A cold extraction flue waste heat utilization system

Abstract

This utility model discloses a cold-extraction flue waste heat utilization system, which includes multiple raw material bins that are transported to a sintering machine via a mixer. The flue gas generated during sintering is discharged through a flue. A waste heat boiler is installed on the flue, and the steam generated by the waste heat boiler is transported through a steam pipe to the mixer and the uniform heating components in the raw material bins to preheat the materials as a whole. This utility model provides a cold-extraction flue waste heat utilization system and its preheating device. By recovering the waste heat of the flue gas through the waste heat boiler to generate steam, and then transporting the steam to the mixer and the raw material bins to preheat the materials, it not only realizes the effective utilization of the waste heat of the flue gas, but also increases the initial temperature of the materials. It has the advantages of reducing the energy consumption of the sintering machine, improving sintering efficiency and quality stability.

Description

Technical Field

[0001] This utility model relates to the field of flue waste heat utilization, specifically to a cold-extraction flue waste heat utilization system. Background Technology

[0002] In the metallurgical industry, the sintering workshop plays a crucial role in preparing sintered materials from various raw materials. These raw materials include concentrates, mineral powders, fuels, fluxes, recycled ore, and iron-containing production waste, requiring precise batching, thorough mixing, and granulation to obtain sintered materials that meet process requirements. In traditional processes, various raw materials are conveyed to a mixer via a raw material silo feeding system, mixed in a drum agitator, and then conveyed to a sintering machine for high-temperature sintering (e.g., sintering). Figure 2 (As shown). However, this process has two significant technical drawbacks: firstly, the high-temperature flue gas generated during sintering is directly discharged from the chimney after dust removal through the flue system. This flue gas carries a large amount of heat energy, resulting in severe heat loss; secondly, the initial temperature of the mixture entering the sintering machine is generally low, which not only increases the heat energy consumption of the sintering machine but also directly affects the efficiency and quality stability of the sintering process. Existing technologies lack effective system solutions to simultaneously address the two interrelated technical challenges of flue gas waste heat recovery and material preheating. Therefore, existing technologies urgently need improvement to address these issues. Utility Model Content

[0003] To address the aforementioned problems, this utility model provides a waste heat utilization system for cold-extraction flues.

[0004] This utility model is achieved through the following technical solution:

[0005] A waste heat utilization system for cold extraction flue includes multiple raw material bins that are transported to a sintering machine via a mixer. The flue gas generated during sintering is discharged through a flue. A waste heat boiler is installed on the flue. The steam generated by the waste heat boiler is transported through a steam pipe to the mixer and a uniform heating component in the raw material bins to preheat the materials as a whole.

[0006] Alternatively, steam generated by the waste heat boiler can be transported through steam pipes to the mixing heating pipes to preheat the materials inside the mixer.

[0007] Alternatively, the steam pipe can be connected to a uniform heating assembly in the corresponding raw material silo via multiple heating branches.

[0008] Further optionally, the uniform heating component includes a heating jacket disposed outside the raw material silo, and a number of vertical heat-conducting pipes uniformly disposed inside the raw material silo and communicating downward with the heating jacket.

[0009] Alternatively, a guide pipe is provided at the bottom of the heating jacket, and a control valve is installed on the guide pipe.

[0010] Compared with existing technologies, the beneficial effects of this utility model are as follows: This utility model provides a cold-extraction flue waste heat utilization system and its preheating device, which recovers flue waste heat through a waste heat boiler to generate steam, and delivers the steam to the mixer and raw material silo to preheat the materials. This not only realizes the effective utilization of flue gas waste heat, but also increases the initial temperature of the materials, and has the advantages of reducing sintering machine energy consumption, improving sintering efficiency and quality stability. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the system of this utility model;

[0012] Figure 2 This is a schematic diagram of the prior art of this utility model;

[0013] In the diagram: 1. Raw material silo; 2. Mixer; 3. Sintering machine; 4. Flue; 5. Waste heat boiler; 6. Steam pipe; 7. Mixing heating pipe; 8. Heating branch pipe; 9. Heating jacket; 10. Heat conduction pipe; 11. Guide pipe. Detailed Implementation

[0014] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments:

[0015] like Figure 1 As shown, a cold-extraction flue waste heat utilization system includes multiple raw material bins that are transported to a sintering machine via a mixer. The flue gas generated during sintering is discharged through a flue. A waste heat boiler is installed on the flue. The steam generated by the waste heat boiler is transported through a steam pipe to the mixer and a uniform heating component in the raw material bins to preheat the materials as a whole.

[0016] The raw material silo stores various raw materials required for sintering, including concentrates, mineral powders, and fuels. The mixer uses a drum-type structure, achieving uniform mixing of materials through rotational motion. The sintering machine is either a belt sintering machine or a ring sintering machine, used for high-temperature sintering of the mixture. The flue is made of high-temperature resistant material and connects the sintering machine to the dust removal system. The waste heat boiler is a flue-type or water-tube boiler, installed in the middle section of the flue. The steam pipes are made of insulated steel pipes, divided into main pipes and branch pipes. The main pipe connects to the waste heat boiler, and the branch pipes lead to the mixer and the raw material silo, respectively. The uniform heating assembly includes a heating jacket installed on the outer wall of the raw material silo and uniformly distributed heat-conducting pipes inside. The heat-conducting pipes are connected to the heating jacket to form a circulating heating system.

[0017] This system generates steam by recovering waste heat from sintering flue gas, and then uses this steam to preheat the raw materials. Specifically, high-temperature flue gas heats water in a waste heat boiler to produce steam, which is then piped to the heating components of the mixer and raw material silo. In the mixer, the steam heats the materials during the mixing process through built-in heating pipes; in the raw material silo, the steam uniformly preheats the stored raw materials through a heating jacket and heat-conducting pipes. This achieves effective utilization of waste heat from the flue gas and simultaneously increases the temperature of the materials entering the sintering machine. Compared with existing technologies, this solution not only reduces heat loss caused by direct flue gas emissions but also improves sintering efficiency by preheating the materials, solving the problem of excessively low mixed material temperature affecting sintering quality.

[0018] Furthermore, this application also proposes that steam generated by the waste heat boiler is transported through a steam pipe to the mixing heating pipe to preheat the materials inside the mixer.

[0019] The steam pipe can be made of seamless stainless steel, with an outer diameter preferably ranging from 50-200 mm and a wall thickness of 3-8 mm. The steam pipe and the mixing heating pipe are connected by flanges, and graphite gaskets are installed between the flanges for sealing.

[0020] Specifically, this technical solution involves installing a mixing heating tube inside the mixer, utilizing steam generated by a waste heat boiler to directly heat the materials. The steam is delivered to the mixing heating tube through a steam pipe, achieving uniform preheating of the materials during the mixing process. This increases the temperature of the mixture, solving the problem of excessively low temperature of the mixture entering the sintering machine. Compared to existing technologies, this solution achieves efficient utilization of waste heat, improves heat exchange efficiency, and avoids additional energy consumption.

[0021] Furthermore, this application also proposes that the steam pipe is connected to the uniform heating component of the corresponding raw material silo via multiple heating branch pipes.

[0022] Specifically, the heating branch pipes, as key components for steam distribution, can be implemented in the following ways: flexible connections are achieved using stainless steel corrugated pipes, with the pipe diameter set to DN25-DN50 according to the heat load requirements of the raw material silo; a flow regulating valve is installed at the inlet end of each branch pipe, and the outlet end is connected to the heating assembly through a flange; 3-6 connection points are evenly distributed along the circumference of the raw material silo in the branch pipes, and the spacing between the branch pipes is maintained at 1.2-1.5 meters to ensure the uniformity of the heat field.

[0023] This technical solution utilizes a tiered steam delivery structure to distribute high-temperature steam generated by a waste heat boiler to the independent heating units of each raw material silo via a main pipeline. The multi-branch pipe design effectively solves the temperature gradient problem within the silo caused by traditional single-point steam supply, ensuring uniform preheating of the materials before delivery. Compared to existing technologies, this structure avoids heat loss during long-distance steam transport and, through modular branch pipe arrangement, meets the differentiated temperature control requirements of different raw material silos, significantly improving the temperature stability of raw materials during the mixing process.

[0024] Furthermore, this application also proposes that the uniform heating assembly includes a heating jacket disposed outside the raw material silo, and a plurality of vertical heat-conducting pipes uniformly disposed inside the raw material silo and communicating downward with the heating jacket. A guide pipe is provided at the bottom of the heating jacket, and a control valve is installed on the guide pipe.

[0025] Specifically, the heating jacket is a closed cavity structure surrounding the outer wall of the raw material silo, and can be made of stainless steel or carbon steel. Heat-conducting pipes are vertically distributed in an array inside the raw material silo, with their lower ends sealed to the heating jacket via flanges or welding. The guide pipes are preferably DN50-DN80 pipes, and the control valves can be manual gate valves or electric regulating valves. As a preferred embodiment, spiral guide vanes can be installed on the inner wall of the heat-conducting pipes to enhance heat exchange efficiency. Furthermore, an exhaust valve can be added to the top of the heating jacket to remove accumulated water formed by steam condensation.

[0026] Therefore, this technical solution achieves uniform heat transfer from the outer wall of the raw material silo to the internal material through a combination of a heating jacket and heat-conducting pipes. After the steam enters the heating jacket, the heat is radiated to the material inside the silo through the heat-conducting pipe walls, while condensate is discharged centrally through a guide pipe. Compared with traditional single-layer silo wall heating methods, this structure effectively solves the problem of uneven heating in the central area of ​​the raw material silo, enabling the material to reach a stable preheating temperature overall. The control valve facilitates the adjustment of the condensate discharge rate, thereby precisely controlling the steam pressure and heat exchange intensity within the heating jacket.

[0027] Furthermore, this application also proposes that a guide pipe is provided at the bottom of the heating jacket, and a control valve is installed on the guide pipe.

[0028] Specifically, a guide pipe is located at the bottom of the heating jacket to discharge condensate or incompletely evaporated steam from the system. The control valve can be a manual valve or an automatic control valve; the automatic control valve is preferably an electric or pneumatic regulating valve. As a preferred embodiment, the guide pipe can be configured as a downward-sloping pipe with an inclination angle of 15-30 degrees to facilitate smooth condensate drainage. Furthermore, the end of the guide pipe can be connected to a condensate recovery system to achieve water resource recycling. The control valve can be equipped with a temperature sensor, which automatically opens to discharge condensate when the temperature inside the heating jacket is detected to be below a set value.

[0029] Therefore, this technical solution effectively solves the problem of condensate accumulation at the bottom of the heating jacket through the cooperation of the guide pipe and the control valve. The guide pipe ensures timely drainage of condensate, preventing it from affecting the heating effect; the control valve enables precise control of the drainage process. Compared with existing technologies, this solution significantly improves the stability and thermal efficiency of the heating system, while avoiding pipe corrosion caused by condensate accumulation. Specifically, when steam condenses in the heating jacket and heat pipes, the condensate collects at the bottom under gravity and is discharged from the system through the guide pipe. The control valve can adjust the drainage volume according to actual needs, ensuring the system is always in optimal operating condition.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A waste heat recovery system for cold-extraction flues, comprising multiple raw material bins (1) which are fed to a sintering machine (3) via a mixer (2) for sintering, and the flue gas generated during sintering is discharged through a flue (4), characterized in that: A waste heat boiler (5) is installed on the flue (4). The steam generated by the waste heat boiler (5) is transported through a steam pipe to the mixer (2) and the uniform heating components in the raw material silo (1) to preheat the material as a whole.

2. The waste heat recovery system for cold-extraction flues according to claim 1, characterized in that: The steam generated by the waste heat boiler (5) is transported through the steam pipe (6) to the mixing heating pipe (7) to preheat the material inside the mixer (2).

3. The waste heat recovery system for cold-extraction flues according to claim 2, characterized in that: The steam pipe (6) is connected to the uniform heating component of the corresponding raw material silo (1) through multiple heating branch pipes (8).

4. The waste heat recovery system for cold-extraction flues according to claim 1, characterized in that: The uniform heating assembly includes a heating jacket (9) disposed outside the raw material silo (1), and a plurality of vertical heat-conducting pipes (10) are uniformly disposed inside the raw material silo (1) and communicate downward with the heating jacket (9).

5. The waste heat recovery system for cold-extraction flues according to claim 4, characterized in that: The bottom of the heating jacket (9) is provided with a guide pipe (11), and a control valve is installed on the guide pipe (11).

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