JP4374733B2 - Grain dryer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a burner control device, and can be used in a dryer or the like for drying grain.
[0002]
[Prior art]
A blower is provided in a burner that supplies hot air to the hot air chamber so that the burner can be cooled, and after the drying operation is completed, the blower is blown to the burner for a predetermined time, so that a so-called post-purge operation is conventionally performed. well known.
[0003]
Also, a device that uses one temperature sensor to compare the deviation value between the temperature during operation and the temperature after burner combustion stop with a preset deviation value, and stops the post-purge operation at the time when they match is known. (Japanese Patent Laid-Open No. 7-286728).
[0004]
[Problems to be solved by the invention]
However, in the above-mentioned known example, even if the burner temperature decreases after the burner combustion is stopped, if the burner is not blown for a predetermined time by the blower, the entire apparatus does not stop, so that the next work cannot be performed, which is in terms of work efficiency. There are problems such as increased power consumption and prolonged noise caused by driving.
[0005]
Also, the temperature during operation and the temperature deviation after burner combustion stop are compared with a preset deviation by a single temperature sensor, and the post-purge operation is stopped when the values match. In the case of a grain dryer or the like that controls the hot air temperature in order to keep the grain drying rate constant, it is necessary to change the set value of the deviation depending on the conditions, resulting in a complicated control.
[0006]
An object of the present invention is to eliminate the waste of post-purge operation, increase work efficiency by simple control means, reduce power consumption, and reduce noise.
[0007]
[Means for Solving the Problems]
In order to achieve this object, the invention described in claim 1 supplies hot air generated by the burner (17) provided in the burner case (18) toward the hot air chamber (5) , and by the blower (24). In a grain dryer configured to perform a post-purge operation in which the burner after cooling is cooled by ventilation, an outside air temperature sensor (26) for detecting the outside air temperature and a hot air temperature sensor (14 ) for detecting the temperature of the hot air chamber. ), And after the combustion of the burner (17) is stopped, the difference between the temperature detected by the outside air temperature sensor (26) and the temperature detected by the hot air temperature sensor (26) is less than a predetermined value , and the predetermined value a control means for stopping the post-purge operation is provided when the following conditions continues for a predetermined time, the upper corner portion inside of said burner casing (18) is a partition plate (28) is provided, specifications and the burner casing (18) With arranging the outdoor air temperature sensor (26) in a space constituted out with a plate (28), the burner casing (18) corner portion, characterized in that a slit (29) for introducing outside air.
[ 0008 ]
[0009]
Operation and effect of the invention
According to the present invention, after burning of the burner is stopped, the difference between the temperature detected by the outside air temperature sensor and the temperature detected by the hot air temperature sensor is compared. The post-purge operation by the blower is stopped, and the suction fan is also stopped.
[0010]
In this way, the reference of the temperature difference is set to the temperature detected by the outside temperature sensor, so that control becomes easy, burner cooling can be reliably determined, post-purge operation is not wasted, and work efficiency is improved by simple control means. , Power consumption can be reduced, and noise can be reduced.
[0011]
Further, when the difference between the temperature detected by the outside air temperature sensor and the temperature detected by the hot air temperature sensor becomes equal to or smaller than a predetermined value and the state equal to or smaller than the predetermined value continues for a predetermined time, the post-purge operation by the blower is stopped. . By controlling in this way, when the condition is not satisfied within a predetermined time, it can be estimated that the remaining fuel in the burner is reburned, and the cooling of the burner can be further ensured.
In addition, a slit 29 through which the outside air can be introduced is provided at the upper corner of the burner case 18 so that the outside air passes through the outside air temperature sensor 26 through the slit 29 without being affected by the heat of the burner 17 by the partition plate 28. Can
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. A grain dryer 1 according to the present invention is a circulation type drying device that dries grains, and a storage chamber 2, a drying chamber 3, an exhaust air chamber 4, a hot air chamber 5, and the like are provided inside the machine frame 7. And a tension hopper 6 for tensioning grains on the side wall of the hot air chamber 5 is provided.
[0013]
An upper transfer device 8 having a discharge funnel (not shown) is provided in the ceiling portion of the storage chamber 2 above the machine frame 7, and the grains are transferred to the diffusion device 39 in the center of the ceiling portion by an internal transfer spiral 38. . The drying chamber 3 is provided on the lower side of the storage chamber 2 as a pair on the left and right sides, and is provided between the exhaust air chamber 4 and the hot air chamber 5 in order to allow hot air to flow while drying the grains gradually. . Under these drying chambers 3, a rotary valve 9 that rotates forward and backward alternately and feeds and flows down grains by a fixed amount is rotatably supported along the longitudinal direction of the machine body. The rotary valve 9 has a groove-shaped receiving portion formed in the axial direction thereof, and is configured such that the grains fall when the rotary valve 9 rotates and the receiving portion is positioned below.
