Roasting device for recycling cold rolling pickling waste liquid

Abstract

The invention provides a cold rolling pickling waste liquid recycling roasting device, and relates to the technical field of pickling waste liquid treatment.The roasting device comprises a furnace body, an outer frame, a furnace cover part, a furnace bottom discharging structure and a preheating combustion furnace, the inner wall of the furnace body is lined with a refractory material, and the furnace cover part is provided with an atomization feeding structure and a waste gas pipeline; the atomization feeding structure atomizes and sprays waste acid liquid into the furnace, a plurality of flow aiding structures are arranged on the side wall of the furnace body, each flow aiding structure is distributed in the circumferential direction to form an annular array, the preheating combustion furnace is provided with a plurality of independent combustion chambers, and the combustion chambers are tangentially connected with the side wall of the furnace body through high-temperature gas guide pipes, so that high-temperature gas forms high-temperature rotational flow in the furnace. And the waste acid liquid fog drops are fully contacted and mixed in the high-temperature rotational flow. The gas-solid contact time is effectively prolonged, the reaction efficiency and roasting sufficiency are improved, uniform distribution of the temperature in the furnace is achieved, local overheating is avoided, and the resource utilization effect of the waste acid solution is improved.

Description

Technical Field

[0001] This invention relates to the field of pickling waste liquid treatment technology, and in particular to a roasting apparatus for the reuse of cold rolling pickling waste liquid. Background Technology

[0002] Cold rolling pickling wastewater is acidic wastewater generated during the cold rolling process of steel, mainly containing hydrochloric acid, ferrous chloride, and small amounts of grease and suspended solids. With increasingly stringent environmental protection requirements, the resource-based treatment of waste acid has become an important issue. Calcination is currently the mainstream technology for treating pickling wastewater, decomposing ferrous chloride into iron oxide powder and hydrogen chloride gas at high temperatures, thus achieving resource utilization of the wastewater.

[0003] Existing roasting devices typically employ rotary kilns or fluidized bed structures, which suffer from problems such as insufficient gas-solid contact, uneven temperature distribution, localized overheating, and low reaction efficiency. Some devices introduce high-temperature gas flow through a single inlet, making it difficult to form a stable vortex, resulting in short droplet residence time and incomplete roasting. Furthermore, traditional devices lack effective vortex enhancement structures, causing rapid attenuation of vortex intensity during axial gas flow, affecting reaction uniformity and product quality. Therefore, it is necessary to develop a roasting device with a reasonable structure, stable vortex, and uniform temperature to improve the efficiency of waste acid treatment and resource recovery. Summary of the Invention

[0004] The purpose of this invention is to provide a roasting apparatus for the reuse of cold rolling pickling waste liquid, so as to solve the technical problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A roasting device for recycling cold-rolled pickling waste liquid includes a furnace body, an outer frame, a furnace cover, a furnace bottom discharge structure, and a preheating combustion furnace. The furnace body is mounted on the outer frame, and its inner wall is lined with refractory material. The furnace cover is located at the top of the furnace body, and its outer wall is provided with an atomizing feed structure and a waste gas pipe for drawing out the gaseous products inside the furnace body. The liquid outlet end of the atomizing feed structure extends into the furnace body to atomize the waste acid liquid and spray it into the furnace. The conical bottom of the atomizing feed structure is provided with a discharge pipe, and the discharge pipe is connected to the furnace bottom discharge structure.

[0007] The furnace body has multiple flow-aiding structures on its sidewalls, which are divided into multiple groups. These groups are spaced apart along the axial direction of the furnace body, and the flow-aiding structures within each group are distributed circumferentially along the furnace body, forming a ring array. The preheating combustion furnace is mounted on the outer frame and has multiple independent combustion chambers. Each combustion chamber is connected to a high-temperature gas guide pipe. The end of the high-temperature gas guide pipe away from the preheating combustion furnace is tangentially connected to the sidewall of the furnace body, causing the high-temperature gas to form a high-temperature vortex inside the furnace body. The connection point between the high-temperature gas guide pipe and the furnace body is at the same height as one group of flow-aiding structures. The flow-aiding structures in each group are configured to provide unidirectional auxiliary airflow to the high-temperature vortex to increase the vortex intensity and stability of the high-temperature vortex during axial flow.

