Venturi device with multiple injection openings for atomizing a liquid formula

Description

[Technical Field]

[0001] The present invention relates to an injection system comprising a Venturi device having a multi-injection port for atomizing and injecting liquid formula, such as for example, water, oil, lotion or the like, for a transdermal delivery.[Background Art]

[0002] A liquid formula, such as a liquid lotion including a hyaluronic acid, is typically applied to specific parts of the user's body, such as a face, hands, and arms, via a shallow transdermal delivery (i.e., a shallow depth skin delivery).

[0003] In particular, it has been found through many studies that the transdermal absorption effect is enhanced when 100 m / s or more is achieved by accelerating particles of liquid formula. It is well known from prior arts to use a Venturi tube for atomizing and supplying liquid formula.

[0004] US 4,595,127 discloses an aerosol dispenser having a dispensatory means. The dispensatory means comprises a venturi passage consisting of a pressure vapor entrance cone, a pressure vapor exit cone, a straight section orifice, and at least one tap. The tap is arranged near the straight section orifice to supply product to be mixed with pressure vapor which enters the dispensatory means through the pressure vapor entrance cone.

[0005] JP H06-277481 discloses a mixing device for a foam extinguishing system. The system comprises a venturi conduit having a primary throat, a secondary throat, and a plurality of formulated concentrate orifices. The formulated concentrate orifices are radially arranged between the primary throat and the secondary throat. A diameter D1 of the primary throat is smaller than the diameter D2 of the secondary throat.

[0006] WO 01 / 00308 discloses an apparatus for fluid mixing and dispensing. The apparatus comprises an inwardly tapered portion, throat portion, an outwardly tapered portion, and inlets. The throat portion, the outwardly tapered portion, and a part of the inwardly tapered portion are divided into two venturi passages by a septum. The inlets are aligned diametrically opposite to each other so that the inlet opens into the venturi passage of the throat portion and the inlet opens into the venturi passage of the throat portion.

[0007] US20180099104A1 (Gold NanoTech Inc.) discloses a liquid introducing device transferring a fixed amount liquid into atomized particles. The liquid introducing device comprises a bottle containing liquid and a Venturi tube which is in fluid communication with the bottle. Pressurized gas flows through the Venturi tube and atomizes the liquid contained in the bottle.

[0008] US20110137281A1 (Gold NanoTech Inc.) discloses a drug delivery device for injecting a cosmetic and medical agent. The delivery device comprises a drug delivery pressuring tube having a Venturi tube shape and a container containing drug and in fluid communication with the drug delivery pressuring tube. Pressurized gas flows through the drug delivery pressuring tube and atomizes the liquid contained in the container.

[0009] However, when a Venturi tube with a general injection port was used, a flow instability phenomenon called Karman vortex was observed, and it had a negative effect on the injection of the liquid formula, causing a problem of increasing the particle size or reducing acceleration and mixing ability of the Venturi tube.

[0010] Typically, the Venturi tube has one fluid inlet and one outlet. In order to perform liquid injection and acceleration and mixing at the same time, it is necessary to secure a connection passage through which formula can be injected at the middle point of the Venturi tube, that is, the point where the fluid acceleration and mixing is maximized. Usually the connection passage is located in an acceleration and mixing section of the Venturi or closer to the entry of the fluid. When the flow of the fluid is accelerated, this passage spontaneously induces the liquid to the center of the Venturi tube where the strong pressure and velocity of the fluid causes the induced liquid to decrease in particles and is transferred to the outlet.

[0011] However, when injecting, the result of the injection is uneven especially when injecting a high viscosity liquid. The liquid formula injected through the outlet has a speed of 100 m / s or more, which is expected to have a stronger transdermal absorption capacity of the cosmetic composition. The faster the speed of the injected particles, the more unstable the particle size distribution. This is a well-known phenomenon in fluid dynamics, more specifically, a Karman vortex which has a repeated pattern of swirling vortices, which is responsible for the unsteady separation of flow of a fluid around obstacle in the flow direction. In the Venturi system, the single liquid injection port acts as the obstacle, and the result of the injection generates Karman vortex.

[0012] It is an object of the present invention to improve the performance of a Venturi tube resulting in improving the stability of injection performance. In particular, it is an object of the present invention to improve the atomization performance using a cosmetic formula having high viscosity (such as over 0.5 Pa·s).[Disclosure of Invention]

[0013] In order to accomplish the object mentioned above, the present invention provides an injection system as recited in claim 1.

[0014] The injection system comprises a Venturi device and a reservoir with a single interior space containing a liquid formula to be injected, the Venturi device comprises: a longitudinal central axis; a mounting flange on which the reservoir containing liquid formula is detachably mounted in a liquid-tight manner; and an internal passage extending along the longitudinal central axis, the internal passage comprising: a converging section comprising an inlet with an inner diameter and an outlet with an inner diameter respectively located on each of two ends thereof; a diverging section comprising an inlet with an inner diameter and an outlet with an inner diameter respectively located on each of two ends thereof; and an acceleration and mixing section comprising an inlet with an inner diameter and an outlet with an inner diameter respectively located on each of two ends thereof; wherein the outlet of the converging section is connected to the inlet of the acceleration and mixing section, and the outlet of the acceleration and mixing section is connected to the inlet of the diverging section, characterized in that two or more injection ports are formed in the mounting flange, which penetrate the mounting flange into the internal passage, the internal passage being thereby in fluid communication with the interior space of the reservoir via the injection ports and that the liquid formula has a viscosity of at most 0.5 Pa·s and that the two or more injection ports are aligned in a direction perpendicular to the longitudinal axis. The size of the inner diameter of the inlet can be 0.1 to 3 mm, preferably 0.3-0.6 mm.

[0015] In one embodiment according to the present invention, the injection ports penetrate into the acceleration and mixing section, and the two or more injection ports are aligned in a direction perpendicular to the longitudinal central axis.

[0016] In one embodiment according to the present invention, a ratio of the inner diameter of the inlet of the converging section: the inner diameter of the acceleration and mixing section: the inner diameter of the outlet of the diverging section is 2:1:2 to 3:1:3. The inner diameter of the converging section linearly or exponentially decreases from the inlet to the outlet, and wherein the inner diameter of the diverging section linearly or exponentially increases from the inlet to the outlet.

[0017] The present invention also provides an injection system comprising: the Venturi system mentioned above; a reservoir containing a liquid formula to be injected and in communication with the internal passage of the Venturi system; and a device coupled to and supplying pressurized gas to the inlet of the converging section of the Venturi system.

[0018] In one embodiment according to the present invention, the device comprises a gas reservoir containing pressurized gas or a cylinder and a piston arranged and slidable in the cylinder to pressurize the gas to be supplied to the Venturi system.

[0019] In one embodiment according to the present invention, the piston is driven by means of an electrical motor. The pressurized gas is air, CO 2 , N 2 , N 2 O, NO, O 2 , or non-toxic gas with bioavailability.[Brief Description of the Drawings]

[0020] The present invention can be better understood upon reading the following description of non-limiting embodiments thereof, and upon examining the accompanying diagrammatic drawings, in which: Figure 1 shows a cross sectional view along a longitudinal central axis of an embodiment of a Venturi device according to the present invention; Figure 2 shows a plan view of the Venturi device according to the present invention; Figure 3 shows a cross-sectional view of an injection system with the Venturi device according to the present invention; Figure 4a shows a plan view of the Venturi device used in a performance test. Figure 4b shows a cross-sectional view along the section A-A in Figure 4a. Figure 5a shows a schematic view of the system used in the performance test. Figure 5b shows a result of particle velocity measured at two points when using the Venturi device in the prior art; Figure 5c shows a result of particle velocity measured at two points when using the Venturi device according to the present invention; Figure 5d shows a result of frequency of distribution with respect to particle diameter and cumulative volume thereof when using a Venturi device in the prior art; and Figure 5e shows a result of frequency of distribution with respect to particle diameter and cumulative volume thereof when using the Venturi device according to the present invention. [Description of Embodiments]

[0021] Some exemplary embodiments of the present invention will now be described with reference to Figures. 1 to 5e. In each figure, the scale ratio of width, length, height, diameter or the like of each element may not be constant, and may be different from the actual one. It should be noted that in certain figures, certain elements or features are drawn larger or smaller than they actually are, for emphasis.

