preheater

Abstract

To provide a preheater for uniformly dispersing a cement raw material in a gas in a duct.SOLUTION: The preheater includes a cyclone that separates the heat-exchanged gas and the cement raw materials, a duct D2 that guides the gas and the cement raw materials to the cyclone, a chute D2 having a charging port A3 through which the cement raw materials are charged into the duct S3, and a dispersion plate 6 that is located at the charging port A3 of the chute S3, extends from the inside of the chute S3 toward the duct D2, and disperses the cement raw materials charged into the duct D2. The dispersion plate 6 has a side blade 11 positioned on the outside in the widthwise direction and a center blade 10 positioned closer to the center in the widthwise direction than the side blade 11 and having an elevation angle θ 1 with respect to a plane H1 orthogonal to the axis line LC of the duct D2 larger than the elevation angle θ 2 of the side blade 11.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present specification discloses a cement raw material preheater. [Background technology]

[0002] In cement production, cement raw materials are preheated by heat exchange with high-temperature gas. Dispersing the cement raw materials in the high-temperature gas effectively preheats the cement raw materials. A raw material charging device for dispersing cement raw materials in gas in this manner is disclosed in JP 2020-193116 A.

[0003] This raw material charging device is equipped with a distributor plate that distributes the cement raw materials in the gas. The upper surface of this distributor plate is formed in an overall upward convex shape, and the width of the upper surface of the distributor plate gradually increases toward the downstream side in the charging direction. This distributor plate efficiently distributes the cement raw materials. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2020-193116 Summary of the Invention [Problem to be solved by the invention]

[0005] Even if the cement raw materials are dispersed using the dispersion plate of the raw material charging device disclosed in JP 2020-193116 A, it is not easy to uniformly disperse the cement raw materials in the gas inside the duct.

[0006] It is Applicant's intent to provide a preheater that uniformly distributes cement ingredients in the gas within the duct. [Means for solving the problem]

[0007] The preheater disclosed in this specification comprises: A cyclone that separates the heat-exchanged gas from the cement raw materials; a duct for introducing the gas and the raw material into the cyclone; a chute having an inlet for introducing the raw material into the duct; and, a dispersion plate located at the inlet of the chute, extending from inside the chute toward the duct, for dispersing the raw material introduced into the duct; The dispersion plate has side blades located on the outer sides in the width direction, and a center blade located more centrally in the width direction than the side blades and having an elevation angle with respect to a plane perpendicular to the axis of the duct larger than that of the side blades. [Effects of the Invention]

[0008] The preheater can uniformly distribute the cement ingredients in the gas within the duct. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic configuration diagram of cement burning equipment including a preheater according to one embodiment. [Figure 2] FIG. 2 is a side cross-sectional view showing the duct, chute and dispersion plate of the preheater of FIG. 1 in use. [Figure 3] FIG. 3 is a plan cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a partial side view seen in the direction of arrow IV in FIG. [Figure 5] 5 is a side cross-sectional view showing another state of use of the duct and chute in the use state of FIG. 2 and the dispersion plate whose rotation position is changed from that in the use state of FIG. 2. FIG. [Figure 6] FIG. 6 is a plan cross-sectional view showing the use of a duct, a chute, and a dispersion plate provided in a preheater according to another embodiment. [Figure 7] 7A is a side cross-sectional view of the center blade of the dispersion plate taken along line VIIA-VIIA in FIG. 6, and FIG. 7B is a side cross-sectional view of the side blade of the dispersion plate taken along line VIIB-VIIB in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments will be described in detail below with reference to the drawings as appropriate.

[0011] 1 shows a schematic configuration of cement calcination equipment 1. Cement calcination equipment 1 includes a preheater 2 that preheats cement raw materials, a calciner 3 that calcines the preheated cement raw materials, and a calciner 4 that calcines the calcined cement raw materials. Cement calcination equipment 1 also includes an exhaust duct 5 that can exhaust gas from preheater 2.

[0012] In this cement calcination facility 1, cement raw materials are fed into a preheater 2, and then sent from the preheater 2 to a calciner 3 and a calciner 4. Gases heated in the calciner 3 and the calciner 4 pass through the preheater 2 and are exhausted from an exhaust duct 5.

[0013] The preheater 2 includes cyclones C1 to C5 connected in series from upstream to downstream in the gas flow. The cement raw materials are powder and granular material, and cyclone C1 generates a swirling flow in the gas in which the cement raw materials have been dispersed, thereby separating the cement raw materials from the gas. Cyclone C1 is capable of discharging the separated cement raw materials downward and discharging the separated gas upward. Like cyclone C1, cyclones C2 to C4 are also capable of separating the cement raw materials from the gas, discharging the cement raw materials downward, and discharging the gas upward.

