JPS605259A - Atomizing apparatus - Google Patents

Abstract

PURPOSE:To stably perform the spray operation of a liquid by keeping the pressure chamber constant, in an apparatus for atomizing and spraying the liquid by an electric vibrator, by providing a suction pump and a damper to the discharge line communicated with the pressure chamber of the liquid. CONSTITUTION:A nozzle plate 16 having a large number of fine jet orifices 15 is attached to the front surface of a liquid pressure chamber 13 provided in a body 14 and an electric vibrator 18 such as a piezoelectric vibrator is further attached to said chamber 13. A liquid such as liquid fuel such as kerosene or light oil, water, a chemical liquid or ink is introduced into the pressure chamber 13 from a supply pipe 21 through a leveler 22 and sprayed in a mist form 30 from the fine orifices 15 by the vibration of the piezoelectric vibrator 18. In this case, a negative pressure generating part 25 communicated with a suction pump 26 and a damper 27 is provided to an exhaust pipe 24 communicated with the pressure chamber 13 and proper negative pressure is applied to the liquid in the pressure chamber 13 by the operation of the suction pump 26 and the adjustment of the opening degree of the damper 27 to always keep the liquid lever F constant. By this method, the penetration of air into the pressure chamber 13 and the flooding of the iquid from the exhaust pipe 24 are prevented to stably perform spraying work.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an atomization device for atomizing various liquids such as liquid fuels such as kerosene and light oil, water, chemicals, and recording inks. The present invention relates to a spray device that sprays liquid and atomizes it by vibration of an electric vibrator such as a piezoelectric vibrator.

Conventional configurations and their problems Various configurations have been proposed for this type of atomization device, mainly as an ink atomization device for inkjet recording devices, and in recent years, a configuration as shown in Fig. 1 has been proposed. Atomization devices have been proposed.

In FIG. 1, a plurality of nozzles 2 are provided at one end of a liquid chamber 1 as shown in the figure, and a diaphragm 3 and a piezoelectric vibrator 4 are mutually bonded to a body 6 [attached to the other end]. There is.

The liquid chamber 1 is connected to a tank 7 by a vibrator, and a vibrator 8 is further provided as shown in the figure.

The tank 7 is connected to a pressure pump 10 through a vibrator 9, and is configured so that a pressure P1° generated by the pressure bomb 10 is applied to the liquid level A.

When the pressure bomb 10 is activated and pressure P1° is applied to the liquid level AK, the liquid level B in the vibro is pushed up and the vibrator 8
The liquid level inside becomes C, and the state is as shown in the diagram. That is, when the difference in height between liquid levels B and C is h1 and the density of the liquid is ρ, Pl. = ρ・h and there is a balance.

Next, an alternating current voltage as shown in FIG. 2 is applied to the piezoelectric vibrator 4, and the bimorph vibrating body composed of the diaphragm 3 and the piezoelectric vibrator 4 causes deflection vibration as indicated by the broken line in the figure. The pressure wave caused by this accumulated vibration is amplified while propagating through the liquid in the liquid chamber 1, reaches the nozzle 2, and a droplet 11 is ejected as shown in the figure.

However, such conventional atomizing devices have the following problems.

The pressure P1o generated by the pressure pump 1o, which prevents the filling of liquid from the tank 7 into the liquid chamber 1, is Pl as described above. By satisfying the relationship -ρ·h, it is possible to realize the state shown in FIG. 1, that is, the state in which the liquid chamber 1 is filled with liquid. However, Pl. If h=P10//ρ>h' (h/ is the difference in height between the liquid level B and the tip of the pipe 8) due to fluctuations in the liquid density ρ or changes in the liquid density ρ, This has disadvantages in that liquid overflows from the tip and liquid drips from the nozzle 2. Conversely, if h=P10//ρkuh"(h" is the difference in height between the upper end of liquid chamber 1 and liquid level B), air exists in liquid chamber 1, and piezoelectric imaging This causes a problem in that the pressure waves generated by the droplet 4 are not effectively transmitted to the nozzle 2 and end up falling back.

OBJECTS OF THE INVENTION The present invention aims to provide an atomizing device that eliminates the above-mentioned drawbacks of the conventional atomizer, and eliminates the disadvantages such as wet fields of liquid from the liquid chamber and an air layer forming in the liquid chamber and not being filled with liquid. It is an object of the present invention to provide an atomizing device that can completely prevent the above problems, ensure safe and good spraying operation, and can easily fill the liquid chamber with liquid.

Configuration of the Invention In order to achieve the above object, the present invention has the configuration described below.

That is, a pressurizing chamber, a nozzle facing the pressurizing chamber, a liquid supply path and an exhaust path connected to the pressurizing chamber, and a liquid supply path and an exhaust path connected to the exhaust path generating negative pressure for filling the pressurizing chamber with liquid. A device comprising a negative pressure generating means, an electric vibrator that vibrates the liquid in the pressurizing chamber and sprays it through a nozzle, and a negative pressure adjusting means that adjusts the magnitude of the negative pressure. With this configuration, liquid can be easily filled into the pressurized chamber,
In addition, the static pressure of the liquid in the pressurized chamber and the height of the liquid level in the exhaust path are maintained in a good state without the disadvantages of the prior art.

Description of examples An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a sectional view of an atomizing device showing one embodiment of the present invention.

In FIG. 3, the atomizing section 12 has a diameter of 5 to 16 mm inside.
A body 14 having cylindrical pressure chambers 13 with depths of 1 to 5, a plurality of nozzles 15 with a diameter of 30 μm to 100 μm, a nozzle plate 16 with a thickness of 3 μm to 100 μm, and an opening 17 in the center. It has a diameter of 5~16 mm and a thickness of 06~
It consists of two piezoelectric vibrators 18, which are bonded to each other as shown in the figure, and attached to the mounting plate 20 with screws 19.
is fixed. The pressurizing chamber 13 is connected to a leveler 22 that maintains the liquid level at a substantially constant level through a liquid supply path 21, and the leveler 22 is connected to a tank (not shown) through a pipe 23 to form a liquid supply system. ing.

An exhaust path 24 is further connected to the pressurizing chamber 13.
4 is connected to the negative pressure generating section 26.

The negative pressure generating section 26 includes a suction pump 2 which is a negative pressure generating means.
6 and a damper section 27, which is a negative pressure adjusting means for adjusting the magnitude of the negative pressure -P generated in the negative pressure generating section 25, through pipes 28 and 29, and the suction pump 26
The air sucked into the damper part 2 as shown by the arrow in the figure.
The amount of air Q flows according to the opening degree of 7.

When the suction pump 26 is stopped, the pressure of the negative pressure generator 25 is equal to the atmospheric pressure, −P=o, and therefore the liquid supply path 2
The liquid level E in 1 is at the same height as the liquid level. Suction pump 2
6 is started, the relationship between the amount of air sucked by the suction pump 26 and the magnitude of the negative pressure -P generated in the negative pressure generating section 25 is as follows on the curve t1 in FIG. Point a according to opening degree θ=θ1 Q=Q −P=−Pl
Tona 1 Tsuru.

Due to this negative pressure -P1, some air inflows from the nozzle 16 and flows in the exhaust passage 24 as shown by the arrow in the figure, but the amount of air is extremely small because the nozzle 16 has a small hole diameter. A pressure equal to P1 is applied to the surface E.

Therefore, the liquid level E rises, fills the pressurizing chamber 13 with liquid, and further rises, becoming the liquid level F at a predetermined position in the exhaust path 24 and balancing.

The difference in height between this balanced position and the liquid level E satisfies -P=-P1=-ρ・h, where the density of the liquid is ρ.The damper section is designed to satisfy this condition. By adjusting the opening degree θ of 27, the position of point a in FIG. 4 can be obtained.

The function of the damper section 27 is extremely important. For example, it is clear when considering the case where the suction pump 26 changes its suction capacity due to a change in the voltage or frequency of the power supply, and becomes like the curve t2 or t3 in FIG. 4. That is, when the opening degree θ of the damper section 27 cannot be adjusted, the operating point a in FIG. The negative pressure -P becomes -P71 or -P%, and the liquid level F is lower than hl in Fig. 3.
When the pressure decreases and an air layer is created in the pressurizing chamber 13, the liquid level F rises to a position higher than h2, causing the inconvenience that the liquid overflows through the exhaust path 24. However, due to adjustment of the opening degree θ of the damper portion 27, t2. Adjust θ=θ2, θ=θ3 according to t3, Q=02 or Q=Q3
By doing so, the operating point α can be moved to β or γ to maintain the negative pressure −p = −pl, and as a result, the height b of the liquid level F can be kept constant and the above-mentioned disadvantages can be prevented. can.

Furthermore, it is possible to adjust −P and adjust the preferred liquid level height bK not only in response to changes in the suction capacity of the suction pump 27 but also in response to changes in density ρ due to changes in the type of liquid. can.

In this way, the pressurizing chamber 13 can be easily and reliably filled with liquid so that a good liquid level F is achieved.

Next, an AC voltage as shown in FIG. 6a, b or c is supplied to the piezoelectric vibrator 18 according to the average amount of spray to be sprayed. The piezoelectric vibrator 18 is provided with electrodes (not shown) on the adhesive surface with the nozzle plate 16 and on the opposite surface thereof, and causes expansion and contraction strain in the diametrical direction according to the polarity of the AC voltage, and this expansion and contraction strain Since the piezoelectric vibrator 18 and the nozzle plate 16 are bonded to each other, the vibration is converted into a flexural vibration as shown by the broken line in the figure. As a result, a bending vibration is generated in which the vicinity of the nozzle 16 is greatly vibrated, and the liquid in the pressurizing chamber 13 is pressurized only in the vicinity of the nozzle 15 and is ejected as droplets 30 as shown in the figure. It is atomized.

Since the configuration is such that only the vicinity of the nozzle 16 is strongly vibrated, bubble nuclei due to cavitation are ejected from the nozzle 15 before they grow into air bubbles, and therefore contain a large amount of dissolved air. Even liquids can be stably sprayed without being affected by cavitation bubbles. Further, a volume of liquid corresponding to the sprayed liquid is naturally sucked up from the liquid supply path 21 by the surface tension effect of the liquid generated in the nozzle 15, thereby achieving a self-sufficient pumping action.

Therefore, although it has a very simple configuration, it is possible to realize an atomization device that can easily and reliably fill the pressurizing chamber 13 with just the right amount of liquid and spray it under various conditions. It is.

FIG. 6 is a sectional view of an atomizing device showing another embodiment of the present invention, and the same reference numerals as in FIG. 3 indicate corresponding structures, and the explanation thereof will be omitted.

In FIG. 6, the negative pressure generating means for generating negative pressure -P in the negative pressure generating section 25 consists of a blower 77 fan 31 and a motor 32 that drives it. The air flows as shown by the arrow in the figure through the damper 34, which serves both as a negative pressure regulating means for regulating the magnitude of the pressure -P and as a flow regulating means for regulating the amount of air blown by the blowing fan 31. As shown in the figure, the damper 34 is configured to be detachable so that it can be replaced with a damper having a different size of orifice 35 depending on the capacity of the fan 31 and the type of liquid to be sprayed. Can be adjusted.

The air blown by the blower fan 31 further passes through the ventilation holes 36 and 37 of the mounting plate 20, is ejected from the ejection port 38 as shown in the figure, and is configured to mix with the jetted N droplets 3o and transport them. .

With such an extremely simple configuration, the pressure chamber 13 can be easily filled with liquid by starting the blower fan 31, and the height h of the liquid level F can be increased by adjusting the damper 34.
To realize an atomizing device that can set an appropriate value of h2, prevent the generation of liquid seamounts and air pockets in a pressurizing chamber 13, and perform safe and reliable atomizing operation. is possible.

FIG. 7 is a cross-sectional view showing the configuration of a combustion device to which an atomizer according to still another embodiment of the present invention is applied.

In FIG. 7, the same reference numerals as in FIG. 6 indicate corresponding structures, and their explanation will be omitted.

In FIG. 7, kerosene is sent from a leveler 22 through a pipe 21' to a liquid tank 39 having a liquid level E', and a negative pressure -P generated by a combustion fan 31 is applied.
The structure is such that the liquid level E is sucked up to the liquid level F and the pressurizing chamber 13 is filled with kerosene.

The combustion air is sucked in through the suction port 33, and the amount of air determined by the airflow rate adjusting damper 4o is sent to the airflow path 41.
Mixing with the spray droplets 30 through the spout 38 1~, heater 4
2 to the vaporization section 43 having the secondary air path 4.
4, and forms a flame 47 in a primary combustion chamber 45 and a secondary combustion chamber 46, where it is combusted. In addition, 48 is a heat exchanger,
49 is an exhaust pipe.

The negative pressure -P is adjusted by the negative pressure adjustment damper 60 as follows. The amount of air that bypasses through the bypass path 51 is configured to be sufficiently smaller than the amount of air that is adjusted by the air flow rate adjusting damper 40 through the orifice 62. Therefore, the first negative pressure generating section 2 upstream of the blower fan 31
The negative pressure -P' of 6' is determined by the opening degree of the air flow rate adjusting damper 40.

When the supply voltage to the piezoelectric vibrator 18 is adjusted to adjust the spray amount and change the combustion amount as shown in FIG. 6 a, b or c,
It is necessary to keep the air-fuel ratio constant by following the combustion air amount oB, and when the air blowing amount adjusting damper 4o is adjusted, the air blowing amount QB changes from QB1 to QB2 as shown in FIG. At this time, the relationship between the negative pressure p/ and oB becomes a locus that moves along a curve.

Therefore, the magnitude of -P' changes as shown in the figure.
If the configuration is such that only this negative pressure is directly applied to the liquid level F, excessive fluctuations in the height of the liquid level F will occur, causing problems such as kerosene seamounts. may occur.

Therefore, the negative pressure regulating damper 50 is adjusted in conjunction with the air flow regulating damper 4o, and both dampers are constructed in conjunction with each other so that the amount of air flowing through the orifice 52 increases as QB decreases. There is. Therefore, the pressure loss ΔP in the orifice 62 increases as QB decreases, resulting in a curve t' in FIG.

As is clear from the configuration of FIG. 7, the second negative pressure generating section 25
The relationship between the negative pressure -P of the orifice 62, the pressure loss ΔP1 of the orifice 62, and the negative pressure -P' of the first negative pressure generating part is -P/=-(P+△P), so -P=-(P /-△P).

Therefore, by appropriately configuring both dampers 40 and 5o, the difference between curves t and t' can be kept constant regardless of QB, as shown in FIG. 8, and -P can be kept constant regardless of changes in QB. .

With this configuration, even if oB is adjusted to adjust the combustion amount, the height of the liquid level F is maintained constant, eliminating the risk of inconveniences such as overflow of kerosene. It is also possible to easily fill the pressurized chamber with kerosene. With the above-described configuration, a combustion device to which the atomization device of one embodiment of the present invention is applied can be a combustion device that has an extremely simple configuration, has high safety, and is easy to use.

Effects of the Invention As described above, according to the present invention, the nozzle is made to face the pressurizing chamber, and the liquid is sprayed by the electric vibrator at vibrations 1 to 1, and the pressurizing chamber is provided with an exhaust path and a liquid supply path. At the same time, a negative pressure generating means for generating negative pressure for filling the pressurized chamber with liquid is connected to the exhaust path. 1-1 Negative pressure adjusting means for adjusting the magnitude of the negative pressure is provided. With its extremely simple configuration, the pressurized chamber can be filled with liquid very easily, and the pressurized chamber is reliably filled with liquid without causing inconveniences such as liquid overflow, resulting in stable spraying operation. It is possible to provide an atomization device that can guarantee the following, and its industrial value is extremely large.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional atomizing device, Fig. 2 is a drive voltage waveform diagram of a piezoelectric vibrator of the same device, Fig. 3 is a sectional view of an atomizing device according to an embodiment of the present invention, and Fig. 4 Figure 5a and b are relationship diagrams between negative pressure and air volume to explain the liquid level height of the same atomization device.
and C are driving voltage waveform diagrams of the piezoelectric vibrator depending on the size of the spray amount of the same atomizing device, FIG. 6 is a sectional view of an atomizing device of another embodiment of the present invention, and FIG. 7 is a diagram of another example. FIG. 8 is a sectional view of a combustion device to which the atomization device of the embodiment is applied. FIG. 8 is an explanatory diagram of the relationship between the air amount and negative pressure of the combustion device. 13... Pressure chamber, 16... Nozzle, 1
8... Electric vibrator, 27... Liquid supply path, 24... Exhaust path, 26... Negative pressure generating means (suction pump), 27 ...Negative pressure adjusting means (damper section), 31.32...Negative pressure generating means (31...Blower fan, 32...Motor), 34 ...Negative pressure adjustment means (damper), 50
...Negative pressure adjustment means (negative pressure adjustment damper). Name of agent: Patent attorney Toshio Nakao and 1 other person No. 4
Figure 5

Claims (1)

[Scope of Claims] (1) A pressurizing chamber, a nozzle provided facing the pressurizing chamber, a liquid supply path and an exhaust path connected to the pressurizing chamber, and a liquid supply path and an exhaust path connected to the exhaust path. A negative pressure generating means for generating negative pressure for filling the pressurized chamber with liquid; and an electric vibrator that vibrates the liquid in the pressurized chamber and sprays it from the nozzle, and the negative pressure Negative pressure regulating means for regulating the size of the atomizer. (2) The atomizing device according to claim 1, wherein the negative pressure generating means is configured to also serve as a blowing means for blowing gas to be mixed with the droplets sprayed from the nozzle. (3) The negative pressure generating means is constituted by a blowing means, and a flow rate adjusting means for adjusting the gas flow rate is provided in the suction flow path of the blowing means,
The atomization device according to claim 1, wherein the flow rate adjustment means constitutes a negative pressure adjustment means.(4) The flow rate adjustment means is used to adjust the total air volume to adjust the total amount of gas blown by the blowing means. An atomizing device according to claim 2 or 3, which also serves as a means. (5) The atomization device according to claim 2, wherein an air volume adjustment means is provided to adjust the amount of gas blown by the air blowing means, and the negative pressure adjustment means and the air volume adjustment means are controlled in conjunction with each other. .