Stirring device

Abstract

To generate fine bubbles efficiently.SOLUTION: A stirring device 200 includes: a stirring member 210 having circular disc parts 216a to 216d which are provided so as to be rotatable around a vertical axis C in a passage 231 where a liquid and a gas flow and has a substantially plate shape; and a motor which rotationally drives the stirring member 210. In the circular disc parts 216a to 216d, a plurality of openings 218 are provided so as to shear the liquid and the gas.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present invention relates to an agitator that generates fine bubbles by agitating liquid and gas. [Background technology]

[0002] Conventionally, as this type of device, a device that uses a plate-shaped stirring blade to generate fine bubbles is known (see, for example, Patent Document 1). In the device described in Patent Document 1, air bubbles are supplied from below to a tank in which liquid is stored, the rising air bubbles are made into fine bubbles by a fixed stirring blade, and the fine bubbles that rise to the vicinity of the liquid surface are pushed downward by a moving stirring blade. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 5-85498 Summary of the Invention [Problem to be solved by the invention]

[0004] However, it is difficult to efficiently generate fine bubbles simply by using a plate-shaped stirring blade to finely divide air bubbles, as in the device described in Patent Document 1. [Means for solving the problem]

[0005] The stirring device according to one aspect of the present invention includes a stirring member having a substantially plate-shaped disk rotatably disposed about a vertical axis in a passage through which liquid and gas flow, and a motor for rotating the stirring member. The disk is provided with a plurality of openings so as to shear the liquid and the gas. Effect of the Invention

[0006] According to the present invention, fine bubbles can be generated efficiently. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a cross-sectional view showing an example of a reforming reactor and a stirring device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of the reforming reactor taken along line II-II in FIG. [Diagram 3] FIG. 2 is a cross-sectional view of the reforming reactor taken along line III-III in FIG. [Figure 4] FIG. 2 is a diagram for explaining the reaction channel in FIG. 1. [Diagram 5] FIG. 2 is a diagram for explaining a heat transfer medium flow path in FIG. 1. [Figure 6] FIG. 2 is a diagram for explaining a heat transfer medium discharge flow path in FIG. 1; [Figure 7] 2 is a cross-sectional view for explaining a downward flow path and a return flow path in FIG. 1. [Figure 8] 2 is a cross-sectional view for explaining a downward flow passage and a reformed fuel discharge flow passage in FIG. 1. [Figure 9] FIG. 2 is a diagram for explaining a downward flow path in FIG. 1; [Figure 10] FIG. 2 is a perspective view of the lower plate of FIG. 1, with a portion cut away, as viewed from above. [Figure 11] 2 is a perspective view of the lower plate of FIG. 1, with a portion cut away, as viewed from below. FIG. [Figure 12] FIG. 2 is a partially enlarged view of the stirring member and its surroundings in FIG. [Figure 13A] 13 is a cross-sectional view of the first disk member taken along line XIIIA-XIIIA in FIG. 12 . [Figure 13B] 13 is a cross-sectional view of the second disk member taken along line XIIIB-XIIIB in FIG. 12 . [Figure 13C] 13 is a cross-sectional view of the third disk member taken along line XIIIC-XIIIC in FIG. 12 . [Figure 13D] 13 is a cross-sectional view of the fourth disk member taken along line XIIID-XIIID in FIG. 12 . [Figure 14] FIG. 2 is a cross-sectional view of the lower plate taken along line XIV-XIV in FIG. 1 . [Figure 15] 1B is a cross-sectional view of the upper plate taken along line XV-XV in FIG. 1; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 15. An agitation device according to an embodiment of the present invention generates fine bubbles by agitating liquid and gas. In particular, an agitation device that generates fine bubbles by agitating a reaction liquid and gas and supplies the bubbles from below to a reactor in which a gas-liquid reaction takes place will be described below. The reactor is, for example, a reforming reactor that is applied to a compression ignition engine mounted on a vehicle and reforms the fuel supplied to the engine from a fuel tank by an oxidation reaction.

[0009] The average temperature of the Earth is kept warm enough for living things by greenhouse gases in the atmosphere. Specifically, greenhouse gases absorb some of the heat radiated from the Earth's surface, which is heated by sunlight, into space, and re-radiate it back to the Earth's surface, thereby keeping the atmosphere warm. When the concentration of greenhouse gases in the atmosphere increases, the average temperature of the Earth rises (global warming). The concentration of carbon dioxide in the atmosphere, which is one of the greenhouse gases that contributes most to global warming, is determined by the balance between the carbon fixed on the ground or in the earth as plants or fossil fuels, and the carbon present in the atmosphere as carbon dioxide. For example, when carbon dioxide in the atmosphere is absorbed by plants through photosynthesis during their growth, the concentration of carbon dioxide in the atmosphere decreases, and when carbon dioxide is released into the atmosphere through the burning of fossil fuels, the concentration of carbon dioxide in the atmosphere increases. In order to prevent global warming, it is necessary to replace fossil fuels with renewable energy sources such as solar and wind power, or renewable fuels derived from biomass, and to reduce carbon emissions.

[0010] As such a renewable fuel, low-octane gasoline obtained by FT (Fischer-Tropsch) synthesis is becoming more and more popular. Low-octane gasoline has high ignition properties and can be used in compression ignition engines, but it is still in the process of being popular and is not sold in some areas. On the other hand, normal octane gasoline for spark ignition engines, which is currently in widespread use, has low ignition properties and cannot be used in compression ignition engines as it is. By installing a reforming reactor in the fuel supply path from the fuel tank to the engine injector and reforming the fuel as needed, both low-octane gasoline and normal octane gasoline can be compression ignited in a single engine.

