JPS5862411A - Atomizer - Google Patents

Abstract

PURPOSE:To obtain the device, constitution thereof is simple and compact and which stably generates a large amount of atomized particles with extremely small grain size, by intermittently driving an electric vibrator. CONSTITUTION:A vibrator driving section 53 is formed by a power supply section 55, a first oscillator 56 and an amplifier 57, and supplies alternating voltage to an electric vibrator 42. On the other hand, an intermittent control section 54 consists of a second oscillator 58 and a switch circuit 59 driven by the oscillator 58. The electric vibtator 42 is supplied with voltage obtained by amplifying the output voltage of the intermittent wave-form of the first oscillator 56 by means of the amplifier 57 because the output of the first oscillator 56 is interrupted by means of the switch circuit 59 turned ON/OFF by the output of the second oscillator 58. Accordingly, constitution is simplified and compacted, and atomized particles with uniform and extremely small grain size are generated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an atomization device for atomizing liquid fuel such as kerosene and light oil, water, and liquids such as chemical solutions. This relates to the atomization device used.

The first object is to provide an atomizing device which is simple in construction, compact and therefore extremely low cost. The second purpose is low power consumption and fine particles.

An object of the present invention is to provide an atomization device with excellent atomization characteristics.

Conventionally, various types of liquid atomization devices have been proposed, but among them, atomization devices that use ultrasonic waves are particularly
Atomizing devices as described below have been proposed. The first atomization device is an amplitude amplification type ultrasonic atomization device equipped with an amplitude amplification horn-shaped vibrator.

This is a Langevin type piezoelectric vibrator or a ferrite co3.
A magnetostrictive vibrator using a magnetostrictive vibrator is attached to a horn-type amplitude amplifier made of duralumin, etc., and the vibration amplitude of the vibrator is amplified, and the maximum amplitude part is connected to a liquid supply means such as a pump. is supplied and atomized. As is well known, the horn-type amplitude amplifier requires extremely high processing precision in order to guarantee mechanically stable vibration of the vibrator, and also requires high precision in mounting to the equipment. . For this reason, it is expensive and extremely difficult to handle when mounting it on equipment. Furthermore, the atomization properties were not sufficient, particularly in terms of uniformity of the atomized particle size. Further, since a liquid supply means such as a pump is required and the amount of atomization is determined by the liquid supply means, the atomization apparatus as a whole has to become larger and more expensive.

The second atomization device is one that has been put into practical use in humidifiers, etc.
An ultrasonic vibrator is attached to the bottom of the liquid tank, and ultrasonic waves are concentrated on the liquid surface to form a liquid column on the liquid surface, making use of a type of cavitation (sometimes referred to as capillary waves) on the liquid surface. and atomizes it. This atomizer atomizes directly from the liquid level in the liquid tank, so it does not require a liquid supply means such as a pump. However, depending on the relative distance between the liquid level and the vibrator, the liquid temperature, etc. movement is significantly affected,
This method has the disadvantage that it is difficult to stabilize the amount of atomization.

In addition, in order to obtain good atomization operation, the frequency is 1 to 2 MHz.
, which requires a large amount of power at an extremely high frequency of 20 to 50 Watts, and has the advantage of producing atomized particles with extremely small diameters, but has the disadvantage of large variations in the atomized particle diameters. was. Furthermore, due to problems with its operating frequency range, it has a serious drawback in that it tends to cause radio wave interference to various devices such as radios. Furthermore, since the drive circuit needs to generate high frequency and large power as mentioned above, it has to be extremely expensive, and it also requires a filter device for suppressing radio wave interference, making it even more expensive. Ta.

The present invention has been made in view of the above points.51'-
”, which is a relatively small atomization device that uses ultrasonic waves,
The aim is to provide an atomization device that eliminates the above-mentioned drawbacks while taking advantage of the advantages of low noise and excellent controllability due to easy electrical control. The present invention aims to realize an atomizing device that consumes less power and has excellent atomizing characteristics.

An embodiment in which the present invention is applied to a liquid fuel burner will be described below with reference to the drawings.

FIG. 1 is a sectional view of a hot air heater to which an embodiment of the atomization device of the present invention is applied. In FIG. 1, reference numeral 1 denotes a hot air fan case, and an operating section 2 is provided on the second side of the case, and is used to issue control commands to a controller 3.

When an operation command is given to the controller 3 from the operation unit 2, the burner motor 4 is started, and the combustion fan 5 mounted on the same axis is activated.
, the suction fan 6 is activated. Therefore, the combustion air passes through the orifice 8 from the intake lower, and is sent into the mixing chamber 1o by the swirler 9 as a swirling airflow as shown by the arrow.

