Circulating grain dryer

Abstract

To provide a circulation type grain dryer capable of uniformizing a hot air temperature, preventing uneven temperatures in hot air, and improving drying efficiency.SOLUTION: The circulation type dryer at least comprises a drying unit 12 capable of drying grain, an air supply device 11 capable of supplying the drying unit 12 with hot air, and an exhaust device 13 capable of discharging air present in the drying unit 12 to outside of the dryer. The air supply device 11 comprises a centrifugal blower 112 connected to the drying unit 12, a burner 113 functioning as a heat source, and a cover body 111 covering the centrifugal blower 112 disposed in a space of a predetermined size. Hot air of the burner 113 and outdoor air are supplied into the space covered with the cover body 111.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention particularly relates to a pressure-feed and suction type circulating grain dryer.

Background Art

[0002] Former circulating grain dryers provided a suction fan to pressure-feed and supply hot air by an axial flow blower and to exhaust the dried air outside the machine. Thereafter, grain dryers provided only with a suction fan without an axial flow blower, such as those disclosed in Patent Document 1 for example, have become mainstream.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the above-mentioned former circulating grain dryers have the problem that since the pressure-feed blower is axial flow type, it is difficult for the heat of the burner and the outside air to mix, and it is difficult for the temperature of the hot air supplied into the drying section to become uniform. In addition, when the pressure-feed blower is axial flow type, there is also a problem that the bearing of the pressure-feed blower becomes high in temperature and its durability is poor. Further, even in the suction type grain dryer as disclosed in Patent Document 1, it has not been possible to supply hot air of completely uniform temperature into the dryer.

[0005] Therefore, in view of such problems, an object of the present invention is to provide a circulating grain dryer capable of equalizing the hot air temperature, suppressing temperature unevenness of the hot air, and improving the drying efficiency in a circulating grain dryer.

Means for Solving the Problems

[0006] To solve the above-mentioned problems, the present invention provides a circulating grain dryer comprising at least a drying section capable of drying grain, a blower capable of blowing hot air to the drying section, and an exhaust system capable of discharging the internal air of the drying section to the outside of the machine, wherein the blower comprises a centrifugal blower connected to the drying section, a burner that serves as a heat source, and a cover body that places and covers the centrifugal blower in a space of a predetermined size, and hot air from the burner and outside air are supplied to the space covered by the cover body. [Effects of the Invention]

[0007] According to the present invention, the centrifugal blower of the blower device mixes the hot air from the burner with the outside air by centrifugal action within the space covered by the cover body, generating hot air at a uniform temperature which can then be supplied to the drying section. As a result, compared to conventional axial-flow grain dryers that lack centrifugal stirring action, or grain dryers equipped only with suction fans, it is possible to reduce uneven drying of grain and improve the drying efficiency of the circulating grain dryer. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view of a circulating grain dryer in one embodiment of the present invention. [Figure 2] This is a perspective view of a blower in one embodiment of the present invention. [Figure 3] This is a cross-sectional view of a blower in one embodiment of the present invention. [Figure 4] This is a perspective view of a blower device in another embodiment of the present invention. [Modes for carrying out the invention]

[0009] An embodiment of the circulating grain dryer of the present invention will be described below with reference to the drawings. In each figure, the black arrows indicate the flow of hot air, and the white arrows indicate the flow of outside air.

[0010] Figure 1 shows a cross-sectional view of the circulating grain dryer 1 in this embodiment, and Figure 2 shows a perspective view of the blower 11. The circulating grain dryer 1 in this embodiment includes at least a drying section 12 capable of drying grain, a blower 11 capable of blowing hot air to the drying section 12, and an exhaust device 13 capable of discharging the air inside the drying section 12 to the outside of the machine. The blower 11 includes a centrifugal blower 112 connected to the drying section 12, a burner 113 that serves as a heat source, and a cover body 111 that places and covers the centrifugal blower 112 in a space of a predetermined size. Hot air from the burner 113 and outside air are supplied to the space covered by the cover body 111.