[0011] FIG. 1 is a cross-sectional view showing an example of a reforming reactor 100 and an agitation device 200 according to an embodiment of the present invention. The agitation device 200 generates fine bubbles by agitating liquid and gas. In the following, an example in which fuel and air are agitated to generate fine bubbles, and fuel containing the generated fine bubbles is supplied to the reforming reactor 100 will be described in particular. FIG. 2 is a cross-sectional view of the reforming reactor 100 taken along line II-II in FIG. 1. FIG. 3 is a cross-sectional view of the reforming reactor 100 taken along line III-III in FIG. 1. In the following, a direction extending radially from a vertical axis C is defined as a radial direction, and a direction along a circumference of a circle centered on the vertical axis C is defined as a circumferential direction.

[0012] As shown in FIG. 1, the reforming reactor 100 has an upper piece 100A and a lower piece 100B formed using a metal material having high thermal conductivity. The upper piece 100A and the lower piece 100B can be formed, for example, by additive manufacturing (AM). As shown in FIG. 1, the upper piece 100A and the lower piece 100B are fixed to each other by bolts and nuts (not shown) via a seal ring (not shown). The lower piece 100B of the reforming reactor 100 is formed with a reaction flow path 10 through which a fuel flows and a heat medium flow path 20 through which a heat medium flows. As shown in FIGS. 1 to 3, the reaction flow path 10 and the heat medium flow path 20 are each configured in a band shape so as to extend in a width direction parallel to a vertical axis C and in a length direction perpendicular to the width direction, and are configured in a spiral shape around the vertical axis C, and are arranged alternately in the radial direction. As shown in FIG. 1, the upper and lower end faces of the reaction channel 10 are open, and the upper and lower end faces of the heat transfer medium channel 20 are closed.

[0013] 4 is a diagram for explaining the reaction flow channel 10. As shown in FIGS. 1 and 4, the height of the upper end surface of the reaction flow channel 10 is uniform over the entire radial area. Pre-reformed fuel containing finely bubbled air is supplied to the reaction flow channel 10 from below over the entire radial area by the agitator 200. The fine bubbles supplied to the reaction flow channel 10 flow upward along the width direction of the reaction flow channel 10.

[0014] The ignition ability of fuels whose main component is hydrocarbons can be improved by oxidizing and reforming them using a catalyst such as N-hydroxyphthalimide (NHPI) to generate peroxides. Specifically, hydrogen atoms from NHPI are easily removed by oxygen molecules to generate phthalimide-N-oxyl (PINO) radicals. The PINO radicals remove hydrogen atoms from the hydrocarbons (RH) contained in the fuel to generate alkyl radicals (R·). The alkyl radicals combine with oxygen molecules to generate alkylperoxy radicals (ROO·). The alkylperoxy radicals remove hydrogen atoms from the hydrocarbons contained in the fuel to generate alkylhydroperoxides (ROOH), which are peroxides. [ka]

[0015] The reaction flow channel 10 functions as a reactor (reaction field) where the fuel reacts with oxygen in the air (oxidation reaction, fuel reforming reaction, gas-liquid reaction) to produce reformed fuel. A catalyst such as a powdered or wall-supported NHPI catalyst is provided in the reaction flow channel 10. The fuel supplied to the reaction flow channel 10 and the oxygen contained in the air (fine bubbles) come into contact with the catalyst provided in the reaction flow channel 10. This promotes the oxidation reforming reaction of the fuel throughout the entire radial area of ​​the reaction flow channel 10.

[0016] As shown in FIG. 2, the gap g1 between the inner wall surfaces of the reaction flow channel 10, more specifically, between the inner end surface and the outer end surface of the reaction flow channel 10 in the radial direction, is formed to be equal to or less than twice the quenching distance. This ensures that the inner wall surface of the reaction flow channel 10 is always within the quenching distance from the reactant, thereby improving the safety of the reforming reactor 100. To further improve safety, the reforming reactor 100 may be formed so that the gap g1 is equal to or less than the maximum safe gap. By configuring the reaction flow channel 10, which is the reaction field where the oxidation reaction of the fuel progresses, with the maximum safe gap, the flame is immediately extinguished even if it invades from an adjacent device, for example, so that the safety of the reforming reactor 100 can be further improved.

[0017] FIG. 5 is a diagram for explaining the heat medium passage 20. As shown in FIG. 1 and FIG. 5, the upper end surface of the heat medium passage 20 is formed with an upward inclination toward the inside in the radial direction. A heat medium supply passage 21 that supplies a heat medium to the vicinity of the lower end of the outermost diameter part of the heat medium passage 20 is formed in the lower piece 100B of the reforming reactor 100. The heat medium supply passage 21 extends with a downward inclination toward the inside in the radial direction so as to communicate the vicinity of the lower end of the outermost diameter part of the heat medium passage 20 with the external space. Engine cooling water as a heat medium is supplied to the heat medium passage 20 from an engine (not shown) through the heat medium supply passage 21.

[0018] 1, 2 and 5, a heat medium discharge passage 22 that discharges the heat medium from the innermost diameter part of the heat medium passage 20 is formed in the lower piece 100B of the reforming reactor 100. The heat medium discharge passage 22 protrudes upward from the lower end surface of the heat medium passage 20 and is formed in a cylindrical shape centered on the vertical axis C. The heat medium passage 20 and the heat medium discharge passage 22 provided in the heat medium passage 20 are separated by a cylindrical partition wall 23.

[0019] FIG. 6 is a diagram for explaining the heat medium discharge passage 22, and shows a front view of the partition wall 23. As shown in FIGS. 2, 5 and 6, the partition wall 23 is provided with a plurality of (four in the illustrated example) communication holes 24 having different heights from the lower end surface of the heat medium passage 20, and the heat medium is discharged from the heat medium passage 20 through the communication holes 24 and the heat medium discharge passage 22. The engine coolant discharged as the heat medium through the heat medium discharge passage 22 is returned to the engine. The partition wall 23 is formed such that the plurality of communication holes 24 are larger toward the bottom and smaller toward the top. Such a plurality of communication holes 24 are provided at a plurality of locations in the circumferential direction (two locations in the illustrated example).

[0020] 1, in the lower piece 100B of the reforming reactor 100, a descending passage 30 through which reformed fuel (reformed fuel) flows is formed above the heat transfer passage 20. That is, the descending passage 30 is also configured in a spiral shape centered on the vertical axis C, and is arranged alternately with the reaction passages 10 in the radial direction.

[0021] 7 and 8 are cross-sectional views for explaining the descending flow passage 30. As shown in FIG. 1, FIG. 7 and FIG. 8, the upper end surface of the descending flow passage 30 is opened so as to communicate with the upper end surface of the reaction flow passage 10. The height of the upper end surface of the reaction flow passage 10 and the height of the upper end surface of the descending flow passage 30 coincide with the height of the partition wall 31 separating the reaction flow passage 10 and the descending flow passage 30 (and the heat transfer medium flow passage 20), and are the same with each other over the entire radial range. The heat transfer medium flow passage 20 and the descending flow passage 30 are separated by the partition wall 32, and the height of the upper end surface of the heat transfer medium flow passage 20, the height of the lower end surface of the descending flow passage 30, and the height of the partition wall 32 are approximately the same with each other over the entire radial range. The lower end surface of the descending flow passage 30 is located above the lower end surfaces of the reaction flow passage 10 and the heat transfer medium flow passage 20 over the entire radial range, and is formed with a downward gradient toward the outside in the radial direction.

[0022] The upper piece 100A of the reforming reactor 100 is formed with a first protruding portion 40 and a second protruding portion 50 protruding downward from the upper inner wall surface. The first protruding portion 40 is formed corresponding to the reaction flow passage 10, and protrudes from the upper inner wall surface of the reaction flow passage 10 toward the reaction flow passage 10 over the entire radial range. The second protruding portion 50 is formed corresponding to the descending flow passage 30 (and the heat transfer passage 20), and protrudes from the upper inner wall surface of the descending flow passage 30 toward the descending flow passage 30 over the entire radial range.

[0023] As shown in Fig. 7 and Fig. 8, the gap g2 between the first protrusion 40 and the second protrusion 50, more specifically, between the outer end surface of the first protrusion 40 and the inner end surface of the second protrusion 50 in the radial direction, is also configured to be less than twice the quenching distance or less than the maximum safe gap. Similarly, the gap g3 between the outer end surface of the second protrusion 50 and the inner end surface of the first protrusion 40 is also configured to be less than twice the quenching distance or less than the maximum safe gap. In addition, the gap g4 between the upper end surface of the reaction flow channel 10 and the lower end surface of the first protrusion 40, and the gap g5 between the lower end surface of the descending flow channel 30 and the lower end surface of the second protrusion 50 are also configured to be less than twice the quenching distance or less than the maximum safe gap.

[0024] The liquid level (gas-liquid separation surface) L1 of the reformed fuel is adjusted to be located between the upper end surfaces of the reaction flow channel 10 and the descending flow channel 30 and the lower end surface of the first protruding portion 40. The space (gas-liquid separation space) SP1 from the gas-liquid separation surface L1 to the upper inner wall surface of the upper piece 100A has a spiral labyrinth shape due to the first protruding portion 40 and the second protruding portion 50. As shown in FIG. 1, the upper piece 100A of the reforming reactor 100 has a gas discharge flow channel 33 for discharging gas from the reaction flow channel 10. The gas discharge flow channel 33 communicates with the reaction flow channel 10 through the gas-liquid separation space SP1. The air supplied to the reaction flow channel 10 rises in the reaction flow channel 10 and is used for the reforming reaction, and then is discharged from the gas-liquid separation surface L1 to the gas-liquid separation space SP1. After the liquid is separated in the gas-liquid separation space SP1, the air is discharged to the outside space through the gas discharge flow channel 33. The air discharged through the gas discharge passage 33 is supplied to the intake port of the engine and is drawn into the combustion chamber of the engine together with fresh air.

[0025] FIG. 9 is a diagram for explaining the descending flow passage 30. As shown in FIG. 1 and FIG. 7 to FIG. 9, the lower end surface of the descending flow passage 30 is formed with a downward inclination toward the radially outward side. As shown in FIG. 1, FIG. 2, and FIG. 7 to FIG. 9, the lower piece 100B of the reforming reactor 100 is formed with a return flow passage 60 for returning the reformed fuel at the lower end of the outermost diameter part of the reaction flow passage 10. As shown in FIG. 7 and FIG. 8, the gap g6 between the inner wall surfaces of the return flow passage 60, more specifically, between the inner end surface and the outer end surface of the return flow passage 60 in the radial direction, is also configured to be equal to or less than twice the quenching distance or equal to or less than the maximum safe gap.

