A mobile bed fluidized dryer

Abstract

The utility model discloses a kind of high-efficiency moving bed type flow state drying machine, including shell, transmission mechanism and drying mechanism;Drying mechanism includes hot flue gas chamber and at least two drying conveyors and grate plate arranged at the bottom of shell, at least two drying conveyors are spaced apart in the shell along the vertical direction of shell, and the discharge end of upper drying conveyor is corresponded with the feeding area of lower drying conveyor through material passage;Grate plate is respectively arranged along drying conveyor in shell, the grate plate is provided with through hole for hot flue gas, and the drying conveyor includes transmission chain plate and squeegee extending to grate plate;Transmission mechanism drives transmission chain plate to move to carry material along the surface of grate plate to move;Shell top is equipped with air outlet, and one end of uppermost drying conveyor in shell top is equipped with feeding port, and the end of lowermost drying mechanism away from feeding port in shell side is equipped with discharge port, and hot flue gas chamber is equipped with air inlet.

Description

Technical Field

[0001] This invention relates to the field of drying, and more specifically to a moving bed fluidized bed dryer. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] Currently, the most commonly used drying equipment in industry is the rotary dryer. A rotary dryer consists of a rotating long cylinder, lifting plates on the inner wall of the cylinder, and inlet and outlet hoods. Under the combined action of the rotating cylinder and the lifting plates, the material is continuously lifted and scattered. Hot airflow, drawn by a fan, passes through the cylinder, making extensive contact and heat exchange with the scattered material, thus drying it. However, due to limitations in the number and structure of the lifting plates, the material cannot form a uniform curtain across the cylinder's cross-section, resulting in insufficient contact and heat exchange between the hot airflow and the material. Furthermore, the dynamic seal between the inlet / outlet hood and the rotating cylinder is difficult to ensure, leading to significant air leakage and consequently, the thermal efficiency of the rotary dryer is not high, typically between 50% and 60%. Additionally, the large size and weight of rotary dryers are also significant weaknesses.

[0004] Existing moving bed dryers that use single-layer drying often suffer from incomplete drying due to uneven material layer thickness and insufficient heat exchange as airflow passes through the material layer. If the residence time is extended to ensure drying effect, the bed length needs to be significantly increased, resulting in a large equipment footprint, low space utilization, and difficulty in adapting to the compact layout requirements of industrial scenarios. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this utility model provides a high-efficiency moving bed fluidized bed dryer.

[0006] A high-efficiency moving bed fluidized bed dryer includes a shell, a transmission mechanism, and a drying mechanism. The drying mechanism includes a hot flue gas chamber located at the bottom of the shell and at least two drying conveyor belts. The at least two drying conveyor belts are arranged vertically within the shell at intervals. A material channel is provided between adjacent drying conveyor belts. The discharge end of the upper drying conveyor belt corresponds to the feed area of ​​the lower drying conveyor belt through the material channel. The shell is provided with grates along the drying conveyor belts. Each grate has a through hole for hot flue gas to pass through. The drying conveyor belts include a drive chain and scrapers extending towards the grate. Hot air flows from bottom to top through the grate and the material. The material is used for two purposes: firstly, to heat the material and evaporate moisture; secondly, the material is blown up by the wind to a boiling state, which promotes the material's forward movement. The material is mainly driven forward by the scraper, so it is highly adaptable to the materials it processes. It can dry block or granular materials, and even if the particle size distribution is not very uniform, it will not affect normal operation. The transmission mechanism drives the transmission chain plate to move, thereby moving the material along the surface of the grate plate. The top of the shell is provided with an air outlet, and the top of the shell is provided with a feed inlet at one end corresponding to the uppermost drying conveyor belt. The side of the shell is provided with a discharge outlet at the end of the lowermost drying mechanism away from the feed inlet. The hot flue gas chamber is provided with an air inlet.

[0007] In some embodiments, the through hole has an inverted conical structure, making the grate hole less prone to clogging.

[0008] In some embodiments, the through holes of the grate are elongated and arranged at an angle, with adjacent rows of through holes staggered. Each through hole forms a preset angle with the length direction of the grate, and the angle ranges from 10° to 45°.

[0009] In some embodiments, the through holes of the grate plate adopt a wind cap structure, which is elongated and tapered at both ends. This allows hot gas to pass through while ensuring the grate plate does not leak material. The wind cap structure facilitates the passage of the scraper's teeth, and the wind cap has a certain turning effect on the material as it moves on the grate plate.

[0010] In some embodiments, the material channels are equipped with flap valves. This prevents lower-level airflow from directly entering the upper level through the pipe, causing airflow short-circuiting, and allows the hot airflow to undergo multiple heat exchanges, effectively improving thermal efficiency.

[0011] In some embodiments, the scraper has a flat or serrated structure. This can be adjusted according to the type of material to be dried.

[0012] In some embodiments, side baffles are provided on both sides of the grate. This ensures that all material is scraped away by the scraper and prevents a small amount of material from remaining for an extended period.

[0013] In some embodiments, the drying conveyor belt is inclined, and the grates are arranged in a stepped manner to cooperate with the drying conveyor belt. There is partial overlap between the grates to reduce material leakage.

[0014] In some embodiments, the transmission mechanism is a speed-regulating motor.

[0015] Advantages of this invention compared to existing technologies:

[0016] Because the gas passes directly through the material layer, the heat exchange between the gas and solid occurs in a near-fluidized state, which determines the high thermal efficiency of this dryer. The transmission mechanism is driven by a speed-regulating motor, allowing the scraper speed to be adjusted within a wide range. The residence time of the material within the dryer can be adjusted as needed to ensure acceptable moisture content at the discharge. The high opening ratio of the grate plate (10%–20%) significantly improves the dryer's volumetric efficiency, resulting in a much smaller size while maintaining the same output and evaporation rate. A double-layer structure further enhances heat utilization and increases the material's residence time on the bed surface.

[0017] Multi-layer drying conveyor belts allow materials to flow vertically layer by layer, significantly extending the material residence time without increasing the equipment footprint, adapting to drying needs, and avoiding the problem of incomplete drying caused by the length limitation of single-layer structures; at the same time, the through holes designed for materials with higher moisture content in the upper layer allow for sufficient heat exchange between hot flue gas and materials in each layer, improving heat utilization. Attached Figure Description

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Figure 2 This is a schematic diagram of the scraper structure of this utility model.

[0021] Figure 3 This is a schematic diagram of the grate plate structure and grate hole structure of this utility model.

[0022] Figure 4 This is a schematic diagram of the cross-section of the drying conveyor belt in Embodiment 1 of this utility model.

[0023] Figure 5 This is a top view of the grate plate in Embodiment 1 of this utility model.

[0024] Figure 6 This is a schematic diagram of the cross-section of the drying conveyor belt in Embodiment 2 of this utility model.

[0025] Figure 7This is a top view of the grate plate in Embodiment 2 of this utility model.

[0026] Figure 8 This is a partial cross-sectional view of the grate plate in Embodiment 2 of this utility model.

[0027] The reference numerals in the attached drawings are as follows: 1-shell; 2-hot flue gas chamber; 3-drying conveyor belt; 4-material channel; 5-grate; 6-transmission chain plate; 7-through hole; 8-scraper; 9-air inlet; 10-air outlet; 11-feed inlet; 12-discharge outlet; 13-side baffle; 14-transmission mechanism; 15-flip valve; 16-wind cap. Detailed Implementation

[0028] Example 1:

[0029] like Figure 1-5 As shown: A high-efficiency moving bed fluidized bed dryer includes a shell 1, a transmission mechanism 14, and a drying mechanism. The drying mechanism includes a hot flue gas chamber 2 located at the bottom of the shell 1 and two drying conveyor belts 3. The at least two drying conveyor belts 3 are arranged vertically and spaced apart within the shell 1. A material channel 4 is provided between adjacent drying conveyor belts 3. The discharge end of the upper drying conveyor belt 3 corresponds to the feeding area of ​​the lower drying conveyor belt 3 through the material channel 4. The shell 1 is provided with various types of drying conveyor belts 3. The grate plate 5 has through holes 7 for hot flue gas to pass through. The drying conveyor belt 3 includes a transmission chain plate 6 and a scraper 8 extending towards the grate plate 5. The transmission mechanism 14 drives the transmission chain plate 6 to move so as to move the material along the surface of the grate plate 5. The top of the housing 1 is provided with an air outlet 10. The top of the housing 1 is provided with an inlet 11 at one end of the uppermost drying conveyor belt 3. The side of the housing 1 is provided with an outlet 12 at the end of the lowermost drying mechanism away from the inlet. The hot flue gas chamber is provided with an air inlet 9.

[0030] The through hole 7 has an inverted conical structure. For any two adjacent through holes 7 of the grate plate 5 of the drying conveyor belt 3, the opening diameter of the upper through hole 7 is smaller than the opening diameter of the lower through hole 7.

[0031] The through holes of the grate are elongated and arranged at an angle. The through holes in adjacent rows are staggered, and each through hole forms a preset angle with the length direction of the grate. The angle ranges from 10° to 45°.

[0032] Each of the material channels 4 is equipped with a flap valve 15.

[0033] The scraper 8 has a serrated structure.

[0034] The drying conveyor belt 3 has inclined side baffles 13 on both sides of the inner grate plate 5, and the width between the side baffles is smaller than the width of the scraper.

[0035] The grate adopts a stepped structure and inverted conical grate holes, with partial overlap between the grate plates to reduce material leakage.

[0036] The transmission mechanism 14 is a speed-regulating motor.

