Waste heat recycling sludge drying device suitable for iron and steel plant

Abstract

The utility model relates to the technical field of steel plant sludge drying, and discloses a waste heat recycling sludge drying device suitable for a steel plant, which comprises a support, the top of the support is fixedly connected with a storage box, the top of the support is provided with a drying assembly, and the drying assembly comprises a conveying pipe. The bottom of the conveying pipe is fixedly connected to the top of the support, a low-temperature belt type drying machine is arranged on the outer wall of the support, a spiral pipe is rotationally connected into the conveying pipe, and a discharging opening is formed in the bottom of the conveying pipe. In the utility model, sludge is put into the buffer storage bin through a loading vehicle and is conveyed to the low-temperature belt type drying machine through a screw and a scraper blade, hot air of 150 DEG C generated by tail gas of an air cooling section of the annealing furnace is utilized to heat air supplied by a mesh belt to 80 DEG C to dry the sludge, wet and hot air is discharged after being dedusted by the spray tower, and the dried sludge is conveyed through a multi-stage screw; the problems of waste heat waste and high sludge treatment cost are solved, and the energy utilization efficiency and the environmental protection property are improved.

Description

Technical Field

[0001] This utility model relates to the field of sludge drying technology in steel plants, and in particular to a device for drying sludge with waste heat recovery in steel plants. Background Technology

[0002] In the steel industry, the efficient use of energy and the proper disposal of waste have always been the focus of industry attention. When the annealing furnace in a steel plant is running, the temperature of the exhaust gas in the air-cooling section can reach over 150°C. This exhaust gas, which contains a large amount of heat energy, is directly discharged into the atmosphere without being effectively utilized, which not only causes serious energy waste but also causes thermal pollution to the environment. At the same time, during the treatment of acidic wastewater in the pickling line, the neutralization method produces a large amount of sludge with high water content. Even after filtration, the water content of this sludge is still over 50%. Its huge weight and volume bring great difficulties to subsequent disposal. How to combine the abundant waste heat resources of the steel plant with the sludge treatment needs and develop an efficient, energy-saving and environmentally friendly treatment device has become an urgent technical problem to be solved.

[0003] Currently, steel plants generally use gas-fired rotary kilns as the main equipment for sludge drying. The technical principle of gas-fired rotary kilns is to generate high temperatures by burning gas, and then use the high-temperature flue gas to exchange heat with the sludge to evaporate and remove moisture from the sludge. In actual operation, the sludge enters from one end of the rotary kiln. As the kiln rotates, the sludge tumbles continuously inside the cylinder, making full contact with the high-temperature flue gas and gradually completing the drying process. This traditional drying method relies on a large amount of gas consumption, obtaining heat energy by consuming fossil fuels, resulting in high operating costs. Furthermore, its energy utilization method is relatively simple and fails to fully exploit the potential waste heat resources within the steel plant.

[0004] However, existing sludge drying methods have significant drawbacks. On the one hand, a large amount of waste heat from the exhaust gas of the annealing furnace's air-cooling section is wasted, failing to recover and utilize this valuable thermal energy, resulting in energy idleness and loss. On the other hand, sludge drying equipment, mainly based on gas-fired rotary kilns, has long relied on gas as its energy source, which not only significantly increases the production costs of steel plants but also pollutes the environment due to the exhaust emissions from burning gas. This high-energy-consumption, high-cost, and low-resource-utilization sludge drying mode contradicts the development concept of energy conservation, emission reduction, and green production in the steel industry, and urgently requires technological innovation and optimization. Therefore, a waste heat recovery sludge drying device suitable for steel plants is proposed to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a device for drying sludge with waste heat recovery in steel plants, aiming to solve the problems of waste heat and high sludge treatment costs in the prior art.

[0006] The technical solution of this utility model is as follows: a device for drying waste heat recovery sludge in steel plants, including a support frame, a storage box fixedly connected to the top of the support frame, and a drying component provided on the top of the support frame;

[0007] The drying assembly includes a transport pipe, the bottom of which is fixedly connected to the top of the support. A low-temperature belt dryer is installed on the outer wall of the support. A spiral tube is rotatably connected inside the transport pipe. A discharge port is opened at the bottom of the transport pipe. A transport belt is rotatably connected inside the low-temperature belt dryer. The top of the transport belt is located at the bottom of the discharge port. A connecting pipe is fixedly connected to the top of the low-temperature belt dryer. An adjusting component is installed inside the connecting pipe. An induced draft fan is fixedly connected to the top of the low-temperature belt dryer. A discharge pipe is fixedly connected to the other side of the low-temperature belt dryer.

[0008] Optionally, the adjusting component includes a sealing plug, the outer wall of which is slidably connected inside the connecting tube.

