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 a liquid and a gas. [Background technology]

[0002] A known example of this type of device is one that uses plate-shaped stirring blades to generate fine bubbles (see, for example, Patent Document 1). In the device described in Patent Document 1, bubbles are supplied from below to a tank containing liquid, the rising bubbles are converted into fine bubbles by a fixed stirring blade, and the fine bubbles that have risen to near 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 the bubbles, as in the device described in Patent Document 1. [Means for solving the problem]

[0005] One aspect of the present invention is an agitation device comprising: an agitation member having a substantially plate-shaped disk rotatably disposed about a vertical axis in a passage through which a liquid and a gas flow; and a motor for rotating the agitation member. The disk has a plurality of openings formed therein so as to shear the liquid and the gas. The agitation device further comprises, around the agitation member, a case portion forming a conical surface centered on the vertical axis that faces the passage and extends radially outward from the vertical axis at an upward gradient; a cover portion that covers the upper surface of the disk and has a concave lower surface facing the upper surface and is substantially annular in plan view centered on the vertical axis; an annular flow path forming portion that forms a plurality of annular flow paths on concentric circles centered on the vertical axis above the case portion and radially outward from the cover portion centered on the vertical axis; and a supply flow path forming portion that forms a supply flow path that supplies the liquid and the gas to the passage between the disk and the cover portion. 。 [Effects of the Invention]

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

[0007] [Figure 1] 1 is a cross-sectional view showing an example of a reforming reactor and a stirring device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the reforming reactor taken along line II-II in FIG. 1. [Figure 3] FIG. 2 is a cross-sectional view of the reforming reactor taken along line III-III in FIG. 1. [Figure 4] FIG. 2 is a diagram for explaining the reaction channel in FIG. 1. [Figure 5] FIG. 2 is a diagram for explaining the heat transfer medium flow path in FIG. 1. [Figure 6] FIG. 2 is a diagram for explaining the 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 the downward flow path and the reformed fuel discharge flow path of FIG. 1. [Figure 9]FIG. 2 is a diagram for explaining the downward flow path of FIG. 1. [Figure 10] 2 is a perspective view of the lower plate of FIG. 1, with a portion cut away, as seen from above; FIG. [Figure 11] 2 is a perspective view of the lower plate of FIG. 1, seen from below, with a portion cut away; FIG. [Figure 12] FIG. 2 is a partially enlarged view of the stirring member and its surroundings in FIG. 1. [Figure 13A] 13A 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] 1. FIG. 1 is a cross-sectional view of the lower plate taken along line XIV-XIV in FIG. [Figure 15] 1B is a cross-sectional view of the upper plate taken along line XV-XV in FIG. 1B. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 15. An agitator according to an embodiment of the present invention generates fine bubbles by agitating a liquid and a gas. In particular, an agitator that agitates a reaction liquid and a gas to generate fine bubbles and supplies the bubbles from below to a reactor in which a gas-liquid reaction occurs 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 fuel supplied to the engine from a fuel tank by an oxidation reaction.

[0009] The Earth's average temperature is maintained at a warm level suitable for living organisms by greenhouse gases in the atmosphere. Specifically, greenhouse gases absorb some of the heat radiated from the Earth's surface, heated by sunlight, into space and then re-radiate it back to the Earth's surface, maintaining a warm atmosphere. An increase in the concentration of greenhouse gases in the atmosphere leads to an increase in the Earth's average temperature (global warming). Carbon dioxide, a greenhouse gas that contributes significantly to global warming, has its atmospheric concentration determined by the balance between carbon fixed on land and in the ground as plants and fossil fuels and carbon present in the atmosphere as carbon dioxide. For example, when carbon dioxide is absorbed from the atmosphere through photosynthesis during plant growth, the concentration of carbon dioxide in the atmosphere decreases. Meanwhile, when carbon dioxide is released into the atmosphere through the combustion of fossil fuels, the concentration of carbon dioxide in the atmosphere increases. To mitigate global warming, it is necessary to reduce carbon emissions by replacing fossil fuels with renewable energy sources such as solar and wind power, and renewable fuels derived from biomass, etc.

