A multi-point cyclic combustion system

Abstract

The present invention discloses a multi-point circulating combustion system, which includes a plurality of kilns. Adjacent kilns are connected through pipelines, and valves are provided on the pipelines between adjacent kilns to realize the opening and closing of the corresponding pipelines. Exhaust pipes are provided between all kilns and the gas collecting box to realize the separate connection between the gas collecting box and a single kiln. In the present invention, each kiln body is interconnected. During roasting, the tail gas passes through the connected kiln bodies filled with raw materials according to a certain process design and then is discharged, so as to utilize the waste heat of the tail gas to preheat the raw ore in the adjacent kiln, greatly saving energy consumption, and thus achieving the purpose of energy conservation and consumption reduction.

Description

Technical Field

[0001] The present invention relates to the technical field of roasting processes, and specifically to a multi-point circulating combustion system. Background Art

[0002] A tunnel kiln is a kiln similar to a tunnel made of refractory materials, thermal insulation materials, and building materials, with carrier tools such as kiln cars installed inside. It is a thermal processing equipment for continuous firing in the prior art. Tunnel kilns are widely used in the roasting production of ceramic products and are also applied in metallurgical industries such as abrasives.

[0003] A tunnel kiln is generally a long straight tunnel with fixed walls and arches on both sides and at the top, and a track is laid at the bottom on which the kiln cars run. Combustion equipment is installed on both sides in the middle of the tunnel kiln, forming a fixed high-temperature zone - the firing zone. The high-temperature flue gas generated by combustion flows along the tunnel towards the kiln head under the action of the chimney or induced draft fan at the front end of the tunnel kiln, and at the same time gradually preheats the products entering the kiln. This section constitutes the preheating zone of the tunnel kiln. Cold air is blown into the tail of the tunnel kiln to cool the products in the latter section of the tunnel kiln. After the blown cold air flows through the products and is heated, it is then extracted and sent to the dryer as the heat source for drying green blanks. This section constitutes the cooling zone of the tunnel kiln. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-point circulating combustion system, with a completely different design concept, to overcome the disadvantages of the existing tunnel kiln in actual production, such as multiple processes, high requirements for equipment, and large pollution.

[0005] The present invention overcomes the above technical problems by adopting the following technical solutions, specifically:

[0006] A multi-point circulating combustion system includes multiple kilns, which are connected by pipelines between adjacent kilns, and valves are provided on the pipelines between adjacent kilns to realize the opening and closing of the corresponding pipelines;

[0007] A gas collecting box, exhaust pipes are provided between all kilns and the gas collecting box to realize the separate connection between the gas collecting box and a single kiln. Opening and closing valves are provided on each exhaust pipe. The opening and closing valves are closed when the corresponding kiln is in the ignition state and opened in other states, so as to realize the waste gas of the kiln in the ignition state to preheat the raw materials through other kilns.

[0008] As a further solution of the present invention: The kilns are connected by pipelines to form a closed-loop structure.

[0009] As a further solution of the present invention: A raw material input belt and a gas input pipe are respectively provided on one side of the kiln, and the raw material input belt and the gas input pipe are respectively connected to the corresponding kiln.

[0010] As a further solution of the present invention: a bag filter is provided at the tail of the air collecting box to realize the treatment and emission of the tail gas.

[0011] As a further solution of the present invention: the kiln includes a matrix with an overall cavity structure, the upper end of the matrix is a kiln top cover structure, and a discharge port is provided at the center of the bottom of the matrix;

[0012] As a further solution of the present invention: the inside of the matrix is a hollow structure for storing raw materials, wherein the upper part of the hollow structure is a cylindrical cavity structure surrounded by refractory bricks, and the lower part of the hollow structure is an inverted cone cavity structure filled with refractory castable;

[0013] As a further solution of the present invention: air extraction ports are symmetrically arranged on both sides of the lower part of the matrix, and the air extraction ports are communicated with corresponding pipelines;

[0014] As a further solution of the present invention: an air extraction channel is provided at the lower part of the matrix, the inner interface of the air extraction channel is communicated with the inverted cone cavity structure, and the outer interface of the air extraction channel is communicated with the corresponding air extraction port;

