JPS6130840B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to rotary impellers, and more particularly to impellers designed to rotate near the surface of a liquid and aerate the liquid.

Recently, liquid aeration impellers have been used very extensively for surface aeration of wastewater.
Representative examples of such aeration impellers are shown in U.S. Pat. Although such devices generally perform well, they suffer from excessive splashing and misting during operation, inadequate pumping and circulation, and poor impeller visibility. Problems such as clogging have been experienced. Furthermore, these conventional impellers were of fixed diameter and therefore larger or
If a smaller impeller was required, the entire system had to be replaced in the field.

The invention therefore provides an impeller for liquid aeration that includes a support disk fixed to a rotating shaft and having a circular outer edge. The support disk is fixed to the rotational axis and maintained substantially perpendicular to the axis.
A number of impeller blades are secured to the support disk at a distance from the shaft and extend above the top surface of the support disk and below the bottom surface of the cover disk. The blades of the impeller further extend radially outwardly from their circular outer edge, with an upper edge in a plane substantially parallel to the support disk, and the blades being widest at the point closest to the axis of rotation. and a lower edge that tapers so that the blade gradually narrows as it extends radially outwardly from the support disc. Additionally, each blade of the impeller includes flow-directing fins along its lower edge that are widest closest to the axis of rotation and gradually increase in width as the blades extend radially outward from the support disk. It is tapered in such a way that it becomes narrower. Covering means fixed to the blades of the impeller are spaced apart from the upper surface of the support disk and create an air inlet above the upper surface of the support disk, which is drawn near the surface of the liquid by the rotation of the impeller. Reduces the amount of splash caused. In one embodiment, the impeller is
The blades of the impeller are adjustably fixed to the support disk so that the degree of radial extension can be adjusted, and the cover means can be adjustably attached to the upper edge of the blades of the impeller. It includes means for securing.

It is therefore an object of the present invention to provide a liquid aeration impeller that avoids excessive liquid splashing and atomization by producing a relatively low spray profile.

Another object of the present invention is to provide a liquid aeration impeller that significantly improves liquid pumping and circulation compared to previously utilized impellers.

Another object of the present invention is to provide a liquid aeration impeller that operates in a relatively plug-free manner and provides easy access to the interior of the impeller.

Another object of the present invention is to provide a liquid aeration impeller with circulation and aeration characteristics that are highly sensitive to the level of the liquid.

Yet another object of the present invention is to provide an impeller for liquid aeration in which the diameter of the impeller can be varied.

A further object of the invention is to provide a liquid aeration impeller which is relatively simple in construction and therefore easy and inexpensive to manufacture.

Objects, advantages, and novel features of the invention will become apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings.

The surface aeration impeller of the present invention is shown in FIG.
5 will be described in detail.

A surface aeration impeller 10 for aerating the liquid is fixed to a rotating shaft 12. Shaft 12 is coupled to any suitable prime mover (not shown). The impeller 10 has a circular outer edge 16 and upper and lower surfaces 18 and 20.
and a support disk 14, each having a Surface 1
Although 8 and 20 are preferably flat surfaces, it is clear that inclined surfaces are also included within the scope of the present invention. Means are provided for securing the support disc to the axis of rotation 12 so that the support disc 14 is maintained in a substantially perpendicular relationship with the axis 12. Preferably, this fixing means is a hub 22 that is fixed to the shaft 12 with a set screw.

A number of impeller blades 24 are fixed to support disk 14 and spaced from axis 12 . The impeller blades 24 extend radially outwardly from the circular outer edge 16 and extend above the upper disk surface 18 and below the lower disk surface 20. Furthermore, the impeller blades 24 each have an upper edge 26 lying in a plane substantially parallel to the support disk 14 . The blades 24 also each have a lower edge 28 that extends radially outwardly from the support disk 14 such that the width of the blade 24 is widest at a portion 30 closest to the axis of rotation 12 . It has a tapered shape that gradually becomes narrower. impeller blade 24
is preferably curved over the entire length in the radial direction. Although from a theoretical point of view many types of curved shapes are found to be suitable, from the point of view of ease of manufacture it has been found that it is better to have this curvature of a constant radius. It is understood that the use of planar blades is also within the scope of the invention. As shown most clearly in FIG. 3, the impeller blades 24 include a notch 32 along an inner edge 30 adapted to receive the circular outer edge 16 of the support disc 14. The blade 24 can thus be fastened to the support disk 14 in a dovetail manner. Therefore, the blade 24 is connected to the supporting disk 1
4 can be permanently fixed. For example, if the blade 24 and the support disc 14 are made of steel, the blade 24 may be attached to the support disc 14 along the cutout portion 32.
It can also be welded to.

