Calcining furnace and calcining system with same

Abstract

The invention provides a calcining furnace and a calcining system with the calcining furnace, the calcining furnace comprises a plurality of baffling calcining units, the plurality of baffling calcining units are sequentially connected, each baffling calcining unit comprises a shell and a baffle plate, the shell comprises an inlet, an outlet and a baffling channel communicated with the inlet and the outlet, and the baffle plate is arranged in the shell. The inlet and the outlet are staggered in the left-right direction of the shell; the baffle plate is arranged in the baffle channel and at least shields part of the inlet. The calcining furnace and the calcining system with the calcining furnace have higher calcining efficiency, better product quality and lower energy consumption and cost, and can flexibly meet the calcining requirements of materials of different types and specifications.

Description

Technical Field

[0001] The invention relates to the technical field of coal gangue calcining, and in particular to a calcining furnace and a calcining system having the same. Background Art

[0002] In the comprehensive utilization and processing of coal gangue, dynamic calcination technology realizes the rapid heating and deep conversion of materials such as coal gangue through rapid heat exchange and chemical reaction between high-temperature gas and powder materials. In related technologies, dynamic calcination technology is mainly divided into two categories: cyclone dynamic calcination and direct current dynamic calcination. These two calcination methods are only suitable for occasions with low calcination intensity. For products that require high-intensity calcination, large equipment such as smelting furnaces are still required. However, for coal gangue, due to its low energy density and high calcination intensity, the above two calcination technologies are difficult to ensure that the coal gangue reaches the ideal degree of chemical reaction and organizational structure changes during the calcination process, thereby affecting the quality and performance of the final product. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, an embodiment of the present invention provides a calcining furnace with higher calcining efficiency, better product quality, lower energy consumption and cost, and can flexibly adapt to the calcining requirements of materials of different types and specifications.

[0004] In addition, an embodiment of the present invention also provides a calcining system having the above calcining furnace.

[0005] The calcining furnace provided in an embodiment of the present invention includes a plurality of baffle calcining units, which are connected in sequence, and the baffle calcining units include a shell and a baffle plate, the shell includes an inlet, an outlet and a baffle channel connecting the inlet and the outlet, and the inlet and the outlet are staggered in the left and right directions of the shell; the baffle plate is arranged in the baffle channel, and the baffle plate at least blocks part of the inlet.

[0006] The calcining furnace provided in the embodiment of the present invention adopts a modular structure, and is composed of multiple baffle calcining units connected in sequence. Each unit is provided with a baffle channel and a baffle plate to guide the material to undergo multiple turns and collisions during the flow process, thereby promoting uniform heat transfer and sufficient reaction of the material. The calcining furnace of the present invention has higher calcination efficiency, better product quality, lower energy consumption and cost, and can flexibly adapt to the calcination needs of materials of different types and specifications. It is an important technological innovation in the field of material calcination.

[0007] In some embodiments, the baffle has a curved surface, the concave side of the curved surface is arranged toward the inlet, and the curved surface is arranged tangent to the side wall of the shell.

[0008] In some embodiments, the baffle channels of two adjacent baffle calcining units are connected, and the baffle channels in two adjacent baffle calcining units are arranged in an S shape.

[0009] In some embodiments, the shell includes a first side wall, a second side wall, a third side wall and a fourth side wall connected to each other, the first side wall and the third side wall are arranged opposite to each other, and the second side wall is inclined relative to the fourth side wall from the inlet toward the outlet.

[0010] In some embodiments, the angle between the second side wall and a horizontal plane where the inlet is located is 70° to 80°.

[0011] In some embodiments, the height of the baffled calcining unit is 1800 mm to 2000 mm.

[0012] In some embodiments, the shell is made of high temperature resistant and corrosion resistant material.

[0013] In some embodiments, the calculation formula of the calcination intensity of the calcined material by the calcination furnace is as follows:

[0014]

[0015] In the formula, C e is the calcination intensity; K is the calcination coefficient; L is the height of the calcination furnace; N s L is the number of times the material is baffled in the baffle calcining unit; e is the number of baffled calcining units; d s is the particle size of the material; s is the material density; ρ is the fluid medium density of the material; C is the friction resistance coefficient; D is the inner diameter of the calcining furnace.

