A hot air supply device for a low-temperature circulating grain dryer

Abstract

The present invention relates to the technical field of grain drying equipment, and particularly relates to a hot air supply device for a low-temperature circulating grain dryer, which includes an air intake channel, an air supply device, and an angled box; the air intake channel includes a tempering channel, a drying channel, and a cooling channel; the tempering channel is connected to the upper layer of the tower body; the drying channel is connected to the middle layer of the tower body; the cooling channel is connected to the lower layer of the tower body; the air supply device is connected to the air intake channel; the angled box is connected to the tower body; by dividing the hot air intake channel into three layers, the hot air flow rate in the middle layer is the fastest, and as the humidity on the exhaust side increases, the flow area of the drying channel will automatically decrease, making the intake speed of the drying hot air faster, capable of quickly taking away the moisture, and the number of angled boxes for exhaust is more than that for intake, increasing the exhaust volume per unit time; solving the problem that the humidity on the side where the hot air enters the drying chamber is low and the humidity on the exhaust side is high, resulting in poor drying effect of the grains near the exhaust channel side.

Description

Technical Field

[0001] The present invention relates to the technical field of grain drying equipment, and particularly relates to a hot air supply device for a low-temperature circulating grain dryer. Background Art

[0002] A low-temperature circulating grain dryer is a device specifically used for drying grains. It mainly heats air to 40 to 70 degrees Celsius, and then sends the hot air into the drying chamber through a supply device to evaporate the moisture in the grains. The supply device of the grain dryer needs to divide the hot air into multiple layers and evenly discharge it to the surface of the grains to avoid uneven heating of the grains, resulting in scorching or insufficient drying.

[0003] The hot air supply device of a grain dryer usually uses a fan to send the air heated in the heating system into the supply duct. The supply channel then sends the air into the angled box in the drying chamber and flows out from the angled box to the surface of the grains, so that the hot air is evenly distributed on the surface of the grains. However, since the hot air continuously flows into the angled box from the side wall position of the drying chamber, heat accumulation will occur at the side wall position of the drying chamber, resulting in the grains near the side wall being overheated and scorched. The prior art has proposed good solutions to this problem. For example, a downflow tower grain dryer with the patent publication number CN104776704B avoids the hot air from contacting the side wall of the drying chamber by setting the isolation of the upper baffle and the lower baffle, thereby preventing the side wall of the drying chamber from being overheated by the high-temperature hot air and causing the grains to be overheated and scorched, and ensuring the drying effect of the grains.

[0004] Although the prior art has solved the problem of heat accumulation at the side wall position caused by the hot air entering from the side wall of the drying chamber, resulting in the grains at the side wall being overheated and scorched, there are still the following problems: Since the drying hot air will diffuse from the bottom of the angled box to the surface of the grains after entering the angled box with the opening facing the intake channel, and will enter the angled box with the opening facing the exhaust channel after taking away the moisture in the grains, a large amount of moisture will accumulate at the exhaust channel position. At this time, the humidity on the intake side where the hot air enters the drying chamber will be low, and the humidity on the exhaust side will be high, resulting in insufficient drying of the grains near the exhaust channel side and an unsatisfactory drying effect of the grains. Especially in winter, when the outside temperature is low, the moisture in the hot and humid air on the exhaust channel side will be more likely to condense, further reducing the drying effect of the grains on the exhaust channel side.

[0005] In view of the above situation, in order to overcome the above technical problems, the present invention designs a hot air supply device for a low-temperature circulating grain dryer. Summary of the Invention

[0006] The present invention provides a hot air supply device for a low-temperature circulating grain dryer, which solves the problem that the humidity on the side where hot air enters the drying chamber is low and the humidity on the side where it is discharged is high, resulting in poor drying effect of the grains near the exhaust passage. By dividing the hot air inlet passage into three layers, the hot air flow rate in the middle layer is the fastest, and as the humidity on the exhaust side increases, the flow area of the drying passage will automatically decrease, making the intake speed of the drying hot air faster, and capable of quickly taking away the moisture. At the same time, the horn-shaped box is designed to have a gradually decreasing flow area in the direction from the inlet to the exhaust, and the number of horn-shaped boxes for exhaust is more than that for intake, which improves the exhaust volume per unit time, ensures that the humidity in the drying chamber is controlled within the allowable range, and guarantees the drying effect.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A hot air supply device for a low-temperature circulating grain dryer, comprising a tower body, an exhaust device and a feeding device, and further comprising an intake passage, a air supply device and a horn-shaped box; the intake passage includes a tempering passage, a drying passage and a cooling passage; the tempering passage is connected to the upper layer of the tower body; the drying passage is connected to the middle layer of the tower body, and when the humidity at one end of the tower body near the exhaust device rises, the drying passage contracts to reduce the flow area and accelerate the hot air flow rate; the cooling passage is connected to the lower layer of the tower body; the air supply device is connected to the intake passage, and when the air supply device works, hot air is sent into the tempering passage, the drying passage and the cooling passage; the horn-shaped box includes an air inlet box and an air outlet box; the air inlet box is connected to the tower body and communicates with the intake passage; the air outlet box is connected to the tower body and communicates with the exhaust device, and after the hot and humid air enters the air outlet box radially, it flows axially and flows towards the exhaust device.

