A circular ring belt type light-burned magnesite calcining kiln

Abstract

The utility model relates to calcining kiln technical field especially relates to a circular ring belt type light burning magnesite calcining kiln. Include: kiln body and cloth arrangement, the kiln body is divided into outer kiln body and inner kiln body, the wall body place of outer kiln body and inner kiln body middle area respectively bulges to two sides direction, just the inner kiln body with outer kiln body between form the circular ring belt type heating area of big upper, lower two end port small, middle abdomen, the outer kiln body top is equipped with the cloth arrangement of heating area intercommunication, the heating area middle part position is divided into a plurality of storage space by the evenly distributed inner partition, the below of each storage space is equipped with the combustion chamber, the above of each combustion chamber is equipped with the grate support combination, the below of combustion chamber is equipped with the storage and unloading spare; the utility model through the structural design and the layout between the inner and outer kiln body, has increased the stone processing capacity, and the kiln body is in the negative pressure state simultaneously, avoids the smoke and dust to the external space diffusion, accords with the environmental protection production demand.

Description

Technical Field

[0001] This utility model relates to the field of calcining kiln technology, and in particular to a circular belt type light-burning magnesite calcining kiln. Background Technology

[0002] Magnesite processing mainly relies on the decomposition reaction of magnesium carbonate (MgCO3) at high temperatures to produce magnesium oxide (MgO) and carbon dioxide (CO2). The high-temperature environment generated by fuel combustion provides the heat required for the decomposition of magnesite, promoting the smooth progress of the reaction. Due to the limitations of its own structure, the production scale of existing calcining kilns is affected by the number of kiln bodies, and they use a single type of fuel. They also generate a lot of smoke and dust pollution during processing, which does not meet the environmental protection requirements of current production. Therefore, there is an urgent need for an environmentally friendly calcining kiln that can maintain high-efficiency production. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a circular belt light-burning magnesite calcining kiln in response to the above-mentioned technical deficiencies. Through the structural design and layout between the inner and outer kiln bodies, the stone processing capacity is increased. At the same time, the kiln body is in a negative pressure state to prevent smoke and dust from spreading to the external space, which meets the requirements of environmentally friendly production.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is a circular belt-type light-burning magnesite calcining kiln, comprising: a kiln body and a material distribution device. The kiln body is divided into an outer kiln body and an inner kiln body. The walls of the middle area of ​​the outer kiln body and the inner kiln body bulge outwards to both sides, and a circular belt-type heating zone with small upper and lower ends and a large middle section is formed between the inner kiln body and the outer kiln body. A material distribution device communicating with the heating zone is installed on the top of the outer kiln body. The middle position of the heating zone is divided into multiple material storage spaces by evenly distributed inner partition walls. A combustion chamber is provided below each of the material storage spaces. A grate support assembly is provided above each of the combustion chambers. A storage and unloading device is provided below the combustion chamber.

[0005] Preferably, multiple external burners are installed in the combustion chamber along the circumferential direction of the outer and inner kiln bodies.

[0006] The preferred grate support assembly consists of several arched grate bars and a support beam. The support beam is vertically fixed in the heating zone, and the multiple arched grate bars are arranged at equal intervals along the upper end of the support beam. The arched grate bars and the support beam are prefabricated using special heat-resistant materials.

[0007] Preferably, the grate support assembly is provided with fire-drawing holes penetrating the outer kiln body and the inner kiln body at both the top and bottom, and the fire-drawing holes are evenly distributed along the circumferential direction.

[0008] Preferably, the feeder adopts a rotary feeder structure.

[0009] Preferably, the storage and unloading component includes a storage hopper and an unloading valve assembly. Multiple storage hoppers are arranged circumferentially below the combustion chamber and are in communication with the lower opening of the combustion chamber. The inlet of the unloading valve assembly matches the outlet of the corresponding storage hopper.

[0010] Preferably, a finished product storage bin is provided directly below the inner kiln body, and the finished product storage bin is connected to the discharge port of the unloading valve assembly.

[0011] Compared with the prior art, the present invention has the following advantages: 1. The multi-point rotating feeder structure in the feeding assembly keeps the internal space of the kiln closed during the feeding process, effectively preventing the leakage of smoke and dust. At the same time, the heating zone itself is under negative pressure, which solves the problem of leakage in traditional kilns. 2. The high-temperature flue gas generated in the combustion chamber is reflected onto the material through the grate support assembly, realizing calcination processing. At the same time, it preheats the ore above, shortens the heating time, and the bulging structure formed by the bulge in the middle can increase the residence time of the ore and improve the preheating effect. 3. The unloading valve assembly can collect the calcined material falling into the storage hopper, realize the unloading operation, make the discharge safer, and reduce the labor intensity of workers; 4. The burner is designed to be compatible with a variety of fuels, making it widely applicable and easy to customize for customers, reducing procurement costs and facilitating widespread application. 5. The combustion chamber adopts a reflective calcination structure, and the calcination process is mature and reliable, which makes it easy for technicians to quickly master production, avoid blind spots, and shorten intermediate commissioning and production time. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the external structure of a circular belt-type light-burning magnesite calcining kiln. Figure 2 This is a schematic diagram of the internal structure of the kiln. Figure 3 This is a schematic diagram of the structure of the inner kiln body; Figure 4 This is a schematic diagram of the grate bar support assembly structure; Figure 5 This is a diagram showing the arrangement of the grate support assembly inside the kiln. Figure 6 This is a schematic diagram of the unloading valve assembly structure; Figure 7 This is a flowchart of the magnesite ore production process.

[0013] In the diagram: 1. Kiln body; 2. Material distribution device; 3. Grate support assembly; 4. Storage and unloading components; 5. Finished product storage bin; 101. Outer kiln body; 102. Inner kiln body; 103. Heating zone; 104. Inner partition wall; 105. Material storage space; 106. Combustion chamber; 107. Flame extraction hole; 301. Arched grate; 302. Support beam; 401. Material storage hopper; 402. Unloading valve assembly. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of this utility model.

[0015] Specific implementation method one: Combining Figure 1-7 As shown, a circular belt-type light-burning magnesite calcining kiln includes: a kiln body 1 and a feeding device 2. The kiln body 1 is divided into an outer kiln body 101 and an inner kiln body 102. The walls of the middle area of ​​the outer kiln body 101 and the inner kiln body 102 bulge outwards to both sides, forming a circular belt-type heating zone 103 with small upper and lower ends and a large middle section. The feeding device 2, which communicates with the heating zone 103, is installed on the top of the outer kiln body 101. The stone entering through the feeding device 2 is piled up in the heating zone 103 and supported by a grate bar combination located above the combustion chamber. The middle of the heating zone 103 is divided into multiple storage spaces 105 by evenly distributed inner partition walls 104. The storage spaces are used to store and divide the stone. In later maintenance, damage... When replacing a damaged grate support assembly, it is not necessary to empty the materials in other storage spaces; only the damaged one needs to be repaired. Below each storage space 105, there is a combustion chamber 106, and below the combustion chamber 106, there is a storage and unloading component 4. After the stone material is heated by the high-temperature flue gas and reacts and breaks, it falls into the storage and unloading component 4 through the grate support assembly 6. At the same time, the flue gas continues to rise, which can preheat the stone material accumulated in the heating zone 101. Then, the flue gas is discharged through the storage belt. After being discharged, the flue gas passes through the dust collector and is discharged into the atmosphere through the chimney by the induced draft fan. Furthermore, the walls of the middle area of ​​the outer kiln body 101 and the inner kiln body 102 bulge outwards to both sides, forming a bulging structure, which facilitates increasing the residence time of the ore and enhances the preheating effect of the ore.

[0016] Preferred embodiments, in combination Figure 1As shown, multiple external burners are installed in the combustion chamber 106 along the circumference of the outer kiln body 101, that is, the burners are installed in the middle area of ​​the outer kiln body 101. At the same time, burners are also installed at the corresponding height position of the inner kiln body 102. The burners are arranged in the hollow position in the center of the inner kiln body 102. The fuel used by the burners can be gas, liquid or solid, or any combination of two, which has wide applicability and is easy to match and modify the fuel system in the plant area.

