KR820000083B1 - Tranducer assembly ultrasonic atomizer and fuel burner - Google Patents

Abstract

The transducer assembly includes a first half wavelength double-dummy section (11) having a pair of quarter wavelength ultrasonic horns (12A,13) and a driving element (14) sandwiched between. A second half wavelength stepped amplifying section extends from one end of the first section and has a theoretical resonant frequency equal to the actual resonant frequency of the first section. When used as a liquid atomizer, the small dia. portion of the stepped amplifying section has a flanged tip to provide an atomizing surface of increased area. To maintain efficiency, the length of the small dia. portion of the second section with a flange should be shorter than its length without a flange.

Description

Inverter for Fuel Banana

1 is a first partial sectional view of a novel converter according to the present invention.

2 is a second partial cross-sectional view.

3 degree overall cross section.

4 is an enlarged cross-sectional view of a flanged atomized tip having a coated screen.

5 is an enlarged cross-sectional view of a flangeless screen having an oil passage installed.

FIG. 5A is a cross-sectional view taken along line 5A-5A of FIG.

6 is an enlarged cross-sectional view of the flanged atomized tip with a heating device.

7 is an enlarged cross-sectional view of a flangeless screen having a corroded surface to increase its surface area.

8 is an enlarged cross-sectional view of a flange-free screen having a concave surface.

9 is an enlarged cross-sectional view of a flange-free screen having a convex surface.

10 is a partial cross-sectional view and exemplary view of a fuel barna configured to extend the life of the ignition rod in accordance with the disclosure of the present invention.

10a is a cross sectional view of the front of the fuel bar showing the ignition rod being shrouded in sparks for a while when ignited.

10b is a cross-sectional view of the fuel bar showing that the ignition rod is separated from the flame in normal operation.

11 is a partial cross-sectional view and exemplary view of a fuel bar in which an air flow control device is installed in accordance with the teachings of the present invention.

12 is a sectional view taken along line 12-12 of FIG.

FIG. 13 is a system diagram showing a control method for the air flow rate regulating device shown in FIGS. 11 and 12. FIG.

14 is a schematic diagram of a three-stage modulation operation of an oil banana using an ultrasonic transducer.

15 is a schematic diagram of an auxiliary solar panel heating apparatus using a continuous modulation method.

The present invention relates to a converter and an apparatus for applying the converter to efficient fuel combustion. In the design of ultrasonic transducers, such as those used in fuel burners, theoretical models were used in the ultrasonic horn. The theoretical model is to use one-dimensional transformation. However, the actual operating conditions differ from the theoretical model. This difference arises from the finite dimensions of the horn-mounting method, which determines the type, ie lateral expansion or connecting means, sealing means, incorrect assembly of parts, etc., in addition to length. Introducing this difference into this model results in internal losses in the converter and thus reduces the mechanical efficiency factor Q. In the design of conventional converters, the attempt to maximize Q is to treat the whole device as a theoretical structure, select the resonance frequency of this structure, install an ultrasonic horn according to the theoretical model of the magnitude of the resonance state, and then theoretically It was to use equipment or materials of that type, such as fuel supplies, connections, seals, etc., which were arranged to minimize the inevitable losses due to differences from the model.

Prior attempts like this could not keep Q at maximum for a variety of reasons, such as: In other words, the improper design (difference from the theoretical model), the connection between the center electrode and the piezoelectric crystal of the driving element, and the ultrasonic horn portion near the piezoelectric crystal of the driving element is made due to incomplete mechanical machining of the crystal or impurities between the connecting surfaces. I didn't lose.

A second problem with converters such as those used in devices for the combustion of fuels is that the fuel delivery up to no screen is not uniform and therefore the fuel dispersion is uneven. In such past devices, it is known that fuels with low surface tensions, such as carbohydrate fuels, already begin to atomize in the passage to no screen. This early atomization creates bubbles in the fuel passage. This bubble eventually reaches the screenless, and the oil flow supplied to the screenless is temporarily suspended, making it difficult to distribute the fuel evenly. Since the bubble stays on the screen for a while, the area occupied by the bubble is not covered with fuel.

A third problem associated with converters used in combustion systems is that even if fuel is uniformly screened, the dispersion from the screen is not uniform. It is known that one of the reasons for such nonuniform dispersion lies in the bending action of the spray surface itself, which inevitably occurs in the conventional structure.

A fourth problem with conventional converters is their low efficiency. In short, in the ultrasonic fuel atomizer, the fuel film is sprayed at a low pressure without a screen and vibrates in the vertical direction at the screen without more than 20 KHz. Capillary waves are formed in the liquid film by the rapid movement of the plane. When the amplitude of the wave increases and the stability of this system is destroyed, the liquid splashes in the form of droplets in the peak phase.

The smaller the drop size, the greater the contact of fuel-air to a volume of fuel. Increasing fuel-air contact provides greater utilization of primary combustion air, thus reducing the need for excess air, which is desirable in terms of efficiency.

Further, when the constant flow rate reaches the screen-free, the thinner the film thickness, the larger surface area is used for the atomization process. This increases the atomization capacity. However, from this point of view, the conventional converter has been found to be limited because atomization occurs before the fuel supplied to the screen is completely covered. Moreover, the surface tension associated with smooth metal-free screens makes it difficult to spread throughout.

It is an object of the present invention to provide an improved reliable and high force and Q inverter that can be used in an apparatus for efficient fuel combustion.

Another object is to improve the design of such a device.

Its purpose is to eliminate premature atomization in the fuel passage to the screenless surface of the ultrasonic fuel atomizer.

Another object is to provide uniform atomization from the entire screen of the ultrasonic fuel atomizer.

Another aim is to distribute the fuel evenly and evenly over the entire screen.

Another object is to provide an improved fuel vane having an ignition rod with an extended lifetime.

Another object is to provide an air mass control device in the fuel bar or in the fuel.

Hereinafter, features and objects of the present invention will be described in detail with reference to the accompanying drawings.

One feature of the present invention is that it optimizes the shape of the converter in order to keep Q at maximum. The design of the converter according to one aspect of the invention has a first part comprising a drive element and two identical horns (FIG. 1) as shown in the drawing so that this structure is geometrically symmetric about the longitudinal axis. This structure is designed to keep the value of Q to the maximum. This first part is called a double-dummy ultrasonic horn. In the next operation, the resonance frequency of the first part is measured and the second part (figure 2) is applied, which includes an amplification step and no screen, and the resonance frequency is in line with the experimentally measured frequency of the first part. There are four complete converters (Figure 3).

In FIG. 1 the first part 11 of this new converter is a drive element 14 and a terminal (12A) and a rear (13) ultrasonic horn, which consist of a pair of piezoelectric plates (15) (16). 18) Electrodes operated by high frequency electric energy supplied from 18 are installed between them.

The drive element 14 is located between the flange portions 19 and 20 of the horn portions 12A and 13 by means of fastening elements comprising a mounting ring 21 (for attaching the device to another device). It is fixed and several bolts 22 are fitted into the screw holes of the mounting ring 21 through the terminals 18 and the flange portions 19 and 20. The bolt 22 is electrically insulated from the terminal 18 by the insulating material 23.

The first part 11 also includes sealing gaskets 26 and 27 which are press-fitted between the fuel pipe 24 and the flange portions 19 and 20 for introducing fuel into the passage in the converter.

In a typical practical structure, the horn portions 12A, 13 and the flange portions 19, 20 are made of aluminum, titanium or magnesium or a Ti-6Al-4V titanium-aluminum alloy, a 6061-T6 aluminum alloy, a 7025 high-strength aluminum alloy, It is recommended to use materials with good acoustic conductivity, such as Az61 magnesium alloy. The boards 15 and 16 are made of lead-zirconia-titanium manufactured by Vernitron and lithium myo bait made from Valeksa, and copper is used for the electrodes. The terminal 18, the mounting ring 21, and the bolt 22 Steel is used, and the material of the insulating material 23 is an electric insulating material such as nylon, teflon or plastic, and the sealing gaskets 26 and 27 are made of silicon rubber or the like.

The first part 11 has a half-wavelength symmetrical geometric shape and at the same time includes all the elements required for the converter, such as fasteners, coins, screws and mountings in non-nodal planes. Doing. The characteristics of this first part are determined and the characteristic frequency for maximum Q is quantitatively measured. In this way, the first stage design of the inverter is completed.

