JPH0476301A - Liquid fuel burner - Google Patents

Abstract

PURPOSE:To prevent the fuel from being vaporized in a supply fuel pipe and supply in the state of liquid phase the fuel to a proper vaporization section by constructing the section of connection of a supply fuel pipe to a carburetor in a double pipe construction and providing an intermediate layer between the inner pipe and outer pipe and connecting the inner pipe to the section of the outer pipe where the temperature is low. CONSTITUTION:A supply fuel pipe 5 is constructed in a double construction which has an inner pipe 31 and outer pipe 33, and these pipes are connected to each other at the upper ends and lower ends where the temperature is low. Because of this construction the temperature rise due to the heat from outside is kept as low as possible. Accordingly in the conditions of weak operation the fuel is not vaporized inside the inner pipe 31 and it reaches a vaporization member 32 in liquid phase. Further, between the inner pipe 31 and outer pipe 33 an intermediate layer 34 which consists of an air layer is provided and the adiabatic effect is thereby raised. Furthermore, the upper end face and the lower end face of the inner pipe 31 are airtightly connected to the outer pipe 33 so that the fuel never flows into the intermediate layer 34.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a liquid fuel combustion device used in hot air heaters and the like.

[Prior Art] Fig. 4 is a sectional view showing the configuration of a conventional liquid fuel combustion device used in a hot air heater.
is a vaporization chamber, 3 is a throat, 4 is a preheater, 5 is an oil supply pipe made of a material with low thermal conductivity, 6 is a jet nozzle, 6
a is a nozzle hole of the ejection nozzle 6, 7 is a connecting pipe connecting the vaporization chamber 2 and the ejection nozzle 6, 8 is a needle pipe, 9
is two dollars, 10 is a solenoid valve, 11 is a valve mechanism, 12 carburetor 1
13 is an air intake hole that takes in primary air; 14 is an oil pipe; 15 is a fuel pump; 1
6 is an oil pan, 17 is a cartridge tank, 18 is a fuel filler cap of the cartridge tank 17, 19 is a base for opening the mouth of the fuel filler cap 18, 20 is a heat shield plate, 21 is a combustion tube, and 22 is a fuel filler cap of the carburetor 1. surrounding vaporizer cover, 23
24 is a gasket, 24 is a carburetor mounting leg that supports the carburetor cover 22, 25 is a wind tunnel, 26 is a blower, 27 is a flame hole plate, 28
29 is the flame, 29 is the combustion gas, and 30 is the casing.

Next, the operation will be explained. Operation switch (not shown)
is turned on, the preheater 4 is energized, and the vaporizer 1 is preheated to the temperature required to vaporize the liquid fuel.

When the preheating of the carburetor 1 is completed, the thermistor 12 detects this and starts operation, and the fuel pump 15 starts operating.
Liquid fuel is sent from the oil pan 16 to the vaporization chamber 2 via the oil supply pipe 14 and the oil supply pipe 5, and is heated and vaporized in the vaporization chamber 2 to become vaporized gas.

Then, when the vaporization chamber 2 is sufficiently filled with 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.

In the fuel gas ejected from the nozzle hole 6a, a fixed amount of primary air determined by the nozzle hole diameter and the throat diameter is sucked through the air intake hole 13 due to the ejector effect, and becomes a mixed gas with a fixed primary air ratio.

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

The high-temperature combustion gas 29 rises up the combustion tube 21 and
When the hot air comes out, it mixes with the cold air sent from the blower 26 to become warm air, which passes through the wind tunnel 25 and is discharged forward through the hot air outlet (not shown), thereby heating the room.

[Problem H to be solved by the invention] In the conventional liquid fuel combustion apparatus as described above, within a certain range of calorific value, vaporization occurs due to heat received from the vaporizer 1.
This is carried out in the vaporization chamber 2, but when the calorific value of the combustion device becomes significantly smaller, the amount of latent heat of vaporization decreases, and the balance of receiving and receiving the heat necessary for vaporization is disrupted.
Vaporization begins to take place inside.

In addition, in a region where the calorific value is low, the frequency of the fuel pump 15 is low and the fuel supply is intermittent, so when vaporization occurs in the fuel supply pipe 5, an unpleasant intermittent vaporization amount occurs. There was a problem.

The present invention has been made to solve the above-mentioned problems, and aims to provide a device that can prevent fuel from vaporizing in the fuel supply pipe and supply fuel in a liquid phase to the original vaporizing section. The purpose is

[Means for Solving the Problems] The liquid fuel combustion device of the present invention includes an intermediate layer between an inner pipe and an outer pipe in the connection portion of the fuel supply pipe that supplies liquid fuel to the vaporizer with the vaporizer. It has a double tube structure.