[0017] Preferred embodiments, in combination Figure 3 and Figure 4 As shown, the grate support assembly 3 consists of several arched grates 301 and a support beam 302. The support beam 302 is vertically fixed in the heating zone 103. The multiple arched grates 301 are arranged at equal intervals along the upper end of the support beam 302. One end of the arched grates 301 is fixed to the side wall of the inner partition wall 104, and the other end is connected to the adjacent arched grates 301. At the same time, a support beam 302 structure is added at the connection of the arched grates 301 to provide end support and ensure its own strength. In order to meet the requirements of high temperature environment, the arched grates 301 and the support beam 302 are prefabricated with special heat-resistant materials, such as silicon carbide and zirconium oxide.

[0018] Preferred embodiments, in combination Figure 2 and Figure 3 As shown, a ring of fire-dispelling holes 107 is formed along the circumference of the outer kiln body 101 and the inner kiln body 102. The height of the fire-dispelling holes 107 is located above the grate support assembly 3, so as to push the calcined stone material down. Similarly, a ring of fire-dispelling holes 107 is formed along the circumference of the outer kiln body 101 and the inner kiln body 102. The height of the fire-dispelling holes 102 is located below the grate support assembly 6. This allows the reacted ore to fall and be ignited, preventing blockage. Furthermore, the kiln body is under negative pressure, which can effectively avoid the traditional leakage phenomenon and protect the safety of the workers.

[0019] Preferred embodiments, in combination Figure 2 and Figure 6 As shown, several storage hoppers 401 are evenly arranged below the combustion chamber 106. Each storage hopper 401 corresponds to a discharge valve assembly 402. Together, they form a storage and discharge component 4. The burned material falls into the finished product storage bin 5 through the discharge valve assembly 402, and the finished product is transferred to the discharge belt by the vibrating feeder set under the finished product storage bin 5.

[0020] Preferred embodiments, in combination Figure 2As shown, the feeding device 2 adopts a multi-point rotating feeder structure. When the feeder receives material, the feeding bell is closed and the receiving door is opened. After receiving material, the receiving door is closed and the feeding bell is opened, and the feeder begins to feed material into the heating zone. The feeder rotates 60 degrees each time to achieve six-point feeding, ensuring that the raw material is evenly distributed across the entire kiln cross-section, improving the uniformity of feeding. Furthermore, throughout the feeding process, the control of the receiving door and feeding bell valves ensures that the kiln interior remains closed, and the kiln environment is always isolated from the outside, preventing the leakage of flue gas, ensuring a clean production environment, and meeting the requirements of environmentally friendly processing.

[0021] Working principle: Qualified raw materials smaller than 240mm are transported to the kiln front silo by a loader. Under the traction of the winch, the magnesite is conveyed to the multi-point rotating distributor at the top of the inner and outer kiln bodies by the feeding trolley. The multi-point rotating distributor evenly adds the ore into the heating zone 103. The kiln front silo, vibrating feeder, weighing hopper, winch, feeding trolley, feeding inclined bridge and multi-point rotating distributor together form the feeding assembly.

[0022] After the ore is evenly distributed by the distributor, natural gas or pulverized coal is used as fuel in the combustion chamber 106, with pulverized coal preferred. The ore is fully combusted in the combustion chamber 106 to produce high-temperature flue gas. The high-temperature flue gas is supported by the grate bar assembly 3 and reflected onto the accumulated magnesite material between the inner walls of the outer kiln body 101 and the inner kiln body 102, achieving indirect heating. The temperature of the heating zone 103 is controlled at 800-1000 degrees Celsius, and the calcination time is 2-4 hours to ensure that the magnesite is fully decomposed. The burner in the combustion chamber 106 is a multi-channel gas burner for light-burned magnesite. The primary air and gas channels can be adjusted, and the pulverized coal burner is used in conjunction with the combustion fan to generate combustion air. The combustion air can exchange heat with the hot air cooled by the drum cooler to improve combustion efficiency and reduce energy consumption. Several combustion chambers 106 are evenly arranged around the kiln body 1 to ensure uniform heating of each storage space 105 area.