[0014] The preheater 2 includes a duct D1 connecting the calciner 3 and the cyclone C1. The preheater 2 includes a duct D2 connecting the cyclone C1 and the cyclone C2. Similarly, the preheater 2 includes a duct D3 connecting the cyclone C2 and the cyclone C3, a duct D4 connecting the cyclone C3 and the cyclone C4, and a duct D5 connecting the cyclone C4 and the cyclone C5.

[0015] The preheater 2 is equipped with a calciner chute S1 that feeds the cement raw materials discharged from cyclone C1 into calciner 4. The preheater 2 is equipped with a calciner chute S2 that feeds the cement raw materials discharged from cyclone C2 into calciner 3. The preheater 2 is equipped with a chute S3 that feeds the cement raw materials discharged from cyclone C3 into duct D2, a chute S4 that feeds the cement raw materials discharged from cyclone C4 into duct D3, and a chute S5 that feeds the cement raw materials discharged from cyclone C5 into duct D4. The preheater 2 is further equipped with a chute S6 that feeds the cement raw materials into duct D5. Note that the preheater 2 is equipped with five cyclones, but the number of cyclone stages provided in the preheater 2 is not particularly limited.

[0016] The dotted arrows in Figure 1 indicate the flow of gas. Gases heated in the calciner 4 and the calciner 3 rise and are guided from the calciner 4 and the calciner 3 to cyclone C1 through duct D1. The gas from cyclone C1 is guided to cyclone C2 through duct D2. The gas from cyclone C2 is guided to cyclone C3 through duct D3. The gas from cyclone C3 is guided to cyclone C4 through duct D4, and the gas from cyclone C4 is guided to cyclone C5 through duct D5. The gas from cyclone C5 is discharged through exhaust duct 5.

[0017] The solid arrows in Figure 1 represent the flow of cement raw materials. The cement raw materials are fed into preheater 2 through chute S6. The cement raw materials fed into duct D5 through chute S6 are then guided to cyclone C5 together with gas. The cement raw materials separated from the gas in cyclone C5 are fed into duct D4 through chute S5. The cement raw materials fed into duct D4 are then guided to cyclone C4 together with gas. The cement raw materials separated from the gas in cyclone C4 are fed into duct D3 through chute S4. The cement raw materials fed into duct D3 are then guided to cyclone C3 together with gas. The cement raw materials separated from the gas in cyclone C3 are fed into duct D2 through chute S3. The cement raw materials fed into duct D2 are then guided to cyclone C2 together with gas, and the cement raw materials separated from the gas in cyclone C2 are fed into calciner 3 through calciner chute S2. The cement raw materials fed into the calciner 3 are introduced into the cyclone C1 together with the gas. The cement raw materials separated from the gas in the cyclone C1 are fed into the calciner 4 via the calciner chute S1.

[0018] This preheater 2 can diffuse the cement raw materials into the gas and preheat the cement raw materials with the gas.

[0019] Figure 2 shows a cross section of the connection between duct D2 and chute S3 shown in Figure 1. This cross section is taken along the axis LC of duct D2. As shown in Figure 2, chute S3 has an inlet A3 that opens into duct D2.

[0020] The preheater 2 includes a distribution plate 6 located at the inlet A3 of the chute S3, a shaft 7 to which the distribution plate 6 is attached and which is supported by the chute S3, and a handle 8 fixed to the shaft 7. The shaft 7 is rotatable relative to the chute S3. By rotating the handle 8, the shaft 7 and the distribution plate 6 can be rotated relative to the chute S3. The shaft 7 is not limited to a rotatable shaft, but may also be a fixed shaft that does not rotate.

[0021] The dispersion plate 6 extends from inside the chute S3 toward the duct D2. The dispersion plate 6 has a center blade 10, side blades 11, and a partition wall 12. The tip of the dispersion plate 6 is located inside the duct D2. However, the tip of the dispersion plate 6 may be located outside the duct D2.

[0022] The center vane 10 extends from within the chute S3 toward the duct D2. The center vane 10 has a plane 10A extending from within the chute S3 toward the duct D2. The double-headed arrow L1 indicates the length of the center vane 10. This length L1 is the length of the plane 10A. The two-dot chain line H1 indicates a plane perpendicular to the axis LC of the duct D2. The double-headed arrow θ1 indicates the elevation angle of the center vane 10 relative to the plane H1. This elevation angle θ1 is the inclination angle of the plane 10A.

