Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
  • B05B1/34—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to influence the nature of flow of the liquid or other fluent material, e.g. to produce swirl
  • B05B1/3405—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to influence the nature of flow of the liquid or other fluent material, e.g. to produce swirl to produce swirl
  • B05B1/341—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to influence the nature of flow of the liquid or other fluent material, e.g. to produce swirl to produce swirl before discharging the liquid or other fluent material, e.g. in a swirl chamber upstream the spray outlet
  • B05B1/3421—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to influence the nature of flow of the liquid or other fluent material, e.g. to produce swirl to produce swirl before discharging the liquid or other fluent material, e.g. in a swirl chamber upstream the spray outlet with channels emerging substantially tangentially in the swirl chamber
  • B05B1/3431—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to influence the nature of flow of the liquid or other fluent material, e.g. to produce swirl to produce swirl before discharging the liquid or other fluent material, e.g. in a swirl chamber upstream the spray outlet with channels emerging substantially tangentially in the swirl chamber the channels being formed at the interface of cooperating elements, e.g. by means of grooves
  • B05B1/3436—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means designed to influence the nature of flow of the liquid or other fluent material, e.g. to produce swirl to produce swirl before discharging the liquid or other fluent material, e.g. in a swirl chamber upstream the spray outlet with channels emerging substantially tangentially in the swirl chamber the channels being formed at the interface of cooperating elements, e.g. by means of grooves the interface being a plane perpendicular to the outlet axis

Definitions

• the present invention relates to liquid spray nozzles, in which a liquid to be sprayed is brought into a central swirl chamber by peripheral transfer channels tangentially injecting the liquid which swirls into the central vortex chamber and then leaves the central vortex chamber via a coaxial outlet passage to the atmosphere.
• Such spray nozzles may be used in sprayers, in combination with spray pumps with manual actuation or with a push gas, in particular for spraying cosmetic products.
• spray nozzles comprising a swirl chamber having a general shape of revolution around a longitudinal axis, limited by a peripheral wall, by a rear wall, and by a front wall pierced with a coaxial outlet hole.
• a coaxial circular channel surrounds the swirl chamber, and communicates with said swirl chamber through a plurality of first oblique peripheral transfer channels which inject the rotating liquid in a direction of rotation into the swirl chamber.
• a plurality of second transfer channels conduct the liquid from a liquid inlet and inject it into the coaxial circular channel in rotation in said direction of rotation.
• the first transfer channels are each limited by an outer face with a straight profile which tangentially connects to the peripheral wall of the swirl chamber, and which angularly connects to the inner wall of the coaxial circular channel.
• Said first transfer channels are each limited by an inner face with a straight profile which is angularly connected to the peripheral wall of the swirl chamber, and which is angularly connected to the internal wall of the coaxial circular channel.
• the cross section of the first transfer channels is gradually reduced from the coaxial circular channel to the swirl chamber.
• Such two-stage spray nozzles work relatively well for spraying liquids of low viscosity such as water, producing droplets of satisfactory sizes, of the order of 90 microns, distributed in a spray cone at the outlet of nozzle.
• the problem proposed by the present invention is both to reduce the size of the droplets sprayed at the outlet of a nozzle supplied with liquid, to ensure a homogeneous distribution. droplets in the spray cone in the case of relatively low and variable fluid pressures produced by manual pumps of cosmetic spray devices, and to achieve these effects with a spray nozzle of reduced diameter.
• a spray nozzle according to the invention for spraying liquids, comprises:
• a swirl chamber having a general shape of revolution around a longitudinal axis, limited by a peripheral wall, by a rear wall, and by a front wall pierced with a coaxial outlet hole,
• the transfer channels are each limited by an outer face of generally rectilinear profile and tangentially connecting to the peripheral wall of the swirl chamber, the transfer channels are each limited by an inner face having a concave profile over most of its length,
• the exit coaxial hole has a conical shape converging towards the exit.
• the total diameter of the nozzle is significantly smaller than that of two-stage nozzles.
• the droplet sizes sprayed at the outlet of the nozzle are much more weak than those obtained by the nozzles of the prior art mentioned above. It is estimated that about 30% is saved on the size of the droplets sprayed at the outlet, with an equal pressure generation system.
• the average distribution of droplets is homogeneous in the spray cone at the nozzle outlet.
• An advantageous effect of the invention is also a relative independence of the quality of spraying produced with respect to the pressures and flow rates supplied by the pusher device which introduces the liquid at the inlet of the nozzle.
