Coal gangue self-heating segmented temperature control sintering device and sintering method thereof

Abstract

The present application relates to coal gangue sintering technical field, especially to a kind of coal gangue self-heating segmented temperature control sintering device and sintering method thereof, including kiln main body, kiln main body is sequentially set as preheating section, transition section, main sintering section and cooling section along coal gangue conveying direction, further include air distribution mechanism, it is set in main sintering section, including the side part air inlet piece distributed in the both sides of kiln main body, the top air inlet piece being set in the top of kiln main body and the bottom air inlet piece being set in the bottom of kiln main body, side part air inlet piece, top air inlet piece and bottom air inlet piece jointly constitute the three-dimensional air distribution structure around the main sintering section in kiln main body, the present application is by setting the three-dimensional air distribution structure by side part, top, bottom air inlet piece in main sintering section, and combining temperature monitoring unit and central controller arranged at multiple points, realize the independent, accurate control of the air supply amount of different areas in kiln, solve the problem of uneven section temperature, edge overburning and central clinkering caused by traditional single-side air supply.

Description

Technical Field

[0001] This invention relates to the field of coal gangue sintering technology, and in particular to a self-heating segmented temperature-controlled sintering device and sintering method for coal gangue. Background Technology

[0002] Coal gangue, as a solid waste generated during coal mining and washing, has always been a research hotspot in the field of resource utilization. Utilizing the combustibles contained in coal gangue for self-heating sintering to produce building materials such as porous bricks is one of the main ways to utilize coal gangue resources.

[0003] Currently, coal gangue sintering production typically uses tunnel kilns for continuous operation. In actual production, the self-heating combustion process of coal gangue is directly affected by the temperature field inside the kiln. The distribution of the temperature field is closely related to the air supply volume and location. The existing tunnel kiln has a relatively simple air supply structure, usually with a limited number of air inlets set on the side wall of the main firing section. The total air supply volume is controlled by manually adjusting the main air valve. This air supply method results in an extremely uneven air volume distribution on the cross section inside the kiln: the area near the air inlet has sufficient oxygen, and the coal gangue burns too vigorously, which easily leads to overburning; while the area far from the air inlet, especially the middle and lower parts of the kiln, has a serious lack of air supply, and the coal gangue does not burn completely, resulting in frequent underburning problems. This uneven combustion situation makes the sintering quality of the same batch of billets inconsistent, and it is difficult to improve the finished product qualification rate. Moreover, the self-heating characteristics of coal gangue fluctuate greatly during combustion. Once the air supply conditions and the combustion state are not matched, it is very easy for local temperatures to be too high, or for the kiln to shut down due to insufficient air supply.

[0004] Based on the above situation, it is necessary to design a self-heating segmented temperature-controlled sintering device for coal gangue and its sintering method to solve the above problems. Summary of the Invention

[0005] This invention provides a self-heating segmented temperature-controlled sintering device and sintering method for coal gangue to solve the problems existing in the prior art.

[0006] The technical problem solved by this invention is achieved by the following technical solution: A self-heating, segmented temperature-controlled sintering device for coal gangue includes a kiln body, wherein the kiln body is sequentially configured along the coal gangue conveying direction as a preheating section, a transition section, a main firing section, and a cooling section, and further includes: The air distribution mechanism, which is located in the main firing section, includes side air inlets distributed on both sides of the kiln body, top air inlets located on the top of the kiln body, and bottom air inlets located at the bottom of the kiln body. The side air inlets, top air inlets, and bottom air inlets together constitute a three-dimensional air distribution structure surrounding the main firing section inside the kiln body. A temperature monitoring unit, comprising multiple temperature elements disposed within the kiln body; The central controller is electrically connected to the temperature monitoring unit and the air distribution mechanism, respectively, and is used to independently adjust the opening of the side air inlet, the top air inlet and the bottom air inlet according to the received temperature data.

[0007] Preferably, the air distribution mechanism further includes: The main air supply duct is connected to an exhaust fan at its air inlet end; Multiple air distribution branch pipes are connected to the side air inlet, top air inlet and bottom air inlet, and the other end of each is connected to the air outlet of the main air supply duct. The first regulating valve is installed on the air distribution branch pipe and is used to independently control the air volume of each air distribution branch pipe.

[0008] Preferably, the temperature sensing element is a thermocouple electrically connected to the central controller, and the thermocouple is distributed in the preheating section, transition section, main firing section and cooling section, for collecting temperature signals of the corresponding sections respectively.

