Low-rank coal burner and pyrolyzing furnace

Abstract

The invention relates to the field of pyrolysis, and discloses a low-rank coal burner and a pyrolyzing furnace. The low-rank coal burner comprises a combustion-supporting pipe, a gas pipe and a uniform distributor, and the combustion-supporting pipe extends in the first direction and is used for introducing combustion-supporting gas; the gas pipe sleeves the periphery of the combustion-supporting pipe and is used for introducing raw gas, and the gas outlet end of the gas pipe exceeds the gas outlet end of the combustion-supporting pipe in the first direction to form a mixing space; the uniform distributor is located between the combustion-supporting pipe and the gas pipe, the uniform distributor is connected to the periphery of the gas outlet end of the combustion-supporting pipe, the uniform distributor comprises a plurality of redirection plates arranged at intervals in the circumferential direction of the combustion-supporting pipe, every two adjacent redirection plates define a flow dividing channel, each flow dividing channel comprises two air openings formed in the first direction, and at least part of the redirection plates intersect with the first direction; the redirection plate comprises a plurality of flow guide holes which penetrate through the redirection plate in the thickness direction of the redirection plate. The mixing uniformity of raw gas can be improved, the temperature stability in the furnace is improved, and the energy utilization rate is increased.

Description

Technical Field

[0001] This application belongs to the field of pyrolysis, and in particular relates to a low-rank coal burner and pyrolysis furnace. Background Technology

[0002] Low-rank coals (such as lignite and long-flame coal) are characterized by high volatile matter and low calorific value. Their pyrolysis process requires heating to 300-800℃ in an oxygen-deficient or inert atmosphere to break down coal molecules into semi-coke, tar, and coal gas. The burner's function is to provide heat for pyrolysis and simultaneously process the semi-coke and gaseous products generated during pyrolysis.

[0003] Currently, pyrolysis furnace burners generally face the problem of insufficient premixing, which easily leads to local high temperature concentration during combustion. This not only makes furnace temperature fluctuations difficult to control, but also aggravates equipment corrosion and wear, shortens service life, and reduces energy utilization, becoming a bottleneck for the large-scale application of low-rank coal pyrolysis technology. Summary of the Invention

[0004] This application provides a low-rank coal burner and pyrolysis furnace, which can improve the mixing uniformity of raw coal gas, improve the temperature stability inside the furnace, and improve energy utilization.

[0005] On one hand, this application provides a low-rank coal burner, including a combustion-supporting pipe, a gas pipe, and a distributor. The combustion-supporting pipe extends along a first direction for introducing combustion-supporting gas. The gas pipe is sleeved on the outer periphery of the combustion-supporting pipe for introducing raw coal gas. Along the first direction, the gas outlet of the gas pipe extends beyond the gas outlet of the combustion-supporting pipe to form a mixing space. The distributor is located between the combustion-supporting pipe and the gas pipe and is connected to the outer periphery of the gas outlet of the combustion-supporting pipe. The distributor includes a plurality of deflector plates spaced apart circumferentially along the combustion-supporting pipe. Two adjacent deflector plates define a diversion channel. The diversion channel includes two air inlets arranged along the first direction. At least a portion of the deflector plates intersects the first direction. The deflector plates include a plurality of guide holes penetrating along their own thickness direction.

[0006] In some alternative embodiments, multiple redirection plates extend in parallel.

[0007] In some alternative embodiments, the redirecting plate includes a first bend and a second bend that are alternately arranged along a first direction. The first bend and the second bend have opposite bending directions along their own thickness direction, and both the first bend and the second bend have flow guide holes.

[0008] In some alternative embodiments, in a plane perpendicular to the first direction, the first bend of one of two adjacent deflectors overlaps with the second bend of the other deflector.

[0009] In some alternative embodiments, the redirection plate extends in a curved shape.

[0010] In some alternative embodiments, the redirecting plate includes a body portion and a cavity formed by the body portion. The body portion has openings at both ends along the length direction of the redirecting plate, and guide holes are opened on both side walls of the body portion along the circumferential direction. Both the openings and the guide holes are in communication with the cavity.

[0011] In some alternative embodiments, the plurality of guide holes include a first hole and a second hole, which are respectively opened on the two side walls of the body portion along the circumferential direction, and the first hole and the second hole are staggered.

[0012] In some alternative embodiments, the radial height of the redirecting plate along the gas pipe is H1, the combustion-supporting pipe is coaxial with the gas pipe and the distance between them is H2, and 0.65≤H1 / H2≤1.

[0013] In some alternative embodiments, the length of the distributor along the first direction is L1, the length of the mixing space along the first direction is L2, and 1≤L1 / L2≤2.5.