[0011] To explain in more detail, as shown in Figures 2 and 3, the centrifugal blower 112 of the blower device 11 has a rotating blade 1124 rotatably housed in a scroll casing 1122, and an intake port 1121 is formed on its side to draw in hot air from the space covered by the cover body 111.

[0012] Furthermore, the centrifugal blower 112 of the blower device 11 is connected to the drying section 12, and a portion of the scroll casing 1122 and the air outlet 1123 beyond it are positioned inside the drying section 12. In this way, by incorporating a portion of the scroll casing 1122 into the drying section 12, the blower device 11 and the circulating grain dryer 1 are made more compact while still accommodating a centrifugal blower 112 of a certain size.

[0013] Furthermore, the joint between the centrifugal blower 112 of the blower device 11 and the drying section 12 is sealed and connected to prevent outside air (cold air) from entering the drying section (drying air tunnel) 12, as shown in the figures. Also, as shown in Figures 1 and 2, the centrifugal blower 112 is covered by a cover body 111, leaving a predetermined space of size laterally around the intake port 1121.

[0014] Furthermore, as shown in Figures 2 and 3, a burner 113, which serves as a heat source for the hot air, a combustion furnace 114, and a wind tunnel pipe 115 that guides the hot air generated from the combustion furnace 114 upwards are arranged laterally and below the centrifugal blower 112 of the blower device 11.

[0015] In addition, an outside air intake port 116 capable of taking in outside air is located below and to the side of the wind tunnel tube 115 as shown in the figure. The hot air from the burner 113 and the outside air drawn in through the outside air intake port 116 are supplied into the interior of the cover body 111 from a lateral and downward position of the centrifugal blower 112.

[0016] With the configuration of this embodiment as described above, the centrifugal blower 112 of the blower 11 draws in hot air from the burner 113 and outside air, and stirs it with the centrifugal action of the rotating blades 1124 to generate hot air at a uniform temperature, which can then be supplied to the drying section 12. As a result, compared to conventional axial fans that do not have a centrifugal stirring action, it is possible to suppress uneven drying of grain and improve the drying efficiency of the circulating grain dryer 1.

[0017] In addition, the centrifugal blower 112 is structurally less expensive to manufacture than an axial fan, thus reducing the overall manufacturing cost of the circulating grain dryer 1. Furthermore, since the bearings do not become excessively hot due to the hot air, as can happen with axial fans, durability can be improved.

[0018] Next, as shown in Figure 1, the exhaust device 13 of this embodiment is equipped with a centrifugal suction blower 131 having the same airflow capacity as the centrifugal blower 112 of the blower device 11, and it sucks in the internal air from the drying section 12 and discharges it outside the machine through the discharge duct 132.

[0019] In addition, the centrifugal blower 112 of the blower device 11 and the centrifugal suction blower 131 of the exhaust device 13 are controlled by one inverter, and the rotational speeds of the respective centrifugal blowers 112 and centrifugal suction blowers 131 are configured to be controlled simultaneously. That is, it is configured such that the air volume can be controlled by simultaneously controlling the rotational speeds of both the centrifugal blower 112 and the centrifugal suction blower 131.

[0020] As a result, the position of zero negative pressure in the drying section 12 becomes the center position of the drying section 12, and the balance between the pressure feeding by the blower device 11 and the suction by the exhaust device 13 is achieved, so that ventilation can be made uniform throughout the drying section 12. Furthermore, with the addition of the effect of uniformizing the hot air temperature described above, uneven drying of the grains can be suppressed, and the drying quality of the grains and the drying efficiency in the circulation type grain dryer 1 can be improved.

[0021] (Other embodiments) As described above, one embodiment of the circulation type grain dryer 1 in the present invention has been described, but it is not necessarily limited to the above-described examples.

[0022] In the above-described embodiment, the centrifugal blower 112 is placed vertically, but it is also possible to place it horizontally.