[0015] As a further solution of the present invention: the air extraction channel includes a horizontal air extraction channel and an inclined air extraction channel, and an annular channel is provided in the refractory castable at the outer interfaces of the horizontal air extraction channel and the inclined air extraction channel, and the annular channel is communicated with the corresponding air extraction port;

[0016] As a further solution of the present invention: an observation hole is provided on the outer side of the matrix at the position corresponding to the horizontal air extraction channel to realize real-time observation of the roasting situation of the raw materials in the kiln through the observation hole and the horizontal air extraction channel;

[0017] As a further solution of the present invention: the inclined air extraction channel is a channel structure with a lower inner part and a higher outer part, which can effectively avoid the outflow of raw materials and can also make the heat fill the raw materials for sufficient roasting;

[0018] As a further solution of the present invention: a plurality of air inlet ports are evenly arranged in the middle of the matrix, a preheating air duct is provided between the matrix and the refractory bricks, a horizontal air inlet duct is provided at the upper end of the refractory bricks, the horizontal air inlet duct communicates the preheating air duct and the cylindrical cavity structure surrounded by the refractory bricks, and an annular air duct is provided between the air inlet ports and the preheating air duct to realize their connection;

[0019] As a further solution of the present invention: the kiln top cover structure includes a raw material inlet provided in the middle of the kiln top cover structure, an air extraction and exhaust port is provided on the kiln top cover structure on one side of the raw material inlet, the air extraction and exhaust port is connected to the corresponding exhaust pipe, an air inlet port one and a fuel inlet port are respectively provided on the kiln top cover structure, and the fuel inlet port is connected to the corresponding gas input pipe;

[0020] As a further solution of the present invention: the air inlet direction of the fuel inlet is the tangential direction of the kiln top cover structure, so that the gas flows into the base in a ring shape through the fuel inlet;

[0021] As a further solution of the present invention: the first air inlets are symmetrically distributed at the top of the kiln top cover structure, and the same number of jet nozzles as the first air inlets are arranged on the inner bottom surface of the kiln top cover structure. The nozzles of the jet nozzles are vertically downward, and a hot air exchanger is arranged between the jet nozzles and the corresponding first air inlets to realize communication with each other;

[0022] As a further solution of the present invention: the hot air exchanger is of an overall cavity structure and is arranged in the kiln top cover structure. A partition is arranged in the cavity structure so that the hot air exchanger forms a zigzag channel, so that the air is preheated when entering from the jet nozzle.

[0023] As a further solution of the present invention: the gas collecting box is of an overall cylindrical structure. An air inlet is arranged at the top of the gas collecting box, and the air inlet is connected to the corresponding exhaust pipe. An induced draft fan is arranged on the outer side of the lower part of the gas collecting box, and the exhaust port of the induced draft fan is communicated with the bag filter;

[0024] As a further solution of the present invention: at least two induced draft fans are arranged and symmetrically distributed on the outer side of the lower part of the gas collecting box;

[0025] As a further solution of the present invention: the air inlets are symmetrically distributed around the top of the gas collecting box;

[0026] As a further solution of the present invention: a flow guiding column is arranged in the middle of the gas collecting box, and an air guiding pipe is arranged at the air inlet end of the induced draft fan. The pipe orifice direction of the air guiding pipe is the tangential direction of the gas collecting box structure, and the air guiding pipe cooperates with the flow guiding column to realize spiral flow of the gas in the gas collecting box and keep the air pressure at each air inlet uniform and stable.

[0027] Compared with the prior art, the advantages of the present invention compared with the prior art are as follows:

[0028] 1. Less equipment investment and low maintenance cost: Compared with the tunnel kiln, there is no need for brick-making systems and equipment such as kiln cars, kiln car tracks, and towing trailers. Moreover, the kiln car basically needs to be maintained every time it is used, and the maintenance cost is relatively high. In this application, belt transportation is used for feeding, and a trolley is used for discharging, which is convenient, fast, and easy to maintain;

[0029] 2. Obvious environmental protection and energy-saving effects: Because the waste gas waste heat is fully utilized before being discharged, the heat utilization rate is high and the heat loss is small;

[0030] 3. Fewer workers and low labor cost: Under the same production capacity, the labor cost is saved by more than 60% compared with the tunnel kiln;

[0031] 4. Low labor intensity and good working environment: the production process is greatly reduced, the manual operation link is basically eliminated, and the dusty working environment is fundamentally improved;