[0014] On the other hand, some embodiments of this application also provide a pyrolysis furnace, including the low-rank coal burner described above.

[0015] The low-rank coal burner and pyrolysis furnace of this application embodiment have a distributor installed between the combustion-supporting pipe and the gas pipe. Multiple redirecting plates arranged circumferentially define the diversion channel to achieve gas diversion. At least a portion of the redirecting plates of the distributor intersects with the first direction, forcing the airflow direction to change, generating a lateral velocity component, enhancing turbulence, and forming a complex flow field through the guide holes, while reducing resistance and improving the premixing effect of the raw coal gas. It also improves the circumferential uniformity of the raw coal gas. The diversion channel is connected to the mixing space to better mix with the combustion-supporting gas in the mixing space, so that the raw coal gas is burned uniformly, improving the service life of the equipment, and also enabling effective control of the furnace temperature of the pyrolysis furnace. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a low-rank coal burner according to some embodiments of this application; Figure 2 Show Figure 1 A magnified view of a portion of region A in the middle; Figure 3 Show Figure 2 Schematic diagram of the uniform distributor; Figure 4 Show Figure 3 A schematic diagram of the flattened state of part of the redirection plate; Figure 5 Show Figure 2 A schematic diagram of one end face structure of the medium structure.

[0018] Explanation of reference numerals in the attached figures: 100, Combustion aid pipe; 110, Mixing space; 200, Gas pipe; 300, Distributor; 310, Diverter plate; 311, Flow guide hole; 312, First bend; 313, Second bend; 320, Diversion channel; 321, Air outlet; 301, Main body; 302, Cavity; 303, Opening; X, First direction; Y, Thickness direction. Detailed Implementation

[0019] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0021] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0022] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0024] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0025] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0026] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0027] Low-rank coal is an important energy resource in the energy structure, but its high moisture and volatile matter content necessitate its conversion into raw coal gas through a pyrolysis furnace before utilization. As the core component of the pyrolysis furnace, the premixing effect of the raw coal gas and combustion-supporting gas directly determines the pyrolysis efficiency and equipment lifespan. Currently, pyrolysis furnace burners generally face the problem of insufficient premixing, which easily leads to localized high-temperature concentrations during combustion. This not only causes uncontrollable furnace temperature fluctuations but also exacerbates equipment corrosion and wear, shortens service life, and reduces energy utilization, becoming a bottleneck for the large-scale application of low-rank coal pyrolysis technology.

[0028] Specifically, the raw coal pyrolysis burner achieves energy conversion through the synergistic effect of pyrolysis and combustion, with the core component being the temperature control of the pyrolysis burner. The pyrolysis furnace, from top to bottom, consists of a drying layer (200-300℃), a dry distillation layer (oxygen-deficient pyrolysis to generate combustible gases and residues), and a reduction layer (CO). and H O is reduced by C to CO and H. The oxidation layer (750-800℃ high-temperature combustion for heating) is used. The carbon particles, tar, and raw coal gas produced during pyrolysis are then re-oxidized and released heat, achieving smokeless, odorless, and S2O-free emissions. Stable combustion by the burner ensures the bed temperature, allowing the carbonization furnace to operate stably and guaranteeing efficient purification and heat utilization. Existing burners suffer from unstable combustion, leading to uneven bed temperature and substandard products.

[0029] Existing low-rank coal burners mostly adopt a simple assembly structure of single-pipe combustion aid combined with external pipe gas delivery, lacking targeted airflow control design, which has several problems. For example, problem one is that raw coal gas is prone to local accumulation in the annular channel, with uneven circumferential distribution, which poses a hidden danger for premixing; problem two is that the airflow flows in a straight line along the axial direction, mainly laminar flow, with insufficient turbulence intensity, and the two gases only rely on natural diffusion to mix, resulting in long mixing time and poor mixing effect; problem three is that although some flow-blocking components can enhance turbulence, they are prone to forming airflow "dead zones", which leads to increased flow resistance and may also cause carbon buildup and blockage.

[0030] In view of this, embodiments of this application provide a low-rank coal burner. An auxiliary combustion pipe is fitted over the gas pipe, with the outlet extending beyond it, forming an independent mixing space and extending the mixing time. A circumferential redirecting plate of the distributor divides the raw coal gas into multiple uniform airflows, solving the problem of uneven distribution. The intersection of the redirecting plate with the first direction generates a lateral velocity component, enhancing turbulence, and the through-holes form bypass airflow, increasing the complexity of the flow field while reducing resistance. This design achieves uniform combustion of raw coal gas, extends equipment life, and precisely controls the pyrolysis furnace temperature, providing support for the efficient utilization of low-rank coal.

