • planks 4 One of the planks 4, namely plank 4', is retracted by one stroke length until it reaches its rear end position.
  • plank 4"' moves back until it reaches its rear end position.
  • plank 4" also moves to its rear end position, reaching the position shown in Fig. 2D).
  • the cycle then begins again. This creates a movement pattern in which all planks are moved forwards together while they are retracted one after the other.
  • planks 4 take the bed of bulk material 9 lying on them with them.
  • the bulk material 9 lying on the respective plank being moved back cannot follow for the most part because it is held in place by frictional forces exerted on it by the bulk material 9 lying on the adjacent planks or by the side walls 15.
  • the bulk material 9 takes part in the common forward stroke of the planks 4, but in the return stroke of the individual planks not. This is how the conveying effect is created. Even if part of the bulk material is moved during the return stroke, this does not cause any damage, as this only affects a small part and a considerable net conveying effect remains.
  • planks can also be moved in this way if required; however, in the interests of high conveying efficiency, it is generally advantageous to only pull back over a small width, i.e. to pull back the planks individually if possible.
  • speed during the forward movement does not necessarily have to be the same as the speed during the backward movement (return stroke).
  • the planks 4 adjacent to the side walls 15 are moved more slowly than planks arranged in the middle.
  • FIG. 3 A first embodiment of the cooling grate 3 with a plank in longitudinal section is shown in Fig. 3. On the left in the picture you can see the loading ramp 13 on the front wall 11 of the housing 1 of the cooling device.
  • the cooling grate 3 with its planks arranged to move back and forth in the conveying direction 14 is connected to the loading ramp 13. For this purpose, they lie with their guide rail 35 arranged on the underside on bearing rollers of the grate bearings 36.
  • the planks are divided into several sections, namely an initial section 41 located at the beginning as seen in the conveying direction 14, a middle section 42 immediately following this in the conveying direction 14 and a the end section 43 immediately adjacent thereto in the conveying direction 14.
  • the middle section 42 extends over at least half the length of the plank (the length is seen in the conveying direction 14) and thus forms a main section.
  • the initial section 41 and the end section 43 are provided with a protective layer 5 made of bulk material 90 arranged on the plank surface 40.
  • a protective layer 5 made of bulk material 90 arranged on the plank surface 40.
  • receiving troughs 45 are arranged on the upper side of the plank in the initial section 41 and the end section 43.
  • the middle section 42 there is no protective layer 5, but rather a smooth plate covering 6 made in particular of metallic material.
  • the bulk material 9 to be cooled which is applied to the cooling grate 3 by means of the feed ramp 13 and distributed in the conveying direction 14, lies on the plank in the manner already described.
  • this bulk material directly touches the plank surface with its plate covering 6, while in the initial section 41 and the end section 43 there is a protective layer 5 made of bulk material 90.
  • the bulk material 90 is preferably foreign material, e.g. Gravel that is added before commissioning .
  • Such a plank which has at least one of the sections 41, 43 with a protective layer 5 and whose middle section 42 has no such protective layer, but a smooth, in particular metallic plate covering 6, is referred to as a hybrid plank 4*.
  • cooling gas passage openings are provided in the plank for the cooling gas 80 (cooling air).
  • cooling gas passage openings 47 are provided in the area of the starting section 41 and the end section 43 (each with a protective layer 5) and thus guide the cooling gas 80 from the grate sub-space 38 into the respective receiving trough 45.
  • Enlarged partial longitudinal sections for the start and end areas of the hybrid plank 4 * are shown in Fig. 4 and Fig. 5, which also show the design of the plate covering 6 by means of grate plates 7 (see Fig. 14A, B).
  • cooling gas passage openings 48 are provided (only symbolically shown in Fig. 3). In the embodiment shown, they are implemented in the form of longitudinal slots 78 in the grate plates 7 (see Fig. 14A, B), which - as will be explained in more detail later - form the plate covering 6.
  • the cooling gas 80 is guided in a corresponding manner from the grate sub-chamber 38 through the plank through the air passage openings 48 and subsequently enters from below into the material bed 9 formed by the bulk material resting on the plank surface 40.
  • planks can also be connected in whole or in sections to compressed air sources for supplying the cooling gas via flexible supply lines or channels (not shown). This offers the additional advantage of being able to influence the distribution of the cooling gas 80 more precisely. However, this has no influence on the inventive design of the planks with their different surfaces with protective layer 5 / without protective layer and with plate covering 6.
