CN201250803Y

CN201250803Y - Centrifugal pump

Info

Publication number: CN201250803Y
Application number: CNU2008201531686U
Authority: CN
Inventors: 吴永旭; 见文
Original assignee: Shanghai East Pump Group Co Ltd
Current assignee: Shanghai East Pump Group Co Ltd
Priority date: 2008-09-18
Filing date: 2008-09-18
Publication date: 2009-06-03
Anticipated expiration: 2018-09-18

Abstract

The utility model discloses a centrifugal pump comprising a pump case, a pump shaft arranged in the middle of the pump case, an impeller hub which is key-connected with the pump shaft and a plurality of vanes which are evenly distributed on the positive pressure surface of the impeller hub, and is characterized by further comprising flow guiding vanes with the same number as that of the vanes, wherein the pressure surface of each of the flow guiding vanes and the suction surface of corresponding vanes have a gap. After adopting the technical scheme, the centrifugal pump can effectively prevent flowing separation on the boundary layer. The boundary layer formed on the flow guiding vanes is brought to the main flow before separating, and forms a new boundary layer, and thereby the gap jet centrifugal pump has better effect for eliminating trailing vortex resistance.

Description

A kind of centrifugal pump

Technical field

The utility model relates to the centrifugal pump technical field, particularly a kind of centrifugal pump impeller.

Background technique

When traditional centrifugal pump moved, the whirlpool that flow of fluid produces in the impeller was one of main factor that causes hydraulic loss.As shown in Figure 1, the travelling forward of viscous friction stagnation fluid, and pressure stops that also fluid advances, fluid particle constantly slows down, and has stopped time at the S point finally.The fluid that stops is piled up at the S point, simultaneously because the K point pressure is higher than the S point pressure, fluid flows backwards under the adverse pressure gradient effect, is flowed to the S point and is turned back following current again and go under incoming flow impacts by the K point, so near obvious visible Maelstrom of formation S point.This whirlpool is separated boundary layer and vacuum side of blade from the S point, this just cries the separation in boundary layer.The boundary layer is left behind the vacuum side of blade the carrying of outflow and is floated downstream down and the fluid of back mixes whirlpool district of formation, is called the trailing vortex district.Because the appearance in trailing vortex district will cause the trailing vortex resistance that the motion blade is very big, it equals to act on pressure on the blade surface in the summation of coming flow path direction upslide shadow.In the viscous resistance of motion blade, when does not separate in the boundary layer, be based on frictional resistance, in a single day separation trailing vortex resistance that the boundary layer has still taken place just becomes and surfaces, and its big I is up to tens times of frictional resistance.This shows, design a kind of centrifugal pump impeller that can eliminate the trailing vortex resistance and seem particularly important.

The model utility content

Technical problem to be solved in the utility model provides a kind of centrifugal pump impeller, and this centrifugal pump impeller has extraordinary elimination trailing vortex resistance effect.

Technical problem to be solved in the utility model can be achieved through the following technical solutions:

A kind of centrifugal pump, comprise pump case, be arranged on pump shaft in the middle of the described pump case, be good for the impeller boss that is connected and be distributed in some blades on the impeller boss pressure surface with pump shaft, it is characterized in that, also comprise the guide vane that quantity equates with blade quantity, described guide vane is arranged on the impeller boss and is positioned at the become a mandarin inboard of end of described blade, has slit between the pressure side of described each guide vane and the suction surface of described corresponding blade.

Slit width between the suction surface of the pressure side of described guide vane and described corresponding blade is 3-8mm.This slit length is 5～10mm.

The thickness of the end that becomes a mandarin of the utility model guide vane is greater than the thickness that goes out the stream end, and preferred version is that the thickness that the stream end approaches 0.

Find that in practice process the import laying angle of described guide vane 3 is taken as consistent with traditional waterpower design, with the efficient that mainly improves pump about 5～10%; When the design of the import laying angle of guide vane designed big 6～12 ° than traditional waterpower, then the pump operation optimal working point was partial to large-capacity point, and efficient traditional waterpower optimum condition of comparing improves about 5～10%.Therefore the import laying angle of the utility model guide vane is 20-35 °.

