grain dryer

Abstract

To provide a grain dryer capable of particularly preventing corn from being damaged, while maintaining the capability of drying unhulled rice and soybeans.SOLUTION: When corn is set as the kind of grain to be dried, by setting means 41 of setting the kind of grain to be dried by a grain dryer 1, gap adjustment means 14 adjusts the width of an interference prevention gap G1 formed between a delivery valve 8 and the bottom end of a downflow path 3b1 to be wider than that when unhulled rice is set as the kind of grain to be dried, and to be narrower than that when soybeans are set, and valve rotation speed adjustment means 2, 12 of adjusting the valve rotation speed of the delivery valve 8 adjust the rotation speed of the delivery valve to be lower than that when unhulled rice is set as the kind of grain to be dried, and to be equal to or higher than that when soybeans are set.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a grain dryer capable of drying grains, particularly paddy, soybeans, and corn.

Background Art

[0002] Conventionally, there is known a grain dryer capable of drying the entire amount of grains by circulating the grains up and down and applying hot air generated by a burner or the like. For example, Patent Document 1 discloses a grain dryer for drying various grains including paddy, soybeans, corn, etc.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since corn has different properties such as particle size, surface hardness, and moisture content from paddy and soybeans, when dried under the same conditions as paddy and soybeans as in the invention described in Patent Document 1, there is a problem that the surface of the corn grains is damaged during the drying process, leading to a deterioration in quality. Therefore, an object of the present invention is to provide a grain dryer that can dry paddy and soybeans while particularly preventing damage to corn.

Means for Solving the Problems

[0005] This object of the present invention is a grain dryer for drying various grains including paddy, soybeans, and corn, a storage part for storing grains, It has a flow passage for allowing grain to flow down from the storage section, and a drying section for drying the flowing grain by applying hot air, A dispensing valve that receives and dispenses the grains that have flowed down the aforementioned flow passage, A grain collection unit for collecting grains dispensed by the aforementioned dispensing valve, The aforementioned grain collection section includes an elevator that lifts and circulates the collected grain, A seal portion is disposed to cover the lower part of the interference prevention gap formed between the outer circumferential surface of the dispensing valve and the lower end of the flow passage, and is configured to adjust the width dimension of the interference prevention gap by rotational movement, A gap adjustment means for freely adjusting the width dimension of the interference prevention gap by rotating the seal portion, A valve rotation speed adjustment means for adjusting the rotation speed of the aforementioned dispensing valve, It includes a setting means that accepts a predetermined operation from the user and sets the type of grain to be dried, When the type of grain to be dried is set to corn by the setting means, the gap adjustment means adjusts the width dimension of the interference prevention gap to a dimension that is larger than when it is set to rice, and smaller than when it is set to soybeans, This is achieved by a grain dryer characterized in that the valve rotation speed adjustment means is configured to adjust the rotation speed of the dispensing valve to a speed lower than that set for paddy rice, and the same as or higher than that set for soybeans.

[0006] According to the present invention, when the type of grain is set to corn, the interference prevention gap formed between the outer surface of the dispensing valve that dispenses the grains and the lower end of the flow passage is adjusted to a size larger than that for rice and smaller than that for soybeans, according to the size of the grains. This prevents grains from getting caught in the interference prevention gap and prevents the corn kernels from being crushed.

[0007] Furthermore, according to the present invention, when set to corn, the rotation speed of the dispensing valve is adjusted to a lower speed than that for rice and the same or higher speed as that for soybeans, depending on the size and softness of the grains, thereby further preventing damage to the corn due to jamming.

[0008] In a preferred embodiment of the present invention, A lower spiral is provided in the grain collection section and transports the grain dispensed by the dispensing valve to the elevator. The system includes a lower spiral position changing means that can adjust the distance between the lower spiral and the bottom surface of the grain collection section by changing the vertical position of the lower spiral, When the setting means is set to corn, the lower spiral position changing means is configured to adjust the spacing to be wider than when it is set to rice, and the same as when it is set to soybeans, or narrower than when it is set to soybeans.

[0009] According to this preferred embodiment of the present invention, when set for corn, the distance between the lower spiral and the bottom surface of the grain collection section is adjusted to be wider than that for paddy grains, and the same as or narrower than that for soybeans, depending on the size and softness of the grains, thereby preventing damage to the corn during transport by the lower spiral.

[0010] In a preferred embodiment of the present invention, An upper spiral receives the grains that have been lifted and transported by the elevator and transports them to a position above the approximate center of the storage section in a plan view, A diffusion plate is positioned near the end of the upper spiral conveying section and diffuses the grains conveyed by the upper spiral within the storage section. The upper spiral provides a dropping mechanism that causes the grains being transported to fall before they are diffused by the diffusion plate, The system includes elevator rotation speed adjustment means for adjusting the rotation speed of the elevator, which is composed of a bucket elevator, When the setting means is set to rice grains, the grains are diffused into the storage section by the diffusion plate. In contrast, when the setting means is set to corn or soybeans, the grains are dropped by the dropping mechanism, and the elevator rotation speed adjustment means is configured to adjust the rotation speed of the elevator to a lower speed than when it is set to rice grains.

[0011] According to this preferred embodiment of the present invention, when set to corn or soybeans, the grains are dropped into the storage section by the dropping mechanism without being diffused by the diffusion plate, thus preventing damage from contact with the diffusion plate.

[0012] Furthermore, when set to corn or soybeans, the rotational speed of the elevator, which is composed of bucket elevators, is adjusted to be lower than when set to rice, thus preventing damage to the grains when they are transferred from the elevator to the upper spiral.

