A sewage system component spray assembly is attached at a predetermined height above pumps in the interior of the component and has at least one nozzle for spraying liquid downwardly and generally tangential to a center of the sewage system component. Operation of the nozzle causes the liquid to disperse floating material on the sewage surface and creating a rotational flow around the center to direct such material to the pumps. The source of the sprayed liquid may be internal to the sewage system component.

A sewage system component spray assembly is attached at a predetermined height above pumps in the interior of the component and has at least one nozzle for spraying liquid downwardly and generally tangential to a center of the sewage system component. Operation of the nozzle causes the liquid to disperse floating material on the sewage surface and creating a rotational flow around the center to direct such material to the pumps. The source of the sprayed liquid may be internal to the sewage system component.

A dispenser system includes at least one main tubular element, at least one nozzle, and openings formed on the main tubular element. The at least one nozzle receives and injects a first fluid inside the main tubular element. The openings in conjunction with the nozzle (20) enable fluid circulation between inside and outside of the main tubular element.

A dispenser system includes at least one main tubular element, at least one nozzle, and openings formed on the main tubular element. The at least one nozzle receives and injects a first fluid inside the main tubular element. The openings in conjunction with the nozzle (20) enable fluid circulation between inside and outside of the main tubular element.

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.

A casing liner used for a sewage pump includes a surface to face an edge of a blade of an impeller when the casing liner is assembled with the impeller into the sewage pump. At least one groove with given width is formed in at least a part of the surface. The groove includes a first section with given depth, which is located on the side close to a rotational center of the impeller, a second section smaller in depth than the first section, which is located on the side far from the rotational center of the impeller, and a third section that is an inclined face connecting the first and second sections, the first to third sections being arranged in a width direction of the groove.

A casing liner used for a sewage pump includes a surface to face an edge of a blade of an impeller when the casing liner is assembled with the impeller into the sewage pump. At least one groove with given width is formed in at least a part of the surface. The groove includes a first section with given depth, which is located on the side close to a rotational center of the impeller, a second section smaller in depth than the first section, which is located on the side far from the rotational center of the impeller, and a third section that is an inclined face connecting the first and second sections, the first to third sections being arranged in a width direction of the groove.

A sewage system component spray assembly is attached at a predetermined height above pumps in the interior of the component and has at least one nozzle for spraying liquid downwardly and generally tangential to a center of the sewage system component. Operation of the nozzle causes the liquid to disperse floating material on the sewage surface and creating a rotational flow around the center to direct such material to the pumps.

A sewage system component spray assembly is attached at a predetermined height above pumps in the interior of the component and has at least one nozzle for spraying liquid downwardly and generally tangential to a center of the sewage system component. Operation of the nozzle causes the liquid to disperse floating material on the sewage surface and creating a rotational flow around the center to direct such material to the pumps.