JPH0411965A - Controlling method for ultrasonic wave atomizer - Google Patents

Abstract

PURPOSE:To control vibration of the vibration member by equipping the ultrasonic wave vibration member, an ultrasonic wave generating means and a liquid supply valve, a liquid heating means and a temp. detecting means. CONSTITUTION:An atomizer 11 has a supporting member 24 to which an ultrasonic wave vibration member 10, a vibration member engaging hole 21, a liquid supply valve engaging hole 22 and a liquid supply path 23 are formed. Liquid supplied from a liquid supply valve 9 is heated by a glow plug 30 and atomized into fine droplets in the atomization part 12 of the ultrasonic wave vibration member 10. Further an amplitude setting circuit 3 reads-in the optimum amplitude value stored in an optimum amplitude value memory means 4 on the basis of the signals of a temp. sensor 31 and a flow rate sensor 1 and outputs the optimum amplitude value to a high-frequency oscillation circuit 5. Thereby ultrasonic wave vibration is imparted by amplitude correspondent to the amount of atomization treatment and atomization characteristics are made to optimum performance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention generally relates to a liquid substance such as a liquid fuel that is supplied (in this specification, liquid substance refers to a liquid such as a liquid fuel, or Regarding the control method of an ultrasonic atomization device for atomizing liquids (including liquid substances such as turbid solutions) using ultrasonic vibration, in particular, (a) automobiles, outboard motors, portable (b) Fuel injection nozzles for gas turbines, (c) Boilers, heating furnaces, and heating burners for industrial, commercial, and domestic use; ) Industrial liquid sprayers, such as drying sprayers for drying liquid materials such as food, pharmaceuticals, agricultural chemicals, fertilizers, etc., temperature and humidity control sprays, baked powder sprayers (ceramic granulation), spray coating equipment, reaction The present invention relates to an accelerator, and (e) a method for controlling an ultrasonic atomizer suitable for use in non-industrial liquid atomizers, such as pesticide sprayers, disinfectant sprayers, etc.

[Prior Art] An ultrasonic atomizer is driven by an ultrasonic vibration generating means such as an electric/acoustic transducer or a high frequency oscillator,
The device is equipped with an ultrasonic vibrator horn that atomizes the supplied liquid substance, and when atomizing the liquid substance, the ultrasonic vibrator horn adjusts the size of the spray flow rate, the size of the droplets, etc. The quality of the atomization characteristics of the ultrasonic atomization device has various effects on the performance of equipment and equipment in which the ultrasonic atomization device is used. For example, in a combustion device, if the atomization characteristics of the ultrasonic vibrator horn are poor, accurate air-fuel ratio control may not be possible, or the combustion state may deteriorate, causing hydrocarbons and carbon monoxide contained in the exhaust gas to be removed. This results in problems such as an increase in the amount of soot and an increase in the amount of soot.

In order to solve this problem, as shown in Japanese Patent Publication No. 52-8935 and Japanese Patent Publication No. 59-38107, the cross-sectional shape of the ultrasonic transducer horn along the axis is expanded toward the tip. An ultrasonic transducer horn with improved atomization characteristics is known. Furthermore, as shown in Japanese Patent Application Laid-Open No. 64-851f35, the present inventors formed a hollow part in the large diameter part of the enlarged diameter vibrator horn, thereby eliminating the need to increase the size of the ultrasonic vibration generating means. We have proposed a method that can be driven with high amplitude without reducing the amplitude, and can also reduce the particle size of atomized droplets without restrictions on the atomization area, increasing the maximum amount of atomization. ing.

[Problems to be Solved by the Invention] By the way, when a liquid is atomized by ultrasonic vibration, generally speaking, the higher the temperature of the liquid and the smaller the amplitude, the more droplets are atomized. It is known that the grain size can be made finer.