[0022] Figure 1 schematically illustrates a cross sectional view along a longitudinal central axis X 1 of an embodiment of a Venturi device 100 according to the present invention with a liquid reservoir 200 containing liquid formula L to be injected. Figure 2 schematically illustrates a plan view of the Venturi device 100. The Venturi device 100 comprises a mounting flange 160 on which the liquid reservoir 200 is detachably mounted in a liquid-tight manner by a suitable means. The reservoir 200 may comprise a flange 210 on the opening side thereof, which corresponds to the flange 160 of the Venturi device 100. As an example, but not limited to this, the liquid reservoir 200 can be threadably mounted on the mounting flange 160. Any other suitable attachment can be employed.

[0023] The Venturi device 100 comprises an internal passage 110 continuously extending along the longitudinal central axis X 1 . As illustrated in Figure 1, the internal passage 110 comprises a converging section 130, a diverging section 140, and an acceleration and mixing section 150, which are connected continuously along the longitudinal central axis X 1 . The acceleration and mixing section 150 is arranged between the converging section 130 and the diverging section 140.

[0024] The converging section 130 has an inlet 132 and an outlet 134 respectively located on each end thereof. The acceleration and mixing section 150 also has an inlet 152 and an outlet 154 respectively located on each end thereof. Furthermore, the diverging section 140 has an inlet 142 and an outlet 144 respectively located on each of two ends thereof. The outlet 134 of the converging section 130 is connected to the inlet 152 of the acceleration and mixing section 150 smoothly and continuously. Similarly, the outlet 154 of the acceleration and mixing section 150 is connected to the inlet 142 of the diverging section 140 smoothly and continuously.

[0025] The inlet 132 and the outlet 134 of the converging section 130 have an inner diameter (maximum inner diameter) D 1 and an inner diameter (minimum inner diameter) D 4 , respectively. Similarly, the inlet 142 and the outlet 144 of the diverging section 140 have an inner diameter D 5 (minimum inner diameter) and an inner diameter (maximum inner diameter) D 2 , respectively. The inner diameter of the converging section 130 linearly decreases from the inlet 132 to the outlet 134, while the inner diameter of diverging section 140 linearly increases from the inlet 142 to the outlet 144 in this embodiment. However, the inner diameters of the converging section 130 and diverging section 140 may exponentially decrease and increase, respectively.

[0026] The acceleration and mixing section 150 has a constant inner diameter D 3 from the inlet 152 to the outlet 154 in this embodiment. Accordingly, in this embodiment, the inner diameter D 4 of the outlet 134 of the converging section 130 is the same as the inner diameter D 3 of the acceleration and mixing section 150, and the inner diameter D 5 of the inlet 142 of the diverging section 140 is also the same as the inner diameter D 3 of the acceleration and mixing section 150. A ratio of D 1 :D 3 :D 2 is preferably 2:1:2 to 3:1:3. Any other ratios can be also employed as needed.

[0027] As best illustrated in Figure 2, two injection ports 120 are formed in a mounting flange 160 and symmetrically arranged with respect to the longitudinal central axis X 1 . That is, the injection ports 120 are aligned in a direction perpendicular to the longitudinal central axis X 1 . Each of the injection ports 120 penetrates the mounting flange 160 into the internal passage 110. Accordingly, the internal passage 110, in particular the acceleration and mixing section 150 is in fluid communication with the liquid reservoir 200 mounted on the mounting flange 160 via the injection ports 120. Two injection ports 120 are formed in this embodiment, while three or more injection ports 120 can be formed.

[0028] Referring to Figure 3, a cross-sectional view of an exemplary embodiment of an injection system 300 comprising the Venturi device 100 according to the present invention is schematically illustrated. The injection system 300 mainly comprises a casing 302, an electrical motor 304, a gear box 306, a cylinder 308, a piston 310, a compression spring 312, a battery 314, an injection nozzle 316, an attachment 318, and a silencer 320.