[0008] Based on the above technical solutions, the present invention also provides the following optional technical solutions:

[0009] In one alternative: the high-temperature swirls introduced into the main body of the furnace by two adjacent high-temperature gas guide pipes have opposite swirl directions.

[0010] In one alternative embodiment: the outer wall of the furnace body has multiple flow-aiding ports corresponding to the flow-aiding structures. Each flow-aiding structure includes a flow-aiding hood, a flow-aiding main shaft, and flow-aiding blades. The flow-aiding hood is installed on the outside of the corresponding flow-aiding port and seals it. The flow-aiding main shaft is rotatably located inside the flow-aiding hood, with both its upper and lower ends extending to the outside of the flow-aiding hood. The flow-aiding blades are fixed on the flow-aiding main shaft and can pass through the flow-aiding ports into the interior of the furnace body. The outer wall of the furnace body is provided with multiple synchronous connectors, which are connected to the ends of the flow-aiding hoods in the multiple flow-aiding structures to realize the motion transmission between the multiple flow-aiding hoods in each group of flow-aiding structures. One of the flow-aiding hoods in each group of flow-aiding structures is connected to a flow-aiding motor.

[0011] In one alternative: a gear is provided at the end of the flow-aiding main shaft, and the synchronous connector includes a rotating ring and a gear ring. The rotating ring is located on the outer wall of the furnace body and can rotate around the axis of the furnace body. The gear ring is fixed on the rotating ring and meshes with multiple gears located in the same group.

[0012] In one alternative: a guide cone filter plate is further provided on the inner wall of the furnace cover, and an exhaust ring cavity is formed between the guide cone filter plate and the furnace cover; the atomizing feed structure is a high-speed centrifugal atomizer, and the atomizing disc at its lower end passes through the center of the guide cone filter plate, extends to the bottom of the guide cone filter plate and contacts its surface; the exhaust gas pipe is connected to the exhaust ring cavity through the outlet of the outer wall of the furnace cover.

[0013] In one alternative embodiment: the discharge pipe is further provided with a vibration structure, which includes a vibrating main rod and a vibrator. The vibrating main rod is arranged along the axis of the main body of the furnace, and its top extends to the conical bottom area of ​​the main body of the furnace. The vibrator is arranged at the bottom of the flow aid inlet and connected to the bottom of the vibrating main rod. Multiple guide rods are arranged on its outer wall along the axis of the vibrating main rod, and multiple vibrating arc rods are arranged on the part of the vibrating main rod located in the conical bottom area of ​​the main body of the furnace. The vibrating arc rods are arranged along the conical bottom of the main body of the furnace.

[0014] In one alternative embodiment: the furnace bottom discharge structure includes a cylindrical outer shell, a feed pipe, a circulating cooler, and a screw conveyor body. The cylindrical outer shell is further provided with a cylindrical inner shell, and a cooling chamber is formed between the cylindrical inner shell and the cylindrical outer shell. One end of the feed pipe is connected to the discharge pipe, and the other end passes through the outer wall of the cylindrical outer shell and the cooling chamber, communicating with the inside of the cylindrical inner shell. The screw conveyor body is located inside the cylindrical inner shell and is used to transport the material introduced by the feed pipe to the subsequent cooling system. The circulating cooler is located on the outside of the cylindrical outer shell, and its air inlet and outlet are respectively connected to the two ends of the cylindrical outer shell through circulating air pipes and communicate with the cooling chamber.

[0015] In one alternative: a spiral partition is further provided on the outer wall of the cylindrical inner shell, the edge of the spiral partition is in contact with the inner wall of the cylindrical outer shell, and the spiral partition divides the cooling chamber into a spiral state along the axis of the cylindrical inner shell.

