US3796536A - Liquid fuel burner - Google Patents

Liquid fuel burner Download PDF

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Publication number
US3796536A
US3796536A US00246848A US3796536DA US3796536A US 3796536 A US3796536 A US 3796536A US 00246848 A US00246848 A US 00246848A US 3796536D A US3796536D A US 3796536DA US 3796536 A US3796536 A US 3796536A
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US
United States
Prior art keywords
horn
liquid fuel
fuel burner
set forth
mixing vane
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00246848A
Other languages
English (en)
Inventor
M Hori
N Rokudo
T Ishiguro
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP3347071U external-priority patent/JPS4729827U/ja
Priority claimed from JP5822571U external-priority patent/JPS4815826U/ja
Priority claimed from JP9082171A external-priority patent/JPS52266B2/ja
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Application granted granted Critical
Publication of US3796536A publication Critical patent/US3796536A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D11/00—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space
    • F23D11/34—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space by ultrasonic means or other kinds of vibrations
    • F23D11/345—Burners using a direct spraying action of liquid droplets or vaporised liquid into the combustion space by ultrasonic means or other kinds of vibrations with vibrating atomiser surfaces
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S239/00—Fluid sprinkling, spraying, and diffusing
    • Y10S239/19—Nozzle materials

Definitions

  • ABSTRACT A liquid fuel burner is provided which has a fuel atomizing surface or portion formed at the free end of an exponential horn whose base is securely fixed to a vibrator coupled to an ultrasonic wave generator and which is'so mounted that its vibrations may not be transmitted to an outer duct or housing enclosing the horn.
  • An inner mixing vane assembly is disposed coaxially and outwardly of the fuel atomizing surface of the horn in spaced apart relation therewith, and an outer mixing vane assembly is also disposed coaxially and outwardly of the inner mixing vane assembly.
  • the present invention relates to generally a liquid fuel burnenand more particularly a liquid fuel burner utilizing an ultrasonic wave in order to atomize fue oils.
  • the fuel oil forms a very thin film upon the vibrating surface having a certain area ahd vibrating at an ultrasonic frequency so that the fuel 'oil may be atomized into finely divided particles under the ultrasonic vibrations of the oscillating surface.
  • the prior art liquid fuel burners utilizing ultrasonic wave generators have acommon defect in that the kinetic energies of the atomized fuel particles are less than those of the fuel particles atomized under the pressure of airflow or the like, so that the atomized fuel particles are not uniformly distributed.
  • the atomized fuel particles start to drop by gravity immediately after they are discharged from the vibrating surface, they form an excessively densely concentrated combustion or air-fuel mixture zone in the proximity of the vibrating surface. Therefore, not only does the ignition of such densely concentrated air-fuel mixture become difficult, but also. the pulsation in combustion and jumping of flames occur because the percentage of air 4 in the air-fuel mixture is small. As a result, the combustion efficiency is substantially reduced whereas the combustion noise is increased. Furthermore, since the atomized fuel particles have less kinetic energies they are easily susceptible to the combustion air flow, so that they tend to be spread out of the combustion zone into the poor combustion zone. Thus a considerable amount of atomized fuel particles are wasted.
  • the input to the ultrasonic wave generator must be increased. Further, when input power greater than the rated power is used, heat dissipation is increased, thus resulting in shorter service life of the fuel burner. Moreover, in case of the liquid fuel burners utilizing the ultrasonic wave generators, the vibrations of the vibrator are transmitted to other associated component parts, so that a substantial increase in noise is produced.
  • One of the objects of the present invention is therefore-to provide a liquid fuel burner utilizing an ultrasonic wave for atomizing fuel oils the burner being characterized by high combustion efficiency.
  • Another object of the present invention is to provide a liquid fuel burner which produces less combustion noise.
  • Another object. of the present invention is to provide a liquid fuel burner which produces less mechanical vibrations due to the ultrasonic vibrations.
  • Another object of the present invention is to provide a liquid fuel burner with high fuel oil atomization efficiency.
  • the atomized fuel particles which are carried by the streamlined or straightened air flow are enclosed by two whirling air flows so that the atomized fuel particles which tend to spread away from the cumbustion zone may be converged toward the combustion zone.
  • theexponential horn and hence the atomizing portion are supported in such a manner that the transmission of the vibrations of the horn to the other component parts may be minimized.
  • the materials for the atomizing portion are selected in order to attain the highest atomization efiiciency.
  • FIG. 1 is a longitudinal sectional view of onepreferred embodiment of the present invention taken alongthe line I-IOF FIG. 2;