[0010] Low-octane gasoline obtained by Fischer-Tropsch (FT) synthesis is becoming increasingly popular as a renewable fuel. Low-octane gasoline has high ignition properties and can be used in compression-ignition engines, but it is still in the early stages of adoption and is not available in some regions. On the other hand, normal-octane gasoline for currently popular spark-ignition engines has low ignition properties and cannot be used in compression-ignition engines as 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 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 agitates liquid and gas to generate bubbles. In the following, an example will be described in particular in which fuel and air are agitated to generate bubbles, and fuel containing the generated bubbles is supplied to the reforming reactor 100. 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 the 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 made of a metal material with 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) and a seal ring (not shown) interposed therebetween. The lower piece 100B of the reforming reactor 100 is formed with a reaction channel 10 through which a fuel flows and a heat medium channel 20 through which a heat medium flows. As shown in FIGS. 1 to 3, the reaction channel 10 and the heat medium channel 20 are configured in a band shape extending in a width direction parallel to a vertical axis C and a length direction perpendicular to the width direction, and are configured in a spiral shape centered on the vertical axis C and 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 illustrating the reaction channel 10. As shown in FIGS. 1 and 4, the height of the upper end surface of the reaction channel 10 is uniform across the entire radial area. Pre-reformed fuel containing finely bubbled air is supplied to the reaction channel 10 from below across the entire radial area by a stirring device 200. The fine bubbles supplied to the reaction channel 10 flow upward along the width direction of the reaction channel 10.

[0014] Hydrocarbon-based fuels can be oxidized and reformed using catalysts such as N-hydroxyphthalimide (NHPI) to generate peroxides, improving their ignition ability. Specifically, NHPI easily abstracts hydrogen atoms with oxygen molecules, generating phthalimide-N-oxyl (PINO) radicals. PINO radicals abstract hydrogen atoms from hydrocarbons (RH) contained in the fuel, generating alkyl radicals (R·). The alkyl radicals combine with oxygen molecules to generate alkylperoxy radicals (ROO·). The alkylperoxy radicals abstract hydrogen atoms from hydrocarbons contained in the fuel, generating alkylhydroperoxides (ROOH), a peroxide. [ka]

[0015] The reaction 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 within the reaction channel 10. The fuel supplied to the reaction channel 10 and the oxygen contained in the air (fine bubbles) come into contact with the catalyst provided within the reaction channel 10. This promotes the oxidation reforming reaction of the fuel throughout the entire radial area of ​​the reaction channel 10.

[0016] As shown in Fig. 2, the gap g1 between the inner wall surfaces of the reaction channel 10, more specifically, between the inner end surface and the outer end surface of the reaction 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 channel 10 is always located within the quenching distance from the reactants, 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 channel 10, which serves as the reaction field where the fuel oxidation reaction progresses, with the maximum safe gap, the safety of the reforming reactor 100 can be further improved because even if a flame enters from an adjacent device, it is immediately extinguished.

[0017] FIG. 5 is a diagram for explaining the heat medium passage 20. As shown in FIGS. 1 and 5, the upper end surface of the heat medium passage 20 is formed so as to incline upward radially inward. A heat medium supply passage 21 is formed in the lower piece 100B of the reforming reactor 100, for supplying a heat medium to the vicinity of the lower end of the outermost diameter portion of the heat medium passage 20. The heat medium supply passage 21 extends so as to incline downward radially inward so as to connect the vicinity of the lower end of the outermost diameter portion of the heat medium passage 20 with the external space. Engine coolant water as a heat medium is supplied to the heat medium passage 20 from an engine (not shown) via 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 portion of the heat medium passage 20 is formed in the lower piece 100B of the reforming reactor 100. The heat medium discharge passage 22 projects 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 within 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 at 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 so that the plurality of communication holes 24 are larger at the bottom and smaller at 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, downward flow paths 30 through which reformed fuel (reformed fuel) flows are formed above the heat transfer path 20. That is, the downward flow paths 30 are also configured in a spiral shape around the vertical axis C, and are arranged alternately with the reaction flow paths 10 in the radial direction.

[0021] 7 and 8 are cross-sectional views for explaining the descending flow channel 30. As shown in FIGS. 1, 7, and 8, the upper end surface of the descending flow channel 30 is open so as to communicate with the upper end surface of the reaction flow channel 10. The heights of the upper end surfaces of the reaction flow channel 10 and the descending flow channel 30 correspond to the height of the partition wall 31 separating the reaction flow channel 10 from the descending flow channel 30 (and the heat transfer medium flow channel 20), and are the same across the entire radial range. The heat transfer medium flow channel 20 and the descending flow channel 30 are separated by a partition wall 32, and the heights of the upper end surface of the heat transfer medium flow channel 20, the lower end surface of the descending flow channel 30, and the partition wall 32 are approximately the same across the entire radial range. The lower end surface of the descending flow channel 30 is located higher than the lower end surfaces of the reaction flow channel 10 and the heat transfer medium flow channel 20 across the entire radial range, and is formed to be inclined downwardly radially outward.

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

[0023] 7 and 8, the gap g2 between the first protrusion 40 and the second protrusion 50, more specifically, the gap g2 between the outer end face of the first protrusion 40 and the inner end face of the second protrusion 50 in the radial direction, is configured to be no more than twice the quenching distance or the maximum safe gap. Similarly, the gap g3 between the outer end face of the second protrusion 50 and the inner end face of the first protrusion 40 is configured to be no more than twice the quenching distance or the maximum safe gap. Furthermore, the gap g4 between the upper end face of the reaction channel 10 and the lower end face of the first protrusion 40, and the gap g5 between the lower end face of the descending channel 30 and the lower end face of the second protrusion 50 are also configured to be no more than twice the quenching distance or 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 channel 10 and the descending channel 30 and the lower end surface of the first protrusion 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 protrusion 40 and the second protrusion 50. As shown in FIG. 1 , the upper piece 100A of the reforming reactor 100 is formed with a gas discharge channel 33 that discharges gas from the reaction channel 10. The gas discharge channel 33 communicates with the reaction channel 10 via the gas-liquid separation space SP1. The air supplied to the reaction channel 10 rises in the reaction channel 10 and is used for the reforming reaction, then released from the gas-liquid separation surface L1 into 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 via the gas discharge 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 downward flow passage 30. As shown in FIG. 1 and FIGS. 7 to 9, the lower end surface of the downward flow passage 30 is formed to be inclined downward radially outward. As shown in FIGS. 1, 2, and 7 to 9, the lower piece 100B of the reforming reactor 100 has a reflux flow passage 60 formed at the lower end of the outermost diameter part of the reaction flow passage 10, for refluxing the reformed fuel. As shown in FIGS. 7 and 8, a gap g6 between the inner wall surfaces of the reflux flow passage 60, more specifically, between the inner end surface and outer end surface of the reflux 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 reflux channel 60 includes a vertical channel 60a, a horizontal channel 60b, and an inclined channel 60c. The vertical channel 60a extends vertically from near the upper end to near the lower end of the lower piece 100B at the outermost diameter portions of the reaction channel 10 and the heat transfer channel 20, i.e., at the outermost diameter side of the outermost diameter portion of the partition wall 31. The horizontal channel 60b extends horizontally at the upper end surface of the outermost diameter portion of the partition wall 31 so as to connect the outermost diameter portion of the descending channel 30 with the upper end surface of the vertical channel 60a. The inclined channel 60c extends radially inward at a downward gradient so as to connect the lower end of the vertical channel 60a with the lower end of the outermost diameter portion of the reaction channel 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 connect the vertical passage 60a to 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, flows over the partition wall 31 into the descending channel 30, and flows radially outward along the length direction of the descending channel 30. When the reformed fuel reaches the outermost diameter portion of the descending channel 30, a portion of the reformed fuel 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] To improve the reforming rate in the reaction 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 channel 10. One known method for supplying a liquid containing fine bubbles is to generate fine bubbles by supplying gas into the liquid through a filter made of a porous material such as a sintered body or a foam. However, with this method, if the filter has uneven pores or gaps, large bubbles are preferentially generated from the larger pores or gaps, making it difficult to generate a sufficient amount of fine bubbles. In particular, as the volume of the filter increases, the influence of uneven pores and gaps becomes greater, making it difficult to generate a sufficient flow of fine bubbles.

[0030] Known methods that do not use a filter include a method of swirling a liquid at high speed and generating fine bubbles through shear caused by the swirling flow, and a method of generating fine bubbles through cavitation by rapidly contracting and expanding a flow path. However, these methods assume that the flow rate of the liquid is relatively large, and are difficult to apply when the flow rate of the liquid is relatively small, such as a fuel flow rate corresponding to the required engine output. Therefore, in this embodiment, the agitation device 200 is configured as follows so that fine bubbles can be efficiently generated by agitation, thereby enabling a fuel (liquid) containing a sufficient amount of fine bubbles to be supplied 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 that is interposed between the lower plate 230 and the reforming reactor 100.

[0032] The stirring member 210 is arranged rotatably 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 the motor 220 by a so-called magnetic coupling, so that it is rotated without contact.

[0033] More specifically, a substantially cylindrical shaft portion 211 having a vertical axis C as its center is fixed to the lower plate 230 by press-fitting or the like so as to be non-rotatable relative to the shaft portion 211. An agitating member 210 is provided on the outer peripheral 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 agitating member 210 so as to be rotatable relative to the shaft portion 211. The lower surface of the agitating member 210 and the upper surface of the spacer 210a are provided with irregularities, thereby fixing the agitating member 210 and the spacer 210a so as to be non-rotatable relative to each other. An inner magnet 212 is fixed to the outer peripheral surface of the spacer 210a so as to be non-rotatable relative to the spacer 210a. The vertical movement of the spacer 210a and the inner magnet 212 is restricted by the lower end of the shaft portion 211. A partition wall portion 230a is provided below the lower plate 230. The partition wall portion 230a forms a storage chamber 213 that houses the shaft portion 211, spacer 210a, and inner magnet 212 below the stirring member 210. The partition wall portion 230a is fixed to, for example, the lower surface of the lower plate 230. The storage chamber 213 communicates with a passage 231 of the lower plate 230. The storage 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 other components 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 surface of the annular portion 238.

[0039] 1, 10, 11, and 12, the cover portion 233 is formed in a generally annular shape in plan view centered on the vertical axis C, and extends radially downward from the outer circumferential surface of the cylindrical portion 237 so as to cover the upper surface of the agitating member 210. The lower surface 233a of the cover portion 233 is formed in a concave shape facing the upper surface of the agitating member 210. The cover portion 233 is formed with a protrusion 233b that protrudes downward from the lower surface 233a toward the upper surface of the agitating 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 inward 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 inward at an upward gradient so as to communicate the passage 231 with the external space. Unreformed fuel is supplied to the passage 231 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] 12, the gas supply flow path 235a communicates with a space (retention space) SP3 between the upper surface of the agitating member 210 and the cover portion 233 via a substantially cylindrical space (cylindrical space) SP2 along the outer circumferential surface of the cylindrical portion 237. Similarly, the liquid supply flow path 234a also communicates with the retention space SP3 via the cylindrical space SP2. As shown in FIGS. 11 and 12, a spiral groove 237a is formed on the outer circumferential surface of the cylindrical portion 237 so that the height of the cylindrical space SP2 spirally decreases from the position where the liquid supply flow path 234a and the gas supply flow path 235a communicate with each other along the rotation direction of the motor 220 (clockwise in the illustrated example). In other words, the uppermost part of the cylindrical space SP2, where the liquid supply flow path 234a and the gas supply flow path 235a communicate with each other, is the starting point or 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 agitating member 210 includes a base portion 214, a guide portion 215, multiple (four in the illustrated example) disk portions 216a-216d, and multiple columnar portions 217. The base portion 214 is formed in a generally plate-like annular shape centered on a vertical axis C, and the agitating 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. Concave and recessed portions are formed on at least a portion of the lower surface of the base portion 214, and the concave and convex portions on the lower surface of the base portion 214 fit into the concave and convex portions on the upper surface of the spacer 210a, thereby fixing the agitating member 210 and the spacer 210a so that they cannot rotate relative to each other and rotate integrally. The guide portion 215 is cylindrically extended upward from the upper surface of the base portion 214 on the outer diameter side of the cylindrical portion 237.

[0043] The disc portions 216a-216d extend horizontally and radially outward from the outer peripheral surface of the guide portion 215. The disc portions 216a-216d are provided in multiple stages (four stages in the illustrated example) in the vertical direction. The diameters of the upper two disc portions 216a and 216b are smaller than the diameters of the lower two disc portions 216c and 216d. The multiple columnar portions 217 protrude upward from the upper surface of the base portion 214 on the outer diameter side of the cylindrical portion 237 so as to connect the multiple stages of disc portions 216a-216d. The columnar portion 217 protrudes upward from the upper surface of the uppermost disc portion 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 disc portion 216a, or at least below the upper surface of the uppermost disc portion 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 FIGS. 13A to 13D, a plurality of openings 218 are provided in each of the disk portions 216a to 216d so as to shear the liquid and the 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 portions 216a, 216c is defined by a plurality of straight lines extending in a first direction (the X-axis direction in the illustrated example) and a plurality of straight lines extending in a second direction (the Y-axis direction in the illustrated example) perpendicular to the first direction. It is also defined by a plurality of straight lines extending in a third direction different from both the first and second directions, 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 and second directions at an angle greater than 0 degrees and less than 90 degrees, for example, 45 degrees, in a plan view. In other words, the plurality of disk portions 216a-216d are arranged such that the phases of the openings 218 of the disk portions 216a, 216b, the disk portions 216b, 216c, and the disk portions 216c, 216d facing each other are shifted.

[0046] The fuel and air supplied to the cylindrical space SP2 via the liquid supply flow path 234a and the gas supply flow path 235a spirally descend along the groove 237a in the rotational direction of the motor 220 and flow into the retention space SP3 above the uppermost disk portion 216a. The fuel and air that flow into the retention space SP3 are drawn in by the cylindrical portion 217 that protrudes upward from the uppermost disk portion 216a of the agitator 210, which rotates in the rotational direction of the motor 220, and the opening 218 of the uppermost disk portion 216a, and are taken into the agitator 210. In this way, by positioning the uppermost disk portion 216a above the liquid level L2 and by having the multiple cylindrical portions 217 protrude upward, the air that has accumulated in the retention space SP3 can be efficiently taken into the agitator 210.

[0047] The fuel and air taken into the agitator 210 flow downward along the outer circumferential surface of the guide portion 215 and then flow radially outward due to the centrifugal force of rotation. While being sheared and agitated by the edges (angular cross sections) of the multiple openings 218, fine bubbles are generated. More specifically, the multiple circular disks 216a-216d are provided with a grid-like pattern of multiple openings 218, and the horizontal cross sections (FIGS. 13A-13D) and vertical cross sections (FIG. 12) of each of the circular disks 216a-216d are formed with multiple angular cross sections. By forming the agitator 210 in this manner with a large number of 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 shape with a large number of round cross sections formed by bending wire, for example, thereby reducing agitation resistance and energy consumption. Furthermore, excessive flow rates of the fuel and air supplied to the reforming reactor 100 can be prevented. 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, which allows fine bubbles to be generated more efficiently.

[0048] 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-channel forming portion 236 forms a plurality of annular flow channels 236a on concentric circles centered on the vertical axis C, from the outer peripheral surface of the cylindrical portion 237 to the inner peripheral 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-channel forming portion 236 includes a plurality of radial portions 236b extending radially from the outer peripheral surface of the cylindrical portion 237 to the inner peripheral surface of the annular portion 238, and a plurality of annular portions 236c provided on concentric circles centered on the vertical axis C. The plurality of annular portions 236c are connected to each other via the radial portions 236b and to the outer peripheral surface of the cylindrical portion 237 and the inner peripheral 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 circumferential surface and the outer circumferential 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 agitating member 210 flows radially outward due to the centrifugal force of the rotation and is emitted radially outward from below the cover portion 233. The fuel containing fine bubbles emitted radially outward from below the cover portion 233 flows along the conical surface 232a to the outermost diameter portion due to the centrifugal force of the rotation, and then 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. Furthermore, the turbulence generated by agitation by the agitating 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 channel 240a that is spirally shaped and centered on the vertical axis C, corresponding to the reaction channel 10 of the reforming reactor 100. As shown in FIGS. 1, 14 and 15, fuel containing fine bubbles that flows out from the upper end of the annular channel 236a is collected and flows into the spiral channel 240a of the upper plate 240. The fuel containing fine bubbles that flows into the spiral channel 240a flows upward along the spiral channel 240a and is further straightened, thereby further attenuating turbulence caused by stirring by the stirring member 210, before flowing into the reaction channel 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 of the spiral channel 240a.

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

[0053] When fine bubbles are generated using the agitator 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 adjusting them to the fuel flow rate required on the reforming reactor 100 side. For example, the shape of the agitator 210, the rotation speed of the motor 220, the air supply flow rate, etc. can be changed as needed.

[0054] According to this embodiment, the following effects can be achieved. (1) The agitator 200 includes an agitator 210 having substantially plate-shaped disk portions 216a-216d rotatably disposed about a vertical axis C within a passage 231 through which a liquid and a 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 the gas (FIGS. 13A-13D). The ends of the disk portions 216a-216d and the ends of the plurality of openings 218 that come into contact with the liquid shear the liquid and the 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 sides 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 (FIG. 12, FIGS. 13A to 13D). In this case, the ends of each opening 218, i.e., the multiple sides of the lattice (four sides on each side 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, thereby more efficiently shearing the liquid and gas and more efficiently generating fine bubbles.

[0058] (5) The agitating 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 gas (FIGS. 1 and 12). This allows the liquid and gas to be sheared more efficiently, thereby enabling fine bubbles to be generated more efficiently.

[0059] (6) The agitating 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 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 portions 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 turbulence between the opposing disk portions 216a, 216c and between the openings 218 of the disk portions 216a, 216c, thereby enabling fine bubbles to be generated more efficiently.

[0060] (7) The agitator 210 has multiple stages of disc portions 216a to 216d in the vertical direction (FIGS. 1 and 12). Of the multiple stages of disc portions 216a to 216d, the diameter of the topmost disc portion 216a is smaller than the diameter of the bottommost disc portion 216d (FIGS. 13A and 13D). This allows the topmost disc portion 216a to efficiently take in gas remaining in the upper passage 231, more efficiently shearing the liquid and gas, and more efficiently generating fine bubbles.

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

[0062] As shown in FIG. 12, the passage 231 cover The gas remaining on the lower surface 233a of the case 233 is taken into the agitator 210 from the upper surfaces of the disk portions 216a to 216d. The liquid and gas taken into the agitator 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 agitator 210 are released radially outward from the cover portion 233 by the centrifugal force of the rotation of the agitator 210. The fine bubbles released radially outward from the cover portion 233 flow radially outward along the conical surface 232a of the case 232 by the centrifugal force, and also 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 agitator 200 is applied to the reforming reactor 100 has been described, but the agitator may be any agitator that can agitate liquid and gas to generate fine bubbles, and is not limited to the example shown.

[0064] The above description is merely an example, and the present invention is not limited to the above-described embodiment and modifications as long as the features of the present invention are not impaired. One or more of the above-described embodiment and modifications can be arbitrarily combined, and modifications can also 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 downflow 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 accommodation 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 path forming portion, 235 gas supply flow path forming portion, 236 annular flow path forming portion, 236a annular flow path, 236b radial portion, 236c annular portion, 237 cylindrical portion, 238 annular portion, 240 upper plate, 240a spiral flow path, C vertical axis, g1 to g12 gaps, L1 liquid level (gas-liquid separation surface), L2 liquid level, 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 disk has a plurality of openings formed therein to shear the liquid and the gas; a case portion that forms a conical surface around the vertical axis, the case portion facing the passage and extending radially outward with an upward gradient about the vertical axis, around the stirring member; a cover portion that covers an upper surface of the disk and has a lower surface that is formed in a concave shape facing the upper surface and has a generally annular shape in a plan view centered on the vertical axis; an annular flow path forming portion that forms a plurality of annular flow paths on concentric circles centered on the vertical axis, above the case portion and radially outward of the cover portion centered on the vertical axis; a supply flow path forming portion that forms a supply flow path that supplies the liquid and the gas to the passage between the disk and the cover portion.

2. The stirring device according to claim 1, The stirring device is characterized in that the plurality of openings are arranged in a lattice pattern.

3. The stirring device according to claim 2, The plurality of openings are formed so that the horizontal and vertical cross 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 agitator is characterized in that the disk has a protruding portion that protrudes 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, The agitation device is 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 circular plate is provided with a plurality of openings in a lattice pattern 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 pattern 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. 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, The agitator is characterized in that the diameter of the uppermost disc among the plurality of disc stages is smaller than the diameter of the lowermost disc.

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