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.

A stirrer device, especially for the mixing of a fluid with at least one other fluid, includes at least one fluid dispersing unit able to turn about an axis of rotation, having at least one exit opening for at least one fluid discharge, and the stirrer device has at least one optimization unit, which in at least one operating state increases at least a differential pressure at the exit opening.

A stirrer device, especially for the mixing of a fluid with at least one other fluid, includes at least one fluid dispersing unit able to turn about an axis of rotation, having at least one exit opening for at least one fluid discharge, and the stirrer device has at least one optimization unit, which in at least one operating state increases at least a differential pressure at the exit opening.

A vane for an impeller of an agitator includes a socket having a base plane configured to mount the vane to an impeller, and a blade configured to mix a process fluid, the blade having a leading edge, a trailing edge, and a blade tip extending from the leading edge to the trailing edge at an end of the blade facing away from the socket, the blade having a pressure side and a suction side, and the pressure side having a first concave region towards the leading edge, a second concave region toward the trailing edge and a convex region between the first and second concave regions.

A vane for an impeller of an agitator includes a socket having a base plane configured to mount the vane to an impeller, and a blade configured to mix a process fluid, the blade having a leading edge, a trailing edge, and a blade tip extending from the leading edge to the trailing edge at an end of the blade facing away from the socket, the blade having a pressure side and a suction side, and the pressure side having a first concave region towards the leading edge, a second concave region toward the trailing edge and a convex region between the first and second concave regions.

A rotary injector comprising an elongated shaft having a proximal end and a distal end, and an impeller at the distal end of the elongated shaft, the elongated shaft and the impeller being collectively rotatable during operation around an axis of the shaft, the rotary injector being hollow and having an internal supply conduit extending along the shaft and across the impeller, the supply conduit having an inlet at the proximal end of the shaft, a main portion extending from the inlet to a discharge portion, the discharge portion extending to an axial outlet, the discharge portion having a narrow end connecting the main portion of the supply conduit and a broader end at the axial outlet.

The invention relates to a method for controlling a flow generator (1) in a tank (20) configured for housing a liquid comprising solid matter, the flow generator (1) comprising an impeller and being located at a height (h-mixer) in the tank (20) and the tank (20) having a predetermined maximum filling height (h-max), wherein the flow generator (1) is configured to be operated at a variable operational speed (n) and the demand of operational speed (n-demand) is dependent on the present liquid level height (h-present) in the tank (20), wherein a max operational speed (n-max) of the flow generator (1) is the operational speed required when the liquid level in the tank (20) is equal to the maximum filling height (h-max), the present operational speed (n-present) being set equal to the demand of operational speed (n-demand) of the flow generator (1) that is determined using the formula:

[00001]$\left(n-\mathrm{present}\right)=\left(n-\mathrm{demand}\right)=\frac{\left(n-\max \right)}{\left[\left(h-\max \right)/\left(h-\mathrm{present}\right)\right]^a}$

at least when [(h-mixer)+X]≤(h-present)≤(h-max), wherein a≥(¼) and a<1, X=radius of the impeller of the flow generator+1, and all heights and measures are given in meter.

The invention relates to a method for controlling a flow generator (1) in a tank (20) configured for housing a liquid comprising solid matter, the flow generator (1) comprising an impeller and being located at a height (h-mixer) in the tank (20) and the tank (20) having a predetermined maximum filling height (h-max), wherein the flow generator (1) is configured to be operated at a variable operational speed (n) and the demand of operational speed (n-demand) is dependent on the present liquid level height (h-present) in the tank (20), wherein a max operational speed (n-max) of the flow generator (1) is the operational speed required when the liquid level in the tank (20) is equal to the maximum filling height (h-max), the present operational speed (n-present) being set equal to the demand of operational speed (n-demand) of the flow generator (1) that is determined using the formula:

[00001]$\left(n-\mathrm{present}\right)=\left(n-\mathrm{demand}\right)=\frac{\left(n-\max \right)}{\left[\left(h-\max \right)/\left(h-\mathrm{present}\right)\right]^a}$

at least when [(h-mixer)+X]≤(h-present)≤(h-max), wherein a≥(¼) and a<1, X=radius of the impeller of the flow generator+1, and all heights and measures are given in meter.

Agitating device (10) for a digester (1) of a biogas plant (100) having a housing (11) and a driving device (12) for rotatably driving the agitator blades (13-15). The driving device (12) comprises a drive shaft (16) and an electric drive motor (20) wherein the drive motor (20) is accommodated sealed in the housing (11). The drive motor (20) comprises an outer, hollow stator (21) and a rotary rotor (22) which is centrally accommodated therein and is configured at least partially hollow. The rotor (22) is rotatably supported at the housing (11) and comprises a coupling device (23) for non-rotatable coupling with the drive shaft (16) to drive the at least one agitator blade (13-15) by means of the drive shaft (16).

A bioprocess vessel includes a flexible bag or substantially rigid container that defines an interior volume and having a bottom surface, the bottom surface being open or containing an aperture therein for the passage of fluid. A pump is secured to the bottom surface of the flexible bag or substantially rigid container. In some embodiments is secured directly to the flexible bag or substantially rigid container. In other embodiments, the pump is secured indirectly the flexible bag or substantially rigid container using, for example, a port that extends through the aperture on the bottom surface. The port or flanged surface may also be integrated into the pump, which is secured to the vessel. An optional mixing adaptor may be provided inside the interior volume of the flexible bag or substantially rigid container and at least partially covers the inlet that leads to the pump.