• Another effect of this particular nozzle structure according to the invention is an acceptance of higher tolerances of concentricity of the outlet hole with respect to the swirl chamber when spraying relatively viscous liquids: the spraying is excellent when the hole of outlet is centered, but remains acceptable when the outlet hole is slightly off center. Good results can be obtained up to an offset offset of approximately 10% of the diameter of the outlet hole, for liquids whose viscosity is between 800 and 1000 mPa.s.
• each transfer channel is supplied by a peripheral longitudinal supply channel from the inlet of the nozzle.
• the inner face with a concave profile of the transfer channel is generally circular according to a radius of between one and a half and two times the radial distance DR between the corresponding peripheral longitudinal supply channel and the swirl chamber. .
• the external wall of the peripheral longitudinal feed channel is connected to the front front wall of the corresponding transfer channel by a regular rounded area.
• the inner face with a concave profile of the transfer channel is connected to the corresponding peripheral longitudinal feed channel by a convex rounded zone. This feature also reduces the presence of dead spots, and improves spraying.
• the inner face with a concave profile of the transfer channel is connected to the peripheral wall of the swirl chamber by a convex rounded connection zone.
• the cone angle of the outlet coaxial hole is between 15 ° and 30 °, advantageously about 20 °.
• a better regularity of distribution of droplets at the outlet of the nozzle is also obtained by using transfer channels five in number, distributed regularly around the longitudinal axis of the nozzle. This effect apparently results from the fact that the greater number of channels reduces the duration of the transient spraying establishment regime and makes it possible to reach the steady state more quickly. Compared to a three-channel nozzle, the initial transient regime is reduced, and in particular the spraying angle at the nozzle outlet more quickly reaches the steady-state angle.
• the invention provides a liquid sprayer, which comprises a spray nozzle as defined above.
• a sprayer has advantages for spraying all types of liquids, and it also has advantages in particular when it contains a liquid to be sprayed whose viscosity is between 800 and 1000 mPa.s approximately, and whose density is between 1,000 and 1,100 kg / m 3 approximately. Excellent results are obtained when the sprayer contains a thixotropic liquid.
• FIG. 1 is an overall side view in longitudinal section of a spray nozzle according to a particular embodiment of the invention, comprising a central core engaged in a female nozzle body;
• FIG. 2 is a view of the rear face of the female nozzle body structure of Figure 1;
• FIG. 3 is a diametrical longitudinal section of the female nozzle body structure along the plane C-C of Figure 2;
• FIG. 4 is a rear three-quarter perspective view of the female nozzle body structure
• Figure 5 is a partial rear view of Figure 2, showing on a larger scale the curvature of the faces of the channels;
• FIG. 6 is a general schematic view of a sprayer according to the invention.
• a spray nozzle according to ' 1' invention comprises a nozzle body 1 comprising a cylindrical housing 2 open towards the rear and closed towards the front by a front wall 3.
• a core 4 (figure 1) generally cylindrical with a full front face 5 is engaged coaxially ent in the cylindrical housing 2 of the nozzle body 1, coming to bear on the rear face 6 of the front wall 3.
• the front face 5 can advantageously be bordered by a leave 5a .
• a swirl chamber 7 is thus distinguished, having a general shape of revolution around the longitudinal axis II, limited by a peripheral wall 8, by a rear wall formed by the core 4, and by a front wall 9 pierced with a coaxial outlet hole 10.
• the spray nozzle comprises five oblique transfer channels such as channels 11, 12, 13, 14 and 15.
• the transfer channels 11-15 tangentially inject the liquid into the swirl chamber 7 by rotating it around the axis II, for example in the direction of rotation of the needles of a watch in FIG. 2.
• Five peripheral longitudinal supply channels such as channels 16, 17, 18, 19 and 20 conduct the liquid from a liquid inlet 40 and inject it into a respective transfer channel 11-15.
• the transfer channels 11-15 are distributed equitably around the swirl chamber 7 and have the same shape, so that the spray nozzle has symmetry about the longitudinal axis I-I. We will therefore describe the shape of only one of the transfer channels. This shape is as shown to scale in Figures 2, 4 and 5, which may be referred to for more details.
• the transfer channel 11 is limited by an external face 21 and by an internal face 22: the external face 21 is the face furthest from the longitudinal axis II, while the internal face 22 is the side closest to the longitudinal axis II.
• the outer face 21 has a generally rectilinear profile and is connected tangentially along the connection zone 23 to the peripheral wall 8 of the swirl chamber 7.
• the inner face 22 of the transfer channel 11 has a concave profile L1 over most of its length.
