Hot air supply device for low-temperature circulating grain dryer

Abstract

The invention relates to the technical field of grain drying equipment, in particular to a hot air supply device for a low-temperature circulating grain dryer, which comprises an air inlet channel, an air supply device and an angular box, the air inlet channel comprises a tempering channel, a drying channel and a cooling channel; the tempering channel is connected with the upper layer of the tower body; the drying channel is connected with the tower body middle layer; the cooling channel is connected with the lower layer of the tower body; the air supply device is connected with the air inlet channel; the angular box is connected with the tower body; a hot air inlet channel is divided into three layers, the flow speed of hot air in the middle layer is the highest, the circulation area of a drying channel can be automatically reduced along with the increase of the humidity of the exhaust side, the air inlet speed of dry hot air is higher, moisture can be rapidly taken away, the number of horn-shaped boxes for exhaust is larger than that of horn-shaped boxes for air inlet, and the air exhaust amount in unit time is increased; the problem that the drying effect on the side close to an exhaust channel is poor due to the fact that the humidity of the hot air inlet side of the drying chamber is low and the humidity of the exhaust side is high is solved.

Description

Technical Field

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

[0002] Low-temperature circulating grain dryer is a kind of equipment specially used for drying grains. It mainly evaporates moisture in grains by heating air to 40 to 70 degrees Celsius and then sending hot air into the drying chamber through the air supply device. The air supply device of the grain dryer needs to divide the hot air into multiple layers and discharge it evenly to the surface of the grain to avoid uneven heating of the grain and cause it to be scorched or insufficiently dried.

[0003] The hot air supply device of the grain dryer usually uses a fan to send the air heated in the heating system into the air supply duct, and the air supply duct then sends the air into the angular box in the drying chamber, and flows out from the angular box to the surface of the grain, so that the hot air is evenly distributed on the surface of the grain; however, since the hot air continuously flows into the angular box from the side wall of the drying chamber, heat accumulation will occur at the side wall of the drying chamber, causing the grain near the side wall to burn due to overheating. The prior art has proposed a good solution to this problem, such as a downstream tower grain dryer with patent publication number CN104776704B. By setting the isolation of the upper baffle and the lower baffle, the hot air will not contact the side wall of the drying chamber, thereby avoiding the high temperature hot air causing the side wall of the drying chamber to be too high and causing the grain to overheat and burn, thereby ensuring the drying effect of the grain.

[0004] Although the existing technology has solved the problem of heat accumulation at the side wall due to hot air entering from the side wall of the drying chamber, causing the grain at the side wall to overheat and burn, the following problems still exist: after the dry hot air enters the angular box with an opening toward the air inlet channel, it will diffuse from the bottom of the angular box to the surface of the grain, and after taking away the moisture in the grain, it will enter the angular box with an opening toward the exhaust channel, carrying a large amount of moisture and accumulating at the exhaust channel. At this time, the humidity on the side where the hot air enters the drying chamber will be low, and the humidity on the side where the hot air is discharged will be high, resulting in insufficient drying of the grain near the exhaust channel, resulting in unsatisfactory grain drying effect, especially when used in winter, when the outside temperature is low, the moisture in the humid hot air on one side of the exhaust channel will be more likely to condense, thereby causing the grain drying effect on the exhaust channel side to further decrease.

[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 of the hot air entering the drying chamber is low and the humidity of the exhausting chamber is high, resulting in poor grain drying effect on the side close to the exhaust passage. The hot air inlet passage is divided 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 dry hot air intake speed faster and able to quickly take away the moisture; at the same time, the angular box is designed to have a shape with a gradually decreasing flow area along the direction from the air intake to the exhaust, and the number of angular boxes for exhaust is more than that for intake, so as to increase the exhaust volume per unit time, ensure that the humidity in the drying chamber is controlled within an allowable range, and ensure 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 comprises a tower body, an exhaust device and a feeding device, and also comprises an air inlet channel, an air supply device and an angle box; the air inlet channel comprises a slow-release channel, a drying channel and a cooling channel; the slow-release channel is connected to the upper layer of the tower body; the drying channel is connected to the middle layer of the tower body, and when the humidity in the tower body near one end of the exhaust device rises, the drying channel contracts to reduce the flow area and accelerate the flow rate of hot air; the cooling channel is connected to the lower layer of the tower body; the air supply device is connected to the air inlet channel, and when the air supply device is working, it supplies hot air into the slow-release channel, the drying channel and the cooling channel; the angle box comprises an air inlet box and an air outlet box; the air inlet box is connected to the tower body and communicated with the air inlet channel; the air outlet box is connected to the tower body and communicated with the exhaust device, and the hot and humid air radially enters the air outlet box and then flows axially and flows to the exhaust device.

[0009] Preferably, an upper partition plate is provided between the slow cooling channel and the drying channel; a lower partition plate is provided between the drying channel and the cooling channel; and an angle formed by the extension lines of the upper partition plate and the lower partition plate is oriented toward the air inlet channel.

[0010] In the above scheme, this arrangement can make the hot air circulation area of ​​the drying channel gradually decrease, while the flow rate of the hot air is constant. At this time, the flow rate of the hot air will be increased. Since the drying process of grains is divided into three steps of slow thawing, drying and cooling, the most water evaporates during the drying process, so the flow rate of the hot air needs to be high during the drying process to take away all the water, thereby avoiding the influence of humidity on the drying effect; and because the flow area of ​​the slow thawing channel and the cooling channel will increase under the action of the partition upper plate and the partition lower plate, thereby slowing down the flow rate of the hot air, making the temperature rise slowly in the slow thawing and cooling stages, ensuring that water can evaporate slowly in these two stages, avoiding cracking and coking of the grains.

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

[0012] In the above scheme, air is sent into the air inlet channel by the air supply fan, and the air supply fan is facing the drying channel, which can make the hot air flow rate in the drying channel higher and the flow rate larger, while the amount of hot air entering the slow cooling channel and the cooling channel is less and slower than that in the drying channel, thereby better helping the grains to undergo a process of gradually increasing and then gradually decreasing temperature, thereby ensuring a better grain drying effect; and under the action of the connecting seat, the ventilation speed of the drying channel can be automatically changed, thereby better removing moisture.

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

[0014] In the above scheme, when the humidity is high, the expansion rubber will absorb moisture in the hot air and expand, and because the expansion rubber is not located in the air outlet box but in the grain, it can absorb moisture close to the exhaust channel when absorbing moisture. On the other hand, when the humidity is too high and the amount of moisture absorbed is large, it will push the connecting seat to make the angle formed by the partition upper plate and the partition lower plate smaller. At this time, the hot air intake speed will further increase, increasing the circulation speed of the hot air, thereby taking away the moisture. When the humidity is low, keeping the hot air intake speed moderate can save hot air loss and avoid too fast hot air circulation speed, which causes the hot air to be discharged from the tower too early and leads to too low heat utilization rate.

[0015] Preferably, the air inlet boxes are arranged in a linear array in the horizontal direction inside the tower body, and the openings of the air inlet boxes face the air inlet channel. Multiple rows of air inlet boxes are arranged in the vertical direction, and the distance between each row of air inlet boxes first decreases and then increases from the upper layer of the tower body to the lower layer of the tower body; the air outlet boxes are arranged in multiple rows like the air inlet boxes, and the air boxes in each row are spaced apart from each row of air inlet boxes, and the number of rows and columns of air outlet boxes is more than that of air inlet boxes, and the openings of the air outlet boxes face the side of the exhaust device.

