JP3917785B2 - Hot air generator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot air generator, and more particularly, to a hot air generator suitable for a supply source of hot air for melting snow using kerosene as a fuel, which is used in a snow melting device of a rail point for a railway.
[0002]
[Prior art]
An example of a hot air generator used as a conventional hot air supply source for melting snow is shown in FIG. The AC motor 1 is disposed in front of the outer housing 6 shown in the figure, and the blower 2 and the fuel pump 10 are driven to rotate on both sides of the rotating shaft. The blower 2 rotates with a predetermined interval between the blower 2 and feeds combustion air guided by the air guide 20 and blown air passing between the outer housing 6 and the conversion chamber 5.
[0003]
The fuel pump 10 also starts rotating together with the blower 2, the fuel is pressurized, and the solenoid valves 24 and 25 are opened, whereby the fuel is sprayed into the conversion chamber 5 from the tip of the nozzle 11. Next, when the transformer 22 is energized, discharge starts at the tip of the plug 13 and ignites in the conversion chamber 5 to start combustion.
[0004]
Combustion gas is discharged from the tip of the conversion chamber 5 and merged with the air for blown air to become enormous hot air and is discharged from the tip of the outer housing 6. Note that the completion of ignition and the start of combustion is detected by the frame sensor 14 composed of CdS, and energization to the transformer 22, that is, the discharge of the plug 13 is stopped.
[0005]
Combustion is controlled by two-stage switching between Hi and Lo. That is, by closing the solenoid valve 24, the fuel is decompressed through the orifice 23 of the bypass circuit, and the Lo operation is performed by controlling the solenoid valve 21 to adjust the flow rate of the combustion air. In the Hi operation, the solenoid valve 24 is opened, and the solenoid valve 21 is also controlled to increase the flow rate.
[0006]
[Problems to be solved by the invention]
The above-described hot air generator has a problem that since the wind pressure of the blower 2 that sends combustion air and blowing air is low, the change in the amount of air due to fluctuations in piping resistance is large, and stabilization of combustion performance is difficult. In addition, since the switching between Lo operation and Hi operation is performed mechanically, mechanical drive parts are required, the structure is complicated, and variations such as flow rate and pressure become large, and fine control is not possible. was there.
[0007]
Furthermore, since the functional parts are dispersedly arranged and it is difficult to disassemble the heater body, it is impossible to repair the heater body on the spot, and the heater body must be replaced in the event of a failure. And since it is heavy and has large dimensions, it cannot be transported by one person, making maintenance difficult.
[0008]
In addition, as a safety device, there is only a flame sensor that detects non-ignition and combustion interruption, and there is a problem that even if some trouble occurs, an abnormality cannot be detected as long as combustion continues.
[0009]
The present invention has been made in view of the above points, and it is an object of the present invention to provide a hot-air generator that can stably perform combustion control with few mechanical drive components.
[0010]
Another object of the present invention is to provide a hot air generator that is compact and light in weight, is easy to maintain, and can reliably detect abnormal situations.
[0011]
[Means for Solving the Problems]
In the hot air generator of the present invention, a burner head incorporating a combustion blower, a fuel pump, a fuel injection nozzle, an ignition plug, and an igniter is attached to a conversion chamber with a coupling and can be attached and detached with one touch.
[0012]
In the hot air generator, the rotation of a DC motor that drives the combustion blower is controlled by PWM control using a microcomputer and a hall sensor, and the fuel pump is an electromagnetic pump with a regulator and a pressure switching valve built-in. The stage combustion control is performed stably.
[0013]
A hot air generator for melting snow according to the present invention is a coupling of a burner head incorporating a functional part for performing ignition and combustion operations , including a combustion blower, a fuel pump, a fuel injection nozzle, an ignition plug and an igniter, to a conversion chamber. It can be attached and detached with one touch.
[0014]
Further, in each of the hot air generators, the burner is controlled by a DC power source by using an AC-DC converter.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the hot air generator which is an Example of this invention is demonstrated based on drawing. FIG. 1 is a schematic sectional view showing a hot air generator according to an embodiment of the present invention. The AC motor 1 is disposed in front of the outer housing 6 shown in the figure, and the blower 2 is attached to both sides of the rotating shaft thereof to be driven to rotate. The blower 2 rotates with a predetermined distance between the blower 2 and the blower air passing between the outer housing 6, the burner head 4 and the conversion chamber 5.
[0016]
