A rotary cooling device for calcined high-activity light-burned magnesium oxide

Abstract

The utility model relates to the technical field of rotary cooling waste heat recovery equipment, in particular to a rotary cooling device for calcining high-activity light-burned magnesium oxide, comprising a hollow short kiln cylinder, the left and right sides of the top of the hollow short kiln cylinder are fixedly sleeved with wheel belts, the bottom of the wheel belt is provided with a supporting wheel, and the middle end of the surface of the hollow short kiln cylinder is fixedly sleeved with a large gear ring. The utility model solves the problem that the apparent decomposition rate of light-burned magnesium oxide powder calcined by a suspended preheating decomposition furnace is currently low and cannot meet the CBM96 ignition loss ≤2% requirement, and can adjust the apparent decomposition rate of the material; the apparent decomposition rate of magnesium carbonate of the preheating decomposition furnace material (i.e., magnesite powder) is 90% to 95%, and the decomposition reaction continues to proceed through the heat storage device, reaching more than 98%, producing high-activity light-burned magnesium oxide with ignition loss ≤2%, and the waste heat of the rotary cooler is introduced into the decomposition furnace to provide it with combustion-supporting hot air, thereby reducing energy consumption.

Description

Technical Field

[0001] The utility model relates to the technical field of rotary cooling waste heat recovery equipment, in particular to a rotary cooling device for calcined high-activity light-burned magnesium oxide. Background Art

[0002] At present, the reverberatory furnace vertical kiln used to calcine light-burned magnesium oxide powder with magnesite in China cannot directly calcine powdered materials. With the urgent need for the utilization of mining resources, some companies have adopted suspended preheating decomposition furnaces to directly calcine magnesite flotation concentrate powder and waste magnesite fine particle powder to produce light-burned magnesium oxide powder, but there are few examples of successful operation and normal production. The successful use of suspended preheating decomposition furnace technology is the rotary kiln in my country's cement industry, which makes the apparent decomposition rate of calcium carbonate entering the kiln reach 90% to 95%.

[0003] The ignition loss index of CBM96 light-burned magnesium oxide (YB / T5206-2004) is ≤2%. According to the formula of apparent decomposition rate of raw materials entering the pre-decomposition kiln system:

[0004] λ=10000(Ls-Lr) / Ls(100-Lr), when Ls=51.82%, Lr≤2%, it is calculated that λ≥98%, that is, the apparent decomposition rate of the magnesite powder after calcination must be greater than 98%.

[0005] λ is the apparent decomposition rate of raw materials entering the kiln;

[0006] Ls is the loss on ignition of magnesite powder;

[0007] Lr is the ignition loss of light-burned magnesium oxide;

[0008] When light-burned magnesium oxide powder is calcined in a suspended preheating decomposition furnace, the apparent decomposition rate of magnesite powder and magnesium carbonate is between λ=90% and 95%, and the ignition loss Lr is between 9.7% and 5.1%, which does not meet the CBM96 ignition loss ≤ 2% requirement, and can only produce light-burned magnesium oxide powder below the grade CBM92.

[0009] In order to solve the above technical problems, we have designed a rotary cooling device for calcined high-activity light-burned magnesium oxide. Utility Model Content

[0010] The utility model aims to provide a rotary cooling device for calcined high-activity light-burned magnesium oxide, which has the advantage of high apparent decomposition rate of magnesia powder and solves the problem that the apparent decomposition rate of light-burned magnesium oxide powder calcined in a suspended preheating decomposition furnace is low and cannot meet the CBM96 ignition loss ≤2% requirement.

[0011] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a rotary cooling device for calcined high-activity light-burned magnesium oxide, comprising a hollow short kiln cylinder, the left and right sides of the top of the hollow short kiln cylinder are fixedly sleeved with wheel belts, the bottom of the wheel belts is provided with supporting wheels, the middle end of the surface of the hollow short kiln cylinder is fixedly sleeved with a large gear ring, the bottom of the large gear ring is meshed with a small gear, an electric motor is installed on the right side of the small gear, a kiln lining is fixedly connected to the inner wall of the left side of the inner cavity of the hollow short kiln cylinder, and aluminum silicate thermal insulation cotton is inlaid on the inner wall of the right side of the inner cavity of the hollow short kiln cylinder, and an arc-shaped material plate is fixedly connected to the surface of the aluminum silicate thermal insulation cotton.