In figure 2 another half-wavelength part 29 is added to the first part 11. This part 29 has a large diameter part 12B and a small diameter part 30, and the amplification part 31, the flange tip part 32 which has the screenless 33, and the central cylinder which supplies fuel to the screenless 33 are shown. The furnace 34, the sleeve 35 inserted in the inner surface, etc. are comprised. The sleeve is made of a material close to Teflon, which is not sonically connected to the fuel hole.

Anyone with expertise in this field will note that this part has a nearly pure theoretical structure, so there are few unnecessary devices. The characteristic frequency for the maximum Q is calculated and selected to fit the first part 11.

The combination of these two parts 11 and 29 completes the design of the converter (Fig. 3) for efficient combustion of the fuel optimized for maximum Q.

Conventional converters for ultrasonic atomization of fuels have used the flange tip 32 having a screenless surface 33. Since the area of the non-screen is increased by the flange tip having the non-screen 33, the atomization capability is increased.

The addition of these flanges reduces the efficiency of the atomizer.

In FIG. 2, let the length of the front end portion 12B be A, and the length of the small diameter part 30 be the thickness of the B flange end 32. In a conventional converter that does not use a flange, A / B = 1, i.e., both have a 1/4 wavelength length. In a conventional apparatus using a flange, A / B + C = 1. Even when additional flanges are used, it is known that maintaining the ratio at 1 decreases efficiency and reduces power transmission, but maintaining A / B + C> 1 maintains the efficiency at the level before the use of flanges. therefore

D ₃ = diameter of flange 32, D ₂ = diameter of small diameter portion, and D ₃ / D ₂ = 1.53

A / B + C (without flange) = A / B = 1 and

A / B + C (with flange) = 1.12

The efficiency without flange is compared with the efficiency without flange.

The previous analysis assumes that their sound propagation rates are the same for devices composed of aluminum, titanium, magnesium or other alloys mentioned above. If materials with different sonic propagation rates are used, the value of A / B + C will be different, but always greater than 1.

The use of the sealing plate 15 prevents fuel contamination, thus extending the life of the device. The sealing gaskets 26 and 27 made of silicone rubber are inserted between the fastening flange portions 19 and 20. Conventionally, fuel penetrates the plates 15 and 16, worsening performance and often shortening the lifespan. This phenomenon caused the loss of the mechanical connection between the horn elements. This problem is solved by the gaskets 26 and 27 and the atomizer performance is not affected by the mass increase, which is confirmed by the before and after measurement of the impedance operating frequency and the flange displacement. The weighting of the internal temperature by the sealing disk 15 does not shorten the useful life of the atomizer because it is still below the maximum operating temperature of the piezoelectric crystal. The gaskets 26 and 27 are made of compressible material and their inner circumference is slightly larger than the outer periphery of the plates 15 and 16. When the gaskets 26 and 27 are fastened, their inner circumference is in light contact with the outer circumference of the plates 15 and 16.

Another feature of the present invention is that it prevents premature atomization in the passage before fuel reaches the screen. As mentioned above, in the past, fuel was often atomized early in the passage. This early atomization creates droplets by forming cavities in the fuel passage. If the droplets interfere with the movement of the fuel, and if the droplets reach the zero screen, disturbing the fuel supply to the portions, uniform fuel distribution becomes difficult. The droplet stays invisible for a while, so the area is not covered with fuel. The result is unstable spraying of the fuel and thus unstable combustion.

This problem is solved by installing a sleeve 35 in the fuel passage 34 that extends about 1/32 inch out of the screenless 33. This sleeve is usually made of plastic and is inserted into the passage 34 to extend into the large diameter portion 12B. Due to the difference in sound wave propagation characteristics of the material of the sleeve 35 and the horn 29, the vibrating motion of the horn 29 is not transmitted to the fuel in the passage 34 wrapped in the sleeve 35.

Another characteristic of the present invention is that uniform atomization can occur on the screen of the ultrasonic fuel atomizer. One of the causes of the nonuniformity of the atomization is that the atomizer tip bends during vibration, and it is known that the nonuniform distribution decreases when the flan surface or the screenless 33 moves as a rigid plane. By increasing the thickness of the flange tip portion 32 to allow the tip portion 32 and the surface 33 to act as a rigid body during vibration, non-uniform distribution can be prevented. In a representative practical example, the thickness of the tip portion 32 is about 0.05 inches.

