Microbubble generator, water heater, and dishwasher
The microbubble generator addresses drainage issues by incorporating a venturi channel and drainage channels to enhance liquid drainage and improve bubble quality, ensuring efficient operation and reduced risk of damage from liquid accumulation.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- RINNAI CORP
- Filing Date
- 2022-03-28
- Publication Date
- 2026-07-09
AI Technical Summary
Existing microbubble generators face issues with reduced liquid drainage performance due to the presence of upstream and downstream fitting parts, leading to potential liquid accumulation and malfunctions such as freezing, which can damage the device.
The microbubble generator is designed with a main body case containing a first microbubble generation unit featuring a venturi channel and drainage channels that connect the gap space to the outlet, ensuring liquid drains effectively through multiple points, including a vertically oriented channel near the bottom to prevent accumulation.
This configuration enhances liquid drainage performance by preventing accumulation and ensuring efficient drainage, even when the device is reused, while also improving microbubble generation quality through a secondary microbubble generation section that refines bubbles using swirling flow.
Smart Images
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Abstract
Description
Technical Field
[0001] The technology disclosed in this specification relates to a fine bubble generator, a water heater, and a dishwasher.
Background Art
[0002] Patent Document 1 discloses a fine bubble generator including a main body case having an inflow portion and an outflow portion, and a first fine bubble generation portion housed in the main body case. The first fine bubble generation portion includes a body portion extending between the inflow portion and the outflow portion, a Venturi flow path communicating between the inflow portion and the outflow portion through the inside of the body portion, an upstream fitting portion connected to the upstream end of the body portion and having an outer surface shaped to substantially fit the inner surface of the main body case when viewed from the upstream side inside the main body case, and a downstream fitting portion connected to the downstream end of the body portion and having an outer surface shaped to substantially fit the inner surface of the main body case when viewed from the downstream side inside the main body case. The Venturi flow path includes a reduced-diameter flow path whose flow path diameter decreases from the upstream side to the downstream side, and an enlarged-diameter flow path provided on the downstream side of the reduced-diameter flow path and whose flow path diameter increases from the upstream side to the downstream side. A gap space is provided inside the main body case between the inner surface of the main body case and the outer surface of the body portion, and between the upstream fitting portion and the downstream fitting portion.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In microbubble generators such as those described in Patent Document 1, upstream and downstream fitting parts are provided to stabilize the position of the first microbubble generation unit within the main body case. However, the provision of upstream and downstream fitting parts can reduce the liquid drainage performance of liquids that have entered the gap space. In this case, after draining the liquid from the microbubble generator, liquid may accumulate in the gap space, potentially causing malfunctions (for example, damage to the case due to freezing of the accumulated liquid). This specification provides a technology that can improve the liquid drainage performance of the gap space. [Means for solving the problem]
[0005] The microbubble generating apparatus disclosed herein comprises a main body case having an inlet and an outlet, and a first microbubble generating unit housed in the main body case. The first microbubble generating unit comprises a body portion extending between the inlet and the outlet, a venturi channel passing through the interior of the body portion and communicating the inlet and the outlet, an upstream fitting portion connected to the upstream end of the body portion and having an outer surface shaped to substantially fit onto the inner surface of the main body case when the interior of the main body case is viewed from the upstream side, and a downstream fitting portion connected to the downstream end of the body portion and having an outer surface shaped to substantially fit onto the inner surface of the main body case when the interior of the main body case is viewed from the downstream side. The venturi channel comprises a diameter-reducing channel whose channel diameter decreases as it moves from the upstream side to the downstream side, and a diameter-expanding channel provided downstream of the diameter-reducing channel whose channel diameter increases as it moves from the upstream side to the downstream side. Inside the main body case, there is a gap space formed between the inner surface of the main body case and the outer surface of the body portion, between the upstream fitting portion and the downstream fitting portion, and one or more drainage channels are provided that connect the gap space to the outlet portion.
[0006] According to the above configuration, when the microbubble generator performs liquid drainage so that the liquid inside the main case drains from the inlet to the outlet, the liquid in the gap space drains to the outlet through one or more drainage channels. Therefore, the liquid drainage performance of the gap space can be improved.
[0007] In one or more embodiments, the drainage channels are plurality, comprising a first drainage channel and a second drainage channel.
[0008] With the above configuration, when the microbubble generator performs liquid draining so that the liquid inside the main case drains from the inlet to the outlet, the liquid in the gap space drains out to the outlet from multiple points. Therefore, the liquid draining performance of the gap space can be further improved.
[0009] In one or more embodiments, at least one of the one or more drainage channels is connected to the gap space near the bottom of the gap space, with its vertically downward orientation being downward.
[0010] Normally, when draining a microbubble generator, the liquid in the gap space drains downward due to gravity. Therefore, liquid accumulation is likely to occur, especially near the bottom of the gap space, after draining the microbubble generator. With the above configuration, at least one drain channel is oriented vertically downwards and connects to the gap space near the bottom. This effectively prevents liquid accumulation in the gap space after draining the microbubble generator.
[0011] In one or more embodiments, the microbubble generator further comprises a second microbubble generator housed in the main body case and provided between the first microbubble generation unit and the outflow unit. The second microbubble generator comprises a shaft portion extending in a direction from upstream to downstream, an outer periphery surrounding the radially outer side of the shaft portion, a plurality of blade portions provided between the shaft portion and the outer periphery and generating a swirling flow that flows in a predetermined swirling direction relative to the shaft portion, and a swirling flow path passing through the gaps between the shaft portion, the outer periphery, and the plurality of blade portions.
[0012] According to the above configuration, a second microbubble generation section is further provided downstream of the first microbubble generation section. Therefore, the liquid flowing into the inlet not only passes through the venturi channel of the first microbubble generation section, but also through the swirling channel of the second microbubble generation section. In this case, the microbubbles generated in the first microbubble generation section become even finer due to the shear force caused by the swirling flow generated in the second microbubble generation section, and the quantity of microbubbles increases. According to the above configuration, a large amount of microbubbles can be generated.
[0013] In one or more embodiments, the main body case has a substantially cylindrical inner surface extending from the upstream side to the downstream side. The first microbubble generating section is formed of resin. The body has a diameter-reducing outer surface in the portion where the diameter-reducing channel is provided, which decreases in diameter as it moves from the upstream side to the downstream side. The body has an expanding outer surface in the portion where the diameter-expanding channel is provided, which expands in diameter as it moves from the upstream side to the downstream side.
[0014] When resin is used in the first microbubble generation section, it is common to form the first microbubble generation section by injection molding. In this case, if the wall thickness of the first microbubble generation section (especially the body section) is large, quality defects in the first microbubble generation section are likely to occur. In contrast, with the above configuration, the wall thickness of the body section can be reduced. Therefore, when the first microbubble generation section is formed by injection molding, the quality of the first microbubble generation section can be improved. Furthermore, with the above configuration, the volume of the gap space is increased, so the effect of improving the liquid drainage performance of the gap space according to this invention is more pronounced.
[0015] In one or more embodiments, the first microbubble generating section is provided with one or more notches formed by cutting out a portion of the downstream fitting section from the downstream side toward the upstream side. The one or more notches function as one or more liquid drainage channels.
[0016] According to the above configuration, by partially processing the first microbubble generation unit, one or more liquid drainage channels can be formed. Therefore, one or more liquid drainage channels can be easily formed.
[0017] In one or more embodiments, the first microbubble generation unit is provided with one or more recesses having a shape that is recessed inward from the outer surface of the body portion. The one or more recesses are connected to the one or more notch portions.
[0018] According to the above configuration, the liquid in the gap space is easily guided to the one or more notch portions by the one or more recesses. That is, the liquid in the gap space is easily guided to the one or more liquid drainage channels. Therefore, the liquid drainage performance of the gap space can be further improved.
[0019] The water heater disclosed in this specification includes the above-described microbubble generator.
[0020] According to the above configuration, in the microbubble generator included in the water heater, the liquid drainage performance of the gap space can be improved.
[0021] The dishwashing machine disclosed in this specification includes the above-described microbubble generator.
[0022] According to the above configuration, in the microbubble generator included in the dishwashing machine, the liquid drainage performance of the gap space can be improved.
Brief Description of the Drawings
[0023] [Figure 1] It is a diagram schematically showing the configuration of the water heater 100 according to Example 1. [Figure 2] It is an overall perspective view of the microbubble generator 2 according to Examples 1 and 2. [Figure 3] It is a cross-sectional view of the microbubble generator 2 according to Examples 1 and 2. [Figure 4]It is an overall perspective view of the first fine bubble generation unit 3 included in the fine bubble generator 2 according to Embodiments 1 and 2. [Figure 5] It is a cross-sectional view taken along line V-V of FIG. 3. [Figure 6] It is a cross-sectional view taken along line VI-VI of FIG. 3. [Figure 7] It is a view of the second fine bubble generation unit 5 included in the fine bubble generator 2 according to Embodiments 1 and 2 as seen from the upstream side. [Figure 8] It is a view of the second fine bubble generation unit 5 included in the fine bubble generator 2 according to Embodiments 1 and 2 as seen from a direction perpendicular to the central axis A. [Figure 9] It is a view showing an installation example of the fine bubble generator 2 according to Embodiments 1 and 2. [Figure 10] It is a view schematically showing the configuration of the dishwasher 510 according to Embodiment 2.
Modes for Carrying Out the Invention
[0024] (Embodiment 1: Water heater 100 equipped with fine bubble generator 2) As shown in FIG. 1, the water heater 100 includes a fine bubble generator 2, a water supply pipe 104, a first drain plug 106, a water volume sensor 108, a water volume servo 110, a water heater controller 112, a heat exchanger 114, a gas burner 116, a combustion fan 118, a hot water supply pipe 122, a hot water supply thermistor 124, and a second drain plug 126.
[0025] The upstream end of the water supply pipe 104 is connected to a water supply source such as a water supply. In the middle of the water supply pipe 104, a first drain plug 106, a water volume sensor 108, and a water volume servo 110 are provided in order from the upstream side. The water volume sensor 108 detects the flow rate of the water flowing through the water supply pipe 104. The water volume servo 110 allows or prohibits water flow by switching between an open state and an open state. The water flow rate in the open water volume servo 110 changes according to the opening degree of the water volume servo 110. In this embodiment, air (such as oxygen, carbon dioxide, nitrogen, etc.) is dissolved in the water (for example, tap water) supplied from the water supply source.
[0026] The upstream end of the heat exchanger 114 is connected to the downstream end of the water supply pipe 104. The gas burner 116 heats the water flowing through the heat exchanger 114 by burning the supplied combustion gas. The downstream end of the heat exchanger 114 is connected to the upstream end of the hot water supply pipe 122. Along the hot water supply pipe 122, in order from the upstream side, are a hot water thermistor 124, a microbubble generator 2, and a second drain valve 126. The hot water thermistor 124 detects the temperature of the water flowing through the hot water supply pipe 122. The downstream end of the hot water supply pipe 122 is connected to a hot water outlet such as a faucet or bathtub. Hereinafter, the hot water supply pipe 122 connected to the upstream end of the microbubble generator 2 may be referred to as the "first hot water supply pipe 122a," and the hot water supply pipe 122 connected to the downstream end of the microbubble generator 2 may be referred to as the "second hot water supply pipe 122b."
[0027] The water heater controller 112 is equipped with a CPU, ROM, RAM, etc. The water heater controller 112 receives information on the water flow rate detected by the water flow sensor 108 and the water temperature detected by the hot water thermistor 124. The water heater controller 112 can adjust the amount of water flowing from the water supply pipe 104 to the heat exchanger 114 by adjusting the opening of the water flow servo 110. The water heater controller 112 can also adjust the heat output of the gas burner 116 by adjusting the amount of combustion gas supplied to the gas burner 116. The water heater controller 112 can adjust the temperature of the water flowing through the hot water pipe 122 to a desired temperature by controlling the operation of the water flow servo 110 and the gas burner 116 based on the information detected by the water flow sensor 108 and the hot water thermistor 124.
[0028] (Configuration of microbubble generator 2) As shown in Figure 2, the microbubble generator 2 comprises a main body case 10, an inlet 12, and an outlet 14. The main body case 10 has a substantially cylindrical shape centered on a central axis A. The inlet 12 and the outlet 14 are each fixed to the main body case 10 with screws. The downstream end of the first hot water supply pipe 122a (see Figure 1) is connected to the inlet 12. The upstream end of the second hot water supply pipe 122b (see Figure 1) is connected to the outlet 14. Therefore, water flowing in from the first hot water supply pipe 122a flows into the inlet 12, passes through the main body case 10, and flows out from the outlet 14 to the second hot water supply pipe 122b.
[0029] As shown in Figure 3, the main body case 10 houses a first microbubble generation unit 3 and a plurality of second microbubble generation units 5. The first microbubble generation unit 3 and the plurality of second microbubble generation units 5 are arranged along the central axis A. The plurality of second microbubble generation units 5 are arranged side by side downstream of the first microbubble generation unit 3. In this embodiment, four plurality of second microbubble generation units 5 are provided. All of the plurality of second microbubble generation units 5 have the same shape.
[0030] (Configuration of the first microbubble generation unit 3) As shown in Figure 4, the first microbubble generation unit 3 has a substantially rotating body shape centered on the central axis A. The first microbubble generation unit 3 comprises a body portion 30, an inner venturi channel 32, a plurality of outer venturi channels 34, an upstream fitting portion 36, and a downstream fitting portion 38. In this embodiment, the first microbubble generation unit 3 is integrally formed by injection molding using a resin (for example, polypropylene or polyphenylene sulfide). Therefore, the body portion 30, the upstream fitting portion 36, and the downstream fitting portion 38 are integrally formed without seams. As shown in Figure 3, the body portion 30 extends between the inlet portion 12 and the outlet portion 14, and has a reduced-diameter outer surface 302 that decreases in diameter from the upstream side to the downstream side along the central axis A, and an enlarged-diameter outer surface 304 connected to the downstream end of the reduced-diameter outer surface 302 that increases in diameter from the upstream side to the downstream side along the central axis A.
[0031] Near the downstream end of the body portion 30, a first recess 306 and a second recess 308 are provided, which have a shape that is recessed from the enlarged outer surface 304 toward the radially inward direction of the central axis A. As shown in Figure 5, the first recess 306 and the second recess 308 are provided to a depth that does not interfere with the multiple outer venturi flow channels 34. The first recess 306 and the second recess 308 are arranged at a distance of 180° from each other in the circumferential direction of the central axis A. The first recess 306 and the second recess 308 are provided so as to extend from the downstream end of the body portion 30 toward the upstream side.
[0032] As shown in Figure 3, the first recess 306 includes a first inclined portion 306a that slopes toward the central axis A as it moves from the upstream side to the downstream side, and a first bottom portion 306b connected to the first inclined portion 306a and extending along the central axis A. The first inclined portion 306a smoothly connects the enlarged outer surface 304 and the first bottom portion 306b. The second recess 308 includes a second inclined portion 308a that slopes toward the central axis A as it moves from the upstream side to the downstream side, and a second bottom portion 308b connected to the second inclined portion 308a and extending along the central axis A. The second inclined portion 308a smoothly connects the enlarged outer surface 304 and the second bottom portion 308b.
[0033] The inner venturi channel 32 and the multiple outer venturi channels 34 communicate between the inlet 12 and the outlet 14 by passing through the inside of the body 30. The inner venturi channel 32 extends along the central axis A. As shown in Figure 4, the multiple outer venturi channels 34 are arranged to surround the inner venturi channel 32. In this embodiment, seven of the multiple outer venturi channels 34 are provided. The multiple outer venturi channels 34 are arranged at predetermined angular intervals (approximately 51° intervals in this embodiment) in the circumferential direction of the central axis A.
[0034] As shown in Figure 3, the inner venturi channel 32 includes an inner diameter-reducing channel 322, whose channel diameter decreases as it moves from the upstream side to the downstream side along the central axis A, and an inner diameter-expanding channel 324, which is located downstream of the inner diameter-reducing channel 322 and whose channel diameter expands as it moves from the upstream side to the downstream side along the central axis A.
[0035] As shown in Figure 5, the inner venturi channel 32 has a plurality of slits 4 formed in the inner surface of the inner venturi channel 32 that are recessed radially outward from the central axis A. In this embodiment, two plurality of slits 4 are provided. The plurality of slits 4 are arranged at predetermined angular intervals (180° intervals in this embodiment) in the circumferential direction of the central axis A. In other words, the plurality of slits 4 are arranged on the inner surface of the inner venturi channel 32 so as to face each other. Furthermore, each of the plurality of slits 4 is provided continuously from a first end 42 that coincides with the downstream end of the inner diameter-expanding channel 324 to a second end 44 that is located upstream of the downstream end of the inner diameter-expanding channel 324. Each of the plurality of slits 4 has a substantially constant width in the direction perpendicular to the recession direction. The width of the plurality of slits 4 is, for example, in the range of 0.5 mm to 3.0 mm, and in this embodiment it is 1.5 mm. Note that the plurality of slits 4 are provided only in the inner venturi channel 32 and not in the plurality of outer venturi channels 34.
[0036] As shown in Figure 3, the second end portion 44 is located downstream of the downstream end of the inner diameter-reducing channel 322. In this embodiment, the second end portion 44 coincides with the upstream end of the inner diameter-expanding channel 324. Each of the multiple slits 4 has a substantially constant depth in the radial direction of the central axis A. The depth of the multiple slits 4 is, for example, in the range of 0.5 mm to 3.0 mm, and in this embodiment it is 1.8 mm. Each of the multiple slits 4 is provided to extend substantially linearly from the first end portion 42 to the second end portion 44. Also, as shown in Figure 4, the downstream end of the inner diameter-expanding channel 324 has a bell-mouth shape. Therefore, near the first end portion 42, the peripheral edges of the multiple slits 4 have a curved shape that follows the bell-mouth shape of the inner diameter-expanding channel 324.
[0037] As shown in Figure 3, the multiple outer venturi channels 34 include an outer diameter-reducing channel 342 whose diameter decreases as it moves from upstream to downstream, and an outer diameter-expanding channel 344 located downstream of the outer diameter-reducing channel 342, whose diameter increases as it moves from upstream to downstream. The downstream end of the outer diameter-expanding channel 344 has a bell mouth shape. All of the multiple outer venturi channels 34 have the same shape.
[0038] As shown in Figure 4, the upstream fitting portion 36 has a flange shape that protrudes from the upstream end of the body portion 30 so as to extend radially outward along the central axis A. The upstream fitting portion 36 has an outer surface 36a that extends in the circumferential direction along the central axis A. As shown in Figure 6, when the inside of the main body case 10 is viewed from the upstream side, the outer surface 36a of the upstream fitting portion 36 substantially fits onto the inner surface 10a of the main body case 10 over its entire length. Therefore, the space between the outer surface 36a of the upstream fitting portion 36 and the inner surface 10a of the main body case 10 is mechanically sealed.
[0039] As shown in Figure 4, the downstream fitting portion 38 protrudes from the downstream end of the body portion 30 so as to spread radially outward along the central axis A, and extends downstream of the downstream end of the body portion 30 along the central axis A. At the downstream end of the downstream fitting portion 38, the downstream fitting portion 38 is provided with an engaging projection 382 that partially protrudes downstream. The first microbubble generating portion 3 is also provided with a first notch 6 and a second notch 8, which are formed by cutting out a part of the downstream fitting portion 38 from the downstream side toward the upstream side. The first notch 6 is smoothly connected to the first recess 306 of the body portion 30. The second notch 8 is smoothly connected to the second recess 308 of the body portion 30.
[0040] As shown in Figure 5, when the inside of the main case 10 is viewed from the downstream side, the outer surface 38a of the downstream fitting portion 38 substantially fits onto the inner surface 10a of the main case 10 over almost the entire length of the inner surface 10a of the main case 10, except for the portions where the first notch 6 and the second notch 8 are formed. Furthermore, the engaging projection 382 engages from the upstream side with the positioning member 10b that protrudes inward from the inner surface 10a of the main case 10. As a result, the first microbubble generating portion 3 is housed in the main case 10 in a state where it is positioned relative to the main case 10 in the axial direction and circumferential direction of the central axis A.
[0041] As shown in Figure 3, a gap space S is formed between the inner surface 10a of the main body case 10 and the reduced-diameter outer surface 302 and the enlarged-diameter outer surface 304 of the body portion 30, and between the upstream fitting portion 36 and the downstream fitting portion 38. Since the space between the outer surface 36a of the upstream fitting portion 36 and the inner surface 10a of the main body case 10 is mechanically sealed, the inflow and outflow of water is suppressed on the upstream side of the gap space S. On the other hand, on the downstream side of the gap space S, the inflow and outflow of water is permitted by the first drainage channel D1, which consists of the first notch 6 and the first recess 306, and the second drainage channel D2, which consists of the second notch 8 and the second recess 308. For this reason, the gap space S is in communication with the outflow portion 14 through the first drainage channel D1 and the second drainage channel D2.
[0042] (Configuration of the second microbubble generation section 5) As shown in Figure 7, the second microbubble generation unit 5 comprises a shaft portion 52, an outer peripheral portion 54 surrounding the shaft portion 52, and a plurality of blade portions 56 provided between the shaft portion 52 and the outer peripheral portion 54, which generate a swirling flow that flows clockwise relative to the shaft portion 52. In this specification, "clockwise direction" and "counterclockwise direction" refer to the direction when viewing the microbubble generator 2 from the upstream side along the central axis A. The second microbubble generation unit 5 is integrally formed by injection molding using a resin (for example, polypropylene or polyphenylene sulfide). Therefore, the shaft portion 52, the outer peripheral portion 54, and the plurality of blade portions 56 are integrally formed without seams.
[0043] The shaft portion 52 has a cylindrical shape. The outer peripheral portion 54 has a cylindrical shape. The outer peripheral portion 54 has an outer surface that substantially fits onto the inner surface 10a of the main body case 10. The shaft portion 52 and the outer peripheral portion 54 are provided along the central axis A. Multiple blade portions 56 connect the outer wall of the shaft portion 52 and the inner wall of the outer peripheral portion 54. The multiple blade portions 56 are inclined downstream as they are moved clockwise. In this embodiment, seven multiple blade portions 56 are provided. The multiple blade portions 56 are arranged at predetermined angular intervals (approximately 51° intervals in this embodiment) in the circumferential direction of the central axis A. The second microbubble generation section 5 is also provided with seven swirling channels 64 (thick lines in Figure 7). Each of the seven swirling channels 64 is provided in the gap between the shaft portion 52, the outer peripheral portion 54, and the multiple blade portions 56.
[0044] As shown in Figure 8, the outer periphery 54 has a fitting projection 66 that partially protrudes upstream at its upstream end. The outer periphery 54 has a fitting recess 68 that partially recesses upstream at its downstream end. The fitting projection 66 and the fitting recess 68 have a shape that allows them to fit together.
[0045] Focusing on the two adjacent second microbubble generating units 5, the fitting projection 66 of the downstream second microbubble generating unit 5 fits into the fitting recess 68 of the upstream second microbubble generating unit 5. This positions the multiple second microbubble generating units 5 relative to each other. Furthermore, the fitting projection 66 of the uppermost second microbubble generating unit 5 engages with the positioning member 10b (see Figure 5) of the main body case 10 from the downstream side. Thus, each of the multiple second microbubble generating units 5 is housed in the main body case 10 in a state where it is positioned in the circumferential direction of the central axis A relative to the main body case 10.
[0046] (Principle of microbubble formation) As shown in Figure 1, since air is dissolved in the water supplied from the water source, air is also dissolved in the water flowing through the first hot water pipe 122a. Therefore, water containing dissolved air flows into the microbubble generator 2 from the first hot water pipe 122a. Hereafter, water containing dissolved air may be referred to as "air-dissolved water".
[0047] As shown in Figure 3, the air-dissolved water that flows into the main case 10 from the inlet 12 flows into the narrowed diameter channels 322 and 342 of the Venturi channels 32 and 34. The air-dissolved water that flows into the narrowed diameter channels 322 and 342 increases in flow velocity as it passes through the narrowed diameter channels 322 and 342, and as a result the pressure is reduced. Bubbles are generated as the air-dissolved water is reduced in pressure. The air-dissolved water that has passed through the narrowed diameter channels 322 and 342 flows into the widened diameter channels 324 and 344. The air-dissolved water that flows into the widened diameter channels 324 and 344 decreases in flow velocity as it passes through the widened diameter channels 324 and 344, and as a result the pressure is increased. When the air-dissolved water, which has been generated by the pressure reduction, is pressurized, the bubbles contained in the air-dissolved water split and become fine bubbles. In this specification, the inner Venturi channel 32 and the multiple outer Venturi channels 34 are sometimes collectively referred to as "Venturi channels 32 and 34". Similarly, the inner diameter-reducing channel 322 and the outer diameter-reducing channel 342 are sometimes collectively referred to as "diameter-reducing channels 322 and 342." Similarly, the inner diameter-expanding channel 324 and the outer diameter-expanding channel 344 are sometimes collectively referred to as "diameter-expanding channels 324 and 344."
[0048] The air-dissolved water flowing out of the first microbubble generation unit 3, passing through the enlarged diameter channels 324 and 344, flows toward the second microbubble generation unit 5 on the upstream side. At this time, the air-dissolved water flowing out of the inner venturi channel 32 collides with the upstream end of the shaft portion 52 of the second microbubble generation unit 5 on the upstream side, is pushed radially outward from the central axis A, and flows into the swirling channel 64. On the other hand, the air-dissolved water flowing out of the multiple outer venturi channels 34 flows into the swirling channel 64 without colliding with the shaft portion 52. Thereafter, the air-dissolved water passes through each of the swirling channels 64 of the multiple second microbubble generation units 5 from upstream to downstream. The air-dissolved water flowing through the swirling channel 64 flows along the blade portion 56, creating a swirling flow that flows in a clockwise direction. The microbubbles in the air-dissolved water become finer due to the shear force caused by the swirling flow, and the amount of microbubbles increases. Then, the air-dissolved water that flows out from the swirling channel 64 of the second microbubble generation unit 5 at the downstream end is guided to the outlet unit 14. In this way, the water heater 100 (see Figure 1) is supplied with hot water containing many microbubbles at the hot water outlet.
[0049] (Water drainage mechanism of microbubble generator 2) As shown in Figure 1, the microbubble generator 2 can be drained by opening the first drain plug 106 and the second drain plug 126. When the first drain plug 106 and the second drain plug 126 are open, the water between the first drain plug 106 and the second drain plug 126 flows due to gravity and flows out from either the first drain plug 106 or the second drain plug 126. At this time, in the microbubble generator 2, the water flows from the inlet 12 to the outlet 14 (see Figure 3).
[0050] As shown in Figure 9, the microbubble generator 2 of this embodiment is installed such that the direction toward the upstream side along the central axis A is vertically upward, and the direction toward the downstream side along the central axis A is vertically downward. Therefore, when the water is drained from the microbubble generator 2, the water inside the main case 10 (water in the gap space S) drains downward due to gravity. In other words, as the water drains out, the water level inside the main case 10 decreases downstream along the central axis A. In this specification, the vertically upward direction is sometimes referred to as "upward," and the vertically downward direction is sometimes referred to as "downward."
[0051] In the state shown in Figure 9, the first drain channel D1 is connected to the vicinity of the bottom of the gap space S. Similarly, the second drain channel D2 is also connected to the vicinity of the bottom of the gap space S. Therefore, when draining water from the microbubble generator 2, almost all of the water in the gap space S flows into either the first drain channel D1 or the second drain channel D2. In this specification, "the vicinity of the bottom of the gap space S" means the part within L / 4 (mm) above the bottom of the gap space S, where L (mm) is the vertical length from the bottom to the top of the gap space S. In this embodiment, since the vertical length from the bottom to the top of the gap space S is 40 mm, "the vicinity of the bottom of the gap space S" in this embodiment means the part within 10 mm above the bottom of the gap space S.
[0052] Furthermore, when the microbubble generator 2 is drained, a water film may form in the enlarged channels 324 and 344 of the venturi channels 32 and 34 (especially near the downstream ends of the enlarged channels 324 and 344). If the water film formed in the enlarged channels 324 and 344 freezes without being cleared, then even if water is subsequently passed through the microbubble generator 2, the frozen water film may obstruct the flow, potentially preventing immediate water flow.
[0053] In the microbubble generator 2 of this embodiment, when a water film forms in the inner diameter-expanding channel 324 of the inner venturi channel 32, the water film is drawn into the multiple slits 4 and moves upstream along the inner diameter-expanding channel 324. As shown in Figure 3, the inner diameter-expanding channel 324 decreases in diameter as it moves upstream, so the surface area of the water film decreases as it moves upstream. At this time, the water film condenses as its surface area decreases, and is dissolved by forming water droplets. In this way, the water film formed in the inner diameter-expanding channel 324 can be dissolved in the inner venturi channel 32. Therefore, even if the water film in the outer diameter-expanding channel 344 freezes after draining, the water film in the inner diameter-expanding channel 324 has been dissolved, so at least in the inner diameter-expanding channel 324, water flow will not be obstructed by the frozen water film. For this reason, water can be immediately supplied even when the microbubble generator 2 is reused after draining, improving the convenience of the microbubble generator 2.
[0054] (Example 2: Dishwasher 510 equipped with microbubble generator 2) Figure 10 is a longitudinal cross-sectional view of the dishwasher 510. The dishwasher 510 is a drawer-type dishwasher. The dishwasher 510 comprises a microbubble generator 2, a main body 512, a washing tank 514, a door 515, and a washing machine controller 560. The microbubble generator 2 in this embodiment is the same as the microbubble generator 2 in Embodiment 1. Therefore, the description of the configuration of the microbubble generator 2 is omitted in this embodiment.
[0055] The door 515 is provided with an operation panel 516 and an exhaust path 518. The operation panel 516 is equipped with various buttons such as a start button and lights. The exhaust path 518 extends from the inside to the outside of the washing tank 514.
[0056] The cleaning tank 514 is housed in the space formed by the main body 512 and the door 515. The cleaning tank 514 is slidably supported by the main body 512. The cleaning tank 514 is connected to the door 515. The cleaning tank 514 is formed in the shape of a box with an open top. A lid 556 is positioned above the cleaning tank 514. The lid 556 is connected to the cleaning tank 514 by a lifting mechanism (not shown).
[0057] The washing tank 514 houses a washing nozzle 520, a dish basket 561 for holding various dishes 519, a food residue filter 517, a heater 530, a thermistor 555, and the like. The washing nozzle 520 consists of a tower nozzle section 523 comprising an upper nozzle 521 and a lower nozzle 522, and a horizontal nozzle section 524. The washing nozzle 520 has multiple spray ports 521a, 522a, and 524a. An electric heater 530 for heating the washing water and the air inside the washing tank 514 is mounted near the bottom surface 539 of the washing tank 514. A thermistor 555 is mounted on the bottom surface 539 of the washing tank 514.
[0058] A water level detection unit 545 for detecting the water level inside the cleaning tank 514 is provided at the lower front outer part of the cleaning tank 514. The water level when cleaning water is supplied to the cleaning tank 514 normally (hereinafter referred to as "cleaning water level") is indicated by the dashed line of reference numeral 554. A pump 527 is provided below the bottom surface 539 of the cleaning tank 514. The pump 527 rotates an impeller 528 with a built-in electric motor. A cleaning nozzle 520 is rotatably mounted on the bottom surface 539 of the cleaning tank 514. The cleaning nozzle 520 and the first discharge port 511 of the pump 527 are in communication.
[0059] A suction recess 531 is formed at the bottom of the washing tank 514. The upper opening of the suction recess 531 is covered by a food residue filter 517. The water level detection unit 545 and the suction recess 531 are connected by a water level path 550. The pump 527 and the suction recess 531 are connected by a first suction passage 532. One end of a second suction passage 574 is connected to the first suction passage 532. The other end of the second suction passage 574 is connected to an opening 572 in the rear wall 551 of the washing tank 514. A flow path switching valve 576 is installed at the connection between the first suction passage 532 and the second suction passage 574.
[0060] A drying fan 552 is mounted on the outside of the rear wall 551 of the washing tank 514. The drying fan 552 rotates a fan 553 with its built-in motor. The drying fan 552 and the inside of the washing tank 514 are connected by a drying path 563. The drying fan 552 is positioned higher than the washing water level 554.
[0061] A drain hose 534 is connected to the rear wall 533 of the main body 512. The drain hose 534 and the second discharge port 535 of the pump 527 are connected by a drain passage 536. The middle of the drain passage 536 and the inside of the cleaning tank 514 are connected by an air vent passage 537. A drain check valve 538 is installed near the point where the drain passage 536 is connected to the drain hose 534.
[0062] A water supply hose 540 is connected to a stepped section horizontally formed in the middle of the rear wall 533 of the main body 512. Water supplied directly from a water source (not shown), such as a public water supply, or heated hot water may be supplied to the water supply hose 540. A water supply valve 541 is installed on the inside of the rear wall 533. The inlet 544 of the water supply valve 541 and the water supply hose 540 are connected by a first water supply channel 542. The outlet 564 of the water supply valve 541 and the inside of the washing tank 514 are connected by a second water supply channel 543. A microbubble generator 2 is installed in the middle of the second water supply channel 543.
[0063] The dishwasher controller 560 is equipped with a CPU, ROM, RAM, etc., and controls the operation of the dishwasher 510. By controlling the operation of the dishwasher 510, the dishwasher controller 560 performs a washing operation to wash the dishes 519 in the washing tank 514.
[0064] (Washing operation) When the washing machine controller 560 receives a command from the user to start the dishwashing operation on the control panel 516, it sequentially executes the washing process, rinsing process, and drying process.