[0023] The side blade 11 extends from within the chute S3 toward the duct D2. The side blade 11 has a plane 11A extending from within the chute S3 toward the duct D2. The double-headed arrow L2 indicates the length of the side blade 11. The two-dot chain line H2 indicates a plane perpendicular to the axis LC of the duct D2. The double-headed arrow θ2 indicates the elevation angle of the side blade 11 relative to the plane H2. This elevation angle θ1 is the inclination angle of the plane 11A.

[0024] In this dispersion plate 6, the elevation angle θ1 of the center blade 10 is larger than the elevation angle θ2 of the side blades 11. The length L1 of the center blade 10 is larger than the length L2 of the side blades 11. Note that in the dispersion plate 6, the length L1 of the center blade 10 and the length L2 of the side blades 11 may be the same, or the length L1 may be shorter than the length L2.

[0025] The partition wall 12 protrudes upward from the flat surface 10A of the center blade 10. The partition wall 12 extends along the flat surface 10A from inside the chute S3 toward the duct D2. The partition wall 12 extends to the tip of the center blade 10.

[0026] FIG. 3 shows the dispersion plate 6 along with a cross section of the duct D2 and the chute S3 taken along line III-III in FIG. 2. FIG. 2 is a cross section taken along line II-II in FIG. 3. As shown in FIG. 3, the dispersion plate 6 has a pair of side blades 11. In the width direction of the dispersion plate 6, the side blades 11 are located on the outer sides, and the center blade 10 is located more centrally than the side blades 11. The center blade 10 extends toward the center of the duct D2 in the radial direction of the duct D2. The tip of the center blade 10 is located more inward in the duct D2 than the tips of the side blades 11. The dispersion plate 6 has a pair of partition walls 12. Each partition wall 12 is located at the width direction end of the center blade 10 and extends from within the chute S3 toward the duct D2.

[0027] 4 shows a portion of the side of the chute S3 as viewed in the direction of arrow IV in FIG. 3. This preheater 2 is equipped with a positioning device 13 that can fix the rotational position of the dispersion plate 6. The handle 8 has a through hole 8A. The positioning device 13 has a plate 13B with a plurality of positioning holes 13A and a pin 13C that is inserted into the through holes 8A and the positioning holes 13A of the handle 8. By inserting this pin 13C into the through holes 8A and the positioning holes 13A, the positioning device 13 can fix the rotational position of the dispersion plate 6. Note that the positioning device 13 is not limited to having positioning holes 13A and pins 13C, as long as it can fix the rotational position of the dispersion plate 6.

[0028] Figure 5 shows a usage state in which the rotation position of the dispersion plate 6 is different from that shown in Figure 2. In the usage state of Figure 5, the elevation angle θ1 of the center blade 10 and the elevation angle θ2 of the side blade 11 are smaller than in the usage state of Figure 2. In the usage state of Figure 5, the dispersion plate 6 is fixed by the positioning member 13 at a rotation position of the dispersion plate 6 that is different from that in the usage state shown in Figure 2.

[0029] In this preheater 2, the elevation angle θ1 of the center blade 10 is larger than the elevation angle θ2 of the side blades 11 of the dispersion plate 6. As a result, the charging speed of the cement raw materials at the center blade 10 is fast and the charging speed of the cement raw materials at the side blades 11 is slow.

[0030] The gas flow velocity at the radial center of the duct D2 is faster than the gas flow velocity at the radial outer side of the duct D2. The center blade 10 can increase the charging speed of the cement raw materials charged into the radial center of the duct D2. By charging the cement raw materials using the center blade 10, the cement raw materials can easily reach the radial center of the duct D2. Furthermore, the gas flow velocity at the radial outer side of the duct D2 is slower than the gas flow velocity at the radial center of the duct D2. The side blades 11 can slow the charging speed of the cement raw materials charged into the radial outer side of the duct D2. This prevents the cement raw materials from falling from the duct D2 to the cyclone C1 at the radial outer side of the duct D2 due to an excessively fast charging speed. This preheater 2 can charge the cement raw materials while distributing them throughout the radial direction of the duct D2. This preheater 2 can improve the efficiency of heat exchange between the gas and the cement raw materials by dispersing the cement raw materials over the entire radial direction of the duct D2.

[0031] The center blade 10 can increase the charging speed of the cement raw materials charged into the radial center of the duct D2 where the gas flow speed is high. The cement raw materials charged at a high speed reach further upstream in the gas flow direction than the cement raw materials charged at a low speed. This preheater 2 can extend the heat exchange time between the cement raw materials and the gas at the radial center of the duct D2 where the gas flow speed is high. This preheater 2 can improve the efficiency of heat exchange between the gas and the cement raw materials.

