JPS6249108A - Supersonic wave combustion device - Google Patents

Abstract

PURPOSE:To promote a mixing of fuel with air and provide a stable and superior combustion having a stable flame shape by a method wherein an assist air supplying means is provided and the assist air with a proper given kinetic energy is blown into a group of mist drips. CONSTITUTION:A vibrator element 1 is continuously vibrated with a supersonic wave vibration generating means 100 connected to a main body 1a. Thus, when the liquid fuel is supplied to an edge part 1 through a supplying valve and a supplying passage 4 via a pipe line, the liquid fuel is turned into fine particles and injected outwardly. In this case, a part of the combustion air is introduced into the space S through an inlet 20 as an assist air. Then, the air is supplied to the combustion area after being injected from the outlet 21. A sectional area of the assist air passage 22 and a flow rate of assist air are adjusted in such a way that a desired aassist air injection speed can be attained. A flow of the assist air adds a proper kinetic energy to the injected drips struck against the injected drips injected from the edge part 2 of the vibrator element 2, promotes mixing with the combustion air flowing around the part and improves the combustion state. As a result, it is possible to improve an efficiency of combustion, and reduce an emission of the discharged materials such as soot or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic combustion device, and more particularly to an ultrasonic combustion device that uses an ultrasonic vibrator having an edge portion H at one end on the combustion chamber side. 1) Gas turbine injection nozzle (2) An ultrasonic combustion device suitably applied as a burner for industrial, commercial, and domestic boilers, heating furnaces, and heaters.

BACKGROUND OF THE INVENTION Pressure atomization burners or liquid atomizers have traditionally been used to atomize, or atomize, liquid fuels for the various combustion devices mentioned above. In addition, various injection nozzles using ultrasonic waves have been tried and widely used in place of such pressure spray burners or liquid sprayers.

The present applicants have proposed an ultrasonic injection nozzle that improves various drawbacks of the injection nozzle used in the conventional spray burner or liquid atomizer, and the conventional ultrasonic injection nozzle (Japanese Patent Application No. 59-77572). (see ). This ultrasonic jet nozzle has an ultrasonic vibration generating means connected to one end, and an elongated vibrator with an edge portion fixed to the other end of the nozzle housing, and liquid is supplied to the edge portion of the vibrator. This is an ultrasonic jet nozzle designed to atomize liquid.

This ultrasonic jet nozzle achieves a large capacity, which was previously considered impossible, by adopting a novel structure called a vibrator with an edge. Although the present invention relates to an ultrasonic combustion device using this ultrasonic injection nozzle, there have been no reports of this type of use in the past.

Problems to be Solved by the Invention The ultrasonic jet nozzle proposed by the above applicants has made it possible to increase the capacity, which was considered impossible in the past, but the biggest drawback is that the jetting speed of liquid particles is slow. .

Therefore, when used as a combustion device, the ejection speed of the atomized fuel is low, so there is a tendency for the atomized fuel to be insufficiently mixed with combustion air. The present invention relates to a combustion device in which the mixing characteristics of atomized fuel and combustion air are improved in the ultrasonic combustion device using the ultrasonic injection nozzle according to the prior invention.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an ultrasonic combustion device with improved mixing characteristics of atomized fuel and combustion air. Another object of the present invention is to provide an ultrasonic combustion device that can prevent fuel from dripping from the vicinity of the vibrator.

Means for Solving the Problems The above-mentioned aspects are achieved by the ultrasonic combustion device according to the present invention. To summarize, the present invention provides an ultrasonic combustion device for burning liquid, in which a housing is provided with an elongated vibrator connected to an ultrasonic vibration generating means at one end and having a liquid fuel atomization spray section at the other end. The ultrasonic combustion device is characterized in that a part of combustion air is introduced into a gap formed between the housing and the vibrator, and is discharged from a tip opening. Next, the ultrasonic combustion device according to the present invention will be explained in more detail with reference to the drawings. As described above, the present invention can be suitably used in combustion devices for various purposes, but in this application, the embodiment of the injection nozzle for a gas turbine shown in FIG. 1 will be described in detail. In FIG. 1, the injection nozzle 10 includes an elongated, generally cylindrical housing 8. The housing 8 is coaxially formed with aligned center holes 6a and 6b.

