Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B17/00—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups
  • B05B17/04—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods
  • B05B17/06—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations
  • B05B17/0607—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations generated by electrical means, e.g. piezoelectric transducers
  • B05B17/0623—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations generated by electrical means, e.g. piezoelectric transducers coupled with a vibrating horn
  • B05B17/063—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations generated by electrical means, e.g. piezoelectric transducers coupled with a vibrating horn having an internal channel for supplying the liquid or other fluent material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B17/00—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups
  • B05B17/04—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods
  • B05B17/06—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations
  • B05B17/0607—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations generated by electrical means, e.g. piezoelectric transducers
  • B05B17/0623—Apparatus for spraying or atomising liquids or other fluent materials, not covered by the preceding groups operating with special methods using ultrasonic or other kinds of vibrations generated by electrical means, e.g. piezoelectric transducers coupled with a vibrating horn

Definitions

• the present invention relates to a uitrasonic spraying device for fluids.
• fluids means very generally all types of traditional fluids such as solutions based on different compounds and / or inorganic or organic solvents, emulsions, suspensions, dispersions or analogues, as well as molten metals and alloys.
• this type of device is also used to generate powders by vaporization of the associated liquid phase.
• the uitrasonic spraying is based on the generation of standing surface waves, at the liquid-gas interface, organized in the form of a perfectly regular lattice.
• the distance between two consecutive peaks of the trellis determines the average diameter of the drops formed.
• a cylindrical element made of titanium v ibrant at 20 KHz cannot have an active face diameter greater than S0 mm on pain of causing superimposed unwanted radial vibration to appear there, which results in a heating followed by a break of the element.
• the active face of these sprayers has, according to its dimensions and shape, a succession of bellies and wave nodes and vibrates with a greater or lesser amplitude depending on whether one moves away or gets closer to the excitation axis.
• the present invention therefore aims to provide a radial spraying device for spraying large flow rates of fluids while maintaining a tight particle size distribution and ensuring perfect reliability in terms of the behavior of the constituent materials.
• the uitrasonic sprayer is characterized in that it comprises:
• a radial sprayer arranged in the form of a radiating crown projecting from said bar element, and tuned to the frequency of said converter
• the uitrasonic sprayer When used at high temperatures, the uitrasonic sprayer will preferably include one or more coupling rod elements, which also makes it easier to build the device.
• FIG. 1 represents a perspective view of the entire spray device according to the invention
• FIG. 2 represents a schematic side view of the device of FIG. 1,
• FIG. 3a represents a sprayer whose lateral face is cylindrical
• 0 - FIG. 3b represents a sprayer whose lateral face is convex
• the figure represents a part of the spraying device provided with an external supply, by an annular ramp,
• FIG. 5 represents a spraying device equipped with a liquid distributor
• FIG. 6 represents a spraying device equipped with a supply by capillary effect
• FIG. 7 shows a spray device for the treatment of liquids at high temperature, 0
• an electroacoustic converter of the piezoelectric excitation type. It can for example be of the "tripiet and Langevin" type as described in the book High Intensity Ultrasonics by B. Brown and J.E. GOODMAN.
• this electroacoustic converter will bear the reference 10.
• the spraying device optionally comprises at least one coupling bar 12, as well as a sprayer arranged in the form of a radial crown 1 projecting from the axial element supporting it by construction.
• the radial crown 14 is excited from the axial mode of the aforementioned element, on which it is centered. It will be noted that during the axial compression phase, the radial crown 14 expands, and vice versa.
• the radial ring 14 of the sprayer is arranged in the center of a half wavelength of the axial vibration.
• the external diameter D of the radial crown 14 is advantageously determined to ensure the vibration of said crown in resonance with the axial system. The calculation methods of such systems are well known to those skilled in the art and in particular, described in American patent No. 3,696,259.
• the diameter of the active crown is directly linked to the excitation frequency which can range from 10 to 100 KHz.