The utility model is divided into blade and guide vane with the design of traditional blades waterpower, utilize the energy of main flow itself to pass through the blocking zone that slit is guided to the high-pressure liquid of pressure side suction surface, to the energy of the fluid feeding additional that blocked in the boundary layer, thereby prevent the segregation phenomenon of boundary layer flow.The boundary layer that forms on guide vane just is brought in the main flow when also not separating and has gone, and from the end that becomes a mandarin of blade, form a new boundary layer, than under the advantageous conditions, the new boundary layer of this kind will last till going out stream end trailing edge and not separating of blade always, thereby improve the efficient of impeller under the same operating mode effectively.

Description of drawings

Fig. 1 is the schematic representation that the blade suction surface of existing centrifugal pump impeller forms the trailing vortex district.

Fig. 2 is the working principle schematic representation of the utility model centrifugal pump impeller.

Fig. 3 is the structural representation of a preference of the utility model centrifugal pump impeller.

Fig. 4 is the left view of Fig. 3.

Embodiment

For technological means, creation characteristic that the utility model is realized, reach purpose and effect is easy to understand, below in conjunction with concrete diagram, further set forth the utility model.

Referring to Fig. 2, Fig. 3 and Fig. 4,

A kind of centrifugal pump comprises pump case, is arranged on pump shaft in the middle of the described pump case, is good for the impeller boss 1 that is connected with pump shaft and is distributed in four blades 2 on impeller boss 1 pressure surface.Certainly the quantity of blade 2 also is not limited to four, can be other quantity, and this mainly requires to be provided with according to characteristic of centrifugal pump design.Blade 2 does not have any difference in the position of impeller boss 1 and the shape of blade 2 with size and existing centrifugal pump impeller, and this point is not an emphasis of the present utility model, and right and wrong Changshu is known to those skilled in the art, therefore is not described in detail at this.Also comprise a front shroud 3 as centrifugal pump impeller, this front shroud 3 be by four screw screwing in from impeller boss 1 back pressure face on impeller boss 1.

Centrifugal pump impeller of the present utility model can be made full-open type or semi-open type, can be founding casting impeller or resin type impeller.No matter be the sort of structural type centrifugal pump impeller, all also comprise and four blades, 2 corresponding four guide vanes 4, four guide vanes 4 can adopt integrated mode to be molded directly within on the impeller boss 1, also can as the mode of Fig. 3 and Fig. 4 by the screw that screws in from impeller boss 1 back pressure face on impeller boss 1, perhaps adopt the mode of welding to install.Certainly the utility model should preferentially adopt integrated mode to be molded directly within on the impeller boss 1 under the prerequisite of process conditions permission.

The mounting point of guide vane 4 still is described in conjunction with Fig. 3 and Fig. 4 when the utility model, at first have four identical blind holes of quantity and four blades 2 from the pressure surface of impeller boss 1, have two or more small through hole at the bottom of the hole of each blind hole, so that pass in order to two or more screws that guide vane 4 is installed.Adopting two or more screw main purposes is disposablely to install guide vane 4, if only adopt a screw, just need between guide vane 4 and impeller boss 1, a position structure be set, so correspondingly can cause the increase of whole centrifugal pump impeller cost.

The structure of four guide vanes 4 is all identical, all is to be made of a guide vane body 41 and a Cylindrical object 42, has two or more screws on Cylindrical object 42.When Cylindrical object 42 is inserted in the blind hole of impeller boss 1, pass in the screw that impeller boss 1 is screwed into Cylindrical object 42 with two or more screws, four guide vanes 4 can be installed on the impeller boss 1.

