JPH0113006B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a liquid combustion device used in a small oil combustion appliance for general household use.

Structure of conventional example and its problems Conventionally, in this type of combustion apparatus, as shown in FIG.
A fuel injection nozzle 4 is provided on the almost concentric axis, and fuel and air are injected into the vaporization cylinder, and the fuel and air are vaporized in the vaporization cylinder.
The mixture was mixed and burned at the flame port 14 provided at the top. The primary air outlet is connected to a blower 9 by an air duct 8, and a control valve 18 is provided in the middle of the air duct to change the cross-sectional area of the air duct and adjust the amount of air blown out from the primary air outlet. . In the above configuration, in order to keep the air-fuel ratio constant, when a large amount of fuel is injected from the fuel injection nozzle, the control valve of the air duct is opened to supply a large amount of combustion air, and when to inject less fuel. teeth,
The control valve is closed to reduce the supply of combustion air. However, in this configuration, since the cross-sectional area of the primary air outlet is constant, when there is a large amount of combustion air, the air flow rate ejected from the primary air outlet is high, and when the amount of air is small, the flow rate is slow. Therefore, when the flow rate of the fuel injected from the fuel injection nozzle is high, the fuel becomes fine and instantly vaporizes in the vaporizing cylinder, and the mixture with the combustion air becomes uniform, resulting in flames. A uniform flame can be created at the mouth, but if the flow velocity is slow, the fuel will not be atomized properly, and the fuel will drip from the nozzle, causing a delay in vaporization in the vaporization cylinder, and One-sidedness in the club,
Pulse combustion occurs, producing soot and combustion noise, which is inappropriate for general household heating equipment. Furthermore, if the primary air jetting port and the combustion jetting nozzle are eccentric, the mixture within the vaporization cylinder becomes uneven, resulting in the generation of odors such as raw gas, resulting in problems such as increased man-hours during assembly.

Purpose of the Invention The present invention has been made in view of the above problems.
The purpose is to improve the fuel atomization condition when the amount of air is low and to provide combustion as a general home heating appliance.

Structure of the Invention In order to achieve the above object, the present invention provides a means for varying the area of the primary air jet at the outlet of the primary air jet, and when the amount of combustion air is large, the cross section of the primary air jet is enlarged. When the amount of air is small, the cross section is made smaller, the ejection flow velocity is kept constant, and the state of the fuel spray is made finer to achieve uniform combustion.

DESCRIPTION OF THE EMBODIMENTS The embodiment will be described below with reference to FIGS. 2 to 4. 1 is a bottomed cylindrical vaporizing cylinder with an open top;
Reference numeral 2 designates a vaporization heater embedded in the vaporization cylinder, and 3 designates a primary air injection port for ejecting combustion air into the vaporization cylinder. 4 has one side opened in the vaporization cylinder on a substantially concentric axis of the primary air outlet, and the other side connected through the pump 5;
A combustion jet nozzle 8 is connected to a fuel pipe 7 connected to an oil tank 6, and an air duct 8 is connected to a primary air jet port and a blower 9 that supplies combustion air. Reference numeral 10 denotes a burner case surrounding the outer periphery of the vaporizing cylinder, and the bottom thereof is connected to the air duct through a cooling pipe 11. Reference numeral 12 denotes a guide body disposed at the upper opening of the vaporizing cylinder, and 13 denotes a burner head that covers the upper opening of the vaporizing cylinder from above the guiding body, and is formed into a sky cylinder. A flame port 14 is formed. 15 is a spark plug. Inside the primary air outlet, a hollow conical variable area valve 16 is slidably attached to guide the fuel injection nozzle. The variable area valve has a conical outer circumference 16a, and is tapered to fit with the outlet of the primary air jet port, and the combustion air is configured to flow through the inner hollow part 16b of the variable area valve 16.
The variable area valve 16 slides around the outer periphery of the fuel injection nozzle by an electromagnet 17 provided outside the air duct, and is engaged with and disengaged from the outlet of the primary air injection port.
The electromagnet moves to separate the variable area valve from the primary air injection port when the amount of fuel being ejected is large, and to engage it when the amount of fuel being ejected is small. Also, variable area valve 1
The cross section of the inner hollow part 6 is smaller than the cross section of the primary air outlet. In the above configuration, the fuel in the fuel tank is sucked up by the pump,
It passes through the fuel pipe and is ejected from the fuel injection nozzle into the vaporization cylinder. On the other hand, the combustion air sent by the blower passes through the duct and is ejected into the vaporization cylinder from the primary air outlet. The ejected fuel is vaporized in the vaporization cylinder, mixed with combustion air, and ejected from the flame port of the burner head 13. This mixed gas is then ignited by a spark discharge from the ignition flag 15 and starts combustion. At this time, when a large amount of fuel is supplied from the pump 5 and a large amount of fuel is ejected from the fuel injection port, the electromagnet of the variable area valve 16 is disconnected from the primary air injection port 3 by the spring 18 as shown in FIG. Reduces flow path resistance of combustion air. Fuel injection nozzle 4
When the amount of jet from the fuel jet nozzle 4 decreases, the electromagnet 17 is turned on as shown in FIG.
and fit with the primary air outlet 3. Therefore, the flow path resistance of combustion air increases, the amount of combustion air injected into the carburetor cylinder decreases, and the air-fuel ratio can be kept constant. At the same time, the air flow is injected into the carburetor cylinder 1 through the inner hollow part of the variable area valve 16 with a small cross section, so the air flow velocity around the fuel injection nozzle 4 decreases even though the amount of combustion air decreases. do not. By keeping the flow velocity around the fuel injection nozzle 4 constant, the state of the spray from the fuel injection nozzle 4 is always made fine and uniform combustion can be obtained.