[0016] By adopting the above technical solution, the present invention has the following beneficial effects:

[0017] This invention utilizes multiple independent combustion chambers and tangentially arranged high-temperature gas guide pipes in a preheating combustion furnace to create a high-temperature swirling flow within the furnace body. Combined with multiple sets of circumferentially distributed flow-aiding structures providing unidirectional auxiliary airflow, this significantly enhances the swirling flow intensity and stability, prolongs the gas-solid contact time, and improves reaction efficiency and calcination completeness. The multiple flow-aiding structures and high-temperature gas guide pipes are arranged at different heights to achieve stratified introduction of high-temperature airflow, ensuring uniform axial temperature distribution within the furnace, avoiding localized overheating, and improving reaction uniformity and product quality. The device is compact, operates continuously, and is suitable for industrial-scale applications, effectively realizing the resource utilization of cold rolling pickling wastewater, and exhibiting significant economic and environmental benefits. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the roasting device for recycling cold rolling pickling waste liquid in this invention.

[0020] Figure 2 This is a schematic diagram of the internal structure of the furnace body in one embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of a flow-aiding structure in one embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the furnace cover structure in one embodiment of the present invention.

[0023] Figure 5 This is a schematic diagram of a vibration structure in one embodiment of the present invention.

[0024] Figure 6 This is a schematic diagram of the furnace bottom discharge structure in one embodiment of the present invention.

[0025] Figure 7 This is a schematic diagram of the internal structure of the furnace bottom discharge structure in one embodiment of the present invention.

[0026] Figure reference numerals: Furnace body 100, discharge pipe 110, flow aid inlet 120, vibration structure 130, main vibrating rod 131, guide rod 132, vibrating arc rod 133, vibrator 134, outer frame 200, furnace cover 300, guide cone filter plate 310, exhaust ring cavity 320, furnace bottom discharge structure 400, cylindrical outer shell 410, feed pipe 420, circulating cooler 430, circulating gas pipe 4 31. Screw conveyor body 440, cylindrical inner shell 450, spiral partition 460, cooling chamber 470, preheating combustion furnace 500, high temperature gas guide pipe 510, flow aid structure 600, flow aid hood 610, flow aid main shaft 620, flow aid blade 630, flow aid motor 640, rotating ring 650, gear ring part 660, gears 670, 680, 690, exhaust gas pipe 700, atomizing feed structure 800. Detailed Implementation

[0027] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The left, right, up, and down positions of the various components shown in the attached diagram are just one arrangement method; the specific positions should be set according to specific needs.

[0029] In one embodiment, such as Figure 1 and Figure 2As shown, a cold rolling pickling waste liquor recycling roasting device includes a furnace body 100, an outer frame 200, a furnace cover 300, a furnace bottom discharge structure 400, and a preheating combustion furnace 500. The furnace body 100 is mounted on the outer frame 200, and its inner wall is lined with refractory material. The furnace cover 300 is located at the top opening of the furnace body 100, and its outer wall is provided with an atomizing feed structure 800 and a waste gas pipe 700 for drawing out the gaseous products inside the furnace body 100. The liquid outlet end of the atomizing feed structure 800 extends into the furnace body 100 to atomize the waste acid liquid and spray it into the furnace. The conical bottom of the atomizing feed structure 800 is provided with a discharge pipe 110, and the discharge pipe 110 is connected to the furnace bottom discharge structure 400.

[0030] The furnace body 100 has multiple flow-aiding structures 600 on its sidewalls. These flow-aiding structures 600 are divided into multiple groups on the sidewalls of the furnace body 100. The multiple groups are spaced apart along the axial direction of the furnace body 100, and the flow-aiding structures 600 in each group are distributed circumferentially along the furnace body 100, forming a ring array. The preheating combustion furnace 500 is mounted on the outer frame 200 and has multiple independent combustion chambers. Each combustion chamber is connected to a high-temperature gas guide pipe 510. The end of the high-temperature gas guide pipe 510 away from the preheating combustion furnace 500 is tangentially connected to the sidewall of the furnace body 100, so that the high-temperature gas forms a high-temperature vortex inside the furnace body 100. The connection point between the high-temperature gas guide pipe 510 and the furnace body 100 is at the same height as one of the flow-aiding structures 600 in one group. The flow-aiding structures 600 in each group are configured to provide unidirectional auxiliary airflow to the high-temperature vortex to increase the vortex intensity and stability of the high-temperature vortex during axial flow.

