Self-cleaning boiler air preheater

Abstract

The utility model relates to the field of boiler auxiliary equipment, concretely is a kind of self-cleaning ash formula boiler air preheater, rotation is arranged in the heat exchange pipe with rotating rod, rotating rod is fixedly connected with several bristles at interval on it, bristle is contacted with the inner wall of heat exchange pipe, preheater main part top is fixedly connected with driving motor, driving motor is used to drive rotating rod rotation, preheater main part lower end is fixedly connected with ash outlet, ash outlet lower end is detachably connected with dust collecting box.The utility model is rotated by being arranged with rotating rod in the heat exchange pipe, bristle that is contacted with the inner wall of heat exchange pipe is fixedly connected on rotating rod, preheating tube inner wall is brushed using driving motor to drive rotating rod rotation, can realize heat exchange tube inner automatic dust cleaning, dust cleaning is complete, and equipment does not need to be disassembled again to carry out dust cleaning, can realize dust cleaning and the continuity of production.

Description

Technical Field

[0001] This utility model relates to the field of boiler auxiliary equipment, specifically a self-cleaning boiler air preheater. Background Technology

[0002] Boiler air preheaters are key equipment for recovering waste heat from flue gas and improving boiler thermal efficiency. They utilize the high-temperature flue gas from the boiler flue to preheat the combustion air entering the furnace through heat exchange elements. However, flue gas contains a large amount of fly ash and sulfides, which easily deposit on the surface of the preheater's heat exchange elements, forming ash buildup and even causing low-temperature corrosion and ash blockage. Ash buildup severely reduces the preheater's heat exchange efficiency, increases flue gas flow resistance, and leads to a decrease in heat exchange efficiency, sometimes even forcing unplanned boiler shutdowns. During the operation of the boiler air preheater, maintaining the cleanliness of the heat exchange tube bundle is crucial to ensuring equipment efficiency and extending its service life; therefore, cleaning the ash buildup on the heat exchange elements is particularly important. Currently, common methods for cleaning heat exchange elements in preheaters include periodic manual cleaning, high-pressure water washing, and mechanical vibration. While manual cleaning can remove dust from the tube bundle surface, it is labor-intensive, inefficient, and cannot achieve continuous cleaning. High-pressure water washing can remove some dust, but it consumes a lot of water and causes corrosion to the equipment. Mechanical vibration can loosen dust to some extent, but the vibration force is limited and cannot completely remove the accumulated dust inside the tube bundle. Therefore, there is a need to develop a self-cleaning boiler air preheater that can thoroughly clean and ensure continuous cleaning. Utility Model Content

[0003] To address the above technical problems, this utility model provides a self-cleaning boiler air preheater that thoroughly cleans and ensures continuous cleaning, thereby solving the problem that existing preheater cleaning methods cannot achieve continuous cleaning and have limited cleaning effects.

[0004] To solve the above-mentioned technical problems, the present invention provides a self-cleaning boiler air preheater, comprising a preheater body, wherein tube sheets are fixedly connected to the upper and lower parts of the preheater body, and a plurality of heat exchange tubes are fixedly connected between the upper and lower tube sheets. A flue gas inlet is connected to the upper end cap of the preheater body, and a flue gas outlet is connected to the lower end cap. An air outlet is connected to the upper part of the preheater body, and an air inlet is connected to the lower part. A rotating rod is rotatably arranged inside the heat exchange tubes, and a plurality of bristles are fixedly connected at intervals on the rotating rod. The bristles are in contact with the inner wall of the heat exchange tubes. A drive motor is fixedly connected to the top of the preheater body, and the drive motor is used to drive the rotating rod to rotate. An ash outlet is fixedly connected to the lower end of the preheater body, and an ash collection box is detachably connected to the lower end of the ash outlet.

[0005] Furthermore, a connecting frame is fixedly connected to the tube sheet, and the upper and lower ends of the rotating rod are rotatably connected to the connecting frame through bearings.

[0006] Furthermore, the output shaft of the drive motor extends into the preheater body and is fixedly connected to a drive wheel, and a driven wheel is fixedly connected to the upper end of the rotating rod, and the drive wheel drives the driven wheel to rotate.

[0007] Furthermore, a dust collection hopper is fixedly connected to the bottom of the connecting frame located below, and the bottom of the dust collection hopper is connected to the dust outlet.