[0013] In a preferred embodiment of the present invention, A moisture meter that grinds grains and measures the moisture content of the grains, A guide member that receives the grains that fall from the elevator one by one and guides them to the moisture meter, The system includes a receiving dimension adjustment means for adjusting the particle size of grains that can be accepted by the guide member by changing the width of the guide member, When the setting means is set to corn, the receiving dimension adjustment means is configured to adjust the width of the guide member to be larger than when it is set to rice, and the same as or smaller than when it is set to soybeans.

[0014] According to this preferred embodiment of the present invention, the receiving width of the guide member that leads to the moisture meter for detecting the moisture content of grains can be adjusted according to the type of grain set, so that the moisture meter can be used universally for various types of grains and manufacturing costs can be reduced.

[0015] In a preferred embodiment of the present invention, It is equipped with a burner that generates hot air for grains, Using the setting means, regardless of whether it is set to paddy, soybean, or corn, the higher the amount of grains loaded, the higher the set temperature of the burner. At the same time, When it is set to corn using the setting means, the set temperature of the burner for the same loading amount is lower than when it is set to paddy, and is the same as or higher than the temperature when it is set to soybean.

[0016] According to this preferred embodiment of the present invention, under the condition of the same loading amount, the set temperature of the burner in the case of corn is set lower than that in the case of paddy. Therefore, the generation of wrinkles on the surface of corn grains can be suppressed, and the wrinkles of corn are not as likely to occur as those of soybeans. Therefore, by setting the temperature higher than that of soybeans, the generation of wrinkles can be suppressed while accelerating drying. In a preferred embodiment of the present invention, The downward flow passage is formed by a drying net through which the hot air generated by the burner passes, and the grain dryer is equipped with an air volume adjusting means for adjusting the air volume passing through the drying net. When it is set to corn using the setting means, the air volume adjusting means is configured to adjust the air volume to be larger than when it is set to paddy.

[0017] According to this preferred embodiment of the present invention, when it is set to corn, the air volume passing through the drying net is adjusted to be larger than when it is set to paddy. Therefore, by increasing the air volume while suppressing the set temperature of the burner, the drying of corn can be accelerated.

[0018] In a preferred embodiment of the present invention, A noise meter is arranged in the case part connecting the elevator and the upper spiral, When the magnitude of the noise measured by the noise meter is equal to or greater than a preset reference value, the drying operation of the grains is configured to be stopped, and the reference value can be changed.

[0019] Compared to soybeans and other grains, corn tends to have a larger moisture content difference between the center and the outer part of the grain. Therefore, it can be difficult to accurately measure the moisture content of corn kernels using a moisture meter. However, according to this preferred embodiment of the present invention, by measuring the noise during corn transport, the drying of the corn can be accurately detected based on the magnitude of the noise associated with the increase in hardness of the corn kernels, and drying can be stopped at the appropriate time. In addition, by making the reference value adjustable, it is possible to accommodate differences in corn varieties and grades. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a grain dryer that can dry rice and soybeans while preventing damage to corn in particular. [Brief explanation of the drawing]

[0021] [Figure 1] Figure 1 is a schematic front view of a grain dryer according to a preferred embodiment of the present invention. [Figure 2] Figure 2 is a schematic right side view of the grain dryer shown in Figure 1. [Figure 3] Figure 3 is a longitudinal cross-sectional view showing the inside of the drying tank shown in Figure 1. [Figure 4] Figure 4 is a partial longitudinal cross-sectional view of the vicinity of the dispensing valve shown in Figure 3. [Figure 5] Figure 5 is an enlarged partial longitudinal cross-sectional view of the vicinity of the dispensing valve shown in Figure 4. [Figure 6] Figure 6 is an enlarged perspective view showing the area near the lower spiral shown in Figure 3. [Figure 7] Figure 7 is a schematic perspective view showing the circulating mechanism for grains. [Figure 8] Figure 8 is a graph showing the relationship between the amount of grain invested and the amount of grain circulated for each type of grain. [Figure 9] Figure 9 is a schematic perspective view showing the moisture measurement unit that detects the moisture content of grains. [Figure 10]Figure 10 is an enlarged perspective view of the vicinity of the upper helix shown in Figure 1. [Figure 11] Figure 11 is an enlarged perspective view of the vicinity of the diffusion plate located at the top of the drying tank shown in Figure 1. [Figure 12] Figure 12 is a schematic plan view of the grain dryer shown in Figure 1. [Figure 13] Figure 13 is an exploded perspective view of the dust collector shown in Figure 12. [Figure 14] Figure 14 is a partial longitudinal cross-sectional view showing the exhaust air circulation mechanism installed near the exhaust fan. [Figure 15] Figure 15 is a graph showing the relationship between the amount of grain loaded for each type of grain and the proportion of hot air that is recirculated into the drying tank. [Figure 16] Figure 16 is a control block diagram of the grain dryer shown in Figure 1. [Figure 17] Figure 17 is a graph showing the relationship between the amount of grain loaded and the burner set temperature for each type of grain. [Figure 18] Figure 18 is a graph showing the relationship between the amount of grain loaded for each type of grain and the amount of air passing through the inner and outer drying nets due to the operation of the exhaust fan. [Modes for carrying out the invention]

[0022] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0023] Figure 1 is a schematic front view of a grain dryer 1 according to a preferred embodiment of the present invention, and Figure 2 is a schematic right side view of the grain dryer 1 shown in Figure 1. Figure 3 is a longitudinal cross-sectional view showing the inside of the drying tank shown in Figure 1. Hereinafter, the grain dryer 1 will also be simply referred to as the "machine body".