[0009] Preferably, a partition upper plate is arranged between the tempering passage and the drying passage; a partition lower plate is arranged between the drying passage and the cooling passage; the included angle formed by the extension lines of the partition upper plate and the partition lower plate faces the intake passage side.

[0010] In the above solution, this layout can make the flow area of the hot air in the drying passage gradually decrease, while the flow rate of the hot air is constant. At this time, the flow rate of the hot air will increase. Since the grain drying process is divided into three steps: tempering, drying and cooling, the most moisture is evaporated during the drying process. Therefore, during the drying process, it is necessary to ensure a relatively high flow rate of the hot air to take away all the moisture, so as to avoid the influence of humidity on the drying effect; and because of the partition upper plate and the partition lower plate, the flow areas of the tempering passage and the cooling passage will increase, thereby slowing down the flow rate of the hot air, making the temperature rise slower during the tempering and cooling stages, and ensuring that moisture can be slowly evaporated during these two stages to avoid the phenomenon of grain cracking and coking.

[0011] Preferably, the air supply device includes an air supply fan, two fixed rotating shafts, two connecting rotating seats, and an expansion assembly; the air supply fan is installed facing the drying channel; the two fixed rotating shafts are respectively connected to the upper partition plate and the lower partition plate; the two connecting rotating seats are respectively connected to the upper partition plate and the lower partition plate; the expansion assembly is connected to the connecting rotating seat.

[0012] In the above solution, the air supply fan sends air into the air inlet channel, and the air supply fan is facing the drying channel, which can make the hot air flow rate and flow volume in the drying channel higher. The amount of hot air entering the tempering channel and the cooling channel is less and the speed is slower compared with the drying channel, so as to better help the grains go through a process of gradually increasing and then decreasing temperature, and then ensure better grain drying effect; and under the action of the connecting rotating seat, the ventilation speed of the drying channel can be automatically changed, so as to better remove moisture.

[0013] Preferably, the expansion assembly includes a sliding cavity, an expansion rubber, a connecting push rod, and an adjusting spring; the sliding cavity is opened in the tower body; the expansion rubber is arranged in the sliding cavity and is located on the side of the sliding cavity close to the exhaust device; the connecting push rod is connected between the expansion rubber and the connecting rotating seat; the adjusting spring is connected between the connecting push rod and the sliding cavity.

[0014] In the above solution, when the humidity is high, the expansion rubber will absorb the moisture in the hot air and expand. And since the position of the expansion rubber is not in the air outlet box but in the grains, on the one hand, it can absorb the moisture near the exhaust channel, and on the other hand, when the humidity is too high and the amount of absorbed moisture is large, it will push the connecting rotating seat, making the angle formed by the upper partition plate and the lower partition plate smaller. At this time, the air inlet speed of the hot air will further increase, increasing the circulation speed of the hot air, so as to take away the moisture. In the case of low humidity, the air inlet speed of the hot air is kept moderate, which can save the loss of hot air and avoid the too fast circulation speed of the hot air, resulting in the premature discharge of the hot air from the tower body and too low heat utilization rate.

[0015] Preferably, the air inlet boxes are linearly arranged in the tower body along the horizontal direction, and the openings of the air inlet boxes face the air inlet channel. Multiple rows of air inlet boxes are arranged along the vertical direction, and the distance between each row of air inlet boxes first decreases and then increases from the upper layer to the lower layer of the tower body; the air outlet boxes are arranged in multiple rows in the same way as the air inlet boxes, each row of air outlet boxes is arranged at intervals with each row of air inlet boxes, and the number of rows and columns of the air outlet boxes is more than that of the air inlet boxes, and the openings of the air outlet boxes face the exhaust device side.

[0016] In the above solution, by controlling the density of the incoming hot air to first decrease and then increase in the direction from the upper layer to the lower layer of the tower body, it is ensured that the temperature inside the tower body changes from low to high and then to low from top to bottom. On the one hand, the grains are gradually heated, balancing the temperature difference inside and outside the grains, enabling their moisture to evenly diffuse from the inside to the outside. Then, the high temperature directly acts on the grains, causing their surfaces to become charred. Moreover, the process of gradually increasing and decreasing the temperature helps the drying process of the grains to be more uniform, and the moisture in each part of the grains can evaporate under relatively balanced conditions, reducing quality problems caused by uneven drying. On the other hand, since the number of air inlet boxes and air outlet boxes in the middle layer is relatively large, the flow area of the hot air can be increased. In the middle layer, the hot air can flow quickly and carry away the moisture, preventing the humidity from being too high on one side of the tower body's exhaust device. And since the number of rows and columns of the air outlet boxes is more than that of the air inlet boxes, the outlet area of the humid hot air can be increased, thus helping the humid hot air to be quickly discharged and further reducing the humidity on one side of the exhaust device.

[0017] Preferably, a plurality of air-diffusing holes are formed on the surface of the air inlet box, and the cross-sectional area of the air inlet box gradually decreases along the intake passage towards the exhaust device; the cross-sectional area of the air outlet box gradually decreases along the intake passage towards the exhaust device, and a flow guiding component is arranged inside the air outlet box.

[0018] In the above solution, the air-diffusing holes on the surface of the air inlet box can quickly diffuse the hot air to the surface of the grains. On the one hand, it ensures the uniformity of drying, and on the other hand, it makes the flow rate of the hot air faster, enabling the hot air carrying moisture to quickly flow out, preventing the humidity from being too high and incomplete drying. By changing the cross-sectional area of the air outlet box, the hot air carrying moisture can be made to flow out faster, and the closer it is to the exhaust device, the faster its flow rate, achieving the rapid discharge of moisture and avoiding the problem of incomplete drying caused by too high humidity on one side of the exhaust device. Through the flow guiding component, the air entering the air outlet box can quickly flow out along a predetermined path, thus preventing the accumulation of moisture.

[0019] Preferably, the air-diffusing holes are conical holes, with the larger-diameter end facing the inside of the air inlet box, and the number of air-diffusing holes decreases along the direction of the decreasing cross-sectional area of the air inlet box.

[0020] In the above solution, the conical holes can make the hot air form a diffused state when discharged, thus making the distribution of the hot air more uniform. Since the cross-sectional area of the air inlet box gradually decreases, the wind speed can gradually increase. Since the number of air-diffusing holes decreases along the direction of the decreasing cross-sectional area of the air inlet box, the amount of hot air flowing out on both sides of the air inlet and outlet of the drying chamber can be controlled to tend to be balanced, thus preventing the flow rate from being fast on one side and slow on the other side, which may lead to uneven distribution of the hot air volume on both sides and different drying effects on both sides.

[0021] Preferably, the flow guiding assembly includes a flow guiding rotating shaft and a plurality of flow guiding impellers; the flow guiding rotating shaft is installed inside the air outlet box; the plurality of flow guiding impellers are linearly arranged on the flow guiding rotating shaft, and an adsorption layer is arranged on the surface of each flow guiding impeller.

[0022] In the above solution, after the humid and hot air enters the air outlet box from the radial direction, it will drive the flow guiding impellers to rotate. When the flow guiding impellers rotate, the movement direction of the humid and hot air will change from radial to axial. And in cooperation with the exhaust device, the humid and hot air can be quickly discharged from the air inlet box, avoiding excessive humidity. And when the humid and hot air passes through the surface of the flow guiding impeller, the moisture in it will be absorbed by the adsorption layer, so as to achieve the purpose of reducing humidity.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. Compared with the existing grain dryer, the present invention is provided with a tempering channel, a drying channel and a cooling channel. The three channels are separated by a movable upper partition plate and a lower partition plate. Since an opening is formed between the upper partition plate and the lower partition plate facing the air supply fan, at this time, the hot air flow area of the drying channel gradually decreases along the air inlet direction, and the flow areas of the tempering channel and the cooling channel gradually increase along the air inlet direction, which can increase the flow rate of the hot air in the middle drying layer, so as to help the evaporated moisture to be quickly taken away. The flow rates of the upper and lower layers are relatively slow, so that the grains can be slowly evaporated, avoiding the phenomenon of cracking and coking of the grains due to sudden exposure to high temperature. As the humidity increases, the upper partition plate and the lower partition plate will reduce the included angle between them under the action of the connecting turntable. At this time, the air inlet speed of the hot air will be further increased, so as to achieve a moderate air inlet speed when the humidity is low, avoiding excessive heat energy loss, and a faster air inlet speed when the humidity is high, so that the hot air flow rate is higher and the moisture can be taken away faster, avoiding the drying effect of the grains being unsatisfactory due to excessive humidity.

[0025] 2. The present invention sets both the air outlet box and the air inlet box to have a structure in which the flow area gradually decreases from the air inlet side to the air outlet side, so that the hot air flow rate on the side of the tower body close to the exhaust device is faster, thus ensuring the humidity balance between the air inlet side and the air outlet side, and further ensuring the drying effect. And in cooperation with the layout design that the number of air outlet boxes is more than that of air inlet boxes, the total area of the air outlet openings of all air outlet boxes can be made equal to the total area of the air inlet openings of all air inlet boxes, so as to maintain the balance of the air inlet volume and the air outlet volume, ensure that the humid and hot air on the air outlet side can be smoothly and quickly discharged, and further ensure that the grains on the side close to the exhaust device have a good drying effect.

[0026] 3. In the present invention, a guiding impeller is provided in the air outlet box, so that when the humid and hot air enters the air outlet box in the radial direction, it can drive the guiding impeller to rotate. When the guiding impeller rotates, the flow direction of the humid and hot air will change from radial to axial. At this time, the humid and hot air will flow out quickly, avoiding the accumulation of moisture in the tower body and resulting in an unsatisfactory drying effect. Moreover, an adsorption layer is provided on the surface of the guiding impeller, which can absorb some moisture when the humid and hot air passes through the surface of the guiding impeller. When the humidity is too high, the adsorption layer can quickly control the humidity within an appropriate range through the adsorption effect. Combining with the reduction of the flow area of the drying channel and the increase of the intake speed of hot air when the humidity increases, the guiding impeller can rotate faster under the action of the rapid flow of gas, enabling the adsorption layer to come into full contact with the humid and hot air, improving the adsorption effect, and thus ensuring the grain drying effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 is the overall structure diagram of the present invention;

[0029] Figure 2 is the internal structure diagram of the present invention;

[0030] Figure 3 is the side sectional view of the present invention;

[0031] Figure 4 is the layout diagram of the air inlet box and the air outlet box of the present invention;

[0032] Figure 5 is the sectional view of the expansion component of the present invention;

[0033] Figure 6 is the structure diagram of the air inlet box of the present invention;

[0034] Figure 7 is the structure diagram of the air outlet box of the present invention;

[0035] Figure 8 is the schematic diagram of the turning direction of the upper partition plate and the lower partition plate;

[0036] In the figure: 1. Tower body; 2. Exhaust device; 3. Feeding device; 4. Air inlet channel; 41. Conditioning channel; 42. Drying channel; 43. Cooling channel; 44. Upper partition plate; 45. Lower partition plate; 5. Air supply device; 51. Air supply fan; 52. Fixed rotating shaft; 53. Connecting rotating seat; 54. Expansion assembly; 541. Sliding cavity; 542. Expanding rubber; 543. Connecting push rod; 544. Adjusting spring; 6. Angular box; 61. Air inlet box; 611. Air dispersing holes; 62. Air outlet box; 621. Flow guiding assembly; 6211. Flow guiding rotating shaft; 6212. Flow guiding impeller; 6213. Adsorption layer. Detailed implementation mode

[0037] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings of the specification and specific implementation modes.

[0038] Please refer to Figures 1 to 8 , the present invention provides a hot air supply device for a low-temperature circulating grain dryer, and the technical solution is as follows:

[0039] As a specific implementation mode of the present invention, refer to Figure 1 , Figure 2 and Figure 3 ; A hot air supply device for a low-temperature circulating grain dryer, including a tower body 1, an exhaust device 2 and a feeding device 3, further including an air inlet channel 4, an air supply device 5 and an angular box 6; the air inlet channel 4 includes a conditioning channel 41, a drying channel 42 and a cooling channel 43; the conditioning channel 41 is connected to the upper layer of the tower body 1; the drying channel 42 is connected to the middle layer of the tower body 1, and when the humidity at one end of the tower body 1 near the exhaust device 2 rises, the drying channel 42 contracts to reduce the flow area and accelerate the flow rate of hot air; the cooling channel 43 is connected to the lower layer of the tower body 1; the air supply device 5 is connected to the air inlet channel 4, and when the air supply device 5 works, hot air is sent into the conditioning channel 41, the drying channel 42 and the cooling channel 43; the angular box 6 includes an air inlet box 61 and an air outlet box 62; the air inlet box 61 is connected to the tower body 1 and communicates with the air inlet channel 4; the air outlet box 62 is connected to the tower body 1 and communicates with the exhaust device 2, and after the humid hot air enters the air outlet box 62 radially, it flows axially and flows towards the exhaust device 2, accelerating the outflow speed of the humid hot air and ensuring that the humidity in the tower body 1 is maintained within an appropriate range.

