Fine bubble generation device and washing machine including the same

Abstract

To provide a fine bubble generation device capable of generating more fine bubbles by agitating a sucked gas, and to provide a washing machine including the same.SOLUTION: A fine bubble generation device 30 includes a flow passage F formed along a central axis line A in a casing 100. The flow passage F has: a first flow passage 31 formed on an entrance 30a side; a second flow passage 32 formed on an exit 30b side; and a throttle flow passage part 33 formed between the first flow passage 31 and the second flow passage 32. On a peripheral surface of the throttle flow passage 33, a plurality of protrusions 35 protruding toward the central axis line A is provided. On the downstream side of the plurality of protrusions 35, a gas introduction part 39 is connected for introducing the gas supplied from the outside of the casing 100.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a fine bubble generating device and a washing machine equipped with the same. [Background technology]

[0002] Conventionally, as described in Patent Document 1, for example, there is known an apparatus for mixing gas that has been ultrafinely broken down to the nano level with liquid. This apparatus comprises a flow rate acceleration section and a gas suction section within a cylindrical casing. The gas sucked into the gas suction section is sheared in the flow rate acceleration section, and liquid containing ultrafine bubbles is generated. A swirling means (swirling flow forming section) that generates a swirling flow around the axis of the flow path is provided upstream of the flow rate acceleration section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2012 / 105536 Summary of the Invention [Problem to be solved by the invention]

[0004] In the device described in the above Patent Document 1, a swirling means is provided that is twisted with respect to the axis of the flow path, and the entire fluid is swirled around the axis and mixed with the sucked gas. With this structure, the amount of fine bubbles generated tends to be insufficient.

[0005] An object of the present invention is to provide a fine bubble generating device capable of agitating sucked gas to generate a larger number of fine bubbles, and a washing machine equipped with the same. [Means for solving the problem]

[0006] [1] One aspect of the present disclosure is a fine-bubble generating device having a flow path formed along a central axis within a casing, the flow path having a first flow path section formed on the inlet side of the casing, a second flow path section formed on the outlet side of the casing, and a throttle flow path section formed between the first flow path section and the second flow path section, the throttle flow path section having a circumferential surface with a plurality of protrusions protruding toward the central axis, and a gas inlet section for introducing gas supplied from outside the casing connected to the downstream side of the plurality of protrusions.

[0007] According to the micro-bubble generator of [1], gas supplied from the outside is introduced into the flow path through the gas inlet section. The introduced gas is self-sucked due to the pressure difference generated by the throttle flow path section. A number of protrusions provided in the throttle flow path section form swirling flows (or vortex flows) of the fluid downstream of the protrusions. The introduced gas is caught in these swirling flows and is mixed with the fluid, resulting in micronization. This makes it possible to generate a larger number of micro-bubbles in the fluid.

[0008] [2] In the micro-bubble generator of [1] above, the radius from the central axis of the central flow passage defined by the tips of the multiple protrusions may be greater than the height to which each of the multiple protrusions protrudes. With this configuration, the height of each protrusion is suppressed, and the cross-sectional area of ​​the central flow passage is ensured. This makes it possible to generate multiple swirling flows only near the circumferential surface without impeding the main flow of the fluid.

[0009] [3] In the micro-bubble generating device of the above [1] or [2], the gap between two adjacent protrusions in the circumferential direction may be wide enough to generate a swirling flow corresponding to each protrusion. With this configuration, a swirling flow corresponding to each protrusion can be reliably generated, and a more suitable stirring effect can be obtained.

[0010] [4] In the micro-bubble generator according to any one of the above [1] to [3], each of the plurality of protrusions may include a triangular pyramid-shaped portion having an apex located on the upstream side. With this configuration, the fluid flow passes over the side surface of the triangular pyramid-shaped portion, and a swirling flow is easily generated on the downstream side of each protrusion.

[0011] [5] As one aspect of the present disclosure, a washing machine may be provided that includes an outer tub arranged in a housing, a fine bubble generator of any one of [1] to [4] attached to the outer tub and having an outlet facing the inside of the outer tub, and a gas supply device provided in the housing for supplying gas to the gas inlet. According to this washing machine, water is supplied to the casing, and water containing a large amount of fine bubbles is collected in the outer tub from the outlet. The dissolution rate of the gas (e.g., air or ozone) is improved, and the efficiency of washing and rinsing is improved. Effect of the Invention

[0012] According to the present invention, the sucked gas can be agitated to generate a larger number of fine bubbles. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a cross-sectional view showing a drum-type washing machine according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a front view showing a fine bubble generating device attached to the outer tub in the drum type washing machine of FIG. [Diagram 3] FIG. 3 is a cross-sectional view including the central axis of the fine bubble generating device. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 5 is an enlarged view of the area around the central axis of FIG. 4, showing the relationship between the radius of the central flow passage portion and the height of each protrusion. [Figure 6] FIG. 6 is a conceptual diagram showing a swirling flow generated by a protrusion provided on the peripheral surface of the throttle flow passage portion. [Figure 7] FIG. 7 is a conceptual diagram showing the positions of a plurality of swirling flows generated corresponding to each protrusion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The same elements are given the same reference numerals, and duplicated explanations will be omitted. The dimensional ratios of the drawings do not necessarily match those in the description.

[0015] In the following description, the mutually orthogonal X, Y and Z directions shown in FIG. 1 or FIG. 2 may be used to describe the washing machine 1. The X and Z directions correspond to the front-rear and height directions (or up-down or vertical directions) in the installed state of the washing machine 1 shown in FIG. 1. The direction perpendicular to the paper surface of FIG. 1 is the Y direction shown in FIG. 2, which corresponds to the left-right direction in the installed state of the washing machine 1. In this specification, terms indicating directions such as "front", "rear", "up", "down", "left", and "right" are terms based on the installed state of the washing machine 1. Furthermore, the terms "upstream" and "downstream" in relation to the fine-bubble generator are terms based on the flow of fluid in the flow path F.

[0016] First, with reference to FIG. 1, the overall configuration of a washing machine 1 according to the first embodiment will be described. The washing machine 1 is, for example, a drum type washing machine. The washing machine 1 includes, for example, a rectangular parallelepiped housing 2. The shape of the housing 2 can be changed as appropriate. A circular door 3 that can be opened and closed is attached to the front of the housing 2. A circular input port 4 through which laundry is input is formed in the front of the housing 2. The input port 4 is opened and closed by the door 3.

[0017] An outer tub 6 and a drum (washing tub) 7 are disposed within the housing 2. Both the outer tub 6 and the drum 7 are cylindrical with a bottom. The outer tub 6 is elastically supported within the housing 2 by a plurality of dampers 11 and springs 12 (not shown). The drum 7 is rotatably disposed within the outer tub 6. The outer tub 6 and the drum 7 are disposed concentrically (coaxially) with respect to a central axis extending in the X direction, for example. The outer tub 6 has a circular opening 6a located in front of the opening 7a of the drum 7.

[0018] The peripheral portion of the opening 6a of the outer tub 6 and the peripheral portion of the input port 4 of the housing 2 are connected by an annular packing 8 made of an elastic material. The packing 8 is fastened and fixed to the outer tub 6 and the input port 4 from the outer periphery side by, for example, a wire or the like. The cross-sectional shape of the packing 8 may be set appropriately. The packing 8 may have a convex portion that protrudes into the gap between the peripheral portions in its cross-sectional shape, or may have an S-shaped cross-sectional shape that combines a convex portion and a concave portion. The peripheral surface of the closed door 3 comes into contact with the packing 8, and the gap between the input port 4 and the door 3 is water-sealed.

[0019] Laundry is stored inside drum 7. A large number of dewatering holes 7b are formed on the inner peripheral surface of drum 7. A balancer 7c is further provided at the front of the inner peripheral surface of drum 7, and a plurality of (e.g., three) baffles 7d are provided at equal intervals in the circumferential direction.

[0020] A drive motor 9 for rotating the drum 7 is installed in the housing 2 and behind the outer tub 6. The drive motor 9 is, for example, an outer rotor type DC brushless motor. A rotating shaft 9a of the drive motor 9 extends in the X direction and is connected to a part of the drum 7. The rotating shaft 9a and the drum 7 may be connected via a pulley or a reduction mechanism, or may be directly connected. During the washing and rinsing steps, the drive motor 9 rotates the drum 7 at a relatively low rotation speed such that the centrifugal force applied to the laundry in the drum 7 is smaller than gravity and the laundry tumbles. During the spin-drying step, the drive motor 9 rotates the drum 7 at a relatively high rotation speed such that the centrifugal force applied to the laundry in the drum 7 is larger than gravity and the laundry sticks to the inner circumferential surface of the drum 7.

[0021] A water supply pipe 13 and a water supply valve 14 are disposed at the rear of the housing 2. The water supply pipe 13 may be a flexible hose, or may be made of a piping material other than a hose. When the water supply valve 14 is opened, tap water from a water faucet is supplied into the outer tub 6 through the water supply pipe 13. The outer tub 6 is capable of storing wash water. In this specification, "wash water" refers to a liquid corresponding to each process, such as the washing process and the rinsing process, of the laundry. Therefore, in the washing process, the wash water may be water (liquid) containing detergent, etc., and in the rinsing process, the wash water may be water. In the rinsing process, the wash water may also contain fabric softener.

[0022] The lower part of the outer tub 6 is formed with a recessed portion 6b recessed downward. A drain pipe 16 is connected to the recessed portion 6b. The drain pipe 16 has, for example, a first drain pipe 16a and a second drain pipe 16b. The first drain pipe 16a and the second drain pipe 16b may be flexible hoses or may be made of piping materials other than hoses. The drain pipe 16 drains the washing water in the outer tub 6. The washing water is drained by gravity through the drain pipe 16, for example, by arranging the drain pipe 16 facing downward. The second drain pipe 16b extends, for example, to the outside of the washing machine 1 (downward). The washing water discharged from the washing machine 1 through the first drain pipe 16a and the second drain pipe 16b is drained through a drain outlet provided in a waterproof pan or the like.

[0023] The washing machine 1 includes a drain filter 20 that is provided, for example, in the middle of the drain pipe 16 and collects foreign matter contained in the washing water. For example, the drain filter 20 is connected to the downstream end of the first drain pipe 16a and to the upstream end of the second drain pipe 16b. For example, the second drain pipe 16b is provided with a drain valve 17. The first drain pipe 16a, the drain filter 20, and the second drain pipe 16b form a drainage path by gravity. When the drain valve 17 is opened, the washing water flowing down from the outer tub 6 and the first drain pipe 16a is introduced into the drain filter 20, and after passing through the drain filter 20 (after filtration), it is discharged through the second drain pipe 16b.

[0024] Washing machine 1 is equipped with operation buttons operated by a user, and a controller (neither shown) that controls the driving of drive motor 9 described above and the opening and closing of water supply valve 14. The controller performs various operations of washing machine 1 according to a pre-stored program in response to operations by the user. Also, in Fig. 1, a detergent dispenser and (if washing machine 1 is provided with a drying function) various parts related to the drying function such as a heater, fan, duct, etc. are omitted from illustration.

[0025] The washing machine 1 of this embodiment has a function of improving the efficiency of washing and rinsing by adding fine ozone bubbles to the washing water. As shown in Fig. 1 and Fig. 2, the washing machine 1 includes a fine bubble generator 30 attached to, for example, an outer tub 6, and an ozone supplying device (gas supplying device) 40 that supplies ozone gas to the fine bubble generator 30. The fine bubble generator 30 has a casing 100 with a flow path F formed therein, and the casing 100 is attached to the outer tub 6 via, for example, a bracket or the like. The cylindrical casing 100 is installed so as to be oriented vertically, for example. A water supply pipe 13 is connected to an inlet 30a of the casing 100, and an outlet 30b of the casing 100 is, for example, directed downward and slightly protrudes from an inner wall surface 6c of the outer tub 6 (see Fig. 2). The outlet 30b of the casing 100 may be flush with the inner wall surface 6c of the outer tub 6, or may be slightly recessed from the inner wall surface 6c of the outer tub 6. By directing the outlet 30b toward the inside of the outer tub 6, the wash water supplied through the water supply pipe 13 and the fine bubble generator 30 accumulates in the outer tub 6 while containing fine ozone bubbles. The wash water may fall along the inner wall surface 6c of the outer tub 6, or may fall inside the drum 7 through the spin-drying holes 7b of the drum 7. In FIG. 1, parts of the outer tub 6 and the drum 7 are cut away to make it easier to understand the position where the fine bubble generator 30 is installed.

[0026] The ozone supplying device 40 is installed, for example, above the outer tub 6 in the housing 2. The ozone supplying device 40 has a built-in known ozone generator (ozonizer) based on, for example, a discharge method, and generates ozone by receiving power in the washing machine 1. The ozone supplying device 40 is controlled, for example, by the controller. The ozone gas having a predetermined concentration generated by the ozone supplying device 40 is supplied through an ozone supply pipe 41. The ozone supply pipe 41 is connected to the gas supply port 30c of the casing 100. The gas supply port 30c is connected to the gas introduction part 39 (see FIG. 3) of the fine bubble generating device 30. The ozone supplying device 40 supplies ozone to the gas introduction part 39 through the ozone supply pipe 41.

[0027] Next, the detailed configuration of the fine bubble generator 30 will be described with reference to Figs. 3 and 4. As shown in Fig. 3, a flow path F is formed along the central axis A in the casing 100. The casing 100 is made of, for example, resin. The flow path F has a first flow path section 31 formed on the inlet 30a side, a second flow path section 32 formed on the outlet 30b side, and a throttle flow path section 33 formed between the first flow path section 31 and the second flow path section 32. The throttle flow path section 33 is connected to the downstream side of the first flow path section 31, and the second flow path section 32 is connected to the downstream side of the throttle flow path section 33. The first flow path section 31, the throttle flow path section 33, and the second flow path section 32 are concentrically arranged with respect to the central axis A. The casing 100 may be made of metal.

[0028] The first flow path section 31 includes, for example, a cylindrical section 31a and a tapered section 31b located downstream thereof. The cylindrical section 31a has a constant first inner diameter D1. The length of the first flow path section 31 may be appropriately determined so as to regulate the flow of water from the inlet 30a. The throttle flow path section 33 has, for example, a cylindrical shape. The throttle flow path section 33 has a constant throttle inner diameter D3. The throttle inner diameter D3 is smaller than the first inner diameter D1. If the first inner diameter D1 is 15 mm to 20 mm, the throttle inner diameter D3 is about 8 mm to 10 mm. The ratio of the throttle inner diameter D3 to the first inner diameter D1 is, for example, within a range of 40% to 60%. The length of the throttle flow path section 33 may be a length that can generate a pressure difference. The throttle flow path section 33 may be as short as possible under the condition (premise) that a pressure difference is generated. The tapered portion 31b of the first flow path portion 31 extends in a truncated cone shape from an upstream end having a first inner diameter D1 to a downstream end having a throttled inner diameter D3.

[0029] The second flow path section 32 has, for example, a tapered shape. The upstream end of the second flow path section 32 has, for example, the same inner diameter as the constricted inner diameter D3 of the constricted flow path section 33. The inclination angle of the wall surface of the second flow path section 32 may be gentler than that of the tapered section 31b of the first flow path section 31. The length of the second flow path section 32 may be appropriately determined so as to sufficiently obtain the stirring effect by the swirling flow V described later. The downstream end of the second flow path section 32 may have, for example, an inner diameter approximately equal to the first inner diameter D1 of the first flow path section 31. The second flow path section 32 may include a tapered section and a cylindrical section located downstream of the tapered section. The second flow path section 32 may include a step section.

[0030] 3 and 4, a peripheral surface 33a of the throttled flow passage section 33 is provided with a plurality of (eight in this embodiment, for example) protrusions 35 protruding toward the central axis A. The plurality of protrusions 35 are provided at the same position in the direction of the central axis A and are equally spaced in the circumferential direction. The plurality of protrusions 35 are molded together with the flow passage F, for example, when the throttled flow passage section 33 (casing 100) is molded. Each protrusion 35 has the same size and shape.

