JPH0723766B2 - Hot air generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hot air generator, which can be used in a grain dryer or the like.

[Problems to be Solved by Prior Art and Invention]

For example, in the above grain dryer, a burner is provided on one side of the hot air chamber that is long in the front and rear, and a suction wind from a suction fan on the other side is created across the grain flow passage to mix the burner flame with the outside air. The burner is accommodated in a box-shaped wind tunnel through which suction air can pass, and a duct for promoting mixing of the burner flame with the introduced outside air is connected to the front side of the burner. On the other hand, as for burners, vaporization burner forms, which are advantageous for instantaneous ignition and extinguishing, have become popular in recent years.

However, in this vaporization burner, in the form in which the vaporization cylinder that receives the burner flame and promotes the vaporization of the mixed fuel of the liquid fuel and the combustion air is arranged in the central portion of the combustion cylinder, the introduced outside air that passes through the outer peripheral portion of the combustion cylinder. It is easily affected by the wind. That is, when the burner is installed in the wind tunnel and the distance between the combustion plate and the duct connecting portion is set to be relatively large (Fig. 9a), the flow velocity of the introduced outside air flowing around the burner case becomes faster. Immediately after passing through the combustion plate, it suddenly opens and swirl is apt to occur on the front surface of the combustion plate, and the burner flame abnormally heats the vaporizing cylinder. Further, when the combustion plate is installed so as to partially project into the duct (FIG. 7B), the flow velocity of the introduced outside air wind is once increased when it moves from the wind tunnel to the duct side where the opening area is narrow, and then the outer periphery of the combustion plate is increased. After that, the front surface immediately before the combustion plate suddenly becomes open, and a vortex flow is generated on the front surface just before the combustion plate in the same manner as described above. Therefore, the flame influence on the vaporizing cylinder cannot be ignored.

[Means for solving problems]

In order to solve the above-mentioned drawbacks, the present invention locates a vaporizing cylinder 23 for vaporizing the liquid fuel that is internally flowing close to the flame in a substantially central portion and for burning the vaporized fuel ejected from the combustion disc 27. A duct 39 is provided on the front side of the burner 6 in which the 26 are arranged, for increasing the flow velocity of the air flow from the rear side or the side part of the burner 6 and joining the air flow and the burner 6 flame. A hot air generating device is provided in which the front edge of the cylinder (26) is provided close to the entrance of the duct (39).

[Operation and effect of the invention]

The outside air introduced from the back or the side of the burner has a slightly increased flow velocity on the outer periphery of the burner, and is collected and introduced at the duct entrance. Therefore, even if the introduced outside air wind blows through the side portion and is collected later when moving from the rear side to the front side of the combustion cylinder, the inertia shifts to a state in which the generation of the vortex is delayed.

The burner flame ejected toward the duct side merges with the introduced outside air to generate hot air.However, as described above, there is no sudden change in wind speed before and after the combustion tube, and the occurrence of vortex flow is delayed. That is, there is little turbulence such as eddy current due to the sudden change of the outside air flow velocity, the flame circulation in the front surface of the combustion cylinder is close to the laminar flow state, the vaporization cylinder heating by the flame is good, and the stable fuel vaporization is promoted. However, burner combustion can be secured. This is particularly advantageous when the combustion amount is small and the amount of combustion air is small.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

1 is a machine frame of a grain dryer, in which a storage tank 2, a drying chamber 3 and a grain collecting chamber 4 are vertically installed from the upper part, and one of the grain collecting chamber 4 is provided outside the machine frame 1. Storage tank 2 for grains collected on the side
The frying machine 5 for lifting and reducing is erected. In addition, the drying chamber 3
Hot air chamber 8 and suction fan 9 communicating with the wind tunnel 7 surrounding the burner 6.
The grain flow-down passages 12, 12 partitioned by a breathable material are formed between the exhaust air chamber 11 communicating with the fan shell 10 having the above, and the feeding valves 13, 13 provided at the bottom of each flow-down passage 12, 12 are fixed. This is a configuration in which hot air is blown onto the grains flowing down by a predetermined amount by rotation to dry them.

The fried machine 5 has a structure in which a bucket belt is wound inside, and is configured to be able to transfer the dried grain transferred to one side by a lower transfer spiral 14 laid laterally to the lower part of the grain collection chamber 4 to the scooping upper part. . Grains scooped by the fried machine 5 and thrown at the upper part are guided to the starting end side of a transfer gutter 16 provided with an upper transfer spiral 15. The grain horizontally transferred by the transfer spiral 15 is guided to the rotary diffusion plate 17 arranged in the upper center of the storage tank 2 and is diffused and dropped into the storage tank 2.