[0026] As shown in Figs. 1, 2 and 7 to 9, the return flow path 60 includes a vertical flow path 60a, a horizontal flow path 60b and an inclined flow path 60c. The vertical flow path 60a extends vertically from near the upper end to near the lower end of the lower piece 100B at the outermost diameter portion of the reaction flow path 10 and the heat transfer medium flow path 20, i.e., on the outer diameter side of the outermost diameter portion of the partition wall 31. The horizontal flow path 60b extends horizontally at the upper end surface of the outermost diameter portion of the partition wall 31 so as to communicate the outermost diameter portion of the descending flow path 30 and the upper end surface of the vertical flow path 60a. The inclined flow path 60c extends radially inwardly at a downward inclination so as to communicate the lower end of the vertical flow path 60a and the lower end of the outermost diameter portion of the reaction flow path 10.

[0027] 1 and 8, a reformed fuel discharge passage 70 that discharges a portion of the reformed fuel from the outermost diameter portion of the descending passage 30 is formed in the lower piece 100B of the reforming reactor 100. The reformed fuel discharge passage 70 extends horizontally near the upper end of the return passage 60, more specifically, at a position slightly lower than the horizontal passage 60b, so as to communicate between the vertical passage 60a and the external space.

[0028] 4 and 7 to 9, the reformed fuel that has been reformed while flowing upward along the width direction of the reaction channel 10 overflows from the upper end surface of the reaction channel 10, passes over the partition wall 31, flows into the descending channel 30, and flows radially outward along the length direction of the descending channel 30. A portion of the reformed fuel that has reached the outermost diameter portion of the descending channel 30 is discharged via the reformed fuel discharge channel 70, and the remainder is returned via the return channel 60 to the lower end of the outermost diameter portion of the reaction channel 10.

[0029] In order to improve the reforming rate in the reaction flow channel 10 of such a reforming reactor 100, i.e., the reaction rate of the gas-liquid reaction, it is necessary to supply a fuel (liquid) containing a sufficient amount of fine bubbles to the reaction flow channel 10. As a method for supplying a liquid containing fine bubbles, a method for generating fine bubbles by supplying a gas into a liquid through a filter made of a porous material such as a sintered body or a foam body is also known. However, with this method, if the filter has uneven pores or gaps, large bubbles are preferentially generated from the large pores or gaps, making it difficult to generate sufficient fine bubbles. In particular, when the volume of the filter becomes large, the influence of uneven pores and gaps becomes greater, making it difficult to generate fine bubbles at a sufficient flow rate.

[0030] Known methods that do not use a filter include a method of swirling a liquid at high speed and generating fine bubbles by shearing caused by the swirling flow, and a method of generating fine bubbles by cavitation by rapidly contracting and expanding a flow path. However, these methods are premised on a relatively large liquid flow rate, and are difficult to apply when the liquid flow rate is relatively small, such as a fuel flow rate according to an engine's required output. Therefore, in this embodiment, the stirring device 200 is configured as follows so that fine bubbles can be efficiently generated by stirring, thereby making it possible to supply fuel (liquid) containing sufficient fine bubbles to the reforming reactor 100 even when the flow rate is relatively small.

[0031] As shown in FIG. 1, the stirring device 200 mainly includes a stirring member 210, a motor 220 that rotates the stirring member 210, a lower plate 230 that houses the stirring member 210, and an upper plate 240 interposed between the lower plate 230 and the reforming reactor 100.

[0032] The stirring member 210 is rotatably disposed about a vertical axis C in a passage 231 formed in the lower plate 230 through which liquid and gas flow, and is connected to a motor 220 by a so-called magnetic coupling so as to be rotated without contact.

[0033] More specifically, a substantially cylindrical shaft portion 211 centered on a vertical axis C is fixed to the lower plate 230 by press-fitting or the like so as not to rotate relative to the shaft portion 211. The stirring member 210 is provided on the outer circumferential surface of the shaft portion 211 so as to be rotatable relative to the shaft portion 211, and a spacer 210a is provided below the stirring member 210 so as to be rotatable relative to the shaft portion 211. The lower surface of the stirring member 210 and the upper surface of the spacer 210a are provided with projections and recesses, thereby fixing the stirring member 210 and the spacer 210a so as not to rotate relative to each other. An inner magnet 212 is fixed to the outer circumferential surface of the spacer 210a so as not to rotate relative to the spacer 210a. The spacer 210a and the inner magnet 212 are restricted from moving in the up and down direction by the lower end of the shaft portion 211. A partition wall portion 230a is provided below the lower plate 230 to form an accommodation chamber 213 that accommodates the shaft portion 211 below the stirring member 210, the spacer 210a, and the inner magnet 212. The partition wall portion 230a is fixed to, for example, the lower surface of the lower plate 230. The accommodation chamber 213 communicates with a passage 231 of the lower plate 230. The accommodation chamber 213 is filled with liquid that flows in from the passage 231 of the lower plate 230.

[0034] A cylindrical outer magnet 222 is fixed to the output shaft of the motor 220 via a motor joint 221, and rotates integrally with the output shaft of the motor 220. The outer magnet 222 is disposed on the outer diameter side of the accommodation chamber 213 so as to surround the accommodation chamber 213 (partition wall portion 230a). The space accommodating the motor 220 and the like is filled with an inert gas such as nitrogen gas to ensure safety.

[0035] When the motor 220 rotates, the outer magnet 222 rotates integrally with the motor 220. When the outer magnet 222 rotates, the inner magnet 212, the spacer 210a, and the stirring member 210 rotate integrally about the vertical axis C in the liquid in the accommodation chamber 213 due to attractive and repulsive forces.

[0036] Fig. 10 is a perspective view showing lower plate 230 as viewed from above, with a portion cut away. Fig. 11 is a perspective view showing lower plate 230 as viewed from below, with a portion cut away. Fig. 12 is a partial enlarged view of the periphery of stirring member 210 in Fig. 1. As shown in Figs. 1 and 10, lower plate 230 includes a case portion 232, a cover portion 233, a liquid supply flow path forming portion 234, a gas supply flow path forming portion 235, an annular flow path forming portion 236, a cylindrical portion 237, and an annular portion 238.

[0037] 1 and 12, the cylindrical portion 237 is formed in a substantially cylindrical shape centered on the vertical axis C so as to accommodate the vicinity of the upper end of the shaft portion 211. The annular portion 238 is formed in a substantially annular shape centered on the vertical axis C. The annular portion 238 of the lower plate 230 is fixed to the upper plate 240 by bolts and nuts (not shown) via a seal ring (not shown).

[0038] As shown in Figures 1, 10 and 12, the case portion 232 forms a conical surface 232a around the stirring member 210, centered on the vertical axis C which extends radially outward at an upward gradient facing the passage 231, toward the inner circumferential surface of the annular portion 238.

[0039] 1, 10, 11 and 12, the cover portion 233 is formed in a generally circular ring shape in plan view centered on the vertical axis C, and extends downward from the outer circumferential surface of the cylindrical portion 237 toward the outer diameter side so as to cover the upper surface of the stirring member 210. The lower surface 233a of the cover portion 233 is formed in a concave shape facing the upper surface of the stirring member 210. The cover portion 233 is formed with a protruding portion 233b that protrudes downward from the lower surface 233a toward the upper surface of the stirring member 210.

[0040] The liquid supply flow path forming portion 234 forms a liquid supply flow path 234a that supplies liquid (fuel) to the passage 231. The liquid supply flow path 234a extends radially inwardly at an upward gradient so as to communicate the passage 231 with the external space. The gas supply flow path forming portion 235 forms a gas supply flow path 235a that supplies gas (air) to the passage 231. The gas supply flow path 235a also extends radially inwardly at an upward gradient so as to communicate the passage 231 with the external space. The passage 231 is supplied with unreformed fuel from a fuel pump (not shown) via the liquid supply flow path 234a, and air is supplied from an air pump (not shown) via the gas supply flow path 235a.

[0041] As shown in FIG. 12, the gas supply passage 235a communicates with a space (retention space) SP3 between the upper surface of the stirring member 210 and the cover part 233 through a substantially cylindrical space (cylindrical space) SP2 along the outer circumferential surface of the cylindrical part 237. Similarly, the liquid supply passage 234a also communicates with the retention space SP3 through the cylindrical space SP2. As shown in FIG. 11 and FIG. 12, a spiral groove 237a is formed on the outer circumferential surface of the cylindrical part 237 so that the height of the cylindrical space SP2 spirally decreases along the rotation direction of the motor 220 (clockwise in the illustrated example when viewed from above) from the position where the liquid supply passage 234a and the gas supply passage 235a communicate with each other. In other words, the uppermost part of the cylindrical space SP2 where the liquid supply passage 234a and the gas supply passage 235a communicate with each other is the starting point or the most upstream of the passage 231. More specifically, the liquid supply flow path 234a communicates with the cylindrical space SP2 at the most upstream of the passage 231, and the gas supply flow path 235a communicates with the cylindrical space SP2 immediately downstream thereof.

[0042] As shown in FIG. 12, the stirring member 210 includes a base portion 214, a guide portion 215, a plurality of (four in the illustrated example) disk portions 216a to 216d, and a plurality of columnar portions 217. The base portion 214 is formed in a substantially plate-like shape and in a circular ring shape centered on a vertical axis C, and the stirring member 210 is disposed so that the inner peripheral surface of the base portion 214 faces the outer peripheral surface of the shaft portion 211. At least a part of the lower surface of the base portion 214 is provided with projections and recesses, and the projections and recesses of the lower surface of the base portion 214 are fitted into the projections and recesses of the upper surface of the spacer 210a, whereby the stirring member 210 and the spacer 210a are fixed so as not to rotate relative to each other and rotate together. The guide portion 215 is provided on the outer diameter side of the cylindrical portion 237 and extends cylindrically from the upper surface of the base portion 214 upward.

[0043] The disk parts 216a to 216d are extended horizontally from the outer peripheral surface of the guide part 215 toward the outer diameter side. The disk parts 216a to 216d are provided in a plurality of stages (four stages in the illustrated example) in the vertical direction. The diameters of the disk parts 216a and 216b in the upper two stages are smaller than the diameters of the disk parts 216c and 216d in the lower two stages. The plurality of columnar parts 217 are provided on the outer diameter side of the cylindrical part 237 so as to protrude upward from the upper surface of the base part 214 so as to connect the plurality of stages of disk parts 216a to 216d. The columnar part 217 protrudes upward from the upper surface of the uppermost disk part 216a. The liquid level L2 of the fuel supplied to the passage 231 is adjusted to be located near the lower surface of the uppermost disk part 216a, or at least lower than the upper surface of the uppermost disk part 216a.

[0044] FIG. 13A is a cross-sectional view of the disk portion 216 taken along line XIIIA-XIIIA in FIG. 12. FIG. 13B is a cross-sectional view of the disk portion 216 taken along line XIIIB-XIIIB in FIG. 12. FIG. 13C is a cross-sectional view of the disk portion 216 taken along line XIIIC-XIIIC in FIG. 12. FIG. 13D is a cross-sectional view of the disk portion 216 taken along line XIIID-XIIID in FIG. 12. As shown in FIG. 13A to FIG. 13D, the disk portions 216a to 216d are each provided with a plurality of openings 218 for shearing liquid and gas. More specifically, the plurality of openings 218 are provided in a lattice pattern in each of the disk portions 216a to 216d.

