A feeding mechanism for a biomass boiler and a biomass boiler

Abstract

This invention discloses a feeding mechanism for a biomass boiler and a biomass boiler, relating to the field of biomass energy technology. It includes a hopper connected to the discharge end of a hopper, with one side wall of the hopper being a concave arc-shaped plate. A material roller is rotatably mounted inside the hopper, and a rotating shaft is also included. The material roller is eccentrically mounted on the rotating shaft. This feeding mechanism and biomass boiler, relying on the eccentric rotor and arc-shaped plate's cooperative structure, combined with multiple sets of hooks arranged alternately and bent in opposite directions on the outer circumference of the rotor and the concave arc surface of the arc-shaped plate, simultaneously subject the material to progressive compression through a gradually changing gap and the staggered tearing action of the two sets of hooks during material transport. This only breaks down the cohesive force of agglomerated fuel to disperse the clusters, without rigidly crushing individual biomass fuel particles, thus reducing the generation of ultrafine powder at the source. This effectively solves the defects of existing rigid crushing schemes that easily exacerbate fly ash entrainment in the furnace and coking on the heating surface.

Description

Technical Field

[0001] This invention relates to the field of biomass energy technology, specifically to a feeding mechanism for a biomass boiler and a biomass boiler. Background Technology

[0002] As is generally known, a biomass boiler is a type of boiler that uses biomass energy as fuel. Biomass boilers are classified into biomass steam boilers, biomass hot water boilers, biomass hot air furnaces, biomass thermal oil furnaces, vertical biomass boilers, horizontal biomass boilers, etc.

[0003] For example, the invention patent with publication number CN115614729A, publication date January 17, 2023, and titled "A Combustion Boiler Suitable for Biomass Pellet Fuel," includes a boiler body. An operation panel is installed on the outer wall of the boiler body, a feed inlet is installed on the top side of the boiler body, and a partition is installed on the inner wall of the boiler body, dividing the inner cavity of the boiler body into a fuel compartment and a heating compartment. In this invention, after the biomass pellet fuel enters the crushing compartment, it is crushed by a crushing unit, separating the agglomerated fuel into pellets.

[0004] The shortcoming of existing technology is that rigid crushing units are prone to over-crushing biomass fuel, producing a large amount of ultrafine powder, which will exacerbate the problems of fly ash entrainment in the furnace and coking on the heating surface, reducing the boiler's operational stability and thermal efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a feeding mechanism for a biomass boiler and a biomass boiler to overcome the above-mentioned shortcomings in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A feeding mechanism for a biomass boiler includes a material storage bin connected to the discharge end of a hopper. One side wall of the material storage bin is a concave arc-shaped plate. A material roller is rotatably arranged inside the material storage bin. The mechanism also includes a rotating shaft driven to rotate. The material roller is located on the rotating shaft and is eccentrically rotatable. During the eccentric rotation, there is a material channel with the smallest cross-section between the material roller and the arc plate, and the discharge end of the hopper is fixedly provided with a guide plate extending from the end into the material channel; The outer peripheral wall of the material roller and the concave arc surface of the arc plate are both provided with hook sets, and the hooks of the hook sets on the two are staggered.

[0007] As a further description of the above technical solution: the angle formed by the bending of the hooks on the material roller and the hooks on the arc plate is opposite.

[0008] As a further description of the above technical solution: the bending angle of the hook on the arc plate faces downward.

[0009] As a further description of the above technical solution: the guide plate has several clearance grooves on its body for the hooks to pass through.

[0010] As a further description of the above technical solution: the rotating shaft is rotatably installed on the side wall of the material storage bin, and a sliding seat is coaxially fixed to the shaft body of the rotating shaft that extends into the material storage bin; the sliding seat has parallel and symmetrically opened waist grooves, and the material roller is slidably disposed in the waist grooves.

[0011] As a further description of the above technical solution: it also includes an adjustment mechanism, which is used to make the eccentricity between the material roller and the rotating shaft adjustable.

[0012] As a further description of the above technical solution: the adjustment mechanism includes a lead screw, which is threadedly engaged with a threaded hole opened at the center of the rotating shaft, and extends into the receiving cavity opened inside the material roller, and then meshes with a toothed plate provided on the inner wall of the receiving cavity through a toothed post provided on it.

[0013] As a further description of the above technical solution: it also includes a three-phase asynchronous motor, which is connected to the rotating shaft via a synchronous belt drive.

[0014] As a further description of the above technical solution: when the material channel is at its minimum cross-section, the hooks on the material roller and the hooks on the arc plate have a coinciding surface.

[0015] A biomass boiler includes the feeding mechanism for a biomass boiler described above.