  • the hybrid plank 4 * thus formed therefore has a plank surface 40 which has a different (hybrid) character: in its middle section, which takes up at least half of the total length of the hybrid plank 4 *, there is no Protective layer 5 is not provided, but the surface is formed by a plate covering 6 which is metallically smooth and thus has a low coefficient of friction in relation to the bulk material 9 located above it; in its initial section 41 and its end section 43, however, the plank surface 40 is formed by a protective layer 5 in which the bulk material 90 lies.
  • the protective layer 5 has an irregular, rather rough surface and thus has a (significantly) higher coefficient of friction in relation to the bulk material 9 located above it in comparison with the surface of the plate covering 6.
  • the plate covering 6 is matched in terms of its dimensions, in particular its upper plate surface 60, to the protective layer 5 that occurs during operation, such that the plank surface 40 is essentially the same level over all sections 41, 42, 43.
  • the hybrid plank 4 * just like conventional planks which are provided with a protective layer throughout, has cooling gas passage openings 47, 48 along its entire length, this results in at least an equivalent, if not even improved, supply of cooling gas 80 through the planks of the cooling grate 3 and, moreover, taking into account the reduced undesirable compaction, even an improvement in the cooling effect in the bulk material 9.
  • the end section 43 is designed as described above with a protective layer 5.
  • the starting section 41 can also be designed with a plate covering 6, which is correspondingly provided with cooling gas passage openings 48, while the end section 43 is provided with a protective layer 5 as in the first embodiment.
  • the middle section 42 is still provided with the plate covering 6 according to the invention.
  • Such an embodiment with a different design of the starting section is shown in Fig. 6. - Alternatively, however, in a third embodiment it can be provided that In contrast to the first embodiment described, the end section 43 is designed with a plate covering 6, as shown in Fig. 7.
  • the initial section 41 is provided with a protective layer 5 as in the first embodiment.
  • the middle section 42 is still provided with the plate covering 6 according to the invention.
  • the second or third embodiment can be advantageous. Both have in common that they lead to the reduction in the average coefficient of friction according to the invention.
  • a plate covering 6 is provided in the initial section 41 (as well as in the middle section 42), so that a protective layer 5 is only provided in the end section 43.
  • this embodiment has the special feature that in the area of the discharge end 32 of the cooling grate 3, an extension bracket 49 is arranged on the end section 43 of the respective plank 4*.
  • the extension bracket 49 is provided with a plate covering 6 similar to the end section 43, but unlike the latter, it is not ventilated, i.e. no cooling gas passes through.
  • Fig. 8 Such an embodiment is shown in Fig. 8.
  • an extension bracket 49 can also be provided in a corresponding manner in the other embodiments.
  • the application of the extension bracket 49 is not limited to hybrid planks 4 *, but can also be provided on the other planks, in particular with a continuous protective layer 5 or with a continuous plate covering 6.
  • FIG. 9A to 9G perspective views of various embodiments of plank arrangements for cooling grates 3 are shown. What they all have in common is that the cooling grate 3 is modularly constructed from several modular sections. a start section I, one or more middle sections II and an end section III are provided. These modular sections I, II and III are typically dimensioned so that they are easy to transport and enable an efficient construction of the entire cooling grate. Each modular section I, II and III comprises a certain length of the planks 4 together with the required grate support with bearing rollers 36. For assembly, sections I, II and III are put together one behind the other and the individual lengths of the planks are connected to one another so that a continuous plank is created. Typical dimensions for such sections are, for example:
  • a preferred length for a starting section 41 and/or an end section 43 is, for example, 2.2 m
  • the length of a modular section I, II and III is expediently an integer multiple of this, for example twice, i.e. 4.4 m. This enables an efficient modular construction, so that in the case of 4.4 m long sections I, II and III with only four sections, a cooling grate 3 with a plank length of 17.6 m can be efficiently constructed.
  • the conveying direction in Figs. 9A to 9G is from top left to bottom right. In the area of the feed end 31 located at the top left, an opening 22 of the rotary kiln 2 can be seen.
  • the direction of rotation of the rotary kiln 2 is symbolized by a rotating direction arrow 21. In the embodiments shown, the rotary kiln 2 rotates clockwise in the conveying direction 14.