[0032] 5. Strong adaptability of raw materials: As the raw material bauxite used is a non-renewable resource, the raw materials are becoming increasingly scarce, especially the supply of high-grade bauxite is decreasing and the price is high. This overcomes the quality problems such as "car collapse" when using high-iron bauxite in the tunnel kiln, which leads to the inability to burn through and burn through the middle part. It can adapt to different grades of bauxite, which plays a significant role in the adaptability of the raw material market and the reduction of production costs;

[0033] 6. Raw ore (raw materials) directly enters the kiln through a belt conveyor (raw material conveyor belt). Each kiln body is connected to each other. During roasting, the tail gas passes through the connected kiln body filled with raw materials (raw materials) according to a certain process design and then is discharged. The waste heat of the tail gas is used to preheat the raw ore (raw materials) in the connected kiln, which greatly saves energy consumption and achieves the purpose of energy saving and consumption reduction.

[0034] 7. The dust removal system uses a bag dust collector and uses a back-blowing blower for dust removal, which has a good dust removal effect and the dust powder is recovered for processing and utilization;

[0035] 8. The burned ore directly enters the insulation equipment for insulation after passing through the discharge trolley, which greatly reduces heat loss and reduces smelting energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0037] Figure 1 It is a schematic diagram of the structure of the present invention;

[0038] Figure 2 for Figure 1 The main view;

[0039] Figure 3 It is the installation schematic diagram of the present invention;

[0040] Figure 4 It is a structural schematic diagram of the kiln in the present invention;

[0041] Figure 5 for Figure 4 The main view;

[0042] Figure 6 for Figure 5 AA section view;

[0043] Figure 7 for Figure 6 BB cross-sectional view;

[0044] Figure 8 This is the kiln top cover structure in the present invention;

[0045] Figure 9 It is Figure 8 the top view of;

[0046] Figure 10 It is Figure 9 the partial sectional view of;

[0047] Figure 11 This is the structural schematic diagram of the gas collecting box in the present invention;

[0048] Figure 12 It is Figure 11 of Figure 11 the top view of.

[0049] In the figure: 1 - kiln, 2 - pipeline, 3 - gas collecting box, 4 - exhaust pipe, 5 - raw material input belt, 6 - gas input pipe, 7 - bag filter, 8 - opening and closing valve, 9 - valve, 11 - matrix, 12 - kiln top cover structure, 13 - air extraction port, 14 - discharge port, 15 - horizontal air extraction channel, 16 - inclined air extraction channel, 17 - annular channel, 18 - fuel inlet, 19 - air inlet, 20 - jet port, 21 - hot air exchanger, 22 - induced draft fan, 23 - air outlet, 24 - air draft pipe, 25 - guide post, 31 - air inlet, 110 - refractory brick, 111 - refractory castable, 112 - preheating air duct, 113 - horizontal air inlet duct, 114 - annular air duct, 115 - raw material inlet, 116 - air extraction and exhaust port, 117 - air inlet one, 118 - observation hole. Detailed implementation manners

[0050] For the convenience of understanding the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0051] In addition, an element in the present invention is referred to as being "fixed to" or "disposed on" another element, and it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "front", "rear" and similar expressions used herein are only for the purpose of illustration and do not represent the only embodiments.

[0052] Please refer to Figures 1 to 12, in the embodiments of the present invention, a multi-point circulating combustion system includes a plurality of kilns 1, and adjacent kilns 1 are connected through pipelines 2. Valves 9 are provided on the pipelines 2 between adjacent kilns 1 to realize the opening and closing of the corresponding pipelines 2;

[0053] A gas collecting box 3. Exhaust pipes 4 are provided between all the kilns 1 and the gas collecting box 3 to realize the separate connection between the gas collecting box 3 and a single kiln 1. An opening and closing valve 8 is provided on each exhaust pipe 4. The opening and closing valve 8 is closed when the corresponding kiln is in the ignition state and is opened in other states, so as to realize the waste gas of the kiln in the ignition state to preheat the raw materials through other kilns; The kilns 1 are connected through pipelines 2 to form a closed-loop structure; A raw material input belt 5 and a gas input pipe 6 are respectively provided on one side of the kiln 1, and the raw material input belt 5 and the gas input pipe 6 are respectively connected to the corresponding kiln 1; A bag filter 7 is provided at the tail of the gas collecting box 3 to realize the treatment and discharge of the tail gas.

