JPS6384664A - Cooled ultrasonic atomizer - Google Patents

Abstract

PURPOSE:To carry out stabilized atomization with a large capacity even under high temp. conditions by forming a supply liq. passage to surround the ultrasonic vibration generating means of a vibrator, and cooling the ultrasonic vibration generating means with the supply liq. circulating in the passage. CONSTITUTION:The long and slender vibrator 1 with one end connected to the ultrasonic vibration generating means and having a liq. atomization nozzle 1C is provided, and the liq. is atomized. The supply liq. passage 16 is provided to surround at least the ultrasonic vibration generating means 100 of the vibrator 1. At least the ultrasonic vibration generating means 100 is cooled by the supply liq. circulating in the passage 16. As a result, stabilized atomization can be carried out with a large capacity even under high temp. conditions, the atomization condition (flow rate and particle diameter) is not changed with the properties, especially viscosity, of the supply liq., and stabilized atomization can be performed.

Description

[Detailed Description of the Invention] Production! The present invention generally relates to ultrasonic defrosting devices, and in particular to (1) automotive injection valves, such as electronically controlled gasoline injection valves or electronically controlled diesel injection valves, and (2) gas turbine fuels. Nozzle, (3) Suitable for use in industrial, commercial, and domestic boilers, heating furnaces, heater burners, etc.
The present invention relates to an ultrasonic atomization device that atomizes liquid intermittently or continuously.

BACKGROUND OF THE INVENTION Conventional pressure atomizing burners have been used in the past to atomize or atomize liquids, such as liquid fuels, in various fields such as those mentioned above. Ultrasonic spray nozzles, ie, ultrasonic atomizers, are widely used in place of such atomizing burners.

The present applicant has proposed an ultrasonic atomizer that improves the various drawbacks of the injection nozzle used in the conventional injection A burner and the conventional TFL sonic injection nozzle (Japanese Patent Application No. 1986-7).
(Refer to No. 7572), this ultrasonic A and other devices have a sweat wave! ! 11 a long and narrow vibrator (horn) connected to the generating means and having an edge portion (atomization portion) at the other end;
This is an ultrasonic jet nozzle which is fixed to a nozzle housing, supplies liquid to the edge portion of the vibrator, and atomizes the liquid.

The ultrasonic jet nozzle according to the present applicant described above is
It is possible to atomize a liquid intermittently or continuously, and it can be used very suitably for the above-mentioned product applications.

However, when such an injection nozzle is used in a general combustor such as a boiler, especially a gas turbine,
The temperature of the injection nozzle rises due to high temperature due to heating from the combustor inlet or heat generation due to vibration of the vibrator itself, and the vibration state fluctuates, causing the injection Artk to change, or sometimes no spray at all. was there.

The present inventors conducted research on the properties of such an ultrasonic jet nozzle, and found that when such an M1 sonic jet nozzle ("A atomization device") is used, it is usually used especially as a vibrating element of an ultrasonic generating means. PZT (zircon lead titanate)
discovered that when heated, it undergoes overheating destruction and ceases to generate effective ultrasonic vibrations. In other words, if the heat of the vibrating element exceeds the Curie point (approximately 350°C), it will no longer exhibit piezoelectric phenomena, and furthermore, in the case of a bolted Langevin vibrating element, the vibration element will be in contact with the vibrating element. Because there is a difference in linear expansion coefficient between the vibrating element and the metal, stress is generated at the contact surface between the vibrating element and the metal due to the heat generated by the vibrating element, causing physical damage such as cracks in the vibrating element. It was found that effective ultrasonic vibrations were no longer generated.

Furthermore, even at temperatures below γ, when PZT is heated above, for example, 60°C, its aerodynamic properties change slowly but irreversibly, and their accumulation can affect ultrasonic vibrations. Do you get it.

The present invention is based on this new knowledge and relates to an improvement of the ultrasonic atomization device according to the prior invention.

Forethought 1 An object of the present invention is to provide an ultrasonic atomization device that can supply liquid intermittently or continuously and that can be effectively used at high temperatures.

Another object of the present invention is to supply a large volume of liquid and to stably spray a large amount of liquid, no matter how high the temperature is.
, I! The object of the present invention is to provide ultrasonic atomization 5t21 that can be sprayed.

Another object of the present invention is to provide an ultrasonic atomization device that can achieve stable atomization in which the state of atomization (flow rate 1 particle size) does not vary depending on the properties of the supplied liquid, particularly the viscosity.

For aging: The above aspects are achieved by the cooled ultrasonic injection device according to the present invention. To summarize, the present invention provides an ultrasonic atomization device for atomizing liquid, which includes an elongated vibrator connected to an ultrasonic vibration generating means at one end and having a liquid atomization injection section at the other end. , surrounding at least the ultrasonic vibration generating means of the vibrator to form a flow path for the supply liquid;
According to a preferred embodiment of the present invention, the ultrasonic atomizer is characterized in that at least the ultrasonic vibration generating means is cooled by the supply liquid undulating through the flow passage. is formed in a housing that surrounds the vibrator.

Practical Example Next, a cooling type ultrasonic atomizer according to the present invention will be explained in more detail with reference to the drawings.

The present invention can be used for injection for various purposes as described above. In this embodiment, the present invention will be described in relation to a fuel injection nozzle used in a combustor such as a gas turbine.

Referring to FIG. 1, a cooling type ultrasonic frosting device, in this embodiment a fuel injection nozzle 10 for a gas turbine, includes a nozzle housing 12 having an elongated, generally cylindrical shape. The housing 12 is formed with coaxial center holes 14a and 14b that are aligned. Center holes 14a and 14 of housing 12
A vibrator l is placed through b.

The vibrator l includes an upper main body part 1a, a vibrator shaft part 1b which is formed into a stepped shape in this embodiment but is shaped like an elongated column and has a diameter smaller than that of the building block body part 1a, and a tip end of the vibrator shaft part 1b. It has a liquid atomization section connected to the edge section 1c. Again 1
An ultrasonic vibration generating means 100 for applying Mii wave vibration to the vibrator 1 is connected to the other end of the main body 1a. The ultrasonic vibration generating means has a bolt-fastened Langivin vibration element 100a, and is supplied with a required current from, for example, a vibration feedback type transmission circuit (not shown) to generate ultrasonic vibrations to be transmitted to the vibrator.

As can be seen from FIG. 1, in this embodiment, the center hole L4a has a larger diameter than the hole 14b, and the main body 1m of the vibrator 1 and the ultrasonic wave generating means 100 are located in the center hole 14a. The vibrator 1 is arranged so that the shaft portion 1b of the vibrator 1 is located in the central hole 14b. The vibrator 1 is attached to the housing 12 by fixing the main body portion 1a of the vibrator 1 to the center hole 14a by means 2 which also serves as a sealing means.

An edge portion 1c formed at the tip of the vibrator 1, that is, the tip of the shaft portion 1b, is provided so as to be exposed outward from the center hole 14b. As shown in the figure, the edge portion 1c may be formed into a plurality of chevron-shaped steps with the same diameter, or may be formed into an annular step-like shape consisting of a plurality of steps whose diameter is gradually reduced. can be any other shape.

According to the present invention, the annular fuel supply passage 16 extends through the housing 12a in the axial direction in the upper housing 12a which defines the center hole 14a and surrounds the ultrasonic vibration generating means lOO. formed.

A fuel supply port 15 is provided at its upper end. Further, a fuel supply passage 18 is formed in the lower housing 12b surrounding the shaft portion 1b of the vibrator, passing through the housing 12b in the axial direction. One end 18a of the fuel supply passage 18 communicates with an annular fuel passage 16 formed in the upper housing 12a,
The other end 18b is open to the lower end surface of the lower housing 12b. One or more fuel passages 18 can also be formed.

It is also possible to provide an annular supply passage if necessary.

In the above configuration, liquid fuel is supplied to the fuel supply port 15 of the annular supply passage 16 from a fuel supply source (not shown) via an external supply pipe (not shown). The flow rate and supply/stop of fuel are controlled by a supply valve (not shown) provided in the external supply pipe.

To explain the operation of the atomization device according to the present invention, the vibrator 1 is continuously vibrated by the ultrasonic vibration generating means 100 operatively connected to the main body portion 1a. Therefore, when the liquid fuel is supplied to the edge portion 1C of the oscillator 1 via the conduit, the supply valve and the supply passage 16.18, the liquid fuel is atomized and injected outward.

According to the present invention, an annular fuel supply passage 16 is formed in at least the upper housing 12a, and the fuel supply passage 16
Since the liquid fuel is introduced into the combustor and flows, the fuel acts as a cooling medium for the upper housing 12a whose temperature has been raised by heating etc. from the combustor, and the upper housing 12a and the ultrasonic waves housed in the housing 12a are Of course, the upper housing 1 serves to prevent the temperature rise of the generating means 100.
2a and the lower housing 12b, heat is not transferred from the heated housings 12a and 12b to the vibrator 1, and the vibrator 1 itself, which has been heated or generates heat, is not transferred to the housing. It is cooled by the fuel flowing inside 12a and 12b.

By cooling at least the ultrasonic generating means 100 with the supplied fuel in this way, even if the injection nozzle lO is placed under a high temperature, the vibrating element 100a of the ultrasonic generating means and furthermore the vibrating element l will reach a high temperature that exceeds the allowable temperature. The sexual residue does not change due to thermal expansion or tissue changes.

In the injection nozzle 10, the supplied fuel is 1,
51/m f n, and the temperature at the inlet 15 is 2
When the temperature was set to 0°C, the temperature of the vibrator of the injection nozzle and the ultrasonic vibration generating means 100, which were installed at an ambient temperature of about too°C, could be maintained at 60°C or lower. As a result, the supply to the vibration element is 1! The vibration was stabilized without increasing the waterfall, and the spray amount was kept constant at all times.

i Mitate A] As explained below-1-, the ultrasonic atomizer according to the present invention equipped with a cooling means is capable of emitting a large volume of sharp and stable jet A even under high temperatures, and It is possible to provide an ultrasonic atomization device that can achieve stable atomization in which the state of atomization (flow rate, particle size) does not vary depending on the properties of the supplied liquid, particularly the viscosity.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of an ultrasonic atomization device according to the present invention. l: Vibrator IC: Liquid atomization injection part (edge part) 12a Upper housing 12b: Lower housing 15: Fuel supply port 16: Annular fuel supply passage 18: Fuel supply passage lOO: Itfl Sonic vibration generating means 100a: Vibration element Agent Patent Attorney Akira Kura Tachibana 2°1.・II
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Claims (1)

[Claims] 1) In an ultrasonic atomization device for atomizing liquid, an elongated vibrator is connected to an ultrasonic vibration generating means at one end and has a liquid atomization injection section at the other end. A supply liquid flow path is formed surrounding at least the ultrasonic vibration generation means of the vibrator, and at least the ultrasonic vibration generation means is cooled by the supply liquid flowing through the flow path. An ultrasonic atomization device featuring: 2) The device according to claim 1, wherein the supply liquid flow path is formed in a housing that surrounds the vibrator.