[0031] In this embodiment of the invention, the waste acid liquid, after being pretreated by a pretreatment system to remove suspended solids, oil, and mechanical impurities, is sent to the atomizing feed structure 800 via a feed pump and pipeline. The atomizing feed structure 800 atomizes the waste acid liquid, forming fine droplets that are sprayed into the furnace body 100. Simultaneously, each combustion chamber of the preheating combustion furnace 500 is burned synchronously, and the high-temperature gas generated is sent into the furnace body 100 via a high-temperature gas guide pipe 510, generating a high-temperature vortex inside the furnace body 100. As the droplets fall from the top of the furnace body 100, they fully contact and mix with the high-temperature vortex, and the moisture on the surface of the droplets evaporates instantly. The ferrous chloride contained in the droplets undergoes a decomposition reaction at high temperature, and the generated iron oxide powder is a solid particle. Due to gravity, it settles and accumulates in the conical bottom area of ​​the furnace body 100, and is finally guided to the furnace bottom discharge structure 400 by the discharge pipe 110. The bottom discharge structure 400 continuously discharges the material, which is then cooled by the cooling drum to become the product. High-temperature gas exists in a swirling manner inside the furnace body 100, allowing for thorough contact and mixing with the droplets. Furthermore, with the assistance of multiple flow-aiding structures 600, the swirling intensity and stability of the high-temperature gas during axial flow are greatly enhanced, prolonging the gas-solid residence time, improving reaction efficiency, and resulting in more complete droplet roasting. The preheating combustion furnace 500 introduces high-temperature gas flow into the furnace body 100 through multiple air inlets. These inlets correspond to multiple sets of flow-aiding structures 600, achieving the introduction of high-temperature gas flow at different heights to ensure uniform temperature along the furnace body 100's internal axis and prevent localized overheating. The exhaust gas generated after droplet roasting is discharged through the exhaust pipe 700. The refractory material can be hydrochloric acid-resistant ceramic bricks or castables to ensure the service life of the furnace body 100.

[0032] In one embodiment, such as Figure 1 and Figure 2 As shown, the high-temperature swirling streams introduced into the furnace body 100 by two adjacent high-temperature gas guide pipes 510 have opposite rotation directions. In this embodiment of the invention, when two swirling streams with opposite rotation directions but the same axial movement direction (e.g., both moving forward) meet, the velocity in the central region decreases and the pressure increases, while the rotation of the outer periphery is not completely canceled out. This drives the fluid to form a forward-moving, non-rotating or weakly rotating jet core. At the same time, the shear layer that is not completely canceled out on the periphery will roll up one or more large-scale vortex rings. In this way, the high-temperature airflow in each region from top to bottom inside the furnace body 100 presents different states, achieving full roasting of the droplets.

[0033] In one embodiment, such as Figures 1-3As shown, the outer wall of the furnace body 100 has multiple flow-aiding ports 120 corresponding to the flow-aiding structures 600. Each flow-aiding structure 600 includes a flow-aiding hood 610, a flow-aiding main shaft 620, and flow-aiding blades 630. The flow-aiding hood 610 is installed on the outside of the corresponding flow-aiding port 120 and seals it. The flow-aiding main shaft 620 is rotatably disposed inside the flow-aiding hood 610, with both its upper and lower ends extending to the outside of the flow-aiding hood 610. The flow-aiding blades 630 are fixed to the flow-aiding main shaft 620 and can pass through the flow-aiding ports 120 to enter the interior of the furnace body 100. The outer wall of the furnace body 100 is provided with multiple synchronous connectors, which are connected to the ends of the flow-aiding hoods 610 in each of the multiple flow-aiding structures 600, thus enabling multiple flow-aiding hoods in each group of flow-aiding structures 600 to be connected. The motion transmission between 610 is achieved by connecting one of the flow aid hoods 610 in each group of flow aid structures 600 to a flow aid motor 640. In this embodiment of the invention, among the multiple flow aid structures 600 in the same group, the flow aid motor 640 drives the flow aid main shaft 620 to rotate. The flow aid main shaft 620 drives the flow aid blades 630 to rotate inside the flow aid hood 610. When the flow aid blades 630 rotate into the furnace body 100, they can form an auxiliary airflow along its inner wall inside the furnace body 100. The flow direction of the auxiliary airflow is the same as the direction of the high-temperature vortex formed when the high-temperature gas enters the furnace body 100. Furthermore, under the motion transmission of the synchronous connector, the multiple flow aid main shafts 620 rotate synchronously in the same direction, thus forming auxiliary airflows at different positions, effectively maintaining the intensity and stability of the high-temperature vortex.