• the amplitude of vibration of the radial crown is homogeneous over the entire active area.
• the active lateral face of the radial crown 14 can be arranged in a cylindrical manner with an axis parallel to the axial vibration.
• This embodiment is illustrated in FIG. 3a.
• ia active side face of the radial collar 14 may assign a convex shape, the vibration amplitude varying in this case participationmen t ia a point opposite to another point of different level.
• the liquid to be treated can be supplied from the outside of the device near a nodai area, that is to say active egg, or even from the inside of the device by means of small diameter holes in areas of low stress.
• the means for supplying the liquid consist of an annular ramp 16 producing a direct flow over the connection zone 18 to the active side face of the crown 14.
• the means for supplying the fluid consist of a conduit 20 discharging the fluid into an annular distribution groove 22 formed in the vicinity of the upper part of the connection from the sprayer to the coupling rod.
• this distributor 22 allows the liquid to be treated to flow regularly and continuously towards the active face of the sprayer 14.
• the fluid is brought to the lower part of the sprayer by capillary effect and acoustic pumping.
• FIG. 7 relates to a spraying device intended to ensure the uitrasonic spraying of fluids carried at high temperature. It can in particular be metals or liquid alloys. In this case, the external ramp allowing the annular flow of the liquid is surrounded by an induction heating device bearing the reference 24. It is quite clear that this is a particular heating means and that in reality, the sprayer can be heated locally by any other means in the vicinity of the means for supplying fluid.
• the electroacoustic converter When the device according to the invention is applied to the spraying of liquid metals, it will also be necessary to place the electroacoustic converter in a sealed chamber ensuring its cooling, for example by a circulation of cooling fluids through double- walls of said chamber having the general reference 26.
• the exact dimensions of the radial element and of the coupling rod will advantageously be chosen to maintain the natural frequency of the converter at the target temperature.
• a titanium alloy sprayer using a 20 kHz converter and intended to operate at a temperature of 650 ° C., under a peak-to-peak amplitude of 10 ⁇ m, will be tuned cold on a frequency of the order of 21,200 Hz.
• the materials will be chosen according to the temperature level and the amplitudes required.
• the liquid supply can also be carried out from the very interior of the spraying device.
• FIG. 8 and 9 illustrate such an internal power supply.
• These will in particular be channels 28, preferably radial channels, arranged in the median plane of the radial crown 1 -.
• These channels 28 are connected to a central supply channel 30 opening into a zone of low stress 32 of one of these elements 5 of the coupling bar 12.
• the sprayer illustrated in Figure 9 is of the
• the two liquid supplies 34 and 36 are of the internal type, that is to say that the mixing takes place at the level of the central channel 30 coupled to the radial channels 28.
• the uitrasonic sprayer according to the invention can be applied to the spraying of metals and alloys, of chemical products.
• mineral or organic which can be put in liquid form or in solution, in the form of emulsions or crystalline suspensions.
• the dimensions and the shape of the chamber can be adapted according to the shape of the sprayer which can be flat, frustoconical or convex.
• a radial sprayer operating at 5 20 KHz can generate a mist of water drops of approximately 50 microns for a flow rate of at least 300 liters / hour and at an amplitude of i O microns .
• Another example of implementation according to the method relates to the manufacture of powders of tin / lead alloys.
• An alloy of the type 62/36/2 1 melting at 179 ° C. is sprayed using a radiai sprayer operating at 30 kHz with an amplitude of 6 microns peak to peak and a flow rate of 30 kg / hour. 95% of powder less than 80 microns and 56% of less than 40 microns are obtained.

Applications Claiming Priority (3)

Publications (2)

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ID=9402467

Family Applications (1)

Country Status (8)

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Family Cites Families (14)

• 1990
  • 1990-11-22 FR FR9014572A patent/FR2669561B1/fr not_active Expired - Lifetime
• 1991
  • 1991-11-22 DK DK92900618.7T patent/DK0558609T3/da active
  • 1991-11-22 WO PCT/FR1991/000930 patent/WO1992009373A1/fr active IP Right Grant
  • 1991-11-22 AT AT92900618T patent/ATE125733T1/de not_active IP Right Cessation
  • 1991-11-22 EP EP92900618A patent/EP0558609B1/fr not_active Expired - Lifetime
  • 1991-11-22 US US08/386,218 patent/US5632445A/en not_active Expired - Lifetime
  • 1991-11-22 DE DE69111824T patent/DE69111824T2/de not_active Expired - Lifetime
  • 1991-11-22 ES ES92900618T patent/ES2077391T3/es not_active Expired - Lifetime

Non-Patent Citations (1)

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