Further, the variable area valve 16 slides while guiding the outer periphery of the fuel injection nozzle 4 and is fitted with the primary air injection port 3 on the conical surface of the outer periphery. Even if the nozzle is eccentric, the nozzle is automatically corrected to be on the concentric axis of the primary air outlet 3 when fitted. Therefore, it is possible to prevent the occurrence of odor due to uneven mixing due to eccentricity between the primary air jet port 3 and the fuel jet nozzle 4. Furthermore, if the amount of fuel injected is small, the flame at the burner port becomes short and the temperature of the vaporizer cylinder increases, making it easy to cause flashback. Therefore, when reducing the combustion amount, it is necessary to cool the carburetor cylinder. In the present invention, the bottom of the burner case 10 and the middle of the air duct 8 are connected with the cooling pipe 11 to create a bypass path, so when the combustion amount is lowered, the primary air jet port 3 and the variable area valve 16 are not easily fitted. Therefore, the air resistance within the primary air outlet increases, and the amount of air passing through the bypass passage increases, thereby cooling the outer periphery of the vaporizing cylinder.

Effects of the Invention As is clear from the above description of the embodiments, the present invention uses a variable area valve provided in the primary air nozzle to vary the amount of combustion air and maintain a constant air-fuel ratio injected into the carburetor cylinder. In addition, the flow velocity around the fuel injection nozzle can be maintained constant, which prevents uneven combustion and pulsed combustion during low combustion, which was a problem with conventional products, and is suitable for appliances with large fluctuations in combustion amount. In addition to being able to automatically correct the eccentricity of the fuel injection nozzle, there is no need for adjustment during assembly, which has the effect of increasing productivity.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional configuration diagram showing a conventional combustion device, FIG. 2 is a cross-sectional configuration diagram of a combustion device according to an embodiment of the present invention, FIG. 3 is a cross-sectional diagram of the main part of the same device during large combustion, Figure 4 is a sectional view of the main parts of the device during low combustion. 1... Carburizer cylinder, 3... Primary air outlet, 4...
Fuel injection nozzle, 16...Primary air port area variable means (area variable valve).

Claims (1)

[Scope of Claims] 1. A vaporizer cylinder that vaporizes liquid fuel on a wall surface, a primary air outlet that supplies combustion air into the vaporizer cylinder, and a fuel provided approximately on a concentric axis of the primary air outlet. A liquid combustion device comprising a jet nozzle, and a primary air port area variable means provided at an outlet of the primary air jet port. 2. The liquid combustion device according to claim 1, wherein the primary air jet nozzle area variable means guides the fuel jet nozzle and is tapered fitted to the primary air jet nozzle.