[0034] In one embodiment, such as Figures 1-3 As shown, a gear 670 is provided at the end of the flow-aiding main shaft 620. The synchronous connecting member includes a rotating ring 650 and a gear ring portion 660. The rotating ring 650 is located on the outer wall of the furnace body 100 and can rotate around the axis of the furnace body 100. The gear ring portion 660 is fixed on the rotating ring 650 and meshes with multiple gears 670 located in the same group. In this embodiment of the invention, one of the flow-aiding main shafts 620 rotates under the drive of the flow-aiding motor 640, and the gear ring portion 660 achieves synchronous rotation of multiple flow-aiding main shafts 620 by meshing with multiple gears 670, thereby realizing the rotation of the flow-aiding blades 630 in the same group, so as to improve the stability and strength of the high-temperature swirl.

[0035] In one embodiment, such as Figure 1 and Figure 4As shown, a guide cone filter plate 310 is also provided on the inner wall of the furnace cover 300, and an exhaust ring cavity 320 is formed between the guide cone filter plate 310 and the furnace cover 300. The atomizing feed structure 800 is a high-speed centrifugal atomizer, and its lower end atomizing disc passes through the center of the guide cone filter plate 310, extends to the bottom of the guide cone filter plate 310 and contacts its surface; the exhaust gas pipe 700 is connected to the exhaust ring cavity 320 through its outlet connected to the outer wall of the furnace cover 300. In this embodiment of the invention, after the waste acid liquid is atomized by the atomizing feed structure 800, it extends into the furnace body 10. The atomizing disc inside the furnace sprays out the mist, and the moisture on the surface of the formed mist droplets evaporates under the high temperature airflow. The mist then follows the airflow through the guide cone filter plate 310 into the exhaust ring cavity 320, and is then discharged through the exhaust pipe 700. The surface of the guide cone filter plate 310 can filter the solid products that flow with the airflow. The surface of the guide cone filter plate 310 contacts the end of the atomizing feed structure 800 that extends into the furnace body 100. The vibration generated by the atomizing feed structure 800 during operation is transmitted to the guide cone filter plate 310, causing the guide cone filter plate 310 to vibrate and shake off the solid products on its surface, thereby improving the solid-gas separation effect.

[0036] In one embodiment, such as Figure 1 , Figure 2 and Figure 5 As shown, a vibration structure 130 is also provided inside the discharge pipe 110. The vibration structure 130 includes a main vibrating rod 131 and a vibrator 134. The main vibrating rod 131 is arranged along the axial direction of the furnace body 100, and its top extends to the conical bottom area of ​​the furnace body 100. The vibrator 134 is located at the bottom of the flow aid 120 and is connected to the bottom of the main vibrating rod 131. Multiple guide rods 132 are arranged on its outer wall along the axial direction of the main vibrating rod 131, and multiple vibration arcs are arranged on the part of the main vibrating rod 131 located in the conical bottom area of ​​the furnace body 100. The guide rod 132 and the vibrating arc rod 133 are arranged along the conical bottom of the furnace body 100. In this embodiment of the invention, the guide rod 132 and the vibrating arc rod 133 are immersed in the solid product in the conical bottom area of ​​the furnace body 100. The vibrator 134 works and causes the main vibrating rod 131 to vibrate. The vibration is transmitted to multiple guide rods 132 and vibrating arc rods 133. The vibration of the guide rods 132 and the vibrating arc rods 133 will destroy the "bridging" and bulging of high-temperature iron oxide powder in the conical bottom area, promote the rapid sliding of the material and guide it into the furnace bottom discharge structure 400, and promote the furnace bottom discharge.