The impeller blades 24 each include a flow directing fin 34 along a lower edge 28 thereof. This fin 34 is also the portion 3 closest to the rotation axis 12.
6 is widest and tapers gradually narrower as the blades 24 extend radially outward from the impeller. This fin 34 is
Preferably, the blade 24 is curved to correspond to the radial curvature of the blade 24.

If the fins 34 and vanes 24 are made of steel, the fins are welded to the blade 24 along the lower edge 28. In an alternative embodiment, the fins 34 and blades 24 can be made of cast aluminum and of integral construction.

A cover means in the form of a cover disc 38 is attached to the disc 14.
Spaced apart from the top surface 18 and secured to the impeller blades 24 to create an air inlet above the disk top surface 18 to reduce the amount of splatter caused by rotation of the impeller near the liquid surface. do. Disk 3
8 preferably includes a circular outer edge 40 and a circular inner edge 42 forming an aperture in the center of the disk. This hole forms an air inlet and allows the cover disk 38 to surround the rotating shaft 12. In terms of manufacturing, it is preferable that both the upper and lower surfaces of the cover disk 38 are flat. In the embodiment of FIG. 3, the cover disc 38 is preferably permanently secured to the top edge 26 of the blade 24 by welding.

A second embodiment of the surface aeration impeller of the present invention will be described in detail with reference to FIGS. 4 and 5. FIG. Like numbers refer to like components throughout this description. This second embodiment is characterized in that means are provided for adjustably fixing the blades 24 of the impeller to the support disk 14, so that the extent to which the blades 24 extend radially relative to the disk 14 can be adjusted. 1st except
This is the same as the embodiment. Furthermore, means are provided for adjustably securing the cover disk 38 to the upper edge 26 of the impeller blades 24 so that the degree of radial extension of the blades 24 can be adjusted. For ease of illustration, planar blades are shown in the embodiments shown in FIGS. 4 and 5. To provide this adjustment, impeller blade 24 includes a pair of flanges 44 and 46 along its stepped top edge. It will be appreciated that the flange 44 may also utilize a curved blade and the flange 44 may be provided on either side of the blade. If a planar blade is used, a gusset is preferably placed on the top of the blade opposite the flange to add stability to the blade. The means for adjustably securing the impeller blades to the support disc 14 includes three mounting holes 48 for each blade 24 aligned radially in the support disc 14. It will be appreciated that holes may be added and the spacing of the holes may be varied if a wider range of adjustment is desired. Additionally, it will be appreciated that the same result can be achieved by providing multiple mounting holes in flange 44. However, if a large number of attachment holes are drilled in the disk 14, only one attachment hole 50 needs to be drilled in the flange 44. Suitable fasteners 52, such as nuts and bolts, may be inserted into the desired mounting holes to properly mount the blade 24 to the support disc 14. Similarly, by drilling two sets of radially aligned mounting holes 52 in the cover disc 38 and placing a pair of mounting holes 54 over the flange 46, the cover disc 38 can be freely adjusted to the upper edge of the impeller blade. Can be fixed. Additionally, the number of mounting holes 50 and the spacing between the mounting holes may be varied depending on the desired amount of adjustment. In addition, the disk 38
Instead, the flange 46 may be provided with a number of mounting holes. In yet another embodiment, rather than a single set of adjustable mounting holes 50 and 48, the entire set of holes may be replaced with slots to provide radial adjustment. In this embodiment, the blade 24 is made of cast aluminum and the flange 4
4, 46 and the blade portion 24 are preferably of integral construction.