[0031] like Figures 1 to 3 As shown, some embodiments of this application provide a low-rank coal burner, including a combustion-supporting pipe 100, a gas pipe 200, and a distributor 300. The combustion-supporting pipe 100 extends along a first direction X for introducing combustion-supporting gas; the gas pipe 200 is sleeved around the outer periphery of the combustion-supporting pipe 100 for introducing raw coal gas. Along the first direction X, the gas outlet end of the gas pipe 200 extends beyond the gas outlet end of the combustion-supporting pipe 100 to form a mixing space 110; the distributor 300 is located between the combustion-supporting pipe 100 and the gas pipe. Between 200, the distributor 300 is connected to the outer periphery of the outlet end of the combustion-supporting pipe 100. The distributor 300 includes a plurality of deflector plates 310 arranged at intervals along the circumference of the combustion-supporting pipe 100. Two adjacent deflector plates 310 define a diversion channel 320. The diversion channel 320 includes two air outlets 321 arranged along the first direction X. At least a portion of the deflector plate 310 intersects with the first direction X. The deflector plate 310 includes a plurality of guide holes 311 that are arranged through it along its own thickness direction Y.

[0032] Exemplarily, the first direction X can be the axial direction of the burner or the axial direction of the combustion-supporting tube 100. In some examples, the material of the combustion-supporting tube 100 can be heat-resistant stainless steel, high-temperature alloy, or ceramic matrix composite. As an example, high-temperature alloy materials can withstand higher temperature environments and have excellent mechanical strength. In some examples, the shape of the combustion-supporting tube 100 can be cylindrical, prismatic, or hexagonal. Exemplarily, a cylindrical combustion-supporting tube 100 has low airflow resistance and is easy to process and form.

[0033] For example, the combustion-supporting pipe 100 is used to introduce a combustion-supporting gas, which can be air, oxygen, or a mixture of oxygen and nitrogen, etc.

[0034] In some examples, the gas pipe 200 may be made of heat-resistant carbon steel, heat-resistant stainless steel, or nickel-based alloys. Exemplarily, the gas pipe 200 may be a cylindrical sleeve, a stepped sleeve, or a corrugated sleeve; as an example, a cylindrical sleeve has low processing cost and good airflow stability.

[0035] In some examples, the portion of the gas pipe 200 extending beyond the gas outlet of the combustion-supporting pipe 100 can be a straight section, a flared section, or a constricted section. For example, a flared section can increase the volume of the mixing space 110 to prolong the mixing time. Exemplarily, the gas pipe 200 and the combustion-supporting pipe 100 can be coaxially or eccentrically arranged. For example, a coaxial arrangement ensures a uniform width of the annular channel and symmetrical airflow distribution between them.

[0036] In some examples, the connection between the distributor 300 and the outer periphery of the combustion-supporting pipe 100 can be achieved through welding, bonding, bolting, snap-fitting, or integral molding. As an example, welding can be performed using methods such as argon arc welding or plasma welding, which offers high connection strength and good sealing performance, suitable for high-temperature and high-pressure conditions. Specifically, the inner peripheral wall of the distributor 300 and the outer peripheral wall of the combustion-supporting pipe 100 are fixedly connected by welding, with the weld seams arranged continuously along the circumference to ensure sealing performance.

[0037] For example, the material of the redirecting plate 310 can be heat-resistant stainless steel, high-temperature alloy, or ceramic material, etc. For example, the number of redirecting plates 310 can be 4, 6, 8, 12, etc. As an example, multiple redirecting plates 310 are arranged at equal intervals along the circumference.

[0038] The number of diversion channels 320 is the same as the number of redirection plates 310. Exemplarily, the shape of the diversion channels 320 can be rectangular, trapezoidal, or arc-shaped. In some examples, the diversion channel 320 includes two air vents 321 arranged along the first direction X, namely an inlet air vent 321 and an outlet air vent 321. In some examples, the shape of the air vents 321 can be circular, square, polygonal, or strip-shaped. The sizes of the two air vents 321 can be the same or different. Exemplarily, when the size of the inlet air vent 321 is larger than that of the outlet air vent 321, the airflow velocity can be increased; when the size of the outlet air vent 321 is larger than that of the inlet air vent 321, the airflow resistance can be reduced; when the sizes are the same, the airflow stability is good. The side closest to the mixing space 110 is the inlet air vent 321.

[0039] The deflector plate 310 may intersect the first direction X partially or completely. The angle of intersection between at least a portion of the deflector plate 310 and the first direction X may be 30°, 45°, 60°, or 90°. Exemplarily, the shape of the deflector plate 310 may be a flat plate, an arc-shaped plate, or a zigzag plate, etc. For example, an arc-shaped deflector plate 310 can guide airflow in a curved flow, resulting in a gentler disturbance effect.