[0016] In addition, the calcining system provided in an embodiment of the present invention includes a feeding device, a flue gas circulation device and the calcining furnace described in the above embodiment, wherein the feeding device is used to transport materials to the inlet of the calcining furnace, and the flue gas circulation device is used to purify and treat the flue gas discharged from the calcining furnace.

[0017] In some embodiments, the flue gas circulation device includes a dust collector and a heat exchanger, wherein the dust collector is used to remove particulate matter in the flue gas, and the heat exchanger is used to heat the treated flue gas before transporting it to the calcining furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of a calcining furnace provided in one embodiment of the present invention.

[0019] Figure 2 It is a schematic diagram of the three-dimensional structure of a calcining furnace provided in one embodiment of the present invention.

[0020] Figure 3 It is a schematic diagram of the internal structure of a calcining furnace provided in one embodiment of the present invention.

[0021] Figure 4 It is a schematic diagram of the internal structure of the calcining furnace provided by one embodiment of the present invention at another angle.

[0022] Figure 5 It is a schematic structural diagram of a calcining system provided in one embodiment of the present invention.

[0023] Reference numerals:

[0024] 10. calcining furnace; 101. baffle calcining unit;

[0025] 11. Shell; 111. Inlet; 1111. Coarse material port; 1112. Fine material port; 1113. Air supply port; 112. Outlet; 113. Baffle channel; 114. First side wall; 115. Second side wall; 116. Third side wall; 117. Fourth side wall;

[0026] 12. baffle; 121. cambered surface; 122. concave side;

[0027] 20. Feeding device;

[0028] 30. Flue gas circulation device; 31. Dust collector; 32. Heat exchanger;

[0029] 41. Cyclone; 42. Waste heat utilization boiler; 43. Chimney; 44. Suspension cooling device; 45. Desulfurization spray tower; 46. Gas storage tank. DETAILED DESCRIPTION

[0030] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0031] like Figures 1 to 4 As shown, an embodiment of the present invention provides a calcining furnace 10, which includes a plurality of baffle calcining units 101, which are connected in sequence, and the baffle calcining units 101 include a shell 11 and a baffle plate 12, the shell 11 includes an inlet 111, an outlet 112, and a baffle channel 113 connecting the inlet 111 and the outlet 112, the inlet 111 and the outlet 112 are staggered in the left and right directions of the shell 11, the baffle plate 12 is arranged in the baffle channel 113, and the baffle plate 12 at least blocks part of the inlet 111, so that the material entering through the inlet 111 at least partially hits the baffle plate 12. Among them, Figure 3 The arrow in the middle shows the flow path of the material in the baffle channel 113.

[0032] Specifically, in the calcining furnace 10, a plurality of baffle calcining units 101 can be connected in series to form a continuous and efficient calcining system. That is, the inlet 111 of one of two adjacent baffle calcining units 101 is connected to the outlet 112 of the other, and the number of baffle calcining units 101 can be flexibly adjusted according to actual needs, and maintenance and upgrading are convenient.

[0033] Furthermore, the inlet 111 and outlet 112 of the same baffle calcining unit 101 are staggered in the left and right directions, thereby forming a more tortuous baffle channel 113, ensuring that the material can undergo multiple turns and expansions during the flow process, achieving more uniform heat transfer and deeper calcination effect, which helps to improve the calcination efficiency.

[0034] Furthermore, the baffle channel 113 includes an acceleration channel between the inlet 111 and the baffle 12, and the acceleration channel is arranged along the height direction of the shell so that the material entering from the inlet can have a higher speed. Moreover, the baffle 12 blocks part of the inlet 111, so that the material entering from the inlet 111 can collide with the baffle 12 after passing through the acceleration channel, which not only changes the speed and flow direction of the material, but also promotes the mixing and crushing between the material particles, helps to increase the surface area of ​​the material, and improves the heat exchange efficiency. At the same time, the kinetic energy generated by the collision can also help the material overcome the effect of gravity to a certain extent and maintain its continuous flow in the baffle channel 113.

