Pneumatic conveying device for high-temperature, moisture-containing dust

Abstract

The utility model relates to a pneumatic conveying device suitable for high temperature moisture containing dust belongs to metallurgical equipment technical field. Including the intermediate bin for the temporary storage dust removal ash, nitrogen gas delivery and adjusting unit, electric heat tracing unit, ash conveying pipeline, centralized ash bin etc. Nitrogen gas delivery and adjusting unit includes a plurality of pressure reducing valve, pneumatic cut -off valve, links with intermediate bin, ash conveying pipeline through pipeline. Electric heat tracing unit includes heating resistance wire, patch type temperature sensor, temperature control box, and heating resistance wire is wound in the outer surface of intermediate bin and ash conveying pipeline. The utility model adopts the mode of nitrogen gas purging and electric heat tracing in the process of unloading ash, conveying, controls the temperature, humidity of pneumatic conveying device internal environment, avoids the water analysis of the result of temperature reduction in the conveying process, further prevents dust board knot and blocks ash conveying pipeline, influences system operation.

Description

Technical Field

[0001] This utility model belongs to the field of metallurgical equipment technology and relates to a pneumatic conveying device suitable for high-temperature and humid dust. Background Technology

[0002] Pneumatic conveying systems, as core equipment for material handling in the iron and steel metallurgy industry, are widely used in the transfer of materials such as sinter, pellets, and coke due to their advantages of closed conveying, high degree of automation, and adaptability to complex working conditions. However, in hydrogen metallurgy, a new low-carbon metallurgical process, traditional pneumatic conveying technology faces severe challenges. Hydrogen metallurgy employs gas-based vertical shaft furnaces or fluidized bed reduction processes, using hydrogen as the main reducing agent to replace traditional coke. Its core reaction process generates a large amount of high-temperature, dust-laden gas, in which the water vapor volume fraction is much higher than that of traditional blast furnace gas. This unique media characteristic places entirely new demands on pneumatic conveying systems.

[0003] Traditional pneumatic conveying systems are primarily designed for dry materials or low-humidity gas environments. Their working principle involves using high-pressure airflow to suspend and transport materials to the target location. However, this technology has a fundamental flaw in the high-temperature, humid dust conditions generated by hydrogen metallurgy processes: when high-temperature, dust-laden gas enters the conveying pipeline, the gas temperature gradually drops below the dew point due to heat dissipation and gas expansion. During this process, free water and water of crystallization carried in the dust begin to precipitate, forming a viscous mixture with iron oxides, calcium compounds, and other substances in the dust. This mixture exhibits significant changes in rheological properties—it remains a dry powder when the temperature is above a critical value, but its viscosity increases exponentially once the temperature drops below the dew point, eventually forming hard scale at pipe bends, diameter changes, and the inner walls of equipment.

[0004] From the perspective of heat and mass transfer theory, this process involves a complex multiphase flow coupling mechanism: when the high-temperature dust-laden airflow flows inside the pipe, convective heat transfer, radiative heat transfer, and phase change heat transfer occur simultaneously, leading to uneven local temperature field distribution; the liquid film formed by water vapor condensation alters the surface charge distribution of dust particles, enhancing the van der Waals forces between particles; and the growth of the scale layer further deteriorates the flow field distribution, forming a vicious cycle. In actual engineering, this adhesion and blockage phenomenon usually appears after the system has been running for a period of time. In severe cases, it can lead to a reduction in the cross-sectional area of ​​the pipe, forcing the system to shut down for cleaning, directly affecting the continuous and stable operation of the hydrogen metallurgical process.

[0005] Therefore, pneumatic conveying technology currently faces fundamental technical bottlenecks in hydrogen metallurgy scenarios, and there is an urgent need to develop new conveying technology solutions that combine high-temperature adaptability, anti-sticking properties, and efficient heat transfer capabilities. Utility Model Content

[0006] In view of this, the purpose of this utility model is to provide a pneumatic conveying device suitable for high-temperature and humid dust, so as to avoid phenomena such as water separation and dust caking during the conveying process and improve the operational stability of the pneumatic conveying system.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A pneumatic conveying device suitable for high-temperature, humid dust includes a dust collector, an intermediate silo, and a centralized ash silo arranged sequentially. The upper part of the intermediate silo is connected to the dust collector via a first pipe, and a pneumatic feed valve is provided on the first pipe. The bottom of the intermediate silo is connected to the centralized ash silo via an ash conveying pipe. Several first nitrogen ports are also arranged around the wall of the intermediate silo, and a second nitrogen port is provided at the connection between the bottom of the silo and the ash conveying pipe. Heating resistance wires are wound around the outer periphery of the ash conveying pipe and the intermediate silo. The first nitrogen ports, the second nitrogen ports, and the ash conveying pipe are respectively connected to a nitrogen pipe.

[0009] Optionally, the top of the intermediate silo is also directly connected to the centralized ash silo via a second pipe, and the second pipe is equipped with a silo pump exhaust shut-off valve.

[0010] Optionally, a patch temperature sensor is provided on the heating resistance wire, and the patch temperature sensor is electrically connected to the temperature control box.

[0011] Optionally, the first nitrogen port and the second nitrogen port are respectively connected to the nitrogen pipeline through a third pipeline, and the third pipeline is equipped with a pressure reducing valve and a nitrogen shut-off valve.

[0012] Optionally, a pneumatic discharge valve is provided at one end of the ash conveying pipe near the intermediate silo.

[0013] Optionally, the nitrogen pipeline is equipped with a pressure gauge, a pressure reducing valve, and a nitrogen shut-off valve for ash conveying, wherein the nitrogen shut-off valve for ash conveying is located on the nitrogen pipeline near the nitrogen inlet of the ash conveying pipe.

[0014] Optionally, the top of the centralized ash silo is provided with a vent.

[0015] Optionally, a bellows compensator is also provided on the first pipeline, and the bellows compensator is located above the pneumatic feed valve.

[0016] The beneficial effects of this utility model are as follows:

[0017] Pneumatic conveying systems are widely used in the iron and steel metallurgy industry. However, in hydrogen metallurgical processes, the dust-laden gas has a high water content. Using traditional pneumatic conveying methods, the dust temperature gradually decreases during transport, causing water entrained in the dust to precipitate out. The dust easily adheres to the inner walls of pipes and equipment, causing blockages and affecting system operation. This invention relates to a pneumatic conveying device comprising an intermediate silo for temporarily storing dust, a nitrogen conveying and regulating unit, an electric heating unit, ash conveying pipes, and a centralized ash silo. The nitrogen conveying and regulating unit includes several pressure reducing valves and pneumatic shut-off valves, connected to the intermediate silo and ash conveying pipes via pipelines. The electric heating unit includes heating resistance wires, surface-mount temperature sensors, and a temperature control box. The heating resistance wires are wound around the outer surface of the intermediate silo and ash conveying pipes to maintain the temperature of the equipment and pipe inner surfaces within a suitable range, preventing condensation when hot materials contact the inner walls. Before the formal ash conveying, during the ash unloading and conveying process, nitrogen purging and replacement are used to drive the moisture to the centralized ash silo for discharge, thereby avoiding moisture condensation during subsequent ash conveying, reducing the probability of pipeline blockage, and improving the operational stability of the device. Electric heating is used to control the temperature and humidity of the internal environment of the pneumatic conveying system, preventing water precipitation due to temperature drop during conveying, and thus preventing dust from caking and clogging the ash conveying pipeline, which would affect the operation of the system.

[0018] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0020] Figure 1 This is a schematic diagram of the overall device of this utility model.

[0021] Figure label:

[0022] 1. Dust collector; 2. Silo pump exhaust shut-off valve; 3. Corrugated compensator; 4. Intermediate silo; 5. Pressure reducing valve; 6. Nitrogen pipeline; 7. Ash conveying pipeline; 8. Heating resistance wire; 9. Centralized ash silo; 10. Vent; 11. Surface mount temperature sensor; 12. Temperature control box; 13. Pneumatic feed valve; 14. Nitrogen shut-off valve; 15. Pneumatic discharge valve; 16. Pressure gauge; 17. Second nitrogen port; 18. First nitrogen port; 19. Nitrogen port for ash conveying pipe; 20. Nitrogen shut-off valve for ash conveying; 21. First pipeline; 22. Second pipeline; 23. Third pipeline. Detailed Implementation

[0023] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0024] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0025] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and 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, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0026] Please see Figure 1 This is a pneumatic conveying device suitable for high-temperature, moist dust, comprising a dust collector 1, an intermediate silo 4, a nitrogen conveying and regulating unit, an electric heating unit, an ash conveying pipeline 7, and a centralized ash silo 9. The intermediate silo 4 is used to temporarily store dust collected from the dust collector. The nitrogen conveying and regulating unit is used for nitrogen conveying and gas regulation in the pipeline, controlling the nitrogen injection pressure and on / off state at different locations to drive moisture in the space to the centralized ash silo 9. The electric heating unit is installed on the ash conveying pipeline 7 and the intermediate silo 4 for convenient heating and temperature regulation. High-temperature, moist dust is output from the dust collector 1 to the intermediate silo 4, and then enters the centralized ash silo 9 via the nitrogen conveying and regulating unit and the ash conveying pipeline 7. The centralized ash silo 9 has a vent 10 at the top, through which the gas entering the centralized ash silo 9 is finally discharged to the outside.

[0027] The nitrogen delivery and regulation unit includes a first pipeline 21, a second pipeline 22, a third pipeline 23, a nitrogen pipeline 6, and several pressure reducing valves 5 and pneumatic valves. Each pipeline is connected to the intermediate silo 4 and the ash conveying pipeline 7. The electric heating unit includes a heating resistance wire 8, a surface-mount temperature sensor 11, a temperature control box 12, etc.

[0028] Specifically, the pneumatic conveying device of this utility model includes a dust collector 1, an intermediate silo 4, and a centralized ash silo 9 arranged sequentially. The upper part of the intermediate silo 4 is connected to the dust collector 1 through a first pipe 21, and a pneumatic feed valve 13 is provided on the first pipe 21. The bottom of the intermediate silo 4 is connected to the centralized ash silo 9 through an ash conveying pipe 7. Several first nitrogen ports 18 are also arranged around the wall of the intermediate silo 4, through which nitrogen is injected into the intermediate silo 4 from all sides. A second nitrogen port 17 is provided at the connection between the bottom of the silo and the ash conveying pipe 7. The first nitrogen ports 18, the second nitrogen ports 17, and the ash conveying pipe 7 are respectively connected to a nitrogen pipe 6. The first nitrogen ports 18 and the second nitrogen ports 17 are respectively connected to the nitrogen pipe 6 through a third pipe 23, and a pressure reducing valve 5 and a nitrogen shut-off valve 14 are provided on the third pipe 23 to regulate the direct flow of nitrogen into the intermediate silo 4. The first nitrogen ports 18 and the second nitrogen ports 17 are located at different heights of the intermediate silo 4.

[0029] Heating resistance wires 8 are wound at certain intervals around the outer periphery of the ash conveying pipe 7 and the intermediate silo 4. A surface-mount temperature sensor 11 is installed on the heating resistance wire 8 and is electrically connected to the temperature control box 12. The heating resistance wires 8 heat the ash conveying pipe 7 and the intermediate silo 4, maintaining the temperature of the equipment and the inner surface of the pipe within a suitable range. Real-time temperature monitoring is performed by the surface-mount temperature sensor 11, and the real-time temperature is transmitted to the temperature control box 12 for overall heating control.

