Gas supply structure of internal heating type gas retort

Abstract

The invention relates to a gas supply structure of an internal heating type dry distillation furnace, a gas flow channel in a lattice wall is of a variable cross-section structure along the height direction and / or the longitudinal direction, so that the pressure distribution in the gas flow channel is more balanced; at least part of multiple layers of air distribution holes in the lattice wall are of a three-section structure with a reducing section, a throat section and an expansion section, the Rafael nozzle effect is achieved, the airflow kinetic energy and flame intensity of the air distribution hole area can be effectively enhanced, the phenomenon that air supply is insufficient at the tail end (especially the top of the tail end) of an airflow channel is prevented, and the service life of the airflow channel is prolonged. According to the semi-coke dry distillation device, sufficient and balanced combustion airflow can be obtained at all the air distribution holes, semi-coke is uniformly heated at each height section of the dry distillation area and is fully combusted, so that the semi-coke production efficiency and the product quality are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal dry distillation, and particularly relates to a gas supply structure of an internal heating dry distillation furnace. BACKGROUND

[0002] Coal dry distillation is to heat under the condition of air isolation, so that coal is thermally decomposed to generate semi-coke, coal tar and coal gas and other products. According to different heating methods, it can be divided into three types of internal heating, external heating and internal and external heating combination. Among them, the main feature of the internal heating dry distillation furnace is that the heat carrier directly contacts with the dry distillation raw material and product, and the heat carrier directly transmits heat to the coal material, which has low heat consumption and high thermal efficiency. According to the moving process of the coal material, the internal heating dry distillation furnace can be divided into three functional sections, namely, a drying section, a dry distillation section and a cooling section. The coal material enters the furnace from the top of the dry distillation furnace and moves downward, and the mixed gas of coal gas and air is supplied at the bottom of the dry distillation section, and the high-temperature gas generated after combustion is in countercurrent contact with the coal material to complete the coal dry distillation process.

[0003] The bottom of the dry distillation section of the internal heating dry distillation furnace is usually provided with a gas distribution wall, and the mixed gas enters the dry distillation area in the furnace through a plurality of gas distribution holes in the gas distribution wall. With the development of the internal heating dry distillation furnace in the direction of large-scale, the size of the furnace chamber is continuously increased (the furnace diameter is more than 2.5 meters), and the length of the gas distribution wall is also increased (more than 4 meters), so the mixed gas needs to be transported to each gas distribution hole along a long gas flow channel after entering the wall, and thus the problem of uneven gas distribution occurs. Near the gas inlet end of the mixed gas, the gas pressure is high, the gas supply is sufficient, and the flame is strong; while far away from the mixed gas inlet end (such as the end of the gas flow at the upper part of the wall), the flame is relatively weak due to the insufficient gas supply pressure, resulting in a lower temperature in the upper part of the dry distillation area. Ultimately, the coal material at different heights in the furnace is not uniformly heated, which directly affects the product quality and yield of the semi-coke, and in severe cases, it may even lead to insufficient carbonization or local over-coke.

[0004] In order to solve the problem of uneven gas supply of the large-scale internal heating dry distillation furnace, some technical solutions are provided in the prior art, some of which add gas distribution elements (such as gas distribution blocks and uniform distribution plates) in the gas flow channel in the wall to balance the gas flow of each part, and some of which install a nozzle type burner at each gas distribution hole to enhance the heating of the remote end of the gas flow channel by independent control. A Chinese patent application with the publication number CN120025840A discloses a dry distillation furnace group with multi-layer gas supply and a gas supply method thereof, in which the cross-sectional area of the outlet of each gas supply channel decreases successively along the direction of mixed gas transportation, that is, the cross-sectional area of the outlet of the gas supply channel near the mixed gas inlet is greater than that of the outlet of the gas supply channel far away from the mixed gas inlet, so as to maximize the uniformity of the gas supply.