Another feature of the present invention is an increase in atomization capacity. As mentioned above, it is known that the conventional converter has atomization before the fuel is completely covered on the screen. Moreover, the smooth metal surface makes it difficult to spread on the entire surface due to surface tension.

This conventional problem is solved by the present invention. In other words, by reducing the surface tension in the fuel-free screen, it is easier to flow when the fuel is supplied to the screen-free and to install a device that distributes the fuel evenly.

In FIG. 4 according to an embodiment of the present invention, the surface tension is reduced by coating the non-screen with a material that reduces the surface tension. 4 shows the flange tip 32 having a flat screen 33 coated with a thin coating. Examples of such materials include teflon, polyvinylchloride, polyesters and polycarbonates.

Another embodiment of the present invention, in conjunction with the fifth diagram, is that the flow capacity of fuel is increased by passages or grooves 42 provided in the screenless 33. By installing the grooves 42 extending through the outer periphery of the flange tip, fuel is spread over the entire screen. Therefore, instead of forming a thick fuel film near the central fuel passage, a thin fuel film is formed on the entire surface.

Another embodiment of the present invention in Figure 6 is that the heating device 43 is provided so as to raise the temperature of the non-screen up to about 150 ℃ during operation. Heating reduces the viscosity of the fuel and thus facilitates distribution throughout the screen.

Another embodiment of the present invention is shown in FIG. 7 that the surface of the non-screen is corroded by sand blasting or the like to increase the surface area and reduce the thickness of the film for a certain amount of fuel.

Depending on the geometric appearance of the flangeless surface, the density of the particles formed by the spray pattern and atomization changes. Thus, for example, the planar flat screen 33 shown in FIGS. 2-7 forms a constant pattern and density. If the surface is concave, as shown in (33 ') in Fig. 8, the spray pattern is wider, and the number of particles per unit area of the cross section is smaller than that of the flat surface. In the case of the block face 33 "like the ninth degree, the spray pattern is narrowed and thus the particle density is increased. Different spray patterns may be required depending on the application.

Now, when we shift our attention from the inverter to the fuel burner, the problem is that the ignition rod life is short. The spark rods discharge sparks to ignite the fuel air mixture. Once ignition occurs, the ignition rod will be encased in flames and will always be in contact with high temperatures, so the ignition rod will deteriorate and should be replaced frequently.

One problem of the present invention solves the above problem. That is, while ignition rods are positioned so that they are not exposed to conventional flames, the power supplied to the ignition rods during ignition is increased. This increases the spray angle, which, when ignited, causes the ignition rod to contact the spray zone of the air fuel mixture to form a spark. As soon as the ignition occurs, the spray angle is reduced by reducing power, thus returning to the normal flame angle, so the ignition rod is located outside the normal flame.

Referring to FIG. 10, the fuel burner 50 has an air supply blower 54 for igniter combustion and cooling of the changer 52 including the vent pipe 51, the converter 52, and the ignition rod 53. , Air flow direction adjusting device 55, flame passage 56, power supply adjusting device 57, flame detector 58 and pump device 59 for supplying fuel from the fuel tank 60 to the changing device, etc. It consists of. The ignition rod 53 is fixed between the vent pipe 51 and the flame passage 56 by a ceramic or magnetic insulating material surrounded by a high temperature asbestos material. Two inches apart is enough distance. During ignition, additional power is supplied from the power source 57 to the inverter input line (higher voltage and current supplied than during normal operation). This can be accomplished automatically by flowing excessive power into the inverter input circuit by power supply computational programming prior to firing. At the time of ignition, the ignition rod is positioned in the flame formed in the flame passage (FIG. 10A). Once the ignition occurs, a signal is transmitted to the power supply by the flame detector 58 to lower the normal power, so that the ignition rod 53 is out of the flame (FIG. 10b). Long life because it is kept at a low temperature. The ignition rod is not subjected to deterioration or oxidation due to continuous heating.