Four guide vanes 4 are distributed on the impeller boss 1, each guide vane 4 is positioned at the become a mandarin inboard of end 21 of corresponding blade 2, referring to Fig. 2, has certain slit 5 between the suction surface 23 of guide vane body 41 pressure sides 413 of guide vane 4 and corresponding blade 2, slit 5 width are 3-8mm, and this slit length is 5～10mm.After this slit 5 is set, the energy that utilizes main flow itself is guided to the blocking zone of blade 2 suction surfaces 23 through slit 5 with the high-pressure liquid of pressure side, to the energy of the fluid feeding additional that blocked in the boundary layer, thereby prevents the segregation phenomenon of boundary layer flow.The boundary layer that forms on guide vane 4 just is brought in the main flow when also not separating have been gone, and hold 21 from becoming a mandarin of blade 2, form a new boundary layer, than under the advantageous conditions, the new boundary layer of this kind will last till going out stream end 22 trailing edges and not separating of blade 2 always, thereby improve the efficient of impeller under the same operating mode effectively.

Guide vane body 41 be shaped as similar fairshaped wing shapes, pressure side 413 is streamlined, suction surface 414 is near a plane, and the thickness of the end 411 that becomes a mandarin of guide vane body 41 is greater than the thickness that goes out stream end 412, and preferred version is that the thickness that stream end 412 approaches 0.

Find that in practice process the import laying angle of guide vane body 41 is taken as consistent with traditional waterpower design, with the efficient that mainly improves pump about 5～10%; When the design of the import laying angle of guide vane body 41 designed big 6～12 ° than traditional waterpower, then the pump operation optimal working point was partial to large-capacity point, and efficient traditional waterpower optimum condition of comparing improves about 5～10%.Therefore the import laying angle of the utility model guide vane body 41 is 20-35 °.

With reference to figure 2, the utility model is divided into blade 2 and guide vane 4 with the design of traditional blades waterpower, utilize the energy of main flow itself to pass through the blocking zone that slit 5 is guided to the high-pressure liquid of pressure side suction surface, to the energy of the fluid feeding additional that blocked in the boundary layer, thereby prevent the segregation phenomenon of boundary layer flow.The boundary layer that forms on the A-B section of guide vane 4 just is brought in the main flow when also not separating have been gone, and from the C point, forms a new boundary layer, and than under the advantageous conditions, the new boundary layer of this kind will last till trailing edge (D point back) always and not separate.

Can understand the XA40/32 type pump product that is applied to centrifugal pump impeller of the present utility model from table 1 exists

Performance data contrast before and after table 1 pump product technology is improved

More than show and described basic principle of the present utility model, major character and advantage of the present utility model.The technician of the industry should understand; the utility model is not restricted to the described embodiments; that describes in the foregoing description and the specification just illustrates principle of the present utility model; the utility model also has various changes and modifications under the prerequisite that does not break away from the utility model spirit and scope, and these changes and improvements all fall in claimed the utility model scope.The claimed scope of the utility model is defined by appending claims and equivalent thereof.

Claims

1. centrifugal pump, comprise pump case, be arranged on pump shaft in the middle of the described pump case, be good for the impeller boss that is connected and be distributed in some blades on the impeller boss pressure surface with pump shaft, it is characterized in that, also comprise the guide vane that quantity equates with blade quantity, have slit between the pressure side of described each guide vane and the suction surface of described corresponding blade.

2. a kind of centrifugal pump according to claim 1 is characterized in that, described guide vane is arranged on the impeller boss and is positioned at the inboard that described blade becomes a mandarin and holds.

3. a kind of centrifugal pump according to claim 1 is characterized in that, the slit width between the suction surface of the pressure side of described guide vane and described corresponding blade is 3-8mm, and this slit length is 5～10mm.

4. a kind of centrifugal pump according to claim 1 is characterized in that, the thickness of the end that becomes a mandarin of described guide vane is greater than the thickness that goes out the stream end.

5. a kind of centrifugal pump according to claim 4 is characterized in that, the thickness that goes out the stream end of described guide vane approaches 0.

6. a kind of centrifugal pump according to claim 1 is characterized in that, the import laying angle of described guide vane is 20-35 °.