[0024] The grain dryer 1 comprises a drying tank 3 for drying grain, an elevator 4 for lifting and conveying grain, a lower spiral 6 for conveying and supplying grain located at the bottom of the drying tank 3 to the elevator 4, a burner 5 for generating drying hot air inside the drying tank 3, an upper spiral 7 for receiving grain lifted and conveyed by the elevator 4 and returning it to the drying tank 3, a supply hopper 10 connected to the bottom of the elevator 4 for supplying grain to the machine body 1, an exhaust fan 9 for discharging moist hot air from the drying tank 3 to the outside of the machine body 1, a control device 2 for controlling the entire machine body 1, and a setting unit 11 used by the user to input and set information such as the type of grain to be dried into the control device 2. The control device 2 is located on the front side of the drying tank 3 in Figure 1. In this specification, the side of the control device 2 (front side in the drawing) relative to the drying tank 3 is referred to as "front," the opposite side as "rear," the left side when facing forward is referred to as "left," and the opposite side as "right." The grain dryer 1 of this embodiment is capable of drying grains such as rice, soybeans, and corn.

[0025] The drying tank 3 comprises a storage section 3a for storing grain, a drying section 3b for drying the grain flowing down from the storage section 3a by blowing hot air onto it, and a grain collection section 3c for collecting the grain dispensed by a dispensing valve 8 located at the bottom of the drying section 3b.

[0026] As shown in Figure 3, the drying section 3b has a flow passage 3b1 through which grain flows down from the storage section 3a above. The flow passage 3b1 is formed by an inner drying net 15 and an outer drying net 16 through which hot air generated by the burner 5 passes. The hot air generated by the burner 5 crosses the inner drying net 15 and the outer drying net 16 from left to right and is then discharged to the outside by an exhaust fan 9 located on the rear side (=rear) of the machine body 1. The exhaust fan 9 is rotationally driven by an exhaust fan motor 9a shown in Figure 14.

[0027] Figure 4 is a partial longitudinal section view of the vicinity of the dispensing valve 8 shown in Figure 3, and Figure 5 is an enlarged partial longitudinal section view of the dispensing valve 8 and its vicinity to the left, as shown in Figure 4. Figure 6 is an enlarged perspective view showing the vicinity of the lower helix 6 shown in Figure 3 exposed. Figure 7 is a schematic perspective view showing the circulation mechanism for circulating grain.

[0028] The dispensing valve 8 has a roughly C-shape in a longitudinal cross-section and is equipped with an opening 8a that receives grain flowing down through the flow passage 3b1 and a rotating shaft 8b that extends in the front-to-back direction at the center of the front view. This rotating shaft 8b is driven by the valve drive motor 8c shown in Figure 7, and as the dispensing valve 8 rotates in forward and reverse directions, grain that has entered the valve from the flow passage 3b1 when the opening 8a is facing the flow passage 3b1 (see Figure 5) is dispensed into the grain collection section 3c when the opening 8a is facing downwards (see Figure 4).

[0029] Between the outer surface of the dispensing valve 8 and the lower ends of the pair of left and right flow passages 3b1 (more specifically, the lower ends of the pair of left and right drying nets 16), an interference prevention gap G1 is formed to prevent the dispensing valve 8 from interfering with the pair of drying nets 16 when the rotation axis 8b of the dispensing valve 8 is misaligned.

[0030] On the left and right sides of the dispensing valve 8, and directly below the pair of left and right anti-interference gaps G1, are provided a pair of left and right sealing parts 13 that partially cover the lower part of the pair of anti-interference gaps G1 from below, thereby adjusting the width dimension of the anti-interference gaps G1. Each sealing part 13 is fixed to a rotating plate 18 and is configured to rotate integrally with the rotating plate 18 around a pivot point 19. Bolts 17 are attached to the rotating plate 18, and the left and right bolts 17 are driven up and down by the left and right seal rotation motors 14, so that each rotating plate 18 and each sealing part 13 rotate integrally in either forward or reverse direction as shown in Figure 5 as the rotation direction F, thereby freely adjusting the dimensions of the left and right anti-interference gaps G1. The left and right seal rotation motors 14 are an example of the "gap adjustment means" of the present invention.

[0031] Here, the dimensions of the left and right interference prevention gaps G1 are configured to be adjusted to predetermined dimensions according to the type of grain set by a predetermined operation of the grain type setting switch 41 (see Figure 16), which accepts predetermined operations from the user to set the type of grain. When set to corn, the dimensions of the interference prevention gaps G1 are adjusted to predetermined dimensions that are larger than when set to paddy rice and smaller than when set to soybeans, taking into consideration the size of the grain. This prevents corn kernels from getting caught in the left and right interference prevention gaps G1, thereby preventing damage to the kernels.

[0032] In this embodiment, rubber seals 20 are attached to each sealing portion 13 so as to contact the outer surface of the dispensing valve 8, but it is not necessarily required to provide the seals 20.

[0033] The amount of grain dispensed to the grain collection section 3c by the dispensing valve 8 increases or decreases according to the rotational speed of the dispensing valve 8. The rotational speed of the dispensing valve 8 is configured to be adjusted to a predetermined speed according to the type of grain set by operating the grain type setting switch 41. When the type of grain is set to corn, the rotational speed of the dispensing valve 8 is adjusted to a predetermined speed that is lower than the predetermined rotational speed when set to paddy rice, and higher than the speed when set to soybeans, according to the size and softness of the grains. This further prevents corn grains from getting stuck in the interference prevention gap G1. The rotational speed of the dispensing valve 8 when set to corn may be the same as the speed when set to soybeans. In this case as well, the same effect as described above can be obtained.

[0034] Furthermore, when set to corn or soybeans, the valve drive motor 8c is configured to be driven intermittently. This configuration keeps the amount of corn or soybeans dispensed by the dispensing valve 8, i.e., the circulation amount, lower than when set to other grains, as shown in Figure 8. In the case of corn, the circulation amount decreases in stages as the amount of corn loaded decreases.

