JP2605931B2 - Liquid fuel combustion device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid fuel combustion device used for a hot air heater or the like.

[Prior Art] FIG. 4 is a cross-sectional view showing a configuration of a conventional liquid fuel combustion device used for a hot air heater, in which 1 is a carburetor,
2 is a vaporization chamber, 3 is a throat, 4 is a preheater, 5 is an oil supply pipe made of a material having low thermal conductivity, 6 is a jet nozzle,
6a is a nozzle hole of the ejection nozzle 6, 7 is a connection pipe connecting the vaporization chamber 2 and the ejection nozzle 6, 8 is a needle pipe, 9
Is a needle, 10 is a solenoid valve, 11 is a valve mechanism, 12 is a thermistor that detects the temperature of the carburetor 1, 13 is an air intake hole that takes in primary air, 14 is an oil feed pipe, 15 is an oil supply pump, and 16 is an oil pan. , 17 is a cartridge tank, 18 is a cartridge tank
17 is a filler cap, 19 is a cap for opening the filler cap 18, 20 is a heat shield plate, 21 is a combustion cylinder, 22 is a carburetor cover covering the periphery of the carburetor 1, 23 is a packing, and 24 is a vaporizer. Vaporizer mounting legs that support the vessel cover 22, 25 is a wind tunnel, 26 is a blower, 27
Is a flame plate, 28 is a flame, 29 is a combustion gas, and 30 is a casing.

Next, the operation will be described. An operation switch (not shown) is turned on, and the preheater 4 is energized to preheat the vaporizer 1 to a temperature required to vaporize the liquid fuel.

When the preheating of the vaporizer 1 is completed, the thermistor 12 detects this and starts operation. The refueling pump 15 operates, and the liquid fuel is supplied from the oil pan 16 via the refueling pipe 14 and the refueling pipe 5 to the vaporizing chamber 2. And heated in the vaporization chamber 2 to be vaporized into a vaporized gas.

When the vaporization chamber 2 is sufficiently filled with the vaporized gas, the solenoid valve 10 is opened to shift to the original combustion operation,
Fuel gas is ejected from the nozzle hole 6a of the ejection nozzle 6.

As for the fuel gas ejected from the nozzle hole 6a, a certain amount of primary air determined by the nozzle hole diameter and the throat diameter by the ejector effect is sucked from the air intake hole 13 to be a mixed gas having a constant primary air ratio.

Then, the mixed gas is ejected from the flame holes provided in the flame hole plate 27 into the combustion cylinder 21 and ignited by an appropriate ignition source (not shown) to form a flame 28 to become a high-temperature combustion gas 29. .

The high-temperature combustion gas 29 rises in the combustion tube 21 and mixes with the cool air sent from the blower 26 when it comes out of the combustion tube 21 to become hot air, and passes through the wind tunnel 25 from a hot air outlet (not shown). Discharged forward, which heats the room.

FIG. 5 shows a state of the conventional apparatus at the time of weak operation.
This shows a state in which the calorific value is extremely reduced.

In this state, the temperature of the refueling pipe 5 increases because the amount of heat lost by the fuel flowing in the pipe decreases, while the amount of heat transferred from the outside increases because of a constant amount, and finally the vaporization temperature of the fuel (minimum evaporation rate) ), And vaporizes in the oil supply pipe 5.

A in the figure indicates a liquid phase of the fuel, which is changed to a gas phase D at a joint C of the fuel supply pipe 5 by external heat (arrow B). In this state, the vaporization speed is high, and the vaporization sound becomes loud. Also, during weak operation, the frequency of the refueling pump 15 is set low, so that the supply of fuel is intermittent,
An unpleasant intermittent vaporization sound is generated and the cheeks pulsate.

[Problems to be Solved by the Invention] In the conventional liquid fuel combustion apparatus as described above, in a certain calorific value range, vaporization is performed in the vaporization chamber 2 by receiving heat from the vaporizer 1. When the calorific value of the combustion device is significantly reduced, the amount of latent heat of vaporization is reduced, and the balance of heat required for vaporization is lost, and vaporization is performed in the oil supply pipe 5 before the vaporization chamber 2.

Further, in the region where the calorific value is small, the frequency of the refueling pump 15 is low, and the supply of fuel is intermittent. Therefore, when vaporization is performed in the refueling pipe 5, an unpleasant intermittent vaporizing sound is generated. There was a problem.

The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a device that prevents fuel from being vaporized in a fuel supply pipe and can supply fuel to a primary vaporization section in a liquid phase. The purpose is.

[Means for Solving the Problems] The liquid fuel combustion apparatus of the present invention supplies a liquid fuel to a heated vaporizer through a fuel supply pipe to vaporize the vaporized fuel, and causes the vaporized gas to be ejected from an ejection nozzle and mixed with air. Ignition and combustion, and the tip of the oil supply pipe is projected into the carburetor and connected, and the vaporizing member is disposed on the outer periphery of the projection, the upper surface of the vaporization member and the tip of the projection of the oil supply pipe The pipes are arranged so that they are almost flush with each other, and the connection between the oil supply pipe and the vaporizer has a double pipe structure consisting of an inner pipe and an outer pipe. An intermediate layer consisting of an air layer is formed between the layers.