[0045] The grid of the disk parts 216a, 216c is defined by a plurality of straight lines extending in a first direction (X-axis direction in the illustrated example) and a plurality of straight lines extending in a second direction (Y-axis direction in the illustrated example) perpendicular to the first direction. It is defined by a plurality of straight lines extending in a third direction different from both the first direction and the second direction, and a plurality of straight lines extending in a fourth direction perpendicular to the third direction. That is, the third direction intersects with each of the first direction and the second direction at an angle greater than 0 degrees and smaller than 90 degrees, for example, 45 degrees, in a plan view. In other words, the plurality of disk parts 216a to 216d are arranged such that the phases of the openings 218 of the disk parts 216a, 216b, the disk parts 216b, 216c, and the disk parts 216c, 216d facing each other are shifted.

[0046] The fuel and air supplied to the cylindrical space SP2 via the liquid supply passage 234a and the gas supply passage 235a spirally descend along the groove 237a in the rotation direction of the motor 220, and flow into the retention space SP3 above the uppermost disk portion 216a. The fuel and air flowing into the retention space SP3 are drawn in by the columnar portion 217 protruding upward from the uppermost disk portion 216a of the agitating member 210 rotating in the rotation direction of the motor 220 and the opening 218 of the uppermost disk portion 216a, and are taken into the agitating member 210. In this way, by arranging the uppermost disk portion 216a above the liquid level L2 and by having the multiple columnar portions 217 protruding upward, the air staying in the retention space SP3 can be efficiently taken into the agitating member 210.

[0047] The fuel and air taken into the stirring member 210 flow downward along the outer peripheral surface of the guide portion 215 and flow toward the outer diameter side due to the centrifugal force of the rotation, while being sheared and stirred by the ends (angular cross sections, edges) of the multiple openings 218, thereby generating fine bubbles. More specifically, the multiple disk portions 216a to 216d are provided with multiple lattice-shaped openings 218, and the multiple openings 218 are formed so that the horizontal cross section (FIGS. 13A to 13D) and vertical cross section (FIG. 12) of each of the disk portions 216a to 216d have multiple angular cross sections. By forming the stirring member 210 in this way with a shape having many angular cross sections, fine bubbles can be generated efficiently. In this case, fine bubbles can be generated at a relatively low rotation speed compared to a case where the shape has many round cross sections formed by bending a wire or the like, and stirring resistance and energy consumption can be suppressed. In addition, it is possible to suppress the flow rate of the fuel and air supplied to the reforming reactor 100 from becoming excessive. Furthermore, by shifting the phases of the openings 218 of the opposing disk portions 216a to 216d, turbulence is generated between the opposing disk portions 216a to 216d, so that fine bubbles can be generated more efficiently.

[0048] FIG. 14 is a cross-sectional view of the lower plate 230 taken along line XIV-XIV in FIG. 1. As shown in FIGS. 10, 12, and 14, the annular flow passage forming portion 236 forms a plurality of annular flow passages 236a on a concentric circle centered on the vertical axis C from the outer circumferential surface of the cylindrical portion 237 to the inner circumferential surface of the annular portion 238 above the case portion 232 and radially outside the cover portion 233. More specifically, as shown in FIG. 14, the annular flow passage forming portion 236 includes a plurality of radial portions 236b extending radially from the outer circumferential surface of the cylindrical portion 237 to the inner circumferential surface of the annular portion 238, and a plurality of annular portions 236c provided on a concentric circle centered on the vertical axis C. The plurality of annular portions 236c are connected to each other via the plurality of radial portions 236b, and are connected to the outer circumferential surface of the cylindrical portion 237 and the inner circumferential surface of the annular portion 238.

[0049] 10 and 12, the annular portion 236c extends vertically from the upper surface of the lower plate 230 to above the case portion 232. The annular flow path 236a is formed between the opposing annular portions 236c, i.e., between the inner peripheral surface and the outer peripheral surface. The lower end surface of the annular portion 236c is located above the upper surface (conical surface 232a) of the case portion 232.

[0050] The fuel containing fine bubbles generated by the stirring member 210 flows to the outer diameter side due to the centrifugal force of the rotation, and is discharged radially outward from below the cover portion 233. The fuel containing fine bubbles discharged radially outward from below the cover portion 233 flows to the outermost diameter portion along the conical surface 232a due to the centrifugal force of the rotation, and flows upward along the annular flow path 236a and is rectified. This allows the fuel containing fine bubbles to circulate uniformly throughout the entire radial direction. In addition, the turbulence generated by the stirring by the stirring member 210 is attenuated by being rectified, and the flow rate of the fuel containing fine bubbles flowing upward can be suppressed.

[0051] FIG. 15 is a cross-sectional view of the upper plate 240 taken along line XV-XV in FIG. 1. As shown in FIGS. 1 to 3 and 15, the upper plate 240 has a spiral flow passage 240a that is spirally shaped and centered on the vertical axis C, corresponding to the reaction flow passage 10 of the reforming reactor 100. As shown in FIGS. 1, 14 and 15, the fuel containing fine bubbles that flows out from the upper end of the annular flow passage 236a is collected and flows into the spiral flow passage 240a of the upper plate 240. The fuel containing fine bubbles that flows into the spiral flow passage 240a flows upward along the spiral flow passage 240a, and is further straightened to further attenuate the turbulence caused by the stirring by the stirring member 210, and then flows into the reaction flow passage 10 of the reforming reactor 100. The rotation directions of the motor 220 and the stirring member 210 are determined so that the fuel containing fine bubbles flows toward the inner diameter side of the spiral flow passage 240a.