[0040] As a specific implementation mode of the present invention, refer to Figure 3 and Figure 4A partition upper plate 44 is provided between the tempering channel 41 and the drying channel 42; a partition lower plate 45 is provided between the drying channel 42 and the cooling channel 43; the included angle formed by the extension lines of the partition upper plate 44 and the partition lower plate 45 faces the intake channel 4. This arrangement can make the flow area of the hot air in the drying channel 42 gradually decrease, while the flow rate of the hot air is constant. At this time, the flow velocity of the hot air will increase. Since the drying process of the grains is divided into three steps: tempering, drying, and cooling, the most moisture is evaporated during the drying process. Therefore, during the drying process, it is necessary to ensure a relatively high flow velocity of the hot air to take away all the moisture, thereby avoiding the influence of humidity on the drying effect; and due to the tempering channel 41 and the cooling channel 43, under the action of the partition upper plate 44 and the partition lower plate 45, the flow area will increase, thereby slowing down the flow velocity of the hot air, making the temperature rise slower during the tempering and cooling stages, ensuring that moisture can be slowly evaporated during these two stages, and avoiding the phenomenon of cracking and coking of the grains.

[0041] As a specific embodiment of the present invention, refer to Figure 3 and Figure 8 The air supply device 5 includes an air supply fan 51, two fixed rotating shafts 52, two connecting rotating seats 53, and an expansion assembly 54; the air supply fan 51 is installed facing the drying channel 42; the two fixed rotating shafts 52 are respectively connected to the partition upper plate 44 and the partition lower plate 45; the two connecting rotating seats 53 are respectively connected to the partition upper plate 44 and the partition lower plate 45; the expansion assembly 54 is connected to the connecting rotating seat 53. The air is sent into the intake channel 4 through the air supply fan 51, and the air supply fan 51 is facing the drying channel 42, which can make the flow velocity and flow rate of the hot air in the drying channel 42 higher, while the amount of hot air entering the tempering channel 41 and the cooling channel 43 is less and the speed is slower than that in the drying channel 42, thereby better helping the grains to go through a process of gradually increasing and then gradually decreasing temperature, and further ensuring a better drying effect of the grains; and under the action of the connecting rotating seat 53, the ventilation speed of the drying channel 42 can be automatically changed, so as to better take away the moisture.

[0042] As a specific embodiment of the present invention, refer to Figure 5; The expansion assembly 54 includes a sliding cavity 541, an expansion rubber 542, a connecting push rod 543, and an adjusting spring 544; the sliding cavity 541 is opened in the tower body 1; the expansion rubber 542 is arranged in the sliding cavity 541 and is located on the side of the sliding cavity 541 close to the exhaust device 2, and the material of the expansion rubber 542 is selected as water-swellable rubber. These rubber materials contain a relatively high proportion of hydrophilic groups, which can combine with water molecules and absorb moisture, causing expansion. However, due to its high viscosity and high molecular structure, the moisture will not easily flow out. Especially under extrusion, when the air outside the expansion rubber 542 becomes dry hot air, the moisture in it will be slowly carried away by the dry hot air. At this time, on the one hand, it can avoid the influence on grain drying caused by the outflow of moisture from the expansion rubber 542. On the other hand, when the dry hot air slowly takes out the moisture from the expansion rubber 542 during the rapid flow on the exhaust side, the moisture accumulated in the expansion rubber 542 can be used to evaporate and absorb excessive heat to avoid the phenomenon of rapid temperature rise of the grain on the exhaust side leading to scorching, and the expansion rubber 542 can be reused; the connecting push rod 543 is connected between the expansion rubber 542 and the connecting turntable 53; the adjusting spring 544 is connected between the connecting push rod 543 and the sliding cavity 541. When the humidity is relatively high, the expansion rubber 542 will absorb the moisture in the hot air and expand. And because the position where the expansion rubber 542 is located is not in the air outlet box 62 but in the grain, so when absorbing moisture, on the one hand, it can absorb the moisture near the exhaust passage, and on the other hand, when the humidity is too high and the absorbed moisture is relatively large, it will push the connecting turntable 53, making the angle formed by the upper partition plate 44 and the lower partition plate 45 smaller. At this time, the inlet air speed of the hot air will further increase, increasing the flow rate of the hot air, so as to take away the moisture. And in the case of relatively low humidity, keeping the inlet air speed of the hot air moderate can save the loss of hot air, avoid the too fast flow rate of the hot air, and prevent the premature discharge of the hot air from the tower body 1 resulting in too low heat utilization rate.