[0014]
A lower conveying spiral 10 is arranged at the lower part of the hot air chamber 5, and the grain fed by the rotary valve 9 is transferred toward the elevator 11 arranged on the front side of the machine body, and the elevator is connected via the return rod 12 on the terminal side. 11 to be transported. The elevator 11 is provided with a moisture meter 13 that samples the grains in the elevator 11 and measures moisture. A hot air temperature sensor 14 is provided in the hot air chamber 5.
[0015]
The suction fan 15 for sucking hot air is configured to be driven by the machine motor 16, and the machine motor 16 simultaneously drives the lower transport spiral 10, the elevator 11, and the transport spiral 38 of the upper transport device 8. The rotary valve 9 is driven by a rotary valve motor (not shown).
[0016]
Next, the burner 17 will be described with reference to FIGS. The burner 17 is provided in a position in the burner case 18 outside the opening 34 provided in the hot air chamber 5, and the burner 17 is fixed to a mounting base 19 provided in the burner case 18. The mounting base 19 is provided with a fuel valve 21 and a fuel pump 22 which are controlled to open and close in response to a signal from a controller 20, which will be described later, for example, a pulse signal with variable on-time, and supply a predetermined amount of fuel to the burner 17. Of these, the fuel pump 22 is connected to a fuel tank 23 provided below the burner case 18. The burner 17 is provided with a blower 24 and a blower motor 25 for adjusting the air volume of the blower 24.
[0017]
26 is an outside air temperature sensor for detecting the outside air temperature, and is provided inside the upper corner of the burner case 18 so as to be positioned above the combustion part 27 of the burner 17. That is, a partition plate 28 is provided inside the upper corner of the burner case 18, and the outside air temperature sensor 26 is arranged in a space formed by the burner case 18 and the partition plate 28. A slit 29 through which the outside air can be introduced is provided at the upper corner of the burner case 18, and the outside air passes through the outside air temperature sensor 26 through the slit 29 without being affected by the heat of the burner 17 by the partition plate 28. It is configured as follows.
[0018]
Furthermore, various drying operation programs are built in the upper surface of the burner case 18 to drive the machine system (referred to as the machine motor system) such as the lower transport spiral 10, the elevator 11, the upper transport device 8, the rotary valve 9, and the suction fan 15. A controller 20 is provided for controlling the operation of the burner 17 and the blower 24 (referred to as a burner system).
[0019]
The controller 20 includes a tension switch 30 for driving the motor system excluding the rotary valve 9, a drying switch 31 for operating the motor system and the burner system, and a flow path for discharging the grain. Is provided with a discharge switch 32 for driving the gas and a stop switch 33 for stopping the drying operation.
[0020]
Next, the operation of the above embodiment will be described. In such a configuration, when the grain dryer 1 pushes the drying switch 31 after the grain is stuck in the grain dryer 1 by the tension switch 30, the burner 17 sends hot air to the hot air chamber 5. Grains are gradually fed in the drying chamber 3 while being circulated by circulating a certain amount by the rotary valve 9 while being ventilated and flowing down to the lower conveying spiral 10 and then transferred to the elevator 11 and returned to the storage chamber 2 again. When the predetermined moisture value is reached, the fuel supply to the burner 17 is stopped, and the motors of the main system except the suction fan 15 are stopped.
[0021]
After the combustion of the burner 17 is stopped, the outside air temperature is measured by the outside air temperature sensor 26 and is set to A (° C.). Next, the temperature inside the hot air chamber 5 is measured by the hot air temperature sensor 14 and is set to B (° C.). If it is in the post-purge operation, it is determined whether or not | B−A | ≦ α (° C.). If the condition is satisfied, the post-purge operation is terminated and the suction fan 15 is also stopped and dried. The work is finished (FIG. 5).
[0022]
Since the temperature difference is set to the temperature detected by the outside air temperature sensor 26 in this way, the control becomes easy, the cooling of the burner 17 can be reliably determined, the waste of the post purge operation is eliminated, the power consumption is reduced, Noise can be reduced. FIG. 6 shows an embodiment in which, after satisfying the above condition, if this state continues for a predetermined time β (sec) or longer, the post-purge operation is terminated, the suction fan 15 is also stopped, and the drying operation is terminated. When the above condition is not satisfied within β (sec), the reburning of the remaining fuel in the burner can be estimated, and the cooling of the burner 17 can be further ensured.