[0023] The ore on the grate support assembly 3 is calcined by the flame at the combustion chamber 106. The decomposed small particles fall into the storage hopper 401 below through the gaps between the arched grate bars 301, and are discharged into the finished product storage bin 5 by the corresponding discharge valve assembly 402. Then, it is conveyed to the drum cooler by the plate chain conveyor. The cooled finished product is sent into the feeding hopper of the jaw crusher, and is crushed by the vibrating feeder. After crushing, it is sent into the Raymond mill feed hopper by the elevator. The lightly calcined magnesia that has passed the Raymond mill's qualified particle size is packed into ton bags and placed in the finished product warehouse by the crane.

[0024] Regarding flue gas treatment, the flue gas generated by combustion enters the bag filter directly through pipelines from four evenly distributed exhaust ports on the top conical section of the outer kiln body 101. A cold air mixing valve is installed at the inlet of the dust collector. When the exhaust gas temperature is too high, cold air is mixed in to protect the dust collector. After dust removal, the flue gas is sent to the chimney by an induced draft fan and discharged in compliance with standards. The dust concentration of the gas is less than 10mg / Nm3. When the emission of nitrogen oxides in the flue gas exceeds the standard, an integrated denitrification device is installed to ensure that SO2 and NOx can be discharged in compliance with standards.

[0025] The kiln body 1 has a production capacity of 150-500T / D and is highly flexible in operation, with adjustments from 50-110% to achieve stable production without affecting product quality or consumption indicators. It is compatible with various fuels, including natural gas, heavy oil, pulverized coal, producer gas, coke oven gas, and mixed gas, making it easy to modify and adapt. In addition, temperature, pressure, and flow monitoring instruments can be added to various parts inside the kiln body 1 to enable the entire device to meet automated control requirements.

[0026] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within its protection scope. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A circular belt-type calcining kiln for lightly calcined magnesite, characterized in that, include: The kiln body and the material distribution device are provided. The kiln body is divided into an outer kiln body and an inner kiln body. The walls of the middle area of ​​the outer kiln body and the inner kiln body bulge outwards to both sides. The inner kiln body and the outer kiln body form a circular heating zone with small upper and lower ends and a large middle section. The top of the outer kiln body is equipped with a material distribution device that communicates with the heating zone. The middle part of the heating zone is divided into multiple material storage spaces by evenly distributed inner partition walls. Each material storage space is equipped with a combustion chamber below it. Each combustion chamber is equipped with a grate support assembly above it. A storage and unloading device is provided below the combustion chamber.

2. The annular belt-type light-burning magnesite calcining kiln according to claim 1, characterized in that: Multiple external burners are installed in the combustion chamber along the circumference of the outer and inner kiln bodies.

3. The annular belt-type light-burning magnesite calcining kiln according to claim 1, characterized in that: The grate support assembly consists of several arched grate bars and a support beam. The support beam is vertically fixed in the heating zone. The multiple arched grate bars are arranged at equal intervals along the upper end of the support beam. The arched grate bars and the support beam are prefabricated using special heat-resistant materials.

4. The annular belt-type light-burning magnesite calcining kiln according to claim 1, characterized in that: The grate support assembly is provided with fire-drawing holes at both the top and bottom, penetrating the outer and inner kiln bodies, and the fire-drawing holes are evenly distributed along the circumferential direction.

5. A circular belt-type light-burning magnesite calcining kiln according to claim 1, characterized in that: The fabric-making device employs a multi-point rotating fabric-making device.

6. The annular belt-type light-burning magnesite calcining kiln according to claim 1, characterized in that: The storage and unloading components include a storage hopper and an unloading valve assembly. Multiple storage hoppers are arranged circumferentially below the combustion chamber and are in communication with the lower opening of the combustion chamber. The inlet of the unloading valve assembly matches the outlet of the corresponding storage hopper.

7. A circular belt-type light-burning magnesite calcining kiln according to claim 6, characterized in that: The inner kiln body is provided with a finished product storage bin directly below it, and the finished product storage bin is connected to the discharge port of the unloading valve assembly.

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