Multi-runner long-chain type scraper coal feeder and coal feeding system

Abstract

The invention discloses a multi-runner long-chain type scraper coal feeder and a coal feeding system, and belongs to the technical field of boiler coal feeding, the multi-runner long-chain type scraper coal feeder is characterized by comprising a coal feeding comb, a scraper, a coal falling port, a scraper splitter plate and a bottom plate; a coal feeding opening is formed in the upper portion of the foremost end of the bottom plate, a coal feeding comb and a scraper are arranged behind the coal feeding opening in the coal conveying direction, and the coal feeding comb is located at the position, close to the coal feeding opening, above the scraper. A coal falling opening is formed in the bottom plate; a plurality of scraper splitter plates are fixed on the bottom plate, and the number of the scraper splitter plates is one less than that of the coal dropping ports. According to the invention, the coal bed near the coal dropping port of the scraper is uniformly divided into a plurality of flow channels, so that only coal in a single flow channel falls into a single coal dropping port, the coal feeding of a hearth is uniform, no local high-temperature point is generated, and low-NOx operation is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of boiler coal feeding, and in particular relates to a multi-flow channel long chain scraper coal feeder and a coal feeding system. Background Art

[0002] Circulating fluidized bed boilers have excellent fuel adaptability, can burn low-quality coal, and have the characteristics of low original pollutant emissions, which has led to their rapid promotion and application. At present, fluidized bed boilers generally use scraper coal feeders to feed coal in a long chain. Multiple coal drop ports are arranged from front to back on the bottom plate of a single scraper (such as Figure 1 As shown in the figure, different coal outlets correspond to different coal feeding points in the dense phase area of ​​the circulating fluidized bed boiler. In addition, the current scraper feeder bottom plate has several coal outlets with uniform openings, and the lower part of the coal outlet is equipped with a plug-in door for adjustment. However, due to the high thickness of the coal seam in the scraper, the coal feeding amount at the front coal outlet of the scraper is large, and the coal feeding amount at the rear coal outlet is low due to the reduced coal seam thickness, so it is impossible to achieve uniform coal feeding at the front and rear. Even with the plug-in door installed below the coal outlet, it is impossible to achieve uniform coal feeding.

[0003] For example, the Chinese patent with publication number CN220321346U, named a scraper-type coal feeder, provides the following technical solutions: a scraper-type coal feeder includes a fixed plate and a flat plate, the two sides of the fixed plate are symmetrically connected to the limit plates, the lower end of the limit plates is fixedly connected to the guide plates, and the guide plates are slidably connected in the guide grooves opened on the side of the flat plate, and the flat plate is fixedly connected to the body through a fixed frame, and at the same time, the fixed plate and the movable plate are symmetrically opened on the opposite sides of the fixed plate and the movable plate. The middle part of the surface of the flat plate is opened with an adjustment groove, the adjustment screw is movably connected in the adjustment groove through a bearing, and the movable block is slidably connected in the adjustment groove through a screw-connected adjustment screw, and the upper surface of the movable block is fixedly connected to the movable plate, and at the same time, the two ends of the spring are respectively slidably connected to the movable plate and the fixed plate through the mounting plate. This patent takes into account the uneven coal feeding caused by the thick coal seam in the middle and the thin coal seams on both sides.

[0004] Uneven coal feeding in the furnace can cause many problems. First, it leads to deviation in coal combustion in front and behind the furnace, insufficient air volume in front of the furnace and excessive air volume in the back of the furnace, which affects the combustion economy. Second, uneven coal feeding can lead to local deflagration or local burnout difficulties, resulting in slagging in the furnace and affecting the stability of boiler operation. Third, uneven coal feeding leads to large deviations in the air-powder matching in the dense phase area, and local high-temperature points are prone to produce thermal NOx, which affects the environmental protection of boiler operation. Fourth, uneven coal feeding can lead to uneven temperature distribution in the furnace, which in turn affects the combustion stability and load regulation ability of the boiler. In severe cases, it may lead to poor load carrying capacity and large load fluctuations in the boiler, affecting the safety and economy of the boiler. Fifth, the incomplete combustion caused by uneven coal feeding will accumulate residues in the boiler, adhere to the boiler wall, and block the boiler gap, which will not only affect the normal operation of the boiler, but also increase the loss of the boiler and shorten the service life of the boiler. Summary of the invention

[0005] The present invention provides a multi-channel long-chain scraper coal feeder and a coal feeding system, which evenly divides the coal seam near the scraper coal dropping port into several channels to ensure that only coal from a single channel falls into the single coal dropping port, thereby ensuring uniform coal feeding in the furnace without the generation of local high-temperature points and low NOx operation.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: In the first aspect, the present invention provides a multi-channel long-chain scraper coal feeder, comprising a coal feeding comb, a scraper, a coal drop port, a scraper machine diverter plate and a bottom plate; the coal feeding port is located above the front end of the bottom plate, and a coal feeding comb and a scraper are arranged behind the coal feeding port along the coal transportation direction, and the coal feeding comb is located above the scraper and close to the coal feeding port; a coal drop port is opened on the bottom plate; a number of scraper machine diverter plates are fixed on the bottom plate, and the number of scraper machine diverter plates is one less than the number of coal drop ports.

[0007] Furthermore, the bottom plate is a stepped structure.

[0008] Furthermore, a scraper outer guard plate is arranged on the outer periphery of the bottom plate. Furthermore, the scraper coal feeder is provided with multiple layers of coal feeding combs arranged in staggered rows.

[0009] Furthermore, the coal feeding comb includes a bracket, and a plurality of comb teeth are fixedly connected to the lower end of the bracket.

[0010] Furthermore, the spacing between adjacent comb teeth is less than half of the flow channel width.

[0011] Furthermore, the coal feeding comb is perpendicular to the coal transportation direction, and the scraper conveyor diverter plate is arranged along the coal transportation direction.

[0012] Furthermore, the coal drop port is located behind the scraper. Furthermore, the scraper is driven by a motor.

[0013] In a second aspect, the present invention provides a coal feeding system, comprising the multi-channel long chain scraper coal feeder described in any one of the first aspect of the present invention.

[0014] Compared with the prior art, the present invention has at least the following beneficial technical effects: The scraper coal feeder provided by the present invention is provided with a coal feeding comb at the scraper entrance, and at the same time, scraper machine diverter plates are arranged according to the number of coal drop-out ports. N coal drop-out ports are arranged with N-1 diverter plates. The coal fed into the coal feeding port is raked evenly by the coal feeding comb teeth to ensure that the thickness of the coal layer on the entire scraper is uniform before entering each flow channel. The amount of coal in each flow channel and the coal drop-out port can be adjusted by adjusting the distance between the diverter plates. When the distances between the diverter plates in each flow channel are consistent, the amount of coal entering the furnace can be ensured to be the same, and thus the amount of coal entering the furnace at each coal drop-out port is consistent. The coal entering the furnace is fed into the diverter channel to ensure that the amount of coal fed in a single flow channel is the same, and thus uniform coal feeding at each coal feeding point in the boiler is ensured, thereby improving the combustion condition in the furnace, improving the stable operation of the boiler, avoiding the large-scale generation of NOx at local high-temperature points, and thus improving the environmental friendliness of the boiler operation.

[0015] At the same time, compared with the original long-chain coal feeder, the coal feeder of the present invention is of stepped type, the stroke of the coal entering the furnace and the scraper is reduced, the no-load distance is reduced, and energy is greatly saved.

[0016] Furthermore, the present invention has a simple structure and is easy to maintain. In the original long-chain coal feeder, the scraper carries coal particles and passes over the coal drop port, which may interfere with the scraper and the coal drop port, and may cause the scraper chain to tear. In the present invention, the tail end of the single scraper is the coal drop port, and there is no problem of interference between the scraper and the coal drop port.

[0017] Furthermore, the coal feeding comb includes a bracket and a plurality of comb teeth fixed at the lower end of the bracket, the spacing between adjacent comb teeth is less than half of the width of the flow channel, and there are at least two comb teeth in one flow channel. During the transportation of coal particles, the coal feeding comb can rake the coal particles more evenly without occupying too much space of the coal particles.

[0018] Furthermore, the coal feeding comb is perpendicular to the coal transportation direction, and the scraper conveyor diverter plate is arranged along the coal transportation direction. The two cooperate with each other to further ensure that the amount of coal in each flow channel is the same, and finally the amount of coal entering the furnace at each coal drop port is consistent. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an existing long chain scraper coal feeder; Figure 2 A schematic diagram of the structure of a scraper coal feeder provided in Example 2 of the present invention; Figure 3 This is a schematic diagram of the coal feeding comb structure provided in Example 4 of the present invention.

[0020] In the attached drawings: 1-coal feeding port, 2-coal feeding comb, 3-scraper, 4-scraper outer guard plate, 5-coal dropping port, 6-motor, 7-scraper diverter plate, 21, bracket; 22, comb teeth. DETAILED DESCRIPTION

[0021] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be another element centered thereon. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be another element centered thereon at the same time. The terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc. used herein indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0025] The present invention ensures that the coal feeding amount in a single flow channel is the same by feeding the coal into the furnace through a branch flow channel, thereby ensuring uniform coal feeding in the furnace, improving the combustion conditions in the furnace, improving the stability of boiler operation, avoiding the occurrence of large amounts of NOx generated at local high-temperature points, and thus improving the environmental friendliness of boiler operation.

[0026] Example 1 Reference Figure 2 The present embodiment provides a multi-channel long-chain scraper coal feeder, including a coal feeding comb 2, a scraper 3, a scraper outer guard plate 4, a coal drop port 5, a motor 6, a scraper diverter plate 7 and a bottom plate.

[0027] A coal feeding port 1 is arranged above the front end of the bottom plate. A coal feeding comb 2 is arranged behind the coal feeding port 1 along the coal transportation direction. A scraper outer guard plate 4 is arranged on the periphery of the bottom plate. A scraper 3 is installed on the bottom plate. A coal drop port 5 is arranged at the end of the bottom plate. The scraper 3 is driven by a motor 6. Several parallel scraper diverter plates 7 are welded on the bottom plate. The number of scraper diverter plates 7 is arranged according to the number of coal drop ports 5. If there are N coal drop ports, N-1 diverter plates are arranged. For example, Figure 2 As shown, three coal dropping ports 5 are provided, and two scraper diverter plates 7 are provided to divide the scraper into three flow channels; if there are four coal dropping ports 5, three scraper diverter plates 7 are provided to divide the scraper into four flow channels, and so on. Each component is described in detail below.

[0028] Coal feeding port 1, the coal particles after crushing and screening in the coal bunker fall into the scraper coal feeder from the coal feeding port 1 after passing through the weighing belt, and move from front to back driven by the scraper 3.

[0029] The coal particles falling from the coal feeding port 1 of the coal feeding comb 2 are distributed in a cone shape. The coal seam in the middle of the scraper coal feeder is thick, and the coal seam on both sides near the side plates 4 of the scraper coal feeder is thin. Therefore, the newly added coal feeding comb teeth 2 will rake the thickness of the coal seam evenly to ensure that the thickness of the coal seam is uniform before entering the diversion channel and contacting the middle diversion plate 7.

[0030] Preferably, in order to ensure that the thickness of the coal layer on the entire scraper is uniform before entering each flow channel, multiple layers of coal feeding combs 2 may be arranged in a staggered manner, and the coal feeding combs 2 are perpendicular to the transport direction of the coal particles.

[0031] The scraper 3 drives the coal seam to move from front to back and sends the coal seam into the coal drop port 5.

[0032] The outer guard plate 4 of the scraper conveyor isolates the external space from the internal space of the scraper coal feeder and provides support for the scraper 3 and coal particles.

[0033] The scraper 3 brings the coal particles to the coal drop port 5 and drops them into the furnace.

[0034] The motor 6 and the motor 3 are connected to the scraper 3 through a shaft, providing power for the scraper 3 to drive the coal particles to move from front to back.

[0035] The scraper diverter plate 7 is welded and connected to the bottom plate of the scraper coal feeder, and the entire scraper coal feeder is divided into several flow channels. Before entering each flow channel, the thickness of the incoming coal in the entire scraper has been roughly the same after passing through the coal feeding comb teeth 2. By controlling the distance between adjacent scraper diverter plates 7, the amount of coal entering the furnace at different coal feeding ports can be controlled. When the distance between the diverter plates 7 of each flow channel is consistent, the amount of coal entering the furnace can be guaranteed to be the same, and the coal feeding at each coal feeding point of the boiler can be guaranteed to be uniform. The length direction of the scraper diverter plate 7 is parallel to the transportation direction of the coal.

[0036] This embodiment provides a multi-channel long chain scraper coal feeder, the working method of which is as follows: Coal particles fall into the scraper coal feeder from the coal feeding port 1, and move from front to back driven by the scraper 3. At the same time, the coal feeding comb 2 rakes the uneven thickness of the coal seam to make the thickness of the coal seam uniform before entering the diversion channel and contacting the scraper machine diversion plate 7. Driven by the scraper 3, the coal particles enter different flow channels, and are brought to the coal dropping port 5 by the scraper 3 and fall into the furnace.

[0037] Example 2 Reference Figure 2 The present embodiment provides a multi-channel long-chain scraper coal feeder, including a coal feeding comb 2, a scraper 3, a scraper outer guard plate 4, a coal drop port 5, a motor 6, a scraper diverter plate 7 and a bottom plate.

[0038] The bottom plate is a three-step structure, and two parallel scraper diverter plates 7 are welded on the bottom plate. The length direction of the scraper diverter plates 7 is the same as the coal transportation direction. The two scraper diverter plates 7 divide the coal feeder into three flow channels, and the width of the three flow channels is equal. A coal drop port 5 is set at the end of each flow channel. The three flow channels are arranged in a stepped manner, and the front ends of different flow channels are aligned and the rear ends are at different positions. This stepped arrangement reduces the stroke of coal particles entering the furnace and the scraper, reduces the no-load distance, and can save energy loss during operation.

[0039] A scraper 3 is provided in each flow channel, and the scraper 3 is driven by a motor 6. The axes of the three scrapers 3 are parallel to each other, and the head ends of the three scrapers 3 are all located below the coal feeding port 1. A coal feeding comb 2 is provided above the front end of the scraper 3, and the lower end of the coal feeding comb 2 is higher than the upper end of the scraper 3. A scraper machine outer guard plate 4 is provided on the outer periphery of the bottom plate, and the scraper 3 is installed on the bottom plate. A coal drop port 5 is provided at the end of the bottom plate. All coal drop ports 5 are located behind the scraper 3 to avoid interference between the scraper and the coal drop port, thereby increasing the service life of the coal feeder.

[0040] Among them, the coal feeding comb 2 includes a bracket 21 and a plurality of comb teeth 22 fixed under the bracket 21. The comb teeth 22 are perpendicular to the transportation direction of the coal particles. All the comb teeth 22 can be arranged evenly or in different local densities according to the pushing shape of the coal particles. For example, it can be dense in the middle and sparse on both sides, or sparse in the middle and dense on both sides; it can also be a layout in which the density of the comb teeth gradually increases or decreases from one end to a section.

[0041] Preferably, the spacing between adjacent comb teeth 22 is less than half of the width of the flow channel. There are at least two comb teeth in one flow channel, which can rake the coal particles more evenly without occupying too much space for the coal particles.

[0042] This embodiment provides a multi-channel long chain scraper coal feeder, the working method of which is as follows: Coal particles fall into the scraper coal feeder from the coal feeding port 1, and the thickness of the coal seam is raked evenly by the comb teeth 22 of the coal feeding comb 2. Driven by the scraper 3, the coal particles move from the head end to the end. Under the joint action of the scraper 3 and the scraper machine diverter plate 7, the coal particles enter three flow channels of the same width, and are finally brought to the coal dropping port 5 and fall into the furnace.

[0043] Example 3 The present embodiment provides a multi-channel long-chain scraper coal feeder, comprising a coal feeding comb 2, a scraper 3, a scraper machine outer guard plate 4, a coal drop port 5, a motor 6 and a bottom plate.

[0044] The upper front end of the bottom plate is a coal feeding port 1, and a coal feeding comb 2 and a scraper 3 are arranged behind the coal feeding port 1. The coal feeding comb 2 is located above the front of the scraper 3. The outer periphery of the bottom plate is provided with a scraper machine outer guard plate 4. The end of the bottom plate is provided with a coal drop port 5, and the scraper 3 is driven by a motor 6. All coal drop ports 5 are located behind the scraper 3 to avoid interference between the scraper and the coal drop port, thereby increasing the service life of the coal feeder.

[0045] The coal feeding comb 2 includes a bracket 21 and a plurality of comb teeth 22 fixed under the bracket 21. All the comb teeth 22 are evenly arranged and perpendicular to the coal particle transportation direction. The spacing between adjacent comb teeth 22 is less than half of the flow channel width. There are at least two comb teeth in one flow channel, which can rake the coal particles more evenly without occupying too much space for the coal particles.

[0046] Preferably, the scraper 3 can be made of Q235 carbon structural steel plate, NM360 wear-resistant plate, Q345B steel plate, thickened manganese steel or ultra-high molecular weight polyethylene.

[0047] Q235 carbon structural steel plate has good processability and low price.

[0048] NM360 wear-resistant plate is a kind of steel plate material with high strength and good wear resistance. The scraper made of NM360 wear-resistant plate can effectively increase the service life of the scraper coal feeder, especially suitable for occasions that need to withstand high-intensity wear.

[0049] Q345B steel plate is a low-alloy high-strength steel plate with the characteristics of high strength, good toughness and excellent wear resistance, which can meet the high requirements for scraper strength and wear resistance.

[0050] Thickened manganese steel has excellent tensile strength and wear resistance. The scraper made of thickened manganese steel has a long service life.