  • Fig. 9A shows a first embodiment in which hybrid planks 4* according to the first embodiment described above, as shown in Fig. 3, are provided across the entire width of the cooling grate 3.
  • Fig. 9B shows a second embodiment with hybrid planks 4* in which only the end section is provided with a protective layer 5, as in the second embodiment shown in Fig. 6.
  • almost the entire surface of the cooling grate is designed with a smooth, essentially flat plate covering 6, except for the said end section 43 of the planks.
  • this concept of concentrating on the end section 43 is taken to the extreme, in that all the other planks are provided with a plate covering 6 throughout, except for the end section of an edge hybrid plank 4*.
  • the fourth embodiment according to Fig. 9D shows the inverse case to the second embodiment.
  • a protective layer 5 is provided only in the initial section 41 of the hybrid planks 4*, while the remaining areas, namely the middle section 42 and the end section 43, are designed with the plate covering 6.
  • an additional edge plank with a continuous protective layer 5 can be provided as an additional plank 4 * *.
  • the additional plank 4 * * is arranged on the left as seen in the conveying direction 14, i.e. is located at the end furthest from the direction of rotation in relation to the direction of rotation 21. This is the side on which the bulk material 9 emerging from the mouth 22 of the rotary kiln typically has an increased proportion of fine fraction. This therefore accumulates mainly on the plank furthest from the direction of rotation, i.e.
  • planks 4* are designed as hybrid planks 4* as in the fourth embodiment according to Fig. 9D.
  • Fig. 9F A variant of this is shown in Fig. 9F as the sixth embodiment.
  • the protective layer 5 is provided in the end section of the hybrid planks 4* (instead of in the beginning section). It can also be provided that the hybrid planks 4* are provided with the protective layer 5 in both the beginning and the end section.
  • both edge planks are designed as additional planks 4** with a continuous protective layer 5. It should be noted that this variant with additional planks 4** for both edge planks can also be provided in relation to the fifth embodiment according to Fig. 9E, i.e. with the protective layer 5 in the initial section (instead of in the end section) or with the protective layer 5 in the initial and end sections.
  • FIG. 10A and Fig. 10B a cross-sectional view of the cooling grates 3 is shown. These are cross-sections for the plank arrangement according to Fig. 9A and Fig. 9E, respectively, in the area of the middle section 42 (in Fig. 9D and Fig. 9E in the modular sections II) looking in the conveying direction 14.
  • the cooling grate 3, which comprises a total of five planks in the illustrated embodiments, is guided on its two long sides between two edge strips 19, each of which are arranged on one of the side walls 15 (see Fig. 2A).
  • Fig. 10A there are shown five hybrid planks 4 with the plate covering 6 in their respective middle section 42. The spaces between the planks are sealed by longitudinal seals 84.
  • Edge seals 84' are provided for the edge strips 19. These seals 84, 84' prevent an uncontrolled outflow of the cooling gas 80 from the space below the cooling grate 3 upwards into the bed of bulk material 9.
  • Fig. 10B shows the embodiment according to Fig. 9E, which has an additional plank 4** on one side (left in the conveying direction), which is provided with a protective layer 5 throughout. Otherwise, the structure corresponds to that according to Fig. 10A, edge strips 19 are provided on the outer sides and longitudinal seals 84 between the planks and edge seals 84' to the edge strips 19 are provided to seal against uncontrolled outflow of the cooling gas 80.
  • Figs. 11, 12 and 13 show the arrangement of the respective seals 84, 84" in relation to planks with a flat plate covering 6 or with a protective layer 5.
  • Fig. 13A-C are detailed representations of longitudinal seals.
  • the structure of the longitudinal seal 84 between two planks is shown in Fig. 13B and is described below as an example. Also shown there are partial views of a hybrid plank 4* and an additional plank 4**.
  • the type of plank is largely irrelevant for the type of seal 84.
  • On the long sides of each plank there is a vertical wall 46, 46' extending vertically upwards and downwards. It extends upwards so far that the plate surface 60 of the plate covering 6 is approximately level. This also applies to planks for which a protective layer 5 is provided, whereby the level is determined by the height of the protective layer 5 provided for in the design.
  • the seal 84 is designed to seal the gap between the two opposite vertical walls 46 of two adjacent planks against an undesired flow of cooling gas 80.
