Rotary kiln with internal spiral structure

Abstract

The utility model discloses a rotary kiln with an internal spiral structure, and belongs to the technical field of titanium dioxide production equipment. The heat-insulating spiral blade comprises a barrel body and a spiral blade arranged in the barrel body, wherein the barrel body comprises a shell and a heat-insulating layer arranged on the inner wall of the shell; a plurality of spirally-distributed connecting pieces are embedded in the heat preservation layer, one end of each connecting piece is connected with the inner wall of the shell, and the other end of each connecting piece extends out of the heat preservation layer and is used for being connected with a spiral blade. Compared with a traditional rotary kiln in which the spiral blades are fixed on the kiln bricks, the connecting pieces are embedded in the heat preservation layer, so that firm connecting points can be formed between the spiral blades and the shell, the operation stability of the spiral blades is improved, and the spiral blades are not prone to falling off.

Description

Technical Field

[0001] The utility model belongs to the technical field of titanium dioxide production equipment, and more specifically relates to a rotary kiln with an inner spiral structure. Background Art

[0002] Titanium dioxide, commonly known as titanium dioxide, is considered to be the best white pigment in the world. It has pure whiteness, high refractive index of light, fine powder with suitable particle size and particle size distribution, stable to light and heat, and chemical inertness. Titanium dioxide is an important raw material in the chemical industry, widely used in papermaking, coatings, plastics, inks, papermaking, rubber, ceramics, enamel or fillers. It is recognized as the best white pigment so far, accounting for more than 80% of all white pigments used.

[0003] In the production of titanium dioxide, in order to transform titanium dioxide into rutile, the calcination process needs to use a rotary kiln to dry the material. In actual use, in order to strengthen the pushing of the rotary kiln and reduce the backflow of materials, an internal spiral needs to be set. For example, in the patent CN209893924U, a rotary kiln body with a spiral guide on the inner wall is disclosed. The application includes a metal shell, an insulation layer and a spiral feeding guide rail arranged in sequence from the outside to the inside, wherein: the spiral feeding guide rail is formed by stacking refractory bricks along a spiral trajectory, and the insulation layer is also paved with refractory bricks; extending from the rotary kiln feeding part to the drying section, preheating section, raw material decomposition section, firing section and cooling section of the rotary kiln body; the spiral feeding guide rail is formed by stacking a number of special-shaped refractory bricks, each of which includes at least a mounting bottom and a material guide protrusion, wherein the material guide protrusion extends toward the center of the kiln body, and the mounting bottom is stacked on the insulation layer. The rotary kiln body with inner wall spiral material guide in this application increases the contact time and contact area between materials such as cement and fly ash and the inner wall of the kiln body when the materials are dried, preheated, decomposed, calcined and cooled in the rotary kiln body.

[0004] For another example, in the patent CN215413098U, a spiral feed type rotary kiln head is disclosed. The application includes a kiln head body, a first spiral segment, a second spiral segment and a third spiral segment, wherein the first spiral segment, the second spiral segment and the third spiral segment are sequentially arranged inside the kiln head body, and the first spiral segment is located at the entrance of the kiln head body. The application embeds three spiral guide plates on the inner wall of the kiln body of the traditional rotary kiln, which not only retains the circumferential rolling and axial movement, but also because of the newly embedded three spiral guide plates, the material can be evenly pushed by the guide plates after entering the feed port, so that the material is evenly calcined, and the product quality is greatly improved.

[0005] The above applications all set spiral guide plates in the kiln body to strengthen the kiln push and reduce the material spillage. However, the spiral guide plates in the above applications are fixed on the kiln bricks and are prone to falling off. Utility Model Content

[0006] 1. Problems to be solved

[0007] In view of the problem that the existing spiral guide plate of the rotary kiln is directly fixed on the kiln brick, which is easy to fall off, the utility model provides a rotary kiln with an inner spiral structure. The utility model embeds a connecting piece in the insulation layer and then uses the connecting piece to fix the inner spiral, thereby effectively improving the firmness of the spiral connection in the rotary kiln and the stability of operation.

