ES2709199T3 - Sludge pump impeller - Google Patents

Abstract

A sludge pump impeller (10) including: - a front cover (50) and a rear cover (51) having an internal main face (54, 53) each with an outer peripheral edge and an axis (XX) central, generally forming the inner main faces (53, 54) right angles with the central axis (XX), the running impeller (10) being able to rotate around the central axis (XX) in a direction of rotation, - a plurality of pumping blades (42) extending from the inner main face of the rear cover (53) to the inner main face of the front cover (54), the pumping blades (42) being arranged in a spaced apart relationship. each of the pumping blades (42) including: - first and second opposite sides (45, 46) where the first lateral face (45) is a lateral pumping or pressure side (45), - an edge (43 ) of attack in the area of the central axis (XX), - a rear edge (44) in the area of the peripheral edge rich exterior of the front and rear covers (54, 53), and - with a passage between adjacent pumping blades, characterized in that the first side face (45) on the front edge (43) is in a plane that forms an acute angle with respect to a plane of the main inner face of the rear cover (53), and the first side face (45) at the rear edge (44) is in a plane that forms an obtuse angle with respect to the plane of the main face inside the rear cover (53) where the angle of the first side face (45) changes progressively when it is moved from the leading edge (43) to the rear edge (44).

Description

DESCRIPTION

Sludge pump impeller

Field of the technique

This description generally refers to runners for centrifugal sludge pumps. Sludge is normally a mixture of liquid and solid particles, and is commonly found in the mineral, sand and gravel and / or dredging industry.

Background of the technique

Centrifugal sludge pumps generally include a pump casing having a pumping chamber therein that may have a volute configuration with an impeller mounted to rotate within the pumping chamber. A transmission shaft is operatively connected to the impeller of the pump to cause rotation thereof, transmission shaft that enters the pump casing from one side. The pump further includes an inlet of the pump which is typically coaxial with respect to the drive shaft and is located on the opposite side of the pump housing to the drive shaft. There is also a discharge outlet that is normally located on the periphery of the pump housing. The pump housing can be in the form of a coating that is enclosed within an outer housing of the pump.

The impeller typically includes a hub to which the drive shaft is operatively connected, and at least one cover. The pumping vanes are provided on one side of the cover with discharge passageways between the adjacent pumping vanes. The impeller can be of the closed type in which two covers are provided with the pumping vanes disposed between them. However, the impeller may be of the "open" face type comprising only one cover.

In some applications, conventional pumping vanes are positioned such that a section through the vane forms an acute angle to the shroud at a pressure surface of the vane and provides a smooth transition from entry to discharge throughout. of the length of the blade.

Two examples of impellers having warped vanes are illustrated in US2010 / 0284812 and US 6,082,000. Document US2010 / 0284812 discloses a centrifugal water pump having an impeller having aerodynamically shaped blades with a thick base (part in contact with the rear cover) tapering towards a thin tip (the part closest to the entrance of the pump). fluid). Although the blades are curved along their length, they do not feel suitable for use as mud pumps. In US 6,082,000, the blades of D2 are typical of the mixed flow type, that is, blades are of the double curvature type. The patent refers to a novel method for producing such alabe. Document EP2570674 describes an erosion by restriction of the impeller blade made of metal lamination, which comprises a core of a first metal material and a resistant wear material, the hardness of the wear material being higher than that of the core material. metal.

For mud pumps that handle heterogeneous sludge (with 0.5 mm typical size sedimentation particles) it is common for there to be solid concentration gradients along the flows in the inlet tube and inside the impeller and casing of the bomb. The concentration gradients are caused by the various forces that act on the particle that include: gravity, fluid resistance and centrifugal forces. As the mud enters the impeller, it has to turn with an angle of 90 ° of flow to go out of the pump and with the forces of inertia and the Coriolis forces (exerted by the blade), the particles of the mud are in its highest concentration at the root of the blade in the rear cover of the impeller, that is, in the area in which a lateral edge of the blade comes into contact with the cover.

A consequence of this flow of concentrated particles along the root of the blade is a high and uneven wear due to the grooving of the impeller at that point, which can prematurely cause the impeller to be ineffective.

Compendium of the description

In a first aspect of the present invention, there is provided a pump impeller that includes:

- a front cover and a back cover having an internal main face with an outer peripheral edge and a central axis, the main internal faces forming a generally right angle with respect to the central axis, the impeller in use being able to rotate about the axis main in a rotation direction,

- a plurality of pumping vanes extending from the internal main face of the covered rear part, the pumping vanes being arranged in a spaced relation, and each pumping vane including:

- first and second opposite side faces where the first side face is a side of pumping or side pressure,

- an anterior edge in the area of the central axis,

- a trailing edge in the area of the outer peripheral edge of the front and back covers, and

- with a passage between adjacent pumping blades,

characterized in that the first side face at the leading edge is in a plane in which it forms an acute angle with respect to a plane of the rear cover, and the first side face at the trailing edge is in a plane forming an obtuse angle with with respect to the plane of the inner main face of the rear cover where the angle of the first side face changes progressively as it moves from the leading edge towards the trailing edge. The configuration of the blade is such that in operation the Coriolis force generated by the blade disperses the particles through the blade at its trailing edge, which reduces wear near the area where the blade rests against the face of the back shell.

In certain embodiments, the first side face at the trailing edge is in a plane that forms an obtuse angle in a range of greater than about 90 ° to about 135 °. In certain embodiments, the first side face at the leading edge is in a plane that forms an acute angle in a range of about 45 ° to less than about 90 °.

The angle of the first side face changes progressively as it moves from the leading edge to the trailing edge of the blade which can be in a continuous form of curvature when moving from the leading edge to the trailing edge, or in multiple straight sectors with different acute angles or obtuse to shape the shape of the pump blade.

The first side face is an anterior face with respect to the direction of rotation, so that the fluid being pumped impacts against it.

In certain embodiments, each pump vane includes a leading edge section terminating at the leading edge of the leading edge section tapering toward the leading edge, and a trailing edge section terminating at the trailing edge of the leading edge section. a back section tapering towards the trailing edge, each pump vane including a main section between the front and back edge sections having a width or thickness that is generally constant from a side edge thereof to an opposite side edge and along of its length from the section of the leading edge to the section of the trailing edge.

In certain embodiments, the first side face is configured in such a way that the surface thereof, in any line between the leading and trailing edges, is 90 ° from one side edge to the other, either flat or linear in the direction of that line. . To put it another way, the first side face is a face of a flat rectangular strip with the leading and trailing edge forming the two shorter sides of the rectangular flat strip and the side edges forming the two longer sides of the strip. flat rectangular strip, said rectangular flat strip is twisted around an axis extending from the leading edge to the trailing edge, and said rectangular flat strip is also curved between the leading edge and the trailing edge so that the first face side is curved backward and the first side face of the rectangular flat strip is linear or flat in the direction of a line drawn from one edge to the other at any point between the leading edge and the trailing edge of the first side face where the line meets each of the lateral edges forming an angle of 90 °.

In certain embodiments the pumping vanes are curved in a longitudinal direction between the leading and trailing edges although in some other embodiments the vane pumping vanes can be straight along their distal length.

In some embodiments, the vanes are curved backward with respect to the direction of rotation of the impeller, although in some applications the direction of curvature may be formed forward with respect to the direction of rotation of the impeller, depending on the nature of the fluid.

An example of a pump impeller including:

- a rear cover having an internal main face with an outer peripheral edge and a central axis, the running impeller which is capable of rotating about the central axis in a direction of rotation,

- a plurality of pumping vanes extending from the inner main face of the rear cover, the pumping vanes disposed in a spaced relation, and each pumping vane including:

- opposite face first and second side,

- opposite side edges one of which is located on the back cover,

- an edge of attack in the area of the central axis and

- a trailing edge in the area of the outer peripheral edge of the back cover, and

- with a passage between adjacent pumping blades,

wherein a line extending from one side edge to the other side edge of the pump vane at the leading edge forms an acute angle with respect to a plane of the main interior face of the rear cover, and a line extending from one side edge to the other side edge of the pump vane at the trailing edge that forms an obtuse angle with respect to the plane of the inner main face of the back cover.

Other aspects, features and advantages will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which form part of this description and which illustrate, by way of example, the main aspects of the present invention.

Brief description of the drawings

In spite of any other forms that may fall within the scope of the apparatus as set forth in the Compendium, specific embodiments of the apparatus will be described below, by way of example, and with reference to the accompanying drawings in which:

Figure 1 illustrates a schematic partial cross-sectional side elevation of a pump incorporating an impeller and a combination of impeller and casing, according to an embodiment of the present invention; Figure 2 illustrates a schematic view of part of an impeller and a pump vane according to an embodiment of the present invention;

Figures 3 to 5 represent sectional views of an impeller cover and an impeller pump blade taken along the lines 1, 2 and 3 of Figure 2 according to the present invention; Y

Figures 6 and 7 are pictorial views of a part of a runner illustrating the characteristics of the pumping vanes according to an embodiment of the present invention.

Figure 8 is a perspective view from above of a runner illustrating the characteristics of the pumping vanes according to an embodiment of the present invention.

Figure 9 is a perspective view from below of an impeller illustrating the characteristics of the pumping vanes according to an embodiment of the present invention.

Figure 10 illustrates an example of a schematic view of part of an impeller and a pump vane according to an embodiment of the present invention.

Detailed description of specific embodiments

Referring to Figure 1, a typical example of a pump 10 including a pump casing or volute 12, a rear casing 14, a front casing 30 and an outlet 18 of the pump is illustrated. An internal camera 20 is adapted to receive an impeller 40 to rotate about the axis of rotation X-X.

The forward liner 30 includes a cylindrical delivery section 32 through which the sludge enters the pump chamber 20. The delivery section 32 has a passage 33 therein, with a first outermost end 34 that can be connected to the supply tube (not shown) and a second innermost end adjacent to the camera 20. The front liner 30 further includes a side wall section 15 which engages in operation with the housing 12 of the pump to form and enclose the chamber 20, the side wall section 15 having an interior face 37. The second end 35 of the front liner 30 has a lip 38 raised therein, which is disposed in a relationship facing the impeller 40.

The impeller 40 includes a hub 41 from which a plurality of circumferentially spaced pump vanes 42 extend. A central portion 47 extends forwardly from the hub to the passageway 33 in the front casing. The impeller further includes a front cover 50 and a rear cover 51, the blades 42 being disposed therebetween.

Referring now to Figure 2, this illustrates a runner according to an embodiment of the present invention. The same reference numerals that were used to identify the parts in Figure 1 are used to identify similar parts in the embodiment of Figure 2. The pumping vanes include a section 60 of the leading edge having a leading edge 43 and a section 61 of the trailing edge having a rear edge 44. The section 60 of the anterior edge tapers towards the inside of the anterior edge 43 and the section 61 of the posterior edge narrows towards the interior of the posterior edge 44. The pumping vanes have a main section 63 between the section 60 of the leading edge and the section 61 of the trailing edge which at any flat height on the rear shroud 51 has a width or thickness 64 which is generally constant from one side edge 56 to the other edge 57 laterally and along its length from the section 60 of the leading edge to the section 61 of the trailing edge.

In FIG. 2, only one example of a pump vane 42 extending between the opposite major internal faces 53, 54 of the covers 50, 51 is shown. Normally, an impeller of this type has a plurality of such pumping blades evenly spaced around the area between the covers 50, 51. Usually three, four or five pumping vanes are common in mud pumps. In this drawing only one pumping vane has been shown for convenience to illustrate the features. As shown in Figure 2, the pump vane 42 is generally arcuate in cross section and includes an inner leading edge 43 and an outer posterior edge 44, opposite side edges 56, 57 and opposite first and second sides 45, 46 between the legs. lateral edges 56, 57, the face 45 being a lateral side of pumping or pressure. Blades of this type are usually referred to as backward curved blades when viewed in the direction of rotation. The lateral edge 56, 57 is disposed against the respective internal faces of the covers 50, 51. The internal faces 53, 54 are generally forming straight angles with respect to the axis XX of central rotation. The face 45 which is a lateral side of pumping or pressure of the pump vane 42 is configured in such a way that the surface thereof in any line between the front and rear edges 43, 44 that are forming an angle of 90 ° from an edge 56 lateral to the other 57 is flat or linear in the direction of that line.

Described in another way, the face 45 can be compared to a face of a rectangular flat strip with the front edge 43 and the rear edge 44 forming the two shorter sides of the rectangular flat strip and the side edges 56, 57 forming each the two respective longer sides of the rectangular flat strip. The rectangular flat strip is twisted about an axis extending from the leading edge 43 to the rear edge 44. In addition to being twisted, the rectangular flat strip is also curved between the leading edge 43 and the trailing edge 44 which makes it easier for that face 45 to be curved backward. A face (i.e. face 45) of the rectangular flat strip that is bent and curved in this manner, is linear or planar in the direction of a line that is drawn from the longer side (which is the side edge 56) to the side. another longer side (i.e. the side edge 57) at any point between the two shorter sides (ie the leading edge 43 and the trailing edge 44) of the rectangular flat strip when the line meets each of the sides longer forming an angle of 90 °.

In certain embodiments, the first face 45 is flat or linear when viewed in any cross section along its length from the leading edge 43 to the trailing edge 44, each cross section being taken at right angles to the lateral edges 56, 57 of the Alabe. Examples of such cross sections are illustrated in Figures 3 to 5 which show cross sections taken along the lines 1, 2 and 3 in Figure 2. As is evident upon seeing these figures, the first face 45 is flat or linear in these cross sections. In other words, it means that the first face 45 is not arched or convex in any of the cross-sectional views in question. In the described embodiment, the second face 46 is also flat or linear when viewed in any cross section.

As illustrated, the inclination angle Y of the side face 45 with respect to the main interior face 53 of the rear cover 51 changes progressively along the blade 42 as it moves from its front edge 43 to its rear edge 44. This change in angle is clearly shown in Figures 3 to 5. The inclination angle Y is also known as the anterior angle of the blade with respect to the direction of rotation of the impeller in operation. As shown in Figure 3, the inclination angle Y is an acute angle at the leading edge 43. Preferably the angle is in a range of about 45 ° to less than 90 °, more preferably the angle is in a range of about 70 ° to about 80 °, and more preferably is about 75 °. The angle changes progressively and, in the position shown in figure 4, it is forming right angles (perpendicular). In the position shown in FIG. 5 at the rear edge 44 of the blade, the angle of inclination is obtuse. Preferably the angle at the trailing edge is in a range from greater than 90 ° to approximately 135 °, more preferably the angle is in a range from about 100 ° to about 130 °, and more preferably is about 110 °.

In operation, the Coriolis force (arrow B in figure 2), which is generated as a result of the rotation in operation of the impeller in the direction of arrow A in figure 2, causes the C particles in a mud or fluid which is being transported by the pump impeller of the present embodiment, are dispersed on the face of the blade as the particles move along the blade from the leading edge to the trailing edge. The arrangement of the blade shape can help to break the concentration gradients of the solid particles within the impeller where the mud particles are at their highest concentration at the root of the blade on the rear cover of the impeller, ie, at the area where a lateral edge of the blade comes in contact with the cover. This can cause a reduction in wear due to the grooving of the impeller at that point.

Figures 6, 7, 8 and 9 illustrate an impeller according to one embodiment. The same reference numbers that were used to identify to identify the pieces in figures 1, 2, 3, 4 and 5 are used to identify similar pieces in the embodiment of figures 6, 7, 8 and 9. Figures 6 and 7 represent the parts of a runner 40 seen from different sides of the discharge passages between the blades 42, and FIGS. 8 and 9 each show a runner 40 in its entirety. As can be seen, the inclination angle of the side face 45 with respect to the main interior face 53 of the rear cover 51 changes progressively along the length of the blades 42 when moving from the leading edge (now shown) to its rear edge 44.

Fig. 10 illustrates a modified form of the arrangement shown in Fig. 2. The same reference numerals used to identify parts in Fig. 2 are used to identify similar parts in the modified form of Fig. 10. The change of the angle of inclination And along the length of the blade 42 as shown in Fig. 10 is greater than the change in the inclination angle Y along the length of the blade 42 shown in figure 2.

In the above description of preferred embodiments, specific terminology has been used for reasons of clarity. However, the invention is not intended to be limited to the specific terms as selected, and it should be understood that each specific term includes all technical equivalents that operate in a similar manner to achieve a similar technical purpose. Terms such as "front" and "back", "internal" and "external", "top", "bottom", "top" and "bottom" and the like are used as words of convenience to provide benchmarks and are not to be interpreted as limiting terms.

The reference in this specification to any previous publication (or information derived from it), or any matter that is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that the previous publication (or information derived from it) or known matter is part of the common general knowledge in the field of effort to which this specification refers.

In this specification, the expression "comprising" must be understood in its "open" sense, that is, in the sense of "include", and therefore it is not limited to its "closed" meaning, which is the sense of "That only consists of". A corresponding meaning should be attributed to the corresponding words "comprises", "understood" and "understands" where they appear.

Furthermore, the foregoing describes only some embodiments of the invention (s), and modifications, additions and / or changes thereof may be made without departing from the scope of the claims, the embodiments being illustrative and not restrictive.

In addition, the invention (s) have been described in relation to what is currently considered to be the most practical and preferred embodiments, it should be understood that the invention should not be limited to the described embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope and scope of the invention (s) as defined in the claims. Also, the various embodiments described above may be implemented in conjunction with other embodiments, for example, aspects of one embodiment may be combined with aspects of another embodiment to give rise to other embodiments. In addition, each feature or independent component of any given set may constitute an additional embodiment.

Table of pieces

Pumping vanes 42 Central part 47 Leading edge section 60 Leading edge 43 Vane entry 48 Departure edge section 61 Exit edge 44 Main section 63 Width or thickness 64 Exit 49 Front cover 50 Back cover 51 First side 45 Second face 46 Side edge 56 Side edge 57

Claims (6)

1. A mud pump impeller (10) that includes: - a front cover (50) and a rear cover (51) having a main face (54, 53), each internal with an outer peripheral edge and a central axis (XX), generally forming the faces (53, 54) main internal straight angles with the central axis (XX), the impeller (10) being capable of rotating around the central axis (XX) in a direction of rotation, - a plurality of pumping vanes (42) extending from the inner main face of the rear cover (53) to the inner main face of the front cover (54), the pumping vanes (42) being arranged in a relationship spaced and each of the pumping vanes (42) that include: - first and second sides (45, 46) opposite sides where the first side face (45) is a side face (45) of pumping or pressure, - an edge (43) of attack in the area of the central axis (X-X), - a rear edge (44) in the area of the outer peripheral edge of the front and rear covers (54, 53), and - with a passage between adjacent pumping blades, characterized in that the first side face (45) at the leading edge (43) is in a plane forming an acute angle with respect to a plane of the main interior face of the rear cover (53), and the first face (45) lateral on the rear edge (44) is in a plane forming an obtuse angle with respect to the plane of the interior main face of the rear cover (53) where the angle of the first side face (45) changes progressively as it moves from the leading edge (43) towards the rear edge (44). 2. A mud pump impeller (10) according to claim 1, wherein the first side face (45) at the leading edge (43) is in a plane forming an acute angle in a range of about 45 ° to less than about 90 °. 3. A mud pump impeller (10) according to claim 1 or claim 2 wherein the first side face (45) at the rear edge (44) is in a plane forming an obtuse angle in a range greater than about 90 ° to about 135 °. A mud pump impeller according to any one of the preceding claims, wherein the first side face (45) is a face of a rectangular flat strip with an anterior edge (43) and a posterior edge (44) forming a the two short sides of the rectangular flat strip and the lateral edges (56, 57) forming the two long sides of the rectangular flat strip, said rectangular flat strip being twisted about an axis extending from the edge (43) anterior to the rear edge (44), said flat rectangular strip being also curved between the front edge (43) and the rear edge (44) in such a manner that the first side face (45) is curved backward and the first face (45) side of the rectangular strip is linear or planar in the direction of a line drawn from one side edge to the other (56, 57) at any point between the anterior edge (43) and the posterior edge (44) of the first side (45) side where the line meets each one of the lateral edges (56, 57) forming an angle of 90 °. 5. A sludge pump impeller (10) according to any one of the preceding claims, wherein the pumping vanes (42) are curved in a longitudinal direction between the leading and trailing edges (43, 44). 6. A mud pump impeller (10) according to claim 5 wherein the vanes (42) are curved backwardly with respect to the direction of rotation of the impeller (10).