Pulverized coal burner suitable for drying roller of asphalt mixing plant

Abstract

The utility model discloses a pulverized coal burner suitable for a drying roller of an asphalt mixing plant, belongs to the technical field of burners, and aims to overcome the defect of high cost of the conventional pulverized coal burner. The combustor comprises a fan, a combustion head and a ventilation pipe, the combustion head is provided with a combustion cavity, a flow guide disc is arranged in the combustion head, an outer channel and an inner channel which are separated from each other are arranged on the flow guide disc, a pulverized coal channel is arranged on the combustor and communicated with the inner channel, the ventilation pipe is communicated with the outer channel, and an inclined first flow guide piece is arranged on the outer channel. An inclined second flow deflector is arranged on the inner channel, and the inclined directions of the first flow deflector and the second flow deflector are opposite, so that the rotating directions of pulverized coal and air are opposite after the pulverized coal and the air pass through the flow guide disc. The combustor directly combusts the pulverized coal, the equipment cost is reduced, air and the pulverized coal are mixed more sufficiently through reverse rotational flow, and the pulverized coal is combusted more sufficiently.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of combustor, and relates to a pulverized coal combustor suitable for bitumen mixing station drying cylinder. BACKGROUND

[0002] The existing combustor usually needs to convert pulverized coal into coal gas through a gasification furnace, and then burns the coal gas mixed with air to ensure that the pulverized coal can be fully burned to heat the bitumen, stone and other paving materials. Such a pulverized coal combustor device is relatively large and high in cost, but if the pulverized coal is directly burned, the phenomenon of insufficient combustion of the pulverized coal in the existing combustor is relatively serious, which will cause a large waste of the pulverized coal. SUMMARY

[0003] The utility model discloses a pulverized coal combustor suitable for bitumen mixing station drying cylinder in view of the problems existing in the prior art, which aims at overcoming the defect that the existing pulverized coal combustor is high in cost.

[0004] The utility model is realized as follows:

[0005] A pulverized coal combustor suitable for bitumen mixing station drying cylinder, comprising a fan, a combustion head and a ventilation pipe connected between the fan and the combustion head, wherein the combustion head has a combustion cavity, characterized in that a flow guide disc is arranged in the combustion head, the flow guide disc is provided with an outer passage and an inner passage which are separated from each other, a pulverized coal passage of the combustor is in communication with the inner passage, the ventilation pipe is in communication with the outer passage, an inclined first flow guide piece is arranged on the outer passage, an inclined second flow guide piece is arranged on the inner passage, and the inclined directions of the first flow guide piece and the second flow guide piece are opposite to each other, so that the rotating directions of the pulverized coal and the air are opposite after passing through the flow guide disc.

[0006] The flow guide disc with the outer passage and the inner passage is arranged in the combustion head, the outer passage is provided with the inclined first flow guide piece, the inner passage is provided with the inclined second flow guide piece, and the inclined directions of the first flow guide piece and the second flow guide piece are opposite. When the air enters the outer passage through the ventilation pipe, the first flow guide piece will make the air produce a rotating motion. At the same time, the pulverized coal enters the inner passage through the pulverized coal passage, and the second flow guide piece makes the pulverized coal also produce a rotating motion, and the rotating directions of the pulverized coal and the air are opposite. In this way, the pulverized coal and the air can impact and mix with each other in opposite rotating directions after leaving the flow guide disc. The relative speed and the contact area between the air flow and the pulverized coal flow are increased by using the opposite rotating air flow and the pulverized coal flow. In the rotating process, the pulverized coal particles and the air can be more fully contacted and collided, the conventional laminar flow state is broken, the pulverized coal and the air can be more uniformly and rapidly mixed together, and good conditions are created for subsequent full combustion.

[0007] Compared with the existing combustor which needs to convert the coal powder into coal gas through a gasifier and then combust, the coal powder combustor of the improved scheme has a relatively simple structure and does not need large auxiliary equipment such as a gasifier, thereby reducing the equipment cost and operation cost and overcoming the defect of high cost of the existing coal powder combustor.

[0008] Preferably, the center of the flow guide disc is provided with a center passage, the combustor is provided with a fuel oil passage in communication with the center passage, and the fuel oil passage is provided with a fuel oil gun.

[0009] The combustion head is provided with a spacer sleeve shorter than the combustion head, and the spacer sleeve and the inner wall of the combustion head have a cooling passage. The air in the combustion air passage is partially branched to the cooling passage, and the cooling passage effectively takes away the high-temperature heat generated by combustion, prevents the combustion head from deforming and damaging due to overheating, and protects the key components of the combustor.