[0029] The piston 310 is inserted in the cylinder 308 and is slidable backward (away from the injection nozzle 316) and forward (toward the injection nozzle 316) in the cylinder 308. The compression spring 312 is fixed to the casing 302 at one end and is coupled to the piston 310 at the other end. The electrical motor 304 is coupled to the gear box 306, and one gear of the gearbox 306 meshes a rack provided on the piston 310. The motor 304 is powered by the battery 314. The Venturi device 100 is attached to the casing 302 by means of the attachment 318 so that the inlet 132 of the converging section 130 is arranged next to the injection nozzle 316. The silencer 320 is arranged to surround the outlet 144 of the diverging section 140.

[0030] In use, the battery 314 powers the motor 304, and output of the motor 304 is transmitted to piston 310 via the gearbox 306. Rotation of an axis of the motor 304 is converted to a linear backward movement of the piston 310 in the cylinder 308 via the gearbox 306 and the rack provided on the piston 310. The backward movement of the piston 310 compresses the compression spring 312. When the piston 310 moves back to a certain position, the rack disengages from the gearbox 306 resulting in the piston 310 to advance by means of resilient force of the compression spring 312. The advance of the piston 310 compresses air in the cylinder 308, and compressed air is injected into the internal passage 110 via the injection nozzle 316. The compressed air flowing through the internal passage 110 is further accelerated at the acceleration and mixing section 150 and generates negative pressure to draw liquid formula contained in the reservoir 200 into the acceleration and mixing section 150 via the injection ports 120. The liquid formula drawn is atomized by the compressed air and injected from the outlet 144 of the diverging section 140.

[0031] A more detailed configuration and action of the injection system is disclosed in the Japanese Patent Application No. 2020-213550, and the disclosures thereof are incorporated into the present application by reference. Instead of the motor-powered piston, the injection system may use a gas reservoir (shown in Figure 5a) containing pressurized gas. Such as air, CO 2 , N 2 , N 2 O, NO, O 2 , or non-toxic gas with bioavailability may be used for the pressurized gas.

[0032] The inventor implemented the test to confirm the improvement of the Venturi device according to the present invention compared to a Venturi device in prior art. A Venturi device illustrated in Figure 4a and 4b is used. The difference between the Venturi device according to the present invention and in the prior art is the number of the injection port. The Venturi device according to the present invention has two injection ports, while the Venturi device in prior art has single injection port.

[0033] The dimension of the Venturi device used in the test is as follows. Length of Venturi Tube: 52.5mm Diameter of Injection Port: 0.3mm Diameter of Acceleration and mixing Section: 3.5mm Diameter of Outlet: 9mm

[0034] The liquid used is a mixture of water and a formula including 1% of hyaluronic acid solution with 0.7% of phenoxyethanol. The viscosity of the liquid is 3.37 Pa·s. Input gas is CO 2 , Air, Nitrogen, or any other gas which does not interact with cosmetic ingredients or formulae. Input gas pressure is 1 to 10 bar.

[0035] Figure 5a schematically illustrates the model measuring velocity of the fluid injected. Point 1 is located at a radial and longitudinal center of the acceleration and mixing section to which the liquid is supplied from the reservoir. Point 2 is located at a radial center of the outlet.

[0036] Figures 5b and 5c respectively illustrate graphs showing variations of velocity of the liquid versus duration time of injection, in which the duration time is plotted on a transverse axis and the velocity of the liquid is plotted in a vertical axis. Figure 5b shows the result when using a Venturi device having single injection port, while Figure5c shows the result when using a Venturi device having two injection ports. The inventor observed the result that the Venturi device having two injection ports can obtain more stable velocity of the liquid than that of the Venturi device having a single injection port.

[0037] Figures 5d and 5e illustrate graphs showing fluctuations of the particle diameter of the liquid. Figure shows the result when using a Venturi device having single injection port, while Figure5e shows the result when using a Venturi device having two injection ports. In addition, Table 1 shows an average diameter in the cumulative volume distribution of the particle diameter. "Dv10 (small 10%)" in Table 1 means 10th percentile of the cumulative volume distribution, which is a size below which there is 10% of the volume of the sample, so it is used to track changes to the finest particles in population. "Dv50 (small 50%)" in Table 1 means 50th percentile counted from the fine side of the cumulative volume distribution. "Average_D66%" in Table 1 means an average of middle 66% of particle diameter in the cumulative volume distribution. "Gap" indicates percentile of the difference of average diameter between the single port and the two ports with respect to average diameter of the single port. The inventor observed that the Venturi device having two injection ports can obtain finer particles than the Venturi device having single injection port. Table 1Dv10 (small 10%)Dv50 (small 50%)Average_D66%Single Port54.24µm629.4µm138.3µmTwo Ports18.01µm226.6µm46.36µmGap66.6%64.5%66.5%

[0038] Specific data of one example of the Venturi device according to the above described embodiment are listed below. However, the present invention is not limited by these values: Length of the Venturi device: 30-100mm; Inner diameter of the acceleration and mixing section: 3.5mm; Diameter of inlet of the converging section and outlet of the diverging section: 2 to 3 times as large as the inner diameter of the acceleration and mixing section; Diameter of the injection port: 0.1 to 1mm, preferably 0.1 to 0.6mm.

[0039] The preferred embodiments of the present invention have been explained above in detail with referrence to the drawings. However, the present invention is not limited to these embodiments, and various modifications and changes may be made to the above-described embodiments without deviating from the scope of the claims.

Claims

1. An injection system (300) comprising a Venturi device (100) and a reservoir (200) with a single interior space containing a liquid formula (L) to be injected, the Venturi device (100) comprising: a longitudinal central axis (X1); a mounting flange (160) on which the reservoir (200) containing liquid formula (L) is detachably mounted in a liquid-tight manner; and an internal passage (110) extending along the longitudinal central axis (X1), the internal passage comprising: a converging section (130) comprising an inlet (132) with an inner diameter (D1) and an outlet (134) with an inner diameter (D4) respectively located on each of two ends thereof; a diverging section (140) comprising an inlet (142) with an inner diameter (D5) and an outlet (144) with an inner diameter (D2) respectively located on each end thereof; and an acceleration and mixing section (150) comprising an inlet (152) with an inner diameter (D3) and an outlet (154) with an inner diameter (D3) respectively located on each end thereof; wherein the outlet (134) of the converging section (130) is connected to the inlet (152) of the acceleration and mixing section (150), and the outlet (154) of the acceleration and mixing section (150) is connected to the inlet (142) of the diverging section (144), characterized in that two or more injection ports (120) are formed in the mounting flange (160), which penetrate the mounting flange (160) into the internal passage (110), the internal passage (110) being thereby in fluid communication with the interior space of the reservoir (200) via the injection ports (120) and that the liquid formula (L) has viscosity of at most 0.5 Pa·s, and that the two or more injection ports (120) are aligned in a direction perpendicular to the longitudinal central axis (X1).

2. The injection system (300) according to claim 1, wherein the injection ports (120) penetrate into the acceleration and mixing section (150).

3. The injection system (300) according to any one of claims 1 and 2, wherein a ratio of the inner diameter (D1) of the inlet (132) of the converging section (130): the inner diameter (D3) of the acceleration and mixing section (150): the inner diameter (D2) of the outlet (144) of the diverging section (140) is 2:1:2 or larger ratio.

4. The injection system (300) according to any one of claims 1 to 3, wherein the inner diameter of the converging section (130) linearly or exponentially decreases from the inlet (132) to the outlet (134), and wherein the inner diameter of the diverging section (140) linearly or exponentially increases from the inlet (142) to the outlet (144).

5. The injection system (300) according to any preceding claims, comprising: a device coupled to and supplying pressurized gas to the inlet (132) of the converging section (130) of the Venturi device (100).

6. The injection system (300) according to claim 5, wherein the device comprises a gas reservoir containing pressurized gas to be supplied to the Venturi device (100).

7. The injection system (300) according to claim 5, wherein the device comprises a cylinder (308) and a piston (310) arranged to be slidable in the cylinder (308) to pressurize the gas to be supplied to the Venturi device (100).

8. The injection system (300) according to claim 7, wherein the piston (310) is driven by means of an electrical motor (304).

9. The injection system (300) according to any one of claims 5 to 8, wherein the pressurized gas is air, CO2, N2, N2O, NO, O2, or non-toxic gas with bioavailability.