JPS6311564B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid fuel combustion device applied to a domestic heater, such as an oil fan heater, which mixes combustion exhaust gas with warm air and discharges the mixture indoors. The aim is to broadly improve combustion characteristics.

Conventionally, in this type of home heater, when the combustion amount is varied, the air-fuel ratio tends to become unbalanced.
This had the disadvantage that the combustion control range became narrower.

The present invention eliminates the above drawbacks.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In FIGS. 1 and 2, an outer fire pan 3 is coaxially attached to the upper part of the fuel tank chamber 1, with the core guide cylinder 2 caulked to the fuel tank chamber 1 as the center. A multi-tube burner 4 having multiple pores is placed above the core guide tube 2 and the outer fire pan 3 with a vaporizing element 5 sandwiched therebetween. The vaporizing element 5 is movable up and down, and a suction wick 6 is provided at the bottom. At least a part of the suction wick 6 is constructed so as to be constantly immersed in the fuel 7 in the tank chamber 1, and the fuel is sucked up the suction wick 6 and passed through the vaporization element connected to the upper part. 5 and is vaporized and diffused in the lower part of the double-tube burner 4. Further, vaporization and diffusion of the fuel is promoted by the inflow of fuel air, a part of which is flame-stabilized and combusted in the pores of the twin-tube burner 4, and the rest is burned in the upper part of the two-tube burner 4. The outer periphery of the twin-tube burner 4 is covered with a combustion tube 9. These outer peripheries are further covered by an ejector outer cylinder (used as a blower tube) 10, and a blower plate 11 is attached to the upper part of the combustion tube 9.
through a fan motor 12 and a blower fan 13 mounted on the rotating shaft of the fan motor 12.
However, the combustion tube 9 is attached to the ejector outer tube 10.
It is installed coaxially with. Further, the ejector outer cylinder 10 and the air baffle plate 11 provide a narrowing portion 1.
4. A hot air path 15 is formed by the ejector outer cylinder 10 and the combustion cylinder 9, respectively.

In the above configuration, first, when the vaporization element 5 is set at a predetermined height, the fan motor 12,
After the blower fan 13 rotates and the air sent by the blower fan 13 passes through the constriction part 14,
Air begins to be drawn from the upper part of the combustion tube 9. At the same time, an ignition heater (not shown) is energized and starts to ignite and burn. Combustion exhaust gas is attracted by the negative pressure generated in the throttle section 14, and as a result, combustion air is drawn into the double-tube burner 4, where combustion is performed.

Note that the vaporization element 5 has the following characteristics.
The amount of fuel vaporized from the surface of the vaporization element 5, that is, the amount of combustion, is uniquely determined by the amount of conveying air (amount of inflowing air), the temperature of the conveying air, or the surface area in contact with the conveying air. Further, the amount of combustion exhaust gas induced from the upper part of the combustion tube 9 is determined by the opening area ratio β ² of the throttle part 14.
= (1-du/D) ² (D is the ejector outer cylinder 10
diameter) and the point of use on the P-Q characteristics of the blower fan 13. Further, by increasing the flow velocity of the driving gas after passing through the constriction section 14, which plays a main role in regulating the amount of attraction, the amount of attraction also increases approximately proportionally. Therefore, by changing the P-Q characteristics (for example, rotation speed) of the blower fan 13, the combustion exhaust gas, that is, the amount of suction air can also be changed, and the amount of combustion can be changed. Further, a part of the vaporized fuel is flame-holded and burned in the porous element 5 of the double-tube burner 4, and the remaining vaporized fuel forms a Bunsen-like open flame. As a result,
There is no need to consider the flame hole load due to changes in combustion amount, and it can be adjusted over a wide range. In the combustion device having the above characteristics, the flow of combustion gas in the combustion tube 9 forms a recirculation region in which the flow is upward near the wall of the combustion tube 9 and downward in the center, as shown in Fig. 2. , at the same amount of blown air, the recirculation area also changes depending on the diameter d of the combustion tube 9. That is, as the diameter d of the combustion tube 9 becomes larger, the recirculation area also becomes larger, the flow rate of unused gas, etc. increases, and the exhaust gas during steady combustion becomes bad or has an odor. In order to prevent this, there are methods such as making the combustion tube 9 sufficiently high, but as shown in FIG. 3, when looking at the ratio of the diameter d of the combustion tube 9 to the diameter du of the baffle plate 11, d/du0.55, d/
When du≧0.9, it becomes CO/CO ₂ × 10 ^-3 and the combustion exhaust gas deteriorates. Therefore, this diameter ratio range (0.55<
d/du<0.9) and cleanliness. That is, 0.6≦d/
By setting the diameter d of the combustion tube 9 with respect to the baffle plate 11 so that du≦0.8, the combustion exhaust gas can be made clean when the combustion amount is adjusted over a wide range. Note that since the present invention is directed to a household indoor heater, its size is also limited, and the diameter du of the wind baffle plate 11 is du≦250 mm.
It is. Further, the results shown in FIG. 3 were obtained when the gap between the tightening portions 14 was kept constant.

As described above, the present invention provides a burner whose combustion amount is approximately proportional to the amount of combustion air, a combustion tube that covers the outer periphery of this burner, a wind baffle plate disposed above this combustion tube, and a wind baffle plate. A hot air fan disposed above, a hot air fan, a baffle plate, and a hot air path formed on the outer periphery of the combustion tube that covers the outer periphery of the combustion tube and communicates with the upper end opening of the combustion tube. A constriction part formed between the tube and the blow tube and the baffle plate, which generates negative pressure by the hot air flow discharged into the hot air path from between the tube and sucks in the combustion air and combustion exhaust gas. and a ratio d/du of the diameter du of the baffle plate and the diameter d of the combustion tube with the throttle portion constant.
Since it is a liquid fuel combustion device set at 0.6 to 0.8, it has the following effects.

The ejector structure has a large attraction effect and efficiency, and stable combustion air is sucked and supplied without the hot air flowing back into the combustion tube, making it possible to obtain stable combustion and its characteristics.

The warm air is a mixture of indoor air and combustion exhaust gas at a constant ratio, and is blown into the room as highly uniform warm air.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a liquid fuel combustion device according to an embodiment of the present invention, FIG. 2 is a sectional view of main parts of the liquid fuel combustion device, and FIG. 3 is a wind baffle plate of the liquid fuel combustion device. FIG. 3 is a characteristic diagram showing the combustion exhaust gas with respect to the ratio of the diameter du to the diameter d of the combustion tube. 1... Fuel tank chamber, 4... Dual cylinder burner, 5...
... Vaporization element, 6 ... Suction wick, 9 ... Combustion cylinder, 1
0... Ejector outer cylinder, 11... Wind control plate, 14
...Aperture section.

Claims (1)

[Claims] 1. A burner whose combustion amount is approximately proportional to the amount of combustion air, a combustion tube that covers the outer periphery of this burner, a wind baffle placed above this combustion tube, and a burner placed above this wind buff plate. A hot air fan, the hot air fan, a baffle plate, a blower tube that covers the outer periphery of the combustion tube and that forms a warm air path on the outer periphery of the combustion tube that communicates with the upper end opening of the combustion tube, and this blower tube. and a constriction part formed between the air baffle plate and the baffle plate, which generates a negative pressure by the hot air flow discharged into the hot air path from between the constriction plate and sucks the combustion air and the combustion exhaust gas. A liquid fuel combustion device, wherein the ratio d/du of the diameter du of the baffle plate and the diameter d of the combustion cylinder is set to 0.6 to 0.8 while keeping the ratio d/du constant.