JPH116133A - Intermediate girder mounting device for bar screen for dust remover - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the water flow resistance of an intermediate girder mounting device for a bar screen for a dust remover. SOLUTION: An intermediate girder 1 fixed to a downstream side of a bar 2 of a dust cleaner bar screen is a hollow body having a wing-shaped cross section, and is fixed through a guide pipe 4 at a horizontal center portion thereof. I do.
Further, an eyebolt 6A is formed by fixing the tip of a bolt to a distance space 5 for maintaining the distance between the bar-2, and the eyebolt 6A is inserted into the guide pipe 4 to connect the bar-2 with the intermediate receiving beam 1. Because they are combined, they not only reduce water flow resistance, but also do not catch dust.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intermediate girder mounting device for a bar screen for a dust remover.

[0002]

2. Description of the Related Art In general, a bar screen for a dust remover is formed by arranging flat steel bars vertically at regular intervals to form a lattice shape. Therefore, each screen bar has a rectangular cross section. For the purpose of lowering the water flow resistance, there are also those having a circular cross section (pipe body) and those having round ends at flat steel ends (for example, see Japanese Utility Model Publication No. 60-33142 and Japanese Patent Application Laid-Open No. Hei 7-113210).

On the other hand, in such a bar screen, an intermediate girder for supporting the arranged screen bars on the downstream side is provided.
The bar screen is reinforced. For this purpose, an H-shaped steel consisting of a flange and a web is generally used, and a T-shaped steel is rarely used.
-23777).

[0004] The intermediate girder using such H-section steel or T-section steel is convenient for assembling and joining because of the presence of a flange, and is inexpensive in material, but does not take into consideration the water flow resistance. .

[0005] The inventors of the present invention have intensively analyzed the water flow resistance in the intermediate girder, that is, the head loss caused by the intermediate girder in the waterway, and have attempted development.

That is, as shown in the conventional example in FIG. 3, an analysis was conducted on an intermediate girder 54 using an H-shaped steel comprising two flanges 51 and 52 and a web 53 connecting these flanges. Numeral 55 indicates a screen bar having a rectangular cross section, numeral 56 indicates a fixing bolt, and numeral 57 indicates a distance speed.

First, a general theory will be described. When a screen (grid) is installed in the waterway, the head loss h
Is, as is well known,

[0008]

(Equation 1)

## EQU1 ## Here, f = screen bar
V = flow velocity g = acceleration of gravity This f is the well-known Kirschmer's empirical formula.

[0010]

(Equation 2)

## EQU1 ## Here, s = screen bar
B = screen bar spacing θ = inclination angle of the entire lattice β = shape factor, which is determined by the cross-sectional shape of the screen bar.

Therefore, the head loss h occurring before and after the screen is proportional to the shape factor β of the screen bar 55. If the cross-sectional shape of the screen bar 55 is an airfoil, the flat steel with a rectangular cross section is only 0.17 compared to 3.4.

Therefore, it is said that a screen bar having an airfoil cross section can reduce the head loss by a ratio of 1: 3.3 as compared with a screen bar having a rectangular cross section, according to common sense. I have.

However, the above analysis is based on the screen bar, and is not performed on the intermediate receiving beam 54. That is, as shown in FIG. 3, in the middle receiving girder 54 using the H-section steel in the water channel flowing as indicated by the arrow, particularly when the flow velocity v of the water channel becomes large (for example, 4 m ³ / sec for water intake).
c) Four vortices 58, 58... are generated at both ends of the two flanges 51, 52 as shown in FIG.
4 causes a head loss above the projection height c.

Accordingly, the present applicant has made and made a proposal to reduce the head loss as much as possible by using an intermediate girder 30 as shown in FIG. FIG. 2A is an overall view, and FIG.
FIG. 2A is a horizontal cross-sectional main part view of FIG.

That is, the screen bar 31 shown in FIG.
The bar screen for the dust remover provided with
m, the length of the screen bar 31 is about 4
The dimensions are 000 mm, width 75 mm and thickness 9 mm.

Further, a large number of screen bars 31, 31,...
Are erected at a distance of about 50 mm by SUS destance speeds 32, 32... Of course, a penetrating rod is inserted through these distance teeth 32.

Downstream of these screen bars 31, two upper and lower intermediate receiving girders 30, 30 are provided horizontally.

The intermediate girder 30 is formed to have a particularly circular or elliptical cross section (a modification of a normal circular pipe) to reduce the water flow resistance.

[0020]

However, the bracket 33 for connecting the intermediate girder 30 having the elliptical cross section to the screen bar 31 allows the intermediate girder 30 having the elliptical cross section having a small water flow resistance to be provided. There was a problem of increasing water flow resistance.

That is, the bracket 33 is provided with the angle iron 3
The long part 34a of the angle iron 34 is welded to the peripheral surface of the intermediate girder 30, and the short part 34b is fixed to a detent speed by a bolt 35 whose tip end is welded to an eyebolt. doing.