[0012] Preferably, a second coupling is fixedly installed on the output shaft of the motor, and a reducer is fixedly installed on the left side of the second coupling.

[0013] Preferably, the output end of the reducer is fixedly connected with a coupling 1, and the left side of the coupling 1 is fixedly connected to the right side of the pinion.

[0014] Preferably, the hollow short kiln cylinder is divided into two parts, the left part of the hollow short kiln cylinder is the kiln tail, and the right part of the hollow short kiln cylinder is the kiln head.

[0015] Preferably, a rising smoke chamber is provided on the left side of the kiln tail, a discharge pipe is provided on the right side of the kiln head, and sealing structures are provided between the connection between the kiln tail and the rising smoke chamber and between the kiln head and the discharge pipe.

[0016] Preferably, the kiln head is sealed by a cover shell air-sealed labyrinth plus a spring steel sheet flexibility, and the kiln tail is sealed by a steel sheet plus a graphite flexibility.

[0017] Preferably, a stopper wheel is provided on one side of the wheel belt, and the kiln tail and the kiln head are arranged between the decomposition furnace and the cyclone preheater group.

[0018] Preferably, the wheel belt is arranged on the hollow short kiln shell at an inclination angle of 1 to 2 degrees to the horizontal, and the kiln lining is made of refractory material.

[0019] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0020] The utility model provides a material exiting a preheating decomposition furnace and entering a rotary cooling waste heat recovery device for buffering heat exchange, thereby increasing the process of the material continuing to undergo a decomposition reaction in the rotary cooling waste heat recovery device and adjusting the apparent decomposition rate of the material; the apparent decomposition rate of the magnesium carbonate in the material exiting the preheating decomposition furnace (i.e., magnesite powder) is made to be 90% to 95%, and the decomposition reaction is continued through the heat storage device to reach more than 98%, and the ignition loss of the produced high-activity light-burned magnesium oxide is ≤2%, and the waste heat of the rotary cooler is introduced into the decomposition furnace to provide the decomposition furnace with combustion-supporting hot air, thereby reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the utility model;

[0022] Figure 2 This is a schematic diagram of the AA section of the utility model;

[0023] Figure 3 It is a BB cross-sectional schematic diagram of the utility model.

[0024] In the figure: 1. Hollow short kiln shell; 2. Wheel belt; 3. Big gear ring; 4. Kiln lining; 5. Support wheel; 6. Block wheel; 7. Pinion; 8. Reducer; 9. Electric motor; 10. Kiln head; 11. Kiln tail; 12. Coupling 1; 13. Coupling 2; 14. Sealing structure; 15. Aluminum silicate insulation cotton; 16. Arc-shaped material plate. DETAILED DESCRIPTION

[0025] See also Figure 1-Figure 3 A rotary cooling device for calcined high-activity light-burned magnesium oxide, comprising a hollow short kiln cylinder 1, a wheel belt 2 is fixedly sleeved on both the left and right sides of the top of the hollow short kiln cylinder 1, a supporting wheel 5 is arranged at the bottom of the wheel belt 2, a large gear ring 3 is fixedly sleeved on the middle end of the surface of the hollow short kiln cylinder 1, a small gear 7 is meshed at the bottom of the large gear ring 3, a motor 9 is installed on the right side of the small gear 7, a kiln lining 4 is fixedly connected to the inner wall of the left side of the inner cavity of the hollow short kiln cylinder 1, an aluminum silicate thermal insulation cotton 15 is inlaid on the inner wall of the right side of the inner cavity of the hollow short kiln cylinder 1, and an arc-shaped material plate 16 is fixedly connected to the surface of the aluminum silicate thermal insulation cotton 15;

[0026] See also Figure 1 The output shaft of the motor 9 is fixedly mounted with a coupling 13, and the left side of the coupling 13 is fixedly mounted with a reducer 8;

[0027] See also Figure 1 , the output end of the reducer 8 is fixedly connected with a coupling 12, and the left side of the coupling 12 is fixedly connected to the right side of the pinion 7;