[0016] In the above technical solution, the feeding mechanism and biomass boiler provided by the present invention rely on the matching structure of the eccentrically set rotor and the arc plate, combined with multiple sets of hooks arranged alternately and bent in opposite directions on the outer periphery of the rotor and the concave arc surface of the arc plate. During the material conveying process, the material is simultaneously subjected to the progressive compression of the gradual gap and the staggered tearing action of the two sets of hooks. This only breaks the cohesive force of the agglomerated fuel to disperse the agglomerates, without rigidly crushing and pulverizing individual biomass fuel particles, thereby reducing the generation of ultrafine powder from the source. This effectively solves the defects of existing rigid crushing schemes that easily aggravate the entrainment of fly ash in the furnace and coking on the heating surface. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of the present invention; Figure 2 Provided for embodiments of the present invention Figure 1 Enlarged structural diagram at point A; Figure 3 This is a schematic diagram of the structure of the hopper provided in an embodiment of the present invention; Figure 4 Provided for embodiments of the present invention Figure 3 A cross-sectional structural diagram; Figure 5 This is a schematic diagram of the roller mounting structure provided in an embodiment of the present invention; Figure 6 Provided for embodiments of the present invention Figure 5 Enlarged structural diagram at point B; Figure 7 This is a schematic diagram of the toothed column provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of the arc-shaped plate provided in an embodiment of the present invention; Figure 9 Provided for embodiments of the present invention Figure 3 Top view of the structure; Figure 10 This is a schematic diagram of the structure of the material roller rotation stage provided in an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures: 1. Hopper; 11. Biomass boiler; 2. Storage bin; 3. Material roller; 31. Receiving cavity; 4. Hook; 5. Arc plate; 6. Rotating shaft; 61. Sliding seat; 611. Waist groove; 62. Guide bolt; 7. Adjusting mechanism; 71. Screw; 711. Tooth column; 72. Tooth plate; 8. Guide plate; 81. Circumvention groove; 9. Three-phase asynchronous motor; 91. Synchronous belt; 92. Synchronous pulley. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0021] Please see Figure 1-10 The present invention provides a technical solution: a feeding mechanism for a biomass boiler, applied to the feeding end of a biomass boiler 11, which mainly includes a hopper 1, a material storage bin 2, a material roller 3, a hook 4, an arc plate 5, a rotating shaft 6, an adjusting mechanism 7, a guide plate 8, and a driving assembly.

[0022] The hopper 1 adopts a funnel-shaped structure that is wider at the top and narrower at the bottom. The top is an open feed end, and the bottom discharge end is sealed and connected to the storage bin 2 below. After being fed into the hopper 1, the biomass fuel falls into the storage bin 2 by its own weight. The storage bin 2 is a closed cavity structure. Its side wall facing the boiler furnace is integrally set as a concave arc plate 5. The concave arc surface of the arc plate 5 faces the internal cavity of the storage bin 2, and the curvature of the arc surface is adapted to the outer curvature of the material roller 3. The two work together to form a material channel for material passage.

[0023] Rotating shafts 6 are rotatably mounted on both side walls of the material storage bin 2 via bearings. The axis of the rotating shafts 6 is parallel to the arc axis of the arc plate 5. A sliding seat 61 is coaxially fixedly mounted on the shaft body of the rotating shafts 6, which extends into the material storage bin 2. The sliding seat 61 has a disc-shaped structure with two radially extending waist grooves 611 symmetrically opened on its disc surface. A guide bolt 62 is slidably inserted into each waist groove 611. The screw end of the guide bolt 62 passes through the waist groove 611 and is fixedly connected to the side end face of the material roller 3. This allows the material roller 3 to make radial displacement relative to the rotating shaft 6 along the extension direction of the waist groove 611, providing sliding guidance for eccentricity adjustment.

[0024] The material roller 3 is a cylindrical roller body, eccentrically mounted on the rotating shaft 6 and located on the concave side of the arc plate 5. As the material roller 3 rotates with the rotating shaft 6, the distance between its outer peripheral wall and the concave arc surface of the arc plate 5 continuously changes, forming a material channel with a cross-section that first decreases and then increases. This material channel has a section with the smallest cross-section for extrusion and de-agglomeration, which is used to apply progressive extrusion and tearing action to the agglomerated fuel.

[0025] Both the outer circumferential wall of the material roller 3 and the concave arc surface of the arc plate 5 are equipped with hook sets. Each hook set consists of multiple L-shaped bent hooks 4. Several hooks 4 are arranged in a circular array along the circumference of the material roller 3 to form a hook set; several hooks 4 are arranged in an array along the arc length direction of the concave arc surface of the arc plate 5 to form another hook set. The two sets of hooks 4 are staggered along the axial direction of the material roller 3, that is, the hooks 4 on the material roller 3 correspond to the axial gap positions of two adjacent hooks 4 on the arc plate 5. During the rotation of the material roller 3, the two sets of hooks 4 interlock and misalign with each other, forming a misaligned material dismantling and unpacking relationship for the passing material.