[0040] For example, the shape of the guide hole 311 can be circular, square, rhomboid, or elliptical, etc. For example, a circular guide hole 311 is easy to process and allows for smooth airflow. In some examples, the guide holes 311 can be arranged in a uniform array, gradually changing along the length of the redirector plate 310 (or divided into sections along the width of the redirector plate 310, etc.). As an example, a uniform array arrangement makes the airflow distribution uniform.

[0041] In this embodiment, the distributor 300 is disposed between the combustion-supporting pipe 100 and the gas pipe 200. Multiple redirecting plates 310, spaced circumferentially, define multiple diversion channels 320, achieving circumferential diversion of the raw gas. This ensures the raw gas is evenly distributed circumferentially within the annular channels, preventing localized airflow concentration. At least a portion of the redirecting plate 310 intersects the first direction X, forcing a change in the direction of the raw gas flow passing through the redirecting plate 310, generating a lateral velocity component. This breaks the original laminar flow state along the first direction X, enhancing the turbulence intensity of the airflow. Simultaneously, multiple guide holes 311 penetrating the redirecting plate 310 allow some airflow to bypass the main airflow, interacting with it to form a complex flow field. This improves the airflow disturbance effect while avoiding excessive obstruction of the airflow by the redirecting plate 310, reducing overall airflow resistance, and thus improving the output of the raw gas and the combustion-supporting pipe 100. The premixing effect of the combustion-supporting gas is achieved by the two air inlets 321 arranged along the first direction X of the diversion channel 320, which allow the raw coal gas to smoothly enter the diversion channel 320 and flow out from the outlet end. This outlet is connected to the mixing space 110 formed by the gas outlet end of the gas pipe 200 extending beyond the gas outlet end of the combustion-supporting pipe 100. After flowing out of the diversion channel 320, the raw coal gas enters the mixing space 110 and fully mixes with the combustion-supporting gas sprayed from the combustion-supporting pipe 100 within the mixing space 110. Due to the diversion and disturbance treatment of the raw coal gas by the distributor 300, its circumferential distribution uniformity is significantly improved, resulting in a uniform flame distribution during combustion of the mixed combustible gas. This avoids local high temperatures or incomplete combustion, thereby reducing local corrosion and wear inside the burner and improving the service life of the equipment. At the same time, the heat distribution generated by uniform combustion is stable, which allows the furnace temperature inside the pyrolysis furnace to be effectively controlled, ensuring the stability of the pyrolysis process.

[0042] In one embodiment of this application, a plurality of redirection plates 310 extend in parallel.

[0043] In some examples, the parallel extension of the deflector plate 310 can be parallel extension along a straight line, parallel extension along a curve, or parallel extension along a broken line. As an example, when the deflector plate 310 extends parallel along a curve, the extension trajectory of the deflector plate 310 is a parallel curve, and the diversion channel 320 defined by the adjacent deflector plates 310 is an arc-shaped channel. The airflow flows in a curved manner in the channel, resulting in a gentler disturbance effect and less resistance.

[0044] For example, the tilting direction of multiple diversion plates 310 is the same, so that the airflow turning direction and angle in all diversion channels 320 are consistent, ensuring that the airflow state of each diversion channel 320 in the circumferential direction is uniform, and further improving the circumferential uniformity of raw coal gas.

[0045] In this embodiment, multiple redirecting plates 310 extend in parallel, ensuring that the intersection angle between each redirecting plate 310 and the first direction X remains consistent. The cross-sectional shape and size of the diversion channels 320 defined by adjacent redirecting plates 310 are uniformly distributed circumferentially, ensuring that the flow state of the raw coal gas in each diversion channel 320 remains consistent. This avoids the airflow in some diversion channels 320 being too fast or too slow due to inconsistent extension directions of the redirecting plates 310, further improving the circumferential uniformity of the raw coal gas distribution. The parallel-extending redirecting plates 310 make the flow path of the airflow in the diversion channels 320 regular, reducing eddy current losses in the channels and lowering the overall airflow resistance. At the same time, it ensures that each diversion channel 320 has the same turning effect on the airflow, resulting in a uniform lateral velocity component. This ensures that the mixing degree of the raw coal gas and the combustion-supporting gas is consistent at each circumferential position, resulting in more uniform combustion, further extending the service life of the equipment, and improving the accuracy of the pyrolysis furnace temperature control.

[0046] Specifically, please refer to Figure 4 In an optional embodiment of this application, the redirecting plate 310 includes a first bending portion 312 and a second bending portion 313 alternately arranged along a first direction X. The bending directions of the first bending portion 312 and the second bending portion 313 along their own thickness direction Y are opposite, and both the first bending portion 312 and the second bending portion 313 have a guide hole 311.

[0047] For example, the shape of the first bend 312 can be a V-shaped bend, an arc-shaped bend, or a U-shaped bend, etc. As an example, the V-shaped bend 312 is formed by two planar segments connected at a preset angle, which has a simple structure and a significant effect on airflow deflection. The included angle between the two planar segments can be set to 60°, 90°, or 120°, etc. As an example, the U-shaped bend 312 consists of two parallel segments and a connecting segment, forming a cavity 302 to accommodate airflow, which can further enhance the secondary disturbance of airflow.

[0048] The second bend 313 bends in the opposite direction to the first bend 312, and its shape is the same as the first bend 312, forming a concave-convex shape. The alternation of the first bend 312 and the second bend 313 along the first direction X can be an alternation of equal length or an alternation of unequal length, etc.

[0049] In this embodiment, the redirecting plate 310 is alternately arranged with a first bend 312 and a second bend 313 along the first direction X and with opposite bending directions. This causes the airflow to constantly change its flow direction as it passes through the redirecting plate 310, significantly enhancing the lateral disturbance of the airflow and making the effect of breaking the laminar flow state more significant. The opposite bending directions form a continuous wave-shaped airflow path, prolonging the flow time of the airflow on the redirecting plate 310 and increasing the opportunity for interaction between airflows. At the same time, both the first bend 312 and the second bend 313 are provided with guide holes 311, so that bypass airflow can be formed in different bending areas, which together with the main airflow to construct a complex flow field. This not only avoids the airflow deviation caused by a single bending direction, but also further improves the circumferential uniformity of the raw coal gas, laying the foundation for the full mixing with the combustion-supporting gas, thereby ensuring combustion uniformity and extending the service life of the equipment.

[0050] In some alternative embodiments of this application, in a plane perpendicular to the first direction X, the first bend 312 of one of two adjacent deflector plates 310 overlaps with the second bend 313 of the other deflector plate 310.

[0051] For example, the overlap can be complete or partial. As an example, the projected coverage of the first bend 312 is 1 / 3 to 2 / 3 of the projected coverage of the second bend 313. Partial overlap ensures the disturbance effect while avoiding excessive resistance due to overly narrow diversion channels 320. The degree of overlap can be controlled by adjusting the installation parameters of the redirector plates 310, such as adjusting the circumferential spacing between adjacent redirector plates 310, or adjusting the bending depth of the first bend 312 and the second bend 313.

[0052] In one example, the diameter of the guide hole 311 of the first bend 312 of the deflector plate 310 is D1mm, and the diameter of the guide hole 311 of the corresponding overlapping area of ​​the second bend 313 of the deflector plate 310 can be set to D2mm, where D2 is greater than D1. The difference in aperture creates a difference in airflow velocity, which further enhances the interaction of airflow.

[0053] In this embodiment, the first bend 312 and the second bend 313 of adjacent redirecting plates 310 in the plane perpendicular to the first direction X overlap, making the cross-sectional shape of the diversion channel 320 more complex. The flow path of the airflow in the channel is further extended and more tortuous, which greatly increases the contact area and interaction time between the airflow and the redirecting plate 310. The "interlocking" region formed by the overlapping structure forces the airflow to generate multi-directional turning and vortices. The turbulence intensity is improved compared with the non-overlapping structure, which significantly enhances the uniformity of the raw coal gas. At the same time, the overlapping arrangement in the limited annular space maximizes the use of the structural space. It can achieve a stronger disturbance effect without increasing the overall size of the burner, ensuring that the raw coal gas has a highly uniform distribution state before entering the mixing space 110. When mixed with the combustion-supporting gas, it can quickly achieve a uniform mixing effect, avoiding the problem of incomplete local combustion or high temperature concentration, and further improving the service life of the equipment and the temperature control accuracy of the pyrolysis furnace.

[0054] In one specific example, the deflector plate 310 extends in a curved shape.

[0055] For example, the curved extension can be an arc-shaped extension, a parabolic extension, or a sinusoidal extension, etc. As an example, the trajectory of the deflector plate 310 with the sinusoidal extension is a sinusoidal curve with periodic changes in curvature, which causes the airflow to change direction periodically in the channel, generating regular turbulent fluctuations and enhancing the mixing effect.