[0035] In addition, during the calcination process of the material in the calcining furnace 10, the material can be gradually advanced through the continuously arranged baffle calcining units 101, and each time it passes through a unit, it will experience one or more baffle and impact processes. This continuous baffle and impact not only enables the material to achieve sufficient heat exchange and uniform heating in the calcining furnace 10, but also promotes the full progress of the chemical reaction inside the material. Finally, after reaching the predetermined calcination temperature and time, the material is discharged from the outlet 112 of the last unit to become a high-quality calcined product.

[0036] In summary, the calcining furnace 10 provided in the embodiment of the present invention adopts a modular structure, and is composed of multiple baffle calcining units 101 connected in sequence. Each unit is provided with a baffle channel 113 and a baffle plate 12 to guide the material to undergo multiple turns and collisions during the flow process, thereby promoting uniform heat transfer and sufficient reaction of the material. The calcining furnace 10 of the present invention has higher calcination efficiency, better product quality, lower energy consumption and cost, and can flexibly adapt to the calcination needs of materials of different types and specifications. It is an important technological innovation in the field of material calcination.

[0037] In this embodiment, the baffle 12 has a curved surface 121, and the inner concave side 122 of the curved surface 121 is arranged toward the inlet 111, and the curved surface 121 is arranged tangent to the side wall of the shell 11. The inner concave side 122 of the curved surface 121 is arranged toward the inlet 111 of the calcining furnace 10, so that part of the material entering from the inlet 111 will directly hit the curved surface 121 of the baffle 12, which not only helps to break up the material agglomerates and promote the uniform distribution of material particles, but also lays a foundation for subsequent multiple turns and collisions.

[0038] Moreover, the arc surface 121 is tangent to the side wall of the shell 11, and can form a relatively smooth guide track in the calcining furnace 10, providing a stable path for the flow of materials, which not only ensures the directionality and stability of the materials during high-speed flow, effectively avoids material splashing or accumulation caused by sudden changes in flow direction, but also significantly reduces the energy dissipation caused by changes in flow state.

[0039] At the same time, since unnecessary material collision and friction are reduced, the baffle 12 can also extend the service life of the internal components of the calcining furnace 10 and reduce maintenance costs. In the embodiment of the present invention, the radius of the arc surface 121 is R, and R is set to 1333 mm.

[0040] In some embodiments, the baffle channels 113 of two adjacent baffle calcining units 101 are interconnected, and the baffle channels 113 in two adjacent baffle calcining units 101 are arranged in an S shape, which can not only increase the flow path length of the material during the calcination process, so that the material can be more fully in contact with the high-temperature gas and heat exchange occurs, but also further promote the mixing and crushing between material particles through multiple turns and collisions, thereby improving the heat conduction efficiency and calcination uniformity.

[0041] In addition, the S-shaped continuous baffle channel also has a certain buffering effect, which can slow down the flow rate of the material and make the material stay in the calcination area for a longer time, thereby ensuring that the material achieves an ideal calcination effect.

[0042] In some embodiments, the shell 11 includes a first side wall 114, a second side wall 115, a third side wall 116 and a fourth side wall 117 that are connected to each other. The first side wall 114 and the third side wall 116 are arranged opposite to each other, and the second side wall 115 is inclined relative to the fourth side wall 117 from the inlet 111 toward the outlet 112, which can guide the material entering from the inlet 111 to flow toward the outlet 112 along a predetermined path.

[0043] Among them, when the material is put into the calcining furnace 10, its initial flow direction may appear chaotic due to various factors, but as the material gradually goes deeper into the calcining area, the inclination angles of the second side wall 115 and the fourth side wall 117 can guide the material in the correct direction, ensuring the continuity and smoothness of the material during the calcining process.

[0044] Furthermore, the angle between the second side wall 115 and the horizontal plane where the inlet 111 is located is 70° to 80°, so that the guiding effect and flow resistance of the material can be effectively balanced. If the angle is too small, although the guiding property of the material can be enhanced, the friction and energy loss of the material during the flow process may be increased, resulting in a decrease in calcination efficiency; while if the angle is too large, the guiding effect on the material may be weakened, making the material flow too slow, which is not conducive to the full mixing and heat exchange of the material in the calcination area.

