JPS60202215A - Liquid fuel combustion device - Google Patents

Abstract

PURPOSE:To increase the varying zone of a combustion amount by varying the area of burner port to a value responding to a change in the combustion amount and making a burner port load constant, by a method wherein a passage extending from an evaporator to plural combustion parts is independently located, and a means for opening and closing the passage is installed. CONSTITUTION:A combustion part 13 is divided into two parts by a partition plate 19, and a passage running from an evaporator 1 to a wire net 12 and plural burner ports of the wire net 12 are formed. Fuel gas fed to the wire net 12 can be shut off by opening and closing an opening hole 20 by means of a valve 22. When a combustion amount is high, a solenoid 23 is brought to an OFF-state to supply the fuel and the air responding to the size of the combustion amount, and the air and the fuel are burnt throughout the whole range of the wire net 12 of the combustion part 13. When the combustion amount is low, the solenoid 23 is brought to an ON-state and this raises the valve 22 to close the opening hole 20. The fuel gas, evaporated through supply of the fuel and the air proportioning the low value of the combustion amount, is prevented from flowing to the upper part of the combustion part 13 because of the opening hole 20 being closed, but flows through the wire net 12 by means of a flow uniformizing cylinder 10. This causes a flame to be formed only at the lower part of the combustion part 13.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a liquid fuel combustion device that vaporizes liquid fuel and burns gas premixed with air at a flame opening.

Conventional structure and its problems Conventionally, this type of liquid fuel combustion device has a heater embedded in the lower part of the vaporizer, and a ventilation passage connected to the blower on the side wall of the vaporizer and a fuel capillary with a nozzle-shaped tip. It is possible to connect it to a fuel pump.

A combustion tube with a flame port is connected to the vaporizer. Fuel is supplied from the tank by the fuel pump to the vaporizer through the fuel tube, where it is gasified on the high-temperature wall, mixed with air, and combusted at the flame port of the combustion tube.

This combustion depends on the speed of the fuel gas flowing out from the flame port,
The combustion speed is balanced at the flame opening, and the flame surface is kept flame-holding, sustaining combustion. When the combustion load such as heating changed, the blower and fuel pump were adjusted to increase or decrease the amount of combustion. However, since the area of the flame opening of the combustion tube is constant, when the amount of combustion exceeds a certain level, the flame lifts, producing unburned gas and CO9 odor, and when the amount of combustion falls below a certain level, the flame surface becomes pale. Since the temperature at the center did not become high enough, the flame front partially disappeared, producing unburned gas, CO, and odor. In addition, when the ratio of fuel and air changed, in addition to unburned gas and CO9 odor, the flame approached the burner and the burner overheated, causing deformation. Therefore, the variable range of combustion amount that can maintain good combustion is limited.

OBJECTS OF THE INVENTION It is an object of the present invention to widen the variable range of combustion amount by keeping the flame port load constant.

Structure of the Invention The present invention provides independent passages from the carburetor to a plurality of combustion sections, and provides means for opening and closing these passages.
The flame is stabilized by changing the flame port area according to the increase/decrease in the amount of combustion and keeping the flame port load constant.

Description of examples Hereinafter, an explanation will be given based on one embodiment of the present invention.

In the figure, a heater 2 is embedded in the circumferential direction of the side surface of a bottomed vaporizer 1, and a mixing plate 3 having a diaphragm shape is attached to the open surface. Further, a blower 5 is provided on the side wall of the carburetor 1 via a blower passage 4, and a fuel thin tube 6 whose tip forms a nozzle is made to face the carburetor 1 through the blower passage 4, and the other end of this fuel thin tube 6 is made to face the carburetor 1 through the blower passage 4. is connected to a fuel tank 8 via a fuel pump 7. In the upper part of the vaporizer 1, along the circumferential direction, there is a rectifying cylinder 10 formed into a cylindrical shape and having a large number of pores 9, and a wire mesh provided around the rectifying cylinder 10 with a rectifying space 11 interposed therebetween. A combustion section 13 consisting of 12 is provided, and the upper end of this combustion section 13 is closed by a closing plate 14. An outer cylinder 16 is provided around the combustion section 13 via a combustion space 15 whose one end is closed by a closing plate 14. A passageway for flowing to the outside is formed by a spout 18 provided in the. The combustion section 13 is connected to the rectifier tube 1 by a partition plate 19.
0, a rectifying space 11 and a wire mesh 12 are partitioned, and an opening 20 is provided in the center of the partition plate 19, and a valve 22 connected to a valve shaft 21 is movably provided opposite to this opening 20. The other end of the valve stem 21 is inserted into the solenoid 23. This valve 22 is provided in a passage leading from the carburetor 1 to the combustion section 13, and opens and closes this passage.

Next, the operation will be explained. By energizing the heater 2 in the vaporizer 1, the heating temperature of the vaporizer 1 is increased. Thereafter, combustion air is introduced into the carburetor 1 by driving the blower 5 provided through the blower passage 4 . Subsequently, the fuel pump 7 is driven to draw fuel from the fuel tank 8, and the fuel is injected into the carburetor 1 from the nozzle at the tip of the fuel tube 6. The ejected fuel becomes granular and collides with the wall of the vaporizer 1, receives heat from the high-temperature wall and becomes vaporized gas, which passes through the constricted portion of the mixing plate 3 disposed above and flows to the combustion section 13. At this time, the vaporized fuel gas is mixed with combustion air, flows outward from the periphery of the combustion section 13 arranged with a wire mesh as a premixture, and is fired into the igniter in the combustion space 15 between the outer cylinder 16 and the combustion section 130. (not shown) to form a combustion flame on the surface of the wire mesh 12.

The valve shaft 21 moves up and down by turning the solenoid 23 ON and OFF, and the opening 2o is opened and closed by the valve 22 attached to the valve shaft 21. The combustion section 13 is separated into two parts by a partition plate 19, and has a plurality of passages leading from the vaporizer 1 to the wire mesh 12 and a plurality of flame ports of the wire mesh 12. By opening and closing the opening 20 with the valve 22, the fuel gas supplied to one of the wire meshes 12 can be shut off. That is, when the combustion amount is large, the solenoid 23 is turned off, the valve 22 is lowered, and the aperture 20 is communicated. A fuel pump 7 and a blower 5 supply fuel and air according to the amount of combustion.
A part of the vaporized fuel gas is supplied to the combustion section 13.
The other one flows out from the lower part of the screen, and the other part burns through the openings 20 over the entire area of the upper screen 12. When the combustion amount is small, it flows out from the upper part of the combustion section 13 and turns on the gold solenoid 23 of the combustion section 13.
Then, the valve 22 rises and closes the aperture 20. The fuel gas is vaporized by being supplied with fuel and air according to the amount of combustion, and the aperture 20 is closed.
Since it is blocked, it does not flow to the upper part of the combustion part 13, but flows out from the wire mesh 12 from the lower straightening tube 10. So ,.

Therefore, the flame is formed only in the lower part of the combustion section 13.

,゛ Therefore, when the amount of combustion is large, the wire mesh 12 is used.

The area of the flame opening is large, and when the amount of combustion is small, the area of the flame opening becomes small. That is, the flame port load becomes a constant value, and the outflow velocity corresponding to the combustion speed becomes a constant value. Therefore, since the flame outflow speed is fast, lifting does not occur, and because the outflow speed is slow, flame pulsation,
There is no backing up, quenching due to thinning, etc., and the area of the flame port can be set to be strong or weak depending on the amount of combustion, so there is tolerance for changes in the fuel-air ratio, and unburnt gas and odor can be reduced. There is no burning or red-hot flame.

By changing the ratio of the upper and lower parts of the combustion section 13 separated by the partition plate 19, the amount of combustion can be significantly reduced while maintaining good combustion. For example, if the ratio of the top and bottom of the combustion section 13 is 3:1, the large combustion zone will be 4,000K.
When set to cal/h, even if the small combustion amount with the valve 20 closed is set to i, 0OOKcalA, the mouth load is the same value, the flame formed on the wire mesh is the same, and the TDR is significantly reduced to 1/4. The amount of combustion can be varied. Therefore, by simultaneously interlocking the fuel pump 7 that supplies fuel, the blower 5, and the solenoid 23, effective combustion can be maintained even when switching the combustion amount.

Effects of the Invention By providing means for opening and closing the passages leading from the vaporizer to the plurality of combustion sections, the present invention can maintain stable combustion without causing a change in the flame outlet load even when the combustion amount is varied. As a result, the amount of combustion can be greatly reduced, making it possible to achieve comfort and energy savings.Since the burner port load can be set for each large and small amount of combustion, stable combustion can be obtained, and therefore the burner port load can be set small. This makes it possible to lower the flame temperature and reduce NOx.

[Brief explanation of the drawing]

The figure is a sectional view showing one embodiment of the present invention. 1... vaporizer, 2... heater, 5
...Blower, 7...Fuel pump, 13
... Combustion section, 19 ... Partition plate, 20.
...Opening hole (passage), 22...Valve (means for opening and closing), 23...Solenoid.

Claims (1)

Scope of Claims: (1) A means for supplying liquid fuel and air is connected to a vaporizer having a heating means, and a passage is provided from the vaporizer to a plurality of combustion sections, and in this passage, A liquid fuel combustion device provided with means for opening and closing this passage. (9) The liquid fuel combustion device according to claim 1, wherein means for opening and closing the passage and means for supplying liquid fuel and air are linked.