The advantage of ultrasonic fuel atomizers is that they can vary the fuel flow rate extensively. However, such a fuel flow amount requires a device capable of changing the amount of combustion air supplied through the burner combustion tube 51 for a wide range of changes. This problem is solved by using an electrically controlled change in the air port porter speed or by using a variable opening orifice which is positioned in the air passage while keeping the motor speed constant. The latter case is more preferred, as shown in FIGS. 11-13, since a certain amount of static pressure is required to cause turbulence required for efficient combustion. This is solved with an iris type diaphragm 61 (11 and 12 degrees) in an electrically controlled combustion tube as shown in FIG.

The control of the diaphragm 61 is made electrically. Depending on the fuel flow rate, the amount of air required for optimum combustion is automatically adjusted by opening and closing the diaphragm until the optimum combustion condition is detected. Optimum combustion conditions are sikimeuroseo back feedback the measurement data from the sensor is detected by measuring the CO ₂ content in the combustion gas in the 62 from the furnace to the dwelling air adjustment circuit for less-type diaphragm (61), (63) CO ₂ The content is adjusted to a predetermined level such as 12.5-13%.

Conventional oil burners have been operated at constant fuel flow in two stages of operation and shutdown. These two phases of operation have several drawbacks. First, it consumes more fuel than it needs, which is uneconomical and causes pollution problems. This two stage mode of operation involves a large amount of unburned hydrocarbons or carbon monoxide when moving from stop to operation or vice versa.

This conventional problem is solved by the three-step format according to the present invention. In FIG. 14, the three-stage type means three different combustion rates: high combustion, low combustion, and stopping. For example, three burn rates can typically be expressed as:

High combustion: 0.6 gallons / hour

Low combustion: 0.2 gallons / hour

Stop: 0.00 gallons / hour.

The high combustion is made according to the duct or the chimney-type thermostat 71 which responds to the thermal efficiency detection as in the conventional heating apparatus having the conventional thermostat. Once the heat requirement is met (as determined by the thermostat setting), the control unit 73 is returned to low combustion via an adjustment valve 72 to maintain the duct and heat exchanger temperature of the device at an elevated temperature. This prevents exhaust losses that occur when stopped completely, such as in a heater.

The operating cycle is, for example, 10 minutes of high combustion, 20 minutes of low combustion, and then 10 minutes of high combustion. The period of high or low combustion is determined by the heat required. By using this method of operation, the efficiency of the furnace is increased because the furnace is already heated at the start of high combustion. Moreover, since all the heating devices are already at a somewhat high temperature at low combustion, even if high temperature combustion is required, no large load is required as in the prior art.

For a three-stage mode of operation, the stop is only used if the required heat load is zero, such as when the weather outside is at or above room temperature. This can be done by connecting the external temperature sensing device 74 to this device or can be done manually.

According to another feature of the invention, the converter according to the invention can also be used in oil-fired furnace systems employing continuous modulation. As shown in FIG. 15, the combustion rate of the system can be continuously changed in response to an external control signal supplied to the burner computer as in the case of using the auxiliary solar panel heating device within a certain upper and lower range. When the temperature of the hot water tank 81 is maintained above the minimum To, when the variable solar energy transmitted through the pump 82 and the solar plate 83 is insufficient, an appropriate amount of heat is required from the oil burner 84. Shall be. This deficit is always changing and is detected at 85 to cause the oil banana 84 to generate heat within the design limits of the device as needed, to the required level of energy from the sun and oil banana. To be maintained.

In the above description of the features of the present invention has been described for the oil fuel banana suitable for home heating, it is obvious that it can be used for other uses. For example, it can be used for low-flow vana for mobile homes that require less than half a gallon per hour, and the ability to control the flow rate is a major economic advantage. The present invention can also be used to supply fuel to internal combustion engines or jet engines. The invention can also be used for atomizing other liquids such as water. The present specification has been described with reference to specific embodiments for better understanding of the present invention, but it will be apparent to those skilled in the art that the present invention is not limited to such specific embodiments and various modifications are possible.

Claims (1)

Amplification in which the first part 11 having a characteristic resonance frequency and the theoretical resonance frequency coincide with the characteristic resonance frequency of the first part, comprising a driving element 14 and a double-body ultrasonic horn 12, 13 disposed between the horns. Converter comprising a second part (29) comprising a part (31).

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