[0016] In the above scheme, the density of hot air entering is controlled to first decrease and then increase in the direction from the upper layer of the tower body to the lower layer of the tower body, so as to ensure that the temperature in 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, and the temperature difference between the inside and outside of the grains is balanced, so that the moisture can diffuse evenly from the inside to the outside, and then the high temperature directly acts on the grains to cause the surface to be coked, and the gradual heating and cooling process helps the grain drying process to be more uniform, and the moisture in each part of the grains can be evaporated under relatively balanced conditions, reducing quality problems caused by uneven drying; on the other hand, due to the large number of air inlet boxes and air outlet boxes in the middle layer, the circulation area of ​​the hot air can be increased, and the hot air can circulate quickly in the middle layer and take away the moisture, avoiding excessive humidity on one side of the tower exhaust device; and because the number of rows and columns of the air outlet boxes is more than the air inlet boxes, the outflow end area of ​​the humid hot air can be increased, thereby helping the humid hot air to be discharged quickly and further reducing the humidity on one side of the exhaust device.

[0017] Preferably, a plurality of air dispersion holes are provided on the surface of the air inlet box, and the cross-sectional area of ​​the air inlet box gradually decreases along the air inlet channel toward the exhaust device; the cross-sectional area of ​​the air outlet box gradually decreases along the air inlet channel toward the exhaust device, and a guide component is arranged inside the air outlet box.

[0018] In the above scheme, the air diffusion holes on the surface of the air inlet box can quickly diffuse the hot air to the surface of the grains, which on the one hand ensures the uniformity of drying, and on the other hand makes the hot air circulate faster, so that the hot air carrying moisture can flow out quickly, avoiding excessive humidity and inadequate drying; the cross-sectional area change of the air outlet box can accelerate the outflow speed of the hot air carrying moisture, and the closer to the exhaust device, the faster its flow speed, so that the moisture can be quickly discharged, avoiding the problem of inadequate drying caused by excessive humidity on one side of the exhaust device; the guide component can make the wind entering the air outlet box flow out quickly along a predetermined path, thereby avoiding moisture accumulation.

[0019] Preferably, the air dispersion holes are conical holes, with the end with a larger aperture facing the inside of the air inlet box, and the number of the air dispersion holes decreases in the direction in which the cross-sectional area of ​​the air inlet box decreases.

[0020] In the above scheme, the conical holes can make the hot air diffuse when discharged, so that the hot air distribution is more even. As the cross-sectional area of ​​the air inlet box gradually decreases, the wind speed can gradually increase. Since the number of air diffusion holes decreases in the direction of decreasing cross-sectional area of ​​the air inlet box, the amount of hot air outflow on both sides of the air inlet and outlet of the drying chamber can be controlled to be balanced, thereby avoiding uneven distribution of hot air on both sides due to fast flow rate on one side and slow flow rate on the other side, and then resulting in different drying effects on both sides.

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

[0022] In the above scheme, after the hot and humid air enters the air outlet box from the radial direction, it will drive the guide vane to rotate. When the guide vane rotates, the movement direction of the hot and humid air will change from radial to axial, and in conjunction with the exhaust device, the hot and humid air can be quickly discharged from the air inlet box to avoid excessive humidity; and when the hot and humid air passes through the surface of the guide vane, the moisture in it will be absorbed by the adsorption layer, thereby achieving the purpose of reducing the humidity.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Compared with the existing grain dryer, the present invention sets a slow-drying 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 toward the air supply fan, the hot air flow area of ​​the drying channel gradually decreases along the air intake direction, and the flow areas of the slow-drying channel and the cooling channel gradually increase along the air intake direction, which can increase the hot air flow rate of the middle drying layer, thereby helping the evaporated moisture to be quickly taken away, while the flow rates of the upper and lower layers are relatively slow, so that the grains can evaporate slowly, avoiding the grains from being suddenly subjected to high temperatures and cracking and coking; the upper partition plate and the lower partition plate will reduce the angle between the two under the action of the connecting seat as the humidity increases, and the hot air intake speed will be further increased at this time, so as to achieve a moderate intake speed when the humidity is low to avoid excessive heat energy loss, and a faster intake speed when the humidity is high, so that the hot air flow rate is higher and the moisture can be taken away faster, avoiding unsatisfactory grain drying effect caused by excessive humidity.

