Kiln structure of a multi-point circulating combustion system

Abstract

The present invention discloses a kiln structure of a multi-point circulating combustion system, including a kiln. The kiln includes a matrix with an overall cavity structure, the upper end of which is a kiln top cover structure, and a discharge port is arranged at the center of the bottom of the matrix; the interior 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; 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; an air extraction channel is arranged 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. In the structure of the present invention, the high-temperature air flow inside will spiral downward into the raw materials at the same negative pressure on each cross-section of the kiln, so that the raw materials are fully and uniformly roasted.

Description

Technical Field

[0001] The present invention relates to the technical field of roasting processes, and specifically to a kiln structure of 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 arch roofs on both sides and at the top, and kiln cars running on the tracks laid at the bottom. 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 kiln tail 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 kiln structure of a multi-point circulating combustion system, with a completely different design concept, to overcome the disadvantages of existing tunnel kilns 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 kiln structure of a multi-point circulating combustion system includes a kiln. The kiln includes a base with an overall cavity structure, the upper end of the base is a kiln top cover structure, and a discharge port is provided in the center of the bottom of the base;

[0007] As a further solution of the present invention: The interior of the base is a hollow structure for storing raw materials. Among them, 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;

[0008] As a further solution of the present invention: Air extraction ports are symmetrically arranged on both sides of the lower part of the base, and the air extraction ports are connected to corresponding pipelines;

[0009] As a further solution of the present invention: An air extraction channel is provided in the lower part of the base. 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.

[0010] 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 arranged in the refractory castable at the outer interfaces of the horizontal air extraction channel and the inclined air extraction channel, and the annular channel communicates with the corresponding air extraction port.

[0011] As a further solution of the present invention: an observation hole is arranged on the outer side of the matrix at the position corresponding to the horizontal air extraction channel, so as to realize real-time observation of the raw material roasting situation in the kiln through the observation hole and the horizontal air extraction channel.

[0012] As a further solution of the present invention: the inclined air extraction channel is a channel structure with a lower inner side and a higher outer side, which can effectively avoid the outflow of raw materials and can also make the heat fill the raw materials, and the roasting is sufficient.

[0013] As a further solution of the present invention: a plurality of air inlets are evenly arranged in the middle of the matrix, a preheating air duct is arranged between the matrix and the refractory brick, a horizontal air inlet duct is arranged at the upper end of the refractory brick, the horizontal air inlet duct communicates the preheating air duct and the cylindrical cavity structure surrounded by the refractory brick, and an annular air duct is arranged between the air inlet and the preheating air duct to realize mutual communication.

[0014] As a further solution of the present invention: the kiln top cover structure includes a raw material inlet arranged in the middle of the kiln top cover structure, an air extraction and exhaust port is arranged 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 one and a fuel inlet are respectively arranged on the kiln top cover structure, and the fuel inlet is connected to the corresponding gas input pipe;

[0015] 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 matrix in a ring shape through the fuel inlet;

[0016] As a further solution of the present invention: the air inlets one are symmetrically distributed at the top of the kiln top cover structure, and the same number of jet ports as the air inlets one are arranged on the inner bottom surface of the kiln top cover structure, the nozzles of the jet ports are vertically downward, and a hot air exchanger is arranged between the jet ports and the corresponding air inlets one to realize mutual communication;

[0017] As a further solution of the present invention: the hot air exchanger is a cavity structure as a whole and is arranged in the kiln top cover structure, and 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 port.

[0018] Compared with the prior art, the advantages of the present invention compared with the prior art are as follows:

[0019] 1. The intake 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 through the fuel inlet, and the nozzle of the jet port is vertically downward. That is, the high-temperature gas flow of the air-natural gas mixed combustion flows downward in a spiral into the raw materials in the kiln, and continuously roasts the raw materials.

[0020] 2. The overall high-temperature gas flow generated after combustion will immerse into the raw materials in the kiln in a spiral downward manner, so that the raw materials used in the kiln are roasted sufficiently and heated evenly, and quality problems such as the middle part of the raw materials in the tunnel kiln not being burned through or cooked will not occur. Moreover, air extraction channels (horizontal air extraction channels and inclined air extraction channels) are evenly arranged at the bottom of the kiln, and the air extraction channels are connected through an annular channel and connected to a pipeline, so that the negative pressure at each air extraction channel is consistent and stable. Then the high-temperature gas flow will flow downward into the raw materials in a spiral with the same negative pressure on each cross-section of the kiln, making the raw materials roasted sufficiently and uniformly.

[0021] 3. When the air input is insufficient during the roasting process, the air inlet in the middle of the kiln 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 passes through the pre-annular air duct and the preheating air duct, the high temperature of the kiln preheats the air, and then it can burn more efficiently.

[0022] 4. The hot air exchanger located on the kiln top cover structure is also to increase the contact time between the air and the kiln to preheat the air flowing through and achieve efficient combustion.

[0023] 5. After the roasting is completed, the discharge port at the bottom of the kiln 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.

[0024] 6. The horizontal air extraction channel corresponds to the position of the observation hole, and the roasting situation of the raw materials in the kiln can be observed in real time through the observation hole and the horizontal air extraction channel. In the later stage, when cleaning the kiln or discharging the loose raw materials, it can also be achieved through the channel composed of the observation hole and the horizontal air extraction channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The 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 to the present invention. In the drawings:

[0026] Figure 1 is a schematic structural diagram of the present invention;

[0027] Figure 2 is Figure 1 the front view of;

[0028] Figure 3 is Figure 2 the A-A cross-sectional view of;

[0029] Figure 4 is Figure 3 the sectional view taken along line B-B;

[0030] Figure 5 is the kiln top cover structure in the present invention;

[0031] Figure 6 is Figure 5 the top view;

[0032] Figure 7 is Figure 6 the partial sectional view;

[0033] Figure 8 is the structural schematic diagram of the multi-point circulating combustion system applied in the present invention;

[0034] Figure 9 is Figure 8 the front view;

[0035] Figure 10 is the installation schematic diagram of the multi-point circulating combustion system;

[0036] Figure 11 is the structural schematic diagram of the gas collecting box in the multi-point circulating combustion system;

[0037] Figure 12 is Figure 11 of Figure 11 the top view.

[0038] 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 discharge port, 24 - induced draft pipe, 25 - guide column, 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 feed port, 116 - air extraction and exhaust port, 117 - air inlet one, 118 - observation hole. Detailed implementation manners

[0039] To facilitate the understanding of 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.

[0040] In addition, an element in the present invention is referred to as "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 illustrative purposes and do not represent the only implementation.

[0041] Please refer to Figures 1 to 12 , in an embodiment of the present invention, a kiln structure of a multi-point circulating combustion system includes a kiln 1. 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. Among them, 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 arranged on both sides of the lower part of the base body 11, and the exhaust ports 13 are connected to corresponding pipelines 2. An exhaust passage is provided in the lower part of the base body 11. The inner interface of the exhaust passage is connected to the inverted cone cavity structure, and the outer interface of the exhaust passage is connected to the corresponding exhaust port 13.

[0042] The exhaust passage includes a horizontal exhaust passage 15 and an inclined exhaust passage 16. An annular passage 17 is provided in the refractory castable at the outer interfaces of the horizontal exhaust passage 15 and the inclined exhaust passage 16, and the annular passage 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 passage 15, so as to realize real-time observation of the roasting situation of the raw materials in the kiln through the observation hole 118 and the horizontal exhaust passage 15. The inclined exhaust passage 16 has a channel structure with a lower inner part and a higher outer part, which can effectively prevent the raw materials from flowing out and can also make the heat fill the raw materials, so that the roasting is sufficient.

[0043] 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 their connection.

[0044] 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 one 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 base body 11 in a ring shape through the fuel inlet 18. The air inlets one 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 one 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 one 117 to achieve communication therebetween. The hot air exchanger 21 is of an overall cavity structure 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.

[0045] This embodiment is applied to a multi-point circulating combustion system, which includes a plurality of kilns 1. Adjacent kilns 1 are connected through a pipeline 2. A valve 9 is provided on the pipeline 2 between adjacent kilns 1 to realize the opening and closing of the corresponding pipeline 2.

