Material cooler

Abstract

The present invention relates to a material cooler (40), wherein the material cooler (40) has a support surface for a material to be cooled, the material cooler (40) has an application side for introducing a high-temperature material onto the support surface, and an exhaust side for discharging the cooled material, the material cooler (40) has at least a first cooling zone (41) and a second cooling zone (42), the first cooling zone (41) is adjacent to the exhaust side, the first cooling zone (41) has a gas transfer means (51), the second cooling zone (42) is adjacent to the first cooling zone (41), the second cooling zone (42) has a first water supply means (52) for water at a temperature exceeding 100°C, and the first water supply means (52) is located in a material layer positioned below or on the support surface to generate a vapor barrier layer within the material layer.

Description

Technical Field

[0001] The present invention relates to a material cooler that seals a higher temperature partial region with added oxygen against ambient air in a lower temperature partial region of the material cooler.

Background Art

[0002] Plants such as those used to produce clinker are today operated by the "oxy-fuel" method, i.e., ideally with pure oxygen. As a result, the gas at the end of the process is ideally carbon dioxide (which is together with a very easily separable vapor and thus the carbon dioxide concentration at the inlet to the downstream carbon dioxide separation device does not decrease). Thereby, carbon dioxide can be easily separated, so that emissions can be avoided. In particular, this eliminates the particularly expensive separation of nitrogen. However, as a result, the possibility of an additional air supply source, i.e., ambient air entering the system, should be avoided as much as possible.

[0003] Generally, there is a conventional separation point between the oxygen-containing region and the ambient air in the material cooler, and at least finally cooling is performed by the ambient air.

[0004] German Patent Application Publication No. 102006026234 discloses an apparatus and method for cooling a bulk material.

[0005] International Publication No. 2022248384 discloses a method and apparatus for producing cement clinker.

[0006] U.S. Patent No. 11621168 discloses a method and apparatus for doping a semiconductor material.

[0007] U.S. Patent No. 8850831 discloses a method for cooling a solid granular material.

[0008] German Patent Application Publication No. 2158317 discloses a combustion apparatus for burning ore pellets and similar objects.

[0009] U.S. Patent No. 5,775,891 discloses a grid cooler for combustion materials and a method therefor.

[0010] German Patent Application Publication No. 2404086 discloses a method and apparatus for cooling granular materials. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] German Patent Application Publication No. 102006026234 Specification [Patent Document 2] International Publication No. 2022248384 [Patent Document 3] U.S. Patent No. 11621168 [Patent Document 4] U.S. Patent No. 8850831 [Patent Document 5] German Patent Application Publication No. 2158317 [Patent Document 6] U.S. Patent No. 5775891 [Patent Document 7] German Patent Application Publication No. 2404086 [Overview of the project]

[0012] A conventional method to avoid undesirable mixing, and therefore the entry of the wrong air, is to use separation plates or baffles, for example, within a material cooler, to minimize gas flow between different regions. These measures are effective above the material bed and thus reduce mixing. However, these measures are ineffective within the material bed where gas mixing can occur. Nevertheless, this still results in mixing, and therefore, on the one hand, the loss of valuable oxygen and on the other hand, the entry of nitrogen into the interior. Furthermore, such static equipment exhibits wear and tear.

[0013] The objective of this invention is to minimize further air intrusion into the system via the material cooler.

[0014] This objective is achieved by a material cooler having the features described in claim 1 and a method having the features described in claim 10. Advantageous further developments will become apparent from the dependent claims, the following description and drawings.

[0015] The material cooler according to the present invention is used to cool heat-treated materials, particularly bulk materials, such as clinker. The actual heat treatment process is preferably carried out by an oxygen-fueled process, i.e., in an oxygen-enriched atmosphere. The material cooler has a support surface for the material to be cooled. The material to be cooled moves along the support surface through the material cooler. This can be achieved actively by a transport element or passively, for example, by an inclined configuration. The material cooler has a filling side for introducing the hot material onto the support surface and a discharge side for discharging the cooled material. The material cooler has at least one first cooling zone and at least one second cooling zone. The first cooling zone is adjacent to the discharge side. Thus, the cooled material is discharged from the first cooling zone. The first cooling zone has a gas supply line. The gas supply line is preferably used, as an example, to supply ambient air to cool the material and can therefore be handled after being removed from the material cooler. The gas supply line can also be used to supply gas from, for example, a circuit. The gas supplied via the gas supply line generally contains interfering gas components, particularly nitrogen. The second cooling zone is adjacent to the first cooling zone. Therefore, the second cooling zone is positioned ahead of the first cooling zone along the material flow.