  • an L-shaped spring plate 86 is arranged on an inner side of the vertical wall 46 facing the center of the plank, which is fastened with its shorter leg to the inner side of the vertical wall 46 in such a way that the longer leg is oriented horizontally approximately parallel to the plate surface 60.
  • Doubled on top of the longer L-leg of the spring plate 86 is an elongated flat sealing plate, the width of which is dimensioned such that it covers the opposite vertical wall 46 of the immediately adjacent plank.
  • the sealing plate 87 rests on a sealing counterpart 88 arranged on the inside of the opposite vertical wall 46, which for this purpose has an extended horizontal sealing surface 89 on its upper side.
  • the sealing effect is that - under the effect of a downward pre-tension of the spring plate 86 - the free end of the sealing plate 87 rests with a downward force on the sealing surface 89 of the sealing counterpart 88.
  • the space between the two opposite vertical walls 46 is sealed on one side by the angled spring plate 86 and on the other side by the sealing plate 87 resting on the sealing surface 89.
  • the spring plate 46, sealing plate 87 and the sealing counterpart 88 each extend continuously over the entire length of a Plank, whereby they can be made up of one or more parts.
  • a cover 85 is provided as mechanical protection for the seal 84 against stresses caused by the bulk material 9 lying on top. This is also L-shaped and its shorter leg is attached to the vertical wall 46 in the same way as the spring plate 86. The longer leg of the cover 85 completely overlaps the sealing plate 87 and rests with its outer end on the edge of the sealing counterpart 88 in order to protect the latter from damage caused by the bulk material 9 lying on top.
  • Fig. 10C the design of a seal 84' can be seen which seals an edge strip 19 from the adjacent edge plank.
  • the spring plate 86 and the cover 85 are arranged on an upwardly projecting angle plate 19' of the edge strip 19, and the sealing counterpart 88 is arranged on the inside of the edge plank.
  • Fig. 10A shows the design of the seal 84" for the other edge strip 19. This is basically a mirror image of the seal 84', so that again the spring plate 86 and the cover 85 are arranged on an upwardly projecting angle plate 19' and the sealing counterpart 88 is arranged on the inside of the edge plank.
  • a grate plate 7, of which the plank covering 6 preferably consists, is shown in a perspective view in Fig. 14A and in a plan view in Fig. 14B.
  • the grate plate 7 has the shape of a flat cuboid.
  • the upper side of the grate plate 7 is smooth and essentially flat, with two spaced apart Fastening holes 76 are arranged countersunk. This serves for the easily detachable fastening of the grate plate 7 on the respective plank 4 * to form the plank covering 6 .
  • a plurality of longitudinal slots 78 are arranged one behind the other. They are elongated and aligned parallel to the center line 78.
  • the longitudinal slots 78 are connected to the underside of the grate plate 7 so that cooling gas 80 can flow through them from a grate sub-chamber 38, through the grate plates 7 and into the bulk material 9 to be cooled lying on the plank 4 * or grate plate 7. This is also shown in Fig. 15 and 16, which each show a longitudinal section through the longitudinal slots 78 and a cross-section through the grate plate 7, respectively.
  • the longitudinal slots 78 can be seen in the longitudinal section, each separated from one another by a separating web 79, as well as a collecting channel 73 arranged underneath and, furthermore, the essentially downwardly open design of the grate plate 7.
  • the cross-section shows that the lower space of the grate plate 7 is symmetrically divided into two areas by a separating web 74 running along the center line.
  • a row of longitudinal slots 78 is arranged in each of the areas. Below this, in each of the two areas, the collecting channel 73 extending over the respective longitudinal slots 78 is arranged. On the one hand, it is designed to catch bulk material 90 falling through the longitudinal slots 78 so that it can be blown out again by the air flow 80.
  • the collecting channel 73 serves to set a predetermined cross-section for the supply of the cooling gas 80 from the grate sub-space 38 to the longitudinal slots 78.
  • the collecting channel 73 thus forms the cooling gas passage openings 48 together with the longitudinal slots 78 in order to ensure a defined passage of cooling gas 80 through the grate plate 7 into the bulk material 9 to be cooled, as shown by the dotted arrows in Fig. 16.
  • Fig. 17 shows a further practical embodiment. It comprises not just one but several cooling grates 3, which are arranged one behind the other in the conveying direction 14 and thus form a cooling section comprising several cooling grates 3, 3', 3". They are preferably arranged in stages as shown in Fig. 17. Due to the staged arrangement, the bulk material 9 passes from the end of one of the cooling grates 3, 3' to the beginning of the respective subsequent cooling grate 3', 3" without further ado. Each of these cooling grates 3, 3', 3" has planks that can be moved over a stroke length 39, as described above. The planks of the various cooling grates can be designed differently in terms of plate covering 6 or protective layer 5.
  • the cooling grate 3' at the middle position of the cooling section has planks that are smooth throughout, i.e. planks with plate covering 6.
  • the cooling grate 3 at the beginning of the cooling section has planks in which at least the initial section is provided with a protective layer 5.
  • the cooling grate 3" at the end of the cooling section has a plate covering 6 or can optionally also be provided with a protective layer 5 at least in its end section.
  • a hybrid structure corresponding to the hybrid planks can also be realized with cooling grates 3, 3', 3" connected in series, whereby in this embodiment it is possible for some or all of the individual cooling grates 3, 3', 3" to be provided uniformly with only one type of plank, either with a protective layer 5 or with a plate covering 6.
  • This enables a rational Production, which can be a significant advantage, especially when creating long cooling sections.

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  • Ceramic Engineering (AREA)
  • Physics & Mathematics (AREA)
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Abstract

L'invention concerne un dispositif de refroidissement de matériau chaud en vrac, en particulier du clinker de ciment, au moyen d'un gaz de refroidissement (80). Une grille de refroidissement (3) transporte une couche du matériau en vrac (9) et est traversée par un gaz de refroidissement. La grille de refroidissement comprend plusieurs barres (4) qui sont déplacées en alternance vers l'avant et vers l'arrière dans la direction de transport et sur lesquelles se trouve le matériau en vrac (9). Des barres adjacentes (4) sont déplacées en même temps pendant le cycle d'avance et à des moments différents pendant le cycle de retour. Selon l'invention, au moins une barre est formée sous la forme d'une barre hybride (4*) avec une configuration variable de la surface de barre (60), ayant une partie centrale (42) avec un revêtement de barre lisse (6) et également une partie de début (41) et/ou une partie de fin (42) comprenant une couche de protection (5) de matériau en vrac (90) située sur la surface de barre (60). Ceci assure une protection contre l'usure. Ceci produit un coefficient de frottement accru pour le matériau en vrac par rapport à la partie centrale. La suppression de la couche de protection dans la partie centrale, qui s'étend sur au moins la moitié de la longueur de la barre hybride, a pour effet de réduire la perte de pression du gaz de refroidissement et de réduire le compactage problématique du matériau en vrac pendant le cycle de retour. Les dépenses d'exploitation sont réduites et l'effet de refroidissement est amélioré.
PCT/EP2024/068726 2023-07-04 2024-07-03 Refroidisseur pour refroidir un matériau chaud en vrac, en particulier du clinker de ciment Pending WO2025008398A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP23183240.3 2023-07-04
EP23183240 2023-07-04

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WO2025008398A1 true WO2025008398A1 (fr) 2025-01-09

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1509737B1 (fr) 2003-05-08 2008-01-09 Claudius Peters Technologies GmbH Procédé pour la refroidissement des matériaux combustibles en vrac
DE102007019530A1 (de) 2007-04-25 2008-10-30 Von Wedel Gmbh & Co. Kg Verfahren und Einrichtung zum Kühlen einer auf einem Förderrost liegenden Schüttgutschicht
DE102010055825B4 (de) 2010-12-23 2013-07-04 Khd Humboldt Wedag Gmbh Verfahren zum Kühlen von heißem Schüttgut und Kühler

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1509737B1 (fr) 2003-05-08 2008-01-09 Claudius Peters Technologies GmbH Procédé pour la refroidissement des matériaux combustibles en vrac
DE102007019530A1 (de) 2007-04-25 2008-10-30 Von Wedel Gmbh & Co. Kg Verfahren und Einrichtung zum Kühlen einer auf einem Förderrost liegenden Schüttgutschicht
DE102010055825B4 (de) 2010-12-23 2013-07-04 Khd Humboldt Wedag Gmbh Verfahren zum Kühlen von heißem Schüttgut und Kühler

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