[0065] During the cleaning process, the cleaning machine controller 560 opens the water supply valve 541 to supply cleaning water from the water supply hose 540 to the cleaning tank 514. When the cleaning machine controller 560 determines that the required amount of cleaning water has been supplied to the cleaning tank 514 during the cleaning process, it closes the water supply valve 541. Next, the cleaning machine controller 560 drives the pump 527 to rotate the impeller 528 in the forward direction and turns on the heater 530. The cleaning water is drawn into the pump 527 from the suction recess 531. The cleaning water drawn into the pump 527 is sent to the cleaning nozzle 520 and forcefully ejected from the nozzles 521a, 522a, and 524a. The cleaning machine controller 560 terminates the cleaning process after a first predetermined time (for example, 5 minutes) has elapsed since the start of the cleaning process. Furthermore, the washing machine controller 560 drives the pump 527 and reverses the rotation of the impeller 528 to drain the washing water from the washing tank 514. As described above, a microbubble generator 2 is installed in the middle of the second water supply channel 543. The water supplied from the water supply hose 540 contains dissolved air (oxygen, carbon dioxide, nitrogen, etc.). Therefore, the water supplied to the washing tank 514 after passing through the microbubble generator 2 contains many microbubbles. Dirt components attached to the dishes 519 are adsorbed onto the surface of the microbubbles contained in the washing water. By containing many microbubbles in the washing water, more dirt components can be adsorbed.
[0066] During the rinsing process, the washing machine controller 560 opens the water supply valve 541 to supply washing water from the water supply hose 540 to the washing tank 514. Once the required amount of washing water has been supplied to the washing tank 514, the washing machine controller 560 closes the water supply valve 541. The washing machine controller 560 drives the pump 527 to rotate the impeller 528 in the forward direction. This causes the washing water in the washing tank 514 to be sprayed from the washing nozzle 520 onto the dishes 519 contained in the dish basket 561, rinsing the dishes 519. The washing machine controller 560 terminates the rinsing process after a second predetermined time (for example, 5 minutes) has elapsed since the start of the rinsing process. The washing machine controller 560 also drives the pump 527 to rotate the impeller 528 in the reverse direction, thereby draining the washing water from the washing tank 514.
[0067] In the drying process, the washing machine controller 560 heats the air in the washing tank 514 with the heater 530 to dry the dishes 519. When the elapsed time since the start of drying the dishes 519 reaches a third predetermined time, the washing machine controller 560 terminates the heating by the heater 530 and ends the drying process.
[0068] (modified version) In the above embodiment, a configuration was described in which the microbubble generating device 2 includes a second microbubble generating unit 5 in addition to the first microbubble generating unit 3. In another embodiment, the microbubble generating device 2 may include only the first microbubble generating unit 3, or it may not include the second microbubble generating unit 5.
[0069] In the above embodiment, a configuration was described in which the inner surface 10a of the main case 10 has a substantially cylindrical shape. In another embodiment, the inner surface 10a of the main case 10 does not have to have a substantially cylindrical shape. For example, the inner surface 10a of the main case 10 may have a square tubular shape. In this case, the upstream fitting portion 36, the downstream fitting portion 38, and the outer peripheral portion 54 may have a square tubular shape similar to the inner surface 10a, and may be substantially fitted to the inner surface 10a.
[0070] In the above embodiment, a configuration was described in which the body portion 30 has a reduced-diameter outer surface 302 and an enlarged-diameter outer surface 304. In another embodiment, the body portion 30 may have a cylindrical outer surface centered on the central axis A. Furthermore, the outer surface of the body portion 30 may smoothly connect the outer surface 36a of the upstream fitting portion 36 and the outer surface 38a of the downstream fitting portion 38, or it may have a shape that substantially fits onto the inner surface 10a of the main body case 10 over substantially the entire inner surface 10a. In this case, the resistance to fracture of the first microbubble generation portion 3 can be improved by increasing the wall thickness of the body portion 30.
[0071] In the above embodiment, a configuration in which the first microbubble generating section 3 is formed of resin was described. In another embodiment, the first microbubble generating section 3 may be formed of metal (for example, aluminum or stainless steel). In this case, the first microbubble generating section 3 may consist of a plurality of parts, and each part may be fixed together by welding or the like.
[0072] In the above embodiment, a configuration was described in which a plurality of slits 4 are provided substantially linearly from the first end 42 to the second end 44. In another embodiment, the plurality of slits 4 may be provided spirally around the central axis A from the first end 42 to the second end 44.
[0073] In the above embodiment, a configuration was described in which the second ends 44 of the multiple slits 4 are located downstream of the downstream end of the inner diameter-reducing channel 322 (a configuration in which the second ends 44 coincide with the upstream end of the inner diameter-expanding channel 324). In another embodiment, the second ends 44 may extend upstream of the downstream end of the inner diameter-reducing channel 322. For example, the second ends 44 may coincide with the upstream end of the inner diameter-reducing channel 322. In this case, although the amount of microbubble generation in the inner venturi channel 32 will decrease, the water film can be eliminated more reliably. In yet another embodiment, the second ends 44 may be located downstream of the upstream end of the inner diameter-expanding channel 324.
[0074] In the above embodiment, a configuration was described in which multiple slits 4 are provided in the inner venturi flow path 32 but not in the multiple outer venturi flow paths 34. In another embodiment, the multiple slits 4 may not be provided in the inner venturi flow path 32 but may be provided in the multiple outer venturi flow paths 34. In this case, the multiple slits 4 may be provided in at least one of the multiple outer venturi flow paths 34. In yet another embodiment, the multiple slits 4 may be provided in both the inner venturi flow path 32 and the multiple outer venturi flow paths 34.
[0075] In the above embodiment, a configuration was described in which both the first notch 6 and the first recess 306 (or the second notch 8 and the second recess 308) function as the first drainage channel D1 (or the second drainage channel D2). In another embodiment, one of the first notch 6 and the first recess 306 (or the second notch 8 and the second recess 308) may not be provided. In this case, only the other of the first notch 6 and the first recess 306 (or the second notch 8 and the second recess 308) may function as the first drainage channel D1 (or the second drainage channel D2). In yet another embodiment, instead of providing the first notch 6 and the first recess 306 (or the second notch 8 and the second recess 308), a recess having a shape that is recessed inward from the outer surface 38a of the downstream fitting portion 38 may be provided. In this case, the recess provided in the downstream fitting portion 38 may function as the first drainage channel D1 (or the second drainage channel D2).
[0076] In the above embodiment, a configuration was described in which the first drainage channel D1 (or the second drainage channel D2) is formed by cutting out (or recessing) the first microbubble generation section 3. In another embodiment, the first drainage channel D1 (or the second drainage channel D2) may be formed by recessing the main body case 10 from the inner surface 10a toward the radially outward direction of the central axis A.
[0077] In the above embodiment, a configuration was described in which the microbubble generator 2 is installed such that the direction toward the upstream side along the central axis A is vertically upward, and the direction toward the downstream side along the central axis A is vertically downward. In another embodiment, the microbubble generator 2 may not be installed in this manner. For example, the microbubble generator 2 may be arranged such that the direction toward the upstream side along the central axis A is inclined within an angular range of -90° to 90° relative to the vertically upward direction, and the direction toward the downstream side along the central axis A is inclined within an angular range of -90° to 90° relative to the vertically downward direction. In this case, either the first drainage channel D1 or the second drainage channel D2 may be arranged to connect to the vicinity of the bottom of the gap space S. In this case as well, when the microbubble generator 2 is drained, almost all of the water in the gap space S flows into the first drainage channel D1 or the second drainage channel D2.
[0078] In the above embodiment, a configuration with two drainage channels was described. In another embodiment, three or more drainage channels may be provided. Alternatively, only one drainage channel may be provided.
[0079] In the above embodiment, the number of each of the multiple second microbubble generation sections 5, multiple outer venturi channels 34, multiple slits 4, and multiple vane sections 56 may be changed as appropriate. Also, although it is written as "multiple," there may be just one.
[0080] (Correspondence) In one or more embodiments, the microbubble generator 2 comprises a main body case 10 having an inlet 12 and an outlet 14, and a first microbubble generating unit 3 housed in the main body case 10. The first microbubble generating unit 3 comprises a body portion 30 extending between the inlet 12 and the outlet 14, venturi channels 32 and 34 passing through the inside of the body portion 30 and communicating between the inlet 12 and the outlet 14, an upstream fitting portion 36 connected to the upstream end of the body portion 30 and having an outer surface 36a shaped to substantially fit onto the inner surface 10a of the main body case 10 when the inside of the main body case 10 is viewed from the upstream side, and a downstream fitting portion 38 connected to the downstream end of the body portion 30 and having an outer surface 38a shaped to substantially fit onto the inner surface 10a of the main body case 10 when the inside of the main body case 10 is viewed from the downstream side. The venturi channels 32 and 34 include narrowing channels 322 and 342 whose channel diameter decreases as they move from the upstream side to the downstream side, and widening channels 324 and 344 located downstream of the narrowing channels 322 and 342, whose channel diameter widens as they move from the upstream side to the downstream side. Inside the main body case 10, there is a gap space S formed between the inner surface 10a of the main body case 10 and the narrowing outer surface 302 and the widening outer surface 304 (an example of the outer surface of the body), between the upstream fitting portion 36 and the downstream fitting portion 38, and a first drain channel D1 and a second drain channel D2 (an example of one or more drain channels) that connect the gap space S to the outlet portion 14.
[0081] According to the above configuration, when the microbubble generator 2 is drained so that the water inside the main case 10 drains from the inlet 12 to the outlet 14, the water in the gap space S drains to the outlet 14 through the first drainage channel D1 or the second drainage channel D2. Therefore, the drainage performance of the gap space S can be improved.
[0082] In one or more embodiments, there are multiple drainage channels, comprising a first drainage channel D1 and a second drainage channel D2.
[0083] According to the above configuration, when the water draining device 2 is performed so that the water inside the main case 10 drains from the inlet 12 to the outlet 14, the water in the gap space S drains out to the outlet 14 from two locations. Therefore, the water draining performance of the gap space S can be further improved.
[0084] In one or more embodiments, at least one of the first drainage channel D1 and the second drainage channel D2 is connected to the vicinity of the bottom of the gap space S with its vertically downward direction.
[0085] Normally, when draining water from the microbubble generator 2, the water in the gap space S drains downward due to gravity. For this reason, water tends to accumulate, especially near the bottom of the gap space S, after draining the microbubble generator 2. With the above configuration, the first drainage channel D1 and the second drainage channel D2 (an example of at least one drainage channel) are connected to the gap space S near the bottom of the gap space S, with their downward vertical orientation. Therefore, the accumulation of water in the gap space S after draining the microbubble generator 2 can be reliably suppressed.
[0086] In one or more embodiments, the microbubble generator 2 is housed in a main body case 10 and further comprises a second microbubble generator 5 located between the first microbubble generation unit 3 and the outlet unit 14. The second microbubble generator 5 comprises a shaft portion 52 extending in a direction from upstream to downstream, an outer peripheral portion 54 surrounding the radially outer side of the shaft portion 52, a plurality of blade portions 56 located between the shaft portion 52 and the outer peripheral portion 54, which generate a swirling flow that flows clockwise relative to the shaft portion 52 (for example, in a predetermined swirling direction), and a swirling flow path 64 passing through the gaps between the shaft portion 52, the outer peripheral portion 54, and the plurality of blade portions 56.
[0087] According to the above configuration, a second microbubble generation section 5 is further provided downstream of the first microbubble generation section 3. Therefore, the water flowing into the inlet section 12 not only passes through the venturi channels 32 and 34 of the first microbubble generation section 3, but also through the swirling channel 64 of the second microbubble generation section 5. In this case, the microbubbles generated in the first microbubble generation section 3 become even finer due to the shear force caused by the swirling flow generated in the second microbubble generation section 5, and the quantity of microbubbles increases. According to the above configuration, a large amount of microbubbles can be generated.
[0088] In one or more embodiments, the main body case 10 has a substantially cylindrical inner surface 10a extending in the direction from upstream to downstream. The first microbubble generating section 3 is formed of resin. The body 30 has a diameter-reducing outer surface 302 in the portion where the diameter-reducing channels 322 and 342 are provided, which decreases in diameter as it moves from upstream to downstream. The body 30 has an expanding outer surface 304 in the portion where the diameter-expanding channels 324 and 344 are provided, which expands in diameter as it moves from upstream to downstream.
[0089] When resin is used for the first microbubble generation section 3, it is common for the first microbubble generation section 3 to be formed by injection molding. In this case, if the wall thickness of the first microbubble generation section 3 (especially the body section 30) is large, quality defects of the first microbubble generation section 3 are likely to occur. In contrast, with the above configuration, the wall thickness of the body section 30 can be reduced. Therefore, when the first microbubble generation section 3 is formed by injection molding, the quality of the first microbubble generation section 3 can be improved. Furthermore, with the above configuration, the volume of the gap space S is increased, so the effect of improving the liquid drainage performance of the gap space S according to this invention is more pronounced.
[0090] In one or more embodiments, the first microbubble generating section 3 is provided with a first notch 6 and a second notch 8 (example of one or more notches) formed by cutting out a portion of the downstream fitting section 38 from the downstream side toward the upstream side. The first notch 6 and the second notch 8 function as a first drainage channel D1 and a second drainage channel D2.
[0091] According to the above configuration, the first water drainage channel D1 and the second water drainage channel D2 can be formed by partially processing the first microbubble generation section 3. Therefore, the first water drainage channel D1 and the second water drainage channel D2 can be easily formed.
[0092] In one or more embodiments, the first microbubble generating section 3 is provided with a first recess 306 and a second recess 308 (examples of one or more recesses) having a shape that is recessed inward from the enlarged outer surface 304. The first recess 306 and the second recess 308 are connected to the first notch 6 and the second notch 8.
[0093] With the above configuration, the first recess 306 and the second recess 308 make it easier for water in the gap space S to be guided to the first notch 6 and the second notch 8. In other words, water in the gap space S is easily guided to the first drainage channel D1 and the second drainage channel D2. Therefore, the water drainage performance of the gap space S can be further improved.
[0094] In one or more embodiments, the water heater 100 includes a microbubble generator 2.
[0095] According to the above configuration, the microbubble generating device 2 provided in the water heater 100 can improve the water drainage performance of the gap space S.
[0096] In one or more embodiments, the dishwasher 510 includes a microbubble generator 2.
[0097] According to the above configuration, the water drainage performance of the gap space S can be improved in the microbubble generating device 2 of the dishwasher 510.
[0098] The technical elements described herein or in the drawings demonstrate technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated herein or in the drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [Explanation of Symbols]
[0099] 2: Microbubble Generator 3: First microbubble generation section 4: Slit 5: Second microbubble generation section 6: First notch 8: Second notch 10: Main unit case 10a: Inner surface 10b: Positioning member 12:Inflow part 14: Outlet 30: Torso 32: Inner Venturi channel 34: Outer Venturi channel 36: Upstream mating section 36a: Outer surface of the upstream fitting portion 38: Downstream mating section 38a: Outer surface of the downstream fitting portion 42:First end 44:Second end 52: Shaft 54: Outer perimeter 56: Feather part 64: Swirling flow path 66: Fitting protrusion 68: Fitting recess 100: Water heater 104: Water supply pipe 106: First drain valve 108: Water volume sensor 110: Water volume servo 112: Water heater controller 114:Heat exchanger 116: Gas burner 118: Combustion fan 122: Hot water pipe 122a: First hot water supply pipe 122b: Second hot water supply pipe 124: Hot water thermistor 126: Second drain valve 302: Reduced diameter outer surface 304: Expanded diameter outer surface 306: First recess 306a: 1st slope part 306b: 1st bottom 308: Second recess 308a: 2nd slope part 308b: 2nd bottom 322: Inner diameter reduced flow path 324:Inner expanded diameter channel 342: Outer diameter reduced flow path 344:Outer enlarged diameter channel 382: Engagement convex part 510: Dishwasher 511: 1st discharge port 512: Main unit 514: Washing tank 515: Door 516: Control Panel 517: Leftover food filter 518: Exhaust path 519: Tableware 520: Cleaning nozzle 521: Upper nozzle 521a: Injection port 522: Lower nozzle 522a: Injection port 523: Tower nozzle section 524: Horizontal nozzle section 524a: Injection port 527: Pump 528: Impeller 530: Heater 531: Suction recess 532: First suction channel 533: Back wall 534: Drain hose 535:Second discharge port 536: Drainage channel 537: Air venting path 538: Drain check valve 539: Bottom 540: Water supply hose 541: Water supply valve 542: 1st water supply channel 543:Second water supply channel 544: Entrance 545: Water level detection unit 550: Water level path 551: Back wall 552: Drying fan 553: Fan 554: Washing water level 555: Thermistor 556: Lid 560: Washing machine controller 561: Dish basket 563: Drying route 564 :Exit 572 :Aperture 574: Second suction channel 576: Flow path switching valve A: Central axis D1: First drainage channel D2: Second drainage channel S: Gap space
Claims
1. A main body case having an inlet and an outlet, A microbubble generating device comprising a first microbubble generating unit housed in the main body case, The first microbubble generation unit is, A body portion extending between the inlet portion and the outlet portion, A venturi channel that passes through the inside of the body and connects the inlet and outlet, An upstream fitting portion is connected to the upstream end of the body and has an outer surface that is shaped to substantially fit into the inner surface of the main body case when the inside of the main body case is viewed from the upstream side, A downstream fitting portion is connected to the downstream end of the body and has an outer surface that is shaped to substantially fit into the inner surface of the main body case when the inside of the main body case is viewed from the downstream side, It is equipped with, The aforementioned Venturi channel is A narrowing channel, where the channel diameter decreases as you move from the upstream side to the downstream side, It is provided downstream of the aforementioned narrowed-diameter channel, and includes an expanding-diameter channel whose diameter widens as it moves from the upstream side to the downstream side, The interior of the main body case is provided with a gap space formed between the inner surface of the main body case and the outer surface of the body portion, between the upstream fitting portion and the downstream fitting portion, and one or more drainage channels that connect the gap space to the outlet portion. A microbubble generating device in which liquid that has entered the gap space from between the inner surface of the main body case and the outer surface of the upstream fitting portion, and / or liquid that has entered the gap space from between the inner surface of the main body case and the outer surface of the downstream fitting portion, is drained to the outlet through one or more drainage channels.
2. The microbubble generating apparatus according to claim 1, wherein the drainage channels are a plurality of channels, comprising a first drainage channel and a second drainage channel.
3. The microbubble generating device according to claim 1 or 2, wherein at least one of the one or more drainage channels is connected to the gap space near the bottom of the gap space, with its vertically downward direction being downward.
4. The main body case is housed in the aforementioned main body case and further comprises a second microbubble generating section located between the first microbubble generating section and the outflow section. The second microbubble generation unit is, A shaft portion extending in the direction from the upstream side to the downstream side, The outer circumference surrounding the radially outer side of the shaft portion, A plurality of vane portions are provided between the shaft portion and the outer circumference portion, and generate a swirling flow that flows in a predetermined swirling direction relative to the shaft portion, A microbubble generating device according to any one of claims 1 to 3, comprising a swirling channel passing through the gaps between the shaft portion, the outer circumference portion, and the plurality of blade portions.
5. The main body case has an inner surface that is substantially cylindrical in shape and extends in the direction from the upstream side to the downstream side. The first microbubble generating section is formed of resin, The body portion has a diameter-reducing outer surface that decreases in diameter from the upstream side to the downstream side in the portion where the diameter-reducing flow path is provided. The microbubble generating apparatus according to any one of claims 1 to 4, wherein the body portion has an expanding outer surface that expands in diameter from the upstream side to the downstream side in the portion where the expanding channel is provided.
6. The first microbubble generating section is provided with one or more notches formed by cutting out a part of the downstream fitting section from the downstream side toward the upstream side. The microbubble generating device according to any one of claims 1 to 5, wherein the one or more notches function as the one or more liquid drainage channels.
7. The first microbubble generating section is provided with one or more recesses having a shape that is concave from the outer surface of the body toward the inside, The microbubble generating apparatus according to claim 6, wherein the one or more recesses are connected to the one or more notches.
8. A water heater equipped with a microbubble generating device according to any one of claims 1 to 7.
9. A dishwasher equipped with a microbubble generating device according to any one of claims 1 to 7.