[0030] A pneumatic discharge valve 15 is provided at one end of the ash conveying pipe 7 near the intermediate silo 4. When the pneumatic discharge valve 15 is opened, the dried dust in the intermediate silo 4 enters the ash conveying pipe 7 from the bottom, and is then transported to the centralized ash silo 9 by pressure-regulated nitrogen. In some embodiments of this utility model, the ash conveying pipe 7 is preferably a seamless steel pipe lined with wear-resistant ceramic or rare earth alloy wear-resistant pipe.

[0031] The nitrogen pipeline 6 is equipped with a pressure gauge 16, a pressure reducing valve 5, and a nitrogen shut-off valve 20 for conveying ash. The nitrogen shut-off valve 20 is located on the nitrogen pipeline 6 near the nitrogen inlet 19 of the ash conveying pipe. The pressure gauge 16 monitors the gas pressure in the nitrogen pipeline 6, and the pressure reducing valve 5 and the nitrogen shut-off valve 20 are used to regulate the nitrogen delivery.

[0032] The top of the intermediate silo 4 is also directly connected to the centralized ash silo 9 via a second pipe 22. The second pipe 22 is equipped with a silo pump exhaust shut-off valve 2. By opening the silo pump exhaust shut-off valve 2 on the second pipe 22 and the nitrogen shut-off valve 14 on the third pipe 23 which is connected to the second nitrogen port 17, and closing the pneumatic discharge valve 15, the intermediate silo 4 can be directly purged.

[0033] A bellows compensator 3 is also installed on the first pipeline 21, located above the pneumatic feed valve 13. The bellows compensator 3 utilizes the effective expansion and contraction of its elastic element to absorb dimensional changes in the first pipeline 21 caused by thermal expansion and contraction, absorbing axial, lateral, and angular displacements. This allows the pipeline to expand and contract freely, significantly reducing or even eliminating thermal stress within the pipeline. The entire system operates under controlled, low-stress conditions, fundamentally ensuring safety.

[0034] In some embodiments of this utility model, the dust collector 1 and the intermediate chamber 4 are provided in several ways, and the ash conveying pipe 7 and the second pipe 22 connected to the several intermediate chambers 4 are respectively connected.

[0035] When using the pneumatic conveying device of this utility model, firstly, the target heating temperature range is set through the temperature control box 12, and the target nitrogen pressure is set by adjusting the pressure reducing valve 5 for the first nitrogen port 18, the second nitrogen port 17, and the nitrogen port 19 of the ash conveying pipe. Once ready, the ash conveying operation can begin.

[0036] Step 1: Open the pneumatic feed valve 13 on the first pipe 21 to discharge the dust in the dust collector 1 to the intermediate chamber 4. After about 40 seconds, close the pneumatic shut-off valve 2 and the pneumatic feed valve 13.

[0037] Step 2: Open nitrogen shut-off valve 14 and silo pump exhaust shut-off valve 2 for about 30 seconds to drive the moisture to the centralized ash silo and then discharge it. Then close silo pump exhaust shut-off valve 2.

[0038] Step 3: Open the pneumatic discharge valve 15 and the nitrogen shut-off valve 20. The dust in the intermediate silo 4 enters the ash conveying pipe 7. Nitrogen enters the ash conveying pipe 7 from the nitrogen pipe 6 and the nitrogen interface 19 of the ash conveying pipe. Under the action of nitrogen, the dust begins to be conveyed to the centralized ash silo 9.

[0039] Step 4: After the ash conveying is completed, close the nitrogen shut-off valve 14, the ash conveying nitrogen shut-off valve 20, and the pneumatic discharge valve 15 to stop the conveying of nitrogen and dust.

