JPS5945427B2 - ultrasonic spray device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION There are two types of atomizers using ultrasonic waves: a resonance type and an electrical vibration type, and the present invention relates to an improvement of the latter type.

Ultrasonic vibrations caused by electrical vibrations are mainly produced by magnetostrictive vibrators,
Alternatively, it can be obtained by using an electrostrictive vibrator, to which a sprayer is attached via a suitable horn to atomize the fluid to be sprayed.

This method is 15KH! Although it has been put into practical use in the range of Z to several ■■, it can only be used for spraying at minute flow rates. Since the resonance type uses an airflow atomization method, it is possible to atomize a large amount of particles, but the most commonly used method is a pressure atomizer, which applies pressure to the atomized fluid itself and sprays it from pores. It is. In particular, a spiral pressure atomizer is typical. In general, fuel injection combustion equipment requires low noise and low pollution combustion, and the factor that governs this combustion mechanism is the spray characteristics.

In other words, these factors include a spray group with uniform particle size, appropriate penetration power (horizontal flight distance), and an average particle size value found in the equipment. The above-mentioned ultrasonic atomizer can change the average particle size by changing the vibration amplitude value by changing the electrical input when supplying the same fuel flow rate.

Therefore, even if the flow rate changes, it is possible to maintain the same average particle size, but it has the disadvantage that atomization is possible only in small volumes. In addition, with the spiral pressure sprayer, a swirling liquid film is formed by applying sufficient pressure to the fluid to be atomized to atomize the atomization, so it is easy to obtain a spray group with a large penetrating force, and a large volume of fluid can be produced. Atomization is possible.
However, there is a relationship between flow rate and pressure: flow rate (Ix'J pressure), and as the pressure changes, the flow rate changes and the average particle size also changes significantly. It is an object of the present invention to provide an ultrasonic spraying device that overcomes these disadvantages and can make the average particle size uniform and obtain a very small average particle size.

That is, the present invention imparts longitudinal vibration to the swirling liquid film formed by the swirling flow by inputting an electrical signal, thereby making it possible to atomize a large volume of fluid, which was impossible with conventional electrically vibrating ultrasonic atomizers. It is possible to maintain atomization characteristics when the flow rate (or pressure) of the fluid to be sprayed changes, which was impossible with pressure atomizers, and it also maintains atomization characteristics at low pressure, which was the biggest drawback of pressure atomizers. The feature is that it also allows for improvements. Embodiments of the invention are described below with reference to the drawings. In FIG. 1, 1 is an oscillator, 2 is an electric vibrator such as electrostrictive, magnetostrictive, crystal, etc., and an emitted current is sent from the oscillator 1 through a conductor 11. 3 is a stem, taper or exponential type horn for transmitting ultrasonic waves, which extends vertically and is attached to the spray nozzle tip 6 which is fixed (by silver soldering, argon welding, beam welding or screw connection) at the lower end. It has a vertical hole 5 forming a flow path for sending the atomized liquid, and a pressure flow pipe 4 through which the liquid to be atomized is guided from a liquid source S by a pump P communicates with the vertical hole flow path 5.

The liquid in the vertical hole channel 5 flows onto the bottom wall 31 of the horn 3 as shown in FIGS.
As shown in the figure, a suitable number of liquid outflow pores 30 bored on the same circumference allow the liquid to be led out downward. The spray nozzle tip 6 forms the liquid flow led out from the pore 30 into a hanging rod-like liquid film, as shown in FIGS. 2 and 4, for example.
It is configured as shown in the figure. That is, an annular groove 7 that coincides with the same circumference of the pore 30 of the horn 3 is provided on the upper surface of the disc-shaped body fixed to the lower end of the horn 3, and a spiral chamber with an inverted conical inner surface is formed in the center. 9 (4 in Figure 4)
As shown in FIG.
It is provided tangentially to the upper edge of the swirl chamber 9. As a result, swirling energy is given to the liquid flow introduced from the annular groove 7 into the swirl chamber 9, and the liquid flow is ejected from the external nozzle hole 10 provided at the lower end of the swirl chamber. A thin liquid film is formed in the shape of a hanging rod, and then the particles are gradually atomized. At this point, due to the longitudinal vibration caused by the ultrasonic waves applied to the nozzle tip 6 by the vibrator 2 and the horn 3, the liquid is forcibly removed. There is a rapid transition from membrane to wavy flow and then to atomization.
If the pressure of the liquid to be sprayed is greater than the pressure at which a swirling liquid film is formed in the liquid stream ejected from the nozzle hole 10, the purpose of atomization by ultrasonic vibration can be achieved, and the required average particle size, particle size distribution, Pressure shall be applied depending on the spray angle. The same applies to non-Newtonian fluids. The electric input can change the atomization characteristics by several watts. The effects of the present invention are as follows. 1. A large volume of fluid can be atomized.

It is possible to control the penetration power of the two spray groups.

3. Atomization characteristics (average particle size, particle size distribution) can be controlled when supplying the same flow rate.

4 Atomization characteristics can be maintained even if the flow rate changes.

5. Superior atomization characteristics than a spiral pressure atomizer can be obtained even at low pressure.

6 Low-noise combustion is possible due to appropriate penetration force and uniform granulation.

Low NO combustion is possible because it is easy to form a 7-layer mixture.

8 Applicable to nozzle tips with a wide range of flow coefficients (C+0.1 to 0.85).

9 It is possible to atomize not only Newtonian fluids but also non-Newtonian fluids.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view showing the ultrasonic spraying device of the present invention;
FIG. 2 is an enlarged sectional view of the spray tip portion, and FIGS. 3 and 4 are cross-sectional plan views taken along the - line and - line of FIG. 2 (FIG. 1). 1... Transmitter, 2... Vibrator.

Claims (1)

[Claims] 1 An ultrasonic vibrator 2 that is energized by a transmitter 1 to vibrate, and a flow path 5 that is integrally fixed to this ultrasonic vibrator 2 and communicates with a pressure flow tube 4 that guides the liquid to be atomized from a liquid source. and a nozzle tip 6 that is integrally fixed to the tip of the ultrasonic conduction horn 3 and ejects the liquid to be atomized from the flow path 5. The nozzle tip 6 is provided with a large number of pores 30 connected to the flow path 5, and the nozzle tip 6 is provided with a conical swirl chamber 9 in its center that communicates with the nozzle hole 10 at the tip. The pore 3 of the ultrasonic conduction horn 3 is formed by a plurality of guide grooves 8 provided tangentially from the base end periphery and an annular groove 7 communicating therewith.
1. An ultrasonic spraying device characterized by communicating with zero.