[0035] The lower helix 6 is located in the grain collection section 3c and is composed of an auger screw. It is rotationally driven by the conveyor motor 21 shown in Figure 7, enabling the grain fed into the grain collection section 3c to be conveyed to the elevator 4. The bottom surface of the grain collection section 3c is composed of left and right plates 3c1, a bottom plate 3c2 located below the lower helix 6, and a connecting plate 3c3 that connects them. The lower helix 6 is suspended from the drying tank 3 so as not to come into contact with the bottom surface of the grain collection section 3c. The front and rear of the lower helix 6 are each provided with a lifting mechanism composed of a rack and pinion, and the vertical position of the lower helix 6 can be changed (= raised and lowered) by driving the helical lifting motor 6a shown in Figure 16. By changing the vertical position of the lower helix 6, the distance between the bottom surface of the grain collection section 3c and the lower helix 6 is adjusted. The lifting mechanism and its helical lifting motor 6a are examples of the "lower helix position changing means" of the present invention.

[0036] Here, the distance between the lower spiral 6 and the bottom surface of the grain collection section 3c (more specifically, the bottom plate 3c2) is configured to be adjusted to a predetermined distance according to the type of grain set by operating the grain type setting switch 41. In other words, the lower spiral 6 is configured to move to a predetermined vertical position according to the set type of grain. When set to corn, the distance between the lower spiral 6 and the bottom surface of the grain collection section 3c is adjusted to be wider than when set to paddy grain, and the same predetermined distance as when set to soybeans, taking into consideration the size and softness of the grain. This prevents damage to the corn due to friction with the bottom plate 3c2 during transport by the lower spiral 6. Alternatively, the distance between the lower spiral 6 and the bottom surface of the grain collection section 3c when set to corn may be adjusted to a predetermined distance narrower than when set to soybeans. This can achieve the same effect as described above. Furthermore, the front and rear of the lower spiral 6 may be screwed to the drying tank 3, respectively, allowing the user to manually adjust the vertical position of the lower spiral 6 by loosening these screws.

[0037] As shown in Figure 7, the elevator 4 is equipped with an endless (closed loop) conveyor belt 4a and numerous buckets 4b attached to the conveyor belt 4a. The conveyor belt 4a is rotationally driven by the conveyor motor 21, enabling the grain received from the lower spiral 6 to be transported upward. The grain transported upward by the elevator 4 is released as if into the starting position of the upper spiral 7 by the rotational inertia of the buckets 4b.

[0038] Here, the rotational speed of the elevator 4, i.e., the rotational speed of the conveyor belt 4a, is configured to be adjusted to a predetermined speed according to the type of grain set by operating the grain type setting switch 41. In this embodiment, when set to corn, the rotational speed of the conveyor belt 4a is lower than when set to paddy rice, and adjusted to the same predetermined speed as when set to soybeans, taking into consideration the softness of the grain. By setting the speed lower than in the case of paddy rice, the impact on the grain when it is transferred from the elevator 4 to the upper spiral 7 can be mitigated, and damage to the corn kernels can be prevented. In addition, a cushioning material to prevent damage to the corn kernels may be provided in the case section 36 (see Figure 10, etc.) that covers and connects the elevator 4 and the upper spiral 7.

[0039] Figure 9 is a schematic perspective view showing the moisture measuring unit 25 for detecting the moisture content of grains. Figure 9(a) is a schematic perspective view showing the entire moisture measuring unit 25. Figure 9(b) is a schematic perspective view of the guide member 25a that guides the grains to the moisture meter 25b. Figure 9(c) is a schematic perspective view showing the moisture meter 25b.

[0040] A moisture measuring unit 25 is connected to the lower part of the elevator 4, which detects the dryness of the grain by measuring the moisture content of the grain. The moisture measuring unit 25 includes a moisture meter 25b that crushes the grain to detect its moisture content, and a guide member 25a that guides the grain falling from the bucket 4b to the moisture meter 25b during upward transport by the elevator 4.

[0041] The guide section 25a comprises a groove 25a1 into which grains falling from the bucket 4b enter and roll, a plate 25a2 with an opening 25a2a connected to the moisture meter 25b, and a guide member 25a3 positioned directly below the plate 25a2 and having a pair of claws 25a3a. Only grains with a particle size smaller than the distance between the pair of claws 25a3a of the guide member 25a3 are received one by one through the opening 25a2a and the pair of claws 25a3a, and fall into the intake path 25b1 shown in Figure 9(c), and are guided into the moisture meter 25b. The width of the guide member 25a3, more specifically the distance between the pair of claws 25a3a, can be adjusted by the claw spacing adjustment motor 26 shown in Figure 16, and this distance is automatically adjusted according to the type of grain set by operating the grain type setting switch 41. When set to corn, the width of the guide member 25a3 is adjusted to a predetermined width that is larger than when set to paddy grains, but the same as when set to soybeans, depending on the grain size. This allows for accurate measurement of the moisture content of corn grains, and enables the moisture measuring unit 25 and its moisture meter 25b to be used universally for at least three types of grains, thereby reducing manufacturing costs. Alternatively, when set to corn, the width of the guide member 25a3 may be adjusted to a predetermined width that is smaller than when set to soybeans. In this case as well, the same effects as described above can be obtained. The claw spacing adjustment motor 26 corresponds to the "acceptance dimension adjustment means" of the present invention, which adjusts the grain size that can be accepted by the guide member 25a3.