[0043] As a specific embodiment of the present invention, refer to Figure 4 and Figure 5; The air inlet boxes 61 are arranged in a linear array along the horizontal direction inside the tower body 1, and the openings of the air inlet boxes 61 face the air inlet channel 4. A plurality of rows of air inlet boxes 61 are arranged along the vertical direction, and the distance between each row of air inlet boxes 61 first decreases and then increases from the upper layer to the lower layer of the tower body 1; The air outlet boxes 62 are arranged in multiple rows in the same way as the air inlet boxes 61. Each row of air outlet boxes 62 is arranged at intervals with each row of air inlet boxes 61, and the number of rows and columns of the air outlet boxes 62 is more than that of the air inlet boxes 61. The openings of the air outlet boxes 62 face the exhaust device 2 side. By controlling the density of the incoming hot air to first decrease and then increase from the upper layer to the lower layer of the tower body 1, it is ensured that the temperature inside the tower body 1 changes from low to high and then to low from top to bottom. On the one hand, the grains are gradually heated, balancing the temperature difference inside and outside the grains, enabling their moisture to evenly diffuse from the inside to the outside. Then, the high temperature directly acts on the grains, causing their surfaces to coke. Moreover, the process of gradually increasing and decreasing the temperature helps the drying process of the grains to be more uniform, and the moisture in each part of the grains can evaporate under relatively balanced conditions, reducing quality problems caused by uneven drying; On the other hand, since the number of air inlet boxes 61 and air outlet boxes 62 in the middle layer is relatively large, the flow area of the hot air can be increased. In the middle layer, the hot air can flow quickly and carry away the moisture, preventing the humidity on the side of the exhaust device 2 of the tower body 1 from being too high; And since the number of rows and columns of the air outlet boxes 62 is more than that of the air inlet boxes 61, the outflow area of the humid hot air can be increased, thus helping the humid hot air to be quickly discharged and further reducing the humidity on the side of the exhaust device 2.

[0044] As a specific implementation manner of the present invention, refer to Figure 5 , Figure 6 and Figure 7 ; A plurality of air-diffusing holes 611 are formed on the surface of the air inlet box 61, and the cross-sectional area of the air inlet box 61 gradually decreases from the air inlet channel 4 to the exhaust device 2 direction; The cross-sectional area of the air outlet box 62 gradually decreases from the air inlet channel 4 to the exhaust device 2 direction, and a flow guiding component 621 is arranged inside the air outlet box 62. The air-diffusing holes 611 on the surface of the air inlet box 61 can quickly diffuse the hot air to the surface of the grains. On the one hand, it ensures the uniformity of drying, and on the other hand, it makes the flow speed of the hot air faster, enabling the hot air carrying moisture to quickly flow out, preventing the humidity from being too high and the drying from being incomplete; By changing the cross-sectional area of the air outlet box 62, the hot air carrying moisture can be made to flow out faster, and the closer it is to the exhaust device 2, the faster its flow speed, achieving the rapid discharge of moisture and preventing the problem of incomplete drying caused by too high humidity on the side of the exhaust device 2; Through the flow guiding component 621, the air entering the air outlet box 62 can flow out quickly along a predetermined path, thus preventing moisture from accumulating.

[0045] As a specific implementation manner of the present invention, refer to Figure 6; The air-diffusing holes 611 are tapered holes, the end with a larger aperture faces the inside of the air inlet box 61, and the number of air-diffusing holes 611 decreases along the direction in which the cross-sectional area of the air inlet box 61 decreases. The tapered holes can cause the hot air to form a diffused state when discharged, so that the hot air is more evenly distributed. And for the air inlet box 61, its wall surface can be thickened, and a heat-insulating layer is provided inside it, so as to avoid the high heat conduction efficiency of the air inlet box 61 causing the grains at the surface position of the air inlet box 61 to be scorched. And the increase in the thickness of the air inlet box 61 can make the depth of the air-diffusing holes 611 deeper, so that the air-diffusing holes 611 can effectively pressurize and diffuse the gas and eject it. Since the cross-sectional area of the air inlet box 61 gradually decreases, the wind speed can gradually increase; since the number of air-diffusing holes 611 decreases along the direction in which the cross-sectional area of the air inlet box 61 decreases, the amount of hot air flowing out on both sides of the air inlet and outlet of the drying chamber can be controlled to tend to be balanced, so as to avoid uneven distribution of the hot air volume on both sides due to different flow rates on one side and slow flow rate on the other side, resulting in different drying effects on both sides.

[0046] As a specific embodiment of the present invention, refer to Figure 7 ; The flow guiding assembly 621 includes a flow guiding rotating shaft 6211 and a plurality of flow guiding impellers 6212; the flow guiding rotating shaft 6211 is installed inside the air outlet box 62; the plurality of flow guiding impellers 6212 are linearly arranged on the flow guiding rotating shaft 6211, and the flow guiding impellers 6212 are axial flow impellers capable of converting radial flow into axial flow, and an adsorption layer 6213 is provided on the surface of each flow guiding impeller 6212. After the humid and hot air enters the air outlet box 62 from the radial direction, it will drive the flow guiding impellers 6212 to rotate. When the flow guiding impellers 6212 rotate, the movement direction of the humid and hot air will change from radial to axial, and cooperating with the exhaust device 2, the humid and hot air can be quickly discharged from the air inlet box 61 to avoid excessive humidity; and when the humid and hot air passes through the surface of the flow guiding impellers 6212, the moisture in it will be absorbed by the adsorption layer 6213, so as to achieve the purpose of reducing humidity; cooperating with the reduction of the flow area of the drying channel 42 when the humidity increases and the increase of the hot air intake speed, the flow guiding impellers 6212 can rotate faster under the action of the rapid gas flow, so that the adsorption layer 6213 is in full contact with the humid and hot air, improving the adsorption effect, and further ensuring the grain drying effect.