[0028] See also Figure 1 The hollow short kiln cylinder 1 is divided into two parts, the left part of the hollow short kiln cylinder 1 is the kiln tail 11, and the right part of the hollow short kiln cylinder 1 is the kiln head 10;

[0029] See also Figure 1 A rising smoke chamber is arranged on the left side of the kiln tail 11, a discharge pipe is arranged on the right side of the kiln head 10, and a sealing structure 14 is arranged between the connection between the kiln tail 11 and the rising smoke chamber, and between the connection between the kiln head 10 and the discharge pipe;

[0030] See also Figure 2 and Figure 3The kiln head 10 is sealed by a cover gas seal labyrinth plus a spring steel sheet, and the kiln tail 11 is sealed by a steel sheet plus a graphite sheet.

[0031] See also Figure 1 A stopper wheel 6 is provided on one side of the wheel belt 2, and a kiln tail 11 and a kiln head 10 are provided between the decomposition furnace and the cyclone preheater group;

[0032] See also Figure 1 and Figure 2 The wheel belt 2 is arranged on the hollow short kiln shell 1 at an inclination angle of 1 to 2 degrees with the horizontal, and the kiln lining 4 is made of refractory material, and the thickness of the kiln lining 4 is 100-150mm;

[0033] This device is arranged between the decomposition furnace and the cyclone preheater group. It is a horizontal rotary cylinder. Because of its small aspect ratio (between 5-15%), it is referred to as a hollow short kiln. A rising smoke chamber is arranged at the feeding end of the kiln tail 11 and connected with the bottom of the decomposition furnace. After the material from the preheated decomposition furnace enters the hollow short kiln, it is buffered for heat exchange, waste heat recovery and cooling. The material from the rotary cooler is the light-burned magnesium oxide product. The waste hot flue gas from the kiln tail 11 is introduced into the bottom of the decomposition furnace through the rising smoke chamber and the hot air generated by the cyclone preheater as the combustion-supporting hot air of the decomposition furnace. The design of technical parameters should meet the requirement that the material stays in the kiln for 10 minutes. The aspect ratio of the hollow short kiln cylinder 1 is between 5-10%, and the equipment manufacturing has met the requirements of technical standards.

[0034] The retention time of materials in the rotary cooling waste heat recovery device is set to 10 minutes, and the decomposition reaction continues to proceed, so that the decomposition rate of the kiln materials reaches more than 98%; the high-temperature waste heat flue gas (700℃) of the device enters the decomposition furnace from the bottom of the decomposition furnace, and merges with the hot air entering the decomposition furnace with the cyclone cooling waste heat, providing the decomposition furnace with combustion-supporting hot air, saving energy. When the preheater decomposition furnace produces fluctuations in the production process, such as material collapse and temperature drop, the device plays the role of material buffering, and continues to decompose by supplementary burning, instead of directly entering the cyclone cooler and becoming unqualified products or waste products to cause losses.

[0035] When in use, a refractory kiln lining 4 is inlaid on the kiln tail 11 part of the hollow short kiln cylinder 1, and an aluminum silicate insulation cotton 15 and an arc-shaped material plate 16 are inlaid on the inner wall of the kiln head 10 part to protect the hollow short kiln cylinder 1 and reduce its surface heat dissipation loss. Two belts 2 are arranged on the hollow short kiln cylinder 1 at an angle of 1 to 2 degrees to the horizontal, and are located on two pairs of supporting wheels 5 corresponding to the belts 2. The whole weight of the hollow short kiln cylinder 1 is transmitted to the supporting wheels 5 through the belts 2. The belts 2 roll on the supporting wheels 5 with the hollow short kiln cylinder 1, and also have the function of increasing the rigidity of the hollow short kiln cylinder 1. A stopper wheel 6 is arranged on one side of the belt 2, and the up and down movement of the hollow short kiln cylinder 1 can be controlled by the stopper wheel 6 to achieve uniform wear and extend the service life of the supporting wheels 5 and the belts 2. The invention is safe and reliable, and can realize automatic control of adjusting the up and down movement of the kiln cylinder. The transmission device is composed of a motor 9, a reducer 8, a large gear ring 3 and a small gear 7. The large gear ring 3 is meshed and connected with the small gear 7. The small gear 7 is sequentially connected with the reducer 8 and the motor 9 through a coupling 12 and a coupling 2 13. After the power is started, the motor 9 rotates to drive the reducer 8 through the coupling 2 13, and drives the small gear 7 and the large gear ring 3 to rotate through the coupling 1 12. The large gear ring 3 drives the hollow short kiln cylinder 1 to rotate. A sealing structure 14 is provided on the kiln head 10 and the kiln tail 11 to prevent the outside air from being sucked into the kiln. The kiln head 10 adopts a cover gas seal labyrinth plus a spring steel sheet flexible seal, and the kiln tail 11 adopts a steel sheet plus a graphite flexible seal.