[0054] The kiln 1 includes a base body 11 with an overall cavity structure. The upper end of the base body 11 is a kiln top cover structure 12, and a discharge port 14 is provided at the center of the bottom of the base body 11; The inside of the base body 11 is a hollow structure for storing raw materials. The upper part of the hollow structure is a cylindrical cavity structure surrounded by refractory bricks 110, and the lower part of the hollow structure is an inverted cone cavity structure filled with refractory castable 111; Exhaust ports 13 are symmetrically provided on both sides of the lower part of the base body 11, and the exhaust ports 13 are connected to the corresponding pipelines 2; An exhaust channel is provided at the lower part of the base body 11. The inner interface of the exhaust channel is connected to the inverted cone cavity structure, and the outer interface of the exhaust channel is connected to the corresponding exhaust port 13; The exhaust channel includes a horizontal exhaust channel 15 and an inclined exhaust channel 16. An annular channel 17 is provided in the refractory castable at the outer interfaces of the horizontal exhaust channel 15 and the inclined exhaust channel 16, and the annular channel 17 is connected to the corresponding exhaust port 13; An observation hole 118 is provided on the outer side of the base body 11 at a position corresponding to the horizontal exhaust channel 15, so as to realize the real-time observation of the roasting situation of the raw materials in the kiln through the observation hole 118 and the horizontal exhaust channel 15; The inclined exhaust channel 16 is a channel structure with a lower inner part and a higher outer part, which can effectively prevent the outflow of raw materials and can also realize the filling of heat in the raw materials and sufficient roasting; A plurality of air inlets 19 are evenly arranged in the middle of the base body 11. A preheating air duct 112 is provided between the base body 11 and the refractory bricks 110. A horizontal air inlet duct 113 is provided at the upper end of the refractory bricks 110. The horizontal air inlet duct 113 connects the preheating air duct 112 and the cylindrical cavity structure surrounded by the refractory bricks 110. An annular air duct 114 is provided between the air inlets 19 and the preheating air duct 112 to realize the connection between them;

[0055] The kiln top cover structure 12 includes a raw material inlet 115 provided in the middle of the kiln top cover structure 12. An air extraction and exhaust port 116 is provided on the kiln top cover structure 12 on one side of the raw material inlet 115. The air extraction and exhaust port 116 is connected to the corresponding exhaust pipe 4. An air inlet 117 and a fuel inlet 18 are respectively provided on the kiln top cover structure 12. The fuel inlet 18 is connected to the corresponding gas input pipe 6. The air inlet direction of the fuel inlet 18 is the tangential direction of the kiln top cover structure 12, so that the gas flows into the matrix 11 in a ring shape through the fuel inlet 18. The air inlets 117 are symmetrically distributed around the top of the kiln top cover structure 12. The same number of jet nozzles 20 as the air inlets 117 are provided on the inner bottom surface of the kiln top cover structure 12. The nozzles of the jet nozzles 20 are vertically downward. A hot air exchanger 21 is provided between the jet nozzles 20 and the corresponding air inlets 117 to achieve communication therebetween. The hot air exchanger 21 is a cavity structure as a whole and is provided in the kiln top cover structure 12. A partition is provided in the cavity structure so that the hot air exchanger 21 forms a zigzag channel, so that the air is preheated when entering from the jet nozzles 20.

[0056] The gas collecting box 3 is a columnar cylindrical structure as a whole. An air inlet 31 is provided at the top of the gas collecting box 3. The air inlet 31 is connected to the corresponding exhaust pipe 4. An induced draft fan 22 is provided on the outer side of the lower part of the gas collecting box 3. The exhaust port 23 of the induced draft fan 22 is communicated with the bag filter 7.

[0057] At least two induced draft fans 22 are provided and are symmetrically distributed on the outer side of the lower part of the gas collecting box 3. The air inlets 31 are symmetrically distributed around the top of the gas collecting box 3. A flow guiding column 25 is provided in the middle of the gas collecting box 3. An air guiding pipe 24 is provided at the air inlet end of the induced draft fan 22. The pipe orifice direction of the air guiding pipe 24 is the tangential direction of the structure of the gas collecting box 3. The air guiding pipe 24 cooperates with the flow guiding column 25 to make the gas in the gas collecting box 3 flow in a spiral shape and keep the air pressure at each air inlet 31 uniform and stable.

[0058] During specific use; in this embodiment, one of the kilns C is used for roasting abrasives, and another adjacent kiln D is used for preheating raw materials (raw bauxite) to introduce the working principle of this embodiment;

[0059] First, close all the valves 9 in this embodiment to isolate each kiln 1 from each other independently. Close the corresponding air inlet 19, the first air inlet 117, the observation hole 118, and the discharge port 14 on the kiln 1. Then start feeding. In this embodiment, a crushing system is used to crush the raw material (i.e., bauxite) so that its size meets the roasting requirements. The crushing system in this embodiment uses a 55KW motor and a 500×750 crusher. Then, a feeding system is used to feed the two kilns 1 respectively. The feeding system in this embodiment uses an 80cm belt conveyor for conveying and feeding, which has a large transportation capacity and is easy to maintain. At the same time, the existing conventional technology is used to quantitatively input the raw material to ensure that the weight of the raw material in the two kilns 1 meets the production regulations.

[0060] After the raw material input is completed, close the raw material feeding ports 115 on the kilns respectively. At this time, close the opening and closing valve 8 of the exhaust pipe 4 connected to the kiln C that needs to be roasted, and open the opening and closing valve 8 of the exhaust pipe 4 connected to the kiln D that needs to be preheated. Open the valve 9 on the pipeline 2 between the kiln C and the kiln D, and start the induced draft fan 22. Open the first air inlet 117 on the kiln C. Then, under the action of the induced draft fan 22, the air flow direction is: the first air inlet 117 on the kiln C - the kiln C - the pipeline 2 - the kiln D - the exhaust pipe 4 connected to the kiln D - the gas collecting box 3 - the bag filter 7. Input natural gas into the kiln C through the gas input pipe 6, and ignite the kiln C to start roasting the raw material (bauxite). At this time, the valve 9 between the kiln C and the kiln D has been opened. Since the intake direction of the fuel inlet 18 (the flow direction of natural gas) is the tangential direction of the kiln top cover structure 12, the gas flows into the matrix 11 in a ring shape through the fuel inlet 18, and the nozzle of the jet port 20 is vertically downward. That is, the high-temperature gas flow of the mixture of air and natural gas flows downward in a spiral shape into the raw material (bauxite) in the kiln C to continuously roast the raw material. Under the action of the induced draft fan 22, the tail gas (with residual temperature and containing a large amount of dust or impurities) flowing out from the bottom of the kiln C flows into the bottom of the kiln D through the pipeline 2. After flowing through all the raw materials in the kiln D, it flows into the gas collecting box 3 through the exhaust pipe 4 and is finally discharged after being treated by the bag filter 7. At this time, the residual temperature of the tail gas has fully preheated the raw material in the kiln D, and the impurities containing useful solid or mist components such as corundum in the tail gas will also be deposited in the kiln D, while the remaining pollutants will be treated by the bag filter 7.

[0061] Among them, natural gas flows into the kiln C in a tangential and annular direction, while air flows into the kiln C vertically downward. Then, the natural gas and air are mixed evenly, enabling sufficient combustion. Moreover, under the action of the air flow direction, the high-temperature gas generated after combustion will integrally immerse into the raw materials in the kiln C in a spiral downward manner, making the raw materials used in the kiln C roasted sufficiently and heated evenly, and preventing quality problems such as the middle part of the raw materials in the tunnel kiln not being burned through or cooked. Additionally, air extraction channels (horizontal air extraction channel 15 and inclined air extraction channel 16) are evenly arranged at the bottom of the kiln C, and the air extraction channels are connected through an annular channel 17 and connected to the pipeline 2, achieving consistent and stable negative pressure at each air extraction channel. Then, the high-temperature gas will flow into the raw materials in a spiral downward manner with the same negative pressure on each cross-section of the kiln C, making the raw materials roasted sufficiently and uniformly.