  • FIG. 2 is an end view thereof looking to the left side thereof;
  • FIG. 3 is a front view, partly in section, of anexponential horn thereof illustrating the detail thereof;
  • FIG. 4 is an end view thereof looking to the right end thereof; I
  • FIGS. 5-7 are graphs used .for explanation of the advantages of the liquid fuel burner in accordance with the present invention.
  • FIGS. 8 and 9 are a side view and an end view illustrating two variations of the method for mounting the exponential 'hom of the fuel burner in accordance with the present invention.
  • an exponential horn 1 has its base fixed to a magnetostrictive vibrator 2 which in turn is electrically coupled through leads 3 to an ultrasonic wave oscillator 4. Therefore, the horn l'vibrates at an ultrasonic wave frequency as the magnetostrictive generator 2 oscillates.
  • An outer cylindrical duct or housing 5 is disposed coaxially of the exponential horn 1 and has its left end fixed to an annular end member 6 having a diverging or tapered-portion 6a, an arcuate wall portion 6b and a radially extending flange portion 6'c.
  • the exponential horn l is securely supported in the outer duct or housing 5 by a plurality of bracketslO as will be described in more detail hereinafter.
  • Ignition plugs 12 which are disposed in the outer duct or housing 5 and have spark discharge electrodes 13 extend through the outer mixing vane assembly 8 and are electrically coupled to a transformer 14 through high tension lines 1 1.
  • a fuel oil regulator 16 is hydraulically communicated through a fuel line 15 with a fuel injection port 17 formed at the center of the horn 1 so that the fuel oil is supplied to an atomizing surface 18 at the left end of the horn 1 through the reg ulator 16, the fuel line 15 and the fuel injection port 17.
  • FIG. 3 the portion marked by A in FIG.1 is shown in detail.
  • the horn 1 which is vibrated by the magnetostrictive vibrator 2 has the nodes along its axis at which the amplitudes are zero so that the fuel line 15 is so located as to extend radially into the horn 1 at the nodal position to communicate with the fuel injection port 17.
  • the horn l is also supported at the nodal position. That is, a plurality of arms 22 having holes 22a.
  • brackets 10 and the arms 22 are spaced apart from each other by the vibration isolators 19.
  • the bases of the brackets l' may be securely fixed to the inner wall of the outer duct or housing for example by welding.
  • the vibrations of the horn 1 are transmitted to the arms, but since the vibration isolators 19 are interposed between the arms 22 and brackets 10, the transmission of vibrations from the horn 1 to the outer duct or housing 5 can be sub.- stantially reduced as shown in FIGS.
  • the solid line curve 0 illustrates the relation between the sound pressure and the frequency when no vibration isolators are used
  • the dashed curve b the relation when the vibration isolators 19 are used. It will be seen that according to the present invention the sound pressure can be reduced almost about one fourth as compared with the burners using no vibration isolators.
  • the induced air flows in the directions indicated by the arrows P, Q and R. That is, the air flows along the peripheral surface of the horn 1 and through the horn l and the inner mixing vane assembly 9 as indicated by.
  • the air also flows through the inner mixing vane assembly 9 as indicated by the arrow Q and through openings 7a of the inner duct 7 and the outer mixing vane assembly 8 as indicated by the arrow R.
  • the induced air mixes with the fuel oil atomized at the atomizing surface 18, and the air-fuel mixture or combustion mixture is ignited by the spark produced between the electrodes 13 so that the flame and the combustion products are discharged through an opening 6d of the end member 6 into a combustion chamber (not shown).
  • the kinetic energies of the atomized particles are generally very small so that the uniform distribution of the atomized particles may not be attained. This will be explained hereinafter in detail with reference to FIG.3.
  • the atomized fuel particles discharged from the atomizing surface 18 of the horn start to fall as indicated by B in FIGS, and the atomized fuel of relatively large particle sizes tends to spread far away from the extension of the axis of the horn 1. In some'cases, the atomized fuel particles of horn 1,so that the desired combustion mixture zone.
  • the combustion efficiency is substantially reduced.
  • the atomized fuel particles have rather slow speeds so that they are easily susceptible to the air flow. As a result, the combustion tends to pulsate, and the flames tend to leap, resulting in increased noise to the detriment of the environment.
  • the atomized fuel particles may be distributed so that higher combustion efficiency may be attained. That is, the atomized fuel particles discharged from the atomizing surface 18 of the horn 1 are carried away by the straightened air flow passing through the space 28 between the hom l and the inner mixing vane assembly 9. Thereafter, the fuel particles are whirled by and mixed with the whirling air flow emerging out of the inner mixing vane assembly 9.
  • the optimum airfuel mixture may be formed, so that the combustion efficiency may be much enhanced and the pulsation in combustion and the leaping of flames may be prevented, thus resulting in the minimization of combustion noise.