61-' On the other hand, kerosene passes from Kunku 11 to Leveler 1 via pipe 12.
3, and the liquid level when the operation is stopped is controlled to the position of the liquid level 15 in the pipe 14. As described above, when the combustion fan 6 and the suction fan 6 are operated by the operation of the burner motor 4, the orifice 8 causes the coupling portion 16 to have a negative pressure P.
1 occurs.

Further, the suction fan 6 generates a differential pressure P2 between the joint portion 16 and the suction portion 17. Therefore, suction part 1
7 is in a negative pressure state by Po=P, +P2 with respect to atmospheric pressure. Due to this negative pressure Po, the liquid level 15 of kerosene rises,
The inside of the atomizing section 18 is filled with kerosene, and the liquid level is balanced at the position of the liquid level 2o in the pipe 19, as shown in the figure. The atomizing section 18 is attached to the wall surface 21 of the mixing chamber 10 at an angle as shown in the figure.

The atomizing section 18 is energized by a drive circuit within the controller 3 as will be described later, and discharges atomized particles 22. Atomized particles 2
2 is mixed with air in the mixing chamber 1o to form a main flame 2 and an auxiliary flame 28. The auxiliary flame 28 is for sufficiently increasing the temperature of the vaporizing section 23. Therefore, flame 27.2
8 is not a complete blue combustion flame at the initial stage of ignition, but the vaporization part 2
3 becomes a complete Yr flame when heated sufficiently. 29 is 2
It is a second air outlet, which suppresses the combustion speed of the flame 27 to a low level,
This aims to reduce the harmful substances in the gas discharged from the exhaust pipe 30, and since only a small amount of primary air is required, the concentration of atomized particles in the mixture ejected from the main flame port 24 can be increased. This has the effect of improving ignition by the igniter 26. Reference numeral 31 is a flame detection means that sends flame status signals such as ignition, misfire, air-fuel ratio, etc. to the controller 3.

Further, 32 is a convection fan that sends indoor air to the heat exchanger 33 and discharges warm air indoors.

Here, regarding the operation of the atomization device of this embodiment, Fig. 2a
, b. 2a, b In FIG. 2a, the base body 34 has a cylindrical shape with a diameter of about 40 words, and as is clear from its axial cross-sectional view, a horn-shaped pressurizing chamber 36
It has inside. The tip of the pressurizing chamber 36 has a diameter of 30~
A nozzle part 3 provided with a nozzle 36 of about 80 μm is sealed with a packing 38 and fixed with a holding plate 39.

On the other hand, at the rear end of the pressurizing chamber 35 there is a diaphragm 4o with a diameter of 10 to 2
An electric vibrator 42 consisting of a disc-shaped piezoelectric element 41 of approximately 0 pieces is provided, a fixing part 43 is made integrally with a diaphragm 40, and is attached to the base 34 while being sealed with an O ring 44. There is.

A supply chamber 46 communicated with the pressurization chamber 35 through the communication section 45 is configured to surround the entire circumference of the electric vibrator 42, and is provided with a discharge section 47 for discharging gas in the pressurization chamber 35 into the supply chamber. , a supply section 48 to which liquid is supplied is provided, respectively.
A pipe 19 and a pipe 14 are attached.

When an alternating current voltage (alternating power) is supplied to the electric vibrator 42, it emits a drum shape as shown in FIGS. 2a and 2b.

Now, when a positive half-cycle voltage is applied to the electric vibrator 42, the state shown in FIG.
From the nozzle 36, droplets 2 with minute and uniform particle size are produced.
2 is ejected.

Conversely, when a negative half-cycle voltage is applied to the electric vibrator 42, the state shown in FIG. 2 occurs, and negative pressure is generated near the electric vibrator 42 due to the strain. Therefore, kerosene is sucked in from the supply chamber 46 as indicated by the arrow in the figure, and kerosene is supplied to the supply chamber 46 from the leveler 13 via the pipe 14. At this time, the nozzle 36 remains sealed due to the surface tension effect of the kerosene as shown in the figure, and therefore,
There is no inflow of air from nozzle 36. In other words, it has a self-sufficient effect.

By repeating the above operations, the kerosene will reach level 13.
is automatically sucked into the pressurizing chamber 35, and then the nozzle 3
From 6, stable atomized particles with small particle size and uniformity are ejected.

Since the driving power of the electric vibrator 42 is only required to pressurize the liquid (kerosene), there is no need to obtain large mechanical vibration energy as in the conventional case. It is possible to make it about 1/1 to 17,100 of a conventional ultrasonic atomizer.

Figure 3 a'' = d is a characteristic diagram of the atomizer shown in Figures 2 a and b. Figure 3 a shows the driving voltage v0 and atomized particles when the frequency f is kept constant at f = f. This shows the relationship between the particle size d of q=q+), the higher the drive frequency f., the smaller the particle size d can be obtained.

Furthermore, as shown in FIG. 3C, the relationship between the 11. , tz't K ” fO' K : A constant relationship.

Pressure P where there is pressure (negative pressure) P. When the temperature reaches this point, bubbles are generated due to cavitation, and when these bubbles grow and become excessively large, the atomization operation becomes unstable, and eventually the nozzle 36 is blocked and the atomization operation stops. . That is, the drive frequency f. is f. When -fc is reached, the atomization operation becomes unstable as described above. Therefore, fo≧f.

A frequency f such as . If the atomizing device is driven with a continuous waveform as shown in FIG. 4(d), the atomizing operation described above will become unstable.

FIGS. 5a and 5b show the generation of bubbles due to the cavitation described above. When the electric vibrator 42 is driven by an alternating current voltage (fo>fo) with a continuous waveform as shown in FIG. is clayey. Then, while the electric vibrator 42 continues to vibrate, the microbubbles 49 to 61 either remain near the place where they are generated or gradually move toward the nozzle 36. Then, after a certain period of time, the microbubbles will grow as shown in Figure 5, and the bubbles will become bubbles 4≦, 5C5, 51', and these bubbles will move and combine as shown by the arrows in the figure, causing the bubbles to become too large. bubble 52
becomes. In such a state (FIG. 5b), the strain generated by the electric vibrator 42 is no longer able to generate effective pressure, and the ejection direction of the micro droplets 22 becomes unstable as shown in the figure. Or, it may become almost impossible to dispense.

Therefore, it is necessary to drive the electric vibrator 42 at a frequency such that fo<fo71i: This puts a limit on the atomization of the ejected droplets 22 and makes it impossible to eject droplets with even smaller particle sizes. It means something.

FIG. 6 shows a high frequency f while preventing the above-mentioned disadvantages and preventing the atomization operation from becoming unstable due to cavitation bubbles. FIG. 3 is a block diagram showing a vibrator drive unit 63 and an intermittent control unit 54 that can be driven by (foΣfc) and therefore can eject extremely small droplets.

The vibrator drive section 63 is composed of a power supply section 66, a first oscillator 56, and an amplifier 57, and supplies an alternating voltage to the electric vibrator 42. On the other hand, the intermittent control section 64 includes a second oscillator 68;
It consists of a switch circuit 59 driven thereby. The output of the first oscillator 66 is configured to be switched on and off by the switch circuit 59, which is turned on and off by the output of the second oscillator 58. A voltage obtained by amplifying the intermittent waveform output voltage by an amplifier 57 is supplied. Figure 4, cF
The operation described above is shown in FIG.
The output waveform of the first oscillator 56 is the operating waveform of the second oscillator 68, and the output waveform of the first oscillator 56 is transmitted to the amplifier 57 by the switch circuit 69 only during the period TON in the cycle Ttotd in the figure. It is shown that. Therefore, it indicates the state of the electric vibrator, which rises as indicated by the arrow in the figure, combines to form a bubble 60, and is discharged from the exhaust section 47.

That is, the electric vibrator 42 is activated only during a certain TOFF period.
By stopping the operation of the bubbles 49 to 51, the bubbles 49 to 51 can be stopped before they grow and the atomization operation becomes unstable.
can be emitted, and the high frequency fa (fa 〉f
c) Stable atomization operation can be maintained even in the case of

Of course, TON is T before bubbles 49 to 51 grow.
It is necessary that the time is sufficiently short (compared to the growth of the bubbles) so that the TOFF period is long enough to allow the bubbles 49 to 61 to rise outside from the pressurizing chamber 35. It is necessary that it is time.

Therefore, when this intermittent control means is also used as the atomization amount control means to simplify the circuit configuration and reduce costs, the TON shown in FIG. 4, c, is the limit.

” ['OFF If the atomization amount is adjusted, it is necessary to do as shown in Figure 4 C1e when adjusting the atomization amount. In other words, TON (TOFF) when adjusting the atomization amount is It is necessary that the time is shorter (longer time) than the limit value,
By doing so, it is possible to provide an atomizing device with a simple structure and excellent atomization characteristics while ensuring the stability of the atomizing operation when adjusting the atomization amount.

FIG. 7 shows a more detailed embodiment of the vibrator drive section 63 and intermittent control section 54 shown in FIG.

In the figure, the power supply unit 56 consists of DC power supplies 61 and 62, which can be easily obtained from a commercial power source via a transformer if necessary.