[0045] Therefore, the angle of 70° to 80° in this embodiment can not only ensure that the material flows smoothly and stably toward the outlet 112 when guided by the second side wall 115, but also slow down the flow speed of the material to a certain extent, so that the material stays in the calcination area for a longer time, thereby more fully absorbing heat and reacting chemically with the surrounding medium, which can not only improve the overall efficiency of the calcination process, but also help to improve the uniformity and quality stability of the product.

[0046] like Figure 3 As shown, in this embodiment, the angle between the second side wall 115 and the horizontal plane where the inlet 111 is located is α, and α is set to 71.6°, thereby ensuring that the material can flow smoothly from the inlet 111 to the outlet 112 while also taking into account the residence time and heat exchange efficiency of the material in the calcination area.

[0047] Furthermore, the height of the baffle calcining unit 101 is 1800mm to 2000mm. Among them, the appropriate height can ensure that the material has enough space in the baffle calcining unit 101 for sufficient mixing and crushing, thereby promoting the uniform transfer of heat and the in-depth chemical reaction. Too low a unit height may limit the flow and mixing of materials, resulting in poor calcination effect; while too high a unit height may increase the energy loss of materials during the flow process, and even cause the problem of unstable flow. In this embodiment, the height of the baffle calcining unit 101 is A, where A is 2000mm.

[0048] In this embodiment, the longest path of the material flowing in the baffle calcining unit 101 in the up-down direction is B, which can be set to 1805 mm, ensuring that the material has enough time and space to be fully mixed, crushed and heat exchanged in the baffle calcining unit 101. In the process of flowing along this path, the material can be gradually heated, evenly heated, and fully chemically react with the surrounding high-temperature gas and medium, thereby achieving an ideal calcining effect.

[0049] Furthermore, the maximum spacing between the second side wall 115 and the fourth side wall 117 is C, and C is set to 1320 mm, which provides sufficient lateral space for the material in the baffle calcining unit 101, thereby helping the material to maintain a certain degree of dispersion during the flow process, reducing the accumulation and blockage between the materials, and ensuring that the material can smoothly move along the baffle channel 113. At the same time, sufficient lateral space also provides conditions for the material to fully contact with the high-temperature gas, promoting the effective transfer of heat and the in-depth chemical reaction.

[0050] In this embodiment, the housing 11 is made of a high temperature resistant and corrosion resistant material to ensure that the housing 11 maintains a stable structural strength and shape at high temperatures, thereby avoiding equipment failure or safety accidents caused by softening or melting of the material. In addition, the housing 11 can be effectively protected from erosion by corrosive gases or liquids that may be generated during the calcination process, thereby extending the service life of the equipment.

[0051] In this embodiment, the calculation formula of the calcination intensity of the calcined material by the calcination furnace 10 is as follows:

[0052]

[0053] In the formula, C e is the calcination intensity; K is the calcination coefficient; L is the height of the calcination furnace; N s L is the number of times the material is baffled in the baffle calcining unit; e is the number of baffled calcining units; d s is the particle size of the material; s is the material density; ρ is the fluid medium density of the material; C is the friction resistance coefficient; D is the inner diameter of the calcining furnace.

[0054] It should be noted that the calcination intensity can be understood as the degree of calcination of the material in the calcination furnace 10, which can be regarded as the amount of loss on ignition in the field of decarburization. That is to say, the greater the calcination intensity, the more thorough the calcination of the material and the lower the loss on ignition.

[0055] The calcination intensity is related to the calcination time, the number of calcinations and the calcination sequence. The calcination time refers to the residence time in the calcination furnace 10, which is affected by the suspension speed of the material in the calcination furnace 10. The relationship between the suspension speed of the material in the calcination furnace 10 and the particle size of the material can be expressed by the following formula:

[0056]

[0057] Where V0 is the suspension velocity; D is the inner diameter of the calcining furnace; d s is the particle size of the material; s is the material density; ρ is the fluid medium density of the material; C is the friction resistance coefficient.