[0056] In some examples, the curve of the redirector plate 310 can be bent towards the combustion pipe 100, towards the gas pipe 200, or alternately towards both sides. As an example, when bending alternately towards both sides, the redirector plate 310 bends alternately towards both sides along its length, making the diversion channel 320 wavy, further enhancing airflow disturbance. The radius of curvature of the curved redirector plate 310 can be designed according to the airflow velocity and disturbance requirements. For example, a larger radius of curvature is used under high flow velocity conditions to reduce drag, while a smaller radius of curvature is used under low flow velocity conditions to enhance disturbance.

[0057] In this embodiment, the redirecting plate 310 extends in a curved shape, allowing the airflow to flow along a curved trajectory when passing through it. Compared to a straight redirecting plate 310, the curved redirecting plate 310 provides a more continuous and smoother redirection effect on the airflow, avoiding the airflow separation phenomenon that may occur with a straight redirecting plate 310 and reducing airflow resistance. The curved extension of the redirecting plate 310 makes the diversion channel 320 curved, generating centrifugal force within the channel, further enhancing the turbulence intensity of the airflow. At the same time, the curved channel extends the flow path of the airflow, increasing the interaction time between airflows and promoting uniform mixing of raw coal gas. The surface airflow distribution of the curved redirecting plate 310 is more uniform, reducing the situation of excessively high or low local airflow velocities, making the bypass airflow effect of the guide hole 311 more stable, further improving the complexity and uniformity of the flow field, thereby enhancing the premixing effect of raw coal gas and combustion-supporting gas, ensuring combustion uniformity, extending equipment service life, and improving the accuracy of pyrolysis furnace temperature control.

[0058] Furthermore, in some embodiments of this application, the redirecting plate 310 includes a body portion 301 and a cavity 302 formed by the body portion 301. The body portion 301 has openings 303 at both ends along the length direction of the redirecting plate 310, and guide holes 311 are formed on both side walls of the body portion 301 along the circumferential direction. Both the openings 303 and the guide holes 311 are in communication with the cavity 302.

[0059] For example, the body portion 301 may be in the shape of a hollow cylinder, a hollow prism, etc. For example, the openings 303 at both ends of the body portion 301 along the length direction of the redirecting plate 310 may be square openings 303, circular openings 303, or trapezoidal openings 303, etc. The cavity 302, the openings 303, and the guide hole 311 are interconnected.

[0060] In some examples, the guide holes 311 on both sides of the cavity 302 can be arranged symmetrically, asymmetrically, or staggeredly. A symmetrical arrangement makes the airflow output on both sides of the cavity 302 uniform, an asymmetrical arrangement can adjust the airflow on both sides in a targeted manner, and a staggered arrangement can avoid the airflow from the guide holes 311 on both sides directly colliding, thus enhancing the disturbance effect.

[0061] In this embodiment, the main body 301 of the redirecting plate 310 encloses a cavity 302, with openings 303 at both ends and guide holes 311 on the circumferential side walls. This allows the raw coal gas flow to not only flow through the outer surface of the redirecting plate 310 and form a bypass flow through the guide holes 311, but also enter the cavity 302 through the openings 303 at both ends of the redirecting plate 310 along its length, and then flow out through the guide holes 311 on the circumferential side walls, forming a multi-path airflow and further enriching the complexity of the flow field. The presence of the cavity 302 increases the flow rate of the gas. The open path reduces the obstruction of the airflow by the redirecting plate 310, lowering the overall airflow resistance. At the same time, the airflow entering the cavity 302 interacts with the external airflow, generating more eddies and secondary flows, enhancing the turbulence intensity. Both the openings 303 at both ends and the guide holes 311 are connected to the cavity 302, allowing the airflow to form a circulating flow inside and outside the cavity 302, further promoting the uniform mixing of raw coal gas, improving its circumferential distribution uniformity, thereby enhancing the premixing effect with the combustion-supporting gas, ensuring uniform combustion, extending the service life of the equipment, and stabilizing the furnace temperature of the pyrolysis furnace.

[0062] In addition, in some optional embodiments of this application, the plurality of guide holes 311 include a first hole and a second hole, the first hole and the second hole are respectively opened on the two side walls of the body portion 301 along the circumferential direction, and the first hole and the second hole are staggered.

[0063] The staggered arrangement is staggered along the height direction of the redirection plate 310. That is, the projections of the first hole and the second hole in the radial direction along the gas pipe 200 do not coincide, and there is a radial distance between them. For example, the staggered distance between the first hole and the second hole can be equal spacing, gradually varying spacing, or grouped staggering, etc. As an example, grouped staggering can achieve a differentiated mixing effect in different sections.