[0005] However, the above solutions have limited effect on improving the uniformity of gas distribution, and some even increase the complexity of the furnace structure and manufacturing cost. Especially when applied to large internal heating dry distillation furnaces, it is difficult to ensure that all gas distribution holes can obtain sufficient and balanced combustion airflow. Summary of the Invention

[0006] This invention provides a gas supply structure for an internally heated dry distillation furnace. The airflow channels within the decorative wall adopt a variable cross-section structure, making the pressure distribution within the airflow channels more balanced. At least part (or all) of the multi-layered air distribution holes on the decorative wall adopt a three-section structure with a "constriction section - throat section - expansion section," which has a Laval nozzle effect. This effectively enhances the kinetic energy of the airflow in the air distribution hole area and the flame intensity, preventing insufficient gas supply at the end of the airflow channel (especially at the top of the end). This ensures that sufficient and balanced combustion airflow is obtained at all air distribution holes, and that the semi-coke is heated evenly and burned completely at all heights in the dry distillation zone, thereby improving the production efficiency and product quality of semi-coke.

[0007] To achieve the above objectives, the present invention employs the following technical solution: A gas supply structure for an internally heated retort furnace includes several decorative walls within the furnace. Each decorative wall has an airflow channel, the outer end of which is connected to a mixed gas inlet located on one side of the furnace. Multiple air distribution holes on the decorative walls are connected to their respective airflow channels. The airflow channels have variable cross-sections along their height and / or longitudinal direction. Along the height direction, the cross-sectional area gradually decreases from bottom to top. Along the longitudinal direction, the cross-sectional area gradually decreases from the mixed gas inlet towards the furnace interior. At least some of the air distribution holes are variable cross-section holes, each with a contraction section, a throat section, and an expansion section sequentially along the airflow direction.

[0008] The flower wall has a partition wall in the middle of its longitudinal direction, that is, there are two parallel airflow channels in the same flower wall, and air distribution holes are opened on one side of each airflow channel; the partition wall in the middle of each airflow channel divides the airflow channel into two independent channels in the longitudinal direction.

[0009] The inner wall profile of the axial section of the variable cross-section air distribution hole has a Laval curve shape.

[0010] The air distribution holes are arranged in multiple rows and columns on the flower wall, with adjacent rows of air distribution holes staggered in the horizontal direction.

[0011] Several flow regulating plates are installed inside the airflow channel, and through holes are opened on the flow regulating plates.

[0012] The airflow channel is provided with some flow disturbance components, which are protrusions or guide plates fixed on the inner wall of the airflow channel.

[0013] The airflow channel is equipped with both a flow regulating plate and a flow deflector.

[0014] The mixed gas inlet is located at the lower part of the airflow channel, and the flow regulating plate is located at the upper part of the airflow channel.

[0015] The flower wall is a monolithic flower wall made of refractory material.

[0016] The flower wall is a segmented structure along its height and / or longitudinal direction, and is assembled from multiple prefabricated refractory material modules to form an integral structure.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1) Uniform airflow distribution: The present invention designs the airflow channel in the flower wall with a variable cross-section channel structure along the height and / or longitudinal direction, and supplements it with air distribution holes with a special opening form (with a Laval nozzle structure), which ensures that the pressure distribution of the mixed gas is more uniform throughout the entire length and height of the airflow channel, and the flame intensity ejected from the air distribution holes at various locations tends to be consistent, which significantly improves the problem of uneven heating of semi-coke in large vertical furnaces, and makes the temperature field in the upper and lower parts of the dry distillation zone more uniform.

[0018] 2) Improved combustion efficiency: The airflow distribution into the vertical furnace is more rational, avoiding localized oxygen-rich or oxygen-deficient combustion, allowing for full combustion and utilization of the coal gas, thus improving thermal efficiency. The semi-coke is fully dry-distilled at a uniform temperature, resulting in more stable quality semi-coke with lower volatile matter content, and improved burnout rates of combustible components such as furnace gas and carbon monoxide.

[0019] 3) Adaptability to large furnace types: The gas supply structure described in this invention is particularly suitable for internally heated retorts with a furnace diameter greater than 2.5 meters and a grate height exceeding 4 meters. Even in large furnaces with an annual processing capacity of no less than 100,000 tons of semi-coke, it can still ensure uniform heating in all parts of the retort zone, solving the bottleneck problem encountered by traditional gas supply structures in large furnaces and providing reliable technical support for the industrial application of large internally heated retorts.

[0020] 4) Reliable structure and long service life: Due to the uniform heat flow distribution of each air distribution hole, the heating of the flower wall body is also more uniform, avoiding the burning of refractory materials caused by local overheating and extending the overall service life of the gas supply structure. When the flower wall structure adopts an integrated structure, it has good airtightness and is not prone to cracks and air leakage; when adopting a modular structure, it is convenient to replace damaged units, simplify maintenance, and can significantly reduce the shutdown maintenance time.

[0021] 5) Flexible and controllable operation: By further setting flow regulating plates and turbulence-disrupting components in the airflow channel, the airflow distribution can be finely adjusted and controlled according to actual needs (for example, the flow velocity distribution of the airflow in the airflow channel can be adjusted according to changes in coal type or load to maintain the stability of the temperature field inside the furnace). The entire gas supply system has high controllability, which is conducive to maintaining good operating performance of the internal heating dry distillation furnace under different operating conditions. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the gas supply structure of an internally heated dry distillation furnace according to the present invention.

[0023] Figure 2 This is a mid-section view of the gas supply structure of an internally heated dry distillation furnace according to the present invention.

[0024] Figure 3 This is a schematic diagram of the air distribution holes described in this invention.

[0025] Figure 4 This is a schematic diagram of a flow regulating plate installed in the airflow channel of the present invention.

[0026] Figure 5 This is a schematic diagram of a baffle installed in the airflow channel of the present invention.

[0027] In the diagram: 1. Dry distillation zone 2. Flower wall 21. Mixed gas inlet 22. Gas distribution hole 22-1. Contraction section 22-2. Throat section 22-3. Expansion section 23. Airflow channel 3. Feed channel 4. Flow regulating plate 5. Baffle element Detailed Implementation

[0028] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings: See Figure 1 , Figure 2 As shown, the gas supply structure of the internally heated retort furnace of the present invention includes several decorative walls 2 disposed in the internally heated retort furnace. Each decorative wall 2 has an airflow channel 23. The outer end of each airflow channel 23 is connected to a mixed gas inlet 21 located on one side of the internally heated retort furnace. Multiple air distribution holes 22 on the decorative walls 2 are respectively connected to the corresponding airflow channels 23. The airflow channels 23 have a variable cross-section structure along the height and / or longitudinal direction. The variable cross-section structure along the height direction means that the cross-sectional area of ​​the airflow channel 23 gradually decreases from bottom to top. The variable cross-section structure along the longitudinal direction means that the cross-sectional area of ​​the airflow channel 23 gradually decreases from the mixed gas inlet 21 towards the furnace interior. At least some of the air distribution holes 22 are variable cross-section air distribution holes, such as… Figure 3 As shown, the variable cross-section air distribution hole is provided with a contraction section 22-1, a throat section 22-2 and an expansion section 22-3 in sequence along the airflow direction.

[0029] The flower wall 2 has a partition wall in the middle of its longitudinal direction, that is, there are two parallel airflow channels 23 in the same flower wall 2, and air distribution holes 22 are opened on one side of each airflow channel 23; the partition wall in the middle of each airflow channel 23 divides the airflow channel 23 into two independent channels in the longitudinal direction.

[0030] The inner wall profile of the axial section of the variable cross-section air distribution hole has a Laval curve shape.

[0031] The air distribution holes 22 are arranged in multiple rows and columns on the flower wall, with adjacent rows of air distribution holes staggered in the horizontal direction.

[0032] like Figure 4 As shown, several flow regulating plates 4 are provided in the airflow channel 23, and through holes are opened on the flow regulating plates 4.

[0033] like Figure 5 As shown, the airflow channel 23 is provided with a flow disturbance element 5, which is a protrusion or guide plate fixed on the inner wall of the airflow channel 23.

[0034] The airflow channel 23 is equipped with a flow regulating plate 4 and a flow disturbance component 5.

[0035] The mixed gas inlet 21 is located at the lower part of the airflow channel 23, and the flow regulating plate 4 is located at the upper part of the airflow channel 23.

[0036] The flower wall 2 is an integral flower wall made of refractory material.

[0037] The flower wall 2 is a segmented structure along the height and / or longitudinal direction, and is formed by assembling multiple prefabricated refractory material modules to form an integral structure.

[0038] The present invention discloses a gas supply structure for an internally heated retort furnace, comprising multiple concentric walls 2 arranged parallel to each other in the lower part of the retort zone 1 of the internally heated retort furnace (vertical furnace), forming multiple feeding channels between the concentric walls 2. A longitudinal airflow channel 23 is arranged within the concentric walls 2 for supplying a mixture of coal gas and air into the furnace. One end of the airflow channel 23 is connected to a mixed gas inlet 21. Multiple gas distribution holes 22 are provided on both sides of the concentric walls 2 facing the retort zone 1, and the gas distribution holes 22 communicate with corresponding airflow channels 23 to introduce the mixed gas within the airflow channels 23 into the retort zone 1 for heating and combustion.

[0039] The difference between this invention and the prior art lies in the fact that the airflow channel 23 adopts a variable cross-section structure along the height and / or longitudinal direction (airflow direction), and the cross-sectional area gradually decreases from bottom to top, or from the mixed gas inlet 21 towards the furnace, forming a tapered channel structure that gradually narrows from wide to narrow. Through the variable cross-section airflow channel 23, the pressure distribution of the mixed gas flow within the airflow channel 23 becomes more balanced. Even when the airflow channel 23 is high and long, it ensures sufficient gas supply to the area far from the mixed gas inlet 21 (the end of the airflow channel), especially the top area, significantly improving the problem of uneven airflow distribution.

[0040] In addition, the air distribution holes 22 on the flower wall 2 of the present invention can be wholly or partially (such as in the upper part or end of the airflow channel 23) using variable cross-section air distribution holes with a Laval nozzle structure. The variable cross-section air distribution holes are composed of a contraction section 22-1, a throat section 22-2 and an expansion section 22-3 along the axial direction. The function of using variable cross-section air distribution holes is to accelerate the airflow of the mixed gas in the throat section 22-2, and then form a high-speed jet into the furnace through the expansion section 22-3, thereby enhancing the airflow energy and flame intensity near the corresponding air distribution holes 22, and further preventing the possible insufficient gas supply at the end of the airflow channel 23.

[0041] The air distribution holes 22 on the flower wall 2 are typically arranged in multiple layers (rows) along the height direction. Preferably, two adjacent layers of air distribution holes are staggered in the horizontal direction (staggered by a distance). Through the multi-layered and staggered arrangement, the flames emitted from the air distribution holes 22 at different heights cover a wider and more uniform range within the dry distillation zone 1, avoiding direct overlap of the flame streams from the upper and lower layers of air distribution holes on the same vertical line. This helps to improve the uniformity of the heat treatment of the semi-coke by the lateral introduction of flames from the flower wall 2.

[0042] Preferably, a flow regulating plate 4 can be installed within the airflow channel 23 of the present invention. The flow regulating plate 4 can be a throttling plate with through holes, fixedly or detachably installed at a set position within the airflow channel 23, used to reduce the gas flow area at the installation location, thereby controlling the gas flow rate through that location. In the present invention, one or more flow regulating plates 4 can be set as needed to finely adjust the flow distribution at different positions in the airflow channel, achieving more precise gas distribution and improving gas distribution balance. By adjusting the diameter of the through holes on the flow regulating plate 4 or the opening of the flow regulating plate 4, the pressure difference between the near end and the far end of the airflow channel 23 can be balanced, preventing excessive combustion gas from prematurely ejecting from the gas distribution hole 22 near the mixed gas inlet 21, ensuring that there is always sufficient airflow at the end of the airflow channel 23.