[0010] Preferably, the combustion air passage between the fan and the flow guide disc is provided with an ignition assembly.

[0011] Preferably, the ignition assembly is a liquefied gas tertiary ignition assembly.

[0012] Preferably, the inner wall of the ventilation pipe is provided with a fixing seat, the fixing rod is adjustably arranged on the fixing seat, and the flow guide disc is fixed on the fixing rod.

[0013] Preferably, the ventilation pipe is provided with an access hole, the access hole is provided with a door body, the door body is provided with an observation hole, and the observation hole is provided with a transparent piece.

[0014] Preferably, the burner comprises a pulverized coal inlet pipe, the pulverized coal inlet pipe is vertically arranged and connected to the pulverized coal channel, and the pulverized coal inlet pipe deviates from the center position of the lower end of the pulverized coal channel.

[0015] The burner directly burns the pulverized coal, reduces the equipment cost, and makes the two mixtures more fully through the reverse rotation flow of air and the pulverized coal, so that the combustion of the pulverized coal is more sufficient. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 FIG. 4 is a sectional view of the burner;

[0017] Figure 2 FIG. 6 is a structural schematic view of the flow guide disc.

[0018] FIG. 1 is a structural schematic view of the burner; DETAILED DESCRIPTION

[0019] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, so as to make the technical solution of this utility model easier to understand and master. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0020] This embodiment provides a pulverized coal burner suitable for the drying drum of an asphalt mixing plant, such as... Figure 1 , 2 As shown, the device includes a fan 100, a burner head 200, and a ventilation pipe 300 connecting the fan 100 and the burner head 200. The burner head 200 has a combustion chamber and a guide plate 400 is installed inside the burner head 200. The guide plate 400 is provided with an outer channel 410 and an inner channel 420 that are separated from each other. The burner is provided with a pulverized coal channel that communicates with the inner channel 420. The ventilation pipe 300 communicates with the outer channel 410. An inclined first guide vane 411 is provided on the outer channel 410, and an inclined second guide vane 421 is provided on the inner channel 420. The first guide vane 411 and the second guide vane 421 are inclined in opposite directions so that the pulverized coal and air rotate in opposite directions after passing through the guide plate 400.

[0021] A guide plate 400 with an outer channel 410 and an inner channel 420 is provided inside the burner head 200. The outer channel 410 is equipped with an inclined first guide vane 411, and the inner channel 420 is equipped with an inclined second guide vane 421, with the two inclined directions being opposite. When air enters the outer channel 410 through the ventilation pipe 300, the first guide vane 411 causes the air to rotate; simultaneously, pulverized coal enters the inner channel 420 through the pulverized coal channel, and the second guide vane 421 also causes the pulverized coal to rotate, but in the opposite direction to the rotation of the air. This allows the pulverized coal and air to collide and mix with each other in opposite directions of rotation after leaving the guide plate 400. Utilizing the opposing rotating airflow and pulverized coal flow increases the relative velocity and contact area between the two. During the rotation process, the pulverized coal particles can come into more full contact and collide with the air, breaking the conventional laminar flow state, allowing the pulverized coal and air to mix more evenly and rapidly, creating favorable conditions for subsequent complete combustion.

[0022] Compared to existing burners that require a gasifier to convert pulverized coal into gas before combustion, this improved pulverized coal burner has a simpler structure and does not require large auxiliary equipment such as a gasifier, thus reducing equipment and operating costs and overcoming the high cost of existing pulverized coal burners. The thorough mixing of pulverized coal and air allows for more complete combustion of the pulverized coal within the combustion chamber, reducing incomplete combustion, improving combustion efficiency, and consequently increasing thermal energy utilization. This means that while providing the same amount of heat to the drying drum of an asphalt mixing plant, the amount of pulverized coal used can be reduced, decreasing waste, improving energy efficiency, and lowering production costs.

[0023] like Figure 1 , 2 As shown, the guide plate 400 has a central channel 430 at its center, and the burner has a fuel oil channel communicating with the central channel 430. A fuel oil nozzle 431 is mounted on the fuel oil channel. When fuel oil is required, it is delivered to the combustion chamber through the central channel 430 at a certain pressure and with a specific injection method via the fuel oil nozzle 431. By providing both fuel oil and pulverized coal as fuel options, users can flexibly choose the lower-cost fuel based on market fuel price fluctuations, thereby reducing fuel procurement costs. For example, when fuel oil prices are relatively low, fuel oil can be used for combustion, reducing reliance on the more expensive pulverized coal and effectively controlling production costs. Fuel can be easily switched under different production scenarios and operating conditions, meeting diverse needs in the production process. Whether dealing with sudden fuel supply problems or adjusting burner operating parameters according to the production process requirements of different products, this can be achieved by flexibly selecting either fuel oil or pulverized coal, improving the overall production flexibility and ability to cope with complex situations in the asphalt mixing plant. In other optional embodiments, the guide plate 400 may not have a central channel 430.

