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 swirl chamber and then leaves the central swirl chamber by 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 pusher gas, in particular for spraying cosmetic products.
• spray nozzles described in particular in document EP 0 000 688 A, 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 rectilinear profile and 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 reduced gradually from the coaxial circular channel to the swirl chamber.
• Such spray nozzles work well for spraying low viscosity liquids such as water, producing droplets of satisfactory size, on the order of 90 microns.
• the problem proposed by the present invention is to reduce the size of the droplets sprayed at the outlet of a nozzle supplied with medium viscosity liquid or supplied with gel.
• 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, at least one coaxial circular channel arranged around the swirl chamber and communicating with said swirl chamber by a plurality of first oblique transfer channels injecting the liquid in rotation in a direction of rotation into the swirl chamber,
• the first transfer channels are each limited by an outer face with a generally rectilinear profile and tangentially connecting to the peripheral wall of the swirl chamber,
• the first transfer channels are each limited by an inner face having a concave profile over most of its length.
• the droplet sizes sprayed at the outlet of the nozzle are significantly smaller than those obtained by the nozzles of the prior art mentioned above. It is estimated that we gain about 30% on the size of the droplets sprayed at the outlet.
• the average diameter of the droplets can be between approximately 95 microns and approximately 65 microns.
• a side 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 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 about 80 microns, for liquids whose viscosity is between 800 and 1000 mPa. s.
• the inner face with a concave profile of the first transfer channel is generally circular according to a radius of between one and a half and two times the radial distance DR between the coaxial circular channel and the swirl chamber. This reduces the presence of dead zones, that is to say zones in which the liquid takes a slow speed in the spray nozzle, and the spraying is improved.
• the inner face with concave profile of the first transfer channel is connected to the inner wall of coaxial circular channel by a convex rounded area. This feature also reduces the presence of dead spots, and improves spraying.
• an outer face with a generally rectilinear profile of the first transfer channel which is connected to the inner wall of a coaxial circular channel by a rounded convex zone.
• the invention provides a liquid sprayer, which comprises a spray nozzle as defined above.
• a sprayer 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 1000 and 1100 kg / m 3 approximately.
• FIG. 2 is a cross section on a larger scale along the plane A-A of Figure 1;
• FIG. 3 is an enlarged view of the front region of the spray nozzle of Figure 1, in section along the surface C-C of Figure 2;
• Figure 4 is a partial view of Figure 2, showing on a larger scale the curvature of the channel faces;
• FIG. 5 is a general schematic view of a sprayer according to the invention.
• a spray nozzle according to the 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 generally cylindrical core 4 with a full front face 5 is engaged coaxially in the cylindrical housing 2 of the nozzle body 1, coming to bear on the rear face 6 of the front wall 3.
• 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 at least one coaxial circular channel 11 placed around the swirl chamber 7 and communicating with said swirl chamber 7 by a plurality of first oblique transfer channels such as channels 12, 13, 14 and 15.
• the first transfer channels 12-15 tangentially inject the liquid into the swirl chamber 7 by giving it a rotation about the axis II, for example in the direction of rotation of the needles of a watch in FIG. 2.
• a plurality of second transfer channels such as channels 16, 17, 18 and 19 conduct the liquid from a liquid inlet 20 and inject it tangentially into the coaxial circular channel 11.
• the liquid is in rotation in the same direction of rotation as in the vortex chamber 7, that is to say clockwise in the example of FIG. 2.
• the first transfer channels 12-15 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 first transfer channels. This shape is as shown to scale in Figures 2 and 4, which may be referred to for more details.
• the first transfer channel 14 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 face closest to longitudinal axis II.
• the external face 21 has a generally rectilinear profile and is tangentially connected according to the connection zone 23 to the peripheral wall 8 of the swirl chamber 7.
• the inner face 22 of the first transfer channel 14 has a concave profile L1 over most of its length.
• the inner face 22 with concave profile L1 can be generally circular according to a radius advantageously between one and a half and two times the radial distance DR between the coaxial circular channel 11 and the swirl chamber 7.
• the inner face 22 with concave profile L1 of the first transfer channel can be connected to the interior wall 35 of the coaxial circular channel 11 by a convex rounded zone 24.
• the external face 21 with a generally rectilinear profile of the first transfer channel 14 can be connected to the internal wall 35 of the coaxial circular channel 11 by a convex rounded zone 25.
• the inner face 22 with a concave profile Ll of the first transfer channel 14 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 according to a tolerance of less than approximately 80 microns, preferably less than 60 microns. Likewise, the exit coaxial hole 10 can be aligned on the longitudinal axis I-I with a deviation tolerance of less than approximately 4 °.
• the cross section of the first transfer channels 12-15 can advantageously be reduced progressively from the coaxial circular channel 11 towards the swirl chamber 7.
• Their anterior (in the anterior wall 3) and posterior (anterior face 5 of the core 4) faces advantageously be parallel, to facilitate manufacture.
• 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 approximately 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 is activated 29 which sucks the liquid 32 from the container 28 through 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. Good results can also be obtained when the liquid 32 has thixotropic properties.

Landscapes

• Nozzles (AREA)
• Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)
• Absorbent Articles And Supports Therefor (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (2)

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ID=8860863

Family Applications (1)

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Cited By (18)

Families Citing this family (2)

Citations (7)

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• 2001
  • 2001-03-05 FR FR0103129A patent/FR2821573B1/fr not_active Expired - Fee Related
• 2002
  • 2002-03-04 AT AT02701496T patent/ATE279988T1/de not_active IP Right Cessation
  • 2002-03-04 DE DE60201663T patent/DE60201663D1/de not_active Expired - Lifetime
  • 2002-03-04 WO PCT/IB2002/000658 patent/WO2002070141A1/fr not_active Ceased
  • 2002-03-04 EP EP02701496A patent/EP1365864B1/de not_active Expired - Lifetime

Patent Citations (7)

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