[0031] 6, each protrusion 35 includes a first triangular pyramid portion (triangular pyramid portion) 36 having an apex located on the upstream side, and a second triangular pyramid portion 37 having an apex located on the downstream side. The protrusion 35 has a shape in which a virtual bottom surface located at the downstream end of the first triangular pyramid portion 36 and a virtual bottom surface located at the upstream end of the second triangular pyramid portion 37 are joined together.

[0032] 3 and 6, a single gas introduction part 39 that introduces ozone (gas) supplied from outside the casing 100 is connected to the downstream side of the multiple protrusions 35. The annular gas introduction part 39 is formed so as to communicate the outside of the casing 100 with the inside (flow path F). The gas introduction part 39 is connected, for example, to the downstream end (or near the downstream end) of the throttle flow path part 33. The fine bubble generator 30 having the multiple protrusions 35 therein as described above is molded, for example, by a method in which the parting surface of a mold is set at the part of the protrusions 35 and the mold is pulled back and forth.

[0033] In the fine-bubble generator 30, the washing water (fluid) and the ozone (gas) are stirred by the plurality of protrusions 35 and the gas inlet 39 disposed downstream thereof, and the ozone is made finer. The fine-bubble generator 30 will be described in more detail below.

[0034] As shown in FIG. 5, when the multiple protrusions 35 have the same size and shape, the tips 35a of the multiple protrusions 35 define a central flow passage Fa having a circular cross section. FIG. 5 shows a virtual circle passing through the tips 35a. The radius of the central flow passage Fa from the central axis A is larger than the height h of each protrusion 35 protruding from the peripheral surface 33a. That is, the height h of the protrusions 35 is sufficiently small to ensure a sufficient cross-sectional area of ​​the central flow passage Fa and not to impede the flow of water. This also contributes to the prevention of cavitation. On the other hand, each protrusion 35 has a shape and size suitable for generating a swirling flow V (see FIG. 6) corresponding to each protrusion 35.

[0035] As shown in FIG. 7, the gap S between two adjacent protrusions 35 in the circumferential direction has a width of about one protrusion 35. The gap S has a width that allows a pair of swirling flows V to be generated on both sides of each protrusion 35 in the circumferential direction. In other words, two swirling flows V are formed between two adjacent protrusions 35 (see FIG. 6 and FIG. 7). The swirling flows V can also be called vortex flows or whirling flows. In the throttled flow passage section 33, a main flow is ensured in the central flow passage section Fa, while multiple swirling flows V are generated in a region close to the circumferential surface 33a. Note that FIG. 7 shows the swirling flows V that flow from the front of the page toward the back.

[0036] According to the fine bubble generator 30 of this embodiment, ozone supplied from the outside is introduced into the flow path F through the gas introduction section 39. The introduced ozone is self-absorbed by the pressure difference generated by the throttle flow path section 33. A plurality of protrusions 35 provided on the throttle flow path section 33 form swirling flows V of water downstream of the protrusions 35. The introduced ozone is caught up in these swirling flows V and is mixed with the water, breaking it into fine particles. This allows a larger number of fine bubbles to be generated in the water.

[0037] Moreover, the height h of each protrusion 35 is kept small, ensuring the cross-sectional area of ​​the central flow passage section Fa. This allows multiple swirling flows V to be generated only near the circumferential surface 33a, without impeding the main water flow. Because the size of the central flow passage section Fa is ensured, the occurrence of cavitation is also prevented. Furthermore, the water supply flow rate (amount of water supplied, or water supply speed) in the washing machine 1 is increased, allowing water to quickly accumulate in the outer tub 6. The water flow ejected from the outlet 30b can also agitate the inside of the outer tub 6.

[0038] Furthermore, by setting the gap S between the adjacent protrusions 35, 35, it is possible to reliably generate a swirling flow V corresponding to each protrusion 35, and thus it is possible to obtain a more suitable stirring effect.

[0039] According to the configuration in which the protrusions 35 include the first triangular pyramid-shaped portions 36, the water flow passes over the side surfaces of the first triangular pyramid-shaped portions 36, making it easier to generate a swirling flow downstream of each protrusion 35.

[0040] According to the washing machine 1 of the present embodiment, water is supplied to the casing 100, and the water containing a large amount of fine bubbles is collected in the outer tub 6 from the outlet 30b. The dissolution rate of ozone is improved, and the efficiency of washing and rinsing is improved.

[0041] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, the gas introduction section 39 may be connected to the second flow path section 32. In that case, the multiple protrusions 35 may be provided at the downstream end of the throttle flow path section 33. A swirling flow generating mechanism centered on the central axis A may be provided on the circumferential surface of the second flow path section 32. In that case, a spiral protrusion that twists (changes the flow in a spiral) in the flow path F may be provided on the circumferential surface of the second flow path section 32, or multiple protrusions or obstacle walls may be provided in the circumferential direction and the central axis A direction. By directing the multiple swirling flows V in a spiral shape, the gas stirring effect is further enhanced.

[0042] For each protrusion 35, the second triangular pyramidal portion 37 of the above embodiment may be omitted and only the first triangular pyramidal portion 36 may be provided. Each protrusion 35 is not limited to a triangular pyramidal shape, and may take various modified forms such as a square pyramidal shape, a conical shape, a hemispherical shape (including an elliptical shape), etc. When the protrusion 35 is a pyramidal or conical shape, the protrusion 35 is provided so that the apex is located on the upstream side.

[0043] The throttle flow passage section 33 is not limited to a tubular section having a circular cross section, but may be a tubular section having a cross section other than a circle (for example, an ellipse or a rectangle). In this case, the "rectangle" may include a rectangle and a square.

[0044] Even when the multiple protrusions 35 have different sizes and / or shapes, the central flow passage Fa is defined by the tip 35a of the tallest protrusion 35. The radius from the central axis A is determined by the central axis A and the tip 35a of the protrusion 35. Even in this case, it is desirable that the radius be greater than the height h of the protrusion 35.

[0045] The gas is not limited to ozone. The gas may be oxygen or air. When the gas is air, the ozone supply device 40 may be omitted (although the cleaning power is lower than that of ozone), and the gas intake port of the gas introduction part 39 (i.e., the gas supply port 30c) may be opened inside the housing 2.

[0046] The present invention may be applied to washing machines other than drum washing machines, for example, vertical washing machines. [Explanation of symbols]

[0047] 1...washing machine, 2...casing, 6...outer tub, 13...water supply pipe, 30...fine bubble generator, 30a...inlet, 30b...outlet, 30c...gas supply port, 31...first flow path section, 32...second flow path section, 33...throttling flow path section, 35...projection, 35a...tip, 36...first triangular pyramid-shaped section (triangular pyramid-shaped section), 37...second triangular pyramid-shaped section, 39...gas introduction section, 40...ozone supply device (gas supply device), 100...casing, A...central axis, F...flow path, Fa...central flow path section, S...gap, V...swirling flow.

Claims

1. A micro-bubble generating device having a flow path formed along a central axis line within a casing, The flow path is A first flow path portion formed on an inlet side of the casing; A second flow path portion formed on an outlet side of the casing; a throttled flow path portion formed between the first flow path portion and the second flow path portion, A plurality of protrusions protruding toward the central axis are provided on a peripheral surface of the throttle flow path portion, A fine-bubble generating device, wherein a gas inlet portion for introducing gas supplied from outside the casing is connected to the downstream side of the plurality of protrusions.

2. 2. The fine-bubble generating device according to claim 1, wherein a radius from the central axis of the central flow passage portion defined by the tips of the plurality of protrusions is greater than a protruding height of each of the plurality of protrusions.

3. 3. The micro-bubble generating device according to claim 1, wherein a circumferential gap between two adjacent protrusions among the plurality of protrusions has a width sufficient to generate a swirling flow corresponding to each protrusion.

4. The micro-bubble generating device according to claim 1 or 2, wherein each of the plurality of protrusions includes a triangular pyramid-shaped portion having an apex located on the upstream side.

5. An outer tank disposed within the housing; The fine bubble generator according to claim 1 or 2, which is attached to the outer tank and has an outlet directed toward the inside of the outer tank; A gas supply device provided in the housing and configured to supply the gas to the gas introduction portion.

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