JPS6161869B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an atomization device for atomizing liquid fuels such as kerosene and diesel oil, and liquids such as water and medical solutions, and more specifically relates to an atomization device for atomizing liquid fuels such as kerosene and diesel oil, and liquids such as water and medical solutions. This invention relates to an atomization device that applies the above.

The first object is to provide an atomizing device that is simple in construction, compact and therefore inexpensive. The second objective is to provide an atomization device with low power consumption and excellent atomization characteristics. A third object is to provide an atomizing device that has stable atomizing operation and low noise.

BACKGROUND ART Conventionally, various types of liquid atomization devices have been put into practical use or are being considered for practical use.

For example, (1) a rotary atomizer that drips liquid onto a high-speed rotating body and atomizes it by shaking off the liquid using centrifugal force, (2) pressurizes the liquid to several kg/cm ² using a high-pressure pump, etc., and sprays it from a nozzle. (3) A horn-shaped vibrator is made of duralumin or the like, and the amplitude of the piezoelectric element or magnetostrictive vibrator is increased by the horn-shaped vibrator, and A width-enhancing ultrasonic atomizer that supplies liquid to the tip of the horn and atomizes it; (4) A piezoelectric vibrator is installed at the bottom of the liquid tank to concentrate ultrasonic waves near the liquid surface of the liquid tank; There are direct ultrasonic atomizers that use a type of cavitation phenomenon near the liquid surface to atomize the liquid.

However, atomization devices such as those mentioned in (1) and (2) above require large parts such as a rotating body and a high-pressure pump, making the entire device larger and more expensive, and the atomization characteristics are not sufficient. The noise was also loud. In addition, (3) requires a horn-shaped vibrator made of duralumin, etc., and the horn shape and dimension accuracy required to obtain stable and reliable vibration of this vibrator is extremely strict, and therefore expensive. In addition, the atomization performance was not good. In addition, in order to increase the mechanical amplitude efficiently and stably, an expensive drive circuit with a stabilized output is required, and furthermore, the mounting structure has to be complicated. .

In addition, in (1) to (3) above, it is necessary to supply the liquid with a liquid supply means such as a pump, and the amount of atomization is determined by this liquid supply means, so the amount of atomization is stable. This requires an expensive liquid supply means.

Although (4) above does not require a liquid supply means as mentioned above because it is atomized directly from the liquid tank, it has a structure in which ultrasonic energy is irradiated directly into the liquid tank and atomization is caused by the ultrasonic energy itself. Because there is
The atomization characteristics are significantly affected by the temperature of the liquid to be atomized, the distance between the liquid surface and the vibrator, etc., and the energy required for atomization is extremely large.
Operation at frequencies in the 1-2 MHz band was necessary for efficient atomization operation. Therefore, there was a serious problem in that an extremely large amount of unnecessary radiation was generated.
Due to these conditions, the drive circuit had to be extremely expensive in order to stabilize the amount of atomization and suppress unnecessary radiation.

The present invention has been made in view of these points, and eliminates the above-mentioned conventional drawbacks by making the small hole nozzle tapered, and has a simple and compact structure, and is therefore inexpensive. It is an object of the present invention to provide an atomization device that has excellent atomization characteristics, consumes low power, and is stable and generates low noise.

An embodiment in which the atomization device of the present invention is applied to an oil hot air heater will be described below with reference to the drawings, but the present invention is not limited to this embodiment.

FIG. 1 is a cross-sectional view of a hot air heater showing an embodiment of the present invention.

In the figure, 1 is a hot air fan case, and an operating section 2 is provided on the top surface. Reference numeral 3 denotes a control section, which has a function of controlling the operation of the hot air fan. Kerosene, which is a fuel, is supplied from an oil tank 4 through a pipe 5 to a leveler 6 that controls the liquid level to be substantially constant.
Further, it is sent from the leveler 6 through a pipe 7 to a degassing section 8. The deaeration section 8 is for reducing the amount of air dissolved in the kerosene and further improving the atomization performance as described below. The kerosene thus produced is supplied to the atomizing section 12 through the pipe 11.

