CA1038509A - Device for aerating foaming liquids - Google Patents

Abstract

Abstract of the Disclosure A hollow shaft driven by a motor is submerged at its lower end in a foaming liquid in a container, where the shaft is provided with a propeller and with opening through which air supplied to the shaft is discharged into the liquid. The hollow shaft is surrounded by a tube open at both ends and with its upper and located at least partly below the liquid level in the container, the tube being posi-tioned relative to the propeller to cause the latter to suck foam through the tube's upper end and introduce the foam into the liquid.

Description

` ~o3~5~g The present invention relates to a device for generating ;
foaming liquids in containers, such as latrine or manure pits and the like, the device having a hollow shaft submerged into the con-tainer and connected to a driving motor, the end of the shaft oppo-site to the motor being provided with a propeller and with openings for the discharge of air supplied through the hollow shaft. ;
In prior devices of this type, the llquid in the container is ;
vigorously agitated while air is blown into the liquid. The air flows through the liquid in the form of bubbles and is collected as a foam at the liquid surface. Pathogenic microorganisms contained in the liquid are killed after the liquid has been agitated and ~ ;
supplied with air for a certain time, whereby the odor of the liquid is eliminated.
These prior de~ices have the disadvantages that a high foam layer is formed above the liquid surface and that the propeller does -~
not generate a flow which revolves all layers of the liquid, so that :: ~
it is necessary to maintain an agitation during a relatively long ~
period of time. ~ ;
It has been proposed to reduce or eliminate the foam layer at ;
the surface of the liquid by providing a rigid shaft carrying the -propeller and located inside a tube submerged into the liquid, the end of the tube facing the driving motor being situated above the liquid surface. In this known embodiment, the air is blown into the ~` -liquid through the tube by means of the propeller, and at the same time the foam floating on the liquid surface is sucked away. This ~ -known device has the disadvantage that it does not effect a revol-ving flow of the liquid and does not provide a sufficient supply of ~;
air, so that the desi:red effect of odor reduction is attained only very slowly.
It is the principal object of the invention to eliminate ~ .

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~La3ss~s ~, the disadvantages of these known devices. According to the invention, this is accomplished in that the hollow shaft is surrounded by a tube opPn at both ends, the end of the tube facing the motor being situated at least partially below the level of the liquid in the container, and the tube being positioned to cause the propeller to suck oam through the opening of the tube situated at the liquid level and introduce said foam into the liquid. According to a prefeTred embodi-ment of the invention> the end of the tube facing the motor is cham-fered. Also, in order to provide a smooth operation and avoid shaking of the frame carrying the device, it is preferred that the tube together with the motor and the hollow shaft carrying the propeller, be freely suspended above the container.
The invention will now be described more in detail in the follow ing, reference beiTIg made to the accompanying drawing in whlch the single illustration is a vertical sectional view of an embodiment, chosen by way of example, of the present device.
A container 1 made of concrete is filled with liquid manure 2.
There i5 a l~yer of foam 8 on the liquid surface. A tube 6, submerged in the liquid, is cham~ered at its upper end in the range of the liquid level, as shown at 6a, so that liquid as well as foam can enter the upper opening of the tube. A propeller 7, connected to a driving motor 3 by means of a hollow shaft 5, is provided inside the tube 6.
The latter is supported through rods 9 by the motor housing. The unit consisting of the motor 3, shaft 5, propeller 7 and tube 6 is suspen-ded by means of a cardan joint 4. The hollow shaft 5 in the vicinity ~
of the motor 3 has openings 10 and in the vicinity of the propeller -has openings ll for ~ucking in air and blowing out air, respectively.
~hen the motor runs, liquid as well as foam are sucked in through the inlet opening 6a o the tube 6 by means of the propeller 7. The -air sucked in through the openings 10 and the hollow shaft is swept

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- away at the outlet end of the tube by the ~low effected in the axial . ............ " , direction of the tube. In the drawing, the liquid flow is shown by 1 .~............ .
continuous arrows and the movement of the air bubbles by dashed arrows.
~' The drawing shows that by means of the invention all liquid is revolved and between the bottom of the container and the liquid surface/is thus ;~
enriched with air. ~;

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a device for aerating foaming liquid in a contain-er, the combination of a hollow shaft submerged at its lower end in said liquid in the container, a driving motor connected to the hollow shaft for rotating the shaft, a propeller secured to said submerged end of the shaft, said submerged end of the shaft having openings through which air supplied to the hollow shaft is discharged into said liquid, and a tube surrounding the hollow shaft and open at its upper and lower ends, the upper end of the tube being chamfered and the upper open end of the tube being located partly above and partly below the level of said liquid in the container, the tube being positioned to cause said propeller to suck foam through the upper end of the tube and introduce the foam into the liquid.