The vibrator 1 is placed in the center holes 6a and 6b. As can be seen from FIG. 1, the center hole 6a has a larger diameter than the center hole 6b and is formed to surround most of the vibrator 1, and there is no space between the vibrator 1 and the center hole 6a. S is formed. The vibrator 1 has an upper main body portion 1a, and the main body portion 1a.
Vibrator shaft portion 1b and main body portion 1a in the form of an elongated column with a smaller diameter
It has a transition part 1c that connects the shaft part 1b and the shaft part 1b. Main body part 1
A is provided with a flange 1d having a larger diameter, and the flange 1d is attached to a shoulder 12 formed at the upper end of the housing 8 and to the upper end surface of the housing 8 by bolts (not shown). It is attached to the housing 8 by an annular vibrator holder 14. At the tip of the vibrator 1, that is, at the tip of the shaft portion 1b, an injection portion, that is, an edge portion 2 whose dimensions and shape will be described in detail later is formed. Further, below the housing 8 is a supply passage 4 for supplying fuel to the edge portion 2.
One or more ships will be formed. The fuel supply hole 16 of the supply passage 4 is connected from a fuel supply source (not shown) to an external supply pipe (
Liquid fuel is supplied through the fuel tank (not shown). The flow rate and supply/stop of fuel are controlled by a supply valve (not shown) provided in the external supply pipe.

In the above configuration, the vibrator 1 is continuously vibrated by the ultrasonic vibration generating means 100 connected to the main body portion 1a. Therefore, when the liquid fuel is supplied to the edge portion 2 via the pipe, the supply valve and the supply passage 4, the liquid fuel is atomized and injected outward. As shown in FIG. 1, the edge portion 2 of the vibrator 1 is shaped like an annular step consisting of five steps whose diameter is gradually reduced. It may be stepped or may have any other shape. According to the present invention, the housing 8 is provided with an assist air inlet 20, and an assist air passage 22 is formed between the housing 8 and the tip of the vibrator shaft portion 1b.
The outlet becomes the assist air outlet 21. A part of the combustion air is introduced into the space S from the population 20 as assist air, and after being ejected from the outlet 21 is supplied to the combustion zone. The cross-sectional area of the assist air passage 22 and the assist air flow rate are adjusted to obtain a desired assist air jetting speed. The flow of assist air adds appropriate kinetic energy to the spray droplets that collide with the spray droplets ejected from the vibrator edge portion 2, promoting mixing with the surrounding combustion air and improving the combustion state. As a result, it is possible to improve combustion efficiency and reduce soot and other exhaust emissions. Furthermore, when the ultrasonic injection nozzle is used in a horizontal position, a pool of liquid generated at the tip of the vibrator may drip from near the tip of the vibrator due to its own gravity, causing so-called fuel dripping and becoming unstable. This may result in insufficient combustion or the formation of coke-like substances. This problem can be solved by flowing assist air to suppress the growth of an excessively large liquid pool, thereby almost eliminating the accumulation of coke-like substances.

The specific conditions and dimensions of the ultrasonic combustion device according to the present invention described above are as follows.

Output of ultrasonic generating means: 10W Vibrator amplitude = 34μm Frequency +33KHz Vibrator shape and dimensions (Example shown in Figure 1) Edge part 1 stage: Diameter near mm 2 stages ・Diameter: 5 mm 3 stages: Diameter: 5 mm 4 stages ・Diameter: 4mm 5 stages ・Diameter 3mm Height of each stage +2mm Assist air passage width: 1.0IIlfD fuel t-
1 oil type Kerosene flow rate: 10cm3/sec Injection pressure: 5kg/eG Temperature: Room temperature Vibrator material: Titanium With this configuration, the flame shape is comparable to that of a normal T-collection forced draft burner. It was possible to obtain stable and good combustion.

As described in detail of the invention, by including an assist air supply means and blowing assist air given appropriate kinetic energy into the spray droplets, the mixing of fuel and air is promoted, resulting in a flame shape. It became possible to obtain stable and good combustion.

This makes it possible to provide an ultrasonic combustion device with improved combustion efficiency and reduced exhaust emissions such as soot.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of an ultrasonic combustion device according to the present invention. 1, : Vibrator 2, : Edge part 4, : Liquid supply passage 10, - Injection nozzle 20, - Assist air inlet 21, , Assist air outlet 22, Near assist air passage 100, : Ultrasonic vibration generating means Applicant: Toa Fuel Industry Co., Ltd. Agent Patent Attorney Kohei Kubota Figure 1], 1) Road 2 Eno/': Ko

Claims (1)

[Claims] In an ultrasonic combustion device for burning liquid, the housing is provided with an elongated vibrator connected to an ultrasonic vibration generating means at one end and having a liquid fuel atomization injection section at the other end,
An ultrasonic combustion device characterized in that a part of combustion air is introduced into a gap formed between the housing and the vibrator, and is discharged from a tip opening.