Low-carbon cement clinker calcining and decomposing system and using method

Abstract

The invention discloses a low-carbon cement clinker calcining and decomposing system and a using method, the low-carbon cement clinker calcining and decomposing system comprises a suspension preheating device, a heating and decomposing device and a material collecting device, and the heating and decomposing device is used for receiving preheated materials, decomposing the materials and correspondingly conveying the materials to the material collecting device; the thermal decomposition device comprises a combustion heating cavity fixedly arranged outside and a rotating cylinder set concentrically arranged in the combustion heating cavity, and the rotating cylinder set comprises an inner cylinder, an outer cylinder and a plurality of middle cylinders located between the inner cylinder and the outer cylinder, according to the thermal decomposition device, through the concentrically-arranged rotating barrel body sets, the fulcrum distance is short, the overall length can be shortened, the equipment manufacturing cost is reduced, meanwhile, through the design of the spiral blades in the barrel bodies, it can be guaranteed that under the condition that the length of the barrel bodies is shortened again, the thermal decomposition efficiency is improved, and the thermal decomposition efficiency is improved. The heating moving distance of the material is ensured, the material can be fully decomposed, and the calcining and decomposing quality is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of cement clinker processing, and in particular to a low-carbon cement clinker calcining and decomposition system and a use method thereof. Background Art

[0002] The cyclone preheater decomposition furnace used in the current cement kiln and lime kiln industry is that the fuel is burned at high temperature in the decomposition furnace, and the high-temperature airflow is transmitted to the material to decompose the calcium carbonate material. The decomposed carbon dioxide is mixed with the gas from the combustion of the fuel, resulting in a low concentration of carbon dioxide and high impurities in the decomposition of materials such as calcium carbonate, which are basically discharged into the atmosphere. Even if the carbon dioxide is recovered, the equipment investment for carbon dioxide purification is large, the purification process is complex, the production cost is very high, it is very uneconomical, and it puts great pressure on energy conservation and emission reduction. At present, there is also a suspension preheater plus an external combustion rotary kiln process to recover carbon dioxide and decompose limestone, magnesite, dolomite, or high-calcium coal gangue, but the diameter and length of the rotary kiln are large. The common rotary kiln diameter ranges from 3.2 to 6 meters and the length spans from 45 to 120 meters. The equipment investment and civil engineering investment are large, the construction period is long, and the equipment operation cost is also high. It causes a large energy loss during calcination and decomposition, which is conducive to the energy-saving and efficient production of cement clinker and other products. Summary of the invention

[0003] Technical purpose: In view of the shortcomings of the existing rotary kilns for cement clinker calcination production, the present invention discloses a low-carbon cement clinker calcination decomposition system and a method of use which occupies a small space and can achieve efficient production and processing.

[0004] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution: A low-carbon cement clinker calcining and decomposition system comprises a suspension preheating device, a heating and decomposition device and a material collecting device, wherein the heating and decomposition device is used to receive preheated materials for decomposition and convey them to the material collecting device accordingly; the heating and decomposition device comprises an externally fixed combustion and heating chamber, and a rotating cylinder group is concentrically arranged in the combustion and heating chamber, wherein the rotating cylinder group comprises a concentrically arranged inner cylinder, an outer cylinder and a plurality of intermediate cylinders located between the inner cylinder and the outer cylinder, and the cylinder walls of adjacent cylinders are relatively fixed by a connecting frame, the inner cylinder is connected to a rotating power source, and when the materials are heated and decomposed, the plurality of cylinders of the rotating cylinder group are driven to rotate synchronously by the inner cylinder; spiral blades for material conveying are arranged on the inner wall of the cylinder, and along the material conveying direction, the end of the outer cylinder is connected to the material collecting device.

[0005] Preferably, the middle cylinder and the outer cylinder of the present invention both adopt a structure with one end open, and the opening directions of two adjacent layers of cylinders are opposite. After the material enters from the inner cylinder, it is transported to the outer cylinder layer by layer by the middle cylinder.

[0006] Preferably, the conveying direction of the spiral blades in the cylinder of the present invention is toward the opening direction of the cylinder.

[0007] Preferably, the inner cylinder of the present invention adopts a hollow shaft, one end of the hollow shaft is connected to the material outlet of the suspension preheating device, and the other end is connected to the rotating power source. A middle partition is arranged on the side of the hollow shaft close to the rotating power source, and the hollow shaft is divided into a material chamber and a cooling chamber by the middle partition. The position of the cooling chamber corresponds to the material outlet of the outer cylinder, and the material is cooled by injecting cooling water into the cooling chamber.