[0042] The grains that enter the moisture meter 25b are crushed by the multiple electrode rollers 25b2 of the moisture meter 25b, and their electrical resistance is measured. The measured electrical resistance is converted into a moisture voltage to calculate the moisture value (= moisture content). Preferably, the amount of conversion is changed by a predetermined amount depending on whether the setting is for soybeans or corn. The measurement result from the moisture meter 25b is displayed on the operation display panel 40, and when the moisture value falls below a predetermined value, the grain drying operation by the grain dryer 1 is stopped. The spacing between the multiple electrode rollers 25b2 is adjustable by driving the roller spacing adjustment motor 27 shown in Figure 16.

[0043] Figure 10 is an enlarged perspective view of the vicinity of the upper spiral 7 shown in Figure 1, and Figure 11 is an enlarged perspective view of the vicinity of the diffusion plate 28 located at the top of the drying tank 3 shown in Figure 1.

[0044] The upper spiral 7 is composed of an auger screw and is rotationally driven by the conveying motor 21 shown in Figures 7 and 10, etc., allowing the grain received from the elevator 4 to be conveyed to the rear, specifically to a position above the approximate center of the storage section 3a in a plan view (a position directly above the drying tank 3). Near the end of the conveying section of the upper spiral 7, and above the drying tank 3, a diffusion plate 28 is provided, which is rotationally driven around a rotating shaft 28a. When the grain type setting switch 41 shown in Figure 16 is set to paddy grain, paddy grain is supplied from the upper spiral 7 to the diffusion plate 28, and is dispersed within the storage section 3a by the rotation of the diffusion plate 28.

[0045] Here, at the ceiling of the drying tank 3, approximately in the center of the conveying path by the upper spiral 7, a drop mechanism is provided that causes grains being conveyed by the upper spiral 7 to fall into the storage section 3a before they are diffused by the diffusion plate 28. Specifically, the bottom surface of the approximately central part of the conveying path by the upper spiral 7 is held down from below by a rotating lever 30, which is rotated by the opening / closing motor 29 shown in Figure 11. When the rotating lever 30 is rotated downward, the bottom surface opens (= rotates downward), and the grains being conveyed fall out. When the grain type setting switch 41 is set to paddy rice, the bottom surface of the conveying path is closed, and the paddy grains are conveyed to the diffusion plate 28 and diffused in the storage section 3a. In contrast, when the grain type setting switch 41 is set to corn or soybeans, the bottom surface of the conveying path is open, and the corn or soybean grains being conveyed fall into the storage section 3a without being diffused. In this way, since the corn or soybean grains are dropped by the dropping mechanism without being dispersed by the diffusion plate 28, it is possible to prevent them from coming into contact with the diffusion plate 28 and being damaged. Furthermore, once a certain amount of grain has accumulated, subsequent grains that fall will naturally flow down the surface of the accumulated layer, resulting in even less damage to the grains.

[0046] The driving force of the conveying motor 21 shown in Figure 7, etc., is transmitted to the elevator 4, the lower helix 6, the upper helix 7, and the diffusion plate 28 by belt-type transmission mechanisms 23, 24, etc. Therefore, when the rotational speed of the elevator 4 is adjusted, the rotational speed (=conveying speed) of the lower helix 6, the upper helix 7, and the diffusion plate 28 will also change accordingly. However, for example, an independent motor may be provided to rotate the diffusion plate 28, and the drying operation may be performed with the diffusion plate 28 stopped only when the grain type setting switch 41 is set to corn or soybeans. In addition, the motor that drives the elevator 4, the motor that drives the lower helix 6, the motor that drives the upper helix 7, and the motor that drives the diffusion plate 28 may each be provided independently.

[0047] On the other hand, Figure 12 is a schematic plan view of the grain dryer 1 shown in Figure 1, and Figure 13 is an exploded perspective view of the dust collector 31 shown in Figure 12.

[0048] The upper spiral 7 is covered by a case 7a shown in Figure 12, and a dust remover 31 is mounted on the top surface of this case 7a to suck up and discharge dust, straw, and other debris from the grain being transported by the upper spiral 7.

[0049] The dust collector 31 includes a suction fan for sucking up dust and other particles, and a housing 31b that covers the suction fan. When the suction fan rotates due to the drive of the suction fan drive motor 31a shown in Figure 16, dust and other particles mixed with the grain are sucked up and removed through the suction port 7a1 formed in the case 7a of the upper spiral 7. The suction port 7a1 is provided with a shutter 31c that adjusts its opening, and the amount of air sucked up by the suction fan is changed by sliding this shutter 31c by the shutter opening / closing motor 37 shown in Figure 16. Here, since the suction fan and the exhaust fan 9 draw air from inside the machine body 1, the greater the amount of air sucked up by the suction fan, the lower the amount of hot air discharged by the exhaust fan 9. For this reason, the amount of air discharged by the exhaust fan 9 can be adjusted by changing the position of the shutter 31c. The greater the overlap between the suction port 7a1 and the shutter 31c, and the narrower the suction port 7a1 becomes, the lower the dust collection performance by the suction fan, but the airflow of the exhaust fan 9 increases. Since corn produces relatively little dust, it may be preferable to reduce the suction power of the suction fan and increase the overall airflow. Thus, when the grain type setting switch 41 is set to corn or soybeans, the suction port 7a1 is automatically adjusted to a relatively narrow predetermined opening by the drive of the shutter opening / closing motor 37.

[0050] Furthermore, a net is provided at the lower end of the elevator 4 that selectively allows only fine particles such as dust and soil to pass through and fall. The dust and other particles that pass over the net are stored in the collection box 32 shown in Figures 1 and 6. This configuration is designed to deal with damp dust that is difficult to remove with the aforementioned suction fan. By passing grains over the net with a light impact, damp dust is removed by being stripped off.

[0051] In this way, dust and other debris can be removed using the dust removal machine 31 and the net provided on the elevator 4, allowing grains such as corn to be dried while remaining clean.

[0052] Figure 14 is a partial longitudinal cross-sectional view showing the exhaust air circulation mechanism installed near the exhaust fan 9, and Figure 15 is a graph showing the relationship between the amount of each type of grain loaded and the proportion of hot air recirculated into the drying tank 3.

[0053] A portion of the hot air drawn in by the exhaust fan 9 is returned to the drying tank 3 by an exhaust air circulation mechanism 50 located near the exhaust fan 9.

[0054] The exhaust air circulation mechanism 50 includes a first control valve 51 that directs a portion of the hot air drawn in by the exhaust fan 9 to an exhaust air supply duct 53 that communicates with the drying tank 3, and a second control valve 52 that adjusts the amount of hot air that is returned to the drying tank 3 from the hot air that has been directed into the exhaust air supply duct 53.

[0055] The first control valve 51 is rotated by the first control valve drive motor 51b around the rotation center 51a, and the second control valve 52 is rotated by the second control valve drive motor 52b around the rotation center 52a, thereby adjusting the proportion (amount) of hot air recirculated into the drying tank 3.

[0056] Regardless of the grain type setting on the grain type setting switch 41, the proportion of hot air recirculated into the drying tank 3 is adjusted to decrease as the amount of grain increases. Furthermore, when set to corn, the proportion of hot air recirculated into the drying tank 3 relative to the hot air drawn in by the exhaust fan 9 is controlled to a predetermined ratio that is lower than when set to paddy rice. By adjusting the proportion of recirculated hot air to a relatively low level in this way, the humidity of the hot air flowing through the drying tank 3 can be kept low, and the amount of exhaust air by the exhaust fan 9 can be increased. Note that the proportion of recirculated hot air when set to paddy rice is the same as the proportion when set to buckwheat, so in Figure 15, the lines for buckwheat and paddy rice overlap.

[0057] Figure 16 is a control block diagram of the grain dryer 1 shown in Figure 1. The control device 2 is an information processing device composed of a well-known microcomputer including a CPU and its peripheral circuits.

[0058] The input side of the control device 2 is connected to a volumetric load detection sensor 33 for detecting the amount of grain loaded into the drying tank 3, a moisture meter 25b for measuring the moisture content of the grains, a hot air temperature sensor 34 for detecting the temperature of the hot air generated by the burner 5, an outside air temperature sensor 35 for detecting the outside air temperature, a grain type setting switch 41 for setting the type of grain to be dried, a load switch 42 for loading the grain, a ventilation switch 43 for so-called ventilation operation that drives the exhaust fan 9 and the circulation mechanism, a drying switch 44 for igniting the burner 5 and performing drying operation, and a stop switch 45 for stopping operation. The various switches labeled 41 to 45 are provided in the setting unit 11. The grain type setting switch 41 corresponds to the "setting means" of the present invention.

[0059] The output side of the control device 2 is connected to an inverter 12 that adjusts or switches the power supply to each motor, a proportional control valve 38 that adjusts the amount of fuel supplied to the burner 5, and an operation display panel 40 that displays various information.

[0060] The control device 2 controls the hot air temperature to a preset target temperature (=set temperature) according to the type of grain by controlling the amount of fuel supplied by the proportional control valve 38 based on the values ​​detected by the hot air temperature sensor 34 and the outside air temperature sensor 35.

[0061] The control device 2 is further configured to control the on / off operation and rotational speed of the following motors by outputting control signals to the inverter 12, thereby starting or stopping the power supply to the valve drive motor 8c, the transport motor 21, the helical lifting motor 6a, the claw spacing adjustment motor 26, the opening / closing motor 29, the suction fan drive motor 31a, the shutter opening / closing motor 37, the first control valve drive motor 51b, the second control valve drive motor 52b, the exhaust fan motor 9a, the seal rotation motor 14, and the roller spacing adjustment motor 27, or by increasing or decreasing the frequency of power supply to these motors. For example, changing the rotational speed of the valve drive motor 8c changes the rotational speed of the feed valve 8. Changing the rotational speed of the transport motor 21 changes the rotational speed of the elevator 4, the lower helical 6, the upper helical 7, and the diffusion plate 28, respectively. Changing the rotational speed of the exhaust fan motor 9a changes the rotational speed of the exhaust fan 9, and consequently the airflow and exhaust volume passing through the inner drying net 15 and the outer drying net 16. The control device 2 and inverter 12 are examples of the "valve rotation speed adjustment means," "elevator rotation speed adjustment means," and "airflow adjustment means" of the present invention.

[0062] Figure 17 is a graph showing the relationship between the amount of grain loaded for each type of grain and the set temperature of burner 5. The loading volume detection sensor 33 in this embodiment detects the volume of grain loaded into the drying tank 3 and calculates the loading volume, which is the weight of the grain, by multiplying it by the bulk density value of the grain set by the grain type setting switch 41. The bulk density in the case of corn is greater than the bulk density in the case of rice.

[0063] The load amount detected by the load amount detection sensor 33 is displayed on the operation display panel 40. Based on the load amount thus detected, the output of the burner 5 is controlled to a set temperature (=target temperature) corresponding to the set type of grain and load amount, as shown in Figure 17. The set temperature is adjusted so that the temperature of the hot air generated from the burner 5 increases as the load amount increases. For the same load amount, the set temperature of the burner 5 is in the order of wheat, paddy rice, buckwheat, corn, and soybeans, from highest to lowest. In other words, for the same load amount, the set temperature of the burner 5 when set to corn is lower than when set to paddy rice, and slightly higher than when set to soybeans. This suppresses the occurrence of wrinkles on the surface of corn grains, and since corn is not as prone to wrinkling as soybeans, setting a higher temperature than for soybeans allows for faster drying while suppressing wrinkle formation. In cases where the set temperature is lower than a predetermined value, such as with corn or soybeans, adjusting the output of burner 5 alone is insufficient to lower the temperature to the set temperature. Therefore, burner 5 is configured to operate intermittently, resulting in intermittent combustion. For example, by repeatedly operating burner 5 for 45 seconds and stopping it for 15 seconds, or by repeatedly operating and stopping it every 30 seconds, the temperature of the generated hot air can be lowered to the set temperature. Note that the set temperature of burner 5 when used for corn may be the same as when used for soybeans, and in this case as well, the occurrence of wrinkles on the surface of the corn grains can be suppressed. Figure 18 is a graph showing the relationship between the amount of each type of grain packed in the drying net and the amount of air passing through the inner drying net 15 and outer drying net 16 due to the operation of the exhaust fan 9.

[0064] When the grain type setting switch 41 is set to corn, the rotation speed of the exhaust fan 9, that is, the amount of air passing through the inner drying net 15 and the outer drying net 16, is adjusted to two levels of airflow, which is greater than when it is set to paddy rice, according to the amount of grain being loaded. In this way, by increasing the airflow compared to when it is paddy rice, the drying of the corn can be accelerated, and excessive rise in the temperature of the corn grains can be suppressed, preventing the corn from wrinkling.

[0065] <Technical significance of this embodiment> According to the embodiment shown in Figures 1 to 18, when the grain type is set to corn by operating the grain type setting switch 41, the interference prevention gap G1 between the outer surface of the grain dispensing valve 8 and the lower end of the flow passage 3b1 is adjusted to be larger than that for rice and smaller than that for soybeans, according to the size of the grain. This prevents the grain from getting caught in the interference prevention gap G1 and prevents the corn kernels from being crushed.

[0066] Furthermore, when set to corn, the rotation speed of the dispensing valve 8 is adjusted by the control device 2 and inverter 12 to a speed lower than that for paddy rice and the same as or higher than that for soybeans, according to the size and softness of the grains, thereby further preventing damage to the corn caused by being jammed.

[0067] In addition, when set for corn, the distance between the lower spiral 6 and the bottom surface of the grain collection section 3c (more specifically, the bottom plate 3c2) is adjusted to be wider than that for paddy grains, and the same as or narrower than that for soybeans, depending on the size and softness of the grains, thereby preventing damage to the corn during transport by the lower spiral 6.

[0068] Furthermore, according to this embodiment, when corn or soybeans are selected, the grains are dropped into the storage section 3a by opening the bottom of the transport path without being diffused by the diffusion plate 28, thus preventing damage from contact with the diffusion plate 28.

[0069] Furthermore, according to this embodiment, when set to corn or soybeans, the rotational speed of the elevator 4, which is composed of bucket elevators, is adjusted to be lower than when set to rice, thereby preventing damage to the grains when they are transferred from the elevator 4 to the upper spiral 7.

[0070] In addition, according to this embodiment, the receiving width of the guide member 25a3 that guides the grain to the moisture meter 25b for detecting the moisture content of the grain, that is, the width between the pair of claw portions 25a3a, can be adjusted according to the set type of grain. Therefore, the moisture meter 25b can be used universally for various types of grain, and manufacturing costs can be reduced.

[0071] Furthermore, according to this embodiment, as shown in Figure 17, under the same load amount conditions, the set temperature of the burner 5 for corn is set lower than the set temperature for paddy rice. This suppresses the occurrence of wrinkles on the surface of the corn grains. Moreover, since corn is not as prone to wrinkles as soybeans, setting the burner temperature higher than that for soybeans allows for faster drying while suppressing wrinkle formation. In addition, when set for corn, the airflow passing through the inner drying net 15 and outer drying net 16 forming the flow passage 3b1 is adjusted to be greater than that for paddy rice. Therefore, by increasing the airflow while keeping the burner temperature lower, the drying of the corn can be accelerated even further.

[0072] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the invention as described in the claims, and these modifications are also included within the scope of the present invention.

[0073] For example, in the embodiments shown in Figures 1 to 18, the grain drying operation by the grain dryer 1 is stopped when the moisture content of the grain measured by the moisture meter 25b exceeds a predetermined value. However, corn tends to have a larger moisture content difference between the center and the outer part of the grain compared to soybeans, etc. Therefore, it may be difficult to accurately measure the moisture content of corn grains with an electrical resistance type moisture meter 25b. On the other hand, corn and soybeans have the property of hardening on the surface as drying progresses. Therefore, inside the case section 36 that covers and connects the elevator 4 and the upper spiral 7, when the grain that has been lifted and conveyed by the elevator 4 is passed to the upper spiral 7, the noise gets louder as drying progresses. Given this situation, it is also possible to configure the system to stop the drying operation by stopping the burner 5 when the noise level inside the case section 36 exceeds a preset standard value, as it is recognized that the drying of the grain is complete. Alternatively, instead of a sound level meter, a vibration detection means for detecting the magnitude of vibration may be provided in the case section 36. When the detected vibration value exceeds a preset reference value, it is recognized that the drying of the grain is complete, and the burner 5 may be stopped to cease the drying operation. In both cases, where the moisture content is measured by noise level or vibration level, it is preferable to display the measured moisture content on the operation display panel 40. It is preferable that the reference value be set and changed in advance by the user in the setting section 11 prior to the start of the drying operation. By making the reference value for noise or vibration changeable, it is possible to accommodate differences in corn varieties and grades.