[0064] As an example, the shape and size of the first and second holes can be the same or different. When the shape is the same but the size is different, the flow ratio of the airflow on both sides can be adjusted. When the shape is different but the size is the same, the flow direction of the airflow on both sides can be adjusted. When both the shape and size are different, a more complex airflow distribution can be achieved.

[0065] In this embodiment, the first and second holes are respectively opened on the two side walls of the main body 301 in a staggered manner, so that the airflows flowing out of the guide holes 311 on the two side walls will not directly collide, avoiding the weakening of disturbance caused by mutual cancellation of airflows. At the same time, the staggered arrangement of the first and second holes makes the outflowing airflows form an interlaced distribution in space, further enhancing the turbulence intensity and flow field complexity of the airflow. The staggered arrangement of the guide holes 311 extends the mixing path of airflows with different paths, increases the interaction time between airflows, promotes the uniform distribution of raw coal gas in the circumferential, radial and axial directions, and improves the overall uniformity of raw coal gas. This structure can also avoid excessive local airflow concentration, reduce airflow resistance, ensure smooth airflow, further enhance the premixing effect of raw coal gas and combustion-supporting gas, make combustion more uniform and complete, extend the service life of equipment, and improve the stability and accuracy of pyrolysis furnace temperature control.

[0066] In some optional embodiments of this application, reference is made to Figure 5 The radial height of the redirecting plate 310 along the gas pipe 200 is H1. The combustion-supporting pipe 100 is coaxial with the gas pipe 200 and the distance between them is H2, 0.65≤H1 / H2≤1.

[0067] As an example, the gas pipe 200 is a pipe of equal diameter. When the combustion-supporting pipe 100 and the gas pipe 200 are coaxially arranged, their central axes coincide, and the width of the annular channel is uniform along the circumference. In order to ensure coaxiality, a positioning structure can be set between the combustion-supporting pipe 100 and the gas pipe 200.

[0068] In some examples, the ratio of H1 / H2 is between 0.65 and 1. Different ratios correspond to different structural adaptations. For example, when H1 / H2=0.65, the radial height of the redirecting plate 310 is small, the height of the diversion channel 320 is large, and the airflow resistance is small, which is suitable for high-flow-rate raw coal gas conditions. When H1 / H2=0.8, the ratio of the radial height of the redirecting plate 310 to the channel spacing is moderate, taking into account both diversion uniformity and airflow resistance. When H1 / H2=1, the radial height of the redirecting plate 310 is equal to the channel spacing, the outer peripheral wall of the redirecting plate 310 is in contact with or has a clearance fit with the inner peripheral wall of the gas pipe 200, the height of the diversion channel 320 is the smallest, the diversion effect is the most significant, which is suitable for conditions with low flow rate and high uniformity requirements.

[0069] In this embodiment, the coaxial arrangement of the combustion-supporting pipe 100 and the gas pipe 200 ensures that the width of the annular channel between them is uniform along the circumference, providing symmetrical installation space for the flow distribution device 300. This ensures that the flow distribution channels 320 defined by multiple redirecting plates 310 have consistent circumferential dimensions, thereby ensuring the uniformity of the blast furnace gas flow in the circumference. The radial height H1 of the redirecting plate 310 and the distance H2 between the combustion-supporting pipe 100 and the gas pipe 200 satisfy 0.65≤H1 / H2≤1. This ratio range allows the redirecting plate 310 to make full use of the space of the annular channel, ensuring that the flow distribution channel 320 has sufficient flow area to reduce airflow resistance, and ensuring that the redirecting plate 310 has sufficient steering and disturbance effect on the airflow, avoiding the problem of poor flow distribution effect due to H1 being too small or excessive resistance due to H1 being too large.

[0070] In another optional embodiment of this application, the length of the distributor 300 along the first direction X is L1, the length of the mixing space 110 along the first direction X is L2, and 1≤L1 / L2≤2.5.

[0071] For example, the length L1 of the distributor 300 along the first direction X refers to the maximum length of the distributor 300 along the first direction X.

[0072] For example, the length L2 of the mixing space 110 along the first direction X is determined by the length of the gas outlet end of the gas pipe 200 extending beyond the gas outlet end of the combustion-supporting pipe 100. The structure of the mixing space 110 can be a cylindrical space, a flared space, a constricted space, or a stepped space, etc.