The burner 6 is provided in a horizontal posture on a substrate 18 fixed to a machine frame via a support leg portion 19, a combustion air introducing cylinder 20 is connected to the rear portion, and a suction fan 21 and the fan are provided inside.
A case body 25 for accommodating a motor 22 for 21 and a vaporization cylinder 23 driving motor 24 and the like, a dish-shaped combustion cylinder 26 connected to the front surface of the case body 25, the vaporization cylinder 23 located in the center of the combustion cylinder 26, It is composed of a combustion plate 27 and the like which is fitted into the combustion cylinder 26 and ejects vaporized fuel from a large number of ejection ports. Liquid fuel such as kerosene is used as fuel pump.
The vaporization cylinder 23 is supplied to the peripheral surface of the diffuser 32 provided on the tip side of the rotating shaft 31 through which the vaporization cylinder 23 is rotated through the 28, the fuel valve 29, the nozzle 30, and the like. Reference numeral 33 is a blower tube, and 34 is an ignition heater provided on a bulged portion 26a of a part of the outer circumference of the combustion tube 26.

At the bottom of the substrate 18, a container-like filter case 35 formed in a shallow bottom is provided so as to be slidable back and forth.
A filter is installed in an inclined posture in the board 35, and the board 18
An intake port 36 is provided at a position below the combustion tube 26, and an exhaust port 38 is provided at a position corresponding to a guide tube 37 provided on the substrate 18. The guide cylinder 37 connects one end of the combustion air introducing cylinder 20.

On the other hand, a duct 39 having a rectangular inlet cross section is connected to the front side of the substrate 18. That is, the rectangular tubular body formed by the left and right side wall portions and the upper and lower opposing wall portions that have a narrower facing distance toward the front is a substrate.
The front half of the 18 and the bent edges 18b and 18c on the left and right sides of the descending sloped portion 18a continuous with the front half are integrated by welding means.

The main body of the burner 6 is fixedly supported on the base plate 18 to the duct 39 by the support leg portion 19 and the upper grip-like connecting member 41. At this time, the front edge B of the burner 6 combustion tube 26 is arranged so as to coincide with or approach the virtual inlet of the duct 39 (for example, the distance C is 10 to 30 mm).

The wind tunnel 7 that should surround the burner 6 has a mesh frame 42 that is biased to one side and can ventilate on its rear surface, and is attached to and detached from the machine frame 1 by upper and lower fasteners 43 and 44. It is possible. The burner 6 substrate 18 is provided with a vertical bent edge on the rear end side of the duct 39 so that the burner 6 portion is located in front of the net frame 42.
39a, 39b can be fixed to the machine frame with fasteners 45, 46. In this way, the outside air breeze 42 has a relatively large opening area.
Which is introduced from the burner 6 and bypasses the outer peripheral portion of the burner 6 and is transferred to the duct 39 having a narrowed opening area, and the flow velocity is increased at the inlet of the duct 39 ((Fig. 9c). The flow velocity may be gradually increased in consideration of the effect of the burner 6 or the effect of the burner 6 may be ignored).

The fuel valve 29 receives a fuel supply signal from a control mechanism section described later, for example, an on-time variable pulse signal, and controls opening / closing to supply a predetermined amount of fuel to the diffuser through a nozzle 30.
It is a structure that can be dropped on 32 laps.

Reference numeral 47 is a wind pressure sensor for detecting the presence or absence of the introduced outside air, and 48 is a temperature sensor looking above the opening of the upper wall of the duct 39 to detect an abnormal state of flame or an abnormal temperature rise in the hot air chamber 8. sell.

The grain circulation system including the grain elevator 5 and the upper and lower transfer spirals 14 and 15 is rotationally interlocked by a circulation system motor 50 fixed to the upper side wall of the frame of the grain elevator 5. A shaft of the upper transfer spiral 15 is rotationally interlocked with a drive belt 51 on the motor 50 drive shaft, and a pulley (not shown) shaft for winding the bucket belt of the grain elevator 5 is rotationally interlocked with this shaft. The lower transfer spiral 14 is interlockingly connected to a pulley (not shown) shaft under the grain elevator 5 via a transmission belt 52.

In addition, the delivery valve 13, 13 by the valve motor 53,
The suction fan 9 has a structure in which the fan motors 54 rotate independently of each other.

Reference numeral 55 is a flexible discharge pipe that communicates with the opening of the transfer gutter 16 on the transfer start end side through an opening / closing shutter (not shown).

56 is a stake-in hopper.

FIG. 7 is a block circuit diagram showing the arithmetic control unit (CPU) 5
7. The drying control is performed by the microcomputer composed of memory and so on. That is, the CPU 57
Drying, discharging, stopping, etc. operation switches 58, 59, 60, 61 O
N, OFF signals, setting signals of the overhang amount setting switch 62 and the stopped moisture value setting switch 63, signals from the abnormality sensor 64 (for example, the air pressure sensor 47 and the temperature sensor 48), or the hot air temperature sensor 65 and the moisture meter 66. Each output signal from the like is input. On the other hand, ignition heater 34, fuel pump 28, fuel valve 29
The burner 6 drive system signal, drive signals for the circulation system motor 50, the valve motor 53, the fan motor 54, and the like are output. 67 is an A / D converter, and 6 is an input / output interface.

The operation of the above example will be described.

When a predetermined amount of grain is put in the storage tank 2 and the amount setting switch 62 and the stop moisture setting switch 63 are set to predetermined values, the drying switch 59 is turned on.
Works. Here, the burner 6 is a fuel supply amount determined based on the outside air temperature condition and the setting of the above-mentioned amount of expansion, that is, a valve on-time signal and receives and burns, and the nozzle 30
The fuel supplied from the end drops onto the peripheral surface of the diffuser 32, and is transferred along the inner peripheral surface of the vaporization cylinder 26 along with the combustion air blown by the fan 21 while being atomized. The ignited fuel is jetted from the outlet (not shown) to the front of the combustion board 27, and is burned by the ignition action of the ignition heater 34. Once the combustion state occurs, the outer periphery of the vaporization cylinder 23 at the center of the combustion cylinder 26 is warmed by the flame and vaporizes (gasifies) the atomized fuel that is continuously supplied, and this vaporized fuel passes from the rear surface of the combustion plate 27 through the ejection port. It is to eject and continue combustion.

The combustion flame enters the duct 39, and on the other hand, the outside air breeze generated by the suction fan 9 and entering from the net frame 42 of the wind tunnel 7 is the burner 6
It passes through the outer periphery of the part and enters the duct 39 to combine the flames and turn them into hot air. At this time, at the inlet of the duct 39, that is, in the vicinity of the leading edge b of the burner combustion cylinder 26, the ventilation area is narrowed and the outside air flow velocity is slightly accelerated. Therefore, after passing through the outer periphery of the burner 6, the combustion cylinder 26 is suddenly opened at the front. Even in this state, the generation of the vortex flow is delayed, and the generation of the vortex flow on the front surface of the combustion cylinder 26 can be suppressed. Therefore, the vaporizing cylinder without disturbing the combustion flame
23 Good heating effect.

The hot air generated at the duct 39 part, that is, at the inlet side of the hot air chamber 8 is distributed before and after the hot air chamber 8 and passes through the grain flow-down passages 12 and 12 and the exhaust chamber 11
Is discharged to the outside of the machine. In the meantime, the fallen grain is dried.

Grains that have passed through the flow-down passages 12 and 12 are collected in the grain collection chamber 4 and are returned to the storage tank 2 again under the respective transfer actions of the lower transfer spiral 14, the fried machine 5, and the upper transfer spiral 15. Grains are gradually cooled in the tank 2.

By repeating the above drying process, the drying work is automatically stopped when the moisture value measured periodically reaches the initially set stop moisture value, the motors of all parts are turned off, and the fuel supply signal to the burner 6 is also cut off. Turn off.

In the burner 6 according to the present embodiment, the combustion tube 26 approaches the duct 39 and the duct 39 is installed in the inlet side of the hot air chamber 8 so that the front-rear length of the wind tunnel 7 protruding from the machine casing 1 is increased. Can be shortened, which is advantageous for miniaturization.

Further, the distance c between the combustion cylinder 26 of the burner 6 and the inlet of the duct 39 is made to be closest to suppress the generation of eddy currents on the front surface of the combustion cylinder 26 so that the heating state of the combustion flame to the vaporization cylinder 23 is not impaired. Although it is possible to secure the stabilization of the combustion state, it is confirmed that the combustion amount of the burner 6, in particular, the stable combustion of the minimum combustion amount in the case where the combustion amount can be changed to a large or small value. However, it is good to set it appropriately.

In this embodiment, the flow velocity of the introduced outside air flow at the inlet of the duct 39 is increased so that the opening area of the duct 39 is narrowed. However, separate flow promoting members may be provided.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a side sectional view of an essential part, FIG. 2 is a plan view thereof, FIG. 3 is a perspective view of the essential part, and FIG. 4 is a side sectional view of a burner. Figure, Figure 5 is the front view,
FIG. 6 is an overall perspective view, FIG. 7 is a sectional view thereof, FIG. 8 is a block diagram, and FIGS. In the figure, 1 is a machine frame, 6 is a burner, 7 is a wind tunnel, 8 is a hot air chamber,
9 is a suction fan, 11 is an exhaust chamber, 12 and 12 are grain flow passages, 1
Reference numeral 8 is a substrate, 23 is a vaporization cylinder, 26 is a combustion cylinder, 27 is a combustion plate, 39 is a duct, and 42 is a net frame.

Claims (1)

[Claims] 1. A vaporization cylinder 23 for vaporizing a liquid fuel that internally circulates in proximity to a flame is positioned at a substantially central portion, and a combustion cylinder 26 for burning the vaporized fuel ejected from a combustion disc 27 is provided. Is provided in front of the burner 6, which is provided with a duct 39 for converging the flow velocity of the air flow from the back side or the side of the burner 6 with the air flow and the burner 6 flame.
A hot air generator provided with the front edge of 26 close to the entrance of duct 39.