[0008] 2. Technical solution

[0009] In order to solve the above problems, the technical solution adopted by the utility model is as follows:

[0010] The utility model discloses a rotary kiln with an inner spiral structure, comprising a cylinder and spiral blades arranged in the cylinder, wherein the cylinder comprises an outer shell and a heat-insulating layer arranged on the inner wall of the outer shell;

[0011] A plurality of connecting pieces distributed in a spiral pattern are embedded in the thermal insulation layer. One end of the connecting piece is connected to the inner wall of the outer shell, and the other end extends out of the thermal insulation layer for connecting the spiral blades.

[0012] Furthermore, the insulation layer includes refractory bricks and casting areas that are spaced apart along the axial direction of the cylinder; wherein the connecting parts are located in the corresponding casting areas.

[0013] Furthermore, the connecting member comprises a frame of a U-shaped structure, the bottom of the frame is connected to the inner wall of the shell, the top of the frame extends out of the casting area and is connected to a cover plate, and the cover plate is used to connect the spiral blades.

[0014] Furthermore, reinforcing ribs are provided inside the frame.

[0015] Furthermore, the spiral blade is equipped with four connecting parts within one pitch, and the four connecting parts are distributed at equal intervals.

[0016] Furthermore, the height of the spiral blade is 500-700 mm.

[0017] Furthermore, there are four spiral blades, which are evenly distributed in the cylinder.

[0018] Furthermore, the plurality of spiral blades are connected in the axial direction via longitudinal ribs and in the radial direction via reinforcing rings.

[0019] Furthermore, embedded parts are provided between the refractory bricks and the casting area.

[0020] Furthermore, the refractory bricks are connected to the inner wall of the shell via anchoring pieces.

[0021] 3. Beneficial effects

[0022] Compared with the prior art, the beneficial effects of the utility model are:

[0023] (1) The utility model is a rotary kiln with an inner spiral structure. A connecting piece is embedded in the insulation layer. One end of the connecting piece is connected to the inner wall of the outer shell, and the other end extends out of the insulation layer and is connected to the spiral blade. Thus, a firm connection point can be formed between the spiral blade and the outer shell, which is beneficial to improving the stability of the spiral blade and preventing it from falling off.

[0024] (2) The utility model provides a rotary kiln with an inner spiral structure, wherein the insulation layer includes refractory bricks and a casting area spaced apart along the axial direction of the cylinder, and the connecting parts are located in the corresponding casting areas. The setting of the casting areas facilitates the construction of the insulation layer on the one hand; on the other hand, the casting areas can be used to replace the direct splicing between traditional refractory bricks, which is beneficial to reducing the splicing gap; at the same time, the connection strength between the refractory bricks and the casting area can be enhanced by setting embedded parts between the refractory bricks and the casting area.

[0025] (3) The utility model provides a rotary kiln with an inner spiral structure. By designing the height of the spiral blades, the material discharge is effectively controlled without causing excessive interference to the air flow in the cylinder.

[0026] (4) The utility model provides a rotary kiln with an inner spiral structure, which can further improve the stability of the connection between the plurality of spiral blades by providing a reinforcing ring and longitudinal ribs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of a rotary kiln with an inner spiral structure of the utility model;

[0028] Figure 2 This is a cross-sectional view of a rotary kiln with an inner spiral structure according to the utility model;

[0029] Figure 3 It is a structural schematic diagram of the connecting piece in the utility model.

[0030] In the figure: 1, cylinder; 11, shell; 12, insulation layer; 121, refractory brick; 122, casting area;

[0031] 2. Spiral blades;

[0032] 3. Connector; 31. Frame; 32. Cover plate; 33. Reinforcement rib;

[0033] 4. Reinforcement ring; 5. Longitudinal ribs. DETAILED DESCRIPTION

[0034] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings.

[0035] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0036] The utility model is further described below in conjunction with specific embodiments.

[0037] like Figure 1 , Figure 2 As shown, a rotary kiln with an inner spiral structure of this embodiment includes a cylinder 1 and a spiral blade 2 arranged in the cylinder 1. The spiral blade 2 rotates synchronously with the rotation of the cylinder 1 to assist in material transportation and prevent material from falling over.

[0038] Specifically, the cylinder 1 includes an outer shell 11 and an insulation layer 12 disposed on the inner wall of the outer shell 11. A plurality of connectors 3 are embedded in the insulation layer 12, one end of the connector 3 is connected to the inner wall of the outer shell 11, and the other end extends out of the insulation layer 12 for connecting the spiral blade 2. At the same time, the plurality of connectors 3 are distributed in a spiral shape as a whole to match the rotation direction of the spiral blade 2.

[0039] In the rotary kiln with an inner spiral structure of the present embodiment, the connection piece 3 is provided so that a firm connection point can be formed between the spiral blade 2 and the outer shell 11, which is beneficial to improving the running stability of the spiral blade 2 and preventing it from falling off.

[0040] As an implementation of the thermal insulation layer 12, in this embodiment, the thermal insulation layer 12 includes refractory bricks 121 and casting areas 122 spaced apart along the axial direction of the cylinder 1, and the connector 3 is located in the corresponding casting area 122. Each section of the refractory bricks 121 and the casting area 122 are arranged on the inner wall of the outer shell 11.

[0041] In this embodiment, the refractory bricks 121 and the pouring area 122 are designed in an interval ring, so that the refractory bricks 121 are separated by the pouring area 122. Compared with the direct splicing between traditional refractory bricks 121, replacing part of the refractory bricks 121 with the pouring area 122 can effectively reduce the size of the splicing seam.

[0042] At the same time, in order to ensure the connection strength between the refractory bricks 121 and the pouring area 122, embedded parts can be set between the refractory bricks 121 and the pouring area 122 before pouring. Of course, in order to improve the connection strength between the refractory bricks 121 and the shell 11, the two can be connected by anchors. The specific connection method of the anchors can refer to the existing technology and will not be described in detail.

[0043] In addition, it should be noted that, although the present embodiment adopts a structural mode in which the refractory bricks 121 and the pouring area 122 are arranged at intervals, other arrangements are not excluded, for example, the pouring area 122 is only left at the position where the connector 3 needs to be installed. That is, the pouring area 122 is an installation space surrounded by refractory bricks 121 on four sides, rather than an annular channel surrounded by refractory bricks 121 on two sides.

[0044] refer to Figure 3 As shown, as a specific embodiment of the connecting member 3, the connecting member 3 includes a U-shaped frame 31, the bottom of which is connected to the inner wall of the housing 11. The top of the frame 31 extends out of the casting area 122 and is connected to a cover plate 32, which is used to connect the spiral blade 2.

[0045] Preferably, the bottom of the frame 31 is an arc-shaped structure matching the inner wall of the housing 11, and the bottom of the frame 31 and the inner wall of the housing 11, the top of the frame 31 and the cover plate 32, and the cover plate 32 and the spiral blade 2 can all be connected by welding. In addition, in order to ensure the overall structural strength of the frame 31, a reinforcing rib 33 can be provided in the frame 31.

[0046] The construction steps of this embodiment are as follows: first, the frame 31 and the cover plate 32 are prefabricated in the factory, and if there are reinforcing ribs 33, the reinforcing ribs 33 need to be welded to the frame 31 to form a whole. However, at this time, the frame 31 and the cover plate 32 are separated from each other.

[0047] Next, the rotary kiln is constructed and positioned to determine the location of the pouring area 122. Next, the refractory brick 121 lining is carried out. After the refractory brick 121 is lined to a specific position (pouring area), the frame 31 is welded, the castable is made, and the cover plate 32 is welded after solidification. Finally, the spiral blade 2 is welded to the cover plate 32.

[0048] In this embodiment, as an implementation of the spiral blade 2, the spiral blade 2 is equipped with multiple connectors 3 within one pitch, and the multiple connectors 3 are evenly spaced. Here, evenly spaced distribution means that the projection points of the multiple connectors 3 along the radial direction of the cylinder 1 are equal.