[Function] In the liquid fuel combustion device of the present invention, the connecting portion of the fuel supply pipe to the vaporizer has a double pipe structure, and an intermediate layer is provided between the inner pipe and the outer pipe, so that the inner pipe is connected to the outer pipe. The temperature of the flow path can be lowered, and even in combustion conditions with low calorific value, that is, low latent heat of vaporization, the liquid fuel reaches the vaporization temperature before reaching the vaporization chamber. This will prevent it from happening.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of essential parts showing the operating state of the combustion apparatus of the present invention. FIG. 2 is a detailed sectional view of the 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 whose upper end is expanded into a flange shape, and the end surface of this flange is press-fitted onto the outer tube 33 in a sealed state and fixed thereto.

Further, the lower end is in contact with the inner surface of the lower end of the outer tube 33. 34 is an intermediate layer consisting of an air layer provided between the inner tube 31 and the outer tube 33, and these constitute the oil supply pipe 5. The oil supply pipe 5 protrudes to approximately the center of the vaporization chamber 2, and the outer surface of the protrusion is in contact with the vaporization member 32. Furthermore, a fuel supply pipe 14 is connected below the fuel supply pipe 5, and this is connected to the fuel pump 1.
15.

Note that a certain space is provided at the joining portion of the fuel supply pipe 5 to the carburetor 1 so that the aluminum alloy surrounding the vaporization chamber 2 and having good thermal conductivity does not come into contact with it.

Next, the operation will be explained.

FIG. 5 shows the state of the conventional device during weak operation, and shows a state in which the amount of heat generated is extremely reduced.

In this state, the temperature of the fuel supply pipe 5 increases because the amount of heat lost by the fuel flowing inside the pipe decreases and the amount of heat transferred from the outside is constant, and finally reaches the vaporization temperature of the fuel (minimum evaporation rate point). The oil reaches the point where it vaporizes inside the oil supply pipe 5.

A in the figure indicates the liquid phase of the fuel, which is exposed to heat from the outside (
As indicated by the arrow B), the gas phase changes at the joint C of the oil supply pipe 5. In this state, the vaporization speed becomes faster and the vaporizer becomes larger. In addition, during weak operation, the frequency of the fuel pump 15 is set low, so fuel supply becomes intermittent.
A noisy intermittent vaporizer or pulsating flame may occur.

FIG. 2 shows the state of the embodiment of the present invention during weak operation.

The oil supply pipe 5 is a double pipe ellipse with an inner pipe 31 and an outer pipe 33, and these are joined at the lower and lower ends, so that
The temperature rise caused by hot arrow B) from the outside is kept extremely low.

Therefore, the fuel does not vaporize inside the inner tube 31.
The liquid phase A reaches the vaporization member 32 as it is.

In the actual measurement example of this embodiment, 2
00°C to 240°C, and the temperature in the inner tube 31 is 120°C to 150°C. In addition, when the fuel is kerosene, its fractional properties are higher than the initial boiling point of 150°C and the final point of 270°C. It can be seen that vaporization is reliably prevented.

Further, an intermediate layer 34 made of an air layer is provided between the inner tube 31 and the outer tube 33 to improve the heat insulation effect. Furthermore, since the upper end surface and lower end of the inner pipe 31 are joined to the outer pipe 33 in a sealed state, fuel will not flow into the intermediate layer 34. In the above embodiment, the inner pipe 31 and the oil feed pipe 1
4 is made into a separate part, but it may be configured as one piece as shown in FIG.
It is sufficient that fuel is prevented from flowing into the gap between the outer tube 33 and the inner tube 31 by sealing the outer tube 33, and the same effect can be obtained by reducing the diameter of the upper end surface of the outer tube 33 by swaging or the like. . Furthermore, since the tip of the oil pipe 14 can remain straight, the cost of the apparatus can be reduced.

[Effects of the Invention] As described above, according to the present invention, it is possible to prevent the vaporization of liquid fuel in the fuel supply pipe during weak operation, to prevent the generation of abnormal noise, and to obtain a combustion device with stable quality. can

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part of a liquid fuel combustion device 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 same device, and FIG. 3 is another embodiment of the present invention. FIG. 4 is a sectional view of the conventional device, and FIG. 5 is a detailed sectional view of the oil supply pipe connecting portion thereof. In the figure, 1 is a carburetor, 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. Note that the same reference numerals in the figures indicate the same or corresponding parts. Figure 1 Agent Masuo Oiwa (2 others) 3 + Nakatada 1 Figure 4

Claims (1)

[Claims] Liquid fuel is supplied to a heated vaporizer and vaporized, and this vaporized gas is ejected from a jet nozzle, mixed with air and ignited for combustion.The liquid fuel is then placed in a liquid fuel combustion device and supplied to the vaporizer. A liquid fuel combustion device characterized in that a portion of a fuel supply pipe connected to the vaporizer is constituted by a double pipe having an intermediate layer between an inner pipe and an outer pipe.