[0037] In one embodiment, such as Figure 1 , Figure 6 and Figure 7As shown, the furnace bottom discharge structure 400 includes a cylindrical outer shell 410, a feed pipe 420, a circulating cooler 430, and a screw conveyor body 440. A cylindrical inner shell 450 is also provided inside the cylindrical outer shell 410, and a cooling chamber 470 is formed between the inner shell 450 and the outer shell 410. One end of the feed pipe 420 is connected to the discharge pipe 110, and the other end passes through the outer wall of the cylindrical outer shell 410 and the cooling chamber 470, connecting to the interior of the inner shell 450. The screw conveyor body 440 is located inside the inner shell 450 and is used to transport the material introduced by the feed pipe 420 to the subsequent cooling system. The circulating cooler 430 is located outside the cylindrical outer shell 410, and its inlet and outlet are connected by circulating air. Pipes 431 are connected to both ends of the cylindrical outer shell 410 and are connected to the cooling chamber 470. In this embodiment of the invention, the solid material produced after roasting enters the interior of the cylindrical inner shell 450 through the discharge pipe 110 and the feed pipe 420. The screw conveyor body 440 transports the solid material to the cooling system by its own rotation. During the process of transporting the fixed material, the circulating cooler 430 transports the cooling airflow to the cooling chamber 470 through one of the circulating air pipes 431. The cooling airflow exchanges heat between the outer wall of the cylindrical inner shell 450 and the fixed material inside the cylindrical inner shell 450, which can cool the temperature of the cylindrical inner shell 450 and the screw conveyor body 440 to a certain extent, prevent jamming due to thermal expansion, and extend their service life.

[0038] In one embodiment, such as Figure 1 , Figure 6 and Figure 7 As shown, a spiral partition 460 is also provided on the outer wall of the cylindrical inner shell 450. The edge of the spiral partition 460 contacts the inner wall of the cylindrical outer shell 410. The spiral partition 460 divides the cooling chamber 470 into a spiral state along the axis of the cylindrical inner shell 450. In this embodiment of the invention, the spiral state of the cooling chamber 470 can effectively increase the flow time of the cooling airflow inside it, and improve the cooling efficiency of the cylindrical inner shell 450 and the spiral conveying body 440.

[0039] The above embodiment provides a roasting device for the reuse of cold rolling pickling waste liquid, the working principle of which is as follows:

[0040] The waste acid liquid, after being pretreated by a system to remove suspended solids, oil, and mechanical impurities, is pumped to an atomizing feed structure 800 installed on the furnace cover 300. In this embodiment, the atomizing feed structure 800 is a high-speed centrifugal atomizer, whose lower atomizing disc rotates at high speed, tearing the waste acid liquid into extremely fine droplets, which are then sprayed downwards from the top of the furnace body 100.

[0041] Simultaneously, multiple independent combustion chambers of the preheating combustion furnace 500 operate synchronously, generating high-temperature gases. These high-temperature gases are tangentially introduced into the furnace chamber of the furnace body 100 through their respective connected high-temperature gas guide pipes 510. The design of multiple tangential gas inlets enables the high-temperature gases to form a strong and stable high-temperature vortex within the furnace.

[0042] As the waste acid droplets fall downwards, they come into full contact with and mix with the upward-rotating high-temperature vortex. During this stage, two main reactions occur:

[0043] Moisture evaporation: The moisture on the surface of the fog droplets is instantly evaporated by the high-temperature gas.

[0044] Thermal decomposition reaction: Ferrous chloride in the core region of the droplets decomposes at high temperature, producing iron oxide solid particles and hydrogen chloride gas.

[0045] To maintain and enhance the intensity and stability of the high-temperature swirl, multiple sets of flow-aiding structures 600 are installed on the side wall of the furnace body 100. Each set of flow-aiding structures 600 is located at the same height at the inlet of the corresponding high-temperature gas guide pipe 510. The flow-aiding motor 640 drives all the flow-aiding main shafts 620 in the same set to rotate synchronously through a synchronous connector, which in turn drives the flow-aiding blades 630 to rotate. The flow-aiding blades 630 generate an auxiliary airflow in the same direction as the main high-temperature swirl near the furnace inner wall, continuously replenishing energy to the swirl, effectively extending the contact time between the gas and solid phases, ensuring complete droplet roasting, and significantly improving reaction efficiency.

[0046] The iron oxide powder generated by the reaction is a solid particle that gradually settles and accumulates in the cone-shaped bottom area at the bottom of the furnace body 100 under the influence of gravity. To prevent the powder from forming "bridging" or bridging at the bottom of the cone, the vibration structure 130 operates continuously. The vibrator 134 drives the main vibrating rod 131 to vibrate, and transmits the vibration to the material through the guide rod 132 and the vibrating arc rod 133, breaking up the bridging and promoting the smooth discharge of the material through the discharge pipe 110.

[0047] Subsequently, the material enters the cylindrical inner shell 450 of the furnace bottom discharge structure 400 through the feed pipe 420. The screw conveyor body 440 rotates, conveying the high-temperature iron oxide powder to the subsequent cooling system. During this process, the circulating cooler 430 pumps cooling airflow into the cooling chamber 470 between the cylindrical outer shell 410 and the cylindrical inner shell 450. The spiral baffles 460 divide the cooling chamber 470 into spiral channels, extending the cooling airflow path, thereby efficiently cooling the cylindrical inner shell 450 and the screw conveyor body 440, preventing the equipment from jamming due to high-temperature expansion, and extending its service life. Finally, the cooled iron oxide powder becomes the final product.

[0048] The exhaust gas produced by the roasting reaction, mainly composed of water vapor and hydrogen chloride gas, rises to the top of the furnace under the influence of airflow. Inside the furnace cover 300, the exhaust gas first passes through the guide cone filter plate 310. The guide cone filter plate 310 intercepts fine solid particles entrained in the exhaust gas, achieving preliminary solid-gas separation. The intercepted particles are shaken back into the furnace by the vibration generated by the atomizing disc of the high-speed centrifugal atomizer, preventing the filter plate from clogging. The purified exhaust gas enters the exhaust annular cavity 320 formed by the guide cone filter plate 310 and the furnace cover 300, and is finally discharged through the exhaust gas pipe 700 to enter the subsequent exhaust gas purification and treatment system (such as an absorption tower) for recovery or treatment.

[0049] In one optimized embodiment, the swirling streams introduced into adjacent high-temperature gas ducts 510 are designed to rotate in opposite directions. When these two swirling streams with opposite rotational directions but the same axial motion direction meet, a complex flow field is formed in the convergence region, including a core region with reduced velocity and increased pressure, as well as a shear layer that generates large-scale vortex rings. This design results in differentiated airflow patterns at different heights within the furnace body 100, further enhancing the turbulent mixing effect and ensuring that droplets are fully roasted in all areas.

[0050] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not 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 invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

Claims

1. A roasting device for recycling cold rolling pickling waste liquid, comprising a furnace body, an outer frame, a furnace cover, a furnace bottom discharge structure, and a preheating combustion furnace, wherein the furnace body is mounted on the outer frame and its inner wall is lined with refractory material; The furnace cover is located at the top opening of the furnace body. Its outer wall is equipped with an atomizing feed structure and a waste gas pipe for drawing out gaseous products from inside the furnace body. The liquid outlet of the atomizing feed structure extends into the furnace body to atomize and spray waste acid into the furnace. Its distinguishing feature is that… The cone-shaped bottom of the atomizing feed structure is equipped with a discharge pipe, and the discharge pipe is connected to the furnace bottom discharge structure. The furnace body is provided with multiple flow aid structures on its side wall. These multiple flow aid structures are divided into multiple groups on the side wall of the furnace body. The multiple groups are spaced apart along the axial direction of the furnace body, and the flow aid structures in each group are distributed along the circumference of the furnace body, forming a ring array. The preheating combustion furnace is mounted on the outer frame and has multiple independent combustion chambers. Each combustion chamber is connected to a high-temperature gas guide pipe. The end of the high-temperature gas guide pipe away from the preheating combustion furnace is tangentially connected to the side wall of the furnace body, so that the high-temperature gas forms a high-temperature swirling flow inside the furnace body. The connection point between the high-temperature gas guide pipe and the main body of the furnace is at the same height as one of the flow aid structures. Each flow aid structure is configured to provide unidirectional auxiliary airflow to the high-temperature vortex to increase the vortex intensity and stability of the high-temperature vortex when it flows axially.

2. The cold rolling pickling waste liquor recycling roasting apparatus according to claim 1, characterized in that, The high-temperature swirling streams introduced into the main body of the furnace by two adjacent high-temperature gas guide pipes have opposite swirling directions.

3. The cold rolling pickling waste liquor recycling roasting apparatus according to claim 1 or 2, characterized in that, The outer wall of the furnace body is provided with multiple flow aid ports that correspond one-to-one with the flow aid structure. The flow aid structure includes a flow aid hood, a flow aid main shaft, and flow aid blades. The flow aid shroud is installed on the outside of the corresponding flow aid port and is sealed to it. The flow aid main shaft is rotatably located inside the flow aid shroud, with its upper and lower ends extending to the outside of the flow aid shroud. The flow aid blades are fixed on the flow aid main shaft and can pass through the flow aid port into the furnace body. The outer wall of the furnace body is provided with multiple synchronous connectors, which are connected to the ends of the flow aids in multiple flow aid structures to realize the motion transmission between multiple flow aids in each flow aid structure. One of the flow aids in each flow aid structure is connected to a flow aid motor.

4. The cold rolling pickling waste liquor recycling roasting apparatus according to claim 3, characterized in that, The end of the flow-aiding main shaft is provided with a gear, and the synchronous connector includes a rotating ring and a gear ring. The rotating ring is located on the outer wall of the furnace body and can rotate around the axis of the furnace body. The gear ring is fixed on the rotating ring and meshes with multiple gears located in the same group.

5. The cold rolling pickling waste liquor recycling roasting apparatus according to claim 1, characterized in that, The inner wall of the furnace cover is also provided with a flow guide cone filter plate, and an exhaust ring cavity is formed between the flow guide cone filter plate and the furnace cover. The atomizing feeding structure is a high-speed centrifugal atomizer, and the atomizing disc at its lower end passes through the center of the flow guide cone filter plate, extends to the bottom of the flow guide cone filter plate and contacts its surface. The exhaust gas pipe is connected to the outer wall of the furnace cover, and the exhaust gas outlet is connected to the exhaust ring cavity.

6. The cold rolling pickling waste liquor recycling roasting apparatus according to claim 1, characterized in that, The discharge pipe is also equipped with a vibration structure, which includes a vibrating rod and a vibrator. The vibrating main rod is arranged along the axis of the furnace body, and its top extends to the conical bottom area of ​​the furnace body. The vibrator is set at the bottom of the flow aid and connected to the bottom of the vibrating main rod. Multiple guide rods are arranged on its outer wall along the axis of the vibrating main rod, and multiple vibrating arc rods are arranged on the part of the vibrating main rod located in the conical bottom area of ​​the furnace body. The vibrating arc rods are arranged along the conical bottom of the furnace body.

7. The cold rolling pickling waste liquor recycling roasting apparatus according to claim 1, characterized in that, The furnace bottom discharge structure includes a cylindrical outer shell, a feed pipe, a circulating cooler, and a screw conveyor body; The cylindrical outer shell is further provided with a cylindrical inner shell, and a cooling chamber is formed between the cylindrical inner shell and the cylindrical outer shell. One end of the feed pipe is connected to the discharge pipe, and the other end passes through the outer wall of the cylindrical outer shell and the cooling chamber, and is connected to the inside of the cylindrical inner shell. The screw conveyor body is located inside the cylindrical inner shell and is used to transport the material introduced by the feed pipe to the subsequent cooling system. The circulating cooler is located outside the cylindrical outer shell, and its air inlet and outlet are connected to the two ends of the cylindrical outer shell through circulating air pipes and are connected to the cooling chamber.

8. The cold rolling pickling waste liquor recycling roasting apparatus according to claim 7, characterized in that, The outer wall of the cylindrical inner shell is also provided with a spiral partition. The edge of the spiral partition contacts the inner wall of the cylindrical outer shell, and the spiral partition divides the cooling chamber into a spiral state along the axis of the cylindrical inner shell.

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