Liquid spray device

Abstract

To provide a liquid spray device which can spray liquid with significantly increased bubble number density in a fine bubble region, particularly in an ultra-fine bubble region using a simple mechanism.SOLUTION: A liquid spray device includes: a container A which stores liquid; a flow path member which guides the liquid in the container to a spray nozzle; a pump which suctions liquid through the flow path member and sprays it from the spray nozzle; and a cavitation processing member 54 which is arranged within the flow path of the flow path member so as to be in contact with the liquid flowing through the flow path by the pump, and has multiple cavitation points where the flow velocity of the liquid is locally increased in a distributed manner on a contact surface with the liquid. The liquid flow cross-sectional area of the flow path at the arrangement position of the cavitation processing member is set to be greater than the flow cross-sectional area of a spray port of the spray nozzle.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a liquid spray device. [Background technology]

[0002] Patent Document 1 discloses an aerial spray microbubble nozzle for spraying microbubble (fine bubble) water into the air. Patent Document 2 discloses an injection product in which a liquid is filled in a container A together with a compressed gas, and a valve mechanism with an injection member is provided. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-100720 A [Patent Document 2] Patent No. 6746382 [Patent Document 3] JP 2004-358284 A [Non-patent literature]

[0004] [Non-Patent Document 1] NanotechJapan Bulletin Vol. 8, No. 4, 2015 Special feature "Collabo Nanotechnology" <4th> Pages 1-6 Summary of the Invention [Problem to be solved by the invention]

[0005] The microbubble nozzle for aerial spraying described in Patent Document 1 requires a nozzle with a special inlet for introducing air. In addition, this nozzle requires a special structure for mixing the introduced air with pressurized water, which is complicated. The same is true for the spray product described in Patent Document 2, which fills liquid together with compressed gas.

[0006] Furthermore, in fine bubble water obtained by this type of pressurized dissolution mechanism, bubbles tend to grow as the pressure is released, making it difficult to increase the number density of fine bubbles that can be retained in the liquid. In particular, it is difficult to ensure a number density of bubbles in the ultra-fine bubble range.

[0007] An object of the present invention is to provide an apparatus capable of spraying a liquid having a significantly increased bubble number density in the fine bubble region, particularly in the ultra-fine bubble region, using a simple mechanism. [Means for solving the problem]

[0008] In order to solve the above problems, the liquid spray device of the present invention comprises a container for storing liquid, a flow path member for leading the liquid in the container to a spray nozzle, a pump for sucking the liquid through the flow path member and spraying it from the spray nozzle, and a cavitation treatment member arranged within the flow path of the flow path member so as to come into contact with the liquid flowing through the flow path by the pump, and having a plurality of distributed cavitation points formed on the contact surface with the liquid that locally increase the flow rate of the liquid, and is characterized in that the liquid flow cross-sectional area of ​​the flow path at the arrangement position of the cavitation treatment member is set larger than the flow cross-sectional area of ​​the spray outlet of the spray nozzle. Effect of the Invention

[0009] According to the present invention, there is provided an apparatus that can spray a liquid having a significantly increased bubble number density in the fine bubble region, particularly in the ultra-fine bubble region, using a simple mechanism. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a liquid treatment device of the present invention. [Diagram 2] 2 is an enlarged cross-sectional view of a press-down head of the liquid treatment device of FIG. 1; [Diagram 3] 2 is an enlarged cross-sectional view showing the periphery of an air cylinder of the liquid treatment device of FIG. 1. [Figure 4] 2 is a cross-sectional view illustrating the operation of the liquid treatment device of FIG. 1. [Diagram 5] FIG. 2 is an enlarged view of the cavitation nozzle of the liquid treatment device of FIG. 1. [Figure 6] FIG. 5 is a longitudinal cross-sectional view. [Figure 7] FIG. 4 is a bottom view showing a first example of an arrangement of a screw member in a communication hole. [Figure 8] FIG. 11 is a bottom view showing a second example of an arrangement of a screw member in a through hole. [Figure 9] FIG. 2 is a schematic diagram illustrating how bubble nuclei in droplets grow into bubbles during spraying. [Figure 10] FIG. 4 is a diagram showing another example of a cavitation nozzle. [Figure 11] 13 is a cross-sectional view showing an embodiment in which a threaded member is threaded directly into the wall of the suction tube. [Figure 12] 12 is a cross-sectional view showing a configuration example of a liquid treatment device using the suction tube of FIG. 11. [Figure 13] 1 is a histogram showing the calculation results of number density by bubble diameter class for Example 1 and Comparative Example 1 in comparison. [Figure 14] 1 is a histogram showing the calculation results of the volume density by bubble diameter class in Example 1 and Comparative Example 1 for comparison. [Figure 15] 11 is a histogram comparing the calculation results of number density by bubble diameter class between Example 2 and Comparative Example 1. [Figure 16] 1 is a histogram showing the calculation results of the volume density by bubble diameter class in Example 2 and Comparative Example 1 for comparison. [Figure 17] 11 is a histogram showing the calculation results of number density by bubble diameter class for Example 3 and Comparative Example 2. [Figure 18] 11 is a histogram showing the calculation results of the volume density by bubble diameter class in Example 3 and Comparative Example 2 for comparison. [Figure 19] 11 is a histogram comparing the calculation results of number density by bubble diameter class between Example 4 and Comparative Example 2. [Figure 20] 11 is a histogram showing the calculation results of the volume density by bubble diameter class in Example 4 and Comparative Example 2 for comparison. [Figure 21]13 is a histogram comparing the calculation results of number density by bubble diameter class in Example 106 and Comparative Example 2. [Figure 22] 13 is a histogram comparing the calculation results of volume density by bubble diameter class in Example 106 and Comparative Example 2. [Figure 23] 13 is a histogram comparing the calculation results of number density by bubble diameter class between Example 118 and Comparative Example 1. [Figure 24] 1 is a histogram showing the calculation results of volume density by bubble diameter class for Example 118 and Comparative Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a cross-sectional view of a liquid spraying device 1 according to an embodiment of the present invention. The liquid spraying device 1 is configured as a spraying device and includes a container A filled with a liquid L, a cylinder member B, and an actuating member C. The container A has a neck 3 standing upright from a cylindrical body 2. The cylinder member B has a small-diameter liquid cylinder 5 extending from the lower part of a large-diameter air cylinder 4, which is suspended into the container A. In the illustrated example, the upper end of the air cylinder 4 is fixed to the mounting cap D. The mounting cap D has a flange-shaped top wall 7 extending inward from the upper end of a peripheral wall 6 fitted to the outer surface of the neck 3 of the container A, and a guide tube 9 standing upright from the inner peripheral part of the top wall 7. The engagement protrusion, which is a hook-shaped cross section and protrudes outward from the upper outer periphery of the air cylinder 4, is fixed in a manner of being fitted into an engagement recess on the lower surface of the top wall 7. A small-diameter liquid cylinder 5 hangs down from the inner circumference of an inward flange-like bottom wall 10 at the lower end of the air cylinder 4, and a suction tube 11 hangs down from the lower end of the cylinder to the bottom of the container body. A cavitation nozzle 50, which will be described later, is detachably attached to the lower end of the suction tube 11.

