A feeding mechanism for a biomass circulating fluidized bed boiler

Abstract

This utility model relates to the field of biomass boiler technology, specifically a feeding mechanism for a biomass circulating fluidized bed boiler. It includes a biomass feeding assembly, a slag feeding assembly, a mixing section, and a feeding section. The biomass feeding assembly adopts a horizontal spiral extrusion structure. The mixing section is vertically arranged and located at the end of the biomass feeding assembly. The slag feeding assembly connects to the mixing section from the opposite side. The mixing section is equipped with a mixing motor and agitators. The feeding section is connected to the bottom of the mixing section and is equipped with a spiral feeder. This utility model, through the coordinated operation of the biomass feeding assembly, slag feeding assembly, mixing section, and feeding section, achieves uniform mixing and stable feeding of biomass fuel and slag. It can effectively solve problems such as insufficient circulating material, ash accumulation, and corrosion during biomass combustion, improving combustion efficiency and fuel utilization, and ensuring the efficient and stable operation of the boiler.

Description

Technical Field

[0001] This utility model relates to the field of biomass boiler technology, specifically a feeding mechanism for a biomass circulating fluidized bed boiler. Background Technology

[0002] A biomass circulating fluidized bed (CFB) boiler is a high-efficiency thermal energy device that burns biomass fuels (such as straw, sawdust, and rice husks) using circulating fluidized bed (CFB) technology. Its core combines the high-efficiency combustion characteristics of a circulating fluidized bed with the renewability of biomass, achieving complete fuel combustion and efficient energy conversion through a closed-loop system of "fluidized combustion - gas-solid separation - ash and slag recycling." Biomass fuels are generally characterized by high moisture content and low calorific value, making ignition and complete combustion relatively difficult. However, circulating fluidized bed filtration features large heat storage capacity and a high circulation ratio, thus ensuring normal combustion even when the biomass moisture content is as high as 50-60%.

[0003] However, circulating fluidized bed boilers also have certain problems in burning biomass. Due to the high volatile matter and low ash content of biomass fuel, insufficient circulating material can easily occur in the boiler itself. Furthermore, the high content of alkali metals and chlorine in biomass easily leads to ash accumulation and blockage, causing high-temperature and low-temperature corrosion of the heating surfaces. A better technical solution to these problems is to mix coal slag or ash from coal-fired circulating fluidized bed boilers into the biomass fuel. The ash can increase the ash content in the boiler and increase the circulating material within the circulating fluidized bed boiler. In addition, the inert nature of the ash can inhibit the sintering of alkali metals and the corrosion problems caused by chlorine. Utility Model Content

[0004] This utility model aims to provide a feeding mechanism for a biomass circulating fluidized bed boiler. By mixing biomass fuel and slag evenly in proportion during the feeding stage, it ensures sufficient circulating material in the biomass circulating fluidized bed boiler while reducing slagging and corrosion problems in the boiler.

[0005] To solve the above-mentioned technical problems, the technical solution provided by this utility model is as follows: A feeding mechanism for a biomass circulating fluidized bed boiler includes a biomass feeding assembly, a slag feeding assembly, a mixing section, and a feeding section; The biomass feeding assembly adopts a horizontal spiral feeding structure, the mixing section is vertically arranged and located at the end of the biomass feeding assembly, the slag feeding assembly is connected to the mixing section from the opposite side, and the mixing section is equipped with a mixing motor and a stirrer. The feeding section is connected to the bottom of the mixing section, and the feeding section is equipped with a spiral feeder.

[0006] As an improvement, the biomass feeding assembly includes a feeding channel with a biomass inlet at the top. The feeding channel contains a rotating shaft and a spiral pusher plate mounted on the rotating shaft. A first motor that drives the rotating shaft to rotate is provided on one side of the feeding channel.

[0007] As an improvement, the stirrer includes a stirring shaft and stirring rods. One end of the stirring shaft is connected to the output shaft of the mixing motor, and the other end extends to the lower section of the mixing section. There are multiple stirring rods, which are evenly distributed at the end of the stirring shaft.

