JPS6050504B2 - atomization device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for atomizing liquid fuel such as kerosene and light oil, water, and chemical solutions. The object of the present invention is to provide an atomization device that is easy to control.

Various types of liquid atomization devices have been proposed and put into practical use, including a pressure atomization device that pumps and pumps a liquid at high pressure and sprays it at high pressure from a small hole nozzle, and a pressure atomization device that pumps a liquid at high pressure and sprays it at high pressure from a small hole nozzle. 3) A two-fluid atomizer that ejects high-pressure liquid and high-pressure gas and generates vibrations using a resonance structure to atomize the atomization; A width-enhancing ultrasonic atomizer that increases the amplitude and supplies liquid to the increased vibration part to atomize it;
5 Cavitation-type atomizers that irradiate ultrasonic energy into a liquid tank and atomize the liquid by utilizing cavitation near the liquid surface are in practical use or are under consideration for practical use.

However, both pressure atomizers and two-fluid atomizers require high pressure to be applied to the liquid, which requires a high-pressure pump, which increases the size of the entire device and causes problems such as noise generation. Atomization performance (atomization particle size, distribution, etc.) was also not sufficient.

Rotary atomizers also require a high-speed rotary body, resulting in large-sized devices, high noise, and poor atomization performance. In addition, with the ultrasonic atomizer of the width-increasing width type, it is difficult to process and fix the horn for efficient width-increasing, resulting in high prices and poor atomization performance. . Furthermore, the above-mentioned rotary atomizer and amplitude-enhancing ultrasonic atomizer require pumps and the like for supplying liquid and determining the amount of atomization, making them even more expensive. Cavitation-type atomizers exhibit excellent characteristics in terms of atomization performance, but they require emitting ultrasonic energy directly into the liquid tank and effectively concentrating the energy near the liquid surface, making atomization difficult. The operation is unstable, and the structure for compensating for it is troublesome, and the optimum operating frequency for atomization is between 1 and 2 MHz, so there is a risk of radio wave interference.

Furthermore, the large amount of energy required for atomization further increases the risk of radio wave interference and requires an expensive drive device. The present invention has been made in view of these points, and provides an atomization device that has a simple and compact configuration, is therefore inexpensive, has excellent atomization performance, and is extremely easy to control the amount of atomization. This is what I am trying to do.

Although the present invention should not be limited to one application, an embodiment in which the present invention is applied to a liquid fuel atomization device and constitutes a hot air heater will be described with reference to the drawings.

FIG. 1 is a sectional view showing the configuration of a hot air heater.

In the figure, 1 is a case of a hot air blower, and liquid fuel 2 such as kerosene is supplied from a cartridge tank 3, passes through a supply vibrator 6 from a leveler 5 where the liquid level 4 is maintained substantially constant, and returns to a return section 7. A supply chamber 11 provided in the base body 10 via a pump 8 serving as a liquid supply means and a supply section 9
, so as to fill the pressurizing chamber 12. When the hot air fan stops operating, the liquid level 13 and the liquid level 14 are located at the same level as the liquid level 4 of the leveler 5, and the state is as shown in the figure. The return section 7 also serves as a liquid heating chamber! It is equipped with a heater 15 having a positive characteristic, is covered with a heat insulating material 16, and is thermally isolated from the supply vibe 6, return vibe 18, etc. by a heat insulating part 17.

A portion of the supply vibrator 6 and the vibrator connecting between the pump 8 and the return section 7 form a heat exchange section 19, and the liquid fuel supplied from the leveler 5 to the heating chamber and the return section 7 The heater 15 is configured to exchange heat with the liquid fuel supplied to the pump 8, thereby reducing the power consumption of the heater 15. The return section 7 functions to temporarily raise the temperature of the liquid fuel to a high temperature in order to discharge air dissolved in the liquid fuel, and has an opening 20.

