JPH0615814B2 - Diffuser for silencer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a diffuser in a muffler for discharging steam of a boiler for thermal power generation. However, not only the boiler for thermal power generation but also a turbine plant for thermal power generation, It can also be applied to mufflers for vapor discharge in chemical plants.

[Conventional technology]

2 and 3 show an example of installation of a silencer for discharging steam used in a thermal power plant.

Fig. 2 shows an installation example of a silencer for a safety valve for a boiler, and Fig. 3 shows an installation example of a silencer for a blow flash tank. In this way, the steam flowing out from the safety valve or the blow flash tank passes through the exhaust pipe and flows into the muffler to be reduced in noise.

Further, FIG. 4 shows a schematic structure of a silencer for vapor emission. As shown in the figure, a diffuser 08 having a perforated plate is attached to the inlet of the silencer for the purpose of protecting the sound absorbing material against strong steam flow and rectifying the steam flow.

2 to 4, 01 is a steam mother pipe, 02 is a safety valve, 03 is an elbow joint, 04 is an exhaust pipe, 05 is a silencer, 06 is a blow flash tank, 07 is a silencer body, 08 is The diffuser (perforated plate), 09 is a sound absorbing panel.

[Problems to be solved by the invention]

In the conventional diffuser as described above, the steam flow after exiting the perforated plate suddenly expands and becomes a choke flow accompanied by a shock wave to generate a strong sound. In this case, the muffler needs to reduce both the sound generated from the safety valve and the flash tank and the sound generated from the diffuser, but the amount of sound absorbing material for reducing the sound generated from the diffuser increases, and as a result, However, there is a problem that the silencer becomes large and the weight increases.

[Means for solving problems]

The collision force due to the flow of steam is received by the buffer plate that is perpendicular to the flow,
A porous metal is provided around a cylindrical porous plate parallel to the flow, and the porous metal is fixed by a birdcage-shaped holding plate.

As a result, the choke flow having strong turbulence flowing out from the perforated plate is gradually expanded.

[Work]

The steam generated from the safety valve and blow flash tank is
After colliding with the buffer plate, the flow direction is changed by 90 °, and it flows out as a jet from the cylindrical porous plate. At that time, the porous metal provided around the perforated plate gradually expands, and the sound generated from the diffuser is reduced.

〔Example〕

An exhaust pipe 2 is connected to the silencer 1. At the inlet of the muffler 1, a buffer plate 3 arranged at a position to block the flow of steam
And a cylindrical perforated plate 4 which is integrated with this and is parallel to the flow of steam.
Is fixed.

Further, around the cylindrical perforated plate 4, a total of 16 porous metals 5 which are divided into two in the axial direction and eight in the circumferential direction are installed.

Further, the porous metal 5 is fixed in a birdcage shape by the upper receiving plate 6, the lower receiving plate 7 and the eight holding plates 8 so that it can be removed from the porous plate 4.

In such a device, the diffuser 10 is connected from the exhaust pipe 2.
The steam flowing into the perforated plate 4 once collides with the buffer plate 3 and then the perforated plate 4
More outflow.

When the steam passes through the perforated plate 4, it becomes a choked flow having a strong turbulence, but by passing through the porous metal 5 arranged immediately after the perforated plate 4, the flow is finely divided into particles and gradually expands, The sound generated from the diffuser 10 can be reduced.

Also, the steam collides with the collision plate 3 and changes its direction,
The force acting on the porous metal 5 is reduced, and further, the porous plate 4
Since the steam flows out radially from, the outflow reaction forces are canceled out on the circumference, resulting in an equilibrium state.

As a result, the porous metal can be easily supported, a sufficient opening ratio can be obtained on the outlet side of the porous metal, the choke flow velocity can be reduced, and the generated noise can be reduced.

As the material of the porous metal 5, foam metal, metal wool, sintered metal, wire mesh metal (mesh) or the like is used.

As the shape of the porous metal 5, in addition to the above-described divided structure, an integrally molded type, a disc stack type, or a multi-cylindrical type can be adopted. When the divided structure is adopted, a commercially available sheet-shaped porous metal 5 is used. It is possible to easily process a fine metal according to the curvature of the diffuser 10, and to manufacture an inexpensive porous metal 5.

〔The invention's effect〕

A conventional silencer diffuser produces a jet of strong turbulence when steam passes through a perforated plate, producing a strong sound.However, a porous metal is placed immediately after the perforated plate, and the diffuser expands by gradually expanding it. The noise generated can be reduced and the silencer can be miniaturized.

In addition, the porous metal can be easily attached to and detached from the tiffuser, and even if the porous metal becomes incompatible with wear or clogging, it can be replaced with a new one to exhibit stable performance.

[Brief description of drawings]

1 (a) and 1 (b) are a plan view and a sectional view of a silencer diffuser as an embodiment of the present invention, FIGS. 2 and 3 are attachment state diagrams of the silencer, and FIG. 4 is a conventional view. It is a conceptual diagram of a silencer and a diffuser. 1 ... Silencer, 2 ... Exhaust pipe 3 ... Buffer plate, 4 ... Perforated plate 5 ... Porous metal, 10 ... Diffuser

Claims (1)

[Claims] 1. A silencer in which a pipe wall of an exhaust pipe protruding into a silencer is formed of a perforated plate and the pipe end is closed, and a cylindrical porous metal is arranged around the perforated plate, The metal is fixed in a birdcage shape by a plurality of pressing plates in the ridge direction and a receiving plate in the direction perpendicular to the axis, and the jet flowing out from the perforated plate is gradually expanded in the radial direction in the porous metal to generate the sound generated by the jet. A diffuser for a silencer characterized by being reduced.