Provided is an ultrafine bubble generating method and an ultrafine bubble generating apparatus capable of efficiently generating a UFB-containing liquid with high purity. To this end, a flow passage inner volume is varied by using a flow passage inner volume varying element, the liquid is pressurized such that the liquid passes through a narrow portion at high speed and flows into a depressurizing area.

An apparatus for producing nano-bubbles in a moving liquid carrier includes a conduit through which a liquid carrier can flow, a gas diffuser disposed on an inner surface of the conduit, and a funnel comprising: (i) a first open end having a first cross-sectional area that receives a moving liquid carrier; (ii) a second open end opposite the first open end defining a second cross-sectional area smaller than the first cross-sectional area and fluidly coupled to the opening of the conduit; and (iii) a wall extending from the first open end to the second open end. The funnel is configured to create turbulent flow above the turbulent threshold in the absence of external energy that allows the liquid carrier to shear gas from the outer surface of the diffuser, thereby forming nano-bubbles in the liquid carrier.

A filter element for filtering milk in a milk frother, comprising a plate-shaped porous main body, having a first side at which the milk can enter the porous main body, a second side at which the milk can exit from the porous main body, and a lateral side connecting the first and second sides, wherein the surface of the first side is less rough than the surface of the second side, and wherein the first side and the second side are different from one another.

A hydrogen gas dissolving apparatus 1 has a hydrogen supply unit 2 capable of supplying hydrogen gas, and a hydrogen gas dissolution module 6 for bringing the hydrogen gas supplied from the hydrogen supply unit 2 in contact with and dissolved in water. The hydrogen gas dissolution module 6 has a supply port 62 to which the hydrogen gas is supplied, a hydrogen chamber 63 communicating with the supply port 62 and filled with the hydrogen gas supplied from the supply port 62, and an exhaust port 64 communicating with the hydrogen chamber 63 and discharging the air in the hydrogen chamber 63. The exhaust port 64 is located in a lower part of the hydrogen chamber 63.

A gas injection system for injecting a gas into a liquid to form a solution includes a flow channel that conveys a liquid from an upstream inlet configured to receive the liquid and a downstream outlet configured to dispense the solution, sparger positioned in the flow channel, a solution pressure detection device configured to sense a pressure of the solution in the flow channel, and a liquid valve configured to regulate flow of the liquid in the flow channel based on the pressure sensed by the solution pressure detection device. The sparger is configured to inject the gas into the liquid through the porous surface as the liquid flows across the surface.

The device for adjusting the concentration of a gas in a liquid includes a cartridge in which the concentration of the gas in the liquid is adjusted, a pipe for supplying the liquid into the cartridge, a pipe for supplying gas into the cartridge, and a pipe for discharging the liquid from the cartridge. The gas supply pipe includes an expansion valve with of which the pressure setpoint that is controlled by a setpoint for the quantity amount of gas in the liquid and by an amount of a quantity of gas in the liquid measured by a gas concentration sensor located in the liquid discharge pipe.

A gas injection system for injecting a gas into a liquid to form a solution includes a flow channel that conveys a liquid from an upstream inlet configured to receive the liquid and a downstream outlet configured to dispense the solution, sparger positioned in the flow channel, a solution pressure detection device configured to sense a pressure of the solution in the flow channel, and a liquid valve configured to regulate flow of the liquid in the flow channel based on the pressure sensed by the solution pressure detection device. The sparger is configured to inject the gas into the liquid through the porous surface as the liquid flows across the surface.

There is described a cross-flow apparatus for producing an emulsion or dispersion by dispersing a first phase in a second phase; said cross-flow apparatus comprising: an outer tubular sleeve (2) provided with a first inlet (3) at a first end (4); an emulsion outlet (5); and a second inlet (7), distal from and inclined relative to the first inlet; a tubular membrane provided with a plurality of pores and adapted to be positioned inside the tubular sleeve (2); and optionally an insert adapted to be located inside the tubular membrane, said insert comprising an inlet end and an outlet end, each of the inlet end and an outlet end being provided with chamfered region; the chamfered region is provided with a plurality of orifices and a furcation plate.

A functional water producing apparatus in an embodiment includes: a water pressure regulator configured to regulate the water pressure of the ultrapure water, the water pressure regulator having a pressure regulating valve configured to regulate a water pressure of the ultrapure water to an almost constant pressure and a feed water pump configured to pressurize the ultrapure water; a dissolving device configured to dissolve functional gas imparting a specific function in the ultrapure water regulated the water pressure by the water pressure regulator; and a control device configured to control the feed water pump to regulate the water pressure of the functional water to a predetermined constant pressure based on a water pressure or a flow rate of the functional water flowing out of the dissolving device.

A device and method of using the device for high throughput production of emulsions having low coefficient of variation droplet/particle sizes.