However, when the inventors conducted experiments, the second
As shown by line B in the figure, it was found that as the fuel temperature increases, the average particle size decreases, but when the fuel temperature reaches a predetermined value of 11 or higher, the average particle size conversely increases.

Furthermore, as shown in Figure 3, when the amplitude of ultrasonic vibration is small, the average particle size of the atomized droplets is smaller than when the amplitude is large, but on the other hand, the amount of atomized liquid is small. It has been found that if the processing amount is increased with a small amplitude, the processing limit will be reached at point A in the figure and atomization will become impossible.

The present invention solves the above-mentioned problems by applying ultrasonic vibrations at an optimal amplitude commensurate with the amount of spray to be processed, and making it possible to achieve the best performance in atomization characteristics from small to large spray volumes. The present invention aims to provide a method for controlling an ultrasonic atomization device.

The present invention solves the above problems by increasing the amount of spray treatment by heating the liquid, and applying ultrasonic vibration with an optimal amplitude commensurate with the amount of spray treatment.
It is an object of the present invention to provide a method of controlling an ultrasonic atomizer that can optimize atomization characteristics.

[Means for Solving the Problems] For this purpose, the method for controlling an ultrasonic atomization device of the present invention includes: an ultrasonic vibrating member 10; an ultrasonic generator 13 for applying ultrasonic vibration to the ultrasonic vibrating member 10; , a liquid supply valve that supplies liquid to the atomization section 12 of the ultrasonic vibration member 10;
It is characterized by comprising a liquid heating means 30 that heats the liquid and a temperature detection means 31 that detects the temperature of the liquid, and reduces the amplitude of the ultrasonic vibration member 10 when the temperature of the liquid is equal to or higher than a predetermined value. shall be.

Note that the numbers added to the above configurations are for comparison with the drawings, and the configurations of the present invention are not limited thereby.

[Function] In the present invention, as shown in Fig. 2, the average particle size becomes smaller as the fuel temperature increases, but if the fuel temperature reaches a predetermined value of 11 or more while the amplitude remains unchanged, the average particle size becomes smaller as shown in line B. Since the average particle size increases when the fuel temperature reaches a predetermined value of 11 or higher, by reducing the amplitude, the average particle size can be reduced as shown by line C.

[Example code] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a sectional view showing one embodiment of the ultrasonic atomization device used in the present invention.

The ultrasonic atomization device 11 includes an ultrasonic vibration member 10, a vibration member fitting hole 21, a liquid supply valve fitting hole 22, and a liquid supply path 2.
It has a support member 24 having a number 3 formed thereon. An atomizing section 12 is formed at one end of the ultrasonic vibration member 10, and an electric/acoustic conversion element 13 is provided at the other end. Note that the shape of the atomizing portion 12 may be a well-known shape such as a round shape or a bat shape.

An outer cylinder 25 is fitted into the vibration member fitting hole 21, and an inner cylinder 26 is further screwed onto the inner periphery of the outer cylinder 25.
6, an annular liquid passage 27 is formed therebetween. The ultrasonic vibration member 10 is fixed to the inner circumference of the outer cylinder 25 by a fixing member 29 via an O-ring 28.

The liquid supply valve fitting hole 22 communicates with the annular liquid passage 27 via the liquid supply path 23, and supplies liquid from the tip of the annular liquid passage 27 to the atomizing section 12 of the ultrasonic vibrating member 10. There is. A glow plug 30 for heating the liquid and a temperature sensor 31 are arranged within the liquid supply path 23 .

In the ultrasonic atomizer 11 having the above configuration, the liquid supplied from the liquid supply valve 9 is heated by the glow plug 30 and atomized into fine droplets in the atomization section 12 of the ultrasonic vibrating member 10. .

Next, one embodiment of the control method of the present invention will be described with reference to FIGS. 1 to 3.

