JPH02223699A - Impeller container-incorporating type pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an impeller-container built-in pump used in nuclear power plants, chemical plants, and the like.

(Prior Art) A pump with an impeller built into a container will be described below using an example of a pump built into a reactor pressure vessel.

FIG. 4 is a sectional view showing the relative positional relationship of a conventional example in which a pump is incorporated into a reactor pressure vessel.

That is, a plurality of pumps P are installed in the lower part of the reactor pressure vessel 2.
are arranged in a circle. The pump P is arranged to generate a fluid flow as shown by an arrow between the reactor pressure vessel 2 and the passage plate II, and force the fluid to flow into the reactor core 13.

FIG. 5 is a partially side sectional view showing a state in which the pump P shown in FIG. 4 is attached. In FIG. 5, the impeller 1 is disposed so as to pass through a baffle plate 12 formed at the lower part of a channel plate 11 in a reactor pressure vessel 2. As shown in FIG. A pump shaft 3 connected to the impeller 1 projects to the outside of the reactor pressure vessel 2 through a nozzle 4 formed in the reactor pressure vessel 2, and is connected to an electric motor 5. The lower end of the center hole of the stationary blade 6 surrounding the impeller 1 has a stepped portion 6 facing inward.
a is formed. A sleeve 7 surrounding the pump shaft 1 is fitted into the center hole of the stationary vane 6'. The upper end of this sleeve 7 is formed with an outwardly stepped portion 7a.
The stepped portion 7a of this sleeve 7 is the stepped portion 6 of the stationary blade 6.
The relationship is such that it sits on top of a.

The lower part of the sleeve 7 projects to the outside of the reactor pressure vessel 2 . A thread is threaded on the outer surface of the lower end of the sleeve 7, and a nut 8 is disposed on this threaded portion. and the stationary wing 6. A key 14 is located between the sleeve 7 and the nozzle 4.
is installed.

Here, FIG. 6 shows an enlarged longitudinal section near the key 14, and FIG. 7 shows a sectional view taken along the line B--B in FIG. 6. Misalignment between the center axis of the stationary blade 6 and the center axis of the nozzle 4 does not cause any practical problems by providing a fitting structure between the stationary blade 6 and the sleeve 7 and between the sleeve 7 and the nozzle 4, respectively. is kept at a small value. The key 14 is provided to prevent the stationary blade 6 from rotating due to the rotational torque received from the rotating impeller 1 via running water. Furthermore, impeller 1
The center axis of rotation of the pump shaft 3 is set to coincide with the center axis of the hole of the nozzle 4 by adjusting a bearing in the electric motor 5.

(Problems to be Solved by the Invention) When performing maintenance and inspection of a pump with a built-in impeller container as described above, it is necessary to disassemble and assemble each component of the pump. Problems related to disassembly and assembly of the sleeve 7 and key 14 will be described below. First, we will discuss the issues involved in disassembly work. After the impeller 1 is removed, the nut 8 is removed and the stationary blade 6, sleeve 7, and key 14 are pulled upward as a unit.

However, since the sleeve 7 and the nozzle 4 and the key 14 and the key groove of the nozzle 4 have a fitting structure, the gaps are extremely small. There was a possibility of galling occurring between the keyway and the keyway. In this case, the location where the galling occurred is close to the reactor and in a radioactively contaminated environment, making it difficult for people to approach with tools and potentially making disassembly difficult.

Next, we will discuss issues in assembly work. Contrary to the disassembly work mentioned above, it is stationary! 6. Suspend the sleeve 7 and key 14 integrally from above with a wire or the like and insert it into the hole of the nozzle 4. However, as mentioned above, between the sleeve 7 and the nozzle 4 and between the key 14 and the nozzle 4,
The gaps between the key grooves of the sleeve 7 and the nozzle 4 or the key 14 are extremely small due to the fitting structure.
There was a possibility that it would get caught between the key groove of the nozzle 4 and the nozzle 4, and the insertion would not be carried out smoothly. In that case, the part where the snag occurred is close to the nuclear reactor and in a radioactively contaminated environment, making it difficult for people to access and potentially making assembly difficult.

The present invention has been made in order to solve the above problems.The stationary blade, the sleeve, and the key are integrated, so that it is easy to remove from the nozzle and attach to the nozzle. An object of the present invention is to provide a pump with a built-in impeller container that is less likely to cause such problems.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, in the present invention, stationary blades surrounding an impeller are disposed inside a container, and an electric motor for driving the impeller is provided outside the container. In the pump with a built-in impeller container, at least three protrusions are formed on the outer side of the stationary blade, and a structural member is provided in the container to abut each of the protrusions. A pump with a built-in impeller container is provided.

(Function) In the impeller container built-in pump configured as described above, at least three protrusions formed on the outer periphery of the stationary blade provided inside the container are fixed in the container. When the member contacts the rotating surface of the impeller, the position of the center axis of the stationary blade is determined, and the stationary blade transfers the rotational torque received from the impeller through the flowing water to the outer circumference of the stationary blade. Rotation of the stationary wing itself can be prevented by transmitting the signal to a structural member fixed inside the container through a protrusion provided in the container.