[0024] like Figure 1As shown, the burner head 200 contains a spacer 500 shorter than the burner head 200, and a cooling channel 510 is provided between the spacer 500 and the inner wall of the burner head 200. Through preliminary combustion within the spacer 500, the fuel is partially oxidized and heated. When it enters the main combustion zone of the burner head 200, it can mix more quickly and thoroughly with the remaining air and complete the combustion reaction, thereby improving the overall combustion efficiency and converting more fuel energy into effective heat energy. Part of the air in the combustion air duct is diverted to the cooling channel 510, which effectively removes the high-temperature heat generated by combustion, preventing the burner head 200 from deforming or being damaged due to overheating, and protecting the key components of the burner. This is of great significance for extending the service life of the burner and ensuring its long-term stable operation, reducing the number of downtime maintenance caused by overheating failures. The air in the cooling channel 510 can provide air for further combustion of the fuel within the burner head 200.

[0025] like Figure 1 As shown, an ignition assembly 600 is installed in the combustion air channel between the blower 100 and the guide plate 400. The ignition assembly 600 includes a high-voltage ignition electrode and an ignition fuel pipe. After the burner is started and energized, the high-voltage ignition electrode in the ignition assembly 600 generates a high voltage at its tip, thereby forming an electric spark. At the same time, the ignition fuel pipe delivers dedicated ignition fuel to the ignition area. The combustion air blown from the blower 100 carries air through this area and mixes with the ignition fuel to form a combustible mixture. Under the action of the electric spark generated by the high-voltage ignition electrode, the combustible mixture is ignited, initiating the initial combustion reaction. If fuel oil combustion is subsequently selected, the fuel oil is injected into the combustion air channel through the fuel gun 431; or if pulverized coal combustion is selected, the pulverized coal enters the combustion air area through the pulverized coal channel. The flame generated by the ignited fuel will further ignite these fuels, allowing the combustion reaction to continue.

[0026] Furthermore, the ignition assembly 600 is a three-stage ignition assembly 600 for liquefied petroleum gas (LPG). The three-stage LPG ignition assembly 600 progressively enhances ignition energy through three stages, from generating a small ignition source to forming a powerful ignition flame, greatly improving ignition reliability. Under various complex operating conditions, such as low-temperature environments, high-humidity air, and unstable fuel quality, successful ignition is ensured, virtually eliminating the possibility of ignition failure. In other optional embodiments, the ignition assembly 600 can also be a single-stage ignition assembly 600.

[0027] Primary ignition stage: When the burner start signal is issued, the LPG three-stage ignition assembly 600 begins operation. First, in the primary ignition stage, the high-voltage generator within the assembly supplies power to the ignition electrodes, generating a high voltage at the electrode tips to form an electric spark. Simultaneously, a small amount of LPG is released into the ignition area through a dedicated primary LPG channel. Combustion-supporting air blown from the blower 100 mixes with this LPG, and under the action of the electric spark, the mixture is ignited, forming a small initial flame. This stage primarily aims to generate an initial ignition source, preparing for subsequent ignition.

[0028] Intermediate ignition stage: After the primary flame ignites, its heat triggers the intermediate ignition control device. At this time, the intermediate liquefied gas channel opens, and an appropriate amount of liquefied gas is delivered to the vicinity of the primary flame. Due to the high temperature of the primary flame, the intermediate liquefied gas quickly mixes with the surrounding air and is ignited, allowing the flame size to expand. The intermediate ignition process further increases the temperature and energy of the ignition zone, creating more favorable conditions for the final ignition of the main fuel (a mixture of fuel oil or pulverized coal and air).

[0029] Advanced ignition stage: With the formation of the intermediate flame, the advanced ignition control element is activated. A large amount of liquefied gas is injected into the combustion zone through the advanced liquefied gas channel, where it mixes thoroughly with the combustion air continuously blown from the blower 100. The high temperature and energy of the intermediate flame are sufficient to ignite this large mixture, forming a powerful ignition flame. This powerful flame can quickly and effectively ignite the fuel droplets or coal powder and air mixture entering the combustion air channel, ensuring a smooth start-up of the main combustion process.