[0062] When the air input is insufficient during the roasting process, the air inlet 19 in the middle of the kiln C is opened at this time. Since the kiln C already has a high temperature at this time, when the air passing through the air inlet 19 passes through the pre-annular air duct 114 and the preheating air duct 112, the high temperature of the kiln C preheats the air, enabling more efficient combustion. Among them, the hot air exchanger 21 located on the kiln top cover structure 12 is also to increase the contact time between the air and the kiln C to preheat the air flowing through, achieving efficient combustion. After the roasting is completed, the discharge port 14 at the bottom of the kiln C is opened, and the roasted cooked ore directly enters the heat preservation equipment for heat preservation after passing through the discharge trolley, greatly reducing heat loss and reducing smelting energy consumption.

[0063] The horizontal air extraction channel 15 corresponds to the position of the observation hole 118, and the roasting situation of the raw materials in the kiln C can be observed in real time through the observation hole 118 and the horizontal air extraction channel 15. In the later stage, when cleaning the kiln C or discharging the loose raw materials, it can also be achieved through the channel composed of the observation hole 118 and the horizontal air extraction channel 15.

[0064] The above is the whole process of roasting a single kiln and preheating an adjacent kiln. The working principles of roasting multiple kilns and their corresponding kiln preheating are the same as the above-described process, and this application will not be repeated here.

[0065] During the roasting of multiple kilns and the preheating of the kilns, since the pipe orifice direction of the air duct 24 in the air collecting box 3 is the tangential direction of the air collecting box 3 structure, the air duct 24 cooperates with the guide column 25 to enable the gas in the air collecting box 3 to flow in a spiral shape and maintain uniform and stable air pressure at each air inlet 31; that is, the above structural design of the air collecting fan 3 makes the negative pressure intensity in the exhaust pipe 4 communicated with and opened by the air collecting box 3 the same, ensuring that the heat energy intensity and flow velocity in the roasted kilns are in the same state, and ensuring the roasting efficiency and quality of the roasted kilns used.

[0066] In this embodiment, the matrix 11, the kiln top cover structure 12, the air collecting box 3, the support body and the corresponding pipelines are all made of steel. The refractory bricks 110 and refractory castables 111 inside the matrix 11 are made of existing conventional high-temperature refractory materials.

[0067] In the production of this embodiment, except for the dust prevention process in the crushing system link, the rest of the processes are carried out in a closed environment, and basically no additional dust will be generated at the production site. At the same time, whether it is raw material transportation or the roasting process, the operators do not need to work in a high-temperature environment, which greatly improves the working environment. If the conditions of the enterprise permit, all the control environments in this embodiment can be uniformly replaced by existing intelligent control components, and then fully automatic production can be realized, which is efficient, fast and reduces production safety risks.

[0068] The number of kilns and the layout relationship with the air collecting fans in the attached drawings of this embodiment are only one of them. The production unit can make specific layouts according to reasons such as the size of the production site, the scale of the enterprise, and the investment cost. In this embodiment, 20 kilns are used and connected in series by pipelines 2 to form a ring, and the air collecting box 3 is arranged in the middle of the ring, which reduces the on-site land use and the length of the pipelines 2. At the same time, this embodiment can achieve the highest production efficiency of roasting 10 spaced kilns simultaneously and preheating the other 10 spaced kilns simultaneously.

[0069] The above is only an illustration of the best embodiment of the present invention, but it should not be construed as a limitation to the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to vary. Any changes made within the protection scope of the independent claims of the present invention are within the protection scope of the present invention.