[0032] The cyclone C2 is connected to the cyclone C1 via the duct D2. The cyclone C1 is a pre-cyclone located upstream of the cyclone C2 in the gas flow direction. The distributor plate 6 increases the charging speed of the cement raw materials charged into the radial center of the duct D2 by the center blade 10, while decreasing the charging speed of the cement raw materials charged into the radial outer side of the duct D2 by the side blades 11. This allows the cement raw materials to reach the radial center of the duct D2, while preventing the cement raw materials charged into the radial outer side of the duct D2 from falling from the duct D2 to the cyclone C1. The distributor plate 6 is suitable for charging the cement raw materials into the duct D2 connected to the cyclone C1.

[0033] The center blade 10 having a long length L1 can easily deliver the cement raw materials to the radial center of the duct D2 where the gas flow velocity is high. This preheater 2 can charge the cement raw materials while dispersing them throughout the radial direction of the duct D2. Therefore, it is preferable that the length L1 of the center blade 10 is longer than the length L2 of the side blades 11.

[0034] The partition wall 12 prevents the cement raw material on the center blade 10 from being blown up by the gas rising on the radial outside of the duct D2. The center blade 10 having the partition wall 12 makes it easier for the cement raw material to reach the radial center of the duct D2. Therefore, it is preferable that the dispersion plate 6 has the partition wall 12 at the width direction end of the center blade 10.

[0035] The distribution plate 6, whose tip is located inside the duct D2, can easily make the cement raw materials reach the target charging position in the radial direction of the duct D2 by the center blade 10 and the side blades 11. Therefore, it is preferable that the tip of the distribution plate 6 is located inside the duct D2.

[0036] The appropriate angles for the elevation angle θ1 of the center blade 10 and the elevation angle θ2 of the side blades 11 vary depending on the operating conditions of the preheater 2, such as the amount of cement raw material and the temperature and flow rate of the gas in duct D2. In this preheater 2, the shaft 7 to which the center blade 10 and the side blades 11 are attached is rotatable. The preheater 2 can change the elevation angle θ1 of the center blade 10 and the elevation angle θ2 of the side blades 11 according to the operating conditions. Therefore, it is preferable that the shaft 7 be rotatable. In addition, it is preferable that the preheater 2 be equipped with a positioning device 13.

[0037] In this preheater 2, the structures of the connection parts between duct D3 and chute S4, between duct D4 and chute S5, and between duct D5 and chute S6 are the same as the structure of the connection part between duct D2 and chute S3. In this preheater 2, dispersion plates 6 are also located at the inlet of chute S4, the inlet of chute S5, and the inlet of chute S6.

[0038] 6 shows a preheater 14 according to another embodiment. Here, the configuration different from the preheater 2 will be described. Furthermore, the same components as those in the preheater 2 will be described using the same reference numerals, and the description of the same components will be omitted.

[0039] The preheater 14 includes a dispersion plate 15. The dispersion plate 15 has a center blade 16, a pair of side blades 17, and a partition wall 18.

[0040] The preheater 14 includes a center rotation shaft 19 to which a center blade 16 is attached and which is supported by the chute S3, and a handle 20 fixed to the center rotation shaft 19. The center rotation shaft 19 is rotatable relative to the chute S3. By rotating the handle 20, the center rotation shaft 19 and the center blade 16 are rotatable relative to the chute S3.

[0041] The preheater 14 includes a side rotation shaft 21 to which a pair of side blades 17 are attached and which is supported by the chute S3, and a handle 22 fixed to the side rotation shaft 21. The side rotation shaft 21 is rotatable relative to the chute S3. By rotating the handle 22, the side rotation shaft 21 and the pair of side blades 17 can be rotated relative to the chute S3.

[0042] FIG. 7A shows a cross section of the center blade 16, center pivot shaft 19, and handle 20 taken along line VIIA-VIIA in FIG. 6. In FIG. 7A, the shapes of the side blades 17 and side pivot shaft 21 are shown by two-dot chain lines. FIG. 7B shows a cross section of the side blades 17, side pivot shaft 21, and handle 22 taken along line VIIB-VIIB in FIG. 6. In FIG. 7B, the shapes of the center blade 16 and partition wall 18 are shown by two-dot chain lines. In the dispersion plate 15, the side pivot shaft 21 is supported by the chute S3. The side pivot shaft 21 is shaped like a hollow pipe having a hollow hole 21A. The center pivot shaft 19 passes through the hollow hole 21A of the side pivot shaft 21. The center pivot shaft 19 is supported by the chute S3 via the side pivot shaft 21.

[0043] The preheater 14 can individually adjust the elevation angle θ1 of the center blade 16 and the elevation angle θ2 of the pair of side blades 17. The preheater 14 can individually adjust the elevation angle θ1 of the center blade 16 and the elevation angle θ2 of the side blades 17 depending on the usage conditions of the preheater 2, such as the amount of cement raw material and the temperature and flow rate of the gas in the duct D2. Therefore, the preheater 14 preferably has a center rotation shaft 19 that rotatably supports the center blade 16 and a side rotation shaft 21 that rotatably supports the side blades 17.

[0044] Similarly to the positioning member 13 of the dispersion plate 6, the preheater 14 preferably includes a center blade positioning member capable of fixing the rotational position of the center blade 16 and a side blade positioning member capable of fixing the rotational position of the side blade 17.

[0045] [Disclosure items] Each of the following sections discloses a preferred embodiment.

[0046] [Item 1] A cyclone that separates the heat-exchanged gas from the cement raw materials; a duct for introducing the gas and the raw material into the cyclone; a chute having an inlet for introducing the raw material into the duct; and, a dispersion plate located at the inlet of the chute, extending from inside the chute toward the duct, for dispersing the raw material introduced into the duct; The preheater has side blades located on the outer side of the dispersion plate in the width direction, and a center blade located more centrally in the width direction than the side blades, the angle of elevation of which with respect to a plane perpendicular to the axis of the duct being greater than the angle of elevation of the side blades.

[0047] According to this configuration, the cement raw materials can be dispersed and charged into the gas inside the duct.

[0048] [Item 2] 2. The preheater according to item 1, further comprising a precyclone connected to the cyclone by the duct, the discharged gas being guided to the cyclone by the duct.

[0049] This configuration can prevent the cement raw material from falling from the duct into the precyclone connected to the cyclone by the duct. This configuration is suitable for a configuration in which the cement raw material is introduced into a duct connected to the precyclone.

[0050] [Item 3] 3. The preheater according to item 1 or 2, wherein the length of the center blade is longer than the length of the side blades.

[0051] With this configuration, the cement raw material can easily reach the center of the duct in the radial direction.

[0052] [Item 4] 4. The preheater according to any one of items 1 to 3, wherein the dispersion plate has a partition wall at the width direction end of the center blade.

[0053] With this configuration, the cement raw material can easily reach the center of the duct in the radial direction.

[0054] [Item 5] 5. The preheater according to any one of items 1 to 4, wherein a tip of the dispersion plate is located inside the duct.

[0055] According to this configuration, the cement raw materials can be easily delivered to the target charging position in the radial direction of the duct.

[0056] [Item 6] 6. The preheater according to any one of items 1 to 5, further comprising a center rotation shaft that rotatably supports the center blade and a side rotation shaft that rotatably supports the side blades.

[0057] With this configuration, the elevation angle of the center blade, which disperses the cement raw material in the radial center of the duct, and the elevation angle of the side blade, which disperses the cement raw material in the radial peripheral portions of the duct, can be adjusted separately. [Explanation of symbols]

[0058] C1, C2, C3, C4, C5... Cyclone C1, C2, C3, C4... Pre-cyclone D2, D3, D4, D5... ducts S3, S4, S5, S6...Shoot A3...Inlet θ1, θ2...Elevation angle L1, L2...length 2. Preheater 6, 14...dispersion plate 10, 16...Center blade 11, 17 Side blades 12, 18... Partition wall 19. Center pivot shaft 21 Side pivot shaft

Claims

1. A cyclone that separates the heat-exchanged gas from the cement raw materials; a duct for introducing the gas and the raw material into the cyclone; a chute having an inlet for introducing the raw material into the duct; and, a dispersion plate located at the inlet of the chute, extending from inside the chute toward the duct, for dispersing the raw material introduced into the duct; The preheater has side blades located on the outer side of the dispersion plate in the width direction, and a center blade located more centrally in the width direction than the side blades, the angle of elevation of which with respect to a plane perpendicular to the axis of the duct being greater than the angle of elevation of the side blades.

2. 2. The preheater of claim 1, further comprising a precyclone connected to the cyclone by the duct, the precyclone having exhaust gases directed to the cyclone by the duct.

3. 3. The preheater according to claim 1, wherein the length of the center blade is longer than the length of the side blades.

4. 3. The preheater according to claim 1, wherein the dispersion plate has a partition wall at an end in the width direction of the center blade.

5. 3. The preheater according to claim 1, wherein a tip of the dispersion plate is located inside the duct.

6. 3. The preheater according to claim 1, further comprising a center rotation shaft that rotatably supports the center blade, and side rotation shafts that rotatably support the side blades.

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