A device for generating bubbles, comprising a porous material having at least one hydrophilic surface (1), arranged such that a liquid (7) in which the bubbles (6) are intended to be formed may contact the hydrophilic surface (1) and at least one hydrophobic surface (2), arranged such that a gas (5) used to generate the bubbles (6) may flow past the hydrophobic surface (2) before it flows past the hydrophilic surface (1). The device may be used for creating fine bubbles in numerous applications, such as wastewater treatment, plant cultivation, aquafarming, aeration systems, bioreactors, fermeters, oil extraction or fuel cells.

Disclosed is a hydrogen recirculation ejector for fuel cells including a recirculation line configured to recirculate residual hydrogen gas discharged from a fuel cell stack configured to generate electricity using air and hydrogen gas supplied thereto to an inlet of the fuel cell stack and an ejector including a nozzle installed on the recirculation line, the nozzle being configured to supply new hydrogen gas, a venturi tube configured to mix the hydrogen supplied from the nozzle and the recirculated hydrogen with each other, and a diffuser configured to supply the mixed hydrogen gas to the fuel cell stack, wherein the nozzle includes a hydrogen introduction portion, a ring-shaped inner wall, a ring-shaped outer wall, a ring-shaped front end wall, and a ring-shaped rear end wall, and wherein the thickness of the inner wall and/or the outer wall is gradually increased with increasing distance from the hydrogen introduction portion.

Provided is a slurry manufacturing method in which a decrease in slurry quality, an increase in running cost, and a decrease in maintainability are suppressed. A slurry manufacturing device includes: a mixing device (suction pump mechanism portion) that mixes a liquid and a powder to manufacture a slurry; a powder supply device that supplies the powder to the mixing device; and a powder dry box, in which an opening portion of the powder supply device is accommodated in the powder dry box.

A flow distribution system for distributing and dividing the flows of at least two separate fluids, the distribution system comprising: a three-dimensional nested structure of at least two fluid transporting fractals comprising at least a first fluid transporting fractal and a second fluid transporting fractal, each fluid transporting fractal having a respective fluid inlet which bifurcates to a plurality of fluid outlets, each fluid transporting fractal being configured to facilitate a flow therethrough independent from a flow in the other fluid transporting fractal, each fluid transporting fractal extending along and about a central axis between fluid inlet and a plurality of fluid outlets; wherein each fluid transporting fractals comprises of a series of recursive bifurcation units assembled in a selected number of stages, each bifurcation unit comprising a Y-shaped bifurcated element which is fluidly connected to two successive bifurcation units, each successive bifurcation unit being rotated relative to the central axis by an angle of between 60 and 120 degrees relative to the previous stage; each fluid transporting fractal is intertwined with the other fluid transporting fractal; each fluid transporting fractal is positioned offset from the other fluid transporting fractal about the central axis and are arranged such that each fluid outlet from one of the fluid transporting fractals is located adjoining a fluid outlet of the other fluid transporting fractal, and each fluid transporting fractal is centered about a flow axis which is laterally inclined from greater than 0 to 20 degrees from the central axis and longitudinally inclined from greater than 0 to 20 degrees from the central axis.

Provided are an apparatus and a method for reaction for use in a co-precipitation reaction for preparing a catalyst or a cathode active material for a lithium secondary battery, which injects a raw material (a solution) at least between impellers according to the solution level in a vessel, thereby making a stirring speed uniform and, in particular, minimizing a concentration difference between solutions. The apparatus for the reaction may comprise: a reaction vessel; a stirring means provided inside the reaction vessel and having multistage impellers; and a raw material injecting means, comprising at least one injection nozzle connected to the reaction vessel, for injecting a raw material at least between impellers.

The invention relates to a feed unit (1) for a fuel cell system (31) for feeding and/or controlling a gaseous medium, in particular hydrogen, comprising a jet pump (4), which is driven by a propelling jet of a gaseous medium under pressure, an outlet of the feed unit being fluidically connected to an anode inlet (5) of a fuel cell (32). The jet pump (4) has an intake region (7), a mixing tube (9) and a diffuser region (11), and the gaseous medium flows through the jet pump in a flow direction (III) which runs parallel to a longitudinal axis (52) of the jet pump (4), and the diffuser region (11) is at least indirectly fluidically connected to the anode inlet (5) of a fuel cell (32). The jet pump (4) has a housing assembly (6), the housing assembly (6) having the components main body (8) and mixing tube insert (17), resulting in particular in a modular design of the jet pump (4).

An apparatus and method for manufacturing an electricity storage material are provided which allow easily measuring the dissolution rate to solubility of a solution of a powder thickener dissolved in a liquid solvent. An apparatus for manufacturing an electricity storage material includes: a dissolving device that dissolves in a liquid solvent a thickener as powder that is ionized when dissolved; and a dissolution-rate-to-solubility determining device that measures conductivity of the solution produced by the dissolving device and determines a dissolution rate to solubility of the solution based on the measured conductivity. The dissolution rate to solubility can thus be determined without the need to stop the dissolving device during dissolution of the thickener in the liquid solvent. This can significantly improve production efficiency. Since excessive operation of the dissolving device can be prevented, energy saving can be achieved.

A flow distribution system for distributing and dividing the flows of at least two separate fluids, the distribution system comprising: a three-dimensional nested structure of at least two fluid transporting fractals comprising at least a first fluid transporting fractal and a second fluid transporting fractal, each fluid transporting fractal having a respective fluid inlet which bifurcates to a plurality of fluid outlets, each fluid transporting fractal being configured to facilitate a flow therethrough independent from a flow in the other fluid transporting fractal, each fluid transporting fractal extending along and about a central axis between fluid inlet and a plurality of fluid outlets; wherein each fluid transporting fractals comprises of a series of recursive bifurcation units assembled in a selected number of stages, each bifurcation unit comprising a Y-shaped bifurcated element which is fluidly connected to two successive bifurcation units, each successive bifurcation unit being rotated relative to the central axis by an angle of between 60 and 120 degrees relative to the previous stage; each fluid transporting fractal is intertwined with the other fluid transporting fractal; each fluid transporting fractal is positioned offset from the other fluid transporting fractal about the central axis and are arranged such that each fluid outlet from one of the fluid transporting fractals is located adjoining a fluid outlet of the other fluid transporting fractal, and each fluid transporting fractal is centered about a flow axis which is laterally inclined from greater than 0 to 20 degrees from the central axis and longitudinally inclined from greater than 0 to 20 degrees from the central axis.

A fuel cell system includes a fuel cell stack, a mixed gas supply passage, and an agitation mixer. The fuel cell stack includes a plurality of fuel cells each including a power generation portion. The fuel cells are stacked. The mixed gas supply passage is configured to communicate with the fuel cell stack. The mixed gas supply passage is configured to supply a mixed gas to the fuel cell stack. The mixed gas is a mixture of a fuel gas and a fuel off-gas that has been discharged from the fuel cell stack. The agitation mixer is provided in the mixed gas supply passage. The agitation mixer is configured to apply a swirling force to the mixed gas. The agitation mixer includes a guide rib configured to guide liquid water contained in the mixed gas to a side opposite to the power generation portion-side.

A battery may include a first electrode, a second electrode, an electrolyte, and at least one acoustic device configured to generate acoustic streaming during a charging and/or a discharging of the battery. The charging of the battery may trigger cations from the first electrode to travel through the electrolyte and deposit on the second electrode while the discharging of the battery may trigger cations from the second electrode to travel through the electrolyte and deposit on the first electrode. The acoustic streaming may drive a mixing and/or a turbulent flow of the electrolyte, which may increase a charge rate and/or a discharge rate of the battery by increasing diffusion rate of cations and/or anions. The mixing and/or the turbulent flow may further prevent a formation of dendrites on the first electrode and/or the second electrode by at least homogenizing a distribution of the cations and/or anions in the electrolyte.