A stirring device of thin-film rotation type includes a tubular portion whose lateral surface has: a band-shaped first region extending circumferentially of the tubular portion and including holes penetrating in a inward-outward direction; and a band-shaped second region extending circumferentially of the tubular portion and including no hole or holes penetrating in the inward-outward direction, where the second region has a smaller aperture ratio than the first region. The first region is located to include a middle of the tubular portion in a height direction The second region ranges from the upper edge of the first region to the upper end of the tubular portion and also from the lower edge of the first region to the lower end of the tubular portion. The first region has a width Wp, and the tubular portion has a height H, where 0<Wp<0.5H.

An impeller assembly for a solid-liquid mixing device, and a solid-liquid mixing device using the impeller assembly. The impeller assembly comprises an impeller. The impeller comprises a truncated conical body. Multiple mixing blades are formed from top to bottom on an inclined surface of the body. The impeller assembly further comprises at least one blocking plate provided on an outer side of a lower portion of the body. The mixing device further comprises: a housing; at least one solid supply apparatus; at least one liquid supply apparatus; a mixing chamber defined by corresponding portions of the body and the housing; and a dispersion chamber provided between a flow channel outlet at a lower portion of the mixing chamber and a discharging apparatus.

A system for preparing a polymeric mixture includes: a containment device configured to distribute dry polymeric materials; a receiving chamber in fluid communication with the containment device; a wetting bowl; a dispersing channel; and a mixing chamber connected to the dispersing channel. A method of preparing a polymeric mixture includes distributing water and dry polymeric materials through the various components of the system and mixing the materials with the mechanical mixing device.

The present invention is in the field of stirring, and particularly relates to a stirring assembly including a rotary shaft and a stirring member. The stirring member is fixedly provided on the rotary shaft. The rotary shaft is provided with a first passage therein. The first passage is formed with an air inlet through one end of the rotary shaft. The stirring member is provided with a second passage therein. The second passage is formed with an air outlet through the stirring member. The second passage is connected with the first passage. In the present invention, when the rotary shaft is rotating, the external air is drawn in from the air inlet and discharged from the air outlet to make the liquid to be mixed by the stirring member with the air discharged from the air outlet.

A fluid treatment system (1), such as a turbo emulsifier, comprises a tank (2) for containing a static fluid mass. A rotation shaft (3) is rotated by a motor (4). A cavitating impeller (5) is mounted to the rotation shaft (3), inside a compartment (21) of the tank (2), so as to be immersed in the fluid mass. The impeller (5) has a pair of walls (51), a gap (53) delimited by inner faces (54) of the walls (51), and blades (56) arranged in the gap (53).

A wastewater purification apparatus includes an elongate tank, which has an inflow for feeding wastewater, a first vertical agitator with a first hyperboloid agitator body mounted on a vertical first agitator shaft and provided in a first treatment portion downstream of the inflow on the first narrow side, a second vertical agitator with a second hyperboloid agitator body mounted on a vertical second agitator shaft and provided in a second treatment portion downstream of the first vertical agitator, an aeration device with a fan for aerating wastewater received in the tank, a first drive device for rotating the first hyperboloid agitator body in a first rotation direction, a second drive device for rotating the second hyperboloid agitator body in a second rotation direction opposite the first rotation direction, and a decanter for discharging purified wastewater in a third treatment portion on a second narrow side opposite the first narrow side.

A wastewater purification apparatus includes an elongate tank, which has an inflow for feeding wastewater, a first vertical agitator with a first hyperboloid agitator body mounted on a vertical first agitator shaft and provided in a first treatment portion downstream of the inflow on the first narrow side, a second vertical agitator with a second hyperboloid agitator body mounted on a vertical second agitator shaft and provided in a second treatment portion downstream of the first vertical agitator, an aeration device with a fan for aerating wastewater received in the tank, a first drive device for rotating the first hyperboloid agitator body in a first rotation direction, a second drive device for rotating the second hyperboloid agitator body in a second rotation direction opposite the first rotation direction, and a decanter for discharging purified wastewater in a third treatment portion on a second narrow side opposite the first narrow side.