(Example) A pump with a built-in impeller container according to an example of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a sectional view showing an entire embodiment of the present invention.

It should be noted that the same components as those in the conventional example shown in FIG. 5 are designated by the same reference numerals.

In FIG. 1, an impeller 1 is placed inside a reactor pressure vessel 2. In FIG. The horn shaft 3 protrudes outside the reactor pressure vessel 2 through a nozzle 4 and is connected to an electric motor 5. The stationary blade 6 is disposed close to the lower side of the impeller 1 inside the reactor pressure vessel 2 . The lower end of the hole at the center of the stationary blade 6 is formed with an inwardly stepped portion 6a. sleeve 7
is fitted into the center hole of the stationary blade 6. The upper end of the sleeve 7 is formed with an outwardly stepped portion 7a.
The stepped portion 7a of the stationary JI 6 rests on the stepped portion 6a at the lower end of the stationary JI 6. The sleeve 7 protrudes to the outside of the reactor pressure vessel 2 via a nozzle 4 that is fixed to the reactor pressure vessel 2 . A thread is threaded on the outer surface of the lower end of the sleeve 7, and a nut 8 is disposed on this threaded portion. Four protrusions 9 are provided radially on the outer periphery of the stationary blade 6. A lug IO is disposed in contact with each of the projections 9, and the lug IO is fixed on a baffle plate 12 that connects the reactor pressure vessel 2 and the channel plate 11.

2 is a sectional view taken along line EE in FIG. 1, and FIG. 3 is a sectional view taken along line AA in FIG.

As shown in FIGS. 2 and 3, the protrusions 9B, 9b, 9c and 9d provided on the outer periphery of the stationary blade 6 are equally distributed radially with respect to the central axis of the stationary blade 6. . These protrusions 9a, 9b, 9c, and 9d are located along the lug 10a in a plane passing through the rotation center axis of the impeller 1.
, 10b, 10c and lod, respectively. In such a state, the lags lOa, 10b, 10c, and lod are set in advance so that the size of the deviation between the central axis of the stationary blade 6 and the central axis of the impeller 1 is a value that does not cause problems in maintaining the function of the pump. Since this setting is made, the centering of the stationary blade 6 and the rotation stop shaft of the impeller 1 is completed when assembled in the state shown in FIGS. 2 and 3. In addition, the impeller 1 is rotated in the normal rotation direction,
That is, when the stationary blade 6 rotates in the direction of arrow C in FIG.
Lag lOa, 1 from a, 9b, 9c and 9d
Rotation of the stationary blade 6 itself is prevented by being transmitted to the baffle plate 12 via 0b, loc, and 10d.

As described above, in one embodiment of the present invention, the fitting structure between the sleeve 7 and the nozzle 4, which was necessary in the conventional example shown in FIG. The centering function between the stationary blade 6 and the rotation center axis of the impeller 1 and the stationary W6
It also has a rotation prevention function.

In the above embodiment, the case where the number of protrusions 9 provided on the outer periphery of the stationary blade 6 was four was explained, but if the number is three or more, they have the same function, so the number of protrusions is 4
Even cases other than these are included in the embodiments of the present invention.

〔Effect of the invention〕

According to the present invention, there is no need for a fitting structure between the sleeve and the nozzle as in the conventional example, as well as a key spanning the stationary blade, the sleeve and the nozzle, and between the sleeve and the nozzle or between the key and the keyway. There is no possibility of occurrence of events such as galling or sticking that would interfere with disassembly or assembly work. Therefore, the disassembly and assembly work of the impeller container built-in pump incorporated in the reactor pressure vessel can be carried out very easily and reliably. Similar effects can be expected in impeller container built-in pumps applied to chemical plant containers other than nuclear reactor pressure vessels.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the impeller container built-in pump according to the present invention, FIG. 2 is a view taken along the line E-E in FIG. 1, and FIG. 4 is a vertical cross-sectional view showing a conventional example of a reactor pressure vessel incorporating a pump, FIG. 5 is a vertical cross-sectional view showing a conventional example of a pump with built-in impeller vessel, and FIG. 5 is an enlarged vertical cross-sectional view showing the F portion in FIG. 5, and FIG. 7 is a cross-sectional view taken along the line B--B in FIG. 6. 1... Impeller 2... Reactor pressure vessel 3... Pump shaft 5... Electric motor 6... Stationary blade 9... Protrusion lO... Lug

Claims (1)

[Claims] In an impeller container built-in pump, in which a stationary blade surrounding an impeller is disposed inside the container, and an electric motor for driving the impeller is disposed outside the container, at least three A pump with a built-in impeller container, characterized in that a pump with a built-in impeller container is formed, and a structural member is provided in the container to abut each of the projections.