[0008] As an improvement, the slag feeding assembly includes a feed pipe and a slag inlet, and the feed pipe is equipped with a solenoid valve; The mixing section has a slag inlet on its side wall, which is located below the biomass feeding assembly and above the stirring rod.

[0009] As an improvement, the spiral feeder includes a second motor and a second rotating shaft, with a second spiral pusher plate mounted on the second rotating shaft.

[0010] As an improvement, the inner wall of the mixing section is provided with a wear-resistant coating, the thickness of which is 1-3 mm.

[0011] The advantages of this utility model are: 1. This utility model achieves uniform mixing and stable feeding of biomass fuel and slag through the coordinated operation of the biomass feeding component, slag feeding component, mixing section and feeding section. It can effectively solve problems such as insufficient circulating material, slagging and corrosion in the biomass combustion process, improve combustion efficiency and fuel utilization, and ensure the efficient and stable operation of the boiler.

[0012] 2. In this invention, the biomass feeding assembly adopts a spiral feeding structure, which can effectively handle fuels with high moisture content, prevent blockage of the feeding channel, and ensure smooth feeding. By adjusting the speed of the first motor, the pushing speed can be precisely controlled to meet the needs of different combustion conditions. The slag feeding assembly is equipped with a solenoid valve, which can precisely control the slag feeding amount and optimize the mixing ratio. The mixing section can fully crush and mix the biomass fuel and slag evenly. The spiral feeder in the feeding section further ensures the uniform and continuous conveying of the mixed materials, avoids material accumulation or interruption in the combustion chamber, and maintains the stability of the combustion process. Attached Figure Description

[0013] Figure 1 This is a structural diagram of the feeding mechanism of a biomass circulating fluidized bed boiler in Example 1.

[0014] Figure 2 This is an internal structural diagram of the biomass feeding component in the feeding mechanism of a biomass circulating fluidized bed boiler in Example 1.

[0015] Figure 3 This is an internal structural diagram of the slag feeding component in the feeding mechanism of a biomass circulating fluidized bed boiler in Example 1.

[0016] Figure 4 This is a structural diagram of the screw feeder in the feeding mechanism of a biomass circulating fluidized bed boiler in Example 1.

[0017] The image shows: 1-Biomass feeding assembly, 11-Feeding channel, 12-Biomass inlet, 13-Rotating shaft, 14-Spiral pusher plate, 15-First motor, 2-Slag feeding assembly, 21-Feeding pipe, 22-Slag inlet, 23-Solenoid valve, 3-Mixing section, 31-Slag inlet, 4-Feeding section, 5-Mixing motor, 6-Agitator, 61-Agitating shaft, 62-Agitating rod, 7-Spiral feeder, 71-Second motor, 72-Second rotating shaft, 73-Second spiral pusher plate. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0019] Example 1 This embodiment discloses a feeding mechanism for a biomass circulating fluidized bed boiler, including a biomass feeding assembly 1, a slag feeding assembly 2, a mixing section 3, and a feeding section 4.

[0020] The biomass feeding assembly 1 adopts a horizontal spiral feeding structure. The mixing section 3 is vertically arranged and located at the end of the biomass feeding assembly 1. The slag feeding assembly 2 is connected to the mixing section 3 from the opposite side. The mixing section 3 is equipped with a mixing motor 5 and an agitator 6. The feeding section 4 is connected to the bottom of the mixing section 3 and is equipped with a spiral feeder 7.

[0021] The biomass feeding assembly 1 includes a feeding channel 11, a biomass inlet 12 at the top of the feeding channel 11, a rotating shaft 13 and a spiral pusher plate 14 mounted on the rotating shaft 13 inside the feeding channel 11, and a first motor 15 on one side of the feeding channel 11 to drive the rotating shaft 13 to rotate. The biomass circulating fluidized bed boiler can handle biomass fuel with high moisture content. This embodiment adopts a spiral feeding structure. When the rotating shaft 13 rotates, the spiral pusher plate 14 can uniformly and continuously push the biomass fuel to the mixing section 3, ensuring the stability of the feed. The spiral feeding structure is suitable for handling biomass fuel with high moisture content, effectively preventing the fuel from sticking or clogging the feeding channel 11 due to excessive moisture during the feeding process, thus ensuring smooth feeding. Simultaneously, by controlling the rotation speed of the first motor 15, the pushing speed of the spiral pusher plate 14 can be controlled, improving the accuracy of feeding.

