JP2003042402A - Boiler provided with sound insulation wall in air- introducing path - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boiler capable of reducing the noise generated due to the leak of the combustion sound generated by combustion outside the boiler. SOLUTION: In a boiler having a blower 2 delivering the air taken in from an air intake 4 into a combustion chamber 10 and a burner 7 feeding fuel to burn and performing combustion while delivering combustion air by the blower 2, a sound insulation wall 11 is provided at the central axis part of air flow in the air-introducing path 14 connecting the blower 2 with the air intake 4, and a sound absorbing material 1 is provided on the inner wall surface of the air introducing path 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler provided with a sound insulation wall in an air introduction passage.

[0002]

2. Description of the Related Art In the case of a boiler that has a blower for sending combustion air into a combustion chamber and a burner for burning flames in the combustion chamber, and forcibly sends fuel and combustion air for combustion, the combustion chamber is used during combustion. Makes a loud burning noise. The combustion chamber is connected to the outside through the exhaust passage, and the combustion noise goes out through the exhaust passage together with the exhaust gas. Therefore, a noise is leaked to the outside by installing a silencer in the exhaust passage. However, the combustion noise of boilers has become louder due to the recent miniaturization and higher load, and on the other hand, lower noise than ever has been demanded due to heightened environmental awareness, and the extension of conventional noise reduction technology is not enough. .

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a boiler capable of reducing the noise generated when the combustion noise generated by combustion leaks to the outside of the boiler.

[0004]

The invention according to claim 1 has a blower for feeding air taken in from an air intake port into a combustion chamber, and a burner for supplying fuel for combustion, and the combustion air is blown by the blower. In a boiler that combusts while being fed, a sound insulation wall is provided on a central axis portion of an air flow in an air introduction path connecting a blower and an air intake port, and a sound absorbing material is provided on an inner wall surface of the air introduction path.

According to a second aspect of the present invention, in the boiler provided with a sound insulation wall in the air introduction passage, the sound insulation wall has a cylindrical shape in which a tip of the air flow upstream side is closed and an air flow downstream side is opened. It is characterized in that it has a shape in which air circulation holes are opened in the peripheral wall surface of the cylinder side surface.

[0006]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a boiler embodying the present invention, and FIG. 2 is a sectional perspective view of a sound insulating wall portion in one embodiment. The boiler is provided with a combustion chamber 10 at the center and burns inside the combustion chamber by a burner 7 provided above the combustion chamber. A wind box 5 for adjusting the flow of combustion air is provided above the burner 7, and a ventilation duct 6 for passing the combustion air is connected to the wind box 5, and the other end side of the ventilation duct 6 takes in air. The blower 2 that sends the air taken in by the mouth 4 to the blower duct 6 is connected. The combustion chamber 10 is a substantially cylindrical combustion chamber in which the periphery is surrounded by a large number of water pipes 3. By burning in the combustion chamber 10, the surrounding water pipes are heated to generate steam.
An exhaust passage 8 is connected to the combustion chamber 10, and an exhaust passage silencer 9 is provided in the middle of the exhaust passage 8.
The other end of is open to the atmosphere.

Combustion air is supplied into the combustion chamber 10 through the air intake 4, the blower 2, the air duct 6, and the wind box 5, and is provided in the middle of the air introduction path 14 connecting the air intake 4 and the blower 2. A sound insulation wall 11 is provided to shield the combustion sound generated in the combustion chamber 10. The sound insulation wall 11 closes a part of the air flow path with the air introduction passage 14.
Is provided in the central portion of the air introduction path so as to include the central axis of the air flow in the air introduction path. Since the air introduction path 14 must pass the combustion air, the sound insulation wall 11 closes the air introduction path only in the central portion, and the sound insulation wall 11 in FIG. 2 has an annular air circulation passage around it. It has a disk shape. A sound absorbing material 1 for absorbing combustion sound is provided on the wall surface of the air introduction path that is in contact with the periphery of the portion where the sound insulation wall 11 is installed.