[0023] Also, the placement location of the burner 113 is not limited to the above-described embodiment. For example, as shown in FIG. 4, it may be placed in the empty space below the drying section 12. In addition, although the separation distance between the centrifugal blower 112 and the burner 113 becomes short, the burner 113 may be installed at a lateral position of the centrifugal blower 112.

[0024] Furthermore, in the above-described embodiment, the airflow rate can be controlled by simultaneously controlling the rotational speed of the centrifugal blower 112 of the blower 11 and the rotational speed of the centrifugal suction blower 131 of the exhaust device 13 using a single inverter. However, the system is not limited to this configuration. For example, the centrifugal blower 112 of the blower 11 and the centrifugal suction blower 131 of the exhaust device 13 may have the same airflow capacity, while the rotational speed of the centrifugal suction blower 131 of the exhaust device 13 may be set lower than the rotational speed of the centrifugal blower 112 of the blower 11.

[0025] More specifically, inverters are provided for controlling the centrifugal blower 112 of the blower unit 11 and the centrifugal suction blower 131 of the exhaust unit 13. This allows the rotation speed of only the centrifugal suction blower 131 of the exhaust unit 13 to be reduced, while the centrifugal blower 112 of the blower unit 11 is operated at its normal rotation speed. This reduces the noise from the centrifugal suction blower 131 of the exhaust unit 13, which is closer to the outdoors, and since the rotation speed of the centrifugal blower 112 of the blower unit 11 is not reduced, the combustion rate of the burner 113 does not need to be significantly reduced, and the drying time is not significantly delayed.

[0026] In addition, by reducing only the rotation speed of the centrifugal suction blower 131 of the exhaust device 13, it is possible to suppress the situation in which branches, stalks, and other debris are discharged outside the machine along with the exhaust from the centrifugal suction blower 131. Branches and other debris that fall before being discharged outside the machine are collected in a receiving box installed at the bottom of the exhaust drum (not shown) and can be collected after drying is complete.

[0027] Up to this point, the configuration of embodiments of the present invention has been described, but the present invention is not limited to the embodiments and other embodiments described above with reference to the drawings. It will be apparent to those skilled in the art that various modifications and substitutions are possible, or that circulating grain dryers including configurations essentially equivalent to those of the embodiments described above can be realized without departing from the scope and spirit of the appended claims. [Explanation of Symbols]

[0028] 1 Circulating grain dryer 11. Blower 12 Drying section 13 Ventilation device 111 Cover body 112 Centrifugal blower 113 Burner 114 Combustion furnace 115 Wind tunnel tube 116 Outside air intake 131 Centrifugal suction blower 132 Exhaust duct 1121 Inlet 1122 Scroll Casing 1123 Air outlet 1124 Rotary blade

Claims

1. It comprises at least a drying section capable of drying grains, a blower capable of blowing hot air into the drying section, and an exhaust system capable of discharging the internal air of the drying section to the outside of the machine. The blower comprises a centrifugal blower connected to the drying section, a burner that serves as a heat source, and a cover body that places and covers the centrifugal blower within a space of a predetermined size. The cover body forms a predetermined space in front of the intake port of the centrifugal blower and covers the space, and the portion facing the intake port is covered by the cover body. The burner is positioned below or to the side of the centrifugal blower. Hot air from the burner and outside air are supplied to the space covered by the cover body. A circulating grain dryer characterized by the following features.

2. The hot air from the burner and the outside air are supplied into the cover body from a lateral and downward position of the centrifugal blower. The circulating grain dryer according to claim 1.

3. The exhaust system includes a centrifugal suction blower having the same airflow capacity as the centrifugal blower of the blower, and the rotation speeds of each centrifugal blower and centrifugal suction blower are simultaneously controlled by a single inverter. A circulating grain dryer according to claim 1 or 2.

4. The exhaust device includes a centrifugal suction fan having the same airflow capacity as the centrifugal fan of the blower, and the rotational speed of the centrifugal suction fan of the exhaust device can be controlled to be lower than the rotational speed of the centrifugal fan of the blower. A circulating grain dryer according to claim 1 or 2.

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