[0022] The stirrer 6 includes a stirring shaft 61 and stirring rods 62. One end of the stirring shaft 61 is connected to the output shaft of the mixing motor 5, and the other end extends to the lower section of the mixing section 3. There are multiple stirring rods 62, which are evenly distributed at the end of the stirring shaft 61.

[0023] The slag feeding assembly 2 includes a feed pipe 21 and a slag inlet 22. The feed pipe 21 is equipped with a solenoid valve 23. The mixing section 3 has a slag inlet 31 on its side wall. The slag inlet 31 is located below the biomass feeding assembly 1 and above the stirring rod 62.

[0024] Biomass fuel and slag enter the mixing section 3 from both sides, where they are crushed and mixed by the stirring rod 62, ensuring a uniform mixture before entering the feeding section 4. The feeding section 4 is equipped with a screw feeder 7. The screw feeder 7 includes a second motor 71 and a second rotating shaft 72, with a second screw pusher plate 73 mounted on the second rotating shaft 72. The screw feeder 7 further ensures that the mixed material enters the boiler combustion chamber uniformly and continuously, preventing material accumulation or flow interruption, thus guaranteeing the stability of the combustion process. By precisely controlling the speed of the second motor 71, the feeding speed can be adjusted to adapt to different combustion conditions, further improving combustion efficiency and fuel utilization.

[0025] The inner wall of mixing section 3 is coated with a wear-resistant coating with a thickness of 1-3 mm. Since mixing section 3 is the main location for mixing biomass fuel and slag, the friction and impact of the materials are relatively frequent. The wear-resistant coating can effectively resist the wear of the materials on the inner wall, reduce the downtime for equipment maintenance, and improve the operational reliability of the equipment. It is especially suitable for long-term continuous operation.

[0026] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.

Claims

1. A biomass circulating fluidized bed boiler feeding mechanism, characterized by, This includes a biomass feeding assembly, a slag feeding assembly, a mixing section, and a feeding section; The biomass feeding assembly adopts a horizontal spiral feeding structure, the mixing section is vertically arranged and located at the end of the biomass feeding assembly, the slag feeding assembly is connected to the mixing section from the opposite side, and the mixing section is equipped with a mixing motor and a stirrer. The feeding section is connected to the bottom of the mixing section, and the feeding section is equipped with a spiral feeder.

2. The feeding mechanism for a biomass circulating fluidized bed boiler according to claim 1, characterized in that, The biomass feeding assembly includes a feeding channel with a biomass inlet at the top. The feeding channel contains a rotating shaft and a spiral pusher plate mounted on the rotating shaft. A first motor that drives the rotating shaft to rotate is located on one side of the feeding channel.

3. The biomass circulating fluidized bed boiler feeding mechanism according to claim 1, wherein, The stirrer includes a stirring shaft and stirring rods. One end of the stirring shaft is connected to the output shaft of the mixing motor, and the other end extends to the lower section of the mixing section. There are multiple stirring rods, which are evenly distributed at the end of the stirring shaft.

4. A biomass circulating fluidized bed boiler feeding mechanism according to claim 3, characterized in that, The slag feeding assembly includes a feed pipe and a slag inlet, and the feed pipe is equipped with a solenoid valve; The mixing section has a slag inlet on its side wall, which is located below the biomass feeding assembly and above the stirring rod.

5. The biomass circulating fluidized bed boiler feeding mechanism according to claim 1, wherein, The spiral feeder includes a second motor and a second rotating shaft, and a second spiral pusher plate is provided on the second rotating shaft.

6. The biomass circulating fluidized bed boiler feeding mechanism according to claim 1, wherein, The inner wall of the mixing section is provided with a wear-resistant coating, the thickness of which is 1-3 mm.

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