In FIG. 1, 10.31 is the ultrasonic vibration member and the temperature sensor, 1 is a flow rate sensor that detects the amount of liquid supplied;
2 is an electronic control device, 3 is an amplitude setting circuit, 4 is an optimum amplitude value storage means, and 5 is a high frequency oscillation circuit. The amplitude setting circuit 3 reads the optimum amplitude value stored in the optimum amplitude value storage means 4 based on the signals detected by the temperature sensor 31 and the flow rate sensor 1, and outputs it to the high frequency oscillation circuit 5. It is.

Figure 2 shows the relationship between fuel temperature and average particle size when kerosene is supplied as a liquid to the ultrasonic atomizer shown in Figure 4. Line B shows the case where the amplitude is 20 μrrh, and line C shows the case where the amplitude is 10 μm. show.

As shown in the figure, as the fuel temperature increases, the average particle size decreases, but the amplitude remains the same and the fuel temperature remains at the predetermined value T1.
If the temperature exceeds this value, the average particle size will increase as shown in line B. Therefore, when the fuel temperature exceeds the predetermined value T1, it is possible to reduce the average particle size as shown in line C by reducing the amplitude. can. This predetermined temperature TI and amplitude value are stored in the optimum amplitude value storage means 4, and the temperature sensor 3
When the fuel temperature detected by 1 becomes equal to or higher than a predetermined value, the amplitude is controlled to be lowered.

FIG. 3 shows the relationship between the optimum amplitude value WB and the spray processing amount Q. When the amplitude is lowered using the method shown in FIG. 2, if the throughput is increased, the processing limit is reached at point A in the diagram, and atomization becomes impossible. Therefore, the spray processing amount Q is Q11Q2, Q3
By increasing the optimum amplitude value WB from 18 μm to 20, 22, and 24 μm, respectively, the optimum amplitude value WB is set such that the minimum particle size can be obtained according to the change in the spray throughput Q. I'll do what I do. This relationship is then stored in the optimum amplitude value storage means 4 as a table or map.

In addition, in the above embodiment, the optimum amplitude value WB is changed stepwise according to the change in the spray throughput Q, but the optimum amplitude value WB is changed continuously according to the change in the spray throughput Q. You can do it like this.

[Effects of the Invention] As described above, according to the present invention, the amount of atomization can be increased by heating the liquid, and the atomization characteristics can be improved by applying ultrasonic vibration with an optimum amplitude commensurate with the amount of atomization. can achieve the best performance.

Furthermore, since the optimum amplitude value is set according to the processing amount, it is expected that the power loss of the ultrasonic vibrating member will be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the method of controlling an ultrasonic atomizer of the present invention, FIGS. 2 and 3 are diagrams showing atomization characteristics for explaining the control method, and FIG. 1 is a sectional view showing one embodiment of an ultrasonic atomization device used in the present invention. DESCRIPTION OF SYMBOLS 1... Flow rate detection means, 3... Amplitude setting circuit, 4 river optimum amplitude value storage means,... Ultrasonic atomization device, 10... Ultrasonic vibration member, 12... Atomization part, 13...Ultrasonic generation means, 30...Liquid heating means, 1...Temperature detection means. applicant

Claims (2)

[Claims] (1) An ultrasonic vibrating member, an ultrasonic generating means for applying ultrasonic vibration to the ultrasonic vibrating member, a liquid supply valve that supplies liquid to the atomization section of the ultrasonic vibrating member, and heating the liquid. an ultrasonic atomizer comprising: a liquid heating means for detecting the temperature of the liquid; and a temperature detecting means for detecting the temperature of the liquid, the apparatus reducing the amplitude of the ultrasonic vibrating member when the temperature of the liquid is equal to or higher than a predetermined value. control method. (2) A flow rate detection means for detecting the spray processing amount, and applying ultrasonic vibration to the ultrasonic vibration member using an optimum amplitude value that changes the amplitude according to the change in the spray processing amount and obtains the minimum particle size. The method for controlling an ultrasonic atomizer according to claim 1, characterized in that: