JPS6352949B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to ultrasonic transducer assemblies and, more particularly, to ultrasonic liquid atomizers.

No. HL Berger and CRBrandow, U.S. Pat.
Liquid atomizers, such as the atomizer disclosed in US Pat. No. 4,153,201, include radially extending channels in the atomizer section for introducing liquid into the atomizer. Typically, however, the liquid supply tube and the atomizer are arranged axially with respect to each other and the radially extending flow is connected, for example using a connecting tube and a nipple, to connect the atomizer to the liquid supply tube. The channel and the liquid supply pipe are connected. When installed correctly, the connecting tube and nipple provide a satisfactory connection between the atomizer and the liquid supply tube. However, the connections between the nipple, the connecting tube, the flow path of the atomizing section, and the liquid supply tube are prone to leakage. Additionally, making all the connections and making sure they are leak-proof is a time-consuming and tedious process.

Atomizers of the type described above can be supported by an air duct, for example when used as a fuel atomizer in a domestic fuel burner. For example, the atomizer disclosed in Patent No. 4,153,201 is fixed to this blast pipe. An annular flange on which a spider is fixed is connected to the atomizer, the flange being spaced apart by the spider and bolted to the blast pipe. Although the atomizer is securely supported in this manner, it requires a large amount of equipment and is time consuming to install.

It is an object of the present invention to provide an improved ultrasonic liquid atomizer.

It is also an object of the invention to improve liquid application to ultrasonic liquid atomizers.

Another object of the invention is to improve liquid application to the atomizing surface in an ultrasonic liquid atomizer.

Yet another object of the invention is to improve the connection of a liquid supply tube to an ultrasonic liquid atomizer.

Yet another object of the invention is to improve the mounting of ultrasonic liquid atomizers.

Yet another object of the invention is to support an ultrasonic liquid atomizer using a liquid supply tube.

Yet another object of the present invention is to provide an improved apparatus for preventing premature atomization of liquid in the liquid flow path leading to the atomizing surface of an ultrasonic liquid atomizer. .

It is also an object of the invention to provide improved driving means for ultrasonic atomizers.

Yet another object of the invention is to improve the mounting of drive means in ultrasonic atomizers.

According to the invention, the liquid to be atomized is introduced axially into the liquid atomizer and is conveyed to the atomization surface via an axially extending channel. Therefore, the present invention
It eliminates the need to provide a radially extending connection to the atomizer for supplying liquid.
Furthermore, according to the invention, the number of connections required to connect the liquid supply pipe to the atomizer is reduced, the manner of connection is simplified, and the construction of the atomizer is also simplified.

Typically, the liquid supply tube and the atomizer are arranged axially with respect to each other. In this case, according to the invention, the liquid supply pipe is connected to the atomizer by one connection.

According to one feature of the invention, the channel comprises a tubular member extending within at least a portion thereof, and means are provided for receiving the tubular member.

According to another feature of the invention, the tubular member comprises:
It is constituted by a liquid supply pipe extending into the axially extending channel and supporting the atomizer.

The tubular member may be provided with means for connecting it to a liquid supply means, or it may form part of a liquid supply conduit as described above.

According to another feature of the invention, a tubular member or Means are provided for cooperating with the liquid supply tube. Such measures improve the performance of the atomizer.

Preferably, the tubular member (liquid supply tube) is threaded and the atomizer is also provided with a threaded section for receiving this threaded tubular member. The tubular member or liquid supply pipe is therefore preferably connected to the atomizer by a threaded connection. Means such as a sealing compound is applied to the threaded joint to prevent fuel from leaking into the drive means. In a preferred embodiment, the threads of the atomizer for receiving the tubular member start at the beginning of the output section or at some short distance within this output section and extend toward the atomization surface. The lever extends within this output section.

In a preferred embodiment, the tubular member forms part of a liquid supply tube, the liquid supply tube having a threaded section spaced from the end thereof and connected to the end of the threaded section for dispensing the mist. and a buffer sleeve extending to or near the exposed surface.

According to a preferred embodiment of the invention, the atomizer has an improved connection between the atomizer and the tubular member or the liquid supply pipe and/or between the front and rear sections of the atomizer and the atomization drive means. A tubular member or liquid supply tube having a threaded end or threaded section screwed into the front section of the atomizer cooperates with other means in the rear section of the atomizer adjacent to the drive means. means for drawing the rear and front sections together when the tubular member or liquid supply tube is screwed into the front section of the atomizer. This provides symmetrical mounting of the tubular member or liquid supply tube, with the effective mounting surface of the tubular member or liquid supply tube being at or near the proper nodal plane of the actual mounting surface. The means for drawing the sections together is shown with an annular flange or step on the tubular member or liquid supply tube and a corresponding annular flange or step on the rear section, preferably adjacent the drive means. When the tubular member or liquid supply tube is screwed into the front section of the atomizer, these annular flanges engage and draw the rear section towards the front section of the atomizer relative to the drive means.

According to another feature of the invention, a metal decoupling sleeve is provided to prevent premature atomization of the liquid in the liquid flow path leading to the atomizing surface of the ultrasonic liquid atomizer. ing.

According to a further feature of the invention, a metal tube extends in the axial flow path from one end of the ultrasonic atomizer to the atomization surface, a portion of which constitutes a buffer sleeve. The tubular member and buffer sleeve described above are therefore formed by one piece of metal tubing. Preferably this one piece metal tube is constituted by the liquid supply tube and is provided with an annular flange that engages an annular flange at the rear of the atomizer.

According to still another feature of the invention, a transducer for atomizing a liquid includes an atomizing section having an atomizing surface and an ultrasonic drive disposed adjacent the atomizing section. and means;
The atomizing section and drive means have a flow path extending axially therethrough to the atomizing surface, and the transducer further directs the applied liquid through the axially extending flow path to the atomizing surface. A transducer is provided which includes means for coupling the drive means and the atomizing section for atomizing in response to electrical excitation of the drive means. The drive means may consist of one or more piezoelectric elements.

According to another feature of the invention, the transducer is of the type disclosed in U.S. Pat. No. 4,153,201 and includes a front ultrasonic horn section, a rear ultrasonic horn section and a drive means having at least one piezoelectric disc sandwiched between a section and a rear section; means for clamping said front and rear ultrasonic horn sections to a drive element; and an output section extending from the horn section and terminating in the atomization surface. A flow path is provided that extends axially through the front and rear sections and the drive element to the atomizing surface, the flow path extending axially from the end of the rear section through the drive element and the front section to the end of the front section. Extends to. The transducer assembly includes a symmetrical double dummy ultrasonic horn with a sandwiched driving element.

In a preferred embodiment, the tubular member (liquid supply tube) extends through the drive means and the end of the tubular member is located at or near the atomizing or output section. The drive means includes an electrode and one or more drive elements, all of which have an aperture through which the tubular member extends. Means are provided for insulating the electrode and drive element from the tubular member. Preferably, the end of the tubular member is threaded into or near the atomization or output section.

According to yet another feature of the invention, an improved drive means is provided comprising a pair of annular piezoelectric elements sandwiching an annular electrode. The diameter of the electrode is reduced in order to provide clearance around the electrode for mounting a tensioner, such as a rod or bolt, which heretofore was intended to pass through the electrode. Bolts or rods extend between the sections of the atomizer and connect the drive means to the atomizer. The clearance provided by the reduction in electrode diameter eliminates the need to insulate the bolt from the electrode. In a preferred embodiment, the diameter of the piezoelectric element is smaller than the diameter of the electrode, and a ring or sleeve of insulating material is disposed adjacent the electrode and around the piezoelectric element;
The outer diameter of this ring is approximately equal to the outer diameter of the electrode.

According to another feature of the invention, the annular piezoelectric element is centered by the axial channel, so that it is not necessary to provide centering means, such as a circular recess, in the atomizing surface adjacent to the piezoelectric element. Gender is eliminated.

The liquid supply tube and the tubular member which may be or form part of the buffer sleeve may be made of a material that is acoustically mismatched to the atomizer; It was found that it was not necessary to use these substances. For example, in the case of an aluminum atomizer, a material that is acoustically mismatched to aluminum, such as copper or steel, may be used to form the tubular member or liquid supply tube and the decoupling sleeve, or aluminum may be used to form the tubular member or liquid supply tube and decoupling sleeve. good.

These and other features of the invention will become apparent from the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings.

It is to be understood that the accompanying drawings, in which like parts are designated by like reference numerals, illustrate only one example of the invention and are not intended to limit the invention thereto.

A typical pressurized atomizing fuel burner includes a blast tube into which fuel is applied and an atomized fuel-air mixture is discharged. Such a typical burner has a concentric fuel pipe configuration as shown in FIG. For clarity of illustration, only the blow pipe housing 10, fuel pipe 11, and atomization nozzle 12 are shown. Typically, the fuel line in a typical household burner is 3/8 inch (9.4 mm)
diameter steel fuel tube 11, which enters the duct housing 10 from the rear and extends along the central axis of the duct housing and extends from the spiral plate 13 or the like at the front of the duct housing. Pressure nozzle 1 near
Ends with 2.

In the essential ultrasonic fuel burner of the fuel burner 15 shown in FIG. 2, which is of the type disclosed in U.S. Pat. Vessel 17
Fuel oil is introduced into the atomization section 16 of. The radially extending channel 18 is connected to the axially extending channel 20.
, and this flow path 20 terminates in an atomization surface 22 . To connect the atomizer 17 to an existing fuel pipe, such as pipe 11 of FIG. 1 or a similar fuel pipe 11A of FIG. 2, a connecting hose 24 and a fuel nipple 26,
28 can be used. To make this connection, the fuel tube 11A of FIG. 2 is plugged at its distal end 30 with a plate or cap 32 or other suitable means. The plate or cap 32 is secured by threaded connections or adhesive. edge 30
A hole is drilled in the tube 11A in the vicinity of and a nipple 26 is installed. A nipple 28 is installed in the radially extending channel 18 . A connecting tube 24, a flexible plastic hose, is connected to these two nipples to complete the connection between the fuel line and the atomizer. The nipple is typically connected to the atomizer and fuel line by a threaded connection, and the hose 24 is fitted to the nipple. If desired, the hose 24 may be clamped to the nipple.

The ultrasonic atomizer 17 itself has an annular mounting plate 3
6 to the front end 34 of the blast tube, and the mounting plate 36 has a spider 37 integrated therein for spacing the plate 36 and the atomizer from the front end 34 of the blast tube. Typically the air duct housing 10
A is fixed to the fuel burner in a conventional manner.

Connecting fuel line 11A to ultrasonic atomizer 17 as shown in FIG. 2 has a number of drawbacks.
For example, each connection between fuel tube 11A and radially extending passageway 18 is susceptible to leakage.
Therefore, the connection between the nipple 26 and the fuel pipe 11A,
Connection between hose 24 and nipple 26, hose 24
The connection between the nipple 28 and the nipple 28, and the connection between the nipple 28 and the radial flow path 18 are all potential sources of leakage. Additionally, the ultrasonic atomizer must be secured to the blast tube housing, which requires mounting hardware such as annular plates, spiders, and bolts.

The burner shown in FIG.
Front horn section 44 as disclosed in No. 4153201
A solid drive element 40, 42 is generally provided sandwiched between the rear horn section 46 and the rear horn section 46. An electrode 48 is inserted between these drive elements 40 and 42. Drive elements 40, 42 and electrodes 48 are disc-shaped and section 4
4, 46, drive elements 40, 42 and electrodes 48 are held together by bolts extending through the drive elements and electrodes, and means are provided to isolate the bolts from the electrodes.

According to the invention, the fuel pipe itself (Figs. 3, 4 and 7) or the pipe connected to the fuel pipe (Fig. 5)
) is axially received in the atomizer and extends axially through the rear section, drive element and electrodes to the front section.

Referring to FIGS. 3 to 5 and 7,
The rear section 50 has an axially extending bore or passage 5.
2 is provided. The drive elements 54, 56 and the electrodes 55 are of annular form, ie, washer-shaped, and have a central opening or passageway. The piezoelectric annular drive element is manufactured in Cleveland, Ohio.
Available from Venitron Corporation. Front section 58 is provided with an axially extending threaded bore or passageway 60 which extends axially through passageway 20 in atomization section 16A to atomization surface 22A.
It communicates with A. The axial flow passages of the rear section, the front section and the atomization section, and the drive element and electrode openings are axially disposed to form a fuel flow passage indicated generally at 62; extends axially from the exterior of the rear section to the atomization surface. The relative diameters of the individual channels and openings forming the overall axially extending channel 62 of FIGS. 3-5 are shown in FIG.

In the atomizer of FIGS. 3-5, the rear section 50 has a central bore 52 of diameter a, and the central openings 64, 66 of the drive elements are connected to the ends 56A, 5 of the drive elements.
4A has a diameter b and between them a diameter a, the central opening 65 of the electrode 55 has a diameter b, and the front section has a threaded bore of diameter c located adjacent to the drive element. 60, which communicates with the central bore 20A of diameter d of the atomizing section 16A. Threaded section 60 connects to connecting tube 70
(FIG. 5) or the end 6 of the fuel tube itself (FIGS. 3 and 4).
Accept 9. Fuel tube 11B (FIG. 3) or connecting tube 70 (FIG. 5) extends through channel 52 in rear section 50, through drive element and electrode openings 64-66, and into front section 58. The end 68 of the tube 70 or the end 69 of the fuel tube is threadedly connected to the threaded section 60 and a seal or bonding compound is applied to this connection to prevent leakage.

Referring to FIG. 3, fuel tube 11B has a threaded end 69 that is received in threaded section 60 of front section 58. Referring to FIG. According to the present invention, a buffer sleeve 70 of Teflon or other suitable material such as aluminum, steel, copper, etc., shown in FIG.
It extends to the front of the opening of A. This buffer sleeve 7
0 has a threaded end section 71, which is screwed into the threaded section 60 of the front section 58 of the atomizer.

Referring to FIG. 4, fuel tube 11C has a small diameter section 72 extending from threaded section 69A.
It is equipped with This small diameter section 72 is a buffer sleeve and is made of the same material as the fuel tube 11C.
By providing a buffer sleeve as part of the fuel tube 11C, a leak-proof flow path is created throughout the atomizer. When this metal fuel tube buffer sleeve is used in place of a Teflon buffer sleeve, it eliminates the need for plastic components near potentially hot areas. Manufacturing is also simplified by using one piece. The diameter of the buffer sleeve portion of the fuel tube is such that it lightly contacts the fuel passageway 20A formed in the front section 58.
This eliminates a forced fit that would exert unnecessary pressure and degrade performance, and also eliminates the risk of acoustic coupling between the tube and the front section due to a tight fit.

As shown in FIG. 5, a tubular member 70 may be threaded into the atomizer and its end 74 may be secured to fuel tube 11A. For example, tubular member 70 is connected to fuel line 11A by a bushing or union coupling 76. The atomizer shown in FIG. 5 uses a general Teflon buffer sleeve 77.

Referring now to FIG. 7, an atomizer similar to that of FIG. The rear section 50A is also provided with an annular flange or step 92 located adjacent the drive means. These flanges 90 and 92 engage when the fuel tube 11D is screwed into the threaded section 60, and the rear section 50A and the front section 58 are drawn together, sandwiching the drive means. The diameter of bore 52A in rear section 50A adjacent flange 92 is "e" and the diameter of the bore in this flange is "a". This configuration provides approximately equal attachment forces for the front and rear sections of the atomizer. The effective mounting surface of the fuel tube in the atomizer is considered to be midway between the front section and the rear section, ie approximately at the nodal surface. An advantage of this configuration is that the fuel tube provides a means of securing both sections of the atomizer before torqueing the bolts 82. Another advantage of this configuration is that it reduces vibrations in the fuel tubes that extend beyond the rear section, with little or no vibration in the fuel tubes that extend beyond the rear section. Yet another advantage of this configuration is that it reduces the sensitivity of the atomization action to the length of the fuel tube, and it reduces the sensitivity of the atomization action to the length of the fuel tube or There is a reduction in sensitivity to the degree of tightening of the tubular member, and also a reduction in sensitivity to the manner in which the tubular member is coupled to the external fuel tube. Otherwise, such factors may change the resonant frequency of the fuel tube and atomizer, resulting in an increase in the impedance of the atomizer and a decrease in the value of Q. This means that the atomizer doesn't actually work.

Acoustically mismatched materials can be used as fuel tubes or tubular members and buffer sleeves (e.g.
It has been found that this is not necessary (copper, steel, etc. fuel tubes, tubular members, or sleeves) for aluminum atomizer sections. Thus, aluminum fuel tubes and buffer sleeves can be used with aluminum rear and front atomizer sections.

The center electrode is a nylon or other electrically insulating medium tube 7
8 from the fuel pipes 11B, 11C, 11D or the connecting pipe 70, an electrically insulating medium pipe 78 is arranged around the fuel pipe or the connecting pipe at a position within the electrode opening 65. Also, this insulator 78
also extend into the drive element openings 64, 66, shielding the fuel or connecting tube from the inner surface of the drive element (which may be plated) adjacent to the electrodes. A nylon or other electrical insulator tube 78 extends between the large diameter "b" sections and the small diameter "a" sections (FIG. 6). A ring or gasket 80 of rubber or other composition connects the electrode 55.
The driving elements 54 and 56 are arranged adjacent to the peripheries of the drive elements 54 and 56. Drive elements 54, 56 and electrodes 55 have a small outer diameter, thus providing clearance for bolts 82 that connect the drive elements of the atomizer to front section 58 and rear section 50. Thus, the need for holes in the electrodes and drive elements and for insulating the bolts from the electrodes is eliminated.

The inner surfaces of the anterior and posterior sections also have annular recesses removed. These recesses were used to center the piezoelectric crystal disk. However, according to the invention, centering is provided by the axial apertures of the piezoelectric crystal and electrodes.

It was found that even if the piezoelectric crystal had an axial opening, the performance did not deteriorate. One reason for this is that there is an axial central void throughout the atomizer.

Thus, as shown in FIGS. 3-7, fuel is applied axially to the atomization surface in the atomizer.

By providing an axial flow path in the atomizer as shown in Figures 3 to 7, the atomizer can be directly supported by the fuel pipe as shown in Figures 3, 4, and 7. Alternatively, the tubular member 70 as shown in FIG.
It can also be supported indirectly by This eliminates the need for the installation equipment and corresponding installation time shown in FIG.

Tubes such as tube 70 or fuel tubes 11B, 11C, 11D may be connected to the atomizer in other ways than described above with respect to FIGS. 3-7. for example,
An adhesive may be used to secure the tube or the tube may be connected to another location on the atomizer. Additionally, the atomizer can be provided with a tube such as tube 70 permanently affixed to the atomizer.

The fuel burner of FIGS. 3-7 otherwise operates as disclosed in U.S. Pat. No. 4,153,201.

Although the present invention has been described as being applied to fuel burners, particularly fuel burners for space heating, it will be apparent to those skilled in the art that it can be used to great advantage in other applications as well. The present invention can also be used to supply fuel to internal combustion engines or jet engines, or to atomize liquids other than fuel, such as water or paint.

Although preferred embodiments of the invention have been particularly disclosed, those skilled in the art will recognize that various modifications and deletions can be made without departing from the scope of the invention.
For example, the fuel tube can be brought into axial communication with the atomizer nozzle by special arrangements other than those described above.

[Brief explanation of drawings]

Figure 1 is a side cross-sectional view showing a part of the blast pipe of a general pressurized atomized fuel burner, and Figure 2 is a U.S. patent
4153201; FIG. 3 is an axial cross-sectional view of the atomizer of the ultrasonic fuel burner constructed in accordance with the present invention; FIG. FIG. 4 is an axial cross-sectional view similar to FIG. 3, showing the fuel tube received in the atomizer, with a small diameter section acting as a damping sleeve. FIG. 5 is an axial cross-sectional view of an atomizer similar to FIG. 3, with one end of the tubular member received in the atomizer and the other end connected to a fuel line. 6 is an enlarged cutaway view of the atomizer of FIGS. 3-5, showing the fuel flow path extending through the atomizer and the diameter of the flow path at various locations in the atomizer. The figure shown, and the seventh
4 is an axial cross-sectional view of an atomizer similar to FIG. 4, in which the tubular member has an annular flange, and the rear section of the atomizer also has an annular flange, and the tubular member is screwed onto the atomizer. FIG. 6 is a diagram showing how these flanges engage when inserted. 10...Blow pipe housing, 11, 11A, 11B,
11C, 11D... Fuel pipe, 12... Atomizing nozzle, 15... Fuel burner, 16, 16A... Atomizing section, 17... Atomizer, 18... Channel extending in the radial direction, 20, 20A... Channel extending in the axial direction, 22, 22A... Atomization surface, 24... Connection hose, 26, 28... Nipple, 36... Annular mounting plate, 37... Spider, 40, 42... Drive element, 44... Front horn section, 46... Rear horn section, 48... Electrode, 50... Rear section,
52... Channel extending in the axial direction, 54, 56... Drive element, 55... Electrode, 58... Front section, 60
...Threaded channel extending in the axial direction, 62...
...Fuel flow path, 64, 65, 66...Central opening, 7
0... Connection pipe.

Claims (1)

[Claims] 1. In a transducer that atomizes liquid,
an atomizing section or output section having an atomizing surface; and a drive means connected to the output section, the output section and the drive means having a flow path extending axially therethrough to the atomizing surface. further comprising: a tubular member disposed at one end in the axially extending channel for introducing liquid into the transducer and applying it to the atomizing surface; means adjacent thereto for receiving said end of said tubular member; and said drive means adapted to atomize liquid applied through said tubular member to said atomizing surface in response to electrical excitation of said drive means. and means for coupling the output sections. 2. further comprising a front ultrasonic horn section, said output section extending from said front section and terminating in said atomization surface, and further comprising a rear ultrasonic horn section, said drive means being in communication with said front section; A transducer as claimed in claim 1, further comprising means inserted between the rear section and for clamping the front section and the rear section relative to the drive means. 3 The drive means includes two piezoelectric drive elements each having an axially extending through opening forming a part of the axially extending flow path, and a through opening forming a part of the axially extending flow path. 3. The transducer according to claim 1, wherein said electrode is inserted between said piezoelectric driving elements. 4. The transducer according to claim 1, wherein the receiving means and the tubular member include a threaded portion, and the threaded receiving means receives the tubular member in a threaded manner. . 5. Claim 1 further comprising a buffer sleeve connected to said transducer and extending from at or near said atomization surface to said tubular member.
The transducer according to any one of items 1 to 4. 6. The buffer sleeve according to claim 5, wherein the buffer sleeve comprises a threaded section and the output section comprises a threaded section, the buffer sleeve being threadably received in the output section. Transducer. 7. The tunnel lass deflector according to claim 5, wherein the buffer sleeve is connected to the tubular member. 8. The transducer of claim 7, wherein the buffer sleeve and the tubular member are in one piece. 9. The transformer of claim 8, wherein the one piece is externally threaded and the transducer is also mating threaded to secure the one piece to the transducer. Juusa. 10. Claims 2-9, comprising means associated with said rear section and said tubular member for drawing said rear section and output section together upon securing said tubular member to said output section. The transducer according to any of the above. 11. The transducer of claim 10, wherein said pulling means comprises a corresponding annular flange portion of said tubular member and said rear section, said tubular member being threadably received in said output section. 12. The transducer according to any one of claims 1 to 11, wherein the other end of the tubular member is connected to means for supplying liquid to the transducer. 13. Claim 12, further comprising means for coupling the other end of the tubular member to the liquid supply means.
The transducer described in section. 14. A transducer according to any one of claims 5 to 11, wherein the tubular member or both the tubular member and the buffer sleeve form part of a liquid supply tube. 15. A transducer according to any one of claims 1 to 14, wherein the receiving means is located at or near a nodal surface. 16 The diameter of said drive means is less than the diameter of said front and rear sections adjacent said drive means, said means for clamping said front and rear sections having a plurality of tensioners connecting said front and rear sections. Prepare,
16. A transducer as claimed in any one of claims 2 to 15, wherein the tensioners extend beyond the diameter of the drive means between the front and rear sections. 17. The transducer of claim 16 including a tubular sleeve extending around each piezoelectric element. 18. The transducer of claim 17, wherein the diameter of the piezoelectric element is less than the diameter of the electrode, and the outer diameter of the tubular sleeve is approximately equal to the diameter of the electrode.