[0074] Furthermore, in the above embodiment, the amount of exhaust air from the drying tank 3 can be adjusted by changing the frequency of the power supplied to the exhaust fan motor 9a. In addition, at least a part of the inner drying net 15 and / or the outer drying net 16 may be configured to be replaceable with a plate that does not allow hot air to pass through. By making it possible to change to a plate in this way, the airflow resistance of the hot air can be changed between the case of a plate and the case of a drying net, and the amount of exhaust air can be adjusted. Needless to say, the amount of exhaust air will be greater when using a drying net. [Explanation of symbols]

[0075] 1. Grain dryer 2 Control device 3 Drying tank 4 Elevators 5 burners 6 lower spiral 7 Upper spiral 8. Dispensing valve 9 Exhaust fan 10 Supply hoppers 11. Settings section 12 Inverters 13. Seal part 14. Seal Rotary Motor 15 Drying net 16 Drying net 17 volts 18 Rotating Plates 19. Pivot 20 stickers 21. Conveyor motor 23. Belt-type transmission mechanism 24. Belt-type transmission mechanism 25 Moisture Measurement Section 26. Claw spacing adjustment motor 27. Roller spacing adjustment motor 28 Diffusion plate 29. Switching motor 30 Rotating levers 31 Dust extractor 32 Collection Boxes 33. Stress level detection sensor 34. Hot air temperature sensor 35. Outdoor temperature sensor 36 Case section 37. Shutter opening / closing motor 38 Proportional control valve 40. Operation display panel 41. Grain type setting switch 42. Fixed switch 43 Ventilation switch 44 Drying switch 45 Stop switch 50 Exhaust air circulation mechanism 51. First control valve 52 Second Control Valve 53 Exhaust supply duct

Claims

1. A grain dryer for drying various grains, including rice, soybeans, and corn, A storage section for storing grain, It has a flow passage for allowing grain to flow down from the storage section, and a drying section for drying the flowing grain by applying hot air, A dispensing valve that receives and dispenses the grains that have flowed down the aforementioned flow passage, A grain collection unit for collecting grains dispensed by the aforementioned dispensing valve, The aforementioned grain collection section includes an elevator that lifts and circulates the collected grain, A seal portion is disposed to cover the lower part of the interference prevention gap formed between the outer circumferential surface of the dispensing valve and the lower end of the flow passage, and is configured to adjust the width dimension of the interference prevention gap by rotational movement, A gap adjustment means for freely adjusting the width dimension of the interference prevention gap by rotating the seal portion, A valve rotation speed adjustment means for adjusting the rotation speed of the aforementioned dispensing valve, It includes a setting means that accepts a predetermined operation from the user and sets the type of grain to be dried, When the type of grain to be dried is set to corn by the setting means, the gap adjustment means adjusts the width dimension of the interference prevention gap to a dimension that is larger than when it is set to rice, and smaller than when it is set to soybeans, A grain dryer characterized in that a valve rotation speed adjustment means is configured to adjust the rotation speed of the dispensing valve to a speed lower than that when set for paddy rice, and the same as or higher than that when set for soybeans.

2. A lower spiral is provided in the grain collection section and transports the grain dispensed by the dispensing valve to the elevator. The system includes a lower spiral position changing means that can adjust the distance between the lower spiral and the bottom surface of the grain collection section by changing the vertical position of the lower spiral, The grain dryer according to claim 1, characterized in that when the setting means is set to corn, the lower spiral position changing means is configured to adjust the spacing to be wider than when it is set to paddy rice, and the same as or narrower than when it is set to soybeans.

3. An upper spiral receives the grains that have been lifted and transported by the elevator and transports them to a position above the approximate center of the storage section in a plan view, A diffusion plate is positioned near the end of the upper spiral conveying section and diffuses the grains conveyed by the upper spiral within the storage section. The upper spiral provides a dropping mechanism that causes the grains being transported to fall before they are diffused by the diffusion plate, The system includes elevator rotation speed adjustment means for adjusting the rotation speed of the elevator, which is composed of a bucket elevator, The grain dryer according to claim 1 or 2, characterized in that when the setting means is set to rice, the grain is diffused into the storage section by the diffusion plate, whereas when the setting means is set to corn or soybeans, the grain is dropped by the dropping mechanism, and the elevator rotation speed adjustment means is configured to adjust the rotation speed of the elevator to a lower speed than when it is set to rice.

4. A moisture meter that grinds grains and measures the moisture content of the grains, A guide member that receives the grains that fall from the elevator one by one and guides them to the moisture meter, The system includes a receiving dimension adjustment means for adjusting the particle size of grains that can be accepted by the guide member by changing the width of the guide member, The grain dryer according to claim 1 or 2, characterized in that when the setting means is set to corn, the receiving dimension adjustment means is configured to adjust the width of the guide member to be greater than when it is set to paddy rice, and the same as or smaller than when it is set to soybeans.

5. Equipped with a burner that generates hot air to direct onto the grain, When the setting means is used to select rice, soybeans, or corn, the burner is configured to have a higher set temperature as the amount of grain loaded increases. The grain dryer according to claim 1 or 2, characterized in that when set to corn using the setting means, the burner setting temperature for the same loading amount is lower than when set to paddy rice, and the same as or higher than when set to soybeans.

6. The flow passage is formed by a drying net through which the hot air generated by the burner passes, and the grain dryer is equipped with an airflow adjustment means for adjusting the amount of air passing through the drying net. The grain dryer according to claim 5, characterized in that when the setting means is set to corn, the airflow adjustment means is configured to adjust the airflow to be greater than when it is set to paddy rice.

7. A sound level meter is positioned in the case that connects the elevator and the upper spiral. The grain dryer according to claim 3, wherein the grain drying operation is stopped if the noise level measured by the sound level meter exceeds a preset standard value, and the standard value is changeable.

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