  • the present invention provides the outer mixing vane assembly 8 coaxially and outwardly of the inner mixing vane assembly 9 so that the combustion mixture formed mainly by the straightened air flow passing through the space 28 and the whirling air flow passing through the inner vane assembly 9 may be surrounded by the whirling air flow passing from the outer mixing vane assembly 8. Therefore, the fuel particles which have been spread away from the vortex of the air-fuel mixture may be returned to the air-fuel mixture zone.
  • the whirling air flow emerging from the outer mixing vane assembly 8 flows along the inner surface of the end member 6 and then converges toward the axis of the burner by the radially extending flange portion 6c so that the fuel particles which have been spread out of the combustion mixture zone may be returned to and concentrated in the mixture zone.
  • the diverging wall portion 6a of the end member 6 is provided so that the velocity of the whirling air flow emerging out of the outer mixing vane assembly 9 may be so suitably adjusted that the vortex of the combustion mixture may not be unnecessarily expanded by the whirling air flow emerging from the outer mixing vane assembly 8 and so that the noise due to the whirling air flow from the outer mixing vane assembly may be minimized.
  • the burners utilizing the ultrasonic wave generators for atomizing the fuel oils are not adapted to be used with all of liquid fuels, and the atomization of liquid fuels is dependent upon the properties of liquid fuels used and of the material forming the atomizing surface 18 of the horn 1. More particularly, the atomization is especially influenced by the surface tensions of the fuel oils and the properties of the material of the atomizing surface 18. Therefore the inventor made extensive studies of the effects of the surface tensions of liquid fuels upon the atomization time.
  • the surface tension of kerosene whose inherent v surface tension is 26 dynes per centimeter was varied by adding a mixture consisting of water and isopropyl alcohol, and the atomization time of kerosene with various surface tensions was measured.
  • the experimental results are shown in MG. 6.
  • the experiments showed that when the atomizing surface 18 is made of aluminum, the atomization is much enhanced than when the surface is made of other materials.
  • the characteristic curve a shows the atomization time when the aluminum atomizing surface 18 was used; the curve b, when the atomizing surface was made of aluminum-plated soft steel; and the curve 0, when the soft steel atomizing surface was used. From FIG.6 it is seen that the atomization by the aluminum atomizing surface is much improved and is almost independent of the surface tension of fuels used. In case of the'soft steel atomizing surface, the atomization time becomes longer and is considerably influenced by the surface tension of liquid fuels.
  • FIG.7 is illustrated the relation between, the electrical input power (plotted along the abscissa) and the atomization speed, that is the volume of fuel atomized per minute (plotted along the ordinate). It is seen that when the aluminum atomizing surface or aluminumplated atomizing surface is used, the volume of fuel atomized per unit of electrical input power is much increased. This means that the heat dissipation from the vibrations of the ultrasonic wave generator are less, so that the service life of the burner may be increased and the noise may be minimizedpln summary, it is very important that the atomizing surface. 18 must be made of or plated with a material whose properties may facilitate the atomization of liquid fuels.
  • the brackets are bifurcated, and the arms 22 of the horn 1 are held between the arms of the brackets 10 through the vibration isolators 19a. Since the bifurcated arms of the brackets 10 may be firmly tightened by means of adjusting screws 23, the arms 22 of the horn 1 may be firmly held in position.
  • the second variation of the method for mounting the horn 1 will be described.
  • the circle of the horn 1 which corresponds to the node are formed equiangularly a plurality of blind holes 23, and the pointed ends of brackets 24, 25 and 26 are fitted into these holes 23 to support and firmly hold in position the horn 1.
  • one of the brackets may be a screw 24 which is screwed into an internally threaded member 27 fixed to or formed in the outer duct or housing 5 so that when the screw 24 is tightened or loosened, it may be moved toward or away from the horn 1 in order to fit into or release out of the hole 23 the pointed end of the screw 24.
  • the second variation describedabove has an advantage that since the horn lis supported and held in position at the nodal position by the brackets or the like, the vibrations are almost not transmitted to the outer duct or housing 5 even when no vibration isolatorsareused.
  • a liquid fuel burner comprisingan ultrasonic wave generator
  • a liquid fuel burner as set forth in claim 1 wherein said horn is supported and held in position at the nodal position by said supporting means. 4. A liquid fuel burner as set forth in claim 1 wherein said atomizing surface of said horn is made of material whose adhesivity to fuel oils is low.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Pressure-Spray And Ultrasonic-Wave- Spray Burners (AREA)
US00246848A 1971-04-26 1972-04-24 Liquid fuel burner Expired - Lifetime US3796536A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP3347071U JPS4729827U (ja) 1971-04-26 1971-04-26
JP5822571U JPS4815826U (ja) 1971-07-03 1971-07-03
JP9082171A JPS52266B2 (ja) 1971-11-12 1971-11-12