[0043] Preferably, the airflow channel 23 of the present invention may also be provided with a turbulence-disrupting element 5 (such as a guide vane, protrusion, etc.) to disrupt the streamline shape of the internal airflow, increase the degree of turbulence, make the mixing of gas and air in the airflow channel 23 more complete, and prevent the airflow from deviating along one side of the channel wall. By providing the turbulence-disrupting element 5, it can be ensured that the mixed gas in the airflow channel 23 is homogeneous and has stable pressure before reaching each gas distribution hole 22, thereby making the flame intensity ejected from each gas distribution hole 22 more similar, and further improving the uniformity and stability of combustion heating.

[0044] Preferably, the flower wall 2 of this invention can be integrally formed using refractory materials with high refractory performance, such as by casting refractory castable in one piece, or by firing prefabricated refractory bricks into an integral flower wall structure in a kiln. The integrally formed structure avoids internal splicing gaps, provides good airtightness and high strength, and can be used for a long time at high temperatures without easily deforming or being damaged. Alternatively, the flower wall 2 can also be constructed by assembling several prefabricated refractory material modules. That is, the flower wall adopts a segmented splicing structure, with each refractory material module connected by mortise and tenon joints or interlocking mechanisms. The internal channels of each refractory material module are aligned to form a complete variable cross-section airflow channel. The modular design facilitates the manufacturing, transportation, and installation of the flower wall structure. The length and height of the flower wall can be adjusted by flexibly increasing or decreasing the number of refractory material modules according to the furnace size. Disassembly and assembly are convenient, and when a refractory material module is damaged, it can be replaced individually, thereby reducing maintenance costs.

[0045] To more intuitively illustrate the present invention, the embodiments of the present invention will be further described in conjunction with the examples. The following examples are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technical solutions that can be obviously obtained by those skilled in the art within the scope of the technology disclosed in the present invention, including simple variations or equivalent substitutions, are all within the scope of protection of the present invention.

[0046]

Example 1

[0047] One end of the airflow channel 23 is connected to the mixed gas inlet 21, through which the mixture of coal gas and air enters the airflow channel 23. The gas distribution holes 22 penetrate the side wall of the flower wall body and connect to the dry distillation zone 1 inside the furnace. When the mixed gas flows through the airflow channel 23, it is laterally injected into the dry distillation zone 1 through each gas distribution hole 22, forming flames around the coal layer in the feeding channel to heat and dry distill the falling coal.

[0048] In this embodiment, the cross-sectional area of ​​the airflow channel 23 gradually decreases along the height direction. Specifically, the bottom surface of the airflow channel 23 gradually rises as it extends inward. The inner wall of one side of the flower wall 2 also has a certain inclination angle, that is, the width of the airflow channel 23 also gradually decreases from the mixed gas inlet 21 towards the furnace.

[0049] In this embodiment, the airflow channel 23 has a stepped structure along the longitudinal direction, that is, the airflow channel 23 is divided into several segments along the longitudinal direction, and the cross-sectional area of ​​each segment decreases sequentially. Compared with a continuously decreasing structure, it can also play the role of airflow balance and pressure balance.

[0050] In this embodiment, all the air distribution holes 22 on the flower wall 2 have a Laval nozzle structure, such as Figure 3 As shown, the end of the gas distribution hole corresponding to the gas inflow direction is a contraction section 22-1, the middle part of the gas distribution hole 22 is a throat section 22-2 with the smallest cross-section, and the end of the gas distribution hole 22 corresponding to the gas outflow direction is an expansion section 22-3. This "contraction-throat-expansion" gas distribution hole structure forms a structure similar to a Laval nozzle. When the mixed gas reaches the narrow throat section 22-2, the airflow velocity increases and the pressure decreases. Then, it expands rapidly when passing through the expansion section 22-3, and finally is ejected at high speed through the gas distribution hole 22. On the one hand, this structure ensures that even if the amount of mixed gas remaining at the end of the gas channel 23 is small, its ejection velocity and momentum can be enhanced. On the other hand, the presence of the expansion section 22-3 helps to guide the high-speed airflow towards the direction of the dry distillation zone 1, increasing the flame penetration depth ejected from the gas distribution hole 22 at the end of the airflow channel 23. Through the above design, the combustion intensity at the top of the end of the flower wall 2 is significantly improved, solving the problem of weak flame at the end of the flower wall, especially at the top end, in conventional gas supply structures.

[0051] In this embodiment, the air distribution holes 22 on the flower wall 2 are arranged in three layers along the height, with several holes in each layer. The three layers of air distribution holes are arranged horizontally in a staggered manner. Specifically, taking the air distribution holes of the middle layer as a reference, the air distribution holes of the lower and upper layers are staggered by half a hole distance from the corresponding air distribution holes of the middle layer. In this way, the flame jet on the side wall of the flower wall 2 achieves a "staggered" distribution in the vertical direction. The flames from the holes distributed in different layers can cover different cross-sectional positions in the carbonization chamber, eliminating the local overheating caused by the direct overlap between two adjacent layers of flames, and making the heating of the semi-coke more even. In this embodiment, the size of each air distribution hole 22 is the same (in specific applications, the diameter of the upper layer air distribution holes far from the mixed gas inlet 21 can be appropriately increased according to the pressure drop along the airflow channel 23). Pressure equalization is mainly achieved through the variable cross-section airflow channel 23, and construction is also simpler.

[0052]

Example 2

[0053] In this embodiment, the flow regulating plate 4 is installed above the mixed gas inlet 21, occupying the upper 1 / 3 of the height of the airflow channel 23, via a heat-resistant mounting bracket. The airflow entering from the lower part of the airflow channel 23 encounters local resistance at this position, causing some airflow to stagnate and the pressure to increase. This helps more mixed gas to continue being transported upwards to the upper part of the airflow channel 23, effectively balancing the flow distribution between the lower and upper parts of the airflow channel and preventing excessive flame ejection from the lower air distribution holes 22 of the flower wall 2 due to excessively high airflow pressure. Simultaneously, the high-speed airflow around the through holes generates vortices behind the flow regulating plate 4, which also helps to enhance the turbulence and mixing effect of the airflow.

[0054] As an alternative, the flow regulating plate 4 can also be designed as a replaceable or adjustable opening structure, such as a plate with an adjustable opening ratio through a slot insertion and removal structure, or an opening adjusted by a rotation mechanism, to adapt to the requirements of airflow distribution under different working conditions.

[0055]

Example 3

[0056] The form of the baffle 5 is not limited to a protrusion; it can be used as long as it can effectively disturb the airflow without significantly increasing resistance. By setting the baffle 5, it can be ensured that the airflow parameters (concentration, pressure, velocity) are more consistent before the airflow reaches each air distribution hole 22, thereby ensuring that the flame ejected from each air distribution hole 22 is stable and balanced.

[0057]

Example 4

[0058] Integrated flower walls offer advantages such as smooth airflow channels, precise dimensions, high overall strength, and resistance to heat and erosion. During use, the integrated flower wall structure is less prone to air leakage and can withstand the erosion and heat circulation of burning flames for extended periods while maintaining structural integrity.

[0059]

Example 5

[0060] In this embodiment, the flower wall 2 is composed of three refractory material modules: lower, middle, and upper. The cross-section of the airflow channels inside the three refractory material modules decreases sequentially from large to small. After the refractory material modules are stacked to form the flower wall 2, an airflow channel 23 that gradually narrows from bottom to top is formed. The three refractory material modules are connected and fixed with heat-resistant mortar and metal anchors to ensure a tight fit at the joints and prevent air leakage.

[0061] The advantages of modular design lie in its ease of production and transportation: individual refractory modules are relatively small in size, allowing for mass production in the factory and easy quality control; on-site installation simply requires stacking them one by one, resulting in a short construction cycle. Furthermore, if any part of the decorative wall is damaged, only the corresponding refractory module needs to be replaced for restoration, eliminating the need for complete demolition and reconstruction, thus reducing maintenance costs. This modular assembly scheme offers great flexibility for large furnace types, allowing for flexible combinations based on different furnace diameters and heights, making it suitable for semi-coke production lines with varying annual production capacities.

[0062] After implementing the above embodiments, the temperature deviation of each layer of semi-coke in the internally heated dry distillation furnace was controlled within ±20℃, which is far superior to the traditional structure (above ±50℃). After a period of application, no coking (insufficient carbonization) occurred in the top semi-coke, and no over-coking or sintering occurred in the bottom semi-coke, resulting in stable product quality. At the same time, gas consumption was reduced by about 5%, demonstrating higher thermal utilization efficiency.

[0063] Therefore, the gas supply structure described in this invention is particularly suitable for the gas supply requirements of large vertical furnaces. It can effectively improve the uniformity of airflow and temperature distribution in the furnace through structural optimization without increasing additional energy consumption and complex equipment, and has significant economic benefits and industrial application value.

[0064] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A gas supply structure for an internally heated retort furnace, comprising a plurality of decorative walls disposed within the furnace, each decorative wall having an airflow channel, the outer end of which is connected to a mixed gas inlet located on one side of the furnace, and a plurality of gas distribution holes on the decorative walls respectively connected to corresponding airflow channels; characterized in that, The airflow channel has a variable cross-section structure along the height and / or longitudinal direction. The variable cross-section structure along the height direction means that the cross-sectional area of ​​the airflow channel gradually decreases from bottom to top. The variable cross-section structure along the longitudinal direction means that the cross-sectional area of ​​the airflow channel gradually decreases from the mixed gas inlet to the furnace. At least some of the gas distribution holes are variable cross-section gas distribution holes, which are provided with a contraction section, a throat section and an expansion section in sequence along the airflow direction.

2. The gas supply structure of an internally heated dry distillation furnace according to claim 1, characterized in that, The flower wall has a partition wall in the middle of its longitudinal direction, that is, there are two parallel airflow channels in the same flower wall, and air distribution holes are opened on one side of each airflow channel; the partition wall in the middle of each airflow channel divides the airflow channel into two independent channels in the longitudinal direction.

3. The gas supply structure of an internally heated dry distillation furnace according to claim 1, characterized in that, The inner wall profile of the axial section of the variable cross-section air distribution hole has a Laval curve shape.

4. The gas supply structure of an internally heated dry distillation furnace according to claim 1, characterized in that, The air distribution holes are arranged in multiple rows and columns on the flower wall, with adjacent rows of air distribution holes staggered in the horizontal direction.

5. The gas supply structure of an internally heated dry distillation furnace according to claim 1, characterized in that, Several flow regulating plates are installed inside the airflow channel, and through holes are opened on the flow regulating plates.

6. The gas supply structure of an internally heated dry distillation furnace according to claim 1, characterized in that, The airflow channel is provided with some flow disturbance components, which are protrusions or guide plates fixed on the inner wall of the airflow channel.

7. The gas supply structure of an internally heated dry distillation furnace according to claim 1, characterized in that, The airflow channel is equipped with both a flow regulating plate and a flow deflector.

8. The gas supply structure of an internally heated dry distillation furnace according to claim 1, characterized in that, The mixed gas inlet is located at the lower part of the airflow channel, and the flow regulating plate is located at the upper part of the airflow channel.

9. The gas supply structure of an internally heated dry distillation furnace according to claim 1, characterized in that, The flower wall is a monolithic flower wall made of refractory material.

10. The gas supply structure of an internally heated dry distillation furnace according to claim 1, characterized in that, The flower wall is a segmented structure along its height and / or longitudinal direction, and is assembled from multiple prefabricated refractory material modules to form an integral structure.

Images