[0009] Optionally, an air inlet is provided inside the connecting pipe, and the outer wall of the sealing plug is slidably connected inside the air inlet.

[0010] Optionally, a connecting block is fixedly connected inside the connecting pipe, and a fixed outer shell is fixedly connected to the other side of the connecting block.

[0011] Optionally, the fixed housing has a lifting groove inside, and a connecting column is slidably connected inside the fixed housing.

[0012] Optionally, the bottom of the connecting post is fixedly connected to the top of the sealing plug, and a pressing disc is fixedly connected to the top of the connecting post.

[0013] Optionally, the outer wall of the pressing disc is slidably connected inside the lifting groove, the outer wall of the connecting column is fitted with a spring, the top of the spring is fixedly connected to the bottom of the pressing disc, and the bottom of the spring is fixedly connected to the inner wall of the fixed housing.

[0014] 1. In this utility model, sludge is loaded into a buffer silo by a loading vehicle and then conveyed to a low-temperature belt dryer by a screw conveyor and scraper. The 150°C hot air generated by the exhaust gas of the annealing furnace air-cooling section heats the conveyor belt to 80°C to dry the sludge. The hot and humid air is discharged after being dusted by a spray tower. The dried sludge is conveyed by a multi-stage screw conveyor, which solves the problems of waste heat and high sludge treatment costs, and improves energy utilization efficiency and environmental protection.

[0015] 2. In this utility model, when the generated hot air is transported, its thrust drives the sealing plug to move and compresses the spring. After the transport is completed, the spring rebounds and closes the seal, preventing the hot air from flowing back. This solves the problems of waste heat, high drying energy consumption, and the hidden danger of hot air backflow, and improves energy utilization, drying stability, and system safety.

[0016] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0017] Figure 1 This is a three-dimensional schematic diagram of a waste heat recovery sludge drying device suitable for steel plants, as proposed in this utility model.

[0018] Figure 2 This utility model presents a schematic diagram of a low-temperature belt dryer for drying sludge using waste heat recovery in steel plants.

[0019] Figure 3 This is a schematic diagram of the internal structure of the transport pipe of a waste heat recovery sludge drying device for steel plants, as proposed in this utility model.

[0020] Figure 4 This utility model presents a schematic diagram of the internal structure of the connecting pipe of a waste heat recovery sludge drying device suitable for steel plants.

[0021] Figure 5 This is a schematic diagram of the internal structure of the fixed outer shell of a waste heat recovery sludge drying device for steel plants, as proposed in this utility model.

[0022] The names and numbers of the components in the diagram are as follows:

[0023] 1. Support frame; 2. Low-temperature belt dryer; 3. Discharge pipe; 4. Exhaust fan; 5. Connecting pipe; 6. Conveyor belt; 7. Storage box; 8. Conveyor pipe; 9. Spiral pipe; 10. Discharge port; 11. Sealing plug; 12. Connecting block; 13. Fixed outer shell; 14. Connecting column; 15. Pressing disc; 16. Spring; 17. Lifting groove; 18. Air inlet. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0025] Reference Figures 1-3This utility model provides an embodiment of a device for drying waste heat recovery sludge in steel plants, comprising a support 1, which is welded from high-strength steel and has anti-slip and shock-absorbing pads at the bottom, which not only enhances the overall stability of the device but also reduces vibration and noise during operation. A storage box 7 is fixedly connected to the top of the support 1. The storage box 7 is a rectangular box structure made of double-layer stainless steel. The inner layer has good corrosion resistance and can effectively resist the erosion of acidic substances in the sludge; the outer layer is provided with a heat insulation layer to prevent the sludge from changing its properties due to temperature changes during storage. A drying component is provided on the top of the support 1.

[0026] The drying assembly includes a transport pipe 8, the bottom of which is fixedly connected to the top of a support 1. A low-temperature belt dryer 2 is installed on the outer wall of the support 1. The low-temperature belt dryer 2 is an existing mature piece of equipment, typically consisting of a housing, heating system, and mesh belt drive system, used for drying sludge. Further details are omitted here. A spiral tube 9 is rotatably connected inside the transport pipe 8. The spiral tube 9 consists of spiral blades and a central shaft. The spiral blades are made of high-hardness manganese steel, and the central shaft is made of high-quality carbon structural steel. The two are tightly joined by welding. The spiral tube 9 is driven by a motor, which transports the sludge in the storage box 7 along the transport pipe 8 to a designated location. An opening is located at the bottom of the transport pipe 8. The low-temperature belt dryer 2 has a discharge port 10, the size of which is designed according to the width of the conveyor belt 6 to ensure that the sludge can be smoothly discharged onto the conveyor belt 6. The conveyor belt 6 is rotatably connected inside the low-temperature belt dryer 2, and the top of the conveyor belt 6 is located at the bottom of the discharge port 10. A connecting pipe 5 is fixedly connected to the top of the low-temperature belt dryer 2, and an adjustment component is installed inside the connecting pipe 5. An induced draft fan 4 is fixedly connected to the top of the low-temperature belt dryer 2. The induced draft fan 4 is an axial flow fan, model T35-11, with a power of 5.5kW, used to extract the hot and humid air generated during the drying process and transport it to the spray tower for dust removal. A discharge pipe 3 is fixedly connected to the other side of the low-temperature belt dryer 2.

[0027] Specifically, in the steel plant's production process, the pickling line generates a large amount of acidic wastewater, which is usually treated by neutralization. After the neutralization reaction, a large amount of sludge is generated. This sludge can be temporarily stored in the storage box 7. The storage box 7 has a large volume and good sealing performance, which can effectively prevent the sludge from spreading odors and causing secondary pollution during storage. When the sludge needs to be treated, the spiral pipe 9 is started. With its unique spiral blade structure, the spiral pipe 9, driven by a motor, can stably transport the sludge inside the storage box 7 along the transport pipe 8. The sludge is continuously pushed in the transport pipe 8 until it reaches the discharge port 10 and is discharged from the discharge port 10 to the top of the conveyor belt 6. The conveyor belt 6 is made of high-strength, corrosion-resistant material and runs at a constant speed, smoothly transporting the sludge into the low-temperature belt dryer 2. At the same time, the exhaust gas generated by the steel plant's annealing furnace becomes a key heat source. The annealing furnace exhaust gas is connected to the connecting pipe 5. The exhaust gas, with a temperature exceeding 150°C, is introduced into the low-temperature belt dryer 2. Inside the dryer, the exhaust gas heats the conveyor belt air temperature to 80°C. At this temperature, the hot air comes into full contact with the wet sludge on the conveyor belt, exchanging heat and moisture. Through continuous heat transfer, the moisture in the sludge evaporates, eventually reducing the moisture content to 20%. The humid and hot air generated during the drying process (48-65°C) is transported to the spray tower for dust removal by the induced draft fan 4. The spray system in the spray tower sprays out fine water mist, which comes into full contact with the humid and hot air, effectively adsorbing the dust and harmful substances. The purified air meets environmental emission standards before being discharged. The dried sludge is then smoothly transported to the sludge disposal point through the discharge pipe 3 for subsequent resource utilization or disposal. This not only reduces the pollution of the environment caused by exhaust gas emissions but also realizes the recycling of waste heat, significantly reducing energy consumption and achieving a win-win effect of energy conservation, emission reduction, and economic and environmental protection.

[0028] Reference Figure 1 , Figure 4 and Figure 5The adjustment component includes a sealing plug 11, which is a conical structure made of high-temperature and oxidation-resistant material. Its outer wall is finely polished and fits tightly against the inner wall of the connecting pipe 5 to seal the air inlet 18 and prevent hot air backflow. The outer wall of the sealing plug 11 is slidably connected to the inside of the connecting pipe 5, which has an air inlet 18. A connecting block 12 is fixedly connected inside the connecting pipe 5, and a fixed outer shell 13 is fixedly connected to the other side of the connecting block 12. A lifting groove 17, a cylindrical groove, is provided inside the fixed outer shell 13 for connecting the connecting column 14 and the pressing circle. The sliding of the disc 15 provides a guiding space. A connecting post 14 is slidably connected inside the fixed housing 13. The bottom of the connecting post 14 is fixedly connected to the top of the sealing plug 11. A pressing disc 15 is fixedly connected to the top of the connecting post 14. The pressing disc 15 is a circular disc structure with a diameter larger than that of the connecting post 14. Its outer wall is slidably engaged with the inner wall of the lifting groove 17 to transmit the elastic force of the spring 16 and limit the sliding stroke of the connecting post 14. The outer wall of the pressing disc 15 is slidably connected inside the lifting groove 17. A spring 16 is sleeved on the outer wall of the connecting post 14. The top of the spring 16 is fixedly connected to the bottom of the pressing disc 15, and the bottom of the spring 16 is fixedly connected to the inner wall of the fixed housing 13.

[0029] Specifically, in the tail gas transportation process of the annealing furnace in the steel plant, when the tail gas begins to be transported, the thrust generated by it acts on the sealing plug 11, causing the sealing plug 11 to move downward. The top of the sealing plug 11 is connected to the connecting column 14. As the sealing plug 11 moves, the connecting column 14 slides inside the fixed housing 13, thereby pushing the pressing disc 15 inside the fixed housing 13 to slide downward in the lifting groove 17. The sliding of the pressing disc 15 compresses the spring 16, and at the same time opens the air inlet 18, allowing the high-temperature tail gas to smoothly enter the dryer to participate in sludge drying. When the tail gas transportation ends and the thrust is lost, the compressed spring 16 rebounds with its elastic potential energy, causing the pressing disc 15 to move upward in the lifting groove 17. Through the connecting column 14, the sealing plug 11 is pulled back to its original position, tightly closing the air inlet 18, effectively preventing hot gas backflow, ensuring the stability of the drying process, and improving the efficiency of waste heat utilization.