[0073] In some examples, when L1 / L2=1, the length of the distributor 300 is equal to the length of the mixing space 110, and the outlet end of the distributor 300 is flush with the outlet end of the mixing space 110. The raw coal gas, after being diverted by the distributor 300, immediately enters the mixing space 110 to mix with the combustion-supporting gas. The mixing path is short and the speed is fast, suitable for rapid combustion conditions. When L1 / L2=1.75, the length of the distributor 300 is greater than the length of the mixing space 110, and a portion of the distributor 300 is located within the mixing space 110. Within 10 minutes, the raw coal gas begins to mix with the combustion-supporting gas while being diverted, resulting in a longer mixing time and better mixing effect. When L1 / L2=2.5, the length of the distributor 300 is significantly greater than the length of the mixing space 110. Most of the section of the distributor 300 is located in the annular channel between the combustion-supporting pipe 100 and the coal gas pipe 200. After the raw coal gas is fully diverted and disturbed in the annular channel, it enters the mixing space 110 to mix with the combustion-supporting gas, resulting in the highest mixing uniformity. This is suitable for working conditions with extremely high requirements for combustion uniformity.

[0074] In this embodiment, the length L1 of the distributor 300 along the first direction X and the length L2 of the mixing space 110 along the first direction X satisfy 1≤L1 / L2≤2.5, ensuring that the raw coal gas can be fully diverted and disturbed before entering the mixing space 110, while ensuring that the mixing space 110 has sufficient volume and length for the raw coal gas and combustion-supporting gas to be fully mixed. The diversion effect of the distributor 300 and the mixing effect of the mixing space 110 are matched to each other, avoiding the problem of insufficient raw coal gas diversion due to L1 being too small or insufficient mixing time due to L2 being too small, and also avoiding the problem of excessive resistance due to L1 being too large or excessive mixing gas flow velocity due to L2 being too large. The reasonable ratio allows the raw coal gas to achieve deep mixing with the combustion-supporting gas in the mixing space 110 after being diverted and disturbed by the distributor 300, significantly improving the mixing uniformity, thereby ensuring sufficient and uniform combustion, reducing local high temperature and corrosion, extending the service life of the equipment, and ensuring that the furnace temperature of the pyrolysis furnace can be stably controlled within the range required by the process.

[0075] Embodiments of this application also provide a pyrolysis furnace, including the low-rank coal burner of the above embodiments.

[0076] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A low-rank coal burner, characterized in that, include: A combustion-supporting pipe, extending in the first direction, is used to introduce combustion-supporting gas; A gas pipe is fitted around the outer periphery of the combustion-supporting pipe for introducing raw coal gas. Along the first direction, the gas outlet of the gas pipe extends beyond the gas outlet of the combustion-supporting pipe to form a mixing space. A distributor is located between the combustion-supporting pipe and the gas pipe. The distributor is connected to the outer periphery of the gas outlet end of the combustion-supporting pipe. The distributor includes a plurality of deflector plates spaced apart circumferentially along the combustion-supporting pipe. Two adjacent deflector plates define a diversion channel. The diversion channel includes two air outlets arranged along a first direction. At least a portion of the deflector plates intersects the first direction. The deflector plates include a plurality of guide holes that penetrate along their own thickness direction.

2. The low-rank coal burner according to claim 1, characterized in that, The multiple redirection plates extend in parallel.

3. The low-rank coal burner according to claim 1, characterized in that, The redirecting plate includes a first bending portion and a second bending portion alternately arranged along the first direction. The bending directions of the first bending portion and the second bending portion along their own thickness direction are opposite. Both the first bending portion and the second bending portion have the flow guide hole.

4. The low-rank coal burner according to claim 3, characterized in that, In a plane perpendicular to the first direction, the first bend of one of two adjacent deflector plates overlaps with the second bend of the other deflector plate.

5. The low-rank coal burner according to claim 1, characterized in that, The redirection plate extends in a curved shape.

6. The low-rank coal burner according to claim 1, characterized in that, The redirecting plate includes a body portion and a cavity formed by the body portion. The body portion has openings at both ends along the length direction of the redirecting plate, and the guide holes are opened on both side walls of the body portion along the circumferential direction. Both the opening and the guide hole are connected to the cavity.

7. The low-rank coal burner according to claim 6, characterized in that, The plurality of flow guide holes include a first hole and a second hole, the first hole and the second hole being respectively opened on the two side walls of the body portion along the circumferential direction, and the first hole and the second hole being staggered.

8. The low-rank coal burner according to claim 1, characterized in that, The radial height of the redirecting plate along the gas pipe is H1, and the combustion-supporting pipe is coaxial with the gas pipe and the distance between them is H2, where 0.65≤H1 / H2≤1.

9. The low-rank coal burner according to claim 1, characterized in that, The length of the distributor along the first direction is L1, and the length of the mixing space along the first direction is L2, where 1 ≤ L1 / L2 ≤ 2.

5.

10. A pyrolysis furnace, characterized in that, The low-rank coal burner includes any one of claims 1 to 9.

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