[0046] A gas collecting box 3. Exhaust pipes 4 are provided between all the kilns 1 and the gas collecting box 3 to realize the individual 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 the pipeline 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.

[0047] The gas collecting box 3 is of an overall cylindrical structure. 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 connected to the bag filter 7.

[0048] There are at least two induced draft fans 22, which are symmetrically distributed on the outer side of the lower part of the air collecting box 3; the air inlets 31 are symmetrically distributed around the top of the air collecting box 3; a flow guiding column 25 is arranged in the middle of the air collecting box 3, and 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 air 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 air collecting box 3 and keep the air pressure at each air inlet 31 uniform and stable.

[0049] The multi-point circulating combustion system of the work card wire in this embodiment has the following advantages:

[0050] 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 and fast for maintenance;

[0051] 2. Obvious environmental protection and energy-saving effects: Because the waste heat of the tail gas is fully utilized before being discharged, the thermal utilization rate is high and the heat loss is small;

[0052] 3. Fewer workers and low labor cost: Under the same production capacity, compared with the tunnel kiln, the labor cost is saved by more than 60%;

[0053] 4. Low labor intensity and good working environment: The production process is greatly reduced, the manual operation links are basically eliminated, and the dusty working environment is fundamentally improved;

[0054] 5. Strong adaptability to raw materials: Since the bauxite used as the raw material is a non-renewable resource, the raw materials are becoming increasingly scarce. Especially the supply of high-grade bauxite is decreasing day by day and the price is rising. It overcomes the quality problems such as "collapse of the car body" when using high-iron bauxite in the tunnel kiln, resulting in the inability to burn through and cook thoroughly in the middle part. It can adapt to bauxite of different grades, which plays a significant role in both the adaptability to the raw material market and the reduction of production costs;

[0055] 6. The raw ore (raw material) directly enters the kiln through the belt conveyor (raw material conveyor belt). Each kiln body is connected to each other. During roasting, the tail gas passes through the connected kiln bodies filled with raw materials (raw materials) according to a certain process design and then is discharged. Thus, the waste heat of the tail gas is used to preheat the raw ore (raw material) in the connected kiln, greatly saving energy consumption, and thus achieving the purpose of energy conservation and consumption reduction;

[0056] 7. The dust removal system uses a bag filter, and the reverse blower is used for dust cleaning. The dust removal effect is good, and the dust removal powder is recycled and processed for reuse;

[0057] 8. The burned cooked ore directly enters the heat preservation equipment for heat preservation after passing through the discharge trolley, greatly reducing the heat loss and reducing the smelting energy consumption.

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

[0059] First, all the valves 9 in this embodiment are closed to isolate each kiln 1 independently. The corresponding air inlets 19, air inlet 117, observation holes 118, and discharge ports 14 on the kiln 1 are closed. Then, feeding starts. In this embodiment, a crushing system is used to crush the raw materials (i.e., bauxite) so that their sizes meet 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 raw materials to ensure that the weights of the raw materials in the two kilns 1 meet the production regulations.

[0060] After the raw material input is completed, the raw material feeding ports 115 on the kilns are closed respectively. At this time, the opening and closing valve 8 of the exhaust pipe 4 connected to the kiln C that needs to be roasted is closed, and the opening and closing valve 8 of the exhaust pipe 4 connected to the kiln D that needs to be preheated is opened. The valve 9 on the pipeline 2 between the kiln C and the kiln D is opened, and the induced draft fan 22 is started. The air inlet 117 of the kiln C is opened. Then, under the action of the induced draft fan 22, the air flow direction is: air inlet 117 of the kiln C - kiln C - pipeline 2 - kiln D - exhaust pipe 4 connected to the kiln D - gas collecting box 3 - bag filter 7. Natural gas is input into the kiln C through the gas input pipe 6, and the kiln C is ignited to start roasting the raw materials (bauxite). At this time, the valve 9 between the kiln C and the kiln D has been opened. Since the inlet 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. The nozzle of the jet port 20 is vertically downward, that is, the high-temperature air flow mixed with air and natural gas flows downward in a spiral shape into the raw materials (bauxite) in the kiln C to continuously roast the raw materials. 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, flows through all the raw materials in the kiln D, and then 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 materials in the kiln D, and the impurities containing useful solid or fog-like 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 circular shape in a tangential 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 fully roasted and evenly heated, and there will be no quality problems such as the middle part of the raw materials in the tunnel kiln not being burned through or cooked. And there are evenly arranged air extraction channels (horizontal air extraction channel 15 and inclined air extraction channel 16) at the bottom of the kiln C, and this air extraction channel is connected through the annular channel 17 and connected to the pipeline 2, realizing the same 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 fully and uniformly roasted.