[0058] It can be seen from the above formula that the suspension speed of the material is proportional to the particle size of the material, that is, in a baffle calcining unit 101 of the calcining furnace 10, under the action of the wind speed V0, the material particle size is d s The particles are suspended and packed, and those smaller than d s The particles larger than d will flow toward the outlet 112 and enter the next baffle calcining unit 101 or hit the baffle plate 12; s The particles will sink back to the outlet 112. That is to say, during the calcination process, the particle size of the material will gradually decrease and pass through each baffle calcination channel in turn until the particle size of the material meets the particle size requirement of the last baffle calcination unit 101, and then it will be discharged from the outlet 112 of the last baffle calcination unit 101.

[0059] The calcination times refer to the number of times the material is baffled in the calcining furnace 10, including the baffles of the material particles rising and falling in a baffle calcining unit 101, and also the baffles of large particles realized by the baffles 12. In order to avoid excessive accumulation of material in the calcining furnace 10, in each baffle calcining unit 101, the suspension velocity V of the material with most particle sizes is S It should be greater than V0 and in an upward state. According to the commonly used standards for particle size distribution, the particle size below D10 can be regarded as no deflection, the number of deflections N is regarded as 0, and the particle size D50 is regarded as the number of deflections N required for the material to reach the calcination strength. s , D90 is regarded as a non-combustible component in the calcination process, that is, the particle size does not decrease with the increase of calcination intensity, and it is always unable to enter the laminar state. Its baffle number is close to the limit value, and during the calcination process, particles of different particle sizes have different Reynolds numbers. Some particles will follow the rising air to form laminar flow. Therefore, adding a baffle 12 to the unit structure can realize the forced baffle of most particles and realize the overall upward movement of the material without blocking or accumulating materials. At the same time, ensure that materials above D10 particle size participate in the baffle calcination to balance the calcination intensity and processing volume. The expression formula of the Reynolds number is:

[0060] Re=ρvL / μ;

[0061] Wherein, ρ is the fluid medium density of the material; μ is the dynamic viscosity coefficient; v is the characteristic velocity of the flow field (average flow velocity); L is the characteristic length of the flow field (particle size of the material).

[0062] Among them, the Reynolds number physically represents the ratio of the magnitude of the inertial force to the viscous force. The smaller the Reynolds number, the more significant the influence of the viscous force, and the larger the Reynolds number, the more significant the influence of the inertia. For the calcining furnace provided by the present invention, the two adjacent baffle calcining units are connected, and the outlet 112 of the baffle channel 113 faces the baffle plate 12 of the next unit, so that the material undergoes multiple baffles and mixing during the upward flow. Changes in the particle size of the material will affect its suspension stability and heat transfer efficiency in the airflow. The flow of the material in the calcining furnace can be approximated as pipeline flow. When the Reynolds number is less than 2300, the flow can be laminar, and when the Reynolds number is 2300 to 4000, it is transitional, and combined with the volume formula of the sphere, it can be obtained:

[0063]

[0064] Wherein, D0 is the critical velocity of the baffle in the calcining furnace 10; ρ is the fluid medium density of the material; and μ is the dynamic viscosity coefficient.

[0065] In addition, the inclination angle of the baffle 12 may also affect the number of baffles. Figure 3 As shown, the larger the angle β between the baffle plate 12 and the horizontal line of the outlet 112, the fewer the number of baffles. Therefore, it can be adjusted according to product needs, but there is a maximum inclination angle β max , so that the number of deflections is reduced to one; when the angle β is greater than the maximum inclination angle β max When the baffle plate 12 is set, the setting of the baffle plate 12 becomes meaningless, so the angle should be set lower than this value. It should be noted that the maximum inclination angle β of the baffle plate 12 is max It can be determined according to the properties of the material, the air supply volume, etc. In this embodiment, the maximum inclination angle β of the baffle 12 is max Can be set from 45° to 60°.

[0066] The calcination sequence refers to the order in which materials enter and leave the calcination furnace 10, that is, first-in-first-out or last-in-last-out. In the calcination furnace 10 provided by the present invention, there is no accumulation of materials in the furnace, the calcination efficiency is high, the fine materials reach the calcination strength in a few seconds at the fastest, and the coarse materials are suspended and returned in the furnace, and only stay for tens of seconds.

[0067] Among them, in the original calcining furnace, the materials added first will be deposited at the bottom, and the materials added later will be at the top. When discharging, the upper materials will be discharged first, and the bottom materials cannot be discharged completely, or it is necessary to stop feeding first, clean up and then feed new materials. In the calcining furnace 10 provided by the present invention, feeding and discharging are continuous processes, and first-in-first-out, coarse materials and fine materials do not affect each other, and the discharge is continuous and uniform. The calcination order in the calcining furnace provided by the present invention is completely consistent with the order in which the materials enter from the bottom, rise step by step, and leave from the top, so the unit stage number of the calcining furnace 10 is used as the value of the calcination order.

[0068] During use of the calcining furnace 10 provided by the present invention, a fine material port 1112 , a coarse material port 1111 and an air supply port 1113 are provided at the inlet 111 of the first-stage baffle calcining unit 101 of the calcining furnace 10 , wherein the fine material port 1112 is relatively located above the coarse material port 1111 . Taking the clean utilization of coal gangue project of China Coal Technology and Engineering Ecological Environment Technology Co., Ltd. as an example, in this project, the coal gangue powder is preheated to 300°C. Because suspension preheating is adopted in the preheating process, it is separated into two streams of fine powder and coarse powder through the cyclone 41, and enters the bottom of the calciner 10 through the fine material port 1112 and the coarse material port 1111 respectively. After the hot air exchanges heat with the flue gas after combustion, it reaches 700°C. The hot air enters the calciner 10, and the hot air moves upward, carrying the material upward. The fine powder has low weight, and moves upward along the inclined surface of the third side wall 116 with the hot air to enter the next level. The coarser coal gangue powder cannot "turn" in time, hits the baffle 12, falls along the curved surface 121 of the baffle 12, and is driven by the upward hot air to hit the baffle 12 again to realize the baffle movement. Among them, during the calcination process, the particle size of the coarse material gradually decreases, and the number of deflections is reduced accordingly, and the coarse material is discharged from the top of the calcining furnace 10, so that the different residence time of the coarse material and the fine material in the furnace can be utilized, and the automatic classification of the coal gangue powder in the calcining furnace 10 is successfully realized; and by adding or subtracting the number of deflection calcining units 101, the problems of over-burning of fine materials, low activity, under-burning of coarse materials, and incomplete burning can be effectively solved.

[0069] In addition, if Figure 5 As shown, a calcination system is also provided in one embodiment of the present invention, which includes a feeding device 20, a flue gas circulation device 30 and the calcination furnace 10 of the above embodiment. The flue gas circulation device 30 is used to purify and treat the flue gas discharged from the calcination furnace 10, thereby forming an efficient, environmentally friendly and sustainable calcination ecosystem.

[0070] Furthermore, the flue gas circulation device 30 includes a dust collector 31 and a heat exchanger 32. The dust collector 31 is used to remove particulate matter in the flue gas, and the heat exchanger 32 is used to transfer the treated flue gas to the calcining furnace 10 after heat exchange, together forming an efficient and environmentally friendly flue gas treatment and heat recovery system. This design not only effectively reduces the negative impact of the calcination process on the environment, but also achieves energy conservation and efficient utilization through heat recovery, making an important contribution to the sustainable development of the calcination industry.