[0070] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

Claims

1. A multi-point circulating combustion system, characterized in that: It includes a plurality of kilns (1), and adjacent kilns (1) are connected through pipelines (2). Valves (9) are provided on the pipelines (2) between adjacent kilns (1) to realize the opening and closing of the corresponding pipelines (2); A gas collecting box (3), exhaust pipes (4) are provided between all the kilns (1) and the gas collecting box (3) to realize the separate connection between the gas collecting box (3) and a single kiln (1). Opening and closing valves (8) are provided on each exhaust pipe (4); The kiln (1) includes a base body (11) with an overall cavity structure. The upper end of the base body (11) is a kiln top cover structure (12), and a discharge port (14) is provided at the center of the bottom of the base body (11); The interior of the base body (11) is a hollow structure for storing raw materials. The upper part of the hollow structure is a cylindrical cavity structure surrounded by refractory bricks (110), and the lower part of the hollow structure is an inverted cone cavity structure filled with refractory castable (111); Air extraction ports (13) are symmetrically arranged on both sides of the lower part of the base body (11), and the air extraction ports (13) are connected to the corresponding pipelines (2); An air extraction channel is provided at the lower part of the base body (11). The inner interface of the air extraction channel is connected to the inverted cone cavity structure, and the outer interface of the air extraction channel is connected to the corresponding air extraction port (13); The air extraction channel includes a horizontal air extraction channel (15) and an inclined air extraction channel (16). An annular channel (17) is provided in the refractory castable at the outer interfaces of the horizontal air extraction channel (15) and the inclined air extraction channel (16), and the annular channel (17) is connected to the corresponding air extraction port (13); An observation hole (118) is provided on the outer side of the base body (11) at a position corresponding to the horizontal air extraction channel (15) to realize the real-time observation of the roasting situation of the raw materials in the kiln through the observation hole (118) and the horizontal air extraction channel (15); The inclined air extraction channel (16) is a channel structure with a lower inner part and a higher outer part, which can effectively prevent the outflow of raw materials and can also make the heat fill the raw materials for sufficient roasting; A plurality of air inlets (19) are evenly arranged in the middle of the base body (11). A preheating air duct (112) is provided between the base body (11) and the refractory bricks (110). A horizontal air duct (113) is provided at the upper end of the refractory bricks (110). The horizontal air duct (113) connects the preheating air duct (112) and the cylindrical cavity structure surrounded by the refractory bricks (110). An annular air duct (114) is provided between the air inlets (19) and the preheating air duct (112) to realize their connection; The kiln top cover structure (12) includes a raw material inlet (115) provided in the middle of the kiln top cover structure (12). A gas extraction and exhaust port (116) is provided on the kiln top cover structure (12) on one side of the raw material inlet (115). The gas extraction and exhaust port (116) is connected to the corresponding exhaust pipe (4). An air inlet one (117) and a fuel inlet (18) are respectively provided on the kiln top cover structure (12), and the fuel inlet (18) is connected to the corresponding gas input pipe (6); The air inlet direction of the fuel inlet (18) is the tangential direction of the kiln top cover structure (12), so that the fuel gas flows into the matrix (11) in a ring shape through the fuel inlet (18); The first air inlets (117) are symmetrically distributed around the top of the kiln top cover structure (12). The same number of jet nozzles (20) as the first air inlets (117) are arranged on the inner bottom surface of the kiln top cover structure (12). The nozzles of the jet nozzles (20) face vertically downward. A hot air exchanger (21) is arranged between the jet nozzles (20) and the corresponding first air inlets (117) to achieve communication therebetween; The hot air exchanger (21) is of an overall cavity structure and is arranged in the kiln top cover structure (12). A partition is arranged in the cavity structure so that the hot air exchanger (21) forms a zigzag channel, so that the air is preheated when entering from the jet nozzles (20); The kilns (1) are connected through pipes (2) to form a closed-loop structure.

2. The multi-point cyclic combustion system according to claim 1, characterized in that: A raw material input belt (5) and a fuel gas input pipe (6) are respectively arranged on one side of the kiln (1), and the raw material input belt (5) and the fuel gas input pipe (6) are respectively connected to the corresponding kiln (1).

3. A multi-point cyclic combustion system according to claim 1, characterized in that: A bag filter (7) is arranged at the tail of the gas collecting box (3) to realize the treatment and discharge of the tail gas.

4. A multi-point cyclic combustion system according to claim 1, characterized in that: The gas collecting box (3) is of an overall cylindrical structure. An air inlet (31) is arranged at the top of the gas collecting box (3). The air inlet (31) is connected to the corresponding exhaust pipe (4). An induced draft fan (22) is arranged on the outer side of the lower part of the gas collecting box (3). The exhaust port (23) of the induced draft fan (22) is connected to the bag filter (7); There are at least two induced draft fans (22), and they are symmetrically distributed on the outer side of the lower part of the gas collecting box (3); The air inlets (31) are symmetrically distributed around the top of the gas collecting box (3); A flow guiding column (25) is arranged in the middle of the gas collecting box (3). An air guiding pipe (24) is arranged at the air inlet end of the induced draft fan (22). The pipe orifice direction of the air guiding pipe (24) is the tangential direction of the structure of the gas collecting box (3). The air guiding pipe (24) cooperates with the flow guiding column (25) to realize the spiral flow of the gas in the gas collecting box (3) and keep the air pressure at each air inlet (31) uniform and stable.

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