[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 and achieve 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 through the discharge trolley for heat preservation, 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 realized 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 preheating the corresponding kilns are the same as the above-described process, and this application will not repeat them.

[0065] During the roasting of multiple kilns and the preheating of the kilns, since the pipe orifice direction of the air draft pipe 24 in the air collecting box 3 is the tangential direction of the structure of the air collecting box 3, the air draft pipe 24 and the guide column 25 cooperate to realize the spiral flow of the gas in the air collecting box 3 and keep the air pressure at each air inlet 31 uniform and stable; 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 kiln are in the same state and ensuring the roasting efficiency and quality of the roasted kiln 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 enterprise conditions 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 arrangement relationship with the air collecting fan 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, reducing 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 of 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 only for the purpose of describing specific embodiments, 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 kiln structure of a multi-point circulating combustion system, comprising a plurality of kilns (1), characterized in that: Adjacent kilns (1) are connected through pipelines (2), and a closed-loop structure is formed by connecting multiple kilns (1) through pipelines (2). 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 arranged 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 arranged in 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 arranged 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). A plurality of air inlet ports (19) are evenly arranged in the middle of the base body (11). A preheating air duct (112) is arranged between the base body (11) and the refractory bricks (110). A horizontal air inlet duct (113) is arranged 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 arranged between the air inlet port (19) and the preheating air duct (112) to achieve communication therebetween.

2. The kiln structure of a multi-point cyclic combustion system according to claim 1, characterized in that: An observation hole (118) is arranged on the outer side of the base body (11) at a position corresponding to the horizontal air extraction channel (15), so as to observe the roasting situation of the raw materials in the kiln in real time through the observation hole (118) and the horizontal air extraction channel (15).

3. The kiln structure of a multi-point cyclic combustion system according to claim 1, characterized in that: 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.

4. The kiln structure of a multi-point circulating combustion system according to claim 1, characterized in that: The kiln top cover structure (12) includes a raw material inlet port (115) arranged in the middle of the kiln top cover structure (12). An air extraction and exhaust port (116) is arranged on the kiln top cover structure (12) on one side of the raw material inlet port (115). The air extraction and exhaust port (116) is connected to the corresponding exhaust pipe (4). An air inlet port one (117) and a fuel inlet port (18) are respectively arranged on the kiln top cover structure (12). The fuel inlet port (18) is connected to the corresponding gas input pipe (6).

5. The kiln structure of a multi-point circulating combustion system according to claim 4, characterized in that: The air inlet direction of the fuel inlet port (18) is the tangential direction of the kiln top cover structure (12), so that the gas flows into the base body (11) in a ring shape through the fuel inlet port (18).

6. The kiln structure of a multi-point cyclic combustion system according to claim 4, characterized in that: The first air inlet (117) is symmetrically distributed around the top of the kiln top cover structure (12). The same number of jet nozzles (20) as that of the first air inlet (117) are arranged 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 arranged between the jet nozzles (20) and the corresponding first air inlet (117) to achieve communication therebetween.

7. The kiln structure of a multi-point circulating combustion system according to claim 6, characterized in that: The hot air exchanger (21) is of an overall cavity structure and is arranged inside the kiln top cover structure (12). A partition is arranged inside the cavity structure so that the hot air exchanger (21) forms a zigzag channel, enabling the air to be preheated when entering from the jet nozzles (20).

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