[0026] Furthermore, the hooks 4 on the material roller 3 and the hooks 4 on the arc-shaped plate 5 have opposite bending angles; specifically, the bending angle of the hooks 4 on the arc-shaped plate 5 faces downwards, while the bending angles of the hooks 4 on the material roller 3 and the hooks 4 on the arc-shaped plate 5 are opposite. The fixed hooks 4 on the arc-shaped plate 5 have downward bending angles, forming a barbed obstruction on the clumps of fuel traveling along the arc surface, restricting them from sliding freely under their own weight; the rotating hooks 4 on the material roller 3 have upward bending angles, embedding themselves into the clumps as the roller rotates, applying a continuous pulling force with rotation, constantly scraping their surface, causing surface material to fall off and reducing their volume until they can enter the material channel.

[0027] When the material channel is in the extrusion and de-agglomeration section with the smallest cross-section, the hooks 4 on the material roller 3 and the hooks 4 on the arc plate 5 form a partially overlapping shearing mating surface in the axial projection. As the material roller 3 rotates eccentrically with the rotating shaft 6, the cross-section of the material channel between it and the arc plate 5 changes continuously along the material travel direction, first narrowing and then widening. As the material travels from the feed end to the extrusion and de-agglomeration section, the channel gap gradually decreases. Correspondingly, the overlapping and interlocking depth of the rotating hooks 4 on the material roller 3 and the fixed hooks 4 on the arc plate 5 in the axial projection gradually increases from shallow to deep. The two sets of L-shaped hooks 4 with opposite bends are arranged alternately along the axial direction, so that the rotating hooks 4 and the fixed hooks 4 form a compound relative motion of rubbing and interlocking, which produces a continuous kneading and grinding effect on the agglomerated fuel sandwiched between them. This can form a stronger tearing and shearing effect on the agglomerated fuel, as well as a progressive rubbing effect, thereby improving the de-agglomeration efficiency.

[0028] A guide plate 8 is fixedly installed at the discharge end of the hopper 1. The guide plate 8 is arranged at an angle, with its upper end fixedly connected to the side wall of the discharge end of the hopper 1 and its lower end extending downward to the feeding section between the arc plate 5 and the material roller 3. It is used to guide the material falling from the hopper 1 to the feeding end of the material channel, preventing the material from sliding directly from the non-working side of the material roller 3, and ensuring that all the material enters the material channel to complete the unpacking and conveying. Several clearance grooves 81 are provided on the plate body of the guide plate 8. The clearance grooves 81 are arranged at intervals along the width direction of the guide plate 8. The number and position of the clearance grooves 81 correspond one-to-one with the rotor hook units on the material roller 3. The extension trajectory of the clearance grooves 81 is adapted to the circumferential rotation path of the corresponding hooks 4 on the material roller 3. When the hooks 4 rotate with the material roller 3 and pass through the position of the guide plate 8, they can be embedded in the clearance grooves 81 to pass through, eliminating the motion interference between the guide plate 8 and the hooks 4, and reducing the gap between the guide plate 8 and the material roller 3.

[0029] The material roller 3 has an internal cavity 31, within which is an adjusting mechanism 7 for adjusting the eccentricity of the material roller 3. The adjusting mechanism 7 includes a lead screw 71, which is arranged axially along the rotating shaft 6 and threaded into a threaded hole at the center of the rotating shaft 6. One end of the lead screw 71 extends outward from the rotating shaft 6 and has a polygonal post for connecting an external adjusting tool; the other end extends into the cavity 31 of the material roller 3, and a toothed post 711 is coaxially fixedly mounted at this end. A toothed plate 72 is correspondingly fixedly mounted on the inner wall of the cavity 31, and the toothed post 711 meshes with the toothed plate 72.

[0030] When the eccentricity needs to be adjusted, the outer end of the lead screw 71 is rotated. The lead screw 71 is fed axially through the threaded engagement with the rotating shaft 6, which drives the toothed column 711 at the end to move axially synchronously. The toothed column 711 drives the toothed plate 72 to move radially through meshing transmission, which in turn drives the entire material roller 3 to slide radially along the direction of the waist groove 611, so as to realize the stepless adjustment of the eccentricity between the material roller 3 and the rotating shaft 6. This allows for adjustment of the minimum cross-sectional size of the material channel to adapt to biomass fuels with different particle sizes and different agglomeration strengths.

