A drying system for drying lignite
Patent Information
- Application Number
- CN202620028997.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2025-09-29
- Filing Date
- 2026-01-12
- Publication Date
- 2026-10-20
- Estimated Expiration
- 2036-01-12
AI Technical Summary
但是，上述这些设备的设计不同，其复杂的内部结构和有限的传热方式，导致了烘干效率差距较大
1、高效烘干：通过设置扬料板，使褐煤在筒体内形成均匀料幕，极大地增加了褐煤与逆流热烟气的接触面积与换热效率，在约 30 分钟的交换时间内，实现高效烘干，提升了整体生产效率；
Smart Images
Figure CN224872810U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of lignite drying technology, specifically relating to a drying system for lignite drying. Background Technology
[0002] Existing lignite drying equipment mainly includes rotary lignite dryers, belt furnace dryers, and single-layer drum dryers. Rotary lignite dryers, with their unique drum rotation mechanism, ensure comprehensive and deep contact between the lignite and the heat medium, effectively completing the drying process. Belt furnace dryers use the continuous movement of a conveyor belt to smoothly feed the lignite into the heating furnace, utilizing the flow of hot air to efficiently remove moisture from the lignite. Single-layer drum dryers, through the rotation of the drum and the ingenious design of the internal lifting plates, allow the lignite to continuously tumble within the drum, achieving thorough heat exchange with the hot gas. However, the different designs of these devices, their complex internal structures, and limited heat transfer methods result in significant differences in drying efficiency. The large energy consumption and extended production time highlight the shortcomings in energy saving and efficiency. Furthermore, during the drying process, the volatile substances released by lignite are highly flammable under high temperatures, posing a significant safety hazard—aroma. Therefore, improving drying efficiency and ensuring production safety have become urgent technical challenges for lignite drying equipment. Summary of the Invention
[0003] The purpose of this invention is to address the shortcomings of the existing technology and provide a lignite drying system that can improve drying efficiency and ensure production safety, shorten drying time, ensure the stability of the drying process through temperature control, enhance safety performance, and save energy and protect the environment.
[0004] To achieve the above objectives, this utility model provides the following technical solution: a drying system for drying lignite, comprising a raw material silo, a cylinder, a fluidized bed furnace, a belt conveyor, a cyclone dust collector, a blower, a dry powder settling chamber, a spray tower, and a settling tank; The cylinder is inclined and fixed by a roller support structure; the raw material silo is located above the cylinder and is connected to the cylinder by a closed belt conveyor; the fluidized bed furnace is located near the upper end of the cylinder, and the hot flue gas outlet of the fluidized bed furnace is connected to the cylinder; a discharge valve is installed at the bottom of the cylinder; a belt conveyor is installed below the discharge valve. The dust outlet at the bottom of the cylinder is connected to a cyclone dust collector located near the cylinder via a pipe; the dust-laden gas inlet of the cyclone dust collector is connected to a fan located nearby; the fan outlet is connected to a dry powder settling chamber via a pipe, and the dry powder settling chamber is connected to a spray tower located in the settling tank.
[0005] As a further optimization of this utility model, a transmission device is provided on the cylinder; the transmission device includes a large gear ring, a small gear, a motor, and a reducer connected to the motor; the large gear ring is fixed on the cylinder, the small gear is connected to the output shaft of the reducer, and the small gear meshes with the large gear ring. As a further optimization of this utility model, lifting plates are installed alternately along the circumferential direction on the inner wall of the cylinder.
[0006] As a further optimization of this utility model, temperature sensors are installed inside the cylinder and at the hot flue gas outlet of the fluidized bed furnace.
[0007] As a further optimization of this utility model, the system is also equipped with a controller, which is connected to the temperature sensor signals inside the cylinder and at the hot flue gas outlet of the fluidized bed furnace.
[0008] As a further optimization of this utility model, a powder conveyor is provided below the cyclone dust collector.
