JPS6127650B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides the following advantages:
The present invention provides a combustion device that provides good combustion characteristics.

In a conventional combustion device using a spray nozzle, a flame stabilizer 30 is installed in front of a nozzle 29 provided inside a blower tube 28, as shown in FIG. Generally, a flame stabilizer 30 is provided with circular holes 31 and air holes 32 on the outer periphery to create a negative pressure area on the flame stabilizer 30 to stabilize the flame. It is normal to form a swirler 33 in the flame stabilizing part of 30 to prevent soot from adhering to it and to improve the combustion condition, and in the case of such a combustion device, the combustion supply amount is varied. In this case, even if the mechanism that follows the variable combustion air amount is satisfied, the combustion air velocity and fuel injection velocity in the circular hole 31 on the flame stabilizer 30, the swirler 33, and the air hole 32 on the outer periphery cannot be well balanced. However, it has the drawbacks of incomplete combustion, such as blow-off phenomenon, poor mixing, and generation of large amounts of soot and carbon monoxide.
It had the disadvantage that good combustion characteristics could not be obtained in the entire range of variable combustion amount.

Also, in the combustion device shown in FIG. 5, even if the combustion amount is varied and the air amount is also varied by changing the tap of the blower motor 14', the air jet hole 1 of the middle cylinder 13'
Since the total area of 8' does not change, each air outlet 1
The swirling jet speed of the combustion air from 8' becomes weaker, resulting in poor mixing, making it impossible to form a blue flame, and generating soot and carbon monoxide. It had the drawback of not being able to provide the desired characteristics.

The present invention has been made to improve these drawbacks. In other words, when varying the amount of combustion air at the same time as changing the amount of fuel supplied, the combustion air jetting speed is kept almost constant in any combustion amount range, and it is possible to maintain good performance from the low combustion amount region to the high combustion amount region. This makes it possible to obtain suitable combustion characteristics.

The present invention will be explained below with reference to an embodiment shown in the drawings.

In FIGS. 1, 2, and 3, 1 is a return nozzle as an atomization means, and fuel oil sent from an oil tank 2 is passed through an electromagnetic pump 3 and an oil pipe 4. It is sprayed from the tip of the return nozzle 1. 5 is a proportional control valve that controls the amount of return oil through the return pipe 4A from the return nozzle 1 to vary the amount of combustion. Reference numeral 6 denotes a support cylinder incorporating a return nozzle 1, an oil pipe 4, and an igniter 7, and a can body 10 composed of an inner shell 8 and an outer shell 9.
The tip of the return nozzle 1 and the tip of the ignition device 7 are provided so as to face the combustion chamber 12 through the lower opening 11 of the combustion chamber 1. Reference numeral 13 denotes a middle cylinder erected at the center of the bottom of the combustion chamber 12 in communication with a wind cylinder 17 for supplying combustion air from a blower consisting of a motor 14, a fan 15, and a fan case 16. A large number of air jet holes 18 are provided.

Further, the air jet hole 18 of the middle cylinder 13 is divided into a plurality of parts in the circumferential direction on the concentric inner surface of the middle cylinder 13, and the divided adjacent grooves 34 are arranged alternately at the upper end 35 and the lower end 3.
6 is provided with an inner cylinder 19 closed, and the lower end 36 is closed.
A passage 37 for passing air is provided at the upper end of the closed groove 34, and a communication port 20 between the opening at the bottom of the inner cylinder 19 and the wind cylinder 17 controls the amount of air into the inner cylinder 19. There is a solenoid 21 and a damper 22 that operate in conjunction with the proportional control valve 5.

Reference numeral 23 denotes a cylindrical auxiliary combustion cylinder in which an opening 24 is provided around the middle cylinder 13 at a position that does not contact the inner cylinder 8 to prevent collision of fine particles ejected from the return nozzle 1; 13 to form a mixture vaporization chamber.

25 is a ring that controls the flow and pressure of combustion gas within the combustion chamber 12.

The operation of this embodiment will be explained below.

The difference from conventional combustion devices is that combustion air and fuel particles are supplied separately.

Fuel particles are sucked up from an oil tank 2 by an electromagnetic pump 3, and the pressurized oil is sprayed from a return nozzle 1 via an oil pipe 4, but the amount of combustion can be varied by electrical energy. By changing the valve opening degree of the proportional control valve 5, the spray is returned from the return nozzle 1 through the return pipe 4A, thereby controlling the spray amount.

On the other hand, combustion air is supplied to the wind barrel 1 by a blower consisting of a motor 14, a fan 15, and a fan case 16.
7 into the middle cylinder 13, and is ejected from the air jet hole 18 of the middle cylinder 13, and the amount of fuel supplied is varied in accordance with the amount of combustion air. That is, since the inner cylinder 19, whose details are shown in FIGS. 3A, B, and C, is arranged on the concentric inner surface of the middle cylinder 13 and which periodically divides the air jet holes 18 in the circumferential direction, the combustion amount proportional control is performed. The solenoid 21 in conjunction with the valve 5 opens and closes the communication port 20 on the lower surface of the inner cylinder 19 with the damper 22, thereby controlling the passage to the air jet hole 18. By doing this, the amount of combustion air can be reduced. You can make changes. In this embodiment, the passage to the air nozzle 18 is controlled by dividing it into approximately two parts.
If the number and shape of 9 are further subdivided, more linear air volume control becomes possible.

In the combustion process, fine particles sprayed from the return nozzle 1 pass through the opening 24 of the auxiliary combustion tube 23, mix with a high-speed swirling flow from the air jet hole 18 at the bottom of the middle tube 13, and are ignited by the ignition device 7. Ru. After ignition, the spray particles and the swirling air flow are instantly mixed in the mixing/vaporization chamber between the middle cylinder 13 and the auxiliary combustion cylinder 23, and the evaporation and vaporization of the mixed particles is promoted by the radiant heat of the combustion flame, and the mixture particles are heated to the middle cylinder 13. Vaporization combustion takes place in the upper air injection hole 18 of.

Next, to explain the proportional combustion process, when the combustion amount is high, the damper 22 to the inner cylinder 19 is open as shown in FIG. The air jet speed under the optimum conditions promotes evaporation and vaporization and combustion.
At low combustion rates, the inner cylinder 19
The damper 22 to
Since the swirling air velocity from the start does not change in any way from that during high combustion, good combustion characteristics can be obtained. In the above embodiment, the combustion amount was varied using a combustion device using liquid fuel, but combustion using gas fuel is also possible.

In this way, the present invention has a simple and compact structure that opens and closes one air communication port provided at the bottom of the middle cylinder, and has a large number of air jet holes when changing the amount of combustion air in conjunction with the variable amount of combustion supply. The air can be subdivided in the circumferential and longitudinal directions, and the air mixed with fuel in the vaporization premixing region, the amount of air to the combustion flame, and the ejection speed can be kept constant, allowing for a range from low combustion to high combustion. Good vaporization premix combustion characteristics can be obtained over the range. Also, during the vaporization/premixing process, air is preheated by the radiant heat of the combustion flame, thereby promoting mixing/vaporization.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a combustion device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line B-B' in FIG.
FIG. 3A is a perspective view of the inner cylinder, FIG. 3B is a sectional view showing the high combustion state, and FIG. 3C is a sectional view showing the low combustion state.
FIGS. 4 and 5 are sectional views showing conventional examples. 1... Return nozzle, 11... Opening, 12
... Combustion chamber, 13 ... Middle cylinder, 18 ... Air jet hole, 19 ... Inner cylinder.

Claims (1)

[Claims] 1 comprising a combustion chamber, a variable means for varying the amount of fuel supplied into the combustion chamber, and a middle cylinder provided in the combustion chamber opposite to the fuel supply means and having a large number of air injection holes in the peripheral wall, The air jet hole of the middle cylinder is divided into a plurality of parts in the circumferential direction in the middle cylinder, and the divided adjacent grooves are provided with inner cylinders whose upper ends and lower ends are alternately closed, and the lower ends are closed. A combustion chamber characterized in that a passage for passing air is provided at the upper end of the groove, and a damper is provided for opening and closing a communication port for combustion air into the lower part of the inner cylinder in conjunction with the combustion amount variable means. Device.