[0009] Preferably, it also includes a waste heat recovery mechanism, which includes: A heat collection shroud is installed at the top of the cooling section; The waste heat recovery pipe has its air inlet end connected to the air outlet end of the heat collection hood, and the air outlet end extends into the interior of the preheating section, which is used to guide the hot air from the cooling section to the preheating section.

[0010] Preferably, the waste heat recovery pipe is provided with a second regulating valve, which is connected to the central controller. The central controller adjusts the opening degree of the second regulating valve according to the temperature data of the preheating section.

[0011] Preferably, the main firing section is further equipped with a flue gas sensor electrically connected to the central controller for collecting flue gas composition data of the main firing section.

[0012] A sintering method for a self-heating, segmented temperature-controlled sintering device for coal gangue includes the following steps: S1: Initial gradient preheating: Coal gangue is fed into the preheating section for preheating treatment, so that the temperature of the billet gradually increases to the preset preheating temperature. S2: Transition buffer: The preheated coal gangue enters the transition section, where the temperature transitions smoothly, allowing the billet temperature to rise from the preset preheating temperature gradient to the preset firing start temperature. S3: Three-dimensional air distribution sintering: When coal gangue enters the main sintering section, the central controller independently adjusts the opening of the side air inlet, top air inlet and bottom air inlet according to the temperature data collected by the temperature monitoring unit. Air is supplied into the kiln from the side, top and bottom of the coal gangue at the same time, controlling the spontaneous combustion of combustibles in the coal gangue for sintering, so that the temperature of the main sintering section is maintained within the preset sintering temperature range. S4: Gradient cooling: The sintered billet enters the cooling section and is cooled to obtain the finished product.

[0013] Preferably, in step S3, the central controller also adjusts the opening of the side air inlet, top air inlet and bottom air inlet according to the flue gas composition data collected by the flue gas sensor installed in the main firing section, so as to control the oxygen concentration and / or carbon monoxide concentration in the main firing section within a preset range.

[0014] Preferably, in step S4, when the coal gangue is cooled in the cooling section, the hot air generated in the cooling section is collected by a heat collection hood set at the top of the cooling section, and the hot air is directionally introduced into the preheating section through the waste heat recovery pipe to preheat the billet in the preheating section.

[0015] The beneficial effects of this invention are as follows: By setting a three-dimensional air distribution structure consisting of side, top, and bottom air inlets in the main firing section, and combining it with a multi-point temperature monitoring unit and a central controller, this invention achieves independent and precise control of the air supply volume in different areas of the kiln. This solves the problem of uneven cross-sectional temperature and over-burning at the edges and under-burning in the middle caused by single-sided air supply in traditional tunnel kilns, ensuring that the self-heating combustion process of coal gangue is always under control and improving sintering uniformity. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the isometric structure provided by the present invention; Figure 2 This is a schematic diagram of the internal structure of the kiln body provided by the present invention; Figure 3 This is a schematic diagram of the air distribution structure provided by the present invention; Figure 4 This is a front view of the main body of the kiln in this invention; Figure 5 This is a schematic diagram of the process provided in this invention.

[0018] In the diagram, 1. Kiln body; 11. Preheating section; 111. Volatile matter outlet; 12. Transition section; 13. Main firing section; 14. Cooling section; 2. Side air inlet; 3. Top air inlet; 4. Bottom air inlet; 5. Temperature element; 6. Central controller; 7. Main air supply duct; 71. Exhaust fan; 72. Branch air distribution pipe; 73. First regulating valve; 8. Heat collection hood; 81. Waste heat recovery pipe; 82. Second regulating valve; 9. Flue gas sensor. Detailed Implementation

[0019] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0020] Reference Figures 1-5 As shown, a self-heating, segmented temperature-controlled sintering device for coal gangue includes a kiln body 1. The kiln body 1 is a long, horizontally extending tunnel-like structure with a continuous sintering channel inside. Along the coal gangue conveying direction, the kiln body 1 is sequentially configured with a preheating section 11, a transition section 12, a main firing section 13, and a cooling section 14. These functional sections are interconnected. A track for kiln cars is provided at the bottom. The preheating section 11 is located at the inlet end of the kiln body 1. Multiple volatile matter discharge outlets 111 are also provided at the top of the preheating section 11, connected to a main exhaust pipe (not shown in the figure). The transition section 12 connects the preheating section 11 and the main firing section 13. Between the transition section 12 and the cooling section 14, the main firing section 13 is located between the transition section 12 and the cooling section 14. The main firing section 13 is equipped with an air distribution mechanism, which includes side air inlets 2 distributed on both sides of the kiln body 1, top air inlets 3 located on the top of the kiln body 1, and bottom air inlets 4 located at the bottom of the kiln body 1. The side air inlets 2, top air inlets 3, and bottom air inlets 4 together form a three-dimensional air distribution structure around the main firing section 13 inside the kiln body 1. Through the three-dimensional multi-point air supply method, the cross-sectional air volume distribution inside the kiln body 1 is improved, and the problem of over-firing at the edges and under-firing in the middle caused by traditional single-sided air supply is solved, creating uniform sintering conditions for the self-heating combustion of coal gangue.

[0021] In addition, this solution also includes a temperature monitoring unit consisting of multiple temperature elements 5 installed in the kiln body 1 and a central controller 6. The central controller 6 is electrically connected to the temperature monitoring unit and the air distribution mechanism, and is used to independently adjust the opening of the side air inlet 2, the top air inlet 3 and the bottom air inlet 4 according to the received temperature data, so as to realize differentiated control of the temperature of different areas in the main firing section 13, so that the self-heating combustion process of coal gangue is always in a controllable state, and avoids local overheating or flameout caused by mismatch between air supply and combustion state.

[0022] Reference Figure 3As shown, the air distribution mechanism further includes a main air supply duct 7, multiple air distribution branch pipes 72, and a first regulating valve 73. The air inlet of the main air supply duct 7 is connected to an induced draft fan 71. The side air inlet 2 consists of side air distribution branch pipes 72 symmetrically arranged on both sides of the main firing section 13. Multiple air outlets facing into the kiln are opened on the side air distribution branch pipes 72. The top air inlet 3 is a top air distribution branch pipe 72 located at the top of the main firing section 13. The top air distribution branch pipe 72 extends along the length of the kiln body 1, and multiple air outlets are evenly opened at its bottom along the length direction. The bottom air inlet 4 is located at the top of the kiln body 1. The bottom air distribution branch pipe 72 has multiple upward-facing air outlets evenly distributed along its length at the top. The air inlets of the side air distribution branch pipe 72, the top air distribution branch pipe 72, and the bottom air distribution branch pipe 72 are all connected to the air outlet of the main air supply pipe 7. Each air distribution branch pipe 72 is equipped with a first regulating valve 73, which is an electric regulating valve used to independently control the air volume of each air distribution branch pipe 72. Through this graded control air distribution structure, the operator can flexibly adjust the air supply volume in each direction and position according to the temperature changes in different areas of the kiln, so as to achieve precise and flexible air distribution adjustment.

[0023] Reference Figure 2 As shown, the temperature monitoring unit further includes multiple temperature elements 5 installed within the kiln body 1. Specifically, the temperature elements 5 are thermocouples, and these thermocouples are distributed in the preheating section 11, the transition section 12, the main firing section 13, and the cooling section 14. Thermocouples are installed at three different heights (upper, middle, and lower) in the preheating section 11; a thermocouple is installed in the middle of the transition section 12; thermocouples are installed in five different areas (upper, middle, lower, left, and right) in the main firing section 13; and thermocouples are installed at two positions (upper and lower) in the cooling section 14. Each thermocouple is electrically connected to the central controller 6 to collect temperature signals from the corresponding section and transmit them to the central controller 6. This multi-point, multi-area temperature monitoring layout allows operators to monitor the temperature changes of the kiln body 1.

[0024] Reference Figures 1-2As shown, the cooling section 14 is further equipped with a waste heat recovery mechanism, which includes a heat collection hood 8 and a waste heat recovery pipe 81. Air circulation holes are provided on both sides of the cooling section 14. External air enters the cooling section 14 and comes into contact with the sintered coal gangue. The air is heated, forming a hot airflow that moves upward and enters the heat collection hood 8. The heat collection hood 8 is a circular hood with an inner diameter that gradually increases from bottom to top, located at the top of the cooling section 14, and is used to collect the high-temperature hot air generated by the cooling section 14. The air inlet of the waste heat recovery pipe 81 is connected to the air outlet of the heat collection hood 8. The air outlet extends into the interior of the preheating section 11 and connects to the waste heat inlet of the preheating section 11. This is used to guide the hot air from the cooling section 14 to the preheating section 11, thereby realizing the recycling of waste heat and reducing energy waste. A second regulating valve 82 is installed on the waste heat recovery pipe 81. The second regulating valve 82 is an electric regulating valve and is electrically connected to the central controller 6. The central controller 6 adjusts the opening of the second regulating valve 82 according to the temperature data of the preheating section 11, thereby controlling the amount of hot air introduced into the preheating section 11, avoiding excessive heat from causing the temperature of the preheating section 11 to be too high, and ensuring that the preheating process is stable and controllable.

[0025] The main firing section 13 is equipped with a flue gas sensor 9 electrically connected to the central controller 6. The flue gas sensor 9 is installed in the middle of the kiln wall of the main firing section 13 to collect real-time flue gas composition data of the main firing section 13, mainly including oxygen concentration and carbon monoxide concentration. The central controller 6 is electrically connected to the temperature monitoring unit, the flue gas sensor 9, and each of the first regulating valves 73 in the air distribution mechanism. The central controller 6 adopts a programmable logic controller or an industrial control computer. It has preset process parameters such as the target temperature range and oxygen concentration range of each section. Based on the received temperature data and flue gas composition data, it outputs control commands to each of the first regulating valves 73 to independently adjust the opening of the side air inlet 2, the top air inlet 3, and the bottom air inlet 4, thereby realizing the regulation of the air supply to different areas in the main firing section 13. Through dual monitoring and feedback regulation of temperature and flue gas composition, the kiln can always be in the best combustion state, which can ensure the full combustion of coal gangue and avoid heat loss due to excessive air supply.

[0026] The present invention also provides a sintering method for a self-heating segmented temperature-controlled sintering device for coal gangue, comprising the following steps: S1: Initial gradient preheating: Coal gangue is mixed evenly with clay and combustion aid in a certain proportion, pressed into shape by a molding machine and dried to a moisture content of ≤12% and stacked on a kiln car. The kiln car is sent into the preheating section 11 along the track. Hot air from the cooling section 14 is introduced into the preheating section 11 through the waste heat recovery pipe 81. The hot air temperature is between 200-300 degrees Celsius. Combined with the heat conducted by the main firing section 13, the coal gangue is preheated in a gradient. The preset preheating temperature is 500-750 degrees Celsius. The volatile matter generated during the preheating process is discharged through the volatile matter discharge outlet 111.

[0027] S2: Transition Buffer: After preheating, the coal gangue enters the transition section 12 with the kiln car. By adjusting the air volume of the auxiliary air inlets on both sides of the transition section 12, the temperature of the billet is smoothly transitioned within the transition section 12. The transition section 12 time is controlled at 0.5-1 hour, allowing the billet temperature to rise from the preset preheating temperature gradient to the preset firing start temperature, which is above 900 degrees Celsius. The temperature gradient within the transition section 12 is controlled at 50-80 degrees Celsius per meter to avoid thermal stress cracking of the billet due to a sudden temperature rise.

[0028] S3: Three-dimensional air distribution sintering: After the coal gangue enters the main sintering section 13, the central controller 6 independently adjusts the opening of the first regulating valve 73 on the side air inlet 2, top air inlet 3, and bottom air inlet 4 based on the temperature data of each area collected by the temperature monitoring unit and the flue gas composition data collected by the flue gas sensor 9. Air is supplied to the kiln from the side, top, and bottom of the coal gangue simultaneously, so that the oxygen concentration in the kiln is controlled within the range of 6%-8% and the carbon monoxide concentration is controlled below 500ppm. Sintering is carried out by spontaneous combustion of the combustible matter in the coal gangue. During the sintering process, the temperature of the main sintering section 13 is maintained within the preset sintering temperature range of 900-1000 degrees Celsius. When the temperature of a certain area exceeds 1050 degrees Celsius, the central controller 6 reduces the air supply to the corresponding area; when the temperature of a certain area is below 900 degrees Celsius, the central controller 6 increases the air supply to the corresponding area.

[0029] S4: Gradient Cooling: After sintering, the billet enters the cooling section 14 and air enters through air circulation holes on both sides of the cooling section 14 to achieve gradient cooling. During the cooling process, the hot air generated by the cooling section 14 is collected by the heat collection hood 8 located at the top of the cooling section 14. The hot air temperature is between 200-300 degrees Celsius. The hot air is directionally introduced into the preheating section 11 through the waste heat recovery pipe 81 to preheat the billet in the preheating section 11. The central controller 6 adjusts the opening of the second regulating valve 82 according to the temperature data of the preheating section 11 to control the amount of hot air introduced into the preheating section 11 and ensure that the temperature of the preheating section 11 is stable.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A self-heating, segmented temperature-controlled sintering device for coal gangue, comprising a kiln body (1), characterized in that, The kiln body (1) is sequentially configured along the coal gangue conveying direction as a preheating section (11), a transition section (12), a main firing section (13), and a cooling section (14), and also includes: The air distribution mechanism, which is set in the main firing section (13), includes side air inlets (2) distributed on both sides of the kiln body (1), top air inlets (3) set on the top of the kiln body (1), and bottom air inlets (4) set on the bottom of the kiln body (1). The side air inlets (2), top air inlets (3) and bottom air inlets (4) together constitute a three-dimensional air distribution structure surrounding the main firing section (13) inside the kiln body (1). Temperature monitoring unit, which includes multiple temperature elements (5) disposed in the kiln body (1); The central controller (6) is electrically connected to the temperature monitoring unit and the air distribution mechanism respectively, and is used to independently adjust the opening of the side air inlet (2), the top air inlet (3) and the bottom air inlet (4) according to the received temperature data.

2. The coal gangue self-heating segmented temperature-controlled sintering device according to claim 1, characterized in that, The air distribution mechanism also includes: The main air supply duct (7) has an exhaust fan (71) connected to its air inlet end. Multiple air distribution branch pipes (72) are connected to the side air inlet (2), the top air inlet (3) and the bottom air inlet (4), and the other end of each is connected to the air outlet of the main air supply pipe (7); The first regulating valve (73) is installed on the air distribution branch pipe (72) and is used to independently control the air volume of each air distribution branch pipe (72).

3. The coal gangue self-heating segmented temperature-controlled sintering device according to claim 1, characterized in that, The temperature measuring element is a thermocouple electrically connected to the central controller (6), and the thermocouple is distributed in the preheating section (11), the transition section (12), the main firing section (13) and the cooling section (14) to collect the temperature signals of the corresponding sections respectively.

4. The coal gangue self-heating segmented temperature-controlled sintering device according to claim 1, characterized in that, It also includes a waste heat recovery mechanism, which includes: A heat collection shroud (8) is disposed on top of the cooling section (14); The waste heat recovery pipe (81) has its air inlet end connected to the air outlet end of the heat collection hood (8), and the air outlet end extends into the interior of the preheating section (11) to direct the hot air from the cooling section (14) to the preheating section (11).

5. The coal gangue self-heating segmented temperature-controlled sintering device according to claim 4, characterized in that, The waste heat recovery pipe (81) is provided with a second regulating valve (82), which is connected to the central controller (6). The central controller (6) is connected to adjust the opening of the second regulating valve (82) according to the temperature data of the preheating section (11).

6. The coal gangue self-heating segmented temperature-controlled sintering device according to claim 1, characterized in that, The main firing section (13) is also equipped with a flue gas sensor (9) electrically connected to the central controller (6) for collecting flue gas composition data of the main firing section (13).

7. A sintering method for a self-heating, segmented temperature-controlled sintering device for coal gangue, characterized in that, The process is completed using a self-heating, segmented, temperature-controlled sintering device for coal gangue as described in any one of claims 1 to 6, comprising the following steps: S1: Initial gradient preheating: The coal gangue is fed into the preheating section (11) and preheated in the preheating section (11) so that the billet temperature gradually rises to the preset preheating temperature. S2: Transition buffer: The preheated coal gangue enters the transition section (12), and the temperature transition is achieved in the transition section (12), so that the temperature of the billet rises from the preset preheating temperature gradient to the preset firing start temperature. S3: Three-dimensional air distribution sintering: When the coal gangue enters the main sintering section (13), the central controller (6) independently adjusts the opening of the side air inlet (2), the top air inlet (3) and the bottom air inlet (4) according to the temperature data collected by the temperature monitoring unit, and supplies air into the kiln from the side, top and bottom of the coal gangue at the same time, controls the spontaneous combustion of the combustibles in the coal gangue for sintering, so that the temperature of the main sintering section (13) is maintained within the preset sintering temperature range; S4: Gradient cooling: The sintered billet enters the cooling section (14) and is cooled in the cooling section (14) to obtain the finished product.

8. The sintering method of a self-heating, segmented temperature-controlled sintering device for coal gangue according to claim 7, characterized in that, In step S3, the central controller (6) also adjusts the opening of the side air inlet (2), top air inlet (3) and bottom air inlet (4) based on the flue gas composition data collected by the flue gas sensor (9) set in the main firing section (13) to control the oxygen concentration and / or carbon monoxide concentration in the main firing section (13) within a preset range.

9. The sintering method of a self-heating, segmented temperature-controlled sintering device for coal gangue according to claim 7, characterized in that, In step S4, when the coal gangue is cooled in the cooling section (14), the hot air generated in the cooling section (14) is collected by the heat collection cover (8) set at the top of the cooling section (14). The hot air is directionally introduced into the preheating section (11) through the waste heat recovery pipe (81) to preheat the billet in the preheating section (11).

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