The first oscillator 66 consists of transistors 63, 64, capacitors 65, 66, and resistors 67 to 70, and is configured in a so-called multi-by-break configuration. transistor 6
The collector output of 4 is a field effect transistor (FET)
) 71, transistors 72, 73, capacitor 7
4. The signal is supplied to the amplifier 57 via a switch circuit 69 consisting of resistors 75-78. The amplifier 6 has transistors 79 to 81, capacitors 82, 83, . Resistor 84-8
γ, and an output lance 88, and the output of the output lance 88 is configured to be supplied to the electric vibrator 42. On the other hand, the second oscillator 58 is a transistor 89
,90. Consisting of capacitors 91 and 92, resistors 93 to 97, and interlocking variable resistors 98 and 99, the output of which is connected to F via transistors 72 and 73 of switch circuit 59.
Controls on/off of ET71. That is, the output of the second multi-by-break that constitutes the second oscillator causes F
Since ETγ1 turns on and off, the output of the first multivibrator constituting the first oscillator 66 is intermittently supplied to the amplifier 57.

Therefore, the electric vibrator 42 has the variable resistor 98
．． F as shown in Fig. 4 C1e that occurs depending on the setting value of 99.
As the voltages shown in Fig. 4 and d are supplied as ITγ1 is turned on and off, the operations shown in Fig. 5 a and C can be repeated depending on the TON, T, and x periods, respectively.
7 In this way, by configuring the second oscillator 68 to turn on and off the first oscillator 660 for exciting the electric vibrator 42, it is possible to drive at a high frequency fo (fo>tc). This makes it possible to provide an atomization device that is stable without being affected by cavitation bubbles and has excellent atomization characteristics.

The variable resistors 98 and 99 have an interlocking configuration, and are connected so that the respective resistance values increase and decrease due to adjustment. Therefore, in this embodiment, the variable resistor 98
．． By adjusting 99, T totaR is constant,
The amount of atomization is controlled such that TON and TOFF are increased or decreased, and the drive waveform is as shown in Figure 4, d.

The resistor 95 is a minimum stop time regulating means that limits the minimum value of TOFF, and at the same time, together with the variable resistor 98°99 and the resistor 94, it also plays the role of a maximum driving time regulating means that regulates the maximum value of TON. .

In this way, by providing the minimum stop time regulating means and the maximum driving time regulating means, as described above, stable discharge of cavitation bubbles from the pressurizing chamber 36 can be guaranteed, and the atomization operation can be improved. It is possible to achieve stable continuation of

As described above, according to the present invention, a nozzle part having a nozzle and an electric vibrator are attached to a base body having a pressurizing chamber, and the electric vibrator is driven by a vibrator driving part. Since an intermittent control section is provided to drive the electric vibrator intermittently, the structure is simple and compact, and furthermore, it consumes less power and has a liquid self-sufficiency function. It is possible to realize an extremely low-cost atomizing device, and furthermore, it is possible to provide an atomizing device that can stably generate a large amount of uniform atomized particles of extremely small particle size. In addition, intermittent operation prevents the growth of cavitation bubbles and enables stable operation at high frequencies, making it possible to create an atomization device with even better atomization characteristics, and its industrial value is extremely high. It is.

[Brief explanation of the drawing]

19' Fig. 1 is a sectional view of an embodiment of the present invention applied to a hot air heater, Figs. 2 a and b are enlarged sectional views illustrating the operation of the atomizing section, and Figs. 3 a, b, and c. , d are characteristic diagrams, Fig. 4 a, b, c,
d and θ are voltage waveform diagrams for explaining the driving method of the electric vibrator, and FIGS. 6a and 6b. C is an enlarged sectional view illustrating the state of cavitation bubbles, FIG. 6 is a block diagram showing one embodiment of the vibrator drive section and the intermittent control section, and FIG. 7 is a more detailed diagram of the vibrator drive section and the intermittent control section. FIG. 2 is a circuit diagram showing an example. 34... Base body, 36... Pressurized chamber, 36
... Nozzle, 37 ... Nozzle part, 42
. . . Electric vibrator, 63 . . . Vibrator drive section, 64 . . . Intermittent control section. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 3 f.

Claims (4)

[Claims] (1) a base body having a pressurizing chamber; a nozzle section mounted on the base body and provided with a nozzle; an electric vibrator mounted on the base body and vibrating the liquid in the pressurizing chamber; a vibrator drive unit that supplies alternating power to the target vibrator;
An atomization device including an intermittent control section that intermittently controls supply of the alternating power to the electric vibrator. (2) The base body is provided with a discharge section for discharging the gas in the pressurized chamber, and the gas is discharged from the discharge section when the intermittent control section stops operating the electric vibrator. Atomization device according to scope 1. (3) The atomization device according to claim 1, wherein the intermittent control section is configured to also serve as an average atomization amount control section that controls the average value of the atomization amount. (4) The intermittent control unit includes a maximum driving time regulating means that regulates the maximum time during which the electric vibrator is continuously driven, and a minimum time during which the electrical vibrator is continuously stopped. The atomization device according to claim 3, further comprising at least one of the minimum stop time regulating means.