Background of invention

The invention relates to an impeller according to the preamble of claim 1. The invention also relates to a turbine device, such as a pump or a pump element, according to the preamble of claim 13.

From the publication US 4,628,391, there is known a method for dispersing two phases in liquid-liquid extraction, and a circulation dispersion contactor for realizing said method. The circulation dispersion contactor introduced in said publication US 4,628,391 comprises an impeller including a round disk, a round annular disk in parallel with said round disk, provided with a round suction inlet for receiving fluid inside the impeller through the round suction inlet, and arched blades arranged in between the round disk and the round, annular disk, the blades of which are at their first edges connected to the round disk, and at their second edges connected to the round, annular disk, so that in between the arched blades, there are formed blade ducts, through which fluid is discharged from the impeller.

Brief description of invention

The object of the invention is to realize an impeller and a turbine device with an efficient operational performance.

The object of the invention is achieved by an impeller according to the independent claim 1.

Preferred embodiments of the impeller according to the invention are set forth in the dependent claims 2 - 12.

The invention also relates to a turbine device according to the independent claim 13.

Preferred embodiments of the turbine device according to the invention are set forth in the dependent claims 14 - 27.

By suitably placing the center of the curvature, it is possible to affect the dispersion capacity of the impeller, i.e. the dispersion of gases and liquids in another liquid, in case the impeller or the turbine device is used in a device designed for dispersion, such as an aeration pump, or a mixer for mixing two or several liquid or solution phases together. By using in the impeller such arched blades where the horizontal section shape of the blade forms part of a circular arch with the center of the curvature located at the distance of more than roughly 1R from the center axis of the impeller, for instance at 1.20R, R being the radius of the impeller, there is achieved an impeller with a reduced dispersion capacity.

Respectively, by using in the impeller such arched blades where the horizontal section shape of the blade is part of a circular arch with the center of the curvature located at the distance of less than roughly 1R from the center axis of the impeller, for instance at 0.85R, there is achieved an impeller with an increased dispersion capacity. For example in aeration applications, such as in water aeration pumps, a high dispersion capacity, i.e. a high capacity of mixing air to water, is advantageous.

In a preferred embodiment of an impeller and turbine device according to the invention, the curvature of the arched blades is such that the arched blades can be considered to form part of a circular arch with a radius of about 1,43R, where R is the impeller radius.

In a preferred embodiment of the impeller and turbine device according to the invention, the diameter of the annular round suction inlet of the impeller is about 0.58D, where D is the impeller diameter.

In a preferred embodiment of the impeller and turbine device according to the invention, the height of the blade ducts formed in between the arched blades of the impeller in between the round disk and the round annular disk is about 0.2 ID, where D is the impeller diameter.

List of drawings

In the specification below, preferred embodiments of the invention are described in more detail with reference to the appended drawings, where

Fig 1 illustrates an impeller provided with a drive shaft,

Figure 2 shows the impeller provided with a drive shaft, illustrated in Figure 1 , from another view angle and in partial cross-section,

Figure 3 shows the impeller provided with a drive shaft, illustrated in Figure 1 , shown in a section along the line A-A of Figure 1,

Figure 4 shows an alternative embodiment for the structure illustrated in Figure 3,

Figure 5 is an exemplary illustration of a turbine housing provided with an impeller, and Figures 6 and 7 illustrate the principles of the measurement design of the impeller.

Detailed description of invention

Figures 1 and 2 illustrate an impeller 2 provided with a drive shaft 1, which impeller can be used for example in a pump of the type described in the drawing. The pump illustrated in Figure 5 comprises two superimposed turbine devices.

First of all, the invention relates to an impeller 2.

The impeller 2 includes a round disk 4.

In addition, the impeller 2 includes, in parallel with the round disk 4, a round annular disk 5 that is at the center provided with a round suction inlet 6 for receiving fluid (not illustrated) inside the impeller 2 through the round suction inlet 6.

Moreover, the impeller 2 includes, in between the round disk 4 and the round annular disk 5, arched blades 7 that are at their first edges attached to the round disk 4 and at their second edges attached to the round annular disk 5, so that blade ducts 8 are formed in between the arched blades 7 for removing fluid from inside the impeller 2.

The horizontal section shape of the arched blades 7 forms part of an imaginary circular arch or circular arch 9, the center of the curvature 10 of said arch being located at a distance 0.7R - 1.3R from the center axis 11 of the impeller 2, said center axis also being the axis of revolution 18 of the impeller 2, in which case R is the radius of the impeller 2. In Figure 7, the distance of the circular arch 9 from the center axis 11 of the impeller is denoted with the reference mark Rl, and the radius of the impeller 2 is denoted with the reference mark R.

The arched blades 7 are advantageously identical in shape, and each arched blade 7 is advantageously placed symmetrically at the same distance from the center axis 11 of the impeller 2.

In the drawings, the round annular disk 5 of the impeller 2 has an inner arc 12 and an outer arc 13, and each blade arc extends from the inner arc 12 to the outer arc 13. In the drawings, the arched blades 7 are underneath covered by the round annular disk 5, whereas the upper structure of the impeller is realized by a uniform, horizontal round disk 4.

The radius of the circular arch 9 is advantageously within the range 1.0R - 1.8R, preferably about 1.43R, where R is the radius of the impeller 2. In Figure 7, the radius of the circular arch 9 is denoted with the reference mark R2, and the radius of the impeller 2 is denoted with the reference mark R.

The center of the curvature 10 of the circular arch 9 is advantageously located at the distance 0.85R - 1.2R from the center axis 11 of the impeller 2, preferably at the distance of about 1.0R from the center axis 11 of the impeller 2, where R is the radius of the impeller 2. In Figure 7, the distance of the circular arch 9 from the center axis of the impeller 11 is denoted with the reference mark Rl .

The diameter X of the round suction inlet 6 of the round annular disk 5 in the impeller 2 is advantageously within the range 0.54D - 0.62D, more advantageously within the range 0.56D - 0.60D, and preferably about 0.58D, where D is the diameter of the impeller 2. In Figure 6, the diameter of the impeller 2 is denoted with the reference mark D, and the diameter of the round suction inlet 6 is denoted with the reference mark X.

The height Y of the blade ducts in the impeller 2 between the round disk 4 and the round annular disk 5 is advantageously within the range 0.19D - 0.23D, more advantageously within the range 0.20D - 0.22D, and preferably about 0.2 ID, where D is the diameter of the impeller 2. In Figure 6, the diameter of the impeller 2 is denoted with the reference mark D, and the height of the blade ducts 8 is denoted with the reference mark Y.

The number of the blade arcs is advantageously within the range 14 - 18, advantageously within the range 15 - 17. The drawings illustrate impellers 2 with 16 blade arcs.

The blade arcs are advantageously arranged at regular intervals.

The impeller 2 comprises advantageously, but not necessarily, an inlet cone 14 placed inside the impeller 2, in the middle thereof, said inlet cone 14 being connected to the round disk 4 and having surfaces that are curved in vertical section and at least partly represent circular arches and/or parabolic arches. The height of this kind of inlet cone 14 is advantageously, but not necessarily, within the range 0.10D - 0.15D, and preferably about 0.13D, where D is the diameter of the impeller 2. In Figure 6, the diameter of the impeller 2 is denoted with the reference mark D, and the height of the inlet cone 14 is denoted with the reference mark Z. This type of inlet cone 14 has advantageously, but not necessarily, a sharp tip 15 for balancing the absorption of the fluid in the rotary impeller 2.

The outer diameter of the round disk 4 corresponds preferably, but not necessarily, essentially to the outer diameter of the round annular disk 5.

The invention also relates to a turbine device such as a pump or pump element, said turbine device including a turbine housing 3, comprising an inlet 16 for conducting fluid to the turbine housing 3, and an outlet 17 for conducting fluid out of the turbine housing 3, and inside the turbine housing 3 an impeller 2, which can be rotated in the turbine housing 3 around an axis of revolution 18 with respect to the turbine housing 3. The impeller 2 of the turbine device comprises a round disk 4 and, in parallel with the round disk 4, a round annular disk 5 that is at the center provided with a round suction inlet 6 for receiving fluid inside the impeller 2 through the round suction inlet 6.

Moreover, the impeller 2 of the turbine device comprises, in between the round disk 4 and the round annular disk 5, arched blades 7 that are at their first edges attached to the round disk 4 and at their second edges attached to the round annular disk 5, so that blade ducts 8 are formed in between the arched blades 7 for removing fluid from inside the impeller 2.

The round suction inlet 6 of the impeller 2 of the turbine device is arranged centrally with respect to the central inlet 16 of the turbine housing 3 for receiving fluid in the impeller 2 through the round suction inlet 6.

Fluid is arranged to be discharged from inside the impeller 2 to the turbine housing 3 and further from the turbine housing 3 through the outlet 17 of the turbine housing 3 to the outside of the turbine housing 3.

The horizontal section shape of the arched blades 7 forms part of a circular arch 9, the center of curvature 10 of said circular arch 9 being located at a distance 0.7R - 1.3R from the center axis 11 of the impeller 2, in which case R is the radius of the impeller 2. In Figure 7, the distance of the circular arch 9 from the center axis 11 of the impeller is denoted with the reference mark Rl, and the radius of the impeller 2 is denoted with the reference mark R.

In addition, the impeller 2 of the turbine device comprises, in parallel with the round disk 4, a round annular disk 5 that is at the center provided with a round suction inlet 6 for receiving fluid (not illustrated) inside the impeller 2 through the round suction inlet 6.

Moreover, the impeller 2 of the turbine device comprises, in between the round disk 4 and the round annular disk 5, arched blades 7 that are at their first edges attached to the round disk 4 and at their second edges attached to the round annular disk 5, so that blade ducts 8 are formed in between the arched blades 7 for removing fluid from inside the impeller 2.

The horizontal section shape of the arched blades 7 forms part of a circular arch 9, the center of the curvature 10 of said arch being located at a distance 0.5R - 1.5R from the center axis 11 of the impeller 2, said center axis also being the axis of revolution 18 of the impeller 2, in which case R is the radius of the impeller 2.

The arched blades 7 are advantageously identical in shape, and each arched blade 7 is advantageously placed symmetrically at the same distance from the center axis 11 of the impeller 2. In the drawings, the round annular disk 5 of the impeller 2 has an inner arc 12 and an outer arc 13, and each blade arc extends from the inner arc 12 to the outer arc 13. In the drawings, the arched blades 7 are underneath covered by the round annular disk 5, whereas the upper structure of the impeller is realized by a uniform, horizontal round disk 4.

The radius of the circular arch 9 is advantageously within the range 1.0R - 1.8R, preferably about 1.43R, where R is the radius of the impeller 2. In Figure 7, the radius of the circular arch 9 is denoted with the reference mark R2, and the radius of the impeller 2 is denoted with the reference mark R.

The center of the curvature 10 of the circular arch 9 is advantageously located at the distance 0.85R - 1.2R from the center axis 11 of the impeller 2, preferably at the distance of about 1.0R from the center axis 11 of the impeller 2, where R is the radius of the impeller 2. In Figure 7, the distance of the circular arch 9 from the center axis of the impeller 11 is denoted with the reference mark Rl .

The diameter X of the round suction inlet 6 in the round annular disk 5 in the impeller 2 is advantageously within the range 0.54D - 0.62D, more advantageously within the range 0.56D - 0.60D, and preferably about 0.58D, where D is the diameter of the impeller 2. In Figure 6, the diameter of the impeller 2 is denoted with the reference mark D, and the diameter of the round suction inlet 6 is denoted with the reference mark X.

The height Y of the blade ducts 8 of the impeller 2 between the round disk 4 and the round annular disk 5 is advantageously within the range 0.19D - 0.23D, more advantageously within the range 0.20D - 0.22D, and preferably about 0.2 ID, where D is the diameter of the impeller 2. In Figure 6, the diameter of the impeller 2 is denoted with the reference mark D, and the height of the blade ducts 8 is denoted with the reference mark Y.

The number of the blade arcs is advantageously within the range 14 - 18, advantageously within the range 15 - 17. The drawings illustrate impellers 2 with 16 blade arcs.

The blade arcs are advantageously arranged at regular intervals.

The impeller 2 includes advantageously, but not necessarily, an inlet cone 14 placed inside the impeller 2, in the middle thereof, said inlet cone 14 being connected to the round disk 4 and having surfaces that are curved in vertical section and at least partly represent circular arches and/or parabolic arches. The height of this kind of inlet cone 14 is advantageously, but not necessarily, within the range 0.10D - 0.15D, and preferably about 0.13D, where D is the diameter of the impeller 2. In Figure 6, the diameter of the impeller 2 is denoted with the reference mark D, and the height of the inlet cone 14 is denoted with the reference mark Z. This type of inlet cone 14 has advantageously, but not necessarily, a sharp tip 15 for balancing the absorption of the fluid into the rotary impeller 2.

The outer diameter of the round disk 4 corresponds preferably, but not necessarily, essentially to the outer diameter of the round annular disk 5.

The diameter X of the central inlet 16 of the turbine housing 3 is advantageously, but not necessarily, essentially the same as the diameter of the round suction inlet 6 of the round annular disk 5 in the impeller 2.The suction inlet 16 has advantageously, but not necessarily, a circular cross-section.

If the suction inlet 16 has a circular cross-section, the diameter of the suction inlet 16 of the turbine housing 3 is advantageously, but not necessarily, essentially the same as the diameter X of the round suction inlet 6 of the round annular disk 5 in the impeller 2.

Moreover, the turbine device may include impeller rotation means (not shown in the figures) for rotating the impeller 2 in the turbine housing 3.

Figures 3 and 4 illustrate two impeller solutions that demonstrate how the dispersion capacity of the impeller 2 can be affected by the design of the blade arcs. The impellers illustrated in Figures 3 and 4 can both be compared with a basic situation where the center of the curvature of the circular arcs of the impeller blades is located at a distance 1.0R from the center of the center axis of the impeller. When the distance of the centers of curvature of the circular arches of the blades is reduced to 0.85R from the center of the center axis of the impeller, the dispersion capacity of said impeller can be increased, which is advantageous in some aerator applications. Respectively, when the distance of the centers of the curvature of the circular arches of the blades is extended to 1.20R from the center of the center axis of the impeller under inspection, the dispersion capacity of said impeller can be reduced, which in turn is a useful feature when dispersing solutions that are susceptible to emulsion. In that case, there is often needed a capacity for a high solution output with said impeller, at the same time as the delivery height can be decreased within certain limits.

Examples

A series of comparing test was carried out by using a set of different impellers in a dispersion pump in order to compare an impeller according to prior art and an impeller of find out how efficient various embodiments of an impeller according to the invention is. In each tests pumping constants describing the effectiveness of the impeller was calculated. The higher the pumping constant, the more effective is the impeller. Example 1

In this test a comparing test was made between two impellers each having a diameter D, a diameter of the round suction inlet that was 0.52D, where D is the diameter of the impeller, and a number of the blades that was 12.

In an impeller according to the prior art the height of the blade ducts Y (i.e. the distance between the round disk and the round annular disk provided with the round suction inlet) was 0.16D, where D is the diameter of the impeller. In the other impeller ("new impeller") the height of the blade ducts Y was correspondingly 0.21D, where D is the diameter of the impeller.

The tests were conducted at three speeds of rotation: 230 rpm, 290 rpm and 360 rpm. At each speed, a pumping constant showing the effectiveness was calculated with the following equation:

K _V = V/ND ³ (1) where K _v is the pumping constant, N is the speed of rotation (rpm), and V is the volume flow (volume / time unit)

Example 2 In this test a comparing test was made between two impellers each having a diameter D of the impeller, a diameter of the round suction inlet that was 0.52D, where D is the diameter of the impeller, and a height of the blade ducts Y (i.e. the distance between the round disk and the round annular disk provided with the round suction inlet) that was 0.16D, where D is the diameter of the impeller.

In an impeller according to the prior art the number of the blades was 12 and in the other impeller ("new impeller") the number of the blades was correspondingly 16. The tests were conducted at three speeds of rotation: 230 rpm, 290 rpm and 360 rpm. At each speed, a pumping constant showing the effectiveness was calculated with the following equation: K _V =V/ND ³ (2) where K _v is the pumping constant, N is the speed of rotation (rpm), and V is the volume flow (volume / time unit)

Example 3

In this test was a comparing test made with two impellers each having a diameter D of the impeller, a number of the blades that was 12, and a height of the blade ducts Y (i.e. the distance between the round disk and the round annular disk provided with the round suction inlet) that was 0.16D, where D is the diameter of the impeller.

In an impeller according to the prior art the diameter X of the round suction inlet was 0.52D, where D is the diameter of the impeller, and in the other impeller ("new impeller") the diameter X of the round suction inlet was correspondingly 0.58D, where D is the diameter of the impeller.

The tests were conducted at three speeds of rotation: 230 rpm, 290 rpm and 360 rpm. At each speed, a pumping constant showing the effectiveness was calculated with the following equation:

K _v = V/ND ³ (3) where K _v is the pumping constant, N is the speed of rotation (rpm), and V is the volume flow (volume / time unit) rpm Prior art New impeller

230 0.157 0.165 290 0.165 0.175

360 0.166 0.179

To a person skilled in the art, it is obvious that along the development in technology, the basic idea of the invention can be realized in many different ways. Thus the invention and its various embodiments are not exclusively restricted to the examples described above, but they can be modified within the scope of the patent claims.