[0051] Ultra-high molecular weight polyethylene not only has good wear resistance and is not easy to deform or break, but is also corrosion-resistant and self-lubricating. It can reduce friction between mechanical parts, reduce energy consumption, and improve transportation efficiency.

[0052] When selecting the scraper material, multiple factors can be considered according to actual conditions, including the working conditions of the scraper coal feeder, material properties, service life requirements and cost.

[0053] Preferably, the coal feed comb 2, the scraper 3, the scraper outer guard plate 4 and the bottom plate are made of the same raw materials.

[0054] This embodiment provides a multi-channel long chain scraper coal feeder, and its working method is as follows: Coal particles fall into the scraper coal feeder from the coal feeding port 1, and the coal seam thickness is raked evenly by the coal feeding comb 2. Driven by the scraper 3, the coal particles move from the head end to the end. Finally, the scraper 3 brings the coal particles to the coal dropping port 5 and falls into the furnace.

[0055] Example 4 Reference Figure 3 The present embodiment provides a coal feeding comb 2, comprising a bracket 21 and a plurality of comb teeth 22, all of which are evenly arranged. The two ends of the bracket 21 are respectively mounted on two scraper outer guard plates 4 on the outer periphery of the coal feeder, and the lower end of the bracket 21 is fixedly connected to the plurality of comb teeth 22.

[0056] Preferably, the lower end of the comb teeth 22 may be flat, pointed, or hemispherical.

[0057] Example 5 This embodiment provides a coal feeding system, including a multi-channel long-chain scraper coal feeder provided in Embodiment 1 or 2.

[0058] Example 6 This embodiment provides a coal feeding method, comprising the following steps: Step S1, coal particles fall into the scraper coal feeder from the coal feeding port 1; Step S2, the coal feeding comb 2 raks the uneven thickness of the coal seam and moves from front to back driven by the scraper 3; Step S3: The scraper 3 brings the coal particles into different flow channels and to the coal drop port 5, where the coal particles fall into the furnace.

[0059] The term "consisting of" describing a combination shall include the identified elements, ingredients, parts or steps and other elements, ingredients, parts or steps that do not substantially affect the basic novel characteristics of the combination. The use of the terms "comprising" or "including" to describe a combination of elements, ingredients, parts or steps herein also contemplates embodiments that consist essentially of these elements, ingredients, parts or steps. By using the term "may", it is intended to illustrate that any of the attributes described that "may" be included are optional.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0061] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the foregoing claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A multi-channel long chain scraper coal feeder, characterized in that: It comprises a coal feeding comb (2), a scraper (3), a coal drop port (5), a scraper machine diverter plate (7) and a bottom plate; A coal feeding port (1) is located above the front end of the bottom plate. A coal feeding comb (2) and a scraper (3) are arranged behind the coal feeding port (1) along the coal transportation direction. The coal feeding comb (2) is located above the scraper (3) and close to the coal feeding port (1). A coal drop port (5) is provided on the bottom plate. A plurality of scraper diverter plates (7) are fixed on the bottom plate. The number of the scraper diverter plates (7) is one less than the number of the coal drop ports (5).

2. A multi-channel long chain scraper coal feeder according to claim 1, characterized in that: The bottom plate is a stepped structure.

3. The multi-channel long chain scraper coal feeder according to claim 1, characterized in that: A scraper outer guard plate (4) is arranged on the outer periphery of the bottom plate.

4. The multi-channel long chain scraper coal feeder according to claim 1, characterized in that: The scraper coal feeder is provided with multiple layers of coal feeding combs (2) arranged in staggered rows.

5. A multi-channel long chain scraper coal feeder according to claim 1 or 4, characterized in that: The coal feeding comb (2) comprises a bracket (21), and a plurality of comb teeth (22) are fixedly connected to the lower end of the bracket (21).

6. The multi-channel long chain scraper coal feeder according to claim 1, characterized in that: The distance between adjacent comb teeth (22) is less than half of the flow channel width.

7. The multi-channel long chain scraper coal feeder according to claim 1, characterized in that: The coal feeding comb (2) is perpendicular to the coal transportation direction, and the scraper conveyor diverter plate (7) is arranged along the coal transportation direction.

8. The multi-channel long chain scraper coal feeder according to claim 1, characterized in that: The coal drop port (5) is located behind the scraper (3).

9. The multi-channel long chain scraper coal feeder according to claim 1, characterized in that: The scraper (3) is driven by a motor.

10. A coal feeding system, characterized in that: It includes the multi-channel long chain scraper coal feeder as described in claim 1.

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