[0040] Step 5: Open the silo pump exhaust shut-off valve 2 on the second pipeline 22 and the nitrogen shut-off valve 14 on the third pipeline 23 connected to the second nitrogen port 17 to purge the pipelines. After about 20 seconds, close the valves. One ash conveying process is complete.

[0041] Repeat the above steps to sequentially transport the dust from other dust collectors 1 to the centralized ash silo 9.

[0042] The pneumatic conveying device of this invention temporarily stores dust in the intermediate silo 4. A nitrogen conveying and regulating unit then purges the dust with nitrogen, driving the moisture to the centralized ash silo 9 for discharge. This prevents moisture condensation during subsequent ash conveying, reduces the probability of pipe blockage, and improves the stability of the device's operation. The heating resistance wire 8 of the electric heating unit is wound around the outer surface of the intermediate silo 4 and the ash conveying pipe 7, maintaining the temperature of the equipment and the inner surface of the pipe within a suitable range. This prevents condensation when hot materials contact the inner wall. Furthermore, a patch-type temperature sensor 11 and a temperature control box 12 control the temperature and humidity of the internal environment of the pneumatic conveying device, preventing moisture leaching due to temperature drops during conveying. This, in turn, prevents dust from caking and clogging the ash conveying pipe, thus affecting the overall operation of the device.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A pneumatic conveying device suitable for high-temperature, moist dust, characterized in that: The system includes a dust collector (1), an intermediate silo (4), and a centralized ash silo (9) arranged in sequence. The upper part of the intermediate silo (4) is connected to the dust collector (1) through a first pipe (21), and a pneumatic feed valve (13) is provided on the first pipe (21). The bottom of the intermediate silo (4) is connected to the centralized ash silo (9) through an ash conveying pipe (7). Several first nitrogen ports (18) are also arranged around the wall of the intermediate silo (4), and a second nitrogen port (17) is provided at the connection between the bottom of the silo and the ash conveying pipe (7). Heating resistance wires (8) are wound around the outer periphery of the ash conveying pipe (7) and the intermediate silo (4). The first nitrogen port (18), the second nitrogen port (17), and the ash conveying pipe (7) are respectively connected to the nitrogen pipe (6).

2. The pneumatic conveying device for high-temperature, moist dust as described in claim 1, characterized in that: The top of the intermediate silo (4) is also directly connected to the centralized ash silo (9) through a second pipe (22), and the second pipe (22) is equipped with a silo pump exhaust shut-off valve (2).

3. The pneumatic conveying device for high-temperature, moist dust as described in claim 1, characterized in that: A patch temperature sensor (11) is provided on the heating resistance wire (8), and the patch temperature sensor (11) is electrically connected to the temperature control box (12).

4. The pneumatic conveying device for high-temperature, moist dust as described in claim 1, characterized in that: The first nitrogen port (18) and the second nitrogen port (17) are connected to the nitrogen pipeline (6) through the third pipeline (23), and the third pipeline (23) is equipped with a pressure reducing valve (5) and a nitrogen shut-off valve (14).

5. The pneumatic conveying device for high-temperature, moist dust according to claim 1, characterized in that: The ash conveying pipe (7) is equipped with a pneumatic discharge valve (15) at one end near the intermediate silo (4).

6. The pneumatic conveying device for high-temperature, moist dust according to claim 1, characterized in that: The nitrogen pipeline (6) is equipped with a pressure gauge (16), a pressure reducing valve (5), and a nitrogen shut-off valve (20) for conveying ash. The nitrogen shut-off valve (20) for conveying ash is located on the nitrogen pipeline (6) near the nitrogen inlet (19) of the ash conveying pipe.

7. The pneumatic conveying device for high-temperature, moist dust according to claim 1, characterized in that: The top of the centralized ash silo (9) is provided with a vent (10).

8. The pneumatic conveying device for high-temperature, moist dust according to claim 1, characterized in that: A corrugated compensator (3) is also provided on the first pipeline (21), and the corrugated compensator (3) is located above the pneumatic feed valve (13).

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