JPH0961089A - Cleaning device of tube body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning device of a tube body being excellent in a cleaning efficiency, without making the device very large. SOLUTION: Acoustic wave generating devices 4a-4d are provided in hollow parts 3a-3c formed between tube body groups 2 and the adjacent ones 2. The hollow parts 3a-3c including the tube body groups 2 are put in a resonance mode by acoustic waves emitted from the acoustic wave generating devices 4a-4d and thereby dust and the like sticking on tube bodies are removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a boiler, a combustion furnace,
The incinerator, the independent superheater, the independent economizer, various heat exchangers, and the cleaning device for pipes installed in various plants or various industrial equipment, especially the dust adhered to and accumulated on the wall surface of the pipes The present invention relates to a tube cleaning device that vibrates by a sound wave and removes it from a tube wall.

[0002]

2. Description of the Related Art FIG. 12 is a diagram showing a schematic configuration of a boiler. As shown in the figure, a rear heat transfer front wall 102 and a rear heat transfer side wall 10 installed at the rear of the furnace 101.
3, a rear heat transfer partition 104, and a rear heat transfer rear wall 105, a horizontal superheater 106, a horizontal evaporator 107, a economizer 108, etc. are provided at predetermined intervals in the flue. It is installed along the flow direction of combustion gas.

[0003] Each of the horizontal superheater 106 and the horizontal evaporator 10
7. In the economizer 108, a large number of heat transfer tubes 109 extend horizontally at narrow intervals, so that heat exchange between the high-temperature combustion gas G flowing in the flue and the fluid flowing in the heat transfer tubes 109 occurs. Done.

By the way, particularly in a pulverized coal burning boiler, the combustion gas G contains a large amount of combustion ash 110 and the like,
It adheres and accumulates on the wall surface of the heat transfer tube 109. FIG. 13 shows this state. When the combustion gas G passes between the heat transfer tubes 109, the Karman vortices 11 are generated in the wake of the heat transfer tubes 109.
1 is generated and the flow velocity decreases, so that combustion ash 110 adheres and deposits between the heat transfer tubes 109 and 109, and when the deposition proceeds, a bridge of the combustion ash 110 is formed between the heat transfer tubes 109. . Since the combustion ash having a relatively large particle size flows together with the combustion gas G, the adhesion and deposition on the heat transfer tube 109 is small, but the combustion ash 110 having a small particle size adheres and deposits on the heat transfer tube 109 as described above.

When the combustion ash 110 adheres to and accumulates on the wall in this way, the heat transfer performance of the heat transfer tube 109 deteriorates. Therefore, a soot blower (not shown) is activated periodically or as necessary to remove the combustion ash 110. The method of removing from the wall surface of the heat transfer tube 109 is adopted. However, as shown in the figure, the steam S ejected from the soot blower flows from the upper side to the lower side or from the lower side to the upper side along the row of the heat transfer tubes 109. It is not very effective in removing the combustion ash 110 accumulated between the lower heat transfer tubes 109.

Conventionally, in order to remove dust in the heat exchanger,
For example, a method as disclosed in Japanese Patent Publication No. 62-27375 is proposed. FIG. 14 is a diagram for explaining this dust removal method, in which a heat transfer tube group 122 is horizontally arranged in a casing 121, and a sound generator (siren) 123 is installed at the same height as the heat transfer tube group 122. The granular material 12 is installed on the upstream side of the casing 121.
A charging chute 125 for charging 4 is provided.

[0007] When the combustion ash adhering to and depositing on the heat transfer tube group 122 is removed by generating acoustic vibrations by the sound generator (siren) 123, the particle size is considerably larger than that of the combustion ash. Granular material 12 such as sand
4 from the chute 125 to add to the cleaning surface,
This is a method of promoting the falling of the combustion ash from the heat transfer tube 122 by substantially increasing the area subjected to vibration.

In addition to this, a sonic cleaning method as described in JP-A-55-500355 is also known. This method arranges at least two sound wave generators at a predetermined distance and controls a phase difference of a pressure wave emitted from another sound wave generator in relation to a pressure wave emitted from one sound wave generator. This is a method of generating an amplified pressure wave and concentrating the pressure wave on the surface to be cleaned.

[0009]

In the method of removing dust in the heat exchanger shown in FIG. 14, a mechanism for separating used particulate matter from dust and collecting it, and a circulation system for reusing the particulate matter. In addition, since the charged particulate matter may collect in the recesses and gaps inside the heat exchanger, it is also necessary to remove it, which makes the device larger and the work after dust removal complicated. Incurring higher costs.

Further, the sound generator 123 is used as the heat transfer tube group 12.
Since it is installed at the same height as 2, the sound wave emitted from the sound generator 123 immediately hits the heat transfer tube group 122 and is disturbed. Therefore, it is difficult to set the entire inside of the casing 121 to the resonance mode, and in order to reliably drop the combustion ash attached and accumulated on each heat transfer tube group 122 by vibration, the sound generating device 123 corresponding to each heat transfer tube group 122.
Need to be installed, and the number of installed sound generating devices 123 increases, which also leads to an increase in size and cost of the device.

Further, in the latter sonic cleaning method, it is possible to concentrate the amplified pressure wave on the surface to be cleaned and locally clean it, but for example, in a large space such as a flue of a boiler device, a large number of them can be cleaned. When a heat exchanger is installed and combustion ash is accumulated on the heat transfer tube group of each heat exchanger, the direction of the amplified pressure wave is changed to scan the surface to be cleaned with the pressure wave. Therefore, the scanning time is long and the work efficiency is low.

Further, the scanning of the pressure wave is performed by controlling the phase difference between two or more pressure waves. However, since the distance between the sound wave generator and the surface to be cleaned is sequentially changed depending on the scanning position, the position of the pressure wave is changed. It has problems such as very difficult phase difference control.

An object of the present invention is to effectively solve the above-mentioned drawbacks of the prior art, and to provide a tubular body cleaning device having good cleaning efficiency without increasing the size of the device.

[0014]

In order to achieve the above-mentioned object, the present invention installs a sound wave generator in a cavity formed between a tube group such as a heat transfer tube group and an adjacent tube group. Then, the cavity is set to a resonance mode by a sound wave emitted from the sound wave generator to remove dusts such as combustion ash adhering to the pipe body.

[0015]

For example, as shown in FIG. 14, when the sound wave oscillated from the sound wave generator is directly oscillated in the tube group, many small reflected sounds are generated from many tube bodies, and the energy of the oscillating sound wave advances. Decreases with direction. Further, the energy of the oscillating sound wave is reduced by the generation of the reflected wave from the wall having a large area.

In order to avoid these reductions, in the present invention, the frequency synchronized with the reflected sound (determined by the distance between the installation position of the sound wave generator and the wall) in the hollow portion (cavity) which has no tubular body and has little attenuation. Frequency) and oscillate wave energy and reflected wave energy are superposed to continuously retain a large resonance energy in the cavity, and thereafter,
By gradually expanding the amplified vibration energy in the tube group where many small reflected waves are generated and generating the same vibration as the entire tube group in the cavity, a large vibration also occurs in the space between the tube bodies. The dust generated and accumulated on the wall surface of the pipe can be effectively removed.

Further, the conventionally proposed granular material charging chute, the circulation system for reusing the granular material, the mechanism for separating the granular material from the dust that has fallen, etc. are not required, so that the apparatus becomes large in size, High costs are eliminated.

Since it is only necessary to adjust the frequency to bring the cavity including the tubular body into the resonance mode, the directivity is imparted to the sound wave by the phase difference control as has been conventionally proposed, and dusts are locally removed. The control is simpler than the method of removing, and dust is removed as a whole.

[0019]

Embodiments of the present invention will be described with reference to the drawings. FIG.
FIG. 2 is a front view of the rear heat transfer section of the boiler device, and FIG. 2 is a side view of the rear heat transfer section.

As shown in FIGS. 1 and 2, the heat transfer tube group 2 is arranged in several parts in the flue surrounded by the furnace wall 1, and the heat transfer tube group 2 is used for inspection between the individual heat transfer tube groups 2. A cavity 3 through which a person can pass is formed. The heat transfer tube group 2 corresponds to, for example, the above-mentioned horizontal superheater, horizontal evaporator, economizer, etc., and each heat transfer tube is arranged in the horizontal direction (see FIG. 10).

When the heat transfer tube group 2 is cleaned by stopping the operation of the boiler device, as shown in FIG. 2, the furnace is placed back to back in the substantially central portions of the upper cavity 3a and the lower cavity 3c. Two sound wave generators 4a and 4b and a pair of sound wave generators 4c and 4d are installed toward the wall 1 side, and the sound wave generator 4 is not installed in the intermediate cavity 3b. In the case of this embodiment, all the sound wave generators 4a to 4d are installed so as to face in the furnace width direction, and sound waves are emitted from the central portion of the cavity 3c toward the furnace wall 1 side.

As shown in FIG. 3, the sound wave generator 4 comprises a speaker 5 and a resonance tube 6 attached to the tip of the speaker 5.

The frequency of at least one of the sound wave generators 4 in the pair is adjustable with respect to the frequency set value of the other sound wave generator 4, and as shown in FIG. The inside of the portion 3 becomes the resonance mode 7, and the resonance mode extends to the region where the heat transfer tube group 2 is installed and the cavity 3 where the sound wave generator 4 is not installed, and finally includes the heat transfer tube group 2. The entire flue becomes a resonance mode with almost the same frequency and the same phase.

As shown in FIG. 2, a monitoring camera 8 is installed at an appropriate position (either inside the furnace or outside the furnace) so that the sound wave generator can be seen while observing the state of combustion ash falling from the heat transfer tube group 2. The frequency of the sound wave generator 4 is fixed by adjusting the frequency of No. 4 and at the place where the combustion ash drops off sharply, that is, at the resonance mode.

FIG. 4 is a diagram for explaining the mechanism of vibrating the heat transfer tube group 2 by causing the inside of the cavity 3 to resonate. As shown in the figure, when the sound wave generator 4 constantly generates a high sound pressure portion and a low sound pressure portion in the cavity 3 to enter the resonance mode (the arrow X in the drawing indicates the direction of the sound pressure high and low). (The sound pressure distribution is shown by a dotted waveform A), air particles move from the high sound pressure portion to the heat transfer tube group 2 side, and the air particle is discharged from the heat transfer tube group 2 side in the low sound pressure portion ( The arrow Y in the figure indicates the primary movement direction of air particles. Further, also in the heat transfer tube group 2, a high sound pressure portion and a