[0025] 2. The present invention arranges 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, thereby ensuring the humidity balance between the air inlet side and the air outlet side, and further ensuring the drying effect. In addition, with the arrangement design in which the number of air outlet boxes is greater than the air inlet boxes, the total area of ​​the air outlets of all the air outlet boxes can be equal to the total area of ​​the air inlet ports of all the air inlet boxes, thereby maintaining the balance between the air intake and air outlet, ensuring that the hot and humid air on the air outlet side can be discharged smoothly and quickly, and further ensuring a good grain drying effect on the side close to the exhaust device.

[0026] 3. The present invention provides a guide vane in the air outlet box, so that when the hot and humid air enters the air outlet box from the radial direction, the guide vane can be driven to rotate. When the guide vane rotates, the flow direction of the hot and humid air will change from radial to axial. At this time, the hot and humid air will flow out quickly, avoiding the accumulation of moisture in the tower body and causing unsatisfactory drying effect. In addition, an adsorption layer is provided on the surface of the guide vane, which can absorb part of the moisture when the hot and humid air passes through the surface of the guide vane. When the humidity is too high, the humidity can be quickly controlled within an appropriate range through the adsorption effect of the adsorption layer. When the humidity increases, the flow area of ​​the drying channel is reduced and the hot air intake speed is increased. The guide vane can rotate faster under the action of the rapid flow of gas, so that the adsorption layer is fully in contact with the hot and humid air, thereby improving the adsorption effect and ensuring the grain drying effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

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

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

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

[0032] Figure 5 It is a cross-sectional view of the expansion assembly of the present invention;

[0033] Figure 6 It is a structural diagram of the air inlet box of the present invention;

[0034] Figure 7 It is a structural diagram of the air outlet box of the present invention;

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

[0036] In the figure: 1. tower body; 2. exhaust device; 3. feeding device; 4. air inlet channel; 41. slow recovery channel; 42. drying channel; 43. cooling channel; 44. partition upper plate; 45. partition lower plate; 5. air supply device; 51. air supply fan; 52. fixed shaft; 53. connecting swivel seat; 54. expansion component; 541. sliding cavity; 542. expansion rubber; 543. connecting push rod; 544. adjusting spring; 6. angular box; 61. air inlet box; 611. air dispersion hole; 62. air outlet box; 621. guide component; 6211. guide shaft; 6212. guide impeller; 6213. adsorption layer. DETAILED DESCRIPTION

[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 and specific implementation methods.

[0038] See also 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 embodiment 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, comprising a tower body 1, an exhaust device 2 and a feeding device 3, and also comprising an air inlet channel 4, an air supply device 5 and an angle box 6; the air inlet channel 4 comprises a slow-release channel 41, a drying channel 42 and a cooling channel 43; the slow-release 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 near one end of the exhaust device 2 in the tower body 1 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 is working, the hot air is sent into the slow cooling 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 is connected to the air inlet channel 4; the air outlet box 62 is connected to the tower body 1, and is connected to the exhaust device 2. After the humid hot air radially enters the air outlet box 62, it flows axially and flows to the exhaust device 2, thereby 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 embodiment of the present invention, refer to Figure 3 and Figure 4; An upper partition plate 44 is provided between the slow drying channel 41 and the drying channel 42; a lower partition plate 45 is provided between the drying channel 42 and the cooling channel 43; the angle formed by the extension lines of the upper partition plate 44 and the lower partition plate 45 is toward the side of the air inlet channel 4. This arrangement can make the hot air circulation area of ​​the drying channel 42 gradually decrease, while the flow rate of the hot air is constant. At this time, the flow rate of the hot air will be increased. Since the drying process of grains is divided into three steps of slow drying, drying and cooling, the most water evaporates during the drying process, so it is necessary to ensure that the flow rate of hot air is high during the drying process to take away all the water, thereby avoiding the influence of humidity on the drying effect; and because the slow drying channel 41 and the cooling channel 43 will form an increased circulation area under the action of the upper partition plate 44 and the lower partition plate 45, thereby slowing down the flow rate of the hot air, so that the temperature rises slowly in the slow drying and cooling stages, ensuring that the water can evaporate slowly in these two stages, avoiding the 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 supplied to the air inlet channel 4 through the air supply fan 51, and the air supply fan 51 is facing the drying channel 42, which can make the hot air flow rate in the drying channel 42 higher and larger, and the amount of hot air entering the slow cooling channel 41 and the cooling channel 43 is less and slower than that in the drying channel 42, so as to better help the grains to gradually increase and then gradually decrease in temperature, thereby 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 remove moisture.

[0042] As a specific embodiment of the present invention, refer to Figure 5The expansion component 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 expansion rubber 542 is made of water-expandable rubber. These rubber materials contain a high proportion of hydrophilic groups, which can combine with water molecules and absorb moisture to cause expansion. However, due to their high viscosity and polymer structure, moisture will not flow out easily, especially in the case of squeezing. When the air outside the expansion rubber 542 becomes dry hot air, The moisture therein will be slowly taken away by the dry hot air. At this time, on the one hand, it can prevent the moisture from flowing out of the expansion rubber 542 and affecting the drying of the grains. On the other hand, when the dry hot air flows rapidly on the exhaust side and slowly takes the moisture out of the expansion rubber 542, the moisture accumulated in the expansion rubber 542 can be used to evaporate and absorb excessive heat to prevent the grains on the exhaust side from heating up quickly and causing scorching, and the expansion rubber 542 can be reused repeatedly. The connecting push rod 543 is connected between the expansion rubber 542 and the connecting swivel seat 53; the adjusting spring 544 is connected between the connecting push rod 543 and the sliding cavity 541. When the humidity is high, the expansion rubber 542 will absorb moisture in the hot air and expand. Since the expansion rubber 542 is not located in the air outlet box 62 but in the grain, it can absorb moisture close to the exhaust channel when absorbing moisture. On the other hand, when the humidity is too high and the amount of moisture absorbed is large, it will push the connecting seat 53 to make the angle formed by the partition upper plate 44 and the partition lower plate 45 smaller. At this time, the hot air intake speed will further increase, increasing the circulation speed of the hot air, thereby taking away the moisture. When the humidity is low, maintaining a moderate hot air intake speed can save hot air loss and avoid too fast hot air circulation speed. The tower body 1 is discharged too early, resulting in low heat utilization rate.

[0043] As a specific embodiment of the present invention, refer to Figure 4 and Figure 5The air inlet boxes 61 are arranged in a linear array in 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 in the vertical direction, and the distance between each row of air inlet boxes 61 first decreases and then increases 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 spaced apart 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 openings of the air outlet boxes 62 face the side of the exhaust device 2. By controlling the density of hot air entering to first decrease and then increase in the direction from the upper layer of the tower body 1 to the lower layer of the tower body 1, it is ensured that the temperature in 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 between the inside and outside of the grains, so that the moisture can diffuse evenly from the inside to the outside, and then the high temperature directly acts on the grains to cause the surface to be coked, and the gradual heating and cooling process helps the grain drying process to be more uniform, and the moisture in each part of the grains can be evaporated under relatively balanced conditions, reducing quality problems caused by uneven drying; on the other hand, due to the large number of air inlet boxes 61 and air outlet boxes 62 in the middle layer, the circulation area of ​​the hot air can be increased, and the hot air can circulate quickly in the middle layer and take away the moisture, avoiding excessive humidity on one side of the exhaust device of the tower body 1; and because the number of rows and columns of the air outlet boxes 62 is more than the air inlet boxes 61, the outflow end area of ​​the humid hot air can be increased, thereby helping the humid hot air to be discharged quickly and further reducing the humidity on one side of the exhaust device.