[0052] As shown in Fig. 12 to Fig. 15, the gap g7 in the cylindrical space SP2, the gap g8 between the protruding parts 233b of the cover part 233, the gap g9 between the opposing disk parts 216a to 216d, the gap g10 between the openings 218, the gap g11 between the conical surface 232a of the case part 232 and the lower end surface of the annular part 236c, the gap g12 in the annular flow passage 236a, and the gap g1 in the spiral flow passage 240a are all configured to be less than twice the quenching distance or less than the maximum safe gap. In this way, by configuring all the gaps g1, g7 to g12 in the passage 231 through which the fuel and air flow, to be less than twice the quenching distance or less than the maximum safe gap, the stirring device 200 can be enlarged as necessary while ensuring safety. More specifically, by increasing the number of stages and the diameter of the disk part 216 of the stirring member 210, a required amount of fine bubbles can be generated and supplied to the reforming reactor 100, etc.

[0053] When fine bubbles are generated using the stirring device 200 and fuel containing the fine bubbles is supplied to the reforming reactor 100, sufficient fine bubbles can be generated regardless of the fuel flow rate by appropriately changing other parameters while matching the fuel flow rate required by the reforming reactor 100. For example, the shape of the stirring member 210, the rotation speed of the motor 220, the supply flow rate of air, etc. can be changed as necessary.

[0054] According to this embodiment, the following advantageous effects can be obtained. (1) The agitator 200 includes an agitator 210 having substantially plate-shaped disk portions 216a-216d rotatably provided around a vertical axis C in a passage 231 through which liquid and gas flow, and a motor 220 that rotates the agitator 210 (FIG. 1). The disk portions 216a-216d are provided with a plurality of openings 218 so as to shear the liquid and gas (FIGS. 13A-13D). The ends of the disk portions 216a-216d in contact with the liquid and the ends of the plurality of openings 218 shear the liquid and gas, thereby efficiently generating fine bubbles.

[0055] (2) The multiple openings 218 are arranged in a lattice pattern (FIGS. 13A to 13D). In this case, the ends of each opening 218, i.e., the multiple corners of the lattice (four corners on each of the front and back in the illustrated example), can shear the liquid and gas more efficiently, thereby generating fine bubbles more efficiently.

[0056] (3) The multiple openings 218 are formed so that the horizontal and vertical cross sections of the disk portions 216a to 216d have multiple angular cross sections (FIGS. 12 and 13A to 13D). In this case, the ends of each opening 218, i.e., the multiple sides of the lattice (four sides on each of the front and back in the illustrated example), can shear the liquid and gas more efficiently, thereby generating fine bubbles more efficiently.

[0057] (4) The disk portion 216 has a cylindrical portion 217 that protrudes upward (FIGS. 1 and 12). This allows the gas remaining in the passage 231 above the disk portion 216 to be efficiently taken in, so that the liquid and gas can be sheared more efficiently, and fine bubbles can be generated more efficiently.

[0058] (5) The stirring member 210 has disk portions 216a and 216c, and disk portions 216b and 216d arranged opposite to the disk portions 216a and 216c (FIGS. 1 and 12). The disk portions 216a and 216c and the disk portions 216b and 216d are each provided with a plurality of openings 218 so as to shear the liquid and the gas (FIGS. 1 and 12). This allows the liquid and the gas to be sheared more efficiently, and fine bubbles to be generated more efficiently.

[0059] (6) The stirring member 210 has disk parts 216a and 216c, and disk parts 216b and 216d arranged opposite to the disk parts 216a and 216c (FIGS. 1 and 12). The disk parts 216a and 216c are provided with a plurality of lattice-shaped openings 218 defined by a plurality of straight lines extending in a first direction (X-axis direction) so as to shear the liquid and gas and a plurality of straight lines extending in a second direction (Y-axis direction) perpendicular to the first direction (FIGS. 13A and 13C). The disk parts 216b and 216d are provided with a plurality of lattice-shaped openings 218 defined by a plurality of straight lines extending in a third direction so as to shear the liquid and gas and a plurality of straight lines extending in a fourth direction perpendicular to the third direction (FIGS. 13B and 13D). The first straight lines and the third straight lines intersect at approximately 45 degrees in a plan view (FIGS. 13A to 13D). This generates turbulent flows between the opposing disk portions 216a, 216c and between the openings 218 of the disk portions 216a, 216c, making it possible to generate fine bubbles more efficiently.

[0060] (7) The agitating member 210 has multiple stages of disk portions 216a to 216d in the vertical direction (FIGS. 1 and 12). Of the multiple stages of disk portions 216a to 216d, the diameter of the uppermost disk portion 216a is smaller than the diameter of the lowermost disk portion 216d (FIGS. 13A and 13D). This allows the uppermost disk portion 216a to efficiently take in the gas remaining in the upper passage 231, more efficiently shear the liquid and gas, and more efficiently generate fine bubbles.

[0061] (8) The agitation device 200 includes a case portion 232 that faces the passage 231 and forms a conical surface 232a centered on the vertical axis C, which extends radially outwardly with an upward gradient about the vertical axis C, around the agitation member 210; a cover portion 233 that is substantially annular in plan view centered on the vertical axis C and covers the upper surfaces of the disk portions 216a to 216d and has a lower surface 233a formed in a concave shape facing the upper surfaces of the disk portions 216a to 216d; and a cover portion 233 that is substantially annular in plan view centered on the vertical axis C and is disposed above the case portion 232 and vertically. It further includes, radially outward of the cover portion 233 centered on the vertical axis C, an annular flow path forming portion 236 which forms a plurality of annular flow paths 236a on a concentric circle centered on the vertical axis C, a liquid supply flow path forming portion 234 which forms a liquid supply flow path 234a which supplies liquid to the passage 231 between the disc portions 216a to 216d and the cover portion 233, and a gas supply flow path forming portion 235 which forms a gas supply flow path 235a which supplies gas (FIGS. 1, 10 to 12, and 14).