[0016] According to the present invention, the second cooling zone has a first water supply line for water above 100°C. The first water supply line is located within the material layer, either below or above the support surface. This helps to create a vapor barrier layer within the material layer. In this case, the first water supply line can be designed for pressurized liquid hot water or steam. A supply above 100°C is advantageous for preventing condensation in the material. The material to be cooled, e.g., clinker, may react with water, so wetting must be avoided. This is necessary to prevent subsequent undesirable reactions of the product, e.g., clinker, during storage. The water is preferably supplied at 100-200°C. Here, the optimal conditions between the utilization of thermal energy and the avoidance of condensation must be selected. For example, direct cooling of the material layer from above by water spraying is known. However, the disadvantage here is that water in gaseous form is formed only on top of the material layer, and water flows from below through the material layer for cooling. Thus, water sprayed from above has no effect other than that of a separation plate or baffle. Furthermore, there is an increased risk of localized and concentrated cooling of the material, leading to water absorption and thus undesirable reactions during storage. However, the essential element in the present invention is the application of water beneath or within the material layer, and as a result, the barrier effect is actually achieved not only directly above the material layer but also within the material layer.

[0017] One important feature is the supply of water from below. Top-down applications, such as spraying, are known. However, in these cases, a gas layer not occupied by the vapor always remains within the material. A supply from below ensures that a flow exists through the material layer, and therefore an efficient gas barrier exists in this region, and indeed within the material itself.

[0018] Depending on the type of first water supply line, either from below the support surface or from within the material layer positioned on the support surface, the device features the direct effect of generating a vapor barrier layer within the material layer during operation. Furthermore, the first water supply line must be suitable for transporting steam or water under pressure and at temperatures above 100°C. In the case of steam, the volume in which the flow exists is significantly large, and in the case of liquid water, the pressure is significantly high. In addition, condensation in the first water supply line must be prevented to ensure that liquid water below 100°C is not transported into the material layer.

[0019] Therefore, the effects produced in this method are a direct result of the structural means of the material cooler.

[0020] The advantage of using steam is that water can be removed from the exhaust gas flow particularly easily through condensation. Therefore, carbon dioxide separation systems for use and storage, and thus for achieving climate neutrality, become easier to implement overall.

[0021] For the introduction of steam from below and the generation of a steam barrier layer within the material layer, the steam barrier layer is also formed above the material layer, and thus separation can also be performed here, which can be further facilitated by a separation plate or the like, as is known from the prior art. In the present invention, in addition to this known steam barrier layer above the material layer, it is essential that the steam barrier layer is automatically generated within the material layer by the apparatus, thus ensuring that the unwanted supply of wrong air through the material layer is prevented.

[0022] In another embodiment of the present invention, the material cooler has a third cooling zone. The third cooling zone is adjacent to the second cooling zone. The third cooling zone is designed for operation with oxygen-enriched air having an oxygen content of more than 50% by volume, preferably more than 90% by volume, i.e., for an "oxy-fuel" process. This means that the material cooler is equipped to operate in a manner well known to those skilled in the art. For example, this applies to selecting materials that must be resistant to an oxygen-enriched atmosphere, as is well known to those skilled in the art. Further, as is also well known to those skilled in the art, this applies to sealing against the surroundings to avoid unwanted ingress of incorrect air and thus nitrogen. Thus, as part of the routine considerations in the art, the device must be designed to operate in such an atmosphere.

[0023] Alternatively, the oxygen-enriched atmosphere can also be present only within the material cooler and thus in devices adjacent to the second cooling zone, such as within the kiln head. In this case, the sealing is carried out directly at the discharge side of the material cooler.

[0024] In another embodiment of the present invention, the second zone extends over at least 2%, preferably at least 3%, of the total length of the material cooler.

[0025] In another embodiment of the present invention, the second zone extends over a maximum of 50%, preferably a maximum of 35%, more preferably a maximum of 20%, and even more preferably a maximum of 10% of the total length of the material cooler.

[0026] In another embodiment of the present invention, the material cooler has a third cooling zone. The third cooling zone is adjacent to the second cooling zone. The third cooling zone is designed to operate with a mixture of carbon dioxide and oxygen, where the sum of oxygen and carbon dioxide exceeds 80% by volume. This also corresponds to an oxygen-fueled method in which carbon dioxide (generally from exhaust gases) is further fed back. In this way, nitrogen, which is not present in pure oxygen, is replaced, and thus the gas flow is increased to make the gas flow transport capacity comparable to that of conventional methods. Thus, for example, it is possible to select an oxygen-to-carbon dioxide ratio that corresponds to 1:5, similar to the oxygen content in air, taking into account other gas components. This means that the material cooler is equipped to operate in a manner well known to those skilled in the art. For example, this applies to selecting materials that must be resistant to oxygen-enriched and / or carbon dioxide-enriched atmospheres, as is well known to those skilled in the art. Furthermore, as is also well known to those skilled in the art, this applies to sealing to the surroundings in order to avoid the unwanted intrusion of wrong air, and therefore nitrogen. Thus, as part of the routine considerations in the art, the apparatus must be designed to operate in such atmospheres.

[0027] In another embodiment of the present invention, the material cooler has a fourth cooling zone. The fourth cooling zone is adjacent to the second cooling zone. The fourth cooling zone has a carbon dioxide supply section. In particular, carbon dioxide can be supplied to the cauldron, for example, via a carbon dioxide outlet and a tertiary line. In addition, or alternatively, the carbon dioxide outlet can be connected to the carbon dioxide supply section, i.e., carbon dioxide can be recirculated. Therefore, the carbon dioxide does not have to be pure carbon dioxide, but may contain additional substances, especially in the case of recirculated carbon dioxide. The objective is to achieve a double barrier layer consisting of steam on the one hand and (recirculated) carbon dioxide on the other. Therefore, the apparatus is designed to be able to carry these atmospheres or to be stable in these atmospheres.

[0028] In another embodiment of the present invention, the material cooler has a fifth cooling zone. The fifth cooling zone is adjacent to the fourth cooling zone. The fifth cooling zone has a second feed line for water above 100°C. The second feed line is located within the material layer, either below or above the support surface, to generate a vapor barrier layer within the material layer. In this case, the second feed line can be designed for pressurized liquid water or vapor. A supply above 100°C is advantageous for preventing condensation in the material. This is necessary to prevent subsequent undesirable reactions during storage of the product, e.g., clinker. The water is preferably supplied at 200-400°C. Due to the presence of the subsequent cooling zone, water at considerably higher temperatures can be used here. The points mentioned above also apply here. The second vapor barrier layer makes it possible to obtain relatively clean secondary and tertiary air, in particular. Here again, due to spatial characteristics, the apparatus is precisely designed to form and support these different zones, and therefore different atmospheres.

[0029] In another embodiment of the present invention, the material cooler has a seventh cooling zone. The seventh cooling zone is adjacent to the fourth cooling zone. The seventh cooling zone is designed for operation in oxygen-enriched environments having an oxygen content of more than 50% by volume, preferably more than 90% by volume. This means that the material cooler is equipped to operate in a manner well known to those skilled in the art. For example, this means selecting materials that must be resistant to oxygen-enriched atmospheres, as well as well known to those skilled in the art. Furthermore, this means sealing to the surroundings to avoid the undesirable intrusion of the wrong air, and therefore nitrogen, as is also well known to those skilled in the art. Thus, as part of routine considerations in the art, the apparatus must be designed to operate in such atmospheres.

[0030] In another embodiment of the present invention, the material cooler has a sixth cooling zone. The sixth cooling zone is adjacent to the fifth cooling zone. The sixth cooling zone is designed for operation in oxygen-enriched environments having an oxygen content of more than 50% by volume, preferably more than 90% by volume. This means that the material cooler is equipped to operate in a manner well known to those skilled in the art. For example, this means selecting materials that must be resistant to oxygen-enriched atmospheres, as well as well known to those skilled in the art. Furthermore, this means sealing to the surroundings to avoid the undesirable intrusion of the wrong air, and therefore nitrogen, as is also well known to those skilled in the art. Thus, as part of routine considerations in the art, the apparatus must be designed to operate in such atmospheres.

[0031] In another embodiment of the present invention, the third cooling zone has a gas outlet. The gas outlet is connected to a carbon dioxide supply unit and / or a cauldron, particularly via a tertiary air line.

[0032] In another embodiment of the present invention, a first mechanical gas separator is positioned between a first cooling zone and a second cooling zone. In this case, it is preferable that the first mechanical gas separator is at a sufficient distance from the material on the support surface to prevent wear. Similarly, further mechanical gas separators may be positioned between further cooling zones.

[0033] Naturally, embodiments of the present invention can be combined with prior art separation plates or baffles. Undesirable mixing is, of course, further reduced by this.

[0034] In another aspect, the present invention relates to a method for operating a material cooler according to the present invention. A filling atmosphere is applied to the filling side, and an exhaust atmosphere is applied to the exhaust side. The filling atmosphere and the exhaust atmosphere are different. The exhaust atmosphere is preferably ambient air or formed by ambient air, preferably differing only in humidity and possibly dust from the ambient air. The filling atmosphere preferably has a reduced nitrogen content compared to the exhaust atmosphere. The filling atmosphere and the exhaust atmosphere are separated by a vapor barrier layer in the material being cooled in the second cooling zone. In contrast to nitrogen, vapor is very easily separated from carbon dioxide, and therefore the technical and energy consumption for purifying carbon dioxide can be dramatically reduced with respect to the sequestration of carbon dioxide after the process, and thus with respect to the prevention of carbon emissions into the external environment as required for climate neutrality. At the same time, undesirable emissions of carbon dioxide are also prevented.

[0035] In another embodiment of the present invention, the filling atmosphere has a higher oxygen content and a lower nitrogen content than the exhaust atmosphere.

[0036] In another embodiment of the present invention, the second cooling zone is non-condensable, i.e., at a temperature level above 100°C under atmospheric pressure or following a vapor pressure curve at other pressures. As a result, water remains in the gas phase as vapor and does not condense on the material. This ensures that wetting and therefore condensation during storage are avoided.

[0037] All the features described in relation to the apparatus can, of course, be applied to this method as well.

[0038] The material cooler according to the present invention will be described in more detail below with reference to exemplary embodiments shown in the drawings. [Brief explanation of the drawing]

[0039] [Figure 1] Example 1 [Figure 2] Second example [Figure 3] Third example [Figure 4] Fourth example [Figure 5] Fifth example [Figure 6] Example 6 [Modes for carrying out the invention]

[0040] Figure 1 shows a first example, which is, for example, a plant for producing clinker from limestone. The plant has a preheater 10, a calcinerator 20, a rotary kiln 30, and a material cooler 40 according to the present invention, and the material flow is carried from the preheater 10 through the calcinerator 20 and the rotary kiln 30 to the material cooler 40. The gas flow enters the preheater from the rotary kiln 30 through the calcinerator 20. The rotary kiln 30, the calcinerator 20, and the preheater 10 are designed to operate on an oxygen fuel method, i.e., (technically) pure oxygen, and operate in this manner. The material cooler has a first cooling zone 41 that cools the material, the clinker described above, to near ambient temperature, supplied with cold ambient air by a gas supply line 51. Therefore, in order to separate the oxygen-enriched region from the ambient air, the material cooler has a second cooling zone 42 to which water under pressure, for example, 150°C, is supplied from below via a first water supply line 52, thereby creating a reliable, simple, and wear-free separation between the oxygen-enriched region and the ambient air.

[0041] In this respect, all the examples described below are the same.

[0042] The first example involves supplying oxygen directly to the rotary kiln 30, for example, via the kiln head. Since combustion in (technically) pure oxygen is at a very high temperature, it is possible to eliminate the need for oxygen preheating.

[0043] Figure 2 shows a second example in which, unlike the first example, oxygen is not directly injected into the rotary kiln 30, but is first sent to the third cooling zone 43 via the oxygen supply unit 53, where it is preheated, and then transported from the third cooling zone 43 to the rotary kiln. The third cooling zone 43 is located directly adjacent to the second cooling zone 42.

[0044] Figure 3 shows a third example in which the fourth cooling zone 44 is located adjacent to the second cooling zone 42. Carbon dioxide is supplied to the fourth cooling zone 44 via the carbon dioxide supply unit 54. Oxygen in the third example is also supplied directly to the rotary kiln 30, as in the first example.

[0045] The fourth example shown in Figure 4 differs from the third example in that a fifth cooling zone 45, having a second water supply line 55, is located adjacent to the fourth cooling zone 44. This prevents carbon dioxide from entering the rotary kiln 30 from the fourth cooling zone 44. Conversely, carbon dioxide is supplied directly to the calcinerator 20 via a tertiary air line to generate a larger volume flow there and thus increase the material gas flow transport capacity.

[0046] The fifth example shown in Figure 5 differs from the third example in that the seventh cooling zone 47 is located adjacent to the fourth cooling zone 44, and (technically) pure oxygen is supplied to the seventh cooling zone 47 via the oxygen supply unit 57, where it is preheated before being supplied to the rotary kiln 30. In the fourth example, carbon dioxide from the fourth cooling zone 44 is supplied to the calcinerator 20 via a tertiary air line.

[0047] The sixth example shown in Figure 6 differs from the fourth example in that the material cooler 40 has a sixth cooling zone 46 adjacent to the fifth cooling zone 45, and (technically) pure oxygen is supplied to the sixth cooling zone 46 via an oxygen supply unit 56, where it is preheated before being supplied to the rotary kiln 30. [Explanation of symbols]

[0048] 10 Preheater 20 grills 30 Rotary Kilns 40 Material cooler 41. First Cooling Zone 42. Second Cooling Zone 43. Third Cooling Zone 44. Fourth Cooling Zone 45. Fifth Cooling Zone 46. ​​The sixth cooling zone 47. The 7th Cooling Zone 51 Gas supply line 52. First water supply line 53 Oxygen Supply Unit 54 Carbon Dioxide Supply Department 55 Second water supply line 56 Oxygen supply unit 57 Oxygen Supply Unit

Claims

1. A material cooler (40), wherein the material cooler (40) has a support surface for a material to be cooled, the material cooler (40) has a filling side for introducing a high-temperature material onto the support surface, and a discharge side for discharging the cooled material, the material cooler (40) has at least one first cooling zone (41) and at least one second cooling zone (42), the first cooling zone (41) is adjacent to the discharge side, the first cooling zone (41) has a gas supply line (51), the second cooling zone (42) is adjacent to the first cooling zone (41), the second cooling zone (42) has a first water supply line (52) for water exceeding 100°C, and the first water supply line (52) is located within the material layer, positioned below or on the support surface to generate a vapor barrier layer within the material layer.

2. The material cooler (40) according to claim 1, characterized in that the material cooler (40) has a third cooling zone (43), the third cooling zone (43) is adjacent to the second cooling zone (42), and the third cooling zone (43) is designed to operate with enriched oxygen having an oxygen content of more than 50% by volume, preferably more than 90% by volume.

3. The material cooler (40) according to claim 1, wherein the material cooler (40) has a third cooling zone (43), the third cooling zone (43) is adjacent to the second cooling zone (42), and the third cooling zone (43) is designed to operate with a mixture of carbon dioxide and oxygen, the sum of oxygen and carbon dioxide exceeds 80% by volume.

4. The material cooler (40) according to claim 1, characterized in that the material cooler (40) has a fourth cooling zone (44), the fourth cooling zone (44) is adjacent to the second cooling zone (42), and the fourth cooling zone (44) has a carbon dioxide supply unit (54).

5. The material cooler (40) according to claim 4, characterized in that the material cooler (40) has a fifth cooling zone (45), the fifth cooling zone (45) is adjacent to the fourth cooling zone (44), the fifth cooling zone (45) has a second water supply line (55) for water exceeding 100°C, and the second water supply line (55) is located within the material layer, positioned below or on the support surface, in order to generate a vapor barrier layer within the material layer.

6. The material cooler (40) according to claim 5, characterized in that the material cooler (40) has a seventh cooling zone (47), the seventh cooling zone (47) is adjacent to the fourth cooling zone (44), and the seventh cooling zone (47) is designed to operate with enriched oxygen having an oxygen content of more than 50% by volume, preferably more than 90% by volume.

7. The material cooler (40) according to claim 5, characterized in that the material cooler (40) has a sixth cooling zone (46), the sixth cooling zone (46) is adjacent to the fifth cooling zone (45), and the sixth cooling zone (46) is designed to operate with enriched oxygen having an oxygen content of more than 50% by volume, preferably more than 90% by volume.

8. The material cooler (40) according to any one of claims 2 to 7, characterized in that the third cooling zone (43) has a gas outlet, and the gas outlet is connected to the carbon dioxide supply unit (54) and / or the roaster.

9. A material cooler (40) according to any one of claims 1 to 8, characterized in that a first mechanical gas separator is positioned between the first cooling zone (41) and the second cooling zone (42).

10. A method for operating a material cooler (40) according to any one of claims 1 to 9, wherein a filling atmosphere is applied to the filling side, a discharge atmosphere is applied to the discharge side, and the filling atmosphere and the discharge atmosphere are separated by a vapor barrier layer in the material being cooled in the second cooling zone (42).

11. The method according to claim 10, characterized in that the filling atmosphere has a higher oxygen content and a lower nitrogen content than the discharge atmosphere.

12. The method according to one of claims 10 to 11, characterized in that the second cooling zone (42) is non-condensing, ensuring that the water remains in the gas phase as vapor.

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