In operation of the surface aeration impeller of the present invention, impeller 10 is placed near the surface of the liquid to be aerated. The impeller 10 typically has a support disk 14 during rotation.
is not lowered to the point where it sinks, the inlet air enters the impeller through the hole in the cover disc 38 formed by the edge 42 and passes through the space between the disc 38 and the disc 14. do. As mentioned above, the vane 24
has a tapered lower edge 28, and the fins 36 are also tapered so that the shaft 12
Assuming that the prime mover driving the impeller 10 provides a constant rotational input speed, the mixed power level and therefore the impeller 10
The circulation and aeration characteristics of the liquid can be easily adjusted by simply raising and lowering the impeller relative to the liquid surface. The use of cover disc 38 in combination with flow directing fins 36 provides a relatively low atomization profile, thereby avoiding excessive splashing and atomization of the aerated liquid. Furthermore, the shape of the blades 24 and flow directing fins 36 significantly improves the pumping and circulation effects of the impeller 10 compared to previously utilized impellers. Impeller 10
Since the impeller is of relatively open construction, as is evident from the bottom view shown in Figure 2, the impeller operates relatively free of clogging and it is easy to access the inside of the impeller for repair. You can take advantage of this. If it is desired to change the impeller diameter, simply replace the fasteners 52 into the desired set of mounting holes. Therefore, the diameter of the impeller can be easily adjusted even after installation.

Although what is considered to be a preferred embodiment of this invention has been described, it will be apparent that various modifications may be made to it by those skilled in the art without departing from the invention.
Accordingly, all such modifications are deemed to be within the spirit and scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the surface aeration impeller of the present invention. 2 is a bottom plan view of the impeller shown in FIG. 1; FIG. FIG. 3 is a schematic partial cross-sectional view of the impeller shown in FIG. 1. FIG. 4 is a sectional view of a second embodiment of the impeller shown in FIG. 1. FIG. 5 is an end view of the embodiment shown in FIG. 4. 10... Impeller for surface aeration, 12... Rotating shaft, 14
...support disk, 16...circular outer edge, 18, 26...upper and lower surfaces, 22...hub, 24...impeller blades, 26...upper edge, 28...lower edge, 30...closest to the rotation axis Part, 32... Notch, 34, 36...
Flow guiding fin, 38...Cover disk, 38, 40
...Circular outer edge, 42...Circular inner edge, 44, 46...
Flange, 48, 50, 54...Mounting hole, 52...Fastening tool.

Claims (1)

[Scope of Claims] 1. A liquid aeration impeller fixed to a rotating shaft, comprising: (a) a support disk having a circular outer edge and an upper surface and a lower surface; (b) the support disk comprising: (c) means for securing said support disc to said axis of rotation such that said support disc is maintained substantially perpendicular to said axis; (c) said support disc being spaced apart from said axis when said support disc is secured to said axis; (d) a plurality of blades fixed to the support disk and extending radially outward from the circular outer edge and extending above the top surface of the disk and below the bottom surface of the disk; The blades of the impeller are spaced apart from the top surface of the disk to create an air inlet above the top surface and to reduce the amount of splash caused by the rotation of the impeller near the liquid surface. and a cover means secured to the impeller. 2. A liquid aeration impeller fixed to a rotating shaft, comprising: (a) a support disk having a circular outer edge and upper and lower surfaces; (b) the support disk substantially perpendicular to said shaft; (c) means for securing said support disc to said rotation shaft such that said support disc is secured to said shaft at a distance from said shaft when said support disc is secured to said shaft;
a plurality of blades extending radially outwardly from a circular outer edge and extending above an upper surface of the disk and below a lower surface of the disk, each blade extending in a plane substantially parallel to the support disk. each of said blades having an upper edge within said blades;
The blades are tapered such that the blades are widest at the point closest to the rotational axis and gradually narrow as they extend radially outward from the support disk, and each blade has a width along its lower edge. and flow-directing fins, the fins being tapered to be widest proximate the axis of rotation and gradually narrower as the blades extend radially outwardly from the support disk. (d) fixed to said blade at a distance from the top surface of said support disk, defining an air inlet above said top surface of said disk, and being driven by rotation of said impeller near the surface of said liquid; An impeller further comprising cover means for reducing the amount of splash caused by the impeller. 3. In an impeller for liquid aeration which is adapted to be fixed to a rotating shaft, (a) a support disk having a circular outer edge and an upper surface and a lower surface; (b) said support disk substantially attached to said shaft; (c) a number of blades of an impeller; (d) an air inlet above the top surface of the disk; (e) covering means for reducing the amount of splash caused by rotation of the impeller near the surface of the liquid; (e) blades of the impeller extend radially outward from the circular outer edge; means for adjustably fixing the blades of the impeller to the support disk so as to extend above the upper surface of the disk and below the lower surface of the disk, and to adjust the degree of radial extension; f) means for adjustably fixing the cover means to the upper edge of the blade of the impeller such that the cover means is spaced apart from the upper surface of the disc and the degree of radial extension of the blade can be adjusted; An impeller comprising: