An apparatus for treating fluids having improved aeration efficiency and operational durability has an aerator, an impeller, and a liquid reservoir containing liquid to be treated. The aerator has: a motor rotating the impeller at a blade tip speed less than 1,100 inches/second; an air line having an outlet submerged in the liquid and an inlet adjacent to the motor; and a blower. The blower forces air through the air line to the air line outlet. The impeller two blades extending radially from the hub. Each blade has: a low drag, pressure equalized foil shape absent of rake; a leading edge extending from the hub tangentially; a 0.47-0.55 impeller EAR; 0.59-0.87 Pmean/D; progressive pitch distribution based on radius where from 50% R and out is constant and from 50% R to the hub is reduced; and 60-75 degree skew with a linear distribution from 50% radius to blade tip.

Provided is a nano-micro bubble generator according to one aspect of the present invention, the nano-micro bubble generator including: a housing which a fluid flows into and out of; a plurality of rotors rotatably coupled to the inside of the housing; and a plurality of stators fixed to the inside of the housing and alternately arranged with the plurality of rotors, wherein at least one of the rotors and the stators has a mesh-like structure in which a plurality of flow passages of the fluid are arranged in a lattice form, and the rotors and the stators are arranged to be adjacent to each other so as to generate a collision, friction, and cavitation due to rotation of the rotors in the fluid flowing through the flow passages, thereby generating at least one of nano bubbles and micro bubbles in the fluid.

Provided is a nano-micro bubble generator according to one aspect of the present invention, the nano-micro bubble generator including: a housing which a fluid flows into and out of; a plurality of rotors rotatably coupled to the inside of the housing; and a plurality of stators fixed to the inside of the housing and alternately arranged with the plurality of rotors, wherein at least one of the rotors and the stators has a mesh-like structure in which a plurality of flow passages of the fluid are arranged in a lattice form, and the rotors and the stators are arranged to be adjacent to each other so as to generate a collision, friction, and cavitation due to rotation of the rotors in the fluid flowing through the flow passages, thereby generating at least one of nano bubbles and micro bubbles in the fluid.

Provided is a gas-dissolved water generating apparatus in which a pressure pump and a multi-stage mixer are sequentially arranged on at least one conduit; a circulation pipe connecting an inlet side of the pressure pump and a outlet side of the pressure pump is positioned on the conduit; a gas supply unit for supplying a predetermined external gas to one side of the circulation pipe, which is connected to the inlet side of the pressure pump, via a gas supply pipe; the gas supply unit and the circulation pipe are connected through a three-way valve, and the three-way valve is configured to have a structure of a venturi pipe having wide inlet and outlet channels and a narrow interior channel along the circulation pipe, so that a gas supplied from the gas supply unit is independently sucked.

An artificial-whirlpool generator includes a whirlpool generating member including at least one water inlet, a whirlpool generating chamber communicating with the water inlet, and a whirlpool outlet that is formed at a lower end portion of the whirlpool generating member and communicates with the whirlpool generating chamber; a position-fixing means that fixes the whirlpool forming member such that the entirety of the whirlpool generating member or only a portion of the whirlpool generating member, including the whirlpool outlet is submerged; and a swirling flow forming unit that forces water in a waterbody to be introduced into the whirlpool generating chamber through the water inlet and rotates the introduced water in one direction around an axle provided at a center portion of the whirlpool generating chamber to form a whirlpool that descends toward the whirlpool outlet.

Fermenter for producing a shear-thinning medium comprising a tank volume and a stirring arrangement having an improved distribution capacity or a more uniform shear stress.

Disclosed is a reactor for treating, particularly by hydrothermal carbonization, sludge containing organic matter, including, with: a vessel (100) including an inner chamber arranged to receive the sludge and to form a path of travel for the sludge adapted to allow for circulation of the sludge, a sludge inlet (1) arranged to introduce the sludge into a sludge introduction area of the inner chamber, a sludge outlet (11) arranged to discharge at least part of the sludge contained in the inner chamber, and a steam inlet (3) arranged to inject steam in a steam injection zone of the inner chamber along a steam injection direction, the steam injection direction being different from a sludge circulation direction in the steam injection zone along the circulation path, the steam injection zone being separated from the sludge introduction zone.

A system for evolving and dissolving a gas with a liquid can include a vessel having at least one wall forming a cavity, where the at least one wall includes at least one first surface feature disposed on an inner surface of the at least one wall. The liquid and the gas can be disposed within the cavity. The at least one first surface feature can alter the rate at which the gas evolves from or dissolves into the liquid.

A system for evolving and dissolving a gas with a liquid can include a pressure vessel in which a liquid mixed with a gas is disposed, and a gas source coupled to the pressure vessel. The system can also include at least one regulating device that regulates a parameter within the pressure vessel. The system can further include at least one sensor that measures at least one parameter as a function of time, where the at least one parameter is associated with the gas within the pressure vessel. The system can also include a controller that controls the regulating device based on measurements of the at least one parameter taken by the at least one sensor, to evolve and dissolve the gas within the pressure vessel.

An artificial-whirlpool generator includes a whirlpool generating member including at least one water inlet, a whirlpool generating chamber communicating with the water inlet, and a whirlpool outlet that is formed at a lower end portion of the whirlpool generating member and communicates with the whirlpool generating chamber; a position-fixing means that fixes the whirlpool forming member such that the entirety of the whirlpool generating member or only a portion of the whirlpool generating member, including the whirlpool outlet is submerged; and a swirling flow forming unit that forces water in a waterbody to be introduced into the whirlpool generating chamber through the water inlet and rotates the introduced water in one direction around an axle provided at a center portion of the whirlpool generating chamber to form a whirlpool that descends toward the whirlpool outlet.