• the inner face 22 with concave profile L1 may be generally circular according to a radius advantageously between one and a half and two times the radial distance DR between the corresponding peripheral longitudinal feed channel 16 and the swirl chamber 7.
• the inner face 22 with a concave profile L1 of the transfer channel 11 can be connected to the peripheral longitudinal supply channel 16 by a convex rounded zone 24.
• the external face 21 with a generally rectilinear profile of the transfer channel 11 can be connected to the peripheral longitudinal supply channel 16 by a convex rounded zone 25.
• the inner face 22 with concave profile L1 of the transfer channel 11 can be connected to the peripheral wall 8 of the swirl chamber 7 by a rounded convex connection zone 26 with a small radius.
• the radius of curvature of the convex connection zone 26 can be between approximately 50 microns and 80 microns.
• the coaxial outlet hole 10 can advantageously be centered on the longitudinal axis I-I with a tolerance of less than
• the exit coaxial hole 10 can be aligned on the longitudinal axis I-I with a deviation tolerance of less than approximately 4 °.
• the coaxial outlet hole 10 according to the invention is conical, converging downstream or towards the outlet of the nozzle.
• the cone angle A of the outlet coaxial hole 10 is between approximately 15 ° and 30 °, advantageously approximately 20 °.
• the coaxial outlet hole 10 is conical over most of its length from the inlet port.
• the coaxial outlet hole 10 can be connected to the external face of the anterior wall 3 by a leave or an O-ring surface, without affecting spray performance.
• the cross section of the first transfer channels 11-15 can advantageously be reduced progressively from the peripheral longitudinal supply channel towards the swirl chamber 7.
• the interior and exterior faces can make an angle B of approximately 15 °.
• Their anterior (in the anterior wall 3) and posterior (anterior face 5 of the core 4) faces may advantageously be parallel, to facilitate manufacture thereof.
• the external wall of the peripheral longitudinal supply channel 16 is connected to the front front wall of the corresponding transfer channel 11 by a regular rounded zone 16a.
• the flow of the fluid is improved by reducing its disturbances in the zone upstream from the transfer channels and from the swirl chamber.
• the acceleration of the fluid takes place gradually from the inlet 40 of the nozzle to the outlet from the coaxial outlet hole 10. This promotes the spraying of all types of liquids, in particular thixotropic liquids.
• the channel shapes are entirely produced in the nozzle body, the core 4 being simply cylindrical, possibly with a leave 5a. This facilitates the manufacture of the nozzle, making it possible to mass produce small diameter nozzles for cosmetic applications.
• the shape of the nozzle according to the invention produces a dynamic spraying effect: depending on the pressure, the fractionation of the droplets remains satisfactory, but their distribution is modified in the spray cone.
• the pressure is low, the droplets tend to concentrate in the center of the spray cone, while at higher pressures the droplets tend to distribute themselves around the periphery of the cone.
• the pressure begins with low values, then gradually increases, then decreases to low values. The result that the droplets are first concentrated towards the center of the spray cone, then concentrated around the periphery and finally concentrated again at the center, so that the average distribution of the droplets is substantially constant in the spray cone at the end of the spray sequence.
• the nozzle structure thus defined promotes the acceleration of the fluid inside the channels and in the swirl chamber, thus producing at the outlet of the nozzle a spraying with particularly fine droplets, the size of which is at least 30% smaller. compared to the droplets obtained by known spray nozzles.
• the general dimensions of the spray nozzle according to the invention can be chosen as a function of the desired flow rate of liquid.
• a liquid sprayer 27 comprises a container 28, a pump 29 and a spray nozzle 30 as defined above.
• the pump 29 is actuated which sucks the liquid 32 from the container 28 by a dip tube 33 and injects it under pressure into the spray nozzle 30 which produces, at the outlet, a spray cone 34.
• the particular structure of the spray nozzle 30 according to the invention allows the correct operation of such a sprayer 27 containing a liquid 32 to be sprayed, the viscosity of which may be greater than that of water, which may be between 800 and 1000 mPa .s approximately, and whose density is between 1000 and 1100 kg / m 3 approximately.

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• 2002
  • 2002-01-25 FR FR0201116A patent/FR2835203B1/fr not_active Expired - Fee Related
• 2003
  • 2003-01-24 EP EP20030700410 patent/EP1467818A1/de not_active Withdrawn
  • 2003-01-24 WO PCT/IB2003/000188 patent/WO2003061839A1/fr not_active Application Discontinuation

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