JPS6330011Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a liquid fuel combustion device that vaporizes and burns liquid fuel, particularly kerosene. Conventionally, a gas chamber is formed between a combustion tube and a combustion disk disposed on the inner periphery thereof, and a vaporization tube whose inside communicates with the gas chamber is rotatably provided at the central open end of the gas chamber. A device in which a large number of flame holes are bored in multiple stages in a plate is generally known. However, conventional combustion devices of this type have a constant combustion capacity. When the combustion capacity is switched and burned in multiple stages or steplessly, various problems such as the generation of combustion noise occur when the pressure difference between the inside and outside of the flame hole is extremely increased. For this reason, for example, when switching the combustion capacity to four stages for combustion, the pressure difference between the inside and outside of the flame hole is relatively low.
It must be designed to burn while maintaining the level between mmAq and 6 mmAq. For this reason, when the diameter of the flame hole is increased, especially when the combustion capacity is small, the flame enters the inside of the flame hole, causing combustion in a so-called flashback state. Therefore, the diameter of the flame hole should be approximately 1.0 mm to 3.2 mm. Therefore, if the ratio between the minimum combustion amount and the maximum combustion amount is increased, the load on the flame hole when burning at the maximum combustion amount increases.For example, as shown in Figure 3, the minimum combustion amount is 0.6l/hr. When the maximum combustion amount is set to about 1.8 l/hr, the minimum flame hole load is kept at about the usual 6.4 Kcal/mm ² hr, but the maximum flame hole load is 19.7 Kcal/mm ² hr, which is almost the same. The load is three times the normal flame hole load, and in such a case, the flame burns in a so-called lift state where the flame burns at a position away from the combustion disk surface, making the combustion unstable. The purpose of the present invention is to provide a liquid fuel combustion device that can change the amount of combustion per unit time in multiple stages, and which can always achieve stable combustion. A gas chamber 3 is formed between the cylinder 1 and a combustion disk 2 disposed on the inner periphery thereof, and a vaporizing cylinder 4 whose inside communicates with the gas chamber 3 is rotatably provided at the central open end of the gas chamber 3. In a type in which a large number of flame holes 5 are bored in the combustion plate 2 in multiple stages, the diameter of the flame hole 5 is A gap exists between the inner periphery of the combustion disk below the flame hole 5 and the combustion disk 2 within the area of a semicircle with a radius of 1/4 of R and a semicircle with a radius of diameter R. The flame holding plate 6 facing the flame holding plate 6 faces the flame holding plate 6. In the illustrated embodiment, a hollow casing 7 is attached to the lower surface of the combustion tube 1, an electric motor 8 is attached inside the casing 7, and a rotating shaft 9 that stands up upward is protruded from the electric motor 8. The carburetor 1 is supported on the upper end of the motor 8, and a turbo fan 10 is attached to the lower end of the electric motor 8 to form an air supply chamber 11. and the air supply chamber 11, and a fume chamber 13 provided near the central opening of the gas chamber 3 and the air supply chamber 11 are connected by a plurality of connecting pipes 14 to supply air to each. did. In the drawing, reference numeral 15 indicates a cold air discharge port provided in the blow chamber 13, reference numeral 16 indicates a fuel diffusion tube attached to the upper inner end of the vaporization tube 4, and reference numeral 17 indicates a fuel supply pipe facing this. Next, the operation of this device will be explained. The combustion is no different from the conventional example, and the fuel initially scattered from the scattering gap on the lower outer periphery of the carburetor cylinder 4 to the combustion chamber 18 formed on the inner periphery of the combustion plate 2 is sent to the ignition plug facing into the combustion chamber 18. 19 and combusts, the combustion heat heats the vaporization tube 4, and the fuel supplied into the vaporization tube 4 is heated and vaporized to form the reverse air chamber 1.
It is sent into the gas chamber 3 together with the air supplied from the gas chamber 1, and is ejected from the flame hole 5 to be gasified and burned. Such combustion is not particularly different from conventional combustion. In such a case, the discharge capacity of the electromagnetic pump 20 connected to the fuel supply pipe 17 is switched to, for example, four stages, and a damper (not shown) is provided at the intake port of the air supply chamber 11 in conjunction with the switching operation. For example, as shown in Figure 3, the fuel supply amount is changed to 0.6l/hr, 0.8l/hr, 1.3l/hr, and 1.75l/hr.
When switching to 4 stages of hr and switching the mixed gas of fuel and air to 1 mmAq, 1.2 mmAq, 1.7 mm Aq, 5 mm Aq and burning, for example, the flame hole diameter is 1.8 mm, the number of rows is 72, the number of stages is 4.
When burning in a ^{combustor of}
hr and 14.1Kcal/mm ² hr, the maximum is 19.7Kcal/mm ² hr, and especially when burning at the maximum combustion amount, the flame hole load is three times the flame hole load that is normally considered, and this causes the flame to burn away from the combustion plate 2. The fuel burns in a so-called lifted state, resulting in unstable combustion and furthermore, a state in which combustion cannot be sustained. However, when the flame holding plate 6 was placed in front of the lowest flame hole 5, the degree to which such inconvenience occurred could be significantly reduced as shown in the following table.

【table】

[Table] In the above table, ○ indicates normal combustion, △ indicates a state where there is some lift, and × indicates a state where the flame cannot be maintained due to lift.
The experimental results are shown using the metal plate burner shown in FIG. It was calculated by dividing by the hole area. The reason why such a good result can be obtained by providing the flame holding plate 6 is that the lowermost flame is suppressed by the flame holding plate 6, and also because of the secondary radiation of heat by the flame holding plate 6. It is thought that the mixture of fuel and air injected from the flame hole 5 is heated and its combustion speed increases, thereby eliminating the so-called lift phenomenon. It is believed that this is because the flame at the lowest stage is guided upward by the flame holding plate 6 and acts on the flame from the upper flame hole 5 to maintain it in a direction for stable combustion. The shape of the flame holding plate 6 may be a slanted plate that is inclined inward and upward as shown in FIGS. It may also be a vertical plate that extends upward from the lower surface of the flame hole 5 of the combustion plate 2 that is disposed oppositely. As described above, according to the present invention, in the above-mentioned liquid combustion device of the type that vaporizes and burns liquid fuel and switches the amount of combustion per unit time in multiple stages, the By arranging a flame holding plate 6 that projects obliquely upward and inward from the inner periphery of the combustion plate in front of the lower flame hole 5, the lower flame can be suppressed even when the combustion capacity per unit time is increased. By suppressing the flame from the hole 5, it is possible to suppress the flame that is on the verge of lift and achieve stable combustion.
The flame is maintained in the direction of stable combustion, and as a result, it is possible to obtain a device that burns stably at all times in any combustion state in a device that performs combustion by switching the amount of combustion per unit time in multiple stages. There is.

[Brief explanation of the drawing]

Fig. 1 is a cutaway side view of one example of implementing the present invention;
3 is a diagram corresponding to FIG. 2 showing a modification thereof, and FIG. 4 is a diagram showing the relationship between combustion amount and gas chamber pressure. 1... Combustion tube, 2... Combustion plate, 3... Gas chamber,
4... Vaporizing tube, 5... Flame hole, 6... Flame holding plate.

Claims (1)

[Scope of utility model registration request] A gas chamber 3 is formed between the combustion tube 1 and a combustion disk 2 disposed on the inner periphery thereof, and a vaporization tube 4 whose interior communicates with the gas chamber 3 is rotatably provided at the central open end of the gas chamber 3. In a type in which a large number of flame holes 5 are bored in the combustion plate 2 in multiple stages, the flame hole 5 is located in front of the lowest flame hole 5 and centered on the upper end of the flame hole 5. A gap is created between the inner periphery of the combustion disk below the flame hole 5 and the combustion disk 2 in the area of a semicircle with a radius of 1/4 of the diameter R and a semicircle with a radius of the diameter R. A liquid fuel combustion device comprising a flame retaining plate 6 and a flame retaining plate 6 facing each other.