[Operation] In the liquid fuel combustion apparatus of the present invention, the connecting portion of the fuel supply pipe to the carburetor has a double pipe structure, and an intermediate layer is provided between the inner pipe and the outer pipe. The temperature of the flow path can be reduced because it is in contact with the low temperature part of
Even in a combustion state having a low calorific value, that is, a low vaporization latent heat, the liquid fuel is prevented from reaching the vaporization temperature before reaching the vaporization chamber.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a main part showing an operating state of a combustion device of the present invention. FIG. 2 is a detailed sectional view of a fuel supply pipe connection portion of the liquid fuel combustion device of the present invention.

In FIGS. 1 and 2, reference numeral 31 denotes an inner tube, the upper end of which is spread like a flange, and the end surface of the flange is fixedly pressed into the outer tube 33 in a sealed state.

The lower end is in contact with the inner surface of the lower end of the outer tube 33. Numeral 34 denotes a middle layer composed of an air layer provided between the inner pipe 31 and the outer 33, and these constitute the oil supply pipe 5. The oil supply pipe 5 protrudes to substantially the center of the vaporizing chamber 2, and the outer surface of the protruding portion is in contact with the vaporizing member 32. Further, an oil feed pipe 14 is joined below the oil feed pipe 5, and is connected to an oil feed pump 15.

Note that an aluminum alloy having good heat conduction surrounding the vaporization chamber 2 is not in contact with the vaporizer 1 junction portion of the oil supply pipe 5.
A certain space is provided.

 Next, the operation will be described.

FIG. 2 shows a state of the embodiment of the present invention at the time of weak operation.

The refueling pipe 5 has a double pipe structure of an inner pipe 31 and an outer pipe 33, which are joined at upper and lower ends having a low temperature, so that the temperature rise due to heat from the outside (arrow B) is extremely low. It is suppressed.

Therefore, the fuel does not vaporize inside the inner pipe 31,
The liquid phase A reaches the vaporizing member 32.

In the actual measurement example of this embodiment, at the center of the oil supply pipe 5 in FIG.
200 ° C to 240 ° C, the inner tube 31 is 120 ° C to 150 ° C, and if the fuel is kerosene, its fractionation properties are the initial boiling point 150 ° C and the end point 2
Since the temperature is 70 ° C. or higher, it is understood that vaporization in the inner tube 31 is reliably prevented.

An intermediate layer consisting of an air layer is provided between the inner pipe 31 and the outer pipe 33.
34 are provided to increase the heat insulation effect. Furthermore, since the upper end surface and the lower end of the inner pipe 31 are joined to the outer 33 in a sealed state, the fuel does not flow into the intermediate layer 34. In the above embodiment, the inner pipe 31 and the oil feed pipe 14 are separate parts, but they may be integrally formed as shown in FIG. In short, it is only necessary to prevent the fuel from flowing into the gap between the outer pipe 33 and the inner pipe 31 by sealing the upper end face of the outer pipe 33 and the inner pipe 31, and the upper end face of the outer pipe 33 is swaged or the like. The same effect can be obtained by reducing the diameter. Further, since the tip of the oil feed pipe 14 can be left as a straight pipe, the cost of the apparatus can be reduced.

[Effects of the Invention] As described above, according to the present invention, the tip of the oil supply pipe is protruded into the carburetor and the vaporizing member is disposed on the outer periphery of the protruding portion. The oil falling out of the oil supply pipe is instantaneously diffused without stagnation at the oil supply pipe tip, so that it can be smoothly vaporized, reducing tar production and reducing It is possible to prevent vaporization of the liquid fuel in the fuel supply pipe during operation, prevent occurrence of abnormal noise, and obtain a combustion device with stable quality.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an essential part of a liquid fuel combustion apparatus according to an embodiment of the present invention in an operating state, FIG. 2 is a detailed cross-sectional view of a fuel supply pipe connection portion of the apparatus, and FIG. FIG. 4 is a cross-sectional view of a conventional device, showing an example, and FIG. 5 is a detailed cross-sectional view of an oil supply pipe connection portion of the conventional device. In the figure, 1 is a vaporizer, 5 is an oil supply pipe, 6 is a jet nozzle, 31 is an inner pipe, 33 is an outer pipe, and 34 is an intermediate layer. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. An oil supply pipe supplies a liquid fuel to a heated vaporizer and vaporizes the vaporized fuel. The vaporized gas is ejected from an ejection nozzle, mixed with air to ignite and burn, and a tip end of the oil supply pipe. Are connected by projecting them into the carburetor, and a vaporizing member is arranged on the outer periphery of the projecting portion, so that the upper surface of the vaporizing member is substantially flush with the tip of the projecting portion of the oil supply pipe. And
The connecting portion between the oil supply pipe and the vaporizer has a double pipe structure composed of an inner pipe and an outer pipe, and this double pipe configuration has an intermediate layer formed of an air layer between the outer pipe and the inner pipe. A liquid fuel combustion device, comprising: