JPH1182390A - Guide impeller vane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fit the characteristic of a pump to a desired specification by a simple replacing operation. SOLUTION: The water of which the pressure is increased by an impeller 3, is discharged to a downstream through a guide impeller vane 6. A part at an upstream side with respect to a peak part of the guide impeller vane, of the guide impeller vane, is a partial guide impeller vane 6a, and this partial guide impeller vane 6a can be replaced. The partial guide impeller vane 6a to be fitted to the desired specification, is selected from plural kinds of partial guide impeller vanes having the vane inlet angles and the effective passage widths different from each other, to be mounted. That is, in a case when the performance is improved at a large capacity side, the partial guide impeller vane 6a of large vane inlet angle and large port is used, and in a case when the performance is improved at a small capacity side, the partial guide impeller vane 6a of small vane inlet angle and small port is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide blade applied to a single-stage or multi-stage mixed flow pump.

[0002]

2. Description of the Related Art In a mixed flow pump, factors for raising the head from the inlet to the outlet of the pump are a rotating portion (impeller or impeller) having several blades and a stationary portion (guide blade or diffuser). The impeller rotates to impart a centrifugal force to the fluid (ie, water) to increase the pressure, and the guide vanes return the flow in the axial direction to minimize the loss. The size of the effective passage (port) at the entrance of the guide vane changes the head and the maximum efficiency point flow rate in the pump performance characteristics.

FIG. 4 shows a conventional mixed flow pump (a pump in which the flow in an impeller is oblique when viewed from the axial direction). As shown in FIG. 1, an impeller 3 is attached to an impeller boss 2 that rotates integrally with the main shaft 1. A part of the casing 4 which is a stationary part (a part on the suction side) is a suction bell mouth 5, and a guide blade 6 and a guide blade boss 7 are arranged inside the casing 4.

In such a mixed flow pump, fluid (water) whose pressure has been increased by the impeller 3 passes through the guide blade 6 and is discharged downstream. In the case of casting, the guide blades (the guide blades 4, the guide blade boss 7, and the portion of the casing 4 where the guide blades 6 are arranged) are integrally formed. Therefore, when the blade angle at the entrance of the guide blade 6 is not appropriate, it is very difficult to correct the blade angle.

[0005]

In the prior art, the entire guide blade portion (the guide blade 4, the guide blade boss 7, and the portion of the casing 4 where the guide blade 6 is disposed) is integrally cut or cast by a machine. The blade angle at the entrance of the guide blade 6 is set according to the design specifications. In the test after manufacture, if the obtained pump characteristics were not satisfied, the impeller 3 had to be remodeled or the port at the entrance of the guide blade 6 had to be adjusted, and the correction was extremely troublesome and costly. .

[0006] In view of the above prior art, the present invention provides a specification that requires pump performance characteristics (relationship between flow rate and head, maximum pump efficiency point) for the same impeller simply by performing a simple replacement operation. It is an object to provide a guide vane that can be adapted.

[0007]

According to a construction of the present invention, which solves the above-mentioned problems, in a mixed flow pump, a portion of the guide blade upstream from the top of the guide blade is replaced with a replaceable partial guide blade. The partial guide vane to be mounted has a blade inlet angle and an effective passage width that can adapt the pump performance to required specifications from a plurality of types of partial guide vanes having different blade entrance angles and effective passage widths. It is characterized in that it is selectively mounted in a shape.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. In addition, parts performing the same functions as those of the conventional technology are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 shows a main part of a guide blade according to an embodiment of the present invention. FIG. 1 (a) shows a meridional plane shape, and FIG. 1 (b) shows a state viewed from the front. I have. FIG. 2 shows the relationship between the impeller 3 and the guide blade 6.
As shown in both figures, the part of the guide blade 6 upstream from the top of the guide blade is a replaceable partial guide blade 6a. The partial guide blade 6a is accurately positioned at the boss-side spigot portion 10 and is fixed with a bolt. By properly fixing the casing to the casing, a force acting in the rotational direction prevents the partial guide vanes 6a and the guide vanes (non-replacement portions) 6 from shifting in the rotational direction.

The guide vanes 6a can be replaced with respect to the guide vanes (non-replacement portions) 6. As shown in FIG. 3 (corresponding to the section AA in FIG. 1), a plurality of types of partial guide blades 6a having different blade entrance angles 11 and effective passage widths (ports) 12 are prepared. Then, a partial blade 6a having an optimum blade inlet angle 11 and an effective passage width 12 for adjusting the pump performance to required specifications is selected and attached to the guide blade (non-replacement portion) 6.

In FIG. 3, a broken line indicates a profile in which the blade entrance angle 11 and the port 12 are large, and a solid line indicates a profile in which the blade entrance angle 11 and the port 12 are small. As shown in FIG. 3, when the blade inlet angle 11 is large, the port 12 is also large, so that the flow condition is optimal on the large flow side, and the performance on the large flow side is improved.
Conversely, when the blade inlet angle 11 is small, the port 12 is also small, so that the optimal flow condition is obtained on the small flow rate side.
The performance on the small flow rate side is improved. Therefore, when the pump characteristics obtained in the test after manufacture do not satisfy the specifications, the partial guide blade 6a having the blade inlet angle 11 and the port 12 that provides the highest performance in the required flow rate range is provided. By simply replacing, good flow conditions can be obtained.

[0012]

As described above in detail with the embodiments, according to the present invention, in the mixed flow pump, the part of the guide blades upstream from the top of the guide blade is replaced with a replaceable partial guide blade. In addition, the partial guide vanes to be mounted are selected from a plurality of types of partial guide vanes having different blade entrance angles and effective passage widths, and are capable of adjusting the pump performance to required specifications. A configuration having a shape having the following is selected and attached.

In the present invention, the plurality of types of partial guide blades have different blade entrance angles and effective passage widths (ports), and when the blade entrance angle is large, the port becomes large, and the same impeller is used. The performance on the larger flow rate side is improved. On the other hand, when the blade entrance angle is small, the port becomes small, and the performance on the smaller flow rate side is improved. Which flow range should have the best performance depends on the required specifications.

In other words, according to the present invention, in the guide vanes having the same meridional plane shape, several types of partial guide vanes are prepared separately from the upper part of the guide vane upper part as the partial guide vanes and can be replaced. The partial guide vanes prepared here have different vane entrance angles and effective passage widths (ports). By replacing these several types of partial guide blades, it is possible to adapt the pump performance characteristics (the relationship between the flow rate and the head, the maximum pump efficiency point) to the required specifications for the same impeller. Therefore, rather than improving the profile of the blade with only one guide blade,
Work and time are greatly reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a guide blade according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a main part of a mixed flow pump including a guide blade according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a relationship between a blade entrance angle and an effective passage width (port).

FIG. 4 is a configuration diagram showing a conventional mixed flow pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main shaft 2 Guide vane boss 3 Impeller 4 Casing 5 Suction bellmouth 6 Guide vane 6a Partial guide vane 7 Guide vane boss 10 Inlay part 11 Blade entrance angle 12 Effective passage width (port)

Claims (1)

[Claims] In a mixed flow pump, a portion of a guide blade upstream from a top of the guide blade is replaced with a replaceable partial guide blade, and the mounted partial guide blade is configured to have a blade entrance angle and an effective passage width. Are selected and mounted from among a plurality of types of partial guide blades having different blade inlet angles and effective passage widths that can match pump performance to required specifications. Guide vane.