[0047] Workflow: Under the action of the air supply fan 51, hot air enters the air inlet box 61 from the tempering channel 41, the drying channel 42 and the cooling channel 43 respectively. The hot air passing through the drying channel 42 will be accelerated. After entering the air inlet box 61, it flows out to the surface of the grain through the bottom of the air inlet box 61 and the air dispersion holes 611, takes away the moisture in the grain, and then enters the air outlet box 62 in the radial direction. In the air outlet box 62, the flow direction of the humid and hot air changes to the axial direction and a part of the moisture in it will be absorbed. At the same time, when the flow area of the air outlet box 62 decreases, the humid and hot air will be accelerated to discharge, avoiding excessive humidity on the exhaust side.

[0048] Specifically, under the action of the air supply fan 51, hot air is sent into the tempering channel 41, the drying channel 42 and the cooling channel 43. In order to ensure that the temperature change of the grain during the drying process is gradually increased and then decreased to ensure the drying effect of the grain, through the included angle formed between the upper partition plate 44 and the lower partition plate 45, the flow area of the drying channel 42 gradually decreases along the air inlet direction, so as to accelerate the hot air passing through the drying channel 42. On the contrary, the flow areas of the tempering channel 41 and the cooling channel 43 gradually increase along the air inlet direction. At this time, the hot air entering the tempering channel 41 and the cooling channel 43 will decelerate, so as to ensure that the grain is gradually heated after entering the tower body 1, avoiding the direct exposure of the grain to high temperature, resulting in the rapid evaporation of the surface moisture of the grain while the internal moisture cannot evaporate, thus causing the phenomenon of scorching.

[0049] During the drying stage, the most moisture evaporates from the grains. At this time, the hot and humid air is discharged from the position of the exhaust device 2, resulting in too high humidity on the exhaust side inside the tower body 1. To prevent the excessive humidity on the exhaust side inside the tower body 1 from affecting the normal drying of the grains, when the humidity on the exhaust side increases, the expansion rubber 542 will absorb the moisture in the hot and humid air. The expansion rubber 542 absorbs moisture and expands, pushing the connecting push rod 543, which will push the connecting rotating seat 53 to reduce the included angle formed between the separating upper plate 44 and the separating lower plate 45. At this time, the flow area of the drying channel 42 will be further reduced. At this time, the intake speed of the drying hot air will be further increased, and the drying hot air will quickly carry away the hot and humid air, thus ensuring that the humidity inside the tower body 1 is controlled within an appropriate range. When the drying hot air enters the air inlet box 61, its flow rate will increase as the flow area of the air inlet box 61 gradually decreases. At this time, the hot air reaching the side of the tower body 1 near the exhaust device 2 has a faster flow rate, thus preventing the accumulation of hot and humid air and resulting in too high humidity. The hot air in the air inlet box 61 flows out from the air diffusing holes 611 and the bottom of the air inlet box 61 to the surface of the grains, and the drying hot air flowing out from the air diffusing holes 611 will be ejected in a diffused state, enabling the grains to be evenly heated. After the drying hot air evaporates the moisture of the grains, it will become hot and humid air and enter the air outlet box 62 radially. At this time, the hot and humid air will cause the guide vane impeller 6212 to rotate. Under the action of the blades of the guide vane impeller 6212, the hot and humid air will change from radial flow to axial flow, thus facilitating the rapid discharge of the hot and humid air from the tower body 1. Moreover, the faster the intake speed of the drying hot air, the higher the flow rate of the hot and humid air will be. The faster the hot and humid air enters the air outlet box 62, the higher the rotation speed of the guide vane impeller 6212 will be. The adsorption layer 6213 on the guide vane impeller 6212 will have more sufficient contact with the hot and humid air, enabling excessive moisture to be absorbed into the adsorption layer 6213, helping to quickly reduce the humidity inside the tower body 1 and further ensuring the drying effect.

[0050] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A hot air supply device for a low-temperature circulating grain dryer, comprising a tower body (1), an exhaust device (2) and a feeding device (3), characterized in that: The tower body (1) further comprises an air intake passage (4), an air supply device (5) and an angle box (6); the air intake passage (4) comprises a slow-release passage (41), a drying passage (42) and a cooling passage (43); the slow-release passage (41) is connected to the upper layer of the tower body (1); the drying passage (42) is connected to the middle layer of the tower body (1); when the humidity in the tower body (1) near one end of the exhaust device (2) increases, the drying passage (42) contracts to reduce the flow area and accelerate the flow rate of hot air; the cooling passage (43) is connected to the lower layer of the tower body (1); the air supply device (5) is connected to the The air supply device (5) is connected to the air inlet channel (4), and when in operation, hot air is supplied to the slow drying channel (41), the drying channel (42), and the cooling channel (43) at different speeds; the angular box (6) comprises an air inlet box (61) and an air outlet box (62); the air inlet box (61) is connected to the tower body (1) and communicates with the air inlet channel (4); the air outlet box (62) is connected to the tower body (1) and communicates with the exhaust device (2); the hot and humid air radially enters the air outlet box (62), then flows axially and flows toward the exhaust device (2); An upper partition plate (44) is provided between the cooling channel (41) and the drying channel (42); a lower partition plate (45) is provided between the drying channel (42) and the cooling channel (43); and an angle formed by the extension lines of the upper partition plate (44) and the lower partition plate (45) is oriented toward the air inlet channel (4).

2. A hot air supply device for a low-temperature circulating grain dryer according to claim 1, characterized in that: The air supply device (5) comprises an air supply fan (51), two fixed rotating shafts (52), four connecting rotating seats (53) and an expansion assembly (54); the air supply fan (51) is installed facing the drying channel (42); the two fixed rotating shafts (52) are respectively connected to the partition upper plate (44) and the partition lower plate (45); two of the four connecting rotating seats (53) are arranged on the left and right sides of the upper part of the partition upper plate (44), and the other two connecting rotating seats (53) are arranged on the left and right sides of the lower part of the partition lower plate (45); and the expansion assembly (54) is connected to the connecting rotating seat (53).

3. A hot air supply device for a low-temperature circulating grain dryer according to claim 2, characterized in that: The expansion assembly (54) comprises a sliding chamber (541), an expansion rubber (542), a connecting push rod (543) and an adjusting spring (544); the sliding chamber (541) is opened in the tower body (1); the expansion rubber (542) is arranged in the sliding chamber (541) and is located on a side of the sliding chamber (541) close to the exhaust device (2); the connecting push rod (543) is connected between the expansion rubber (542) and the connecting rotating seat (53); and the adjusting spring (544) is connected between the connecting push rod (543) and the sliding chamber (541).

4. The hot air supply device for a low-temperature circulating grain dryer according to claim 1, characterized in that: The air inlet boxes (61) are arranged in a linear array in the horizontal direction inside the tower body (1), and the end openings of the air inlet boxes (61) face the air inlet channel (4). A plurality of rows of air inlet boxes (61) are arranged in the vertical direction, and the distance between each row of air inlet boxes (61) first decreases and then increases in a direction from the upper layer of the tower body (1) to the lower layer of the tower body (1). The air outlet boxes (62) are arranged in a plurality of rows like the air inlet boxes (61), and each row of air outlet boxes (62) is arranged at intervals from each row of air inlet boxes (61), and the number of rows and columns of the air outlet boxes (62) is greater than that of the air inlet boxes (61), and the end openings of the air outlet boxes (62) face a side of the exhaust device (2).

5. A hot air supply device for a low-temperature circulating grain dryer according to claim 4, characterized in that: A plurality of air dispersion holes (611) are provided on the surface of the air inlet box (61), and the cross-sectional area of ​​the air inlet box (61) gradually decreases along the air inlet channel (4) towards the exhaust device (2); the cross-sectional area of ​​the air outlet box (62) gradually decreases along the air inlet channel (4) towards the exhaust device (2), and a flow guide component (621) is provided in the air outlet box (62).

6. A hot air supply device for a low-temperature circulating grain dryer according to claim 5, characterized in that: The air dispersion holes (611) are conical holes, the end with a larger hole diameter faces the inside of the air inlet box (61), and the number of the air dispersion holes (611) decreases along the direction in which the cross-sectional area of ​​the air inlet box (61) decreases.

7. The hot air supply device for a low-temperature circulating grain dryer according to claim 5, characterized in that: The flow guide assembly (621) comprises a flow guide rotating shaft (6211) and a plurality of flow guide impellers (6212); the flow guide rotating shaft (6211) is installed inside the air outlet box (62); a plurality of flow guide impellers (6212) are arranged in a linear array on the flow guide rotating shaft (6211), and an adsorption layer (6213) is arranged on the surface of each flow guide impeller (6212).

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