A DC motor 7 is housed in the burner head 4, and a Wesco pump type blower 8 having a high wind pressure is fixed to the rotating shaft thereof. By driving the DC motor 7, the Wesco pump type blower 8 rotates and blows air, and the combustion air passes through the burner head 4 and is supplied into the conversion chamber 5.
[0017]
The rotational speed of the DC motor 7 is detected by a hall sensor 9, and the rotation of the DC motor 7 is controlled at a predetermined speed by PWM control of a heater control unit (HCU) incorporating a micro computer. The burner head 4 further contains a fuel pump 10 (electromagnetic pump) incorporating a regulator valve and a pressure switching valve.
[0018]
When the fuel pump 10 pressurizes the fuel, the fuel is sprayed into the conversion chamber 5 from the tip of the nozzle 11. Next, by driving the igniter 12 built in the burner head 4, discharge starts at the tip of the plug 13, ignites in the conversion chamber 5, and combustion starts.
[0019]
Combustion gas is discharged from the tip of the conversion chamber 5 and merged with the air for blown air to become enormous hot air and is discharged from the tip of the outer housing 6. The ignition / combustion is detected by a frame sensor 14 made of a phototransistor, and the driving of the igniter 12 is stopped by the HCU, and the discharge of the plug 13 is stopped. The HCU controls combustion by two-stage switching between Hi and Lo. That is, in the case of Hi operation and Lo, the HCU controls the rotation speed of the DC motor 7 to each predetermined speed, and controls the fuel pump 10 to each predetermined pressure.
[0020]
A pressure switch 15 is attached to the outer housing 6, and the pressure switch 15 detects the pressure inside the main body, thereby making it possible to detect the blockage of the suction duct and the failure of the AC motor 1. Further, a thermostat 16 is attached to the burner head 4, and the thermostat 16 detects the surface temperature of the burner head 4, thereby making it possible to detect the blockage of the suction / discharge duct and the failure of the AC motor 1. The HCU can safely stop the device.
[0021]
The burner head 4 houses all functional parts (DC motor 7, Hall sensor 9, fuel pump 10, nozzle 11, igniter 12, plug 13, frame sensor 14 and thermostat 16) except the AC motor 1 and the pressure switch 15. In a normal failure, the burner head 4 can be repaired only by replacing it.
[0022]
The burner head 4 can be easily removed by removing the V-band coupling 17 and separating it from the conversion chamber 5, and removing the one-touch coupling 18 and separating it from the fuel line. In this way, by integrating related parts that have been distributed in the past into a unit, the main body is reduced in size and weight, and maintenance is facilitated.
[0023]
【The invention's effect】
According to the hot air generator of the present invention, the influence of the pipe resistance for intake air and hot air blowing on the combustion performance is minimized, and combustion with high pipe resistance is possible.
[0024]
Further, the two-stage combustion control of Hi and Lo is easily and stably performed, and mechanical operation parts such as a solenoid valve for controlling the air flow and the fuel pressure are reduced.
[0025]
In addition, by incorporating most of the functional parts into the burner head and making it into a unit, the main body is reduced in size and weight, and the burner head can be replaced on-site, reducing the time required for repair work. It was. And it was possible to reduce the number of repair personnel by eliminating the need to transport the main body for repair. Safety has also been improved by installing a pressure switch and thermostat.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a hot air generator that is an embodiment of the present invention.
FIG. 2 is a schematic sectional view showing a conventional hot air generator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 AC motor 2 Blower 3 Casing 4 Burner head 5 Combustion chamber 6 Outer housing 7 DC motor 8 Wesco pump type blower 9 Hall sensor 10 Fuel pump 11 Nozzle 12 Igniter 13 Plug 14 Frame sensor 15 Pressure switch 16 Thermostat 17 V Pand coupling 18 One-touch coupling 20 Air guide 21 Solenoid valve 22 Transformer 23 Orifice 24, 25 Solenoid valve

Claims (4)

A burner head that incorporates functional parts that perform ignition and combustion operations, consisting of a combustion blower, fuel pump, fuel injection nozzle, ignition plug, and igniter, is attached to the conversion chamber with a coupling, and is detachable with one touch. A hot air generator for melting snow . The rotation of the DC motor for driving the combustion blower is controlled by PWM control using a microcomputer and a hall sensor, and the two-stage combustion control is stably performed using the electromagnetic pump with a regulator and a pressure switching valve as the fuel pump. The hot air generator according to claim 1, wherein 3. The hot air generator according to claim 1 or 2, wherein a pressure switch for detecting the blockage of the suction duct and the stop of the blower for blowing is attached to the outer housing, and a thermostat for detecting overheating of the equipment is attached to the burner head. 4. The hot air generator according to claim 1, wherein the burner is controlled by a DC power source by using an AC-DC converter.

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