On the other hand, combustion air is sucked in from an intake pipe 15 as shown by the arrow in the figure by a blower fan 14 attached to the rotating shaft of a motor 13, and is sent to a swirler 17 through an orifice 16. Combustion air is supplied to the atomization mixing chamber 18 by the swirler 17 while giving a rotational motion as shown by the arrow in the figure, and mixes with the atomized particles 19 discharged from the atomization section 12 to form the opening 20 of the atomization mixing chamber 18.
It is then sent to the heat exchanger/combustion chamber 21. This air-fuel mixture is ignited by the ignition means 22 to form a rotating flame 23 as shown in the figure. Reference numeral 24 is a flame rod which detects the flame state and sends a signal thereof to the control section 3. Moreover, 25 is a ventilation fan, which causes indoor air to circulate through the heat exchanger 21.

Here, when starting the atomizer 12, the deaerator 8
A method for filling the atomizer 12 with the deaerated kerosene will be explained. As shown in the figure, a suction fan 26 is attached to the shaft of the motor 13 that drives the ventilation fan 14.
is provided and operates to send air as shown by the arrow in the figure. That is, the outlet 27 of the suction fan 26 is connected downstream 28 of the orifice 16,
The inlet 29 of the suction fan 26 is configured to have a more negative pressure than the downstream 28 of the orifice 16. A suction pipe 30 is connected to the inlet 29 of the suction fan 26 and communicates with the atomization section 12 . Therefore, the pressure of the sum of the negative pressures generated by the blower fan 14 and the suction fan 26 causes
The degassed kerosene is sucked and supplied to the atomizer 12.

Next, the atomizing device of this embodiment will be explained in more detail with reference to FIG. 2. In Figure 2, the first
The same symbols as in the figure are equivalents.

The dense portion 12 is fixed to the partition wall 31 with screws 32. Reference numeral 33 denotes a base body, which has a horn-shaped pressurizing chamber 34 inside. The pressurized chamber 34
A nozzle portion 36 having a plurality of small-hole nozzles 35 is fixed to the tip thereof with a screw 39 together with a spacer 37 and a presser metal fitting 38 . On the other hand, an electric vibrator 42 consisting of a diaphragm 40 and a disk-shaped piezoelectric element 41 is provided at the bottom of the pressurizing chamber 34 . Reference numeral 43 denotes a supply chamber, which is provided around the entire circumference of the electric vibrator 42 and communicates with the pressurizing chamber 34 over the entire circumference through a communication section 44 .

The deaeration section 8 includes a deaeration chamber 46 in which a second piezoelectric element 45 is provided on the outside of the front wall, and a storage chamber 47, and these two chambers are communicated through a hole 48. Kerosene is supplied from the pipe 7 as shown by the arrow to the second piezoelectric element 45.
The air is degassed by the cavitation effect caused by ultrasonic vibrations. That is, the dissolved air in the kerosene becomes bubbles 49 and is exhausted from the exhaust pipe 9, and the deaerated kerosene is sent to the storage chamber 47 through the hole 48. By separating the degassing chamber 46 and the storage chamber 47 in this manner, it is possible to prevent a portion of the undegassed kerosene from entering the degassing section 12 during the atomization operation.
Reference numerals 50 and 51 indicate liquid levels, and the deaeration of the dissolved air in the kerosene by the degassing section 8, which is controlled by the leveler 6, has the following effects.

Figure 3a shows the atomizing section 8 when obtaining a constant amount of atomization.
It shows the relationship between the operating frequency and the atomized particle size d, and shows that the higher the operating frequency, the smaller the atomized particle size d. On the other hand, Figure 3b shows the relationship between the dissolved air ratio α in kerosene and the cavitation occurrence frequency _C , and shows that under a constant driving voltage, the smaller the dissolved air ratio α, the higher the cavitation occurrence frequency _C. Therefore, it is shown that if α is made smaller by the degassing part 8, the atomizing part 12 can be driven at a high frequency, and this means that the atomized particle diameter d
This shows that it is possible to reduce the

Reference numerals 50 and 51 indicate liquid levels, which are controlled by a leveler 6 and kept at approximately constant positions as shown in the figure.
When the blower motor 13 is started, a suction force as shown by the arrow in the figure is generated in the suction pipe 30 due to the negative pressure generated by the blower fan 14 and the suction fan 26 as described above. Therefore, from the exhaust section 52 to which the suction pipe 30 is connected, there is a pressurization chamber 34 and a supply chamber 43.
The air inside is sucked out. Small hole nozzle 35 is 40~
Since the holes are about 100 μm in size, the liquid level 50 rises due to the suction force mentioned above, and the supply chamber 43 and pressurizing chamber 34 are completely filled with kerosene, and finally the liquid level 50 reaches the set position in the suction pipe. It balances out by rising to .

FIGS. 4a and 4b are diagrams illustrating the atomizing operation after the atomizing section 12 has finished filling with kerosene as described above, and the same reference numerals as in FIGS. 1 and 2 are equivalent.

Vibration plate 40 of electric vibrator 42 and piezoelectric element 41
An alternating current voltage is applied between the top surface 53 and the top surface 53 of FIG.
It is applied according to the required amount of atomization as shown in c. The piezoelectric element 41 repeats the states shown in FIG. 4a and FIG. 4b depending on the polarity of the applied voltage to perform expansion/contraction vibration in the radial direction depending on the polarity of the applied voltage. In the state shown in FIG. 4a, the pressure generated by the electric vibrator 42 is concentrated in the vicinity of the nozzle part 36 by the pressurizing chamber 34 as shown by the arrow in the figure, and is applied to the curved surface part 54 of the nozzle part 36. Figure 4a from the small hole nozzle 35
It is discharged as follows.

Next, when a voltage of opposite polarity is applied to the electric vibrator 42, the state shown in FIG. 4b occurs, and negative pressure is generated near the electric vibrator 42. Due to this negative pressure, kerosene is supplied from the supply chamber 43, and therefore the supply chamber 4
The supply chamber 43 is supplied with kerosene from the pipe 11 connected to the fuel tank 3. Therefore, the atomizing section 12 has a kerosene self-sufficiency function and does not require a liquid supply means such as a pump for supplying kerosene. At this time, some pressure drop occurs near the nozzle part 36, but the pressure drop is small because the pressurizing chamber 34 has a horn shape, and the hole diameter of the small hole nozzle 35 is small, and the pressure drop is small in the discharge direction. Since the small hole nozzle 35 is formed in a tapered shape with a decreasing diameter, strong surface tension is generated in the small hole nozzle 35, so that air does not flow in from the small hole nozzle 35.
Therefore, stable kerosene self-sufficiency can be achieved.

Further, the reason why the nozzle part 36 is provided with the curved part 54 and the small hole nozzle 35 is provided in the curved part 54 is that the nozzle part 36 resonates with the pressure waves generated by the electric vibrator 42 as described above. This is to prevent the nozzle portion 36 from vibrating, and if resonance vibration occurs in the nozzle portion 36, air will flow from the small hole nozzle 35 into the pressurizing chamber 34, making stable atomization impossible. Furthermore, by making the curved surface part 54 protrude in the direction of kerosene discharge, it acts to prevent the occurrence of resonance vibration of the nozzle part 36 described above, and at the same time, allows the atomized particles to be dispersed and discharged, so that the atomized particles are recombined. It is possible to prevent the particles from becoming large particles and to enable good mixing with air.

As shown in more detail in FIGS. 6a and 6b, the nozzle part 36 has a plurality of small hole nozzles 35 all arranged on the curved surface part 54, and each small hole nozzle 3
5 are kept at even pitch. The taper of the small hole nozzle 35 has a curved surface portion 54 as shown in FIG. 5b.
The diameter of the nozzle 35 decreases in accordance with the direction in which it protrudes, creating a difference in the flow velocity of kerosene at the inlet and outlet of the small hole nozzle 35, and the flow velocity at the outlet becomes faster. Therefore, when the electric vibrator 42 is distorted in the discharge direction as shown in FIG. 4a, the small hole nozzle 35
Droplets (atomized particles) can be discharged smoothly from
The small-hole nozzle 35 has good cutting performance, and the atomization performance can be improved. On the contrary, electric vibrator 4
2 is distorted in the direction opposite to the discharge direction as shown in FIG.
Since the taper acts to increase the surface tension in the atomizing section 12, stable self-sufficiency of the atomizing section 12 can be ensured.

The atomizing section 12 having such a configuration could be realized, for example, by the configuration described below. The nozzle part 36 is made of a stainless steel plate with a thickness of 50 μm, and the tip hole diameter is
A small hole nozzle 35 with a diameter of 80 μm was fabricated using an etching method. As described above, in order to provide a taper in the small hole nozzle 35, etching was performed from one side of the stainless steel plate using the so-called single-sided etching method. In this way, the outlet hole diameter is 80μm and the inlet hole diameter is 90~95μm.
The small hole nozzle 35 having a taper of about m could be easily realized at low cost. Furthermore, the piezoelectric element 41 forming the electric vibrator 42 has a diameter of 15 mm.
The thickness may be about 1 mm, so the structure of the atomizing section 12 is extremely compact and simple. In addition, the power consumption of the atomizing unit 12 required to atomize about 10 c.c. of kerosene per minute is only about 0.1 Watts, so the drive circuit for the electric vibrator 42 is also extremely low cost. A stable device can be realized, and unnecessary radiation can be reduced to a level that does not cause any actual damage.

As described above, according to the present invention, an atomizer is configured to fill a pressurized chamber provided in a base with liquid, vibrate the liquid using an electric vibrator, and discharge the liquid from a small hole nozzle. Since at least a part of the small hole nozzle of the nozzle part is tapered, the structure is extremely simple and compact.
Therefore, it is possible to realize a low-cost atomization device, and it is also possible to obtain an atomization device that has excellent atomization characteristics despite extremely low power consumption, and also enables stable atomization operation. Furthermore, since the power consumption is low, unnecessary radiation is also extremely small, and the atomization device can be made with low noise. Therefore, the present invention eliminates the conventional drawbacks and
It has many features and effects that meet the requirements for resource and energy conservation, and its industrial value is extremely large. Furthermore, a suction means is provided to supply negative pressure through the exhaust part provided on the base and fill the pressurized chamber with liquid, so cavitation bubbles etc. are discharged from the pressurized chamber and stable spraying is maintained. can.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the present invention applied to a hot air heater, Fig. 2 is a sectional view of the structure of the atomization device, Figs. Figures a, b
5A to 5C are driving waveform diagrams of the electric vibrator, and FIGS. 6A and 6B are an enlarged plan view and an enlarged sectional view of the nozzle part. 33... Base body, 34... Pressurizing chamber, 35... Small hole nozzle, 36... Nozzle part, 42... Electric vibrator, 54... Curved surface part, 26... Suction fan (suction means).

Claims (1)

[Scope of Claims] 1. A base body having a pressurized chamber for filling with liquid, a small hole nozzle facing the pressurized chamber, and an electric vibrator for vibrating the liquid in the pressurized chamber. , a suction means for supplying negative pressure through an exhaust part provided on the base body to fill the pressurized chamber with liquid, and at least a part of the small hole nozzle is substantially tapered. An atomization device featuring: 2. A plurality of small hole nozzles are arranged on a curved surface protruding in the liquid discharge direction, and the diameter reduction direction of the taper provided on the small hole nozzle matches the protruding direction of the curved surface. Atomization device as described in section. 3. The atomization device according to claim 1 or 2, wherein the small hole nozzle is formed by single-sided etching.