US 12,472,477 B2
Control of a flow generator in a tank
Peter Loman, Järfälla (SE); Ulf Carlsson, Täby (SE); and Andrew Nicholas Dames, Cambridgeshire (GB)
Assigned to Xylem Europe GmbH, Schaffhausen (CH)
Appl. No. 17/924,046
Filed by Xylem Europe GmbH, Schaffhausen (CH)
PCT Filed May 19, 2021, PCT No. PCT/EP2021/063244
§ 371(c)(1), (2) Date Nov. 8, 2022,
PCT Pub. No. WO2021/233972, PCT Pub. Date Nov. 25, 2021.
Claims priority of application No. 20175616 (EP), filed on May 20, 2020.
Prior Publication US 2023/0182095 A1, Jun. 15, 2023
Int. Cl. B01F 35/221 (2022.01); B01F 27/113 (2022.01); B01F 27/71 (2022.01); B01F 35/21 (2022.01); B01F 35/32 (2022.01); B01F 35/33 (2022.01); E03F 5/26 (2006.01); B01F 101/00 (2022.01)
CPC B01F 35/221422 (2022.01) [B01F 27/113 (2022.01); B01F 27/71 (2022.01); B01F 35/2113 (2022.01); B01F 35/3204 (2022.01); B01F 35/33 (2022.01); E03F 5/26 (2013.01); B01F 2101/305 (2022.01); B01F 2215/0409 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method for controlling a flow generator in a tank configured for housing a liquid comprising solid matter, the flow generator comprising an impeller located at a height (h-mixer) in the tank and the tank having a predetermined maximum filling height (h-max), the method comprising:
operating the flow generator at a variable operational speed (n) with a demand of operational speed (n-demand) dependent on a present liquid level height (h-present) in the tank,
wherein a max operational speed (n-max) of the flow generator is an operational speed required when a liquid level in the tank is equal to the maximum filling height (h-max), and a present operational speed (n-present) is set equal to a demand of operational speed (n-demand) of the flow generator determined using the formula:

OG Complex Work Unit Math
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 meters.