[0012] The type of liquid L may be water, an aqueous solution (for example, lotion, etc.), an organic solvent such as alcohol, or a mixture thereof, but is not limited to these.

[0013] 2 and 3, the operating member C has a stem 12 that stands up from within the liquid cylinder 5, a push-down head 13 that is fitted onto the upper end of the stem 12, and an air cylinder 4 incorporating a large-diameter cylindrical piston 14. The middle part of the stem 12 is inserted into the center of the large-diameter cylindrical piston 14 that is fitted into the air cylinder 4. The push-down head 13 is provided so as to be movable up and down while being biased upward, and a spray nozzle 15 is provided horizontally within the upper part of the push-down head.

[0014] The spray nozzle 15 is composed of a first member 15a and a second member 15b arranged coaxially. The first member 15a is cylindrical and embedded in the press head 13, and an air outlet path a is formed in the first member 15a, which communicates with the inside of the air cylinder 4 in the axial direction. The second member 15b is fitted into the recess of the press head 13 in a manner that covers the front end side of the first member 15a while forming a small gap 28 (forming a part of the liquid outlet path b), and its front side opens as the spray nozzle 16. A liquid outlet path b is formed on the outside of the spray nozzle 15, which communicates the spray nozzle 16 with the inside of the stem 12. When the operating member C is pressed down as shown in FIG. 12, the liquid outlet path b is negatively pressurized by the air that passes through the air outlet path a and is ejected from the spray nozzle 16, and the liquid in the container is sucked up by the negative pressure and mixed with the ejected air to be sprayed.

[0015] As shown in Figures 2 and 3, a small diameter cylindrical piston 17 is fitted to the inner circumference of the liquid cylinder 5, and a push-down head 13 is fitted to the upper end of a stem 12 that protrudes from the outer circumference of the lower end of the small diameter cylindrical piston 17. The push-down head 13 is formed by horizontally installing a horizontal tube 19 with an open front end on the inner upper part of a casing 18 that is a topped cylindrical opening with a top wall 18b extended from the upper end of a peripheral wall 18a, and a spray nozzle 15 with an outlet opening at its tip is fitted into the horizontal tube 19. The push-down head 13 also includes a vertical inner tube 20 that hangs down with its upper end communicating with the horizontal tube 19 and has its lower end fitted into the upper end of the inner circumference of the stem 12, and a vertical outer tube 21 that hangs down on the outer circumference of the vertical inner tube 20 and hangs down with a gap at the upper end of the outer circumference of the stem 12.

[0016] A base cylinder 14a is provided through the center of the large-diameter cylindrical piston 14 fitted into the air cylinder 4. The upper part of the base cylinder 14a is airtightly fitted into the inner surface of the lower part of the vertical outer cylinder 21 of the push-down head 13 so as to be movable up and down with a small stroke. The stem 12 is urged upward by a coil spring 22 provided in the small-diameter liquid cylinder 5, and this upward urging presses the lower surface of the movable valve body (described later) against the upper surface of the partition wall 14b of the large-diameter cylindrical piston 14, and the lower end surface of the base cylinder 14a against the upper surface of a seat 23 attached to the outer surface of the middle part of the stem 12.

[0017] A partition wall 14b is provided between the base cylinder 14a and the outer peripheral cylinder 14c of the large diameter cylindrical piston 14. The radially middle part of the partition wall 14b is an upright cylinder, and a plurality of outside air intake valve holes 24 are drilled in the partition wall part that contacts the base cylinder 14a. A synthetic resin cylinder 25 is airtightly fitted to the lower outer surface of the base cylinder 14a, and a flange-shaped elastic thin plate 26 is provided on the lower outer surface of the synthetic resin cylinder 25 so as to protrude upward and outward. The outer peripheral edge of the flange-shaped elastic thin plate 26 is pressed against the lower surface of the partition wall 14b outside the outside air intake valve hole 24 to form an outside air intake valve 27.

[0018] The air ejection passage a is configured to communicate with the inside of the spray nozzle 15 by passing from the lower end surface of the base tube portion 14a, between the stem 12 and the base tube portion 14a, between the stem 12 and the vertical outer tube 21, and between the vertical inner tube 20 and the vertical outer tube 21, and further communicate with the spray nozzle 16 through the small gap 28. The liquid outflow passage b is configured to communicate with the spray nozzle 16 by passing from inside the stem 12 through the vertical inner tube 20, through a through hole 29 drilled in the horizontal tube 19, through a gap 30 around the spray nozzle 15, and through the small gap 28. The lower end surface of the base tube portion 14a and the upper surface of the seat 23 form an air ejection valve 31, and a liquid stop valve 32 is provided in the stem 12.

[0019] Also, the stem 12 is provided with an engagement protrusion 33. An upward engagement step is provided on the inner surface of the middle part of the engagement upright plates vertically provided on the inner surface of the lower part of the small-diameter liquid cylinder 5. Meanwhile, the upper part of a rod 34 is inserted into the stem 12. On the outer surface of the lower part of the rod 34, a plurality of engagement protrusions are attached, which fit between the engagement upright plates so as to be movable up and down. The upper end of such rod 34 is semi-spherical with a large diameter part at the upper part, and the upper outer surface of the large diameter part is watertightly engaged with the upper side of the engagement protrusion 33 to form a leakage prevention valve 35. Also, a coil spring 22 is arranged between the lower part of the small-diameter liquid cylinder 5 and the small-diameter cylindrical piston 17 in such a way that the rod 34 is loosely inserted. The lower end of the spring 22 is placed on the engagement step of the engagement upright plate, and urges the operating member C upward via the small diameter cylindrical piston 17, while this upward urging pulls up the rod 34 via the engagement protrusion 33 to a state in which the engagement protrusion is pressed against the lower end surface of the coil spring 22.

[0020] In this embodiment, an air inlet hole h is provided in the air cylinder 4 to prevent negative pressure in the container A when the liquid in the container decreases due to spraying, and a movable valve body E is provided to close the air inlet hole h in an openable and closable manner. When the operating member C moves to the lowest locked state shown in Fig. 4, the movable valve body E is pushed down by the operating member C and moves to a closed state of the air inlet hole h. On the other hand, when the operating member C moves to the highest state shown in Fig. 1, the movable valve body E is pushed up by the large diameter cylindrical piston 14 and moves to an open state of the air inlet hole h, and further, when the operating member C moves up and down to eject liquid, the air inlet hole h is maintained in an open state.

[0021] The movable valve body E has a cylindrical seal portion 42 at its outer periphery fitted to the inner surface of the air cylinder 4 above the large-diameter cylindrical piston 14, and a flange-like wall 43 extending inward from the cylindrical seal portion 42 to a position near the outer periphery of the vertical outer cylinder 21. The flange-like wall 43 is stepped and has a pressing protrusion 44 protruding from its underside. In the normal upward biasing state by the coil spring 22 (elastic member), i.e., in the most elevated state, the pressing protrusion 44 is pushed up by the large-diameter cylindrical piston 14, and is engaged with its upper surface abutting against the lower surface of the top wall 7 of the mounting cap D. At this time, the cylindrical seal portion 42 is located above the outside air introduction hole h.

[0022] In addition, a downward step 45 formed by protruding a rib is provided at a predetermined position on the outer surface of the vertical outer cylinder 21. When the operating member C is pushed down from the uppermost position in Fig. 1 to the lowermost locked state in Fig. 4, the downward step 45 comes into contact with the inner peripheral edge of the upper surface of the flange-like wall 43 of the movable valve body E midway, and the cylindrical seal portion 42 is pushed down to a position where it closes the outside air introduction hole h.

[0023] In the initial state of the spray container 1, the liquid cylinder 5 is empty, and by moving the operating member C up and down several times from the state shown in Fig. 1, the liquid L is sucked in through the cavitation nozzle 50 and the suction tube 11 to fill the liquid cylinder 5. When the operating member C is pressed down from this state, first, the stem 12 descends together with the push-down head 13 relative to the large-diameter cylindrical piston 14, opening the air discharge valve 31, and then the lower end of the vertical outer cylinder 21 of the push-down head 13 comes into contact with the upper surface of the partition wall portion 14b of the large-diameter cylindrical piston 14, and the large-diameter cylindrical piston 14 also descends together with the stem 12 with the air discharge valve 31 open.

[0024] At that time, since the outside air intake valve 27 is closed, the air in the air cylinder 4 is ejected from the spray nozzle 16 through the air ejection passage a and the small gap 28. Since the outer periphery of the small gap 28 is under negative pressure, the liquid outlet passage b communicating with the small gap is also under negative pressure, so that the liquid L in the liquid cylinder 5 is sucked into the small gap 28 through the liquid outlet passage b, and the liquid L sucked into the small gap mixes with the ejected air and is ejected from the spray nozzle 16 as a mist.

[0025] When the push-down head 13 is released, the air ejection stops, and the negative pressure in the small gap 28 is eliminated, so the liquid stop valve 32 closes. In addition, the stem 12 rises before the large-diameter cylindrical piston 14, closing the air discharge valve 31, and then the large-diameter cylindrical piston 14 is also raised to its upper end position by the seat 23, creating a negative pressure in the air cylinder 4. This causes the outside air suction valve 27 to open and suck outside air into the air cylinder. Meanwhile, the liquid L in the container A is sucked into the liquid cylinder 5 through the suction tube 11. At this time, the movable valve body E maintains the state shown in FIG. 1, so the outside air introduction hole h is open, and as the negative pressure occurs due to the decrease in the liquid in the container, outside air is introduced into the container A through the outside air introduction hole h.

[0026] The amount of liquid L sucked in at this time is determined by the speed of air flowing into the cylinder 4 until the large-diameter cylindrical piston 14, which has discharged the air from the cylinder 4 by pressing down one stroke of the press-down head 13, returns from the lower end position in FIG. 4 to the upper end position in FIG. 1. Since the elastic displacement of the coil spring 22 corresponding to the pressing stroke when the press-down head 13 is pressed down to the lower end position is almost constant, it is considered that the rising speed of the large-diameter cylindrical piston 14 is also almost constant due to the elastic restoring force of the coil spring 22 corresponding to the elastic displacement. When the press-down head 13 is pressed continuously by a finger (e.g., the index finger or thumb of the dominant hand) in a natural motion, the operation time required for the pressing stroke of the press-down head 13 and the time to return the finger in preparation for the next press are almost equal. The elastic restoring force of the coil spring 22 is adjusted so that the press-down head 13 returns to the upper limit position within the time it takes to return the finger. To achieve stress-free continuous pressing operations, it is desirable that the time it takes for the press head 13 to return from the lower limit position to the upper limit position be approximately equal to the time for one press stroke of the press head 13 during spraying (= the time for one shot of spraying).

[0027] A liquid spraying device 1 in Fig. 1 with the cavitation nozzle 50 omitted is the same as that disclosed in Patent Document 3. However, the configuration of the liquid spraying device to which the present invention is applied is not limited to this. For example, the liquid spraying device 1 in Fig. 1 is configured to mix the liquid in the container with the sucked air before spraying it from the spray nozzle 16, but a spraying device configured to spray only the liquid from the spray nozzle 16 without mixing it with air may be used.

[0028] Returning to Fig. 1, in the liquid spray device 1, the cavitation nozzle 50, the suction tube 11, the liquid cylinder 5, the stem 12, and the vertical inner cylinder 20 constitute a flow path member that guides the liquid L in the container A to the spray nozzle 15. In addition, the push-down head 13, the air cylinder 4, and the large-diameter cylindrical piston 14 constitute a pump that sucks the liquid L through the flow path member and sprays it from the spray nozzle 15.

[0029] 5 and 6, the cavitation nozzle 50 is configured such that a screw member 54 (made of metal: stainless steel, titanium, or the like) is attached to a resin nozzle body 51 such that a leg portion 54f is exposed inside a through hole 53 formed through the nozzle body 51. In this embodiment, the screw member 54 is disposed such that the leg portion 54f is aligned along the diameter direction of the through hole 53 having a circular cross section.

[0030] The screw member 54 may be screwed into a female threaded hole formed in the nozzle body 51, or may be integrated with the nozzle body 51 by insert molding. Also, as shown in Fig. 10, a plurality of screw members 54 may be arranged in the flow direction within the flow hole 53 of the nozzle body 51. In Fig. 10, two screw members 54 are arranged in a twisted positional relationship in which the axes of the legs 54 form a 90° angle. In order to suppress an increase in pressure loss within the flow path, it is preferable to arrange the legs 54 of the plurality of screw members 54 so that the distance between the inner edges in the flow direction is larger than the nominal diameter of the screw (preferably 1.3 times or more the nominal diameter).

[0031] The flow velocity distribution when liquid is passed through the flow hole 53 tends to increase locally at the thread roots formed in the leg 54f. That is, the thread roots of the screw member 51 function as cavitation points CP. The leg 54f has a screw thread formed in a spiral shape in multiple turns, and as shown in Figs. 7 and 8, in the axial cross section of the flow hole 53, the thread roots appear in the form of multiple arrangements at thread pitch intervals in the axial direction along both radial sides of the leg 54f. The screw member 5 constitutes a cavitation treatment member in which multiple cavitation points CP that locally increase the flow velocity of the liquid are formed in a dispersed manner on the contact surface with the liquid. Note that the cavitation treatment member in the present invention is not limited to a screw member, and can be replaced by, for example, a rod member having uneven portions formed in a dispersed manner on the outer circumferential surface as cavitation points.

[0032] 4 includes a pump that sucks liquid L through a flow path member and sprays it from the spray nozzle 15, and a screw member 54 (cavitation treatment member) that is disposed in a flow hole 53 (flow path) of the flow path member so as to come into contact with the liquid L flowing through the flow hole 53 by the pump, and has a plurality of cavitation points CP that locally increase the flow rate of the liquid formed in a dispersed manner on the contact surface with the liquid L. The liquid flow cross-sectional area of ​​the flow hole 53 at the position where the screw member 54 is disposed (the area of ​​the portion obtained by excluding the projected area of ​​the screw member 54 from the projected area of ​​the circular flow hole 53 in the axial cross-sectional projection shown in FIGS. 7 and 8) is set to be larger than the flow cross-sectional area of ​​the spray port 16 of the spray nozzle 15.

[0033] The inventors have found that the liquid spray device 1 configured in this way has a significantly higher density of bubbles of 1 μm or less (so-called ultra-fine bubbles) in the liquid sprayed from the spray nozzle 16 than in the liquid sprayed using a liquid spray device configured without the screw member 54 (cavitation treatment member). The inventors speculate that the mechanism behind this is as follows.

[0034] By operating the push-down head 13, the liquid L in the container A passes through the cavitation nozzle 50, then passes through the suction tube 11, the liquid cylinder 5, the stem 12, and the vertical inner cylinder 20, and is then guided to the spray nozzle 15, where it is mixed with air and sprayed as a mist from the spray nozzle 16. Here, cavitation points CP (thread valleys) are distributed within the flow hole 53, and the average value of the liquid flow velocity within the flow hole 53 is relatively small, but near the bottom of the V-shaped thread valley, the flow is narrowed and centrifugal force is applied due to the liquid colliding with and detouring against the thread leg 54f with a circular cross section, so the local flow velocity near the bottom of the valley becomes considerably high.

[0035] According to Bernoulli's theorem, the high flow rate region near the bottom of the valley becomes a negative pressure region, and based on the difference in the amount of dissolved air between normal pressure and negative pressure, the dissolved air that has not yet dissolved precipitates due to the reduced pressure, generating bubble nuclei (cavitation). The reduced pressure region where bubble nuclei precipitate is limited to the vicinity of the bottom of the valley, and the liquid flow passes through this region instantaneously, after which the pressure returns to normal, so it is believed that most of the generated bubble nuclei stop growing in the nucleus state. The exact size of the bubble nuclei is unknown, but for example, Non-Patent Document 1 reports that in an image of water treated with a swirling flow type ultra-fine bubble (UFB) generator that was flash frozen and observed with an ultra-high voltage electron microscope, fine spots with an average diameter of 10 nm or less can be seen, for example, at a number density of 8.1 x 10 17 It has been reported that about 100 pieces / cc are observed. Although not discussed in the literature, the inventors believe that the spots shown in the electron microscope photograph are quite likely to be bubble nuclei, judging from their size and number density. The density of bubble nuclei of this size cannot be measured by general ultra-fine bubble measuring devices (for example, laser diffraction particle sizers and nanotrunking measuring devices).

[0036] In this way, it can be considered that the liquid in the container is pretreated by contact with the cavitation treatment member prior to being sprayed from the spray nozzle 16 to generate a considerable amount of bubble nuclei (which do not grow into bubbles). As shown in FIG. 9, when droplets LD containing bubble nuclei BN are mixed with air and sprayed from a small-diameter spray nozzle, the droplets BD are decompressed due to the high flow rate during spraying, and the dissolved air grows into bubbles GB of a size that can be measured using the bubble nuclei BN as seeds. It is considered that the total volume of bubbles GB generated in the droplets LD increases as the density of bubble nuclei BN increases. Therefore, it is considered that by spraying a liquid that has been pretreated by contact with a cavitation treatment member and in which the density of bubble nuclei has been actively increased, the amount of bubbles generated can be significantly increased compared to spraying a liquid that is not pretreated.

[0037] The important point here is that if the density of bubble nuclei formed by the pretreatment becomes excessive, the density of bubbles GB that grow during spraying becomes too high, and adjacent bubbles merge and escape from the droplet, resulting in a decrease in the amount of ultra-fine bubbles that can be held in the droplet. Therefore, in pretreatment using a cavitation treatment member, it is essential to adjust the flow rate so that the density of bubble nuclei formed does not become excessive. In the present invention, the liquid flow cross-sectional area of ​​the flow hole 53 (flow path) at the position where the screw member 54 (cavitation treatment member) is arranged is set to be larger than the flow cross-sectional area of ​​the spray port 16 of the spray nozzle 15. As a result, the flow rate of the liquid in contact with the cavitation treatment member is adjusted to a level at which the formation density of bubble nuclei does not become excessive, and the coalescence and floating of bubbles is suppressed, resulting in an effect of significantly increasing the amount of ultra-fine bubbles generated compared to when liquid is sprayed without the cavitation treatment member.

[0038] Returning to Fig. 4, the suction tube 11 has a first end connected to the suction side of the pump and a second end extending to a position facing the bottom surface inside the container A. In the configuration of Fig. 1, a screw member 54 constituting a cavitation treatment member is attached to the suction tube 11 via the nozzle body 51 of the cavitation nozzle 50. The cavitation treatment member can be incorporated, for example, inside the cap D or the push-down head 13 in Fig. 1, but by attaching it to the suction tube 11 as described above, the structure can be greatly simplified.

[0039] If the cavitation treatment member is not attached to the suction tube 11 in an airtight manner, and the cavitation treatment member is exposed above the liquid surface in the container A, the gas above the liquid surface is sucked into the suction tube 11 through gaps where airtightness is not ensured. At this time, if the sucked gas collides with the cavitation treatment member as bubbles, the cavitation points on the member are covered with bubbles, which leads to the prevention of bubble nucleation. In this case, it is desirable to attach the cavitation treatment member (screw member 54) to the suction tube 11 at a position where it is submerged below the liquid surface when the residual liquid level in the container A is 50% of the full-filled state. In this way, the cavitation treatment member (screw member 54) is submerged in the liquid L in the container A until the residual liquid level decreases to 50% of the full-filled state, and the above-mentioned problems can be effectively prevented. In the configuration of FIG. 4, the cavitation treatment member (screw member 54) is attached to the second end of the suction tube 11, and the cavitation treatment member is arranged to be kept in the liquid until the liquid level further decreases. 6, in this embodiment, the upper end side of the flow hole 53 (flow passage) of the cavitation nozzle 50 is a tapered hole 55, and the second end of the suction tube 11 is press-fitted into the tapered hole 55 (flow hole) of the cavitation nozzle 50. This allows the cavitation nozzle 50 to be easily assembled to the suction tube 11. However, the assembly form of the cavitation nozzle 50 to the suction tube 11 is not limited to this, and for example, a convex portion through which the flow hole 53 is formed may be formed on the cavitation nozzle 50 side, and this convex portion may be press-fitted into the suction tube 11.

[0040] As shown in Fig. 11, the screw member 54 may have legs 54f directly screwed into the wall of the suction tube 11 from the outer circumferential surface side of the wall. In the liquid spray device 100 shown in Fig. 12, by using the suction tube 11 to which the screw member 54 is directly attached, it is not necessary to form the cavitation nozzle separately, and the structure can be further simplified.

[0041] When a screw member 54 is used as a cavitation treatment member, the number of thread roots CP (cavitation points) of the screw member 54 present in the liquid flow cross section of the flow hole 53 (flow passage) at the position where the screw member 54 is disposed is calculated by dividing the number of thread roots by the liquid flow cross section, and the value of the thread root area density is 2 / mm 2 More than 20 pieces / mm 2 The thread groove area density should be 2 / mm or less. 2 If the cavitation treatment member is not provided, the amount of bubble nuclei generated will be insufficient, and the advantage in the amount of ultra-fine bubbles generated will not be as significant as when the liquid is sprayed without the cavitation treatment member. 2 If the pressure exceeds this value, the bubble nuclei will form at an excessively high density, causing significant coalescence and floating of the bubbles, and the advantage in terms of the amount of ultra-fine bubbles produced may no longer be significant.

[0042] As shown in FIG. 4, the liquid spraying device 1 has a pump configured as a manual push pump, and is highly versatile when carried and used by individuals. Such a device is filled with, for example, lotion or alcohol as the liquid L, and the amount sprayed per push is adjusted to, for example, within a range of 0.3 cc to 2 cc. By setting the amount sprayed per push to such a relatively small value, the average flow velocity in the liquid flow cross section of the flow hole 53 (flow path) at the position where the screw member 54 is disposed is adjusted to a relatively small value, and the excessive formation density of bubble nuclei and, in turn, the loss due to the coalescence and floating of bubbles can be suppressed. Note that an electric pump can also be adopted as the pump. In addition, the liquid spraying device 1 is configured to spray a mixed phase flow of liquid and air from the spray nozzle 16, but may be configured to spray only the liquid. In this configuration, the liquid is decompressed when it is ejected at high speed from the spray nozzle 16, and the outside air immediately near the outlet of the spray nozzle 16 is mixed with the liquid flow in a decompressed state to perform atomization, so that the effect of the present invention can be achieved in the same way, except that the size of the droplets after spraying is somewhat larger.

[0043] For example, when the amount of spray per push is in the range of 0.3cc to 2cc, the spray time per push is, for example, 0.2 seconds to 1.5 seconds when an average adult operates the manual push pump with normal force. In this case, the average spray flow rate of the liquid in the liquid spray device 1 is, for example, about 30cc / min to 200cc / min. When the manual push pump is manually operated to obtain such an average spray flow rate, the average flow velocity in the liquid flow cross section of the flow path at the position where the screw member is disposed is, for example, 0.05m / sec to 1.2m / sec. The value of the thread valley number flow density obtained by dividing the number of thread valley portions CP of the screw member 54 present in the liquid flow cross section of the flow hole 53 (flow path) by the value of the average spray flow rate is, for example, 0.08 pieces·min / L to 0.80 pieces·min / L. The effect of increasing the amount of ultra-fine bubbles generated compared to when the liquid is sprayed without the cavitation treatment member is particularly remarkable in the above numerical range.

[0044] The results of various tests carried out to confirm the effectiveness of the liquid spray device of the present invention will be described below. (Test Example 1) As the liquid spraying device for testing, a spraying device with the shape shown in Fig. 1 was prepared. For the main body of the spraying device excluding the cavitation nozzle 50, two types (Spray 1 and Spray 2) were prepared, which differed in the inner diameter of the spray nozzle 16 and the amount of spray per push. Table 1 shows the characteristic values ​​of each spraying device.

[0045] [Table 1]

[0046] Various cavitation nozzles 50 were prepared in the form shown in Fig. 5 and Fig. 6. The screw members used were JIS No. 0 Class 1 pan head screw (coarse pitch), with two types of nominal diameters, M1.4 and M1.0, and one screw. The values ​​of the inner diameter, screw pitch and depth, number of thread roots, cross-sectional area, and area density of the number of thread roots of the flow holes of the nozzle body used are shown in Table 2 together with the type of spray atomizer combined (Table 1). In addition, the liquid flow cross-sectional area at the position where the screw member 54 of the cavitation nozzle 50 is arranged is calculated by image processing, for example, as shown in Fig. 7 and Fig. 8, by subtracting the area of ​​the projected area of ​​the leg portion 54f from the area of ​​the circle corresponding to the flow hole 53. Fig. 7 is a projection diagram when a screw member of M1.4 is used, and Fig. 8 is a projection diagram when a screw member of M1.0 is used (the inner diameter of the flow hole 53 is 2.5 mm). The number of thread roots CP can be counted on these projection diagrams.

[0047] Then, from the spray flow rate and liquid flow cross-sectional area shown in Table 1 for each spray spraying device, the average flow velocity of the liquid in the cross section at the arrangement position of the screw member 54 is calculated. In addition, the value of the thread root number flow density is calculated by dividing the number of thread root portions CP by the spray flow rate.

[0048] A spray atomizer equipped with a cavitation nozzle 50 was filled with pure water (dissolved oxygen (DO: 6 ppm), and 15 cc of treated water sprayed into a beaker was collected by repeatedly manually pressing the press head. The collected treated water was filled into a quartz batch cell, and the bubble number density in the ultra-fine bubble region was measured using a laser diffraction type high-sensitivity fine bubble measurement system (Shimadzu Corporation: SALD-7500 x 10) (Examples 1 to 4). For comparison, similar measurements were also made on treated water sprayed and collected without the cavitation nozzle 50 attached to each spray atomizer (Comparative Examples 1 and 2). The above results are summarized in Table 2.

[0049] [Table 2]

[0050] Furthermore, for each of the examples and comparative examples, the results of calculation of the number density and volume density by bubble diameter class obtained by bubble measurement are summarized in Tables 3 to 8.

[0051] [Table 3]

[0052] [Table 4]

[0053] [Table 5]

[0054] [Table 6]

[0055] [Table 7]

[0056] [Table 8]

[0057] As shown in Table 2, in both cases where spray 1 was used (Examples 1 and 2) and where spray 2 was used (Examples 3 and 4), the measured values ​​of the bubble number density (in the ultra-fine bubble region of 1 μm or less) of the treated water were extremely large values, several times to 17 times or more, compared to the case where a liquid spray device without a cavitation nozzle was used (Comparative Example 1 and Comparative Example 2). It can also be seen that more than 2 billion ultra-fine bubbles / cc were detected in the treated water obtained by the liquid spray devices of Comparative Example 1 and Comparative Example 2 without a cavitation nozzle. This means that a certain amount of bubble nuclei was originally contained in the pure water used due to some cavitation history. However, it is presumed that the density of bubble nuclei in the treated water was dramatically increased by the pretreatment with the cavitation nozzle, and it is considered that this growth during spraying resulted in an overwhelming difference in the bubble number density. The liquid spray device of the Example can increase the volumetric existence rate of the ultra-fine bubble region by more than twice that of the Comparative Example. The results are explained in detail below.

[0058] FIG. 13 is a histogram showing the results of calculating the number density by bubble diameter class in Example 1 and Comparative Example 1, and FIG. 14 is a histogram showing the results of calculating the volume density in Example 1 and Comparative Example 1. The number density histogram comparison in FIG. 13 shows that the distribution peak position in Example 1, which has been subjected to pretreatment with a cavitation nozzle, is shifted to the smaller diameter side than in the case where the cavitation nozzle is not attached (Comparative Example 1). In addition, the volume density histogram comparison in FIG. 14 shows that of the two peaks appearing in the ultra-fine bubble region (bubble diameter: 1 μm or less) and the fine bubble region with a bubble diameter of 5 μm or more, the former has a larger increase ratio than the latter. In other words, this result shows that the pretreatment with a cavitation nozzle has the effect of preferentially increasing bubbles in the ultra-fine bubble region. The volume fraction of the ultra-fine bubble region in Comparative Example 1 is about 4.6 μL / L as shown in Table 7, whereas in Example 1 it is about 31.7 μL / L as shown in Table 3, which is about 7 times that of Comparative Example 1.

[0059] FIG. 15 is a histogram showing the calculation results of the number density by bubble diameter class in Example 2 and Comparative Example 1, and FIG. 16 is a histogram showing the calculation results of the volume density in Example 2 and Comparative Example 1. The distribution peak position in Example 2 is shifted to the smaller diameter side than Comparative Example 1, as in Example 1, but the absolute value of the bubble number density of ultra-fine bubbles is lower than that in Example 1. Also, as is clear from the results in FIG. 16, the increase rate of the peak of the fine bubble region relative to Comparative Example 1 is greater than the increase rate of the peak of the ultra-fine bubble region. Since the thread valley number flow density in Example 2 is higher than that in Example 1, the bubble number density in the ultra-fine bubble region is slightly excessive, and some of them may have merged to increase the bubble number density in the fine bubble region. The volume fraction of the ultra-fine bubble region in Example 2 is about 13.2 μL / L from Table 4, which is about 2.9 times that of Comparative Example 1.

[0060] FIG. 17 is a histogram showing the results of calculating the number density by bubble diameter class in Example 3 and Comparative Example 2, and FIG. 18 is a histogram showing the results of calculating the volume density in Example 3 and Comparative Example 2. The number density histogram comparison in FIG. 17 shows that the distribution peak position in Example 3 is shifted to the smaller diameter side than in Comparative Example 2. The volume density histogram comparison in FIG. 18 shows that of the two peaks appearing in the ultra-fine bubble region and the fine bubble region, the former has a larger increase ratio than the latter. That is, it is supported that the pretreatment using the cavitation nozzle has the effect of preferentially increasing the bubbles in the ultra-fine bubble region, as in Example 1. The volumetric abundance ratio of the ultra-fine bubble region in Comparative Example 2 is about 1.9 μL / L from Table 8, while in Example 3 it is about 40.6 μL / L from Table 5, which is about 21 times that of Comparative Example 2.

[0061] Fig. 19 is a histogram showing the calculation results of number density by bubble diameter class for Example 4 and Comparative Example 2, and Fig. 20 is a histogram showing the calculation results of volume density for Example 4 and Comparative Example 2. The comparison of number density histograms in Fig. 19 shows that the distribution peak position in Example 4 is shifted to the smaller diameter side than in Comparative Example 2. Also, the comparison of volume density histograms in Fig. 20 shows that of the two peaks appearing in the ultra-fine bubble region and the fine bubble region, the increase rate of the former is larger than that of the latter, which supports the idea that pretreatment using a cavitation nozzle has the effect of preferentially increasing bubbles in the ultra-fine bubble region.

[0062] (Test Example 2) The same two types of spray spraying devices as in Test Example 1 were prepared, and two types of cavitation nozzles with nominal diameters of M1.4 and M1.0 were used, while the inner diameter, thread pitch and depth, number of thread grooves, cross-sectional area, and thread groove area density of the nozzle body were further set in various ways, and the treated water was evaluated in the same manner as in Test Example 1. In this Test Example 2, a cavitation nozzle with two screw members 54 (distance between inner edges of legs 54f: 2 mm) assembled in the form of Figure 10 was also used for the test. In addition, two types of pure water were used, one with a dissolved oxygen content of 8 ppm and the other with a dissolved oxygen content of 6 ppm. The above results are summarized in Table 9.

[0063] [Table 9]

[0064] The results show that the water treated by the liquid spraying device equipped with the cavitation nozzle has a higher bubble number density in the ultra-fine bubble region than the water treated by the liquid spraying device of Comparative Example 1 or Comparative Example 2 in Table 2, both of which are not equipped with a cavitation nozzle. In particular, when pure water with a dissolved oxygen content of 6 ppm is used, the bubble number density is found to be particularly high under conditions where the thread valley number flow density is 0.80 bubbles min / L or less.

[0065] In addition, for Examples 106 and 118, which have particularly high bubble number densities, the calculation results of number density and volume density by bubble diameter class obtained by bubble measurement are summarized in Tables 10 and 11.

[0066] [Table 10]

[0067] [Table 11]

[0068] FIG. 21 is a histogram showing the results of calculating the number density by bubble diameter class in Example 106 and Comparative Example 2, and FIG. 22 is a histogram showing the results of calculating the volume density in Example 106 and Comparative Example 2. The number density histogram comparison in FIG. 21 shows that the distribution peak position in Example 106 is slightly shifted to the smaller diameter side than in Comparative Example 2. Also, the volume density histogram comparison in FIG. 22 shows that of the two peaks appearing in the ultra-fine bubble region and the fine bubble region, the former has a larger increase ratio than the latter. In other words, it is supported that the pretreatment using the cavitation nozzle has the effect of preferentially increasing the bubbles in the ultra-fine bubble region. From Table 10, the volumetric abundance ratio of the ultra-fine bubble region in Example 106 is about 43.6 μL / L, which is about 22.9 times that of Comparative Example 2 (about 1.9 μL / L).

[0069] FIG. 23 is a histogram showing the results of calculating the number density by bubble diameter class in Example 118 and Comparative Example 1, and FIG. 24 is a histogram showing the results of calculating the volume density in Example 118 and Comparative Example 1. According to the number density histogram comparison in FIG. 23, it can be seen that the distribution peak position in Example 4 is shifted to the smaller diameter side than in Comparative Example 1. Also, according to the volume density histogram comparison in FIG. 24, of the two peaks appearing in the ultra-fine bubble region and the fine bubble region, the former has a larger increase ratio than the latter, which supports the fact that the pretreatment using the cavitation nozzle has the effect of preferentially increasing the bubbles in the ultra-fine bubble region. From Table 11, the volumetric abundance ratio of the ultra-fine bubble region in Example 118 is about 31.6 μL / L, which is about 6.9 times that of Comparative Example 1 (about 4.6 μL / L). [Explanation of symbols]

[0070] 1,100 Liquid spray equipment 5 Liquid Cylinders 4 Air Cylinders 11 Suction tube 12 Stem 13 Pressing head 14 Large diameter cylindrical piston 15 Spray nozzle 20 Vertical inner cylinder 50 Cavitation Nozzle 54 Screw components (cavitation treatment components) A container L liquid CP Thread root (cavitation point)

Claims

1. A liquid spray device comprising: a container for storing liquid; a flow path member for leading the liquid in the container to a spray nozzle; a pump for sucking the liquid through the flow path member and spraying it from the spray nozzle; and a cavitation treatment member arranged within the flow path of the flow path member so as to come into contact with the liquid flowing through the flow path by the pump, and having a plurality of distributed cavitation points formed on the contact surface with the liquid that locally increase the flow rate of the liquid, wherein the liquid flow cross-sectional area of ​​the flow path at the arrangement position of the cavitation treatment member is set larger than the flow cross-sectional area of ​​the spray port of the spray nozzle.

2. The cavitation treatment member is a threaded member whose thread root portion functions as the cavitation point, the thread pitch and thread root depth of the threaded member are both 0.2 mm to 0.4 mm, and the liquid flow cross-sectional area of ​​the flow path at the position where the threaded member is disposed is 2.5 mm ２ More than 15mm ２ 2. The liquid spray device according to claim 1, wherein the inner diameter of the spray nozzle is 0.2 mm or more and 1.0 mm or less.

3. The value of the thread groove area density obtained by dividing the number of thread grooves of the thread member present in the liquid flow cross section of the flow passage at the position where the thread member is disposed by the liquid flow cross section area is 2 / mm ２ 20 pieces / mm or more ２ 3. The liquid spray device of claim 2, wherein:

4. 3. The liquid spray device according to claim 2, wherein the pump is a manual push pump, and the amount of liquid sprayed per one push is 0.3 cc or more and 2 cc or less.

5. A liquid spray device as described in claim 4, wherein when the manual push pump is manually operated so that the average spray flow rate of the liquid is 30 cc / min or more and 200 cc / min or less, the average flow velocity at the liquid flow cross section of the flow path at the arrangement position of the screw member is 0.05 m / sec or more and 1.2 m / sec or less, and the value of the thread root number flow density obtained by dividing the number of thread roots of the screw member present in the liquid flow cross section of the flow path by the value of the average spray flow rate is 0.08 pieces / min or more and 0.80 pieces / min or less.

6. A liquid spray device described in any one of claims 1 to 5, wherein the flow path member has a suction tube having a first end connected to the suction side of the pump and a second end extending to a position facing the bottom surface within the container, and the cavitation treatment member is attached to the suction tube.

7. 7. The liquid spray device according to claim 6, wherein the cavitation treatment member is attached to the suction tube at a position where it is submerged below the liquid surface when the residual liquid level in the container is 50% of the full level.

8. 8. The liquid spray device according to claim 7, wherein the cavitation treatment member is attached to the second end of the suction tube.

9. The cavitation treatment member is a screw member whose thread root portion functions as the cavitation point, and the screw member is assembled to a resin nozzle body formed separately from the suction tube so that the leg portion of the screw member is exposed in a flow hole formed through the nozzle body to form a cavitation nozzle, and the cavitation nozzle is removably attached to the suction tube.

10. 10. The liquid spray device according to claim 9, wherein the second end of the suction tube is press-fitted into the flow hole of the cavitation nozzle.

11. A liquid spray device as described in claim 6, wherein the cavitation treatment member is a screw member whose thread root portion functions as the cavitation point, and the leg portion of the screw member is screwed directly into the wall of the suction tube from the outer peripheral surface side of the wall.

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