[0049] Preferably, the spiral angle of the spiral blade 2 is 30-60°, for example, 35°, 45°, 55°, etc., and the direction of the spiral blade 2 is consistent with the overall flow direction of the material, that is, from the kiln head to the kiln tail. At the same time, the height D of the spiral blade 2 is preferably controlled at 500-700mm, for example, 520mm, 580mm, 680mm, etc. The height should be selected to have a stopping effect on the material and prevent the material from falling back; on the other hand, it should not cause too much obstruction to the airflow in the cylinder 1.

[0050] The height D of the spiral blade 2 mentioned above refers to the distance between the inner end surface and the outer end surface of the cross section of the spiral blade 2, that is, half of the difference between the outer diameter and the inner diameter of the spiral blade 2.

[0051] Specifically in this embodiment, the helical pitch angle of the spiral blade 2 is 40 degrees; the height of the spiral blade 2 is about 650; and each spiral blade 2 is equipped with 4 connecting members 3 within one pitch.

[0052] As another implementation of this embodiment, there are four spiral blades 2, which are evenly distributed in the cylinder 1. That is, the starting points of the four spiral blades 2 are evenly distributed in a ring shape on the same annular cross section of the cylinder 1.

[0053] At the same time, in order to ensure the stability of the connection between the multiple spiral blades 2, a reinforcement ring 4 and a longitudinal rib 5 are provided between the multiple spiral blades 2. Among them, the reinforcement ring 4 is used to strengthen the connection of the multiple spiral blades 2 in the radial direction; the longitudinal rib 5 is used to strengthen the connection of the multiple spiral blades 2 in the axial direction.

[0054] The above schematically describes the present invention and its implementation methods, which are not restrictive. The drawings show only one implementation method of the present invention, and the actual structure is not limited thereto. Therefore, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A rotary kiln with an inner spiral structure, comprising a cylinder (1) and a spiral blade (2) arranged in the cylinder (1), characterized in that: The cylinder (1) comprises an outer shell (11) and a heat-insulating layer (12) arranged on the inner wall of the outer shell (11); A plurality of spirally distributed connecting pieces (3) are embedded in the thermal insulation layer (12); one end of the connecting piece (3) is connected to the inner wall of the outer shell (11), and the other end extends out of the thermal insulation layer (12) for connecting to the spiral blade (2).

2. The rotary kiln with an inner spiral structure according to claim 1, characterized in that: The thermal insulation layer (12) comprises refractory bricks (121) and a casting area (122) which are spaced apart along the axial direction of the cylinder; wherein the connecting piece (3) is located in the corresponding casting area (122).

3. The rotary kiln with an inner spiral structure according to claim 2, characterized in that: The connecting member (3) comprises a frame (31) of a U-shaped structure, the bottom of the frame (31) being connected to the inner wall of the outer shell (11), the top of the frame (31) extending outside the casting area (122) and being connected to a cover plate (32), and the cover plate (32) being used to connect the spiral blade (2).

4. The rotary kiln with an inner spiral structure according to claim 3, characterized in that: The frame (31) is provided with reinforcing ribs (33).

5. The rotary kiln with an inner spiral structure according to claim 1, characterized in that: The spiral blade (2) is equipped with four connecting pieces (3) within one pitch, and the four connecting pieces (3) are distributed at equal intervals.

6. The rotary kiln with an inner spiral structure according to claim 1, characterized in that: The height of the spiral blade (2) is 500-700 mm.

7. A rotary kiln with an inner spiral structure according to any one of claims 1 to 6, characterized in that: There are four spiral blades (2) which are evenly distributed inside the cylinder (1).

8. The rotary kiln with an inner spiral structure according to claim 7, characterized in that: The plurality of spiral blades (2) are connected in the axial direction via longitudinal ribs (5) and in the radial direction via reinforcing rings (4).

9. The rotary kiln with an inner spiral structure according to claim 2, characterized in that: Embedded parts are provided between the refractory bricks (121) and the pouring area (122).

10. The rotary kiln with an inner spiral structure according to claim 9, characterized in that: The refractory bricks (121) are connected to the inner wall of the outer shell (11) via anchoring pieces.

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