[0037] The dryer operates as follows: Material is fed into the upper drying conveyor belt from the feed inlet 11. At this point, the material is heavy due to its high initial moisture content. Driven by the variable-speed motor sprocket of the transmission mechanism 14, the transmission chain drives the scraper to move at a constant speed along the surface of the upper grate. The scraper and the upper grate work together to spread the material evenly and push it forward, preventing the material from piling up too thickly. Hot flue gas enters the hot flue gas chamber 2 from the air inlet 9, first flowing upward through the through holes of the lower grate to the middle airflow space, and then passing through the through holes of the upper grate, penetrating the damp material layer with sufficient strength. Because the total opening area of ​​the upper through holes is smaller, the hot flue gas can efficiently overcome the material resistance, fully contact the material, and quickly evaporate the surface moisture, achieving preliminary drying.

[0038] When the material is pushed to the end of the upper drying conveyor belt by the scraper, it falls through the material channel 4. The flap valve 15 in the channel is opened by the gravity of the material. After the material passes through, the flap valve 15 closes, preventing the hot flue gas from flowing back to the upper layer through the channel. The falling material enters the beginning of the lower drying conveyor belt. At this point, the material has been initially dried and its texture has become lighter. The lower scraper continues to push it along the surface of the lower grate. The hot flue gas penetrates the material at a gentler flow rate in this layer, while the side baffle 13 restricts the lateral displacement of the material, ensuring that all the material is fully moved by the scraper.

[0039] Throughout the process, the operator can adjust the speed of the variable speed motor of the transmission mechanism 14 to regulate the residence time of the material in the drying chamber, ensuring that the output moisture content meets the requirements.

[0040] Example 2:

[0041] like Figure 6-8 As shown, the difference from Embodiment 1 is that the through hole 7 is provided with a wind cap 16, which is elongated and tapered at both ends. This allows hot gas to pass through while ensuring no material leakage from the grate. The wind cap structure facilitates the passage of the scraper's teeth, and the wind cap provides a certain degree of tumbling effect on the material as it moves on the grate.

[0042] This invention provides a concept and method for a moving bed fluidized bed dryer. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A moving bed fluidized bed dryer, characterized in that, It includes a housing (1), a transmission mechanism (14), and a drying mechanism; The drying mechanism includes a hot flue gas chamber (2) located at the bottom of the housing (1) and at least two drying conveyor belts (3). The at least two drying conveyor belts (3) are arranged at intervals along the vertical direction of the housing (1) inside the housing (1). A material channel (4) is provided between two adjacent drying conveyor belts (3). The discharge end of the upper drying conveyor belt (3) corresponds to the feeding area of ​​the lower drying conveyor belt (3) through the material channel (4). A grate plate (5) is provided along the drying conveyor belt (3) inside the housing (1). The grate plate (5) is provided with a through hole (7) for the passage of hot flue gas. The drying conveyor belt (3) includes a transmission chain plate (6) and a scraper (8) extending towards the grate plate (5). The transmission mechanism (14) drives the transmission chain plate (6) to move so as to move the material along the surface of the grate plate (5); The top of the housing (1) is provided with an air outlet (10), the top of the housing (1) is provided with a feed inlet (11) at one end corresponding to the uppermost drying conveyor belt (3), the side of the housing (1) is provided with a discharge outlet (12) at the end of the lowermost drying mechanism away from the feed inlet, and the hot flue gas chamber is provided with an air inlet (9).

2. The moving bed fluidized bed dryer according to claim 1, characterized in that, The through hole (7) has an inverted conical structure.

3. The moving bed fluidized bed dryer according to claim 1, characterized in that, The through holes (7) of the grate plate (5) are elongated and arranged at an angle. The through holes (7) of adjacent rows are staggered, and each through hole (7) forms a preset angle with the length direction of the grate plate (5). The value of the angle is [10°, 45°].

4. The moving bed fluidized bed dryer according to claim 1, characterized in that, The through hole (7) of the grate plate (5) adopts a wind cap (16) structure, which is long and narrow with tapered ends.

5. The moving bed fluidized bed dryer according to claim 1, characterized in that, Each of the material channels (4) is equipped with a flap valve (15).

6. The moving bed fluidized bed dryer according to claim 1, characterized in that, The scraper (8) has a flat plate structure.

7. The moving bed fluidized bed dryer according to claim 1, characterized in that, The scraper (8) has a serrated structure.

8. The moving bed fluidized bed dryer according to claim 1, characterized in that, Side baffles (13) are provided on both sides of the grate (5).

9. The moving bed fluidized bed dryer according to claim 1, characterized in that, The drying conveyor belt (3) is inclined, and the grate (5) is arranged in a stepped manner in conjunction with the drying conveyor belt (3).

10. The moving bed fluidized bed dryer according to claim 1, characterized in that, The transmission mechanism (14) is a speed-regulating motor.

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