Publications (1)

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US3796536A true US3796536A (en) 1974-03-12

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US00246848A Expired - Lifetime US3796536A (en) 1971-04-26 1972-04-24 Liquid fuel burner

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US (1) US3796536A (ja)
DE (1) DE2220538C2 (ja)
FR (1) FR2136639A5 (ja)
GB (1) GB1388036A (ja)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3860173A (en) * 1970-02-03 1975-01-14 Naoyasu Sata Non-polluting combustion engine having ultrasonic fuel atomizer in place of carburetor
US3904347A (en) * 1972-11-17 1975-09-09 Matsushita Electric Ind Co Ltd Combustion apparatus with ultrasonic vibrator
US3932109A (en) * 1973-02-22 1976-01-13 Minnesota Mining And Manufacturing Company Ultrasonic burner means
US4081233A (en) * 1975-06-19 1978-03-28 Matsushita Electric Industrial Co., Ltd. Combustion device
DE2743863A1 (de) * 1976-09-29 1978-03-30 Matsushita Electric Ind Co Ltd Brenner mit einem ultraschallschwinger
DE2749859A1 (de) * 1976-11-08 1979-05-10 Sono Tek Corp Brenner mit zerstaeubung der fluessigbrennstoffe mittels ultraschall
US4301968A (en) * 1976-11-08 1981-11-24 Sono-Tek Corporation Transducer assembly, ultrasonic atomizer and fuel burner
US4536151A (en) * 1982-12-01 1985-08-20 J. Eberspacher Mixture preparation for engine-independent heaters
US4732322A (en) * 1985-06-25 1988-03-22 J. Eberspacher Liquid fuel ultrasonic atomizer construction for a heater
US5122053A (en) * 1988-11-17 1992-06-16 Gert Basten Apparatus and method for the combustion of liquid or gaseous fuels
WO1994014003A1 (en) * 1992-12-15 1994-06-23 Bha Group, Inc. Acoustically enhanced combustion method and apparatus
US5785012A (en) * 1992-12-15 1998-07-28 Bha Group Holdings, Inc. Acoustically enhanced combustion method and apparatus
US6189320B1 (en) * 1996-12-20 2001-02-20 Siemens Aktiengesellschaft Burner for fluidic fuels having multiple groups of vortex generating elements
US6524098B1 (en) * 2000-05-16 2003-02-25 John Zink Company Llc Burner assembly with swirler formed from concentric components

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB678176A (en) * 1947-01-30 1952-08-27 Eggo Jacobus Buiskool Improvements in or relating to oil fuel burners
US2855244A (en) * 1955-06-03 1958-10-07 Bendix Aviat Corp Sonic liquid-spraying and atomizing apparatus
US3103310A (en) * 1961-11-09 1963-09-10 Exxon Research Engineering Co Sonic atomizer for liquids
US3275059A (en) * 1965-05-10 1966-09-27 Little Inc A Nozzle system and fuel oil burner incorporating it
US3672812A (en) * 1969-12-09 1972-06-27 Burmeister & Wains Mot Mask Fuel burner unit for mounting in a common air box

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB989342A (en) * 1960-09-22 1965-04-14 Lucas Industries Ltd Air swirlers for burners
US3200873A (en) * 1962-06-04 1965-08-17 Exxon Research Engineering Co Ultrasonic burner
US3155141A (en) * 1962-06-18 1964-11-03 Little Inc A Apparatus for atomizing and burning a liquid fuel
US3474969A (en) * 1967-08-28 1969-10-28 Mobil Oil Corp Air atomizing oil burner

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB678176A (en) * 1947-01-30 1952-08-27 Eggo Jacobus Buiskool Improvements in or relating to oil fuel burners
US2855244A (en) * 1955-06-03 1958-10-07 Bendix Aviat Corp Sonic liquid-spraying and atomizing apparatus
US3103310A (en) * 1961-11-09 1963-09-10 Exxon Research Engineering Co Sonic atomizer for liquids
US3275059A (en) * 1965-05-10 1966-09-27 Little Inc A Nozzle system and fuel oil burner incorporating it
US3672812A (en) * 1969-12-09 1972-06-27 Burmeister & Wains Mot Mask Fuel burner unit for mounting in a common air box

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3860173A (en) * 1970-02-03 1975-01-14 Naoyasu Sata Non-polluting combustion engine having ultrasonic fuel atomizer in place of carburetor
US3904347A (en) * 1972-11-17 1975-09-09 Matsushita Electric Ind Co Ltd Combustion apparatus with ultrasonic vibrator
US3932109A (en) * 1973-02-22 1976-01-13 Minnesota Mining And Manufacturing Company Ultrasonic burner means
US4081233A (en) * 1975-06-19 1978-03-28 Matsushita Electric Industrial Co., Ltd. Combustion device
DE2743863A1 (de) * 1976-09-29 1978-03-30 Matsushita Electric Ind Co Ltd Brenner mit einem ultraschallschwinger
DE2749859A1 (de) * 1976-11-08 1979-05-10 Sono Tek Corp Brenner mit zerstaeubung der fluessigbrennstoffe mittels ultraschall
US4301968A (en) * 1976-11-08 1981-11-24 Sono-Tek Corporation Transducer assembly, ultrasonic atomizer and fuel burner
US4536151A (en) * 1982-12-01 1985-08-20 J. Eberspacher Mixture preparation for engine-independent heaters
US4732322A (en) * 1985-06-25 1988-03-22 J. Eberspacher Liquid fuel ultrasonic atomizer construction for a heater
US5122053A (en) * 1988-11-17 1992-06-16 Gert Basten Apparatus and method for the combustion of liquid or gaseous fuels
WO1994014003A1 (en) * 1992-12-15 1994-06-23 Bha Group, Inc. Acoustically enhanced combustion method and apparatus
US5785012A (en) * 1992-12-15 1998-07-28 Bha Group Holdings, Inc. Acoustically enhanced combustion method and apparatus
US6189320B1 (en) * 1996-12-20 2001-02-20 Siemens Aktiengesellschaft Burner for fluidic fuels having multiple groups of vortex generating elements
US6524098B1 (en) * 2000-05-16 2003-02-25 John Zink Company Llc Burner assembly with swirler formed from concentric components

Also Published As

Publication number Publication date
DE2220538C2 (de) 1982-11-25
GB1388036A (en) 1975-03-19
DE2220538A1 (de) 1972-11-09
FR2136639A5 (ja) 1972-12-22

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