A screening device for a circular grain dryer

Abstract

This utility model relates to the field of grain processing machinery technology and discloses a screening device for a circulating grain dryer. It includes an elevator, a hot air section on one side of the elevator, multiple drying chambers mounted on top of the hot air section, a top platform mounted on top of each drying chamber, maintenance ladders on the outer sides of the drying chambers, and exhaust pipes installed on the side of each drying chamber near the elevator. A screening assembly is installed inside the top platform, and a grain collection hopper is installed directly below the hot air section, containing a primary filter assembly. In this utility model, the filter plates and permanent magnet iron removal plates at the bottom achieve pretreatment of large-sized and ferromagnetic impurities, effectively ensuring the safe operation of the equipment. Simultaneously, the screening assembly at the top, combining vibration and air separation, provides secondary purification of dust and debris generated after grain lifting, ensuring the cleanliness of the grain entering the silo.

Description

Technical Field

[0001] This utility model relates to the field of grain processing machinery technology, and in particular to a screening device for a circulating grain dryer. Background Technology

[0002] Currently, post-harvest drying of grains is a crucial step in ensuring their long-term safe storage, preventing mold, and guaranteeing product quality. Circulating grain dryers, as core equipment in modern agricultural production, achieve efficient and uniform dehydration by continuously circulating grains within the machine and ensuring full contact with hot air. However, the grain raw materials entering the dryer often contain various impurities. The presence of these impurities directly affects the operational stability of the drying equipment and the final drying effect. Therefore, integrating a highly efficient screening device into the drying process is particularly important.

[0003] To address the aforementioned grain screening requirements, existing circulating grain dryers typically employ a relatively simple cleaning method. One common approach is to install a separate grain cleaner outside the dryer, where the grain is first cleaned before being conveyed into the dryer's feed hopper. Another approach is to install a single-layer vibrating screen at the feed hopper inlet of the dryer body. When the grain is poured in, the vibration of the screen removes impurities significantly larger than the grains, such as straw and stones, from the screen surface, while the grain passes through the screen holes and enters the machine for circulation. The entire cleaning process is usually completed in one go, with the primary goal of preventing large foreign objects from entering the equipment.

[0004] However, existing screening solutions have significant design flaws and functional shortcomings. First, conventional screens are completely ineffective at separating metal impurities such as nails and wires mixed in with the grain. Once these metal objects enter the elevator, they are highly likely to collide and scrape against the hopper or machine wall during high-speed movement, which not only damages equipment parts but, more seriously, generates sparks. This poses a significant fire and explosion hazard in the confined space filled with grain dust.

[0005] Secondly, during the high-speed upward conveying of grains within the elevator, continuous collisions and friction occur between grains and between grains and the equipment. This process inevitably generates a large amount of new fine debris and dust, constituting secondary pollution. Traditional methods are ineffective in addressing this, causing these newly generated dust and impurities to directly mix into the grains and enter the drying chamber. They fill the gaps between grains, severely hindering the effective penetration of hot air, resulting in uneven hot air distribution. This leads to a series of problems, including low drying efficiency, increased energy consumption, and poor grain drying uniformity, while also reducing the cleanliness and value of the finished grain.

[0006] To address the above problems, a screening device for a circulating grain dryer is proposed. Utility Model Content

[0007] To overcome the above shortcomings, this utility model provides a screening device for a circulating grain dryer, aiming to solve the safety hazard caused by the inability of an existing screening device for a circulating grain dryer to effectively separate ferromagnetic impurities.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a screening device for a circulating grain dryer, comprising an elevator, a hot air section on one side of the elevator, multiple drying chambers mounted on the top of the hot air section, a top platform mounted on the top of each drying chamber, maintenance ladders on the outer sides of the multiple drying chambers, exhaust pipes mounted on the side of each drying chamber near the elevator, a screening assembly inside the top platform, a grain collection hopper mounted directly below the hot air section, a primary filter assembly inside the grain collection hopper, the primary filter assembly including a filter screen, the filter screen being fixedly connected to the inner bottom of the grain collection hopper, a side transport plate being inclinedly mounted on the inner bottom of the grain collection hopper, a transport chamber being provided between the grain collection hopper and the feed inlet of the elevator, and a permanent magnet iron removal plate being mounted on one side of the inner side of the transport chamber.

[0009] As a further description of the above technical solution: A hot air furnace is installed on the outside of the hot air section, and the hot air furnace is used to heat the drying chamber.

[0010] As a further description of the above technical solution: The screening assembly includes a screening box, an air inlet panel on one side of the screening box, a dust extraction fan on the other side of the screening box, a material leakage chassis at the bottom of the screening box, multiple telescopic rods symmetrically arranged on the top of the material leakage chassis, a screen plate between the tops of the multiple telescopic rods, and a vibration motor at the bottom center of the screen plate.

[0011] As a further description of the above technical solution: The screening box is located at the top of the drying chamber, the top discharge port of the elevator is located at the top of the screening box, and the discharge port of the elevator is equipped with a conveying pipe, the bottom of which is connected to the interior of the screening box.

[0012] As a further description of the above technical solution: An electrical control cabinet is installed on one side of the hot air unit.

[0013] This utility model has the following beneficial effects: 1. In this utility model, by setting a filter plate inside the grain collection hopper, large-sized impurities such as straw and stones are effectively intercepted and separated, avoiding the risk of these hard impurities causing impact, wear, or even jamming damage to the subsequent moving parts such as the elevator bucket and chain; a permanent magnet iron removal plate is cleverly added inside the conveying bin entering the elevator, which can accurately adsorb ferromagnetic substances such as iron nails and iron filings mixed in the grain, eliminating the major safety hazard of sparks generated by metal collisions igniting grain dust, and providing basic safety guarantee for the entire drying operation process.

[0014] 2. In this invention, a screening component is installed at the top of the equipment before the grain enters the drying chamber, achieving secondary fine purification of the grain, significantly improving drying efficiency and the quality of the finished grain. It effectively separates newly generated fragments and some impurities caused by collision and friction during the lifting process. Simultaneously, the dust extraction fan creates a negative pressure airflow within the screening box through the air intake panel, precisely removing lightweight impurities such as dust, chaff, and shriveled grains from the grain material. This ensures that the grain entering the drying chamber has extremely high purity. Attached Figure Description

[0015] Figure 1 This is a three-dimensional schematic diagram of a screening device for a circulating grain dryer proposed in this utility model; Figure 2 This is a schematic diagram of the grain collection hopper of a screening device for a circulating grain dryer proposed in this utility model; Figure 3 This is a schematic diagram of the structure of a filter plate for a screening device in a circulating grain dryer proposed in this utility model; Figure 4 This is a schematic diagram of the permanent magnet iron removal plate of a screening device for a circulating grain dryer proposed in this utility model. Figure 5 This is a schematic diagram of the structure of a vibrating motor for a screening device in a circulating grain dryer, as proposed in this utility model.

[0016] Legend: 1. Elevator; 2. Hot air section; 3. Electrical control cabinet; 4. Maintenance ladder; 5. Drying silo; 6. Exhaust pipe; 7. Top platform; 8. Hot air furnace; 9. Grain collection hopper; 10. Conveying silo; 11. Filter screen; 12. Side conveying plate; 13. Permanent magnet iron removal plate; 14. Screening box; 15. Conveying pipe; 16. Air inlet panel; 17. Screening disc; 18. Vibrating motor; 19. Material leakage chassis; 20. Telescopic rod; 21. Dust extraction fan. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Reference Figure 1 - Figure 5 The present invention provides an embodiment of a screening device for a circulating grain dryer, comprising a vertically arranged elevator 1, a hot air unit 2 connected to one side of the elevator 1 via a frame, and multiple drying chambers 5 for holding and drying grains installed above the hot air unit 2; to facilitate daily inspection and maintenance by operators, a maintenance ladder 4 running through the top and bottom is provided on the outside of the multiple drying chambers 5; and to centrally control the operation of the entire set of equipment, an electrical control cabinet 3 is also installed on one side of the hot air unit 2.

[0019] During operation, clean hot air is generated by an independently set hot air furnace 8, which is transported to the hot air section 2 through pipes, and then sent into the drying chamber 5 by a fan to heat and dry the grain. The moisture removed from the grain is discharged in the form of hot and humid air through the exhaust pipe 6. The grain to be processed is first added to the grain collection hopper 9 at the bottom, where a primary filter assembly is installed. The core of this assembly is a filter screen 11 fixedly connected to the bottom inner side of the grain collection hopper 9. As the grain flows through, its grid structure effectively intercepts larger impurities such as stones and straw, achieving the first stage of coarse filtration. After preliminary screening by the filter screen 11, the grain, guided by the side transport plate 12 installed at an incline on the bottom inner side of the grain collection hopper 9, flows smoothly into the transport chamber 10 under gravity. A permanent magnet iron removal plate 13 is installed on the inner side wall of the transport chamber 10. When the grain flows through this plate, its strong magnetic force firmly attracts ferromagnetic impurities such as iron nails and wires, thus completing the second stage of safety protection for the grain. After these two stages of pretreatment, the purer and safer grain enters the feed inlet of the elevator 1 from the transport chamber 10, ready to be transported to the top of the equipment.