[0023]
Incidentally, as shown in FIG. 4, in the grain dryer 1 in which the grain is stretched from the stretching hopper 6, the grain inlet 40 is positioned in the very vicinity of the burner 17, and the burner 17 burns. Grains are scattered on the portion 27 and dust is likely to adhere to the combustion portion 27. Further, if the opening 34 through which the hot air from the burner 17 flows is simply provided on the front surface of the machine frame 7, a vortex is generated downstream of the opening 34 when the hot air flows in, resulting in large pressure loss and ventilation resistance. As a result, the machine casing 7 may become hot.
[0024]
Therefore, in order to solve the above problem, FIG. 7 shows a heat shield that has a gap from the machine frame 7 at the lower side of the opening 34 or the opening 34 close to the drying chamber 3 and extends a predetermined distance into the machine. 8 shows an embodiment in which a plate 35 or a heat shield plate 36 is provided. FIG. 8 shows another embodiment in which an integrally formed heat shield plate 37 is provided on the lower side of the opening 34 and the opening 34 near the drying chamber 3. Indicates.
[0025]
Thus, while the periphery of the opening 34 is exposed to a high temperature by the burner 17, the heat shield plates 35, 36, 37 do not cause the drying chamber 3 in the vicinity of the machine frame 7 and the burner 17 to become a high temperature and reduce the ventilation resistance. In addition, there is an effect of preventing the scattering of the grains from the tension hopper 6 at the time of tension.
[0026]
In addition, when a grain is stretched from the stretching hopper 6, an embodiment based on a time chart showing the operation of the motor system and the blower motor 25 for the purpose of preventing the grain scattering to the burner 17 and the dust adhesion is shown. 9 shows. That is, when the tension switch 30 is pressed, the motor system other than the rotary valve 9 is driven. At the same time, the blower 24 is driven, and the outside air sucked by the blower 24 is blown from the combustion unit 27 of the burner 17 without heating. As a result, even if extremely dusty grains are stuck and scattered in the vicinity of the burner 17, the next drying operation can be easily performed without the dust being attached to the combustion unit 27 by the air blowing. .
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view in the width direction of a grain dryer.
FIG. 2 is a longitudinal cross-sectional view of the main part of a grain dryer.
FIG. 3 is a front view of a burner.
FIG. 4 is a side sectional view of a burner.
FIG. 5 is a flowchart showing a burner control flow according to the present invention.
FIG. 6 is a flowchart showing a burner control flow according to the present invention.
FIG. 7 shows heat shield plates 35 and 36 in the opening on the front side of the machine frame.
FIG. 8 shows an embodiment of a heat shield plate 37 at the opening on the front side of the machine frame.
FIG. 9 is a time chart.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Grain dryer 2 ... Storage chamber 3 ... Drying chamber 4 ... Exhaust chamber 5 ... Hot air chamber 6 ... Stretch hopper 7 ... Machine frame 8 ... Upper conveyance apparatus 9 ... Rotary valve 10 ... Lower conveyance spiral 11 ... Elevator 12 ... Return rod 13 ... Moisture meter 14 ... Hot air temperature sensor 15 ... Suction fan 16 ... This machine motor 17 ... Burner 18 ... Burner case 19 ... Mounting base 20 ... Controller 21 ... Fuel valve 22 ... Fuel pump 23 ... Fuel tank 24 ... Blower 25 ... Blower motor 26 ... Outside air temperature sensor 27 ... Combustion unit 28 ... Partition plate 29 ... Slit 30 ... Tension switch 31 ... Drying switch 32 ... Discharge switch 33 ... Stop switch 34 ... Opening 35 ... Heat shield plate 36 ... Heat shield Plate 37 ... Heat shield plate 38 ... Conveyance spiral 39 ... Diffusion device 40 ... Grain inlet

Claims (1)

The configuration is such that the hot air generated by the burner (17) provided in the burner case (18) is supplied to the hot air chamber (5), and the post-purge operation is performed to cool the burner after the combustion is stopped by the blower (24). In the grain dryer , the outside air temperature sensor (26) for detecting the outside air temperature and the hot air temperature sensor (14) for detecting the temperature of the hot air chamber are provided, and after the combustion of the burner (17) is stopped, the outside air the difference between the detected temperature by the temperature sensor (26) temperature and the hot air temperature sensor detected in (26) becomes below a predetermined value, and a predetermined value or less in the state to stop post-purge operation is continued a predetermined time control unit Provided,
A partition plate (28) is provided inside the upper corner of the burner case (18), an outside air temperature sensor (26) is disposed in a space formed by the burner case (18) and the partition plate (28), and A grain dryer characterized in that a slit (29) for introducing outside air is formed in the upper corner of the burner case (18) .

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