[0044] As a specific embodiment of the present invention, refer to Figure 5 , Figure 6 and Figure 7 ; The surface of the air inlet box 61 is provided with a plurality of air dispersion holes 611, and the cross-sectional area of ​​the air inlet box 61 gradually decreases along the air inlet channel 4 toward the exhaust device 2; the cross-sectional area of ​​the air outlet box 62 gradually decreases along the air inlet channel 4 toward the exhaust device 2, and a flow guide component 621 is arranged in the air outlet box 62. The air dispersion holes 611 on the surface of the air inlet box 61 can quickly diffuse the hot air to the surface of the grains, which can ensure the uniformity of drying on the one hand, and make the hot air flow faster on the other hand, so that the hot air carrying moisture can flow out quickly, avoiding excessive humidity and inadequate drying; the change of the cross-sectional area of ​​the air outlet box 62 can accelerate the outflow speed of the hot air carrying moisture, and the closer to the exhaust device 2, the faster its flow speed, so that the moisture can be quickly discharged, avoiding the problem of inadequate drying caused by excessive humidity on one side of the exhaust device 2; the flow guide component 621 can make the wind entering the air outlet box 62 flow out quickly along a predetermined path, so as to avoid moisture accumulation.

[0045] As a specific embodiment of the present invention, refer to Figure 6The air dispersion holes 611 are conical holes, with the end with a larger aperture facing the inside of the air inlet box 61, and the number of the air dispersion holes 611 decreases along the direction of decreasing cross-sectional area of ​​the air inlet box 61. The conical holes can make the hot air diffuse when discharged, so that the hot air is more evenly distributed, and the wall surface of the air inlet box 61 can be thickened, and a heat insulation layer is arranged inside it, so as to avoid the high heat conduction efficiency of the air inlet box 61, which causes the grains on the surface of the air inlet box 61 to be scorched, and the increase in the thickness of the air inlet box 61 can deepen the depth of the air dispersion holes 611, so that the air dispersion holes 611 can effectively pressurize and diffuse the gas out, and the wind speed can be gradually increased due to the gradual decrease in cross-sectional area of ​​the air inlet box 61; since the number of the air dispersion holes 611 decreases along the direction of decreasing cross-sectional area of ​​the air inlet box 61, the amount of hot air outflow on both sides of the air inlet and outlet of the drying chamber can be controlled to be balanced, so as to avoid uneven distribution of hot air on both sides due to fast flow rate 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 guide assembly 621 includes a guide shaft 6211 and a plurality of guide impellers 6212; the guide shaft 6211 is installed inside the air outlet box 62; a plurality of guide impellers 6212 are linearly arrayed on the guide shaft 6211, and the guide impeller 6212 is an axial flow impeller capable of converting radial flow into axial flow, and an adsorption layer 6213 is provided on the surface of each guide impeller 6212. After the humid hot air enters the air outlet box 62 from the radial direction, it will drive the guide impeller 6212 to rotate. When the guide impeller 6212 rotates, the movement direction of the humid hot air will be changed from radial to axial. In conjunction with the exhaust device 2, the humid hot air can be quickly discharged from the air inlet box 61 to avoid excessive humidity. When the humid hot air passes through the surface of the guide impeller 6212, the moisture therein will be absorbed by the adsorption layer 6213, thereby achieving the purpose of reducing the humidity. When the humidity increases, the flow area of ​​the drying channel 42 is reduced, and the hot air intake speed is increased, which can make the guide impeller 6212 rotate faster under the action of the rapid flow of gas, so that the adsorption layer 6213 is fully in contact with the humid hot air, thereby improving the adsorption effect and ensuring the grain drying effect.