[0062] As shown in FIG. 12, the gas remaining on the lower surface 233a of the case portion 233 of the passage 231 is taken into the stirring member 210 from the upper surfaces of the disk portions 216a to 216d. The liquid and gas taken into the stirring member 210 are sheared by a plurality of lattice-shaped openings 218 that are out of phase with each other, generating fine bubbles. The fine bubbles generated by the stirring member 210 are discharged to the outer diameter side of the cover portion 233 by the centrifugal force of the rotation of the stirring member 210. The fine bubbles discharged to the outer diameter side of the cover portion 233 flow to the outer diameter side along the conical surface 232a of the case portion 232 by the centrifugal force, and flow upward along the annular flow path 236a. This allows the fine bubbles to be uniformly dispersed throughout the entire radial direction.

[0063] In the above embodiment, an example in which the stirring device 200 is applied to the reforming reactor 100 has been described, but the stirring device may be any device that stirs liquid and gas to generate fine bubbles, and is not limited to the example.

[0064] The above description is merely an example, and the present invention is not limited to the above-mentioned embodiment and modifications, as long as the features of the present invention are not impaired. The above-mentioned embodiment and one or more modifications can be arbitrarily combined, and modifications can be combined with each other. [Explanation of symbols]

[0065] 10 reaction flow path, 20 heat medium flow path, 21 heat medium supply flow path, 22 heat medium discharge flow path, 23 partition wall, 24 communication hole, 30 down flow path, 31, 32 partition wall, 33 gas discharge flow path, 40 first protrusion, 50 second protrusion, 60 return flow path, 60a vertical flow path, 60b horizontal flow path, 60c inclined flow path, 70 reformed fuel discharge flow path, 100 reforming reactor, 100A upper piece, 100B lower piece, 200 stirring device, 210 stirring member, 210a spacer, 211 shaft portion, 212 inner magnet, 213 storage chamber, 214 base portion, 215 guide portion, 216a to 216d disc portion, 217 cylindrical portion, 218 opening, 220 motor, 221 motor joint, 222 Outer magnet, 230 lower plate, 230a partition wall portion, 231 passage, 232 case portion, 232a conical surface, 233 cover portion, 233a lower surface, 233b protrusion portion, 234 liquid supply flow passage forming portion, 235 gas supply flow passage forming portion, 236 annular flow passage forming portion, 236a annular flow passage, 236b radial portion, 236c annular portion, 237 cylindrical portion, 238 annular portion, 240 upper plate, 240a spiral flow passage, C vertical axis, g1 to g12 gap, L1 liquid surface (gas-liquid separation surface), L2 liquid surface, SP1 space (gas-liquid separation space), SP2 space (cylindrical space), SP3 space (retention space)

Claims

1. a stirring member having a substantially plate-shaped disk rotatably disposed about a vertical axis within a passage through which the liquid and the gas flow; a motor that rotates the stirring member; The agitation device, characterized in that the disk is provided with a plurality of openings for shearing the liquid and the gas.

2. 2. The mixing device according to claim 1, The agitation device, wherein the plurality of openings are arranged in a lattice pattern.

3. The stirring device according to claim 2, A mixing device according to claim 1, wherein the plurality of openings are formed so that the horizontal and vertical sections of the disk present a plurality of angular cross sections.

4. The stirring device according to any one of claims 1 to 3, The stirring device is characterized in that the disk has a protruding portion protruding upward.

5. The stirring device according to any one of claims 1 to 3, The stirring member has a first disk and a second disk disposed opposite to the first disk, A mixing device, characterized in that the first disk and the second disk are provided with a plurality of openings so as to shear the liquid and the gas, respectively.

6. The stirring device according to any one of claims 1 to 3, The stirring member has a first disk and a second disk disposed opposite to the first disk, The first disk is provided with a plurality of openings in a lattice shape defined by a plurality of first straight lines extending in a first direction so as to shear the liquid and the gas and a plurality of second straight lines extending in a second direction perpendicular to the first direction, the second disk is provided with a plurality of openings in a lattice shape defined by a plurality of third straight lines extending in a third direction so as to shear the liquid and the gas and a plurality of fourth straight lines extending in a fourth direction perpendicular to the third direction; The agitation device, wherein the first straight line and the third straight line intersect at a predetermined angle in a plan view.

7. 7. The stirring device according to claim 6, The stirring device is characterized in that the predetermined angle is approximately 45 degrees.

8. The stirring device according to any one of claims 1 to 3, The stirring member has a plurality of stages of disks in the vertical direction, A mixing device, characterized in that, among the multiple stages of discs, the diameter of the uppermost disc is smaller than the diameter of the lowermost disc.

9. The stirring device according to any one of claims 1 to 3, a case portion that is disposed around the stirring member and faces the passage, and that forms a conical surface centered on the vertical axis, the conical surface extending radially outwardly from the vertical axis at an upward gradient; a cover portion having a generally annular shape in a plan view centered on the vertical axis, the cover portion covering an upper surface of the disk and having a lower surface formed in a concave shape facing the upper surface; an annular flow passage forming portion that forms a plurality of annular flow passages on concentric circles centered on the vertical axis, the annular flow passage forming portion being located above the case portion and radially outside the cover portion centered on the vertical axis; a supply flow path forming portion that forms a supply flow path through which the liquid and the gas are supplied to the passage between the disk and the cover portion.

Images