[0008] Furthermore, a tapered dust guide head is fixedly connected to the lower end of the rotating rod, and the lower end of the dust guide head is rotatably connected to the connecting frame.

[0009] This utility model has the following advantages compared with the prior art:

[0010] 1. This utility model achieves automatic and thorough cleaning of the heat exchange tube by rotating a rotating rod inside the heat exchange tube and fixing brush bristles that contact the inner wall of the heat exchange tube on the rotating rod. The rotating rod is driven by a drive motor to brush the inner wall of the heat exchange tube, thus achieving automatic cleaning of the heat exchange tube. The cleaning is thorough and there is no need to disassemble the equipment for cleaning, thus achieving continuity of cleaning and production.

[0011] 2. This utility model ensures that the accumulated ash completely enters the ash collection box by connecting the ash collection hopper to the bottom of the connecting frame below. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model.

[0013] Figure 2 This is a view of the internal structure of the cooler.

[0014] In the diagram: 1. Preheater body, 2. Tube sheet, 3. Heat exchange tube, 4. Rotating rod, 5. Brush, 6. Connecting frame, 7. Drive motor, 8. Ash guide head, 9. Ash outlet, 10. Ash collection box, 11. Flue gas inlet, 12. Flue gas outlet, 13. Air outlet, 14. Air inlet, 15. Ash collection hopper. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings.

[0016] During boiler operation, to fully utilize the waste heat of boiler flue gas and improve operational efficiency, an air preheater is typically used in conjunction with high-temperature flue gas to preheat the air entering the boiler. However, the flue gas contains a large amount of fly ash and sulfides, which easily deposit on the surface of the heat exchange elements of the preheater, forming ash buildup and even causing low-temperature corrosion and ash blockage. This leads to a decrease in the heat exchange efficiency and a deterioration in the heat exchange effect of the preheater, thus requiring regular cleaning of the heat exchange tubes. Existing methods for cleaning the heat exchange tubes in preheaters typically involve manual cleaning, high-pressure water flushing, and mechanical vibration cleaning. Manual cleaning requires disassembling the heat exchange tubes, while high-pressure water flushing and mechanical vibration are energy-intensive, costly, and prone to incomplete cleaning. Furthermore, all of these methods require shutdown for cleaning, affecting the continuity of equipment operation. Therefore, it is necessary to develop a self-cleaning boiler air preheater that ensures thorough cleaning and continuous operation. Figure 1 The self-cleaning ash-removing boiler air preheater shown adopts a conventional tubular heat exchanger structure, including a preheater body 1. Tube sheets 2 are fixedly connected to the upper and lower parts of the preheater body 1. Several heat exchange tubes 3 are fixedly connected between the upper and lower tube sheets 2. A flue gas inlet 11 is connected to the upper end cap of the preheater body 1, and a flue gas outlet 12 is connected to the lower end cap. An air outlet 13 is connected to the upper part of one side of the preheater body 1, and an air inlet 14 is connected to the lower part of the other side. This enables counter-current heat exchange between high-temperature flue gas and air, improving heat exchange efficiency. A rotating rod 4 is rotatably installed inside the heat exchange tubes 3. A connecting frame 6 is fixedly connected to the top of the upper tube sheet 2. Several through holes for flue gas and ash passage are opened on the connecting frame 6. The lower tubes... A connecting frame 6 is fixedly connected to the bottom of plate 2. The upper and lower ends of the rotating rod 4 are rotatably connected to the connecting frame 6 through bearings. Several bristles 5 are fixedly connected to the rotating rod 4 at an annular interval. The bristles 5 are inclined downward and contact the inner wall of the heat exchange tube 3. A mounting bracket is fixedly connected to the top of the preheater body 1. A drive motor 7 is bolted to the mounting bracket. The output shaft of the drive motor 7 is downward and connected to the input end of the reducer. The output end of the reducer is downward and extends into the preheater body 1. A drive wheel is fixedly connected to the output end of the reducer. A driven wheel is fixedly connected to the upper end of the rotating rod 4. The drive wheel drives the driven wheel to rotate. An ash outlet 9 is fixedly connected to the lower end of the preheater body 1. An ash collection box 10 is connected to the lower end of the ash outlet 9. The ash collection box 10 is connected to the flange of the ash outlet 9.