The boiler is operated by supplying fuel and combustion air to the combustion chamber 10 and burning it in the combustion chamber. Combustion air is supplied by operating the blower 2. When the blower 2 is operated, the blower 2 sucks air from the air intake port 4, pressurizes it in the blower section, and sends it to the combustion chamber 10. Sound insulation wall 1 in the air introduction path connecting air intake 4 and blower 2
1 is provided, but since a passage for air circulation is opened around the sound insulation wall 11, suction of air can be performed from an annular passage around the sound insulation wall, and air entering from the air intake port 4 is The flow is toward the blower 2 through the passage around the sound insulation wall.

The combustion air pressurized by the blower 2 and sent into the combustion chamber 10 mixes with the fuel injected from the burner 7 to form a flame. By burning the flame, the water pipe 3 around the combustion chamber is heated, and the can water in the water pipe is heated to generate steam. The exhaust gas generated by the combustion of the flame is discharged into the atmosphere through the exhaust passage 8. In the case of a boiler that combusts by forcibly sending combustion air, a large combustion noise is generated in the combustion chamber during combustion. The combustion noise that takes the same flow as the exhaust gas and goes out from the combustion chamber 10 through the exhaust passage 8 can be reduced by the exhaust passage silencer 9 provided in the middle of the exhaust passage 8, The noise leaked to the outside is small.

The combustion noise transmitted in the same direction as the exhaust gas flow can be reduced by the exhaust passage silencer 9, but the combustion noise transmitted in the opposite direction to the combustion air flow and emitted from the air intake port 4 is Even if the exhaust passage silencer 9 is provided, the effect of noise reduction cannot be obtained. The combustion sound that travels in the direction that traces back the combustion air flow propagates to the air intake port 4 through the wind box 5, the blower duct 6, and the blower 2.

Since the sound insulation wall 11 has a shape having a surface perpendicular to the propagation direction of the combustion sound and is provided in the central portion of the air introduction path, the combustion sound that has propagated collides with the sound insulation wall 11 or the sound insulation wall 11. It will travel radially so as to avoid 11. The sound absorbing material 1 is provided at the tip radially extending from the sound insulation wall 11, and when the combustion sound reaches the sound absorbing material 1, the sound absorbing material 1 absorbs the energy of the combustion sound, so that the energy of the combustion sound becomes small. Therefore, the combustion noise emitted from the air intake port 4 is reduced, and the noise leaked from the boiler can be suppressed to a low level.

Since it is considered that the combustion noise generated in the combustion chamber goes out through the exhaust passage 11 together with the exhaust gas, a noise countermeasure has been taken by providing an exhaust passage silencer 12 in the exhaust passage 11. However, as a result of research, it was confirmed that not only the combustion noise was emitted from the exhaust passage 11, but also the combustion noise was transmitted in the direction opposite to the air flow and was emitted from the intake port of the combustion air. Even if the exhaust passage silencer 12 is provided in the exhaust passage 11, the combustion noise emitted from the intake port of the combustion air cannot be reduced, but the sound insulation wall 11 is provided in the air introduction passage.
By providing the sound absorbing material 1 on the wall surface of the air introduction path around the sound insulating wall 11, the combustion sound transmitted in the opposite direction to the air flow can be directed to the sound absorbing material 1, and the sound absorbing material Since the energy of is reduced, it is possible to reduce the combustion noise that goes out from the intake port of the combustion air.

Although the combustion sound has a peak at 300 to 500 Hz, a wind noise having a peak at 800 to 1200 Hz is also generated in the portion where the combustion air flows. Since the frequency characteristics of combustion noise and wind noise are different, it is necessary to provide a sound absorbing material corresponding to the combustion noise in order to enhance the effect of reducing the combustion noise.

FIG. 3 is a sectional perspective view of a sound insulation wall portion in another embodiment of the present invention. In the embodiment of FIG. 3, the sound insulation wall 11
Although the parts are different from those in the above-mentioned embodiment, the same boiler main body as in FIG. 1 is used as it is, and the description of the boiler main body has been given earlier, so that the description of the overlapping portions will be omitted.

The sound insulation wall 11 of FIG. 3 has a cylindrical shape in which the upstream side of the air flow is closed and the downstream side of the air flow is open. The sound insulation wall 11 is provided in the central portion of the air introduction passage 14 so as to include the central portion of the air flow in the air introduction passage 14, and the air circulation hole 12 is provided in the peripheral wall portion of the cylindrical side surface. In the portion where the sound insulating wall 11 is provided, the sound absorbing material 1 is provided on the wall surface of the air introduction path, and an air circulation passage is opened between the sound insulating wall 11 and the sound absorbing material 1. On the downstream side of the air flow hole 12 in the air flow direction, in order to close the air flow passage, a sound insulation wall 11 is provided with a closing wall 13 that closes the wall surface of the air introduction path around the sound insulation wall 11, and the combustion noise of the sound insulation wall 11 Make sure that it does not pass through the surroundings and go directly to the air intake port 4.

When the blower 2 is operated to operate the boiler, the blower 2 sucks air from the air circulation holes 12 of the sound absorbing material 1. Therefore, the combustion air that has entered from the air intake port 4 is not covered by the sound insulation wall. It enters into the cylinder from the air circulation hole 12 of 11 and goes toward the blower 2 through the inside of the cylinder. Combustion chamber 10
When combustion is performed inside, combustion noise is generated, and a part of the combustion noise is transmitted to the air intake port 4. When the sound insulation wall 11 has a cylindrical shape and the combustion air enters into the cylinder through the air circulation hole 12 of the sound insulation wall 11, the combustion sound transmitted in the direction opposite to the air flow is the air flow opposite to the air flow. Since there is no way other than through the holes 12 to the outside of the cylinder, the combustion noise passes through the air circulation holes 12 and radially exits from the air circulation holes 12 in the circumferential direction.

Since the sound absorbing material 1 for absorbing the combustion sound is provided around the sound insulation wall 11, the combustion sound emitted from the air circulation hole 12 advances toward the sound absorbing material 1 and the combustion sound is surely produced. Reach sound absorbing material 1. When the sound absorbing material 1 is reached, the sound absorbing material 1
Since the energy of the combustion sound is absorbed by, the combustion sound becomes smaller. Therefore, the combustion noise emitted from the air intake port 4 can be reduced, and the noise of the boiler is reduced.
When the sound insulation wall 11 has a cylindrical shape and the combustion sound is emitted from the air circulation holes 12 radially provided on the side surface of the cylinder, the combustion sound always advances toward the sound absorbing material 1 provided around the sound insulation wall 11. Combustion noise can be efficiently reduced by the material 1.

[0018]

By implementing the present invention, the combustion noise leaking out of the boiler is reduced, and the noise of the boiler can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a boiler embodying the present invention.

FIG. 2 is a cross-sectional perspective view of a sound insulation wall portion in one embodiment.

FIG. 3 is a sectional perspective view of a sound insulating wall portion in another embodiment.

[Explanation of symbols]

1 sound absorbing material 2 blower 3 water tubes 4 Air intake port 5 wind box 6 air duct 7 burners 8 exhaust passage 9 Exhaust passage silencer 10 Combustion chamber 11 sound insulation walls 12 Air circulation holes 13 closed wall 14 Air introduction path

Claims (2)

[Claims] 1. A boiler having an air blower for feeding air taken in from an air intake port into a combustion chamber and a burner for supplying fuel for combustion, and a boiler for performing combustion while feeding combustion air by the blower, and the blower and the air intake port A boiler provided with a sound insulation wall in the air flow center axis part in the air introduction path that connects the air introduction path and a sound absorbing material provided on the inner wall surface of the air introduction path. 2. The boiler having a sound insulation wall provided in the air introduction passage according to claim 1, wherein the sound insulation wall has a cylindrical shape in which a front end on the upstream side of the air flow is closed and a downstream side on the air flow is opened. A boiler having a sound insulation wall in an air introduction path, which is characterized in that an air circulation hole is formed in a peripheral wall surface.