[0030] like Figure 1 As shown, a fixing seat 710 is provided on the inner wall of the ventilation duct 300, and a fixing rod 720 is adjustablely mounted on the fixing seat 710. The guide plate 400 is fixed to the fixing rod 720. When it is necessary to adjust the position of the guide plate 400, the adjustable connection mechanism between the fixing seat 710 and the fixing rod 720 is used. For example, with a structure having an adjustment slot, the fixing device can be loosened, the fixing rod 720 can be moved to a suitable position in the slot and then re-fixed to achieve axial and angular adjustment. Through this adjustment method, the relative position and angle of the airflow between the guide plate 400 and the ventilation duct 300 can be changed to optimize the mixing effect of air and fuel. In other optional embodiments, the guide plate 400 can also be directly welded to the burner head 200.

[0031] Furthermore, the ventilation duct 300 is provided with an inspection port, which has a door and an observation port. The observation port has a transparent element, not shown in the figure. This facilitates maintenance and real-time monitoring.

[0032] like Figure 1As shown, the burner includes a pulverized coal inlet pipe 800, which is vertically arranged and connected to the pulverized coal channel. The pulverized coal inlet pipe 800 is offset from the lower center of the pulverized coal channel. This offset changes the initial direction and position of the pulverized coal when it enters the channel. When the pulverized coal enters the channel from the inlet pipe, it experiences a certain lateral offset due to the offset from the center, creating a more complex mixing state with the air entering the outer channel 410 from the ventilation pipe 300. This asymmetrical entry method causes the pulverized coal to break the conventional symmetrical mixing pattern when mixing with air, generating a stronger turbulence effect and allowing for more thorough contact between the pulverized coal and air in the initial mixing stage. In other optional embodiments, the pulverized coal inlet pipe 800 can also be connected to the middle position of the bottom of the pulverized coal channel.

Claims

1. A pulverized coal burner suitable for the drying drum of an asphalt mixing plant, comprising a blower (100), a burner head (200), and a ventilation pipe (300) connecting the blower (100) and the burner head (200), wherein the burner head (200) has a combustion chamber, characterized in that, The burner head (200) is equipped with a guide plate (400). The guide plate (400) is provided with an outer channel (410) and an inner channel (420) that are separated from each other. The burner is provided with a pulverized coal channel that communicates with the inner channel (420). The ventilation pipe (300) is connected to the outer channel (410). The outer channel (410) is provided with an inclined first guide vane (411), and the inner channel (420) is provided with an inclined second guide vane (421). The first guide vane (411) and the second guide vane (421) are inclined in opposite directions so that the pulverized coal and air rotate in opposite directions after passing through the guide plate (400).

2. A pulverized coal burner suitable for the drying drum of an asphalt mixing plant according to claim 1, characterized in that, The guide plate (400) has a central channel (430) at its center, and the burner has a fuel channel that communicates with the central channel (430). A fuel gun (431) is installed on the fuel channel.

3. A pulverized coal burner suitable for the drying drum of an asphalt mixing plant according to claim 1, characterized in that, The burner head (200) is equipped with a spacer (500) shorter than the burner head (200), and a cooling channel (510) is provided between the spacer (500) and the inner wall of the burner head (200).

4. A pulverized coal burner suitable for the drying drum of an asphalt mixing plant according to claim 1, characterized in that, An ignition assembly (600) is provided on the combustion air passage between the fan (100) and the guide plate (400).

5. A pulverized coal burner suitable for the drying drum of an asphalt mixing plant according to claim 4, characterized in that, The ignition assembly (600) is a three-stage ignition assembly (600) for liquefied gas.

6. A pulverized coal burner suitable for the drying drum of an asphalt mixing plant according to claim 1, characterized in that, The ventilation pipe (300) has a fixed seat (710) on its inner wall, and a fixed rod (720) is adjustablely installed on the fixed seat (710). The guide plate (400) is fixed on the fixed rod (720).

7. A pulverized coal burner suitable for the drying drum of an asphalt mixing plant according to claim 1, characterized in that, The ventilation duct (300) is provided with an inspection port, the inspection port is provided with a door, the door is provided with an observation port, and the observation port is provided with a transparent part.

8. A pulverized coal burner suitable for the drying drum of an asphalt mixing plant according to claim 1, characterized in that, The burner includes a pulverized coal inlet pipe (800), which is vertically arranged and connected to the pulverized coal channel, and the pulverized coal inlet pipe (800) is offset from the lower center of the pulverized coal channel.

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