[0017] In this embodiment, both the driving wheel and the driven wheel are gears, which drive the rotating rod 4 to rotate through gear meshing. The driving wheel and the driven wheel can also be pulleys. The driving wheel adopts a multi-layered pulley, which is connected to the driven wheel through belts.

[0018] To prevent the scraped ash from accumulating on the connecting frame 6, a tapered ash guide head 8 is fixedly connected to the lower end of the rotating rod 4. The lower end of the ash guide head 8 is rotatably connected to the connecting frame 6 via a bearing, and the bottom edge of the ash guide head 8 is connected to a through hole for ash discharge on the connecting frame 6.

[0019] In another embodiment, such as Figure 2 The self-cleaning ash-collecting boiler air preheater shown differs from the previous embodiment in that an ash collection hopper 15 is fixedly connected to the bottom of the lower connecting frame 6, and the bottom of the ash collection hopper 15 is connected to the ash outlet 9.

[0020] Based on the addition of the ash collection hopper 15, an ultrasonic vibration system can be added to allow the accumulated ash to quickly enter the ash collection box 10. An ultrasonic vibrating plate is installed on the ash collection hopper 15, and an ultrasonic generator is connected to an ultrasonic transducer. At the same time, the ultrasonic transducer is connected to the ultrasonic vibrating plate to prevent ash from accumulating in the ash collection hopper 15.

[0021] The working principle of this embodiment is as follows:

[0022] During boiler air preheating, the boiler high-temperature flue gas outlet is connected to the flue gas inlet 11 via a pipeline, the flue gas outlet 12 is connected to the plant's tail gas treatment system via a pipeline, the air inlet 14 is connected to the air pump via a pipeline, and the air outlet 13 is connected to the boiler's air supply port via a pipeline. The air is preheated using the high-temperature flue gas and then supplied to the boiler. During operation, the drive motor 7 is started and run for a period of time at intervals, during which air preheating can continue without stopping the machine. The drive motor 7 drives the rotating rod 4 to rotate, and the rotating rod 4 drives the brush 5 to brush the inner wall of the heat exchange tube 3, causing the accumulated ash to fall. Under the action of the ash guide head 8 and the ash collection hopper 15, the accumulated ash enters the ash collection box 10.

Claims

1. A self-cleaning boiler air preheater, comprising a preheater body (1), wherein tube sheets (2) are fixedly connected to the upper and lower parts of the preheater body (1), and a plurality of heat exchange tubes (3) are fixedly connected between the upper and lower tube sheets (2), a flue gas inlet (11) is connected to the upper end cap of the preheater body (1), a flue gas outlet (12) is connected to the lower end cap, and an air outlet (13) is connected to the upper part of the preheater body (1) and an air inlet (14) is connected to the lower part, characterized in that: A rotating rod (4) is rotatably installed inside the heat exchange tube (3). Several bristles (5) are fixedly connected at intervals on the rotating rod (4). The bristles (5) are in contact with the inner wall of the heat exchange tube (3). A drive motor (7) is fixedly connected to the top of the preheater body (1). The drive motor (7) is used to drive the rotating rod (4) to rotate. An ash outlet (9) is fixedly connected to the lower end of the preheater body (1). An ash collection box (10) is detachably connected to the lower end of the ash outlet (9).

2. The self-cleaning boiler air preheater according to claim 1, characterized in that: A connecting frame (6) is fixedly connected to the tube sheet (2), and the upper and lower ends of the rotating rod (4) are rotatably connected to the connecting frame (6) through bearings.

3. The self-cleaning boiler air preheater according to claim 1, characterized in that: The output shaft of the drive motor (7) extends into the preheater body (1) and is fixedly connected to a drive wheel. The upper end of the rotating rod (4) is fixedly connected to a driven wheel, and the drive wheel drives the driven wheel to rotate.

4. The self-cleaning boiler air preheater according to claim 2, characterized in that: The bottom of the connecting frame (6) located below is fixedly connected to a dust collection hopper (15), and the bottom of the dust collection hopper (15) is connected to the dust outlet (9).

5. The self-cleaning boiler air preheater according to claim 2, characterized in that: The lower end of the rotating rod (4) is fixedly connected to a tapered ash guide head (8), and the lower end of the ash guide head (8) is rotatably connected to the connecting frame (6).

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