[0071] Furthermore, the calcining system also includes a cyclone 41 , a waste heat utilization boiler 42 , a chimney 43 , a suspension cooling device 44 , a desulfurization spray tower 45 and a coal gas storage tank 46 . During the use of the calcining system, the gangue raw material is lifted by the elevator to the top of the suspended preheating device, passes through the cyclone 41, exchanges heat with the circulating coal gas or air, and is heated to 600°C (when the circulating gas is coal gas) or 300°C (when the circulating gas is air). The material flows downward and enters the inlet 111 of the calcining furnace 10. After high-temperature calcination and decarbonization at 850°C, it is discharged from the top outlet 112 of the calcining furnace 10 and enters the cyclone 41. The finished product flows out from the bottom of the cyclone 41, passes through the suspended cooling device 44, cools down and recovers the remaining heat to heat the circulating gas. The flue gas discharged from the top of the cyclone 41 exchanges heat with the air required for combustion in the calcining furnace 10 through the flue gas heat exchanger 32 to obtain 600°C inlet air. This realizes the entry of hot air and hot materials into the furnace, and the temperature of both comes from the calcined materials, which greatly reduces the energy consumption required for calcination. The flue gas after heat exchange passes through the tail dust remover 31 to separate the fine dust carried in the flue gas and is discharged through the chimney 43. If the heat required for flue gas heat exchange is excessive, the boiler 42 is used to adjust the load through the waste heat.

[0072] When coal gas is used as the circulating gas, the preheating temperature reaches 600°C, most of the volatile components in the coal gangue are extracted, purified and dust-removed through the desulfurization spray tower 45, and returned to the furnace for supplementary combustion as calcination fuel. The excess circulating coal gas is stored in a gas storage tank, and the amount of supplementary combustion can also be adjusted through the gas tank to make the temperature control of the multi-stage calcining furnace 10 more stable.

[0073] It should be noted that the calcining furnace 10 provided in the above embodiment can be applied to the calcining system. Therefore, the beneficial effects that can be achieved by the calcining system can refer to the beneficial effects corresponding to the calcining furnace 10 provided above, which will not be repeated here.

[0074] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0075] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0076] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0077] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0078] In the present invention, the terms "one embodiment", "some embodiments", etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0079] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A calcining furnace, characterized in that: It comprises a plurality of baffle calcining units, which are connected in sequence, and the baffle calcining units comprise: A shell, the shell comprising an inlet, an outlet and a baffle channel connecting the inlet and the outlet, the inlet and the outlet being staggered in a left-right direction of the shell; A baffle is disposed in the baffle channel, and the baffle at least blocks a portion of the inlet.

2. The calcining furnace according to claim 1, characterized in that: The baffle has a curved surface, the concave side of the curved surface is arranged toward the inlet, and the curved surface is arranged tangent to the side wall of the shell.

3. The calcining furnace according to claim 1, characterized in that: The baffle channels of two adjacent baffle calcining units are connected, and the baffle channels in two adjacent baffle calcining units are arranged in an S shape.

4. The calcining furnace according to claim 1, characterized in that: The shell includes a first side wall, a second side wall, a third side wall and a fourth side wall connected to each other. The first side wall and the third side wall are arranged opposite to each other, and the second side wall is arranged inclined relative to the fourth side wall from the inlet toward the outlet.

5. The calcining furnace according to claim 4, characterized in that: The included angle between the second side wall and the horizontal plane where the inlet is located is 70° to 80°.

6. The calcining furnace according to claim 1, characterized in that: The height of the baffled calcining unit is 1800 mm to 2000 mm.

7. The calcining furnace according to claim 1, characterized in that: The shell is made of high temperature resistant and corrosion resistant material.

8. The calcining furnace according to claim 1, characterized in that: The calculation formula of the calcination intensity of the calcined material by the calcination furnace is as follows: In the formula, C e is the calcination intensity; K is the calcination coefficient; L is the height of the calcination furnace; N s is the number of times the material is baffled in the baffle calcining unit; Le is the number of baffle calcining units; d s is the particle size of the material; s is the material density; ρ is the fluid medium density of the material; C is the friction resistance coefficient; D is the inner diameter of the calcining furnace.

9. A calcining system, characterized in that: It comprises a feeding device, a flue gas circulation device and a calcining furnace as claimed in any one of claims 1 to 8, wherein the feeding device is used to transport materials to the inlet of the calcining furnace, and the flue gas circulation device is used to purify and treat the flue gas discharged from the calcining furnace.

10. The calcining system according to claim 9, characterized in that: The flue gas circulation device includes a dust collector and a heat exchanger. The dust collector is used to remove particulate matter in the flue gas, and the heat exchanger is used to transfer the treated flue gas to the calcining furnace after heat exchange.

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