Therefore, there is a problem that the flow is disturbed by the short portion 34b and the bolt 35, and the dust is easily caught, and as a result, the water flow resistance is increased.

Accordingly, the present invention has as its main object to solve such a problem, and has as its secondary object to firmly configure an intermediate receiving girder.

[0024]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is as follows. 1) An intermediate girder fixed to a downstream side of a screen bar of a dust cleaner bar screen. The receiving girder is a hollow body formed by an arc, and a bolt for connecting the screen bar and the receiving girder is inserted through a horizontal center portion thereof. -In the intermediate girder mounting device, and 2)
2. A bar screen for a dust remover according to claim 1, wherein a guide pipe is penetrated and fixed to a horizontal center portion of the hollow body, and a bolt for connecting said screen bar and a receiving girder is inserted into said guide pipe. In the intermediate girder mounting device.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in the accompanying drawings.

FIG. 1 is a sectional view of a main part of an embodiment of the present invention (corresponding to a main part of FIG. 2A of a conventional example). The used dust collector bur screen is conveniently used in the seawater intake channel of a hydro / nuclear power plant, and this scribe bar-2 has the same dimensions as the scribe bar 31 shown in FIG. I have.

In FIG. 1, an intermediate girder 1 is a wing composed of a large-diameter portion 1a and a small-diameter portion 1b which are formed by mass-producing a steel circular pipe body into a slightly flat shape by a molding method for deforming the entire pipe. A through hole 3 is opened by a drill along the center of the horizontal shape (in a direction substantially orthogonal to the screen bar 2), and a SUS guide pipe 4 is welded to the through hole 3. I have.

The molding method for deforming the entire pipe is as follows.
The outer periphery of the mass-produced pipe body is squeezed with a plurality of roller groups,
By passing these roller groups through several stages, it is possible to easily form the roller group and to provide an inexpensive intermediate girder 1. Of course,
You may shape | mold with a die and a punch.

On the other hand, between each of a large number of screen bars made of steel plates (both ends may be round), there are interposed SUS destain speeds 5.
The eyebolt 6A is formed by welding the tip of a long SUS bolt 6 to one of them. That is, this bolt 6
Connects the screen bar-2 and the intermediate receiving beam 1.

The eyebolt 6A is connected to the guide pipe 4
, A nut 8 is screwed onto a screw 7 of the projecting portion, and the large diameter portion 1a is brought into contact with the screen bar -2 to join the intermediate girder 1.

Therefore, since the intermediate receiving beam 1 does not have a bracket for generating water flow resistance as in the prior art, the water flow resistance is reduced, and the head loss is reduced.

In addition, an eyebolt 6A is attached to the guide pipe 4.
, The assembly connection between the screen bar 2 and the intermediate receiving girder 1 is facilitated. Further, even if the eye bolt 6A is tightened with the nut 8 and the tightening force is increased, the airfoil is supported by the support of the guide pipe 4. The buckling deformation of the cross section is prevented, and the bolt 6 penetrates the major axis of the airfoil cross section, that is, the horizontal center of the intermediate girder 1. Does not occur. Of course, there is no cost increase because the structure is simple and the production is easy.

The intermediate girder 1 is not limited to an airfoil section, but may be a hollow ellipse or a circle. In short, it may be a hollow body formed by an arc.

[0034]

According to the present invention, since the intermediate girder is a hollow body formed by an arc, it is possible to lower the water flow resistance and, of course, to provide the hollow body with a screen bar and an intermediate girder. Since the connecting bolts are inserted, the connecting device does not catch dust that is difficult to remove, and the head loss is reduced, so that no water resistance is generated. In addition, since the bolt is inserted through the horizontal center portion of the hollow body, there is no trouble in positioning and connecting the intermediate girder due to eccentricity or the like.

According to the second aspect of the present invention, the hollow body is buckled and deformed due to excessive tightening of the bolt because the guide pipe is fixed through the guide pipe.

Since the water flow resistance is reduced in the bar screen which originally has a high water flow resistance, that is, the water flow resistance is not generated, an unexpected situation, for example, a shortage of an intended water intake amount occurs, -It does not cause an abnormal water level difference before and after the screen, and further improves the reliability of the dust screen.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an embodiment of the present invention.

FIG. 2 is a conventional example.

FIG. 3 is a sectional view of a main part of another conventional example.

[Explanation of symbols]

1 ... Intermediate girder, 2 ... Screen bar, 4 ... Guide pipe, 6 ... Bolt

Claims (2)

[Claims] An intermediate girder fixed to a downstream side of a screen bar of a dust cleaner bar screen, wherein the girder is a hollow body formed by an arc and has a horizontal center portion. An intermediate girder mounting device for a bar screen for a dust remover, wherein a bolt for connecting the screen bar and the girder is inserted. 2. A dust collector according to claim 1, wherein a guide pipe is penetrated and fixed to a horizontal center portion of the hollow body, and a bolt for connecting said screen bar and a receiving beam is inserted into said guide pipe. Intermediate girder mounting device for bar screen.