[0008] Preferably, the hollow shaft of the present invention is provided with an opening groove for cooling water to enter and exit on the wall surface at a position corresponding to the cooling cavity.

[0009] Preferably, a water receiving cone is provided in the cooling cavity of the present invention, and the end of the water receiving cone faces the side where the middle partition is located, so as to guide the cooling water entering the cooling cavity to the side where the middle partition is located.

[0010] Preferably, the material collecting device of the present invention comprises a double-shell spiral auger conveyor corresponding to the material outlet on the opening side of the outer cylinder, a finished product bin and a bag dust collector, wherein the double-shell spiral auger conveyor receives the powdered material and transports it to the finished product bin after cooling, and the bag dust collector receives the gaseous material produced by decomposition, filters and removes the dust, and then transports the gas to the corresponding purification system.

[0011] Preferably, the combustion and heating chamber of the present invention uses a tunnel kiln, and a plurality of combustion nozzles are arranged on the kiln wall of the tunnel kiln. The outer cylinder body is heated by the combustion nozzles. An asbestos sealing ring is arranged on the wall surface close to the opening side of the outer cylinder body to separate the combustion and heating chamber formed by the tunnel kiln from the interior of the outer cylinder body. The asbestos sealing ring prevents the smoke from the combustion of the fuel from entering the outer cylinder body.

[0012] The present invention discloses a method for using the low-carbon cement clinker calcining and decomposition system according to the above-mentioned method, wherein the material is first preheated by a suspension preheating device, and then the material enters from the inner cylinder, and in the combustion and heating chamber, the rotating cylinder group is heated by fuel combustion; when the inner cylinder rotates, the material gradually moves along the guiding action of the spiral blades to the connecting area between the inner cylinder and the middle cylinder, enters the middle cylinder, and is transported to the outer cylinder layer by layer through the spiral blades in the cylinder. In this process, the material exchanges heat with the cylinder to be decomposed, and finally enters the material collecting device from the opening side of the outer cylinder.

[0013] Preferably, in the present invention, when the decomposed material enters the material collecting device from the outer cylinder, cooling water is injected into the cooling cavity at the end of the inner cylinder to perform heat exchange cooling on the discharged material.

[0014] Beneficial effects: The low-carbon cement clinker calcination and decomposition system and use method disclosed in the present invention have the following beneficial effects: 1. The heating decomposition device of the present invention has a rotating cylinder group arranged concentrically, and the fulcrum distance is short, which can shorten the overall length and reduce the equipment cost. At the same time, the design of the spiral blades in the cylinder can ensure that the heating movement distance of the material is guaranteed when the cylinder length is further shortened, so that it can be fully decomposed and the calcination decomposition quality is guaranteed.

[0015] 2. The cylinders of the present invention are connected by a connecting frame, and the connecting frame can also play a role of heat conduction, so that the material can be fully heated during the rotation of the cylinder; and the structure of the middle cylinder and the outer cylinder with one end open can cooperate with the setting direction of the spiral blade to realize the automatic transfer of materials between the cylinders during the rotation process, realize the automatic movement of materials, and simplify the structure inside the cylinder.

[0016] 3. The inner cylinder of the present invention directly utilizes the hollow shaft to ensure the transmission of rotational power while avoiding the problems of installation and material conveying caused by the separate setting of the rotating shaft, thereby facilitating the assembly of the structure.

[0017] 4. The hollow shaft of the inner cylinder of the present invention is divided by a middle partition to form an independent material chamber and cooling chamber. By injecting cooling water into the cooling chamber, the decomposed material can be cooled simultaneously during the calcination of cement clinker, which is convenient for collection by subsequent collection devices.

[0018] 5. The present invention sets a water receiving cone in the cooling chamber, and guides the incoming cooling water through the water receiving cone so that it can be evenly distributed in the cooling chamber, thereby ensuring the cooling effect of the decomposed material and improving the cooling efficiency.

[0019] 6. The combustion and heating chamber of the present invention is separated from the outer cylinder by an asbestos sealing ring, which can separate the calcined gas and the smoke generated by combustion, so that the carbon dioxide generated by the decomposition of the material can be collected and processed separately. The recovered carbon dioxide has a concentration of more than 95%, which is more conducive to the production of food-grade carbon dioxide, increasing the high added value of products, improving economic benefits, reducing carbon emissions to the atmosphere, and realizing low-carbon production.

[0020] 7. The present invention uses a suspended preheating device to preheat the material. The heat source can be the flue gas generated by combustion, and the heat is recycled, thereby making full use of energy, reducing consumption, and achieving energy-saving production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0022] Figure 1 It is a schematic diagram of the overall structure of the system of the present invention; Figure 2 It is a cross-sectional schematic diagram of the thermal decomposition device of the present invention; Figure 3 It is a schematic diagram of the structure of the rotating cylinder group of the present invention; Among them, 1-combustion and heating chamber, 2-inner cylinder, 3-outer cylinder, 4-middle cylinder, 5-rotational power source, 6-spiral blades, 7-middle partition, 8-material chamber, 9-cooling chamber, 10-water receiving cone, 11-double-shell spiral auger conveyor, 12-finished product warehouse, 13-bag dust collector, 14-asbestos sealing ring, 15-water collecting tank. DETAILED DESCRIPTION

[0023] Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are set forth herein below. Each embodiment and example is provided by way of explanation of the apparatus, composition and materials of the present disclosure, rather than limitation. On the contrary, the following description provides a convenient illustration of an exemplary embodiment for implementing the present disclosure. In fact, it will be clear to those skilled in the art that various modifications and variations may be made in the teachings of the present disclosure without departing from the scope or spirit of the present disclosure.

[0024] like Figure 1-Figure 3 As shown, the present invention discloses a low-carbon cement clinker calcining and decomposition system, comprising a suspension preheating device, a heating and decomposition device and a material collecting device, wherein the heating and decomposition device is used to receive the preheated material for decomposition and correspondingly convey it to the material collecting device; the heating and decomposition device comprises an externally fixed combustion and heating chamber 1, a rotating cylinder group concentrically arranged in the combustion and heating chamber 1, the rotating cylinder group comprises a concentrically arranged inner cylinder 2, an outer cylinder 3 and a plurality of intermediate cylinders 4 located between the inner cylinder 2 and the outer cylinder 3, the cylinder walls of adjacent cylinders are relatively fixed by a connecting frame, the inner cylinder 2 is connected to a rotating power source 5, and when the material is heated and decomposed, the plurality of cylinders of the rotating cylinder group are driven to rotate synchronously by the inner cylinder 2; a spiral blade 6 for material conveying is arranged on the inner wall of the cylinder, and along the material conveying direction, the end of the outer cylinder 3 is connected to the material collecting device.

[0025] The suspension preheating device adopts a multi-stage cyclone preheater, including cyclone cylinders C1, C2, C3, C4, and C5. The material first enters the heat exchange ascending pipe of the C2 cyclone cylinder, and then enters the C1 cyclone cylinder with the airflow. After being captured and collected in the C1 cylinder, it enters the C3 heat exchange ascending pipe through the discharge pipe, and then enters the C2 cyclone cylinder with the airflow. After being captured and collected in the C2 cylinder, it enters the C4 heat exchange ascending pipe through the discharge pipe, and then enters the C3 cyclone cylinder with the airflow. After being captured and collected in the C3 cylinder, it enters the C5 heat exchange ascending pipe through the discharge pipe, and then enters the C4 cyclone cylinder with the airflow. After being captured and collected in the C4 cyclone cylinder, it enters the inner cylinder body 2 through the discharge pipe of the C4 cyclone cylinder. The heat exchange gas used in the cyclone cylinder can use fuel. The combustion flue gas in the combustion heating chamber 1, the combustion heating chamber of the present invention uses a tunnel kiln, a plurality of combustion nozzles are arranged on the kiln wall of the tunnel kiln, the outer cylinder 3 is heated by the combustion nozzles, an asbestos sealing ring 14 is arranged on the wall surface close to the opening side of the outer cylinder 3 to separate the combustion heating chamber 1 formed by the tunnel kiln from the inner part of the outer cylinder 3, the asbestos sealing ring 14 is used to prevent the flue gas of the fuel combustion from entering the outer cylinder 3, and the flue gas generated by the combustion is introduced into the suspension preheating device for utilization, which can realize the recycling of energy, thereby reducing energy loss, and at the same time, the existence of the asbestos sealing ring 14 separates the decomposition space of the material from the fuel combustion space, which can ensure the purity of the decomposition gas of the material, and is convenient for subsequent purification and utilization. It also avoids the mixing of carbon dioxide and fuel combustion gas in the prior art, resulting in low concentration of carbon dioxide and high impurities from the decomposition of materials such as calcium carbonate, large equipment investment for carbon dioxide purification, and complex purification process, which is not convenient for recycling and energy saving and emission reduction.