[0031] A three-phase asynchronous motor 9 is fixedly installed on the side of the hopper 1. The output shaft of the three-phase asynchronous motor 9 and the extended end of the rotating shaft 6 are both fixedly fitted with synchronous pulleys 92. A synchronous belt 91 is wound between the two synchronous pulleys 92. After the three-phase asynchronous motor 9 starts, it drives the rotating shaft 6 to rotate at a constant speed through the meshing transmission between the synchronous belt 91 and the synchronous pulleys 92, thereby providing power for the rotation of the material roller 3.

[0032] It should be noted that the complete work process is as follows: After biomass fuel is fed into the top of hopper 1, it falls under its own weight to the guide plate 8. Guided directionally by the inclined guide plate 8, it enters the material channel feed end between the arc plate 5 and the material roller 3. A three-phase asynchronous motor 9 drives the rotating shaft 6 to rotate via a synchronous belt, which in turn drives the material roller 3 to rotate eccentrically via the sliding seat 61 and guide bolt 62. The hooks 4 on the material roller 3 continuously scrape the surface of any clumps of material that cannot enter the material channel, causing the surface material to fall off and reducing its volume until it can enter the material channel.

[0033] As the feed roller 3 rotates eccentrically, the cross-section of the material channel gradually decreases during the material's movement, entering the extrusion and de-agglomeration zone. The feed roller 3 and the staggered, oppositely oriented hooks 4 on the arc plate 5 work together to create a staggered tearing and shearing effect on the agglomerated fuel. Combined with the progressive extrusion effect brought by the eccentric structure, the agglomerated fuel is broken down into its original granular state without excessively crushing the material to produce ultrafine powder. The de-agglomerated material continues to move with the feed roller 3, and the cross-section of the material channel gradually increases. The material is discharged from the discharge end by its own weight and the pushing force, entering the boiler furnace for combustion.

[0034] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A feeding mechanism for a biomass boiler, comprising a material storage bin (2) connected to the discharge end of a hopper (1), characterized in that: The material storage bin (2) has a concave arc-shaped plate (5) on one side wall. A material roller (3) is rotatably arranged inside the material storage bin (2). It also includes a rotating shaft (6) driven to rotate. The material roller (3) is located on the rotating shaft (6) and is eccentrically arranged to rotate. During the eccentric rotation process, there is a material channel with the smallest cross-section between the material roller (3) and the arc plate (5), and the discharge end of the hopper (1) is fixedly provided with a guide plate (8) extending from the end into the material channel. The outer peripheral wall of the material roller (3) and the inner concave arc surface of the arc plate (5) are both provided with a set of hooks, and the hooks (4) of the hook sets on the two are staggered.

2. The feeding mechanism for a biomass boiler according to claim 1, characterized in that, The angle formed by the bend of the hook (4) on the material roller (3) and the hook (4) on the arc plate (5) is opposite.

3. The feeding mechanism for a biomass boiler according to claim 1, characterized in that, The bend angle of the hook (4) on the arc plate (5) is downward.

4. The feeding mechanism for a biomass boiler according to claim 1, characterized in that, The guide plate (8) has several clearance grooves (81) for the hook (4) to pass through.

5. The feeding mechanism for a biomass boiler according to claim 1, characterized in that, The rotating shaft (6) is rotatably installed on the side wall of the material storage bin (2). The shaft of the rotating shaft (6) extends into the material storage bin and is coaxially fixed with a sliding seat (61). The sliding seat (61) is provided with parallel and symmetrical waist grooves (611), and the material roller (3) is slidably disposed in the waist grooves (611).

6. The feeding mechanism for a biomass boiler according to claim 1, characterized in that, It also includes an adjustment mechanism (7) for making the eccentricity between the material roller (3) and the rotating shaft (6) adjustable.

7. A feeding mechanism for a biomass boiler according to claim 6, characterized in that, The adjustment mechanism (7) includes a lead screw (71), which is threadedly engaged with a threaded hole at the center of the rotating shaft (6) and extends into the receiving cavity (31) inside the material roller (3), and then meshes with a toothed plate (72) on the inner wall of the receiving cavity (31) through a toothed column (711) provided thereon.

8. The feeding mechanism for a biomass boiler according to claim 1, characterized in that, It also includes a three-phase asynchronous motor (9), which is connected to the rotating shaft (6) via a synchronous belt (91).

9. A feeding mechanism for a biomass boiler according to claim 1, characterized in that, When the material channel is at its smallest cross-section, the hook (4) on the material roller (3) and the hook (4) on the arc plate (5) have a overlapping surface.

10. A biomass boiler, characterized in that, The feeding mechanism for a biomass boiler as described in any one of claims 1-9 above.

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