[0020] Grains are continuously lifted by the hopper of elevator 1 to the top platform 7 at the top of the equipment. A conveying pipe 15 is connected to the top discharge port of elevator 1, and the outlet end of the conveying pipe 15 extends into the interior of the top screening assembly, which is set directly above the drying chamber 5. The screening assembly mainly consists of a screening box 14. When grains enter the screening box 14 through the conveying pipe 15, they first fall onto the screen plate 17. A vibrating motor 18 is installed at the bottom center of the screen plate 17, and the motor is connected to the discharge base plate 19 through multiple telescopic rods 20 for support and buffer. When the vibrating motor 18 is started, it drives the entire screen plate 17 to vibrate at high frequency, causing the grains on the screen plate 17 to be thrown up, layered, and moved forward. Full grains of the correct size pass through the mesh of the screen plate 17, while larger debris or impurities are left on the screen surface and guided to the impurity outlet. During the vibratory screening, air separation and dust removal are also carried out simultaneously. The suction fan 21, installed on one side inside the screening box 14, starts working, drawing in outside air through the air intake panel 16 on the other side of the screening box 14, thus creating a stable, horizontally flowing airflow inside the screening box 14. This airflow precisely passes through the curtain of grain falling from the screen plate 17. Since impurities such as dust, chaff, and shriveled grains are much less dense than plump grains, they are easily carried away by the airflow and collected by the suction fan 21. The clean grains, after being purified by vibration and air separation, fall through the screen plate 17 into the lower discharge tray 19, and are finally evenly distributed into the drying chamber 5 below under gravity, beginning the formal circulating drying process.

[0021] Working principle: When the equipment starts working, the grains first flow through the filter plate 11 fixed to the bottom of the inner side of the grain collection hopper 9 under the action of gravity, and then are guided along the inclined side conveyor plate 12 into the conveying bin 10 between the grain collection hopper 9 and the feed inlet of the elevator 1. In the conveying bin 10, the grain flow passes through the permanent magnet iron removal plate 13 installed on one side of its interior. The pre-treated grains then enter the elevator 1. The elevator 1 vertically conveys the grains to the top platform 7 located at the top of the equipment, and sends the grains into the screening box 14 through the conveying pipe 15 at its discharge port. The grains entering the screening box 14 first fall on the screen plate 17 supported by multiple telescopic rods 20. The vibration motor 18 at the bottom of the screen plate 17 starts, driving the screen plate 17 to vibrate, causing the grains to move on the screen surface.

[0022] Meanwhile, the dust extraction fan 21 installed on one side of the screening box 14 starts working, drawing air in from the air intake panel 16 on the other side, forming a horizontal airflow that passes through the grain curtain vibrating and falling from the screen plate 17. After screening and air separation, the grain passes through the screen plate 17 and falls into the material discharge tray 19 below it. Finally, under the action of gravity, it enters the multiple drying chambers 5 below the material discharge tray 19. The hot air required for the entire drying process is supplied to the hot air section 2 by the hot air furnace 8 and then sent into the drying chambers 5. The generated moisture is discharged through the exhaust pipe 6. All processes are controlled by the electrical control cabinet 3 and maintained through the maintenance ladder 4.

Claims

1. A screening device for a circulating grain dryer, comprising an elevator (1), characterized in that: A hot air section (2) is provided on one side of the elevator (1). Multiple drying chambers (5) are installed on the top of the hot air section (2). A top platform (7) is installed on the top of the drying chambers (5). A maintenance ladder (4) is provided on the outside of the multiple drying chambers (5). A dehumidification pipe (6) is installed on the side of the multiple drying chambers (5) near the elevator (1). A screening component is provided inside the top platform (7). A grain collection hopper (9) is installed directly below the hot air section (2). A primary filter component is provided inside the grain collection hopper (9). The primary filter component includes a filter plate (11). The filter plate (11) is fixedly connected to the bottom inner side of the grain collection hopper (9). A side transport plate (12) is installed at an incline on the bottom inner side of the grain collection hopper (9). A transport chamber (10) is provided between the grain collection hopper (9) and the feed inlet of the elevator (1). A permanent magnet iron removal plate (13) is installed on one side inside the transport chamber (10).

2. A screening device for a circulating grain dryer according to claim 1, characterized in that: A hot air furnace (8) is installed on the outside of the hot air section (2), and the hot air furnace (8) is used to heat the drying chamber (5).

3. A screening device for a circulating grain dryer according to claim 1, characterized in that: The screening assembly includes a screening box (14), an air inlet panel (16) is provided on one side of the screening box (14), a dust suction fan (21) is installed on the other side of the screening box (14), a material leakage chassis (19) is installed at the bottom of the screening box (14), a plurality of telescopic rods (20) are symmetrically arranged on the top of the material leakage chassis (19), a screen plate (17) is installed between the tops of the plurality of telescopic rods (20), and a vibration motor (18) is installed at the bottom center of the screen plate (17).

4. A screening device for a circulating grain dryer according to claim 3, characterized in that: The screening box (14) is located on top of the drying chamber (5), the top outlet of the elevator (1) is located on top of the screening box (14), and the outlet of the elevator (1) is equipped with a conveying pipe (15), the bottom of which is connected to the interior of the screening box (14).

5. A screening device for a circulating grain dryer according to claim 1, characterized in that: An electrical control cabinet (3) is provided on one side of the hot air unit (2).

Images