[0036] In summary, the rotary cooling device for calcined high-activity light-burned magnesium oxide solves the problem that the apparent decomposition rate of light-burned magnesium oxide powder calcined in a suspended preheating decomposition furnace is low and cannot meet the CBM96 ignition reduction requirement of ≤2% through the coordination of a hollow short kiln cylinder 1, a wheel belt 2, a large gear ring 3, a kiln lining 4, a supporting wheel 5, a retaining wheel 6, a small gear 7, a reducer 8, an electric motor 9, a sealing structure 14, aluminum silicate insulation cotton 15 and an arc-shaped material plate 16.

Claims

1. A rotary cooling device for calcined high-activity light-burned magnesium oxide, comprising a hollow short kiln shell (1), characterized in that: Wheel bands (2) are fixedly sleeved on both left and right sides of the top of the hollow short kiln cylinder (1), and a supporting wheel (5) is arranged at the bottom of the wheel band (2). A large gear ring (3) is fixedly sleeved on the middle end of the surface of the hollow short kiln cylinder (1), and a small gear (7) is meshed at the bottom of the large gear ring (3). An electric motor (9) is installed on the right side of the small gear (7). A kiln lining (4) is fixedly connected to the inner wall of the left side of the inner cavity of the hollow short kiln cylinder (1), and an aluminum silicate thermal insulation cotton (15) is inlaid on the inner wall of the right side of the inner cavity of the hollow short kiln cylinder (1), and an arc-shaped material plate (16) is fixedly connected to the surface of the aluminum silicate thermal insulation cotton (15).

2. A rotary cooling device for calcined high-activity light-burned magnesium oxide according to claim 1, characterized in that: A second coupling (13) is fixedly mounted on the output shaft of the motor (9), and a reducer (8) is fixedly mounted on the left side of the second coupling (13).

3. A rotary cooling device for calcined high-activity light-burned magnesium oxide according to claim 2, characterized in that: The output end of the reducer (8) is fixedly connected to a coupling 1 (12), and the left side of the coupling 1 (12) is fixedly connected to the right side of the pinion (7).

4. A rotary cooling device for calcined high-activity light-burned magnesium oxide according to claim 1, characterized in that: The hollow short kiln cylinder (1) is divided into two parts, the left part of the hollow short kiln cylinder (1) is the kiln tail (11), and the right part of the hollow short kiln cylinder (1) is the kiln head (10).

5. A rotary cooling device for calcined high-activity light-burned magnesium oxide according to claim 4, characterized in that: A rising smoke chamber is arranged on the left side of the kiln tail (11), a discharge pipe is arranged on the right side of the kiln head (10), and a sealing structure (14) is arranged between the connection between the kiln tail (11) and the rising smoke chamber and between the connection between the kiln head (10) and the discharge pipe.

6. A rotary cooling device for calcined high-activity light-burned magnesium oxide according to claim 4, characterized in that: The kiln head (10) is sealed by a cover gas sealing labyrinth plus a spring steel sheet flexibility, and the kiln tail (11) is sealed by a steel sheet plus a graphite flexibility.

7. A rotary cooling device for calcined high-activity light-burned magnesium oxide according to claim 4, characterized in that: A stopper wheel (6) is arranged on one side of the wheel belt (2), and the kiln tail (11) and the kiln head (10) are arranged between the decomposition furnace and the cyclone preheater group.

8. A rotary cooling device for calcined high-activity light-burned magnesium oxide according to claim 1, characterized in that: The wheel belt (2) is arranged on the hollow short kiln shell (1) at an inclination angle of 1 to 2 degrees with respect to the horizontal, and the kiln lining (4) is made of refractory material.

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