[0026] To ensure the time for heating and decomposing the material of the present invention, Figure 3 As shown, the intermediate cylinder 4 and the outer cylinder 3 of the present invention both adopt a structure with one end open, the opening directions of the two adjacent layers of cylinders are opposite, and the conveying direction of the spiral blades 6 in the cylinder is toward the opening direction of the cylinder. After the material enters from the inner cylinder 2, the spiral blades 6 are used to convey the material to the opening side of the corresponding cylinder, and are conveyed to the outer cylinder layer by layer by the intermediate cylinder 4, thereby extending the heating and decomposition path of the material, thereby ensuring that it can be fully thermally decomposed, ensuring the heating and decomposition effect of the material while occupying a small installation space, and reducing the cost of the calcination equipment; at the same time, the present invention directly uses the structure of the cylinder itself to realize the transfer of materials, without the need to design a separate transfer device, thereby simplifying the structural design in the cylinder, facilitating the smooth movement of materials, and reducing the overall equipment cost.

[0027] The inner cylinder 2 of the present invention is directly formed by a hollow shaft, and both ends of the hollow shaft extend out of the combustion and heating chamber and rotate with the combustion and heating chamber. One end of the hollow shaft is connected to the material outlet of the suspension preheating device, and the other end is connected to the rotating power source 5. A middle partition 7 is arranged on the side of the hollow shaft close to the rotating power source 5, and the hollow shaft is divided into a material chamber 8 and a cooling chamber 9 by the middle partition 7. The material chamber 8 is used to receive the preheated material for decomposition. The position of the cooling chamber 9 corresponds to the material outlet of the outer cylinder 3, and the material is cooled by injecting cooling water into the cooling chamber 9; the rotating power source 5 adopts a permanent magnet motor, and a coupling is used to connect the output shaft of the permanent magnet motor and the end of the intermediate shaft.

[0028] The hollow shaft of the present invention has an open groove for the entry and exit of cooling water on the wall surface corresponding to the cooling chamber 9. The cooling water enters from the upper open groove and flows out from the lower open groove. The cooling water can be collected by setting a water collecting tank 15 below. Since the cooling water does not directly contact the material, it can be repeatedly recycled.

[0029] In order to improve the cooling effect, a water receiving cone 10 is arranged in the cooling chamber 9 of the present invention, and the end of the water receiving cone 10 is directed to the side where the middle partition 7 is located, so that the cooling water entering the cooling chamber 9 is guided to the side where the middle partition 7 is located, so that after the cooling water enters from the open groove, it will not flow out directly from the open groove on the other side, but will flow to the side where the middle partition 7 is located under the drive of the water receiving cone 10, so that the cooling water can be evenly distributed in the cooling chamber 9, thereby ensuring the cooling effect of the decomposed material.

[0030] The material collecting device of the present invention comprises a double-shell spiral auger conveyor 11, a finished product bin 12 and a bag dust collector 13 corresponding to the material outlet on the opening side of the outer cylinder 3. The double-shell spiral auger conveyor 11 receives the powdered material and conveys it to the finished product bin 12 after cooling. The decomposed material is further cooled by introducing cooling water into the gap between the double shells, and finally directly conveyed to the finished product bin 12 for storage. The heat absorbed by the cooling water heat exchange can be connected to the water system to utilize the waste heat; the bag dust collector 13 receives the gaseous material produced by the decomposition, filters and removes the dust, and then conveys the gas to the corresponding purification system. The filtered dust is still material, so it can also be conveyed to the finished product bin 12 after accumulation reaches a certain level.

[0031] The present invention discloses a method for using the above-mentioned low-carbon cement clinker calcining and decomposition system, wherein the material is first preheated by a suspension preheating device, and then enters from the inner cylinder, and in the combustion and heating chamber, the rotating cylinder group is heated by fuel combustion; when the inner cylinder rotates, the material gradually moves along the guiding action of the spiral blades to the connecting area between the inner cylinder and the middle cylinder, enters the middle cylinder, and is transported to the outer cylinder layer by layer through the spiral blades in the cylinder. During this process, the material exchanges heat with the cylinder to be decomposed, and finally enters the material collecting device from the opening side of the outer cylinder. When the decomposed material enters the material collecting device from the outer cylinder, the present invention cools the discharged material by injecting cooling water into the cooling chamber at the end of the inner cylinder for heat exchange.