[0009] The beneficial effects of this utility model are as follows: 1. High-efficiency drying: By setting up lifting plates, the lignite forms a uniform material curtain in the cylinder, which greatly increases the contact area and heat exchange efficiency between the lignite and the countercurrent hot flue gas. High-efficiency drying is achieved in about 30 minutes, improving the overall production efficiency. 2. Precise temperature control and safety assurance: By combining temperature sensors and controllers, the drying temperature is stably controlled at 180-200℃. This temperature is lower than the ignition point of lignite (350℃), avoiding the risk of lignite combustion and ensuring production safety. At the same time, this temperature range effectively promotes the decomposition of hydroxyl functional groups in lignite, removes bound water, and improves its quality. It also prevents the precipitation of coal tar at temperatures above 200℃, reducing equipment adhesion and subsequent waste gas treatment load. 3. Stable quality improvement effect: During the drying process, the decomposition of hydroxyl functional groups in lignite and the collapse of capillary pores occur simultaneously. Each 1% removal of moisture content corresponds to an increase in calorific value of approximately 150 kcal / kg. Stable quality improvement effect is achieved with moisture content ≤15% and calorific value ≥4500 kcal / kg, thereby improving the quality and economic value of lignite. 4. Environmental protection and energy saving: The drying heat source adopts a biomass fuel fluidized bed furnace. The sulfur content of biomass fuel is <0.1%, and the nitrogen oxide generation during combustion is reduced by 60% compared with coal. Carbon emissions per unit capacity are reduced by more than 40%, and the fuel cost is 15-20% lower than that of coal. By generating hot flue gas through combustion to provide heat for drying, economic and environmental benefits are synergistically achieved. 5. Excellent dust control: Two cyclone dust collectors are equipped at the end of the cylinder, which use centrifugal force to efficiently separate large dust particles (≥10μm) with a dust removal efficiency of 65%. The collected dust is discharged into the product conveying system through the bottom outlet, reducing dust emissions, thus recycling resources and protecting the environment. 6. Reasonable waste gas treatment: The drying waste gas and combustion waste gas are successively treated by a three-stage dust removal process: cyclone dust collector, dry powder settling chamber and spray tower. Each stage works closely together to effectively remove dust of different particle sizes and a small amount of phenolic compounds. The spray wastewater is recycled after sedimentation in a three-stage sedimentation tank and is cleaned regularly. Attached Figure Description
[0010] Figure 1 This is a schematic diagram of the present invention; Figure 2 This diagram shows the connection relationship between the cylinder and the transmission device. Figure 3 This is a process flow diagram of the present invention. Detailed Implementation
[0011] Embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the present invention. Where specific techniques, connections, or conditions are not specified in the embodiments, they are performed in accordance with the techniques, connections, or conditions described in the literature in the field or according to the product instructions. Materials, instruments, or equipment used without specified manufacturers are all conventional products that can be obtained through purchase.
[0012] like Figure 1 and Figure 2 As shown, the present invention provides a drying system for drying lignite, including a raw material silo 1, a cylinder 2, a fluidized bed furnace 3, a belt conveyor 4, a cyclone dust collector 5, a blower 6, a dry powder settling chamber 7, a spray tower 8, and a settling tank 9. The cylinder 2 is installed at an angle and fixed by the roller support structure 13, such as Figure 1As shown; the cylinder 2 is rotatably connected to the roller support structure 13; the raw material silo 1 is located above the cylinder 2 and is connected to the cylinder 2 via a closed belt conveyor 10; the closed belt conveyor is responsible for uniformly and stably conveying the pre-treated lignite material from the raw material silo into the cylinder; the raw material silo 1 is equipped with a feeder, which can accurately control the feeding speed and flow rate to ensure the continuity and stability of the drying process; the fluidized bed furnace 3 is located near the upper end of the cylinder 2, and the biomass hot flue gas outlet of the fluidized bed furnace 3 is connected to the cylinder 2; a star-shaped discharge valve 11 is provided at the bottom of the cylinder 2; the discharge valve smoothly discharges the dried lignite material from the cylinder, and at the same time, with a good sealing structure, it effectively prevents hot air and dust from leaking out from the discharge port, maintains the pressure stability inside the drying system, and reduces heat loss and environmental pollution; a belt conveyor 4 is provided below the discharge valve 11 to transport the dried lignite material; The dust outlet at the bottom of the cylinder 2 is connected to the cyclone dust collector 5 located near the cylinder 2 via a pipe; the dust-laden gas inlet of the cyclone dust collector 5 is connected to the fan 6 located nearby; the outlet of the fan 6 is connected to the dry powder settling chamber 7 via a pipe, and the dry powder settling chamber 7 is connected to the spray tower 8 located in the settling tank 9; a powder conveyor 12 is provided below the cyclone dust collector 5.
[0013] The fluidized bed furnace 3 in this invention is a biomass fuel fluidized bed furnace. This equipment uses biomass such as straw and sawdust as fuel, with a sulfur content of <0.1%. During combustion, the amount of nitrogen oxides generated is significantly reduced by 60% compared to coal, and carbon emissions per unit capacity are reduced by more than 40%, while the fuel cost is 15-20% lower than that of coal. The fuel is transported from the fuel bin to the furnace via a screw feeder and belt conveyor. Two high-pressure blowers per furnace provide fluidizing air, enabling the fuel to burn efficiently in a fluidized bed. The generated hot flue gas, with a temperature of approximately 600-800℃, is introduced into the rotary drum dryer by an induced draft fan, providing sufficient heat for drying lignite.
[0014] In this invention, an induced draft system consisting of a cyclone dust collector 5 and a fan 6 can promptly discharge the moisture and waste gas generated during the drying process inside the cylinder, maintaining a stable airflow balance within the cylinder and ensuring the smooth progress of the drying process. By reasonably adjusting the airflow and air pressure of the induced draft system, the drying speed and drying effect can be effectively controlled.
[0015] This invention incorporates multiple dust removal devices to achieve multi-stage dust removal. The cyclone dust collector utilizes centrifugal force to efficiently separate large dust particles ≥10μm, achieving a dust removal efficiency of up to 65%. The dry powder settling chamber relies on gravity settling to remove particles larger than 50μm, further reducing dust concentration. The spray tower removes fine particulate matter ≥1μm and a small amount of phenolic compounds through water film and spray washing, achieving deep purification of the exhaust gas and ensuring that the final exhaust gas meets environmental protection standards.
[0016] As a further implementation of this scheme, a transmission device is provided on the cylinder 2, making the cylinder 2 a rotatable structure. The transmission device includes a large gear ring 21, a small gear 22, a motor 23, and a reducer 24 connected to the motor 23. The large gear ring 21 is fixed on the cylinder 2, and the small gear 22 is connected to the output shaft of the reducer 24, with the small gear 22 meshing with the large gear ring 21. The motor outputs power, which is reduced in speed by the reducer, driving the small gear to rotate. The small gear meshes with the large gear ring fixed on the cylinder, thereby driving the cylinder to rotate slowly at a suitable speed, ensuring that the lignite inside the cylinder can be continuously and stably dried. As a further implementation of this scheme, lifting plates 25 are staggered along the circumference of the inner wall of the cylinder 2. During the rotation of the cylinder, the lifting plates 25 lift and evenly distribute the lignite, forming a material curtain, which greatly increases the contact area between the lignite and the hot flue gas, and enhances the heat exchange efficiency. The cylinder 2 is made of rolled and welded steel plate and is cylindrical. The cylinder has a certain inclination angle, which allows the material to move smoothly from the feed end to the discharge end under the action of gravity.
[0017] As a further implementation of this scheme, temperature sensors are installed inside the cylinder 2 and at the biomass hot flue gas outlet of the fluidized bed furnace 3 to monitor the temperature inside the cylinder and the hot flue gas in real time during the drying process.
[0018] The system is also equipped with a controller, which is connected to temperature sensors inside the cylinder 2 and at the biomass hot flue gas outlet of the fluidized bed furnace 3. The temperature sensors feed back the temperature signals to the controller. Of course, in this invention, the fuel for the fluidized bed furnace 3 is supplied through existing conveying equipment (screw feeder and belt conveyor). The controller is also connected to the conveying equipment to adjust the fuel supply of the fluidized bed furnace in a coordinated manner, ensuring that the drying temperature is stably controlled at 180-200℃. This ensures efficient drying and lignite upgrading, while avoiding problems such as lignite combustion or coal tar precipitation caused by excessively high temperatures.
[0019] After drying, the lignite is conveyed to the product warehouse via a closed conveyor belt, reducing material loss and environmental pollution during transportation. The equipment employs a robust sealing structure at the feeding and discharging points to ensure the drying process is conducted under negative pressure (system negative pressure -500Pa to -300Pa), preventing heat and dust leakage and ensuring a safe and clean production environment.
[0020] Figure 3In the process flow diagram shown, lignite is sequentially fed into the raw material silo (equipped with a pulse bag filter) via a crusher, cyclone collector, and bucket elevator. The raw material is then fed into the rotary drum dryer (i.e., the drum body) via a feed hopper (with a gas collection hood and bag filter), and a fluidized bed furnace provides biomass heat flue gas. The drying and combustion exhaust gases sequentially pass through a cyclone dust collector, a small gravity dust collector (No. 1), a large gravity dust collector (No. 2) (with waste heat recovery), an induced draft fan, and a four-stage spray tower. Wastewater is circulated into a seven-stage sedimentation tank and, after purification, is discharged through an 18m exhaust stack. The drum discharge material is conveyed to the product workshop via a product conveyor, and the powder collected by the cyclone is pneumatically conveyed to the powder silo before being loaded onto trucks for sale.
[0021] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and inventive concept of the present utility model, should be included within the protection scope of the present utility model.
Claims
1. A drying system for drying lignite, characterized in that, It includes a raw material silo (1), a cylinder (2), a fluidized bed furnace (3), a belt conveyor (4), a cyclone dust collector (5), a blower (6), a dry powder settling chamber (7), a spray tower (8), and a settling tank (9); The cylinder (2) is inclined and fixed by a roller support structure (13); the raw material silo (1) is located above the cylinder (2) and is connected to the cylinder (2) by a closed belt conveyor (10); the fluidized bed furnace (3) is set near the upper end of the cylinder (2) and its hot flue gas outlet is connected to the cylinder (2); a discharge valve (11) is set at the bottom of the cylinder (2); a belt conveyor (4) is set below the discharge valve (11); The dust outlet at the bottom of the cylinder (2) is connected to a cyclone dust collector (5) located near the cylinder (2) via a pipe; the dust-laden gas inlet of the cyclone dust collector (5) is connected to a fan (6) located nearby; the outlet of the fan (6) is connected to a dry powder settling chamber (7) via a pipe, and the dry powder settling chamber (7) is connected to a spray tower (8) located in the settling tank (9).
2. The drying system for lignite drying according to claim 1, characterized in that, A transmission device is provided on the cylinder (2); the transmission device includes a large gear ring (21), a small gear (22), a motor (23) and a reducer (24) connected to the motor (23); the large gear ring (21) is fixed on the cylinder (2), the small gear (22) is connected to the output shaft of the reducer (24), and the small gear (22) meshes with the large gear ring (21).
3. A drying system for lignite drying according to claim 2, characterized in that, The inner wall of the cylinder (2) is equipped with lifting plates (25) in a staggered manner along the circumferential direction.
4. A drying system for lignite drying according to claim 1, characterized in that, Temperature sensors are installed inside the cylinder (2) and at the hot flue gas outlet of the fluidized bed furnace (3).
5. A drying system for lignite drying according to claim 4, characterized in that, The system is also equipped with a controller, which is connected to the temperature sensor signals inside the cylinder (2) and at the hot flue gas outlet of the boiling furnace (3).
6. A drying system for lignite drying according to claim 1, characterized in that, A powder conveyor (12) is installed below the cyclone dust collector (5).