From this opening 20, some vaporized gas (liquid fuel) may be generated since the return section 7 becomes high temperature.
In that case, the opening 20 may be configured to exhaust into the combustion tube 21 or the exhaust section 22, or directly to the outdoors. On the other hand, combustion air is sucked in by a combustion fan 24 from the suction port 23 and sent to the combustion tube 21 through air passages 25 and 26 as indicated by the arrows in the figure.

The liquid fuel supply section 9 is configured to cross the air passages 25, 26, so that the liquid fuel can be effectively cooled. Next, the operation of the hot air fan will be explained, focusing on the atomization device.

In response to a command from the operating section 27, the combustion control section 28 energizes the heater 15, and at the same time or after some time, starts the rear pump 8. The pump has a pumping capacity equal to or larger than the maximum atomization amount, and is configured so as not to interfere with normal atomization operation. As the pump 8 operates, the liquid level 14 of the liquid fuel 2 is pushed up, and the liquid fuel 2 is supplied to the base 10 and then to the supply chamber 11 .
The pressurizing chamber 12 includes a horn-shaped part formed in the base body 10 and a plurality of small hole nozzles (30
The supply chamber 11 is composed of a nozzle portion 30 having a diameter of about 100 μm (p7n to 100 μm) 29, and an electric vibrator 33 provided at the bottom of the horn-shaped portion and consisting of a diaphragm 31 and a piezo vibrator 32. Communication is provided by a communication portion 34 formed over the entire outer circumference of the electric vibrator. Therefore, the liquid fuel supplied to the supply chamber 11 fills the pressurizing chamber 12 as well as the supply chamber 11, overflows from the return vibe 18, and returns to the return section 7.
In this state, the liquid fuel does not overflow from the small hole nozzle 29 provided in the nozzle part 30 due to the surface tension of the liquid fuel, and therefore the liquid fuel is transferred from the return part 7 to the pump by the pump 8. 8 → Supply chamber 11 → Pressure chamber 12
→ return vibe 18 → return part 7. That is, after being heated in the heating chamber 7 and discharging the dissolved air in a high temperature state, it is cooled by the heat exchange section 19 and the cooling section extending into the air channels 25 and 26 of the supply section 9, so that the amount of dissolved air decreases. In this state, the supply chamber 11 and pressurization chamber 12 are filled with liquid fuel. As is clear from the above description, the purpose of heating by the heater 15 is to discharge air dissolved in the liquid fuel, and this does not necessarily have to be heating.

For example, an ultrasonic vibrator may be used instead of the heater 15, and dissolved air may be discharged using cavitation caused by the ultrasonic vibrator. That is, it is important to provide a means (deaeration means) for discharging dissolved air into the above-mentioned circular path by the pump 8. The combustion fan 24 is activated at the same time as or later than the activation of the pump 8, and the ignition means 35 is activated later than that. The ignition means 35 consists of an ignition electrode, and the combustion control section 2
8. Next, the oscillator drive section 36 in the combustion control section 28 is connected to the main control section (also serving as an atomization control section) 46.
AC voltage is applied to the electric vibrator 33.

Since the piezo element 32 constituting the electric vibrator 33 expands and contracts in the radial direction depending on the polarity of the AC voltage, the electric vibrator 33 generates a drum-like vibration in the direction of the nozzle portion 30. The electric vibrator 33 is deflected in the direction of the nozzle part 33, and a pressure rise occurs in the vicinity thereof, and this pressure rise is amplified by the horn-shaped pressurizing chamber 12 and reaches the nozzle part 30. Therefore, liquid fuel is discharged from the small hole nozzle 29 provided in the nozzle section 30. Next, when the electric vibrator 33 deflects in the opposite direction to that described above due to a change in the polarity of the applied voltage, a pressure drop occurs in the vicinity thereof. This pressure drop is caused by the fluid diode-like action of the horn-shaped pressurizing chamber 12 having a portion whose cross-sectional area does not change in the discharge direction as shown in the figure, and the communication portion 34 provided around the entire circumference of the electric vibrator 33. Due to the inflow of liquid fuel from the nozzle 29, a large pressure drop does not occur in the vicinity of the nozzle portion 33, and therefore the surface tension of the liquid fuel generated in the nozzle 29 is not broken. That is, even in this state, the small hole nozzle 2
There is no inflow of air from 9, and therefore the action of a pump can be exerted. Since the dissolved air in the liquid fuel is reduced by the degassing means consisting of the return section 7, it is possible to repeat this operation at a high frequency of about 10K pressure to 100KHz. , extremely atomized liquid fuel is sprayed and ignited by the ignition means 35 to form a flame 37;
When ignition is detected by the flame rod 38, the ignition operation by the ignition means 35 is stopped.

Since the amount of atomization, that is, the amount of combustion, is determined by the operation of the electric vibrator 33, an extremely simple pump 8 with low precision is sufficient.
It may be a supply means that utilizes the blowing pressure of the blower, or it may be of a type that mechanically transmits the rotational force of the blower fan 24.

In short, any material may be used as long as it has a pumping capacity equal to or greater than the maximum amount of atomization so as to prevent air from entering the pressurizing chamber 12 or the supply chamber 11 during the atomizing operation. At the start of the atomization operation (ie, during the ignition operation) as described above, the electric vibrator 33 is controlled by the combustion control unit 28 to operate at a frequency lower than the normal operating frequency.

This is because even if the pressurizing chamber 12 is filled with liquid fuel by the pump 8, foreign matter such as very small air bubbles may be inside the pressurizing chamber 12.
This is to ensure normal startup even in such a situation. In other words, the fixed time at startup or the time until ignition is detected is somewhat inconvenient (for example, the particle size becomes somewhat larger, or the audible frequency tends to generate a harsh sound).
Even if a
100KHz). By doing so, it becomes possible to start the atomization operation 7 stably and reliably.

Further, the electric vibrator 33 has a diameter of 10 to 20Tf0n.
Since the hot air fan to which the present invention is applied has a small and compact structure, the structure of the hot air fan to which the present invention is applied can be made extremely small and compact. At the same time, the particle size of the atomized particles discharged is small, and it is possible to burn them directly as shown in the figure. When used in a combustion machine, there is no need for a vaporizer, etc., and there is no reduction in combustion performance. Simplified ratios of combustor configurations are possible.

FIG. 2 is a control circuit diagram of a hot air fan showing an embodiment of the present invention, and power is supplied from commercial power terminals 40 and 41. FIG.

Reference numeral 42 denotes an operation switch provided in the operation section 27, and when this is turned on, the combustion control section 28 is energized. As described above, the combustion control unit 28 controls the combustion fan 2 via the electric vibrator 33, the heater 15, and the relay contacts 43 and 44.
4, a pump 8 linked thereto, and an ignition means 35
control. A thermoswitch 45 controls the blower fan 39 for exchanging heat between the combustion tube (heat exchanger) 21 and indoor air.

FIG. 3 is a circuit diagram showing a more detailed embodiment of the combustion control section 28, which is composed of an oscillator drive section 36 and a main control section 46. The main control section 46 is composed of a power supply section consisting of a power transformer 47 and a rectifier 48, and a microcomputer 49 that plays a central role in control functions. , 51, 52, a flame detection signal from an ignition detection circuit consisting of a capacitor 53 and a field effect transistor (FET) 54, a thermistor 55 that detects the temperature of the load such as room temperature, a temperature setting device 56, resistors 57, 58, 59, a temperature detection signal from a room temperature detection (load temperature detection) circuit consisting of a comparator 60, etc., and according to a program determined by these input signals and a timer using a built-in counter, the relay 61 ~64. The contacts of the relays 61 and 62 are contact 4 in FIG.
The relays 63 and 64 control the opening and closing of contacts 65 and 66a and 66b of the vibrator drive section 36, respectively. The vibrator drive unit 36 includes an operational amplifier 67 and resistors 68 to
74, an oscillator consisting of capacitors 75, 76, diodes 77, 78, transistors 79 to 81, and resistor 82
86 and a power amplifier consisting of capacitors 87 to 89.

The oscillator is a so-called Wien bridge oscillator, and its oscillation frequency can be adjusted as shown in FIG. It changes like A and b. That is, as described above, the microcomputer 49 controls the relay 63 to turn off so that it starts at a low frequency and stably starts the atomization operation, and turns on the electric vibrator 33 for a certain period of time. A voltage as shown in FIG. 4b is supplied to .

At this time, in order to reduce the resistance value of the resistor 86 and increase the voltage level, if necessary, add another one to the relay 63.
You can also add contacts. The relay 64 controls the amount of atomization by opening and closing its contacts 65, and the microcomputer 49 controls the opening and closing duty of the contacts 65 of the relay 64, controls the average amount of atomization, and stops the atomization. At this time, the relay contact 65 is opened to stop atomization.

The opening/closing duty is performed at a short cycle that does not adversely affect combustion, and if a shorter cycle is required and the relay 64 cannot follow it, a semiconductor switch such as a photocoupler may be used. It's okay.

FIG. 5 shows the driving frequency f1 voltage ■ of the vibrator 33 during startup with time t, and a
is the case of this embodiment circuit, and b is another embodiment in which V is also varied.

Further, in the embodiment shown in FIG. 5, the switching of f or ■ is carried out rapidly, but if necessary, it is also possible to switch f or V gradually using a time constant circuit. .

As described above, according to the present invention, there is provided a base body provided with a pressurized chamber filled with liquid, an electric vibrator that vibrates the liquid in the pressurized chamber, and a vibrator that energizes the electric vibrator. A drive unit and an atomization control unit, wherein at least one of the frequency or voltage of the AC voltage supplied to the electric vibrator at the time of starting atomization is different from the frequency or voltage during normal atomization operation. Since the atomization controller is configured to control the value, the configuration is extremely simple and compact, resulting in low cost, excellent atomization efficiency and performance, and stable and reliable startup. It is possible to provide an atomization device that is capable of

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the configuration of a hot air heater to which an embodiment of the present invention is applied, FIG. 2 is a control circuit diagram of the hot air heater, FIG. 3 is a circuit diagram of the combustion control section of the control circuit, and FIG. FIG. 4 is a vibrator drive waveform diagram, and FIG. 5 is an explanatory diagram of the vibrator drive voltage and frequency at the start of the atomization operation. 10... Base body, 12... Pressure chamber, 29.
... Small hole nozzle, 33 ... Electric vibrator, 36 ... Vibrator drive section, 46 ... Main control section (atomization control section).

Claims (1)

[Scope of Claims] 1. A base body having a pressurized chamber for filling a liquid, one or more small hole nozzles provided facing the pressurized chamber, and a base body having a pressurized chamber for filling the pressurized chamber with the liquid in the pressurized chamber. an electric vibrator for vibrating; a vibrator drive unit that supplies an alternating voltage to the electric vibrator; An atomization device comprising an atomization control section that controls frequency or voltage to a different value. 2. Claim 1, characterized in that the atomization control section controls the vibrator drive section so that the alternating power frequency at the start of atomization is lower than the frequency during normal atomization operation.
Atomization device as described in section. 3. Claim 1, characterized in that the atomization control section controls the vibrator drive section so that the voltage of the alternating power at the time of starting atomization is higher than the voltage during normal atomization operation. Atomization device. 4. The atomization control section controls the vibrator drive section so that the alternating power at the start of atomization has a lower frequency and higher voltage than the alternating power at the time of normal atomization operation. An atomizing device according to claim 1.