[0030] Working Principle: Steel plant pickling lines generate a large amount of acidic wastewater that requires treatment. This wastewater is typically neutralized, resulting in a large amount of sludge. This sludge is transported to a storage box 7 for storage. When further treatment is needed, the spiral pipe 9 is activated, moving the sludge from the storage box 7 through the transport pipe 8 to the discharge port 10, where it is discharged onto the top of the conveyor belt 6. The conveyor belt 6 then transports the sludge to the low-temperature belt dryer 2. Simultaneously, during transport, annealing furnace exhaust gas is transported through the connecting pipe 5 and discharged into the low-temperature belt dryer 2. This heats the conveyor belt air to 80°C, exchanging heat and moisture with the wet sludge on the belt, reducing the sludge's moisture content to 20%. The resulting 48-65°C humid air is then transported by the induced draft fan 4 to a spray tower for dust removal before being discharged. The dried sludge is then transported through the discharge pipe 3 to the sludge disposal point, thus reducing environmental pollution from exhaust emissions. The recycling of waste heat also reduces energy consumption.

[0031] Furthermore, during exhaust gas transportation, the thrust drives the sealing plug 11 to move, and then the sealing plug 11 drives the top connecting column 14 to slide. Then, the connecting column 14 drives the pressing disc 15 inside the fixed housing 13 to slide inside the lifting groove 17, thereby compressing the spring 16 and opening the air inlet 18 to transport the exhaust gas. After the transportation is completed, the spring 16 rebounds and drives the pressing disc 15 back to its original position, thereby driving the sealing plug 11 to slide back to its original position and closing the air inlet 18 to prevent hot gas backflow.

[0032] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0033] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

[0034] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A device for drying sludge with waste heat recovery in steel plants, comprising a support frame (1), characterized in that: A storage box (7) is fixedly connected to the top of the bracket (1), and a drying component is provided on the top of the bracket (1); The drying assembly includes a transport pipe (8), the bottom of which is fixedly connected to the top of the support (1). A low-temperature belt dryer (2) is provided on the outer wall of the support (1). A spiral pipe (9) is rotatably connected inside the transport pipe (8). A discharge port (10) is provided at the bottom of the transport pipe (8). A transport belt (6) is rotatably connected inside the low-temperature belt dryer (2). The top of the transport belt (6) is located at the bottom of the discharge port (10). A connecting pipe (5) is fixedly connected to the top of the low-temperature belt dryer (2). An adjusting component is provided inside the connecting pipe (5). An induced draft fan (4) is fixedly connected to the top of the low-temperature belt dryer (2). A discharge pipe (3) is fixedly connected to the other side of the low-temperature belt dryer (2).

2. The apparatus for drying waste heat recovery sludge in steel plants according to claim 1, characterized in that: The adjustment assembly includes a sealing plug (11), the outer wall of which is slidably connected inside the connecting tube (5).

3. The apparatus for drying waste heat recovery sludge in steel plants according to claim 2, characterized in that: An air inlet (18) is provided inside the connecting pipe (5), and the outer wall of the sealing plug (11) is slidably connected to the air inlet (18).

4. The apparatus for drying waste heat recovery sludge in steel plants according to claim 3, characterized in that: A connecting block (12) is fixedly connected inside the connecting pipe (5), and a fixed outer shell (13) is fixedly connected to the other side of the connecting block (12).

5. The apparatus for drying waste heat recovery sludge in steel plants according to claim 4, characterized in that: The fixed outer shell (13) has a lifting groove (17) inside, and a connecting column (14) is slidably connected inside the fixed outer shell (13).

6. The apparatus for drying waste heat recovery sludge in steel plants according to claim 5, characterized in that: The bottom of the connecting post (14) is fixedly connected to the top of the sealing plug (11), and a pressing disc (15) is fixedly connected to the top of the connecting post (14).

7. The apparatus for drying waste heat recovery sludge in steel plants according to claim 6, characterized in that: The outer wall of the pressing disc (15) is slidably connected to the inside of the lifting groove (17), and the outer wall of the connecting column (14) is fitted with a spring (16). The top of the spring (16) is fixedly connected to the bottom of the pressing disc (15), and the bottom of the spring (16) is fixedly connected to the inner wall of the fixed outer shell (13).

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