[0047] Working process: under the action of the air supply fan 51, the hot air enters the air inlet box 61 from the slow cooling 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 enters the air outlet box 62 from the radial direction. In the air outlet box 62, the flow direction of the humid hot air becomes axial and part of the moisture therein will be absorbed. At the same time, as the flow area of ​​the air outlet box 62 is reduced, the humid hot air will be discharged faster to avoid excessive humidity on the exhaust side.

[0048] Specifically, under the action of the air supply fan 51, the hot air is sent into the slow-heating channel 41, the drying channel 42 and the cooling channel 43. In order to achieve the temperature change of the grains in the drying process to gradually increase and then decrease to ensure the drying effect of the grains, the angle formed between the partition upper plate 44 and the partition lower plate 45 is used to gradually reduce the flow area of ​​the drying channel 42 along the air inlet direction, thereby accelerating the hot air passing through the drying channel 42. On the contrary, the flow areas of the slow-heating channel 41 and the cooling channel 43 along the air inlet direction are gradually increased. At this time, the hot air entering the slow-heating channel 41 and the cooling channel 43 will be decelerated, thereby ensuring that the grains are gradually heated up after entering the tower body 1, avoiding the grains being directly subjected to high temperature, resulting in rapid evaporation of the surface moisture of the grains while the internal moisture cannot evaporate, thereby causing scorching.

[0049] During the drying stage, the most moisture evaporated from the grains. At this time, the humid hot air is discharged from the exhaust device 2, resulting in excessive humidity on the exhaust side of the tower body 1. In order to prevent the excessive humidity on the exhaust side of 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 moisture in the humid hot air. The expansion rubber 542 absorbs moisture and expands, pushing the connecting push rod 543 to push the connecting rotating seat 53 to reduce the angle formed between the partition upper plate 44 and the partition 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 dry hot air will be further increased, and the dry hot air will quickly take away the humid hot air, thereby ensuring that the humidity in the tower body 1 is controlled within an appropriate range; when the dry hot air enters the air inlet box 61, the 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 close to the exhaust device 2 will have a faster flow rate, thereby avoiding the accumulation of humid hot air and causing humid The hot air in the air inlet box 61 flows out from the air diffusion holes 611 and the bottom of the air inlet box 61 to the surface of the grains, and the dry hot air flowing out from the air diffusion holes 611 will form a diffuse spray, so that the grains can be heated evenly. After the dry hot air evaporates the moisture in the grains, it will become humid hot air and enter the air outlet box 62 from the radial direction. At this time, the humid hot air will cause the guide impeller 6212 to rotate. Under the action of the blades of the guide impeller 6212, the humid hot air will change from radial flow to axial flow, so that the humid hot air is quickly discharged from the tower body 1, and the faster the intake speed of the dry hot air, the higher the flow rate of the humid hot air will be. The faster the humid hot air enters the air outlet box 62, the faster the speed at which the humid hot air enters the air outlet box 62, the rotation speed of the guide impeller 6212 will increase, and the adsorption layer 6213 on the guide impeller 6212 will be in more sufficient contact with the humid hot air, so that excessive moisture is absorbed into the adsorption layer 6213, which helps to quickly reduce the humidity inside the tower body 1, and further ensure 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 should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected, and the scope of the present invention to be protected is defined by the attached 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) and then flows axially to the exhaust device (2).

2. A hot air supply device for a low-temperature circulating grain dryer according to claim 1, characterized in that: 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).

3. A hot air supply device for a low-temperature circulating grain dryer according to claim 2, 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).

4. A hot air supply device for a low-temperature circulating grain dryer according to claim 3, 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).

5. 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).

6. A hot air supply device for a low-temperature circulating grain dryer according to claim 5, 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).

7. A hot air supply device for a low-temperature circulating grain dryer according to claim 6, 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.

8. The hot air supply device for a low-temperature circulating grain dryer according to claim 6, 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).

Images