[0032] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A low carbon cement clinker calcination and decomposition system, characterized in that: The invention comprises a suspension preheating device, a heating decomposition device and a material collecting device, wherein the heating decomposition device is used to receive the preheated material for decomposition and convey it to the material collecting device accordingly; the heating decomposition device comprises an externally fixed combustion heating chamber (1), a rotating cylinder group arranged concentrically in the combustion heating chamber (1), the rotating cylinder group comprising a concentrically arranged inner cylinder (2), an outer cylinder (3) and a plurality of intermediate cylinders (4) located between the inner cylinder (2) and the outer cylinder (3), the cylinder walls of adjacent cylinders being relatively fixed by a connecting frame, the inner cylinder (2) being connected to a rotating power source (5), and when the material is heated and decomposed, the plurality of cylinders of the rotating cylinder group are driven to rotate synchronously by the inner cylinder (2); a spiral blade (6) for conveying the material is arranged on the inner wall of the cylinder, and along the material conveying direction, the end of the outer cylinder (3) is connected to the material collecting device.

2. A low carbon cement clinker calcination and decomposition system according to claim 1, characterized in that: The intermediate cylinder (4) and the outer cylinder (3) both adopt a structure with one end open, and the opening directions of two adjacent cylinders are opposite. After the material enters from the inner cylinder (2), it is transported to the outer cylinder layer by layer by the intermediate cylinder (4).

3. A low carbon cement clinker calcining and decomposition system according to claim 2, characterized in that: The conveying direction of the spiral blades (6) in the cylinder is towards the opening direction of the cylinder.

4. A low carbon cement clinker calcining and decomposition system according to claim 2, characterized in that: The inner cylinder (2) adopts a hollow shaft, one end of which is connected to the material outlet of the suspension preheating device, and the other end of which is connected to the rotary power source (5). A middle partition (7) is provided on the side of the hollow shaft close to the rotary power source (5), and the hollow shaft is divided into a material chamber (8) and a cooling chamber (9) by the middle partition (7). The position of the cooling chamber (9) corresponds to the material outlet of the outer cylinder (3), and the material is cooled by injecting cooling water into the cooling chamber (9).

5. A low carbon cement clinker calcining and decomposition system according to claim 4, characterized in that: The hollow shaft is provided with an opening groove for the inlet and outlet of cooling water on a wall surface at a position corresponding to the cooling cavity (9).

6. A low carbon cement clinker calcining and decomposition system according to claim 5, characterized in that: A water receiving cone (10) is disposed in the cooling cavity (9), with the end of the water receiving cone (10) facing the side where the middle baffle (7) is located, so as to guide the cooling water entering the cooling cavity (9) to the side where the middle baffle (7) is located.

7. The low carbon cement clinker calcining and decomposition system according to claim 1, characterized in that: The material collecting device comprises a double-shell screw auger conveyor (11) corresponding to the material outlet on the opening side of the outer cylinder (3), a finished product bin (12) and a bag dust collector (13); the double-shell screw auger conveyor (11) receives the powdered material and conveys it to the finished product bin (12) after cooling; the bag dust collector (13) receives the gaseous material generated by decomposition, performs filtering and dust removal treatment, and then conveys the gas to a corresponding purification system.

8. A low carbon cement clinker calcining and decomposition system according to claim 7, characterized in that: The combustion and heating chamber uses a tunnel kiln, and a plurality of combustion nozzles are arranged on the kiln wall of the tunnel kiln. The outer cylinder (3) is heated by the combustion nozzles. An asbestos sealing ring (14) is arranged on the wall surface close to the opening side of the outer cylinder (3) to separate the combustion and heating chamber (1) formed by the tunnel kiln from the interior of the outer cylinder (3). The asbestos sealing ring (14) prevents smoke generated by combustion of fuel from entering the outer cylinder (3).

9. A method for using the low carbon cement clinker calcining and decomposition system according to any one of claims 1 to 8, characterized in that: The material is first preheated by a suspension preheating device, and then enters from the inner cylinder. In the combustion and heating chamber, the rotating cylinder group is heated by fuel combustion. When the inner cylinder rotates, the material gradually moves along the guiding action of the spiral blades to the connecting area between the inner cylinder and the middle cylinder, enters the middle cylinder, and is transported layer by layer to the outer cylinder through the spiral blades in the cylinder. In this process, the material exchanges heat with the cylinder for decomposition, and finally enters the material collection device from the opening side of the outer cylinder.

10. The method for using a low-carbon cement clinker calcining and decomposition system according to claim 9, characterized in that: When the decomposed materials enter the material collecting device from the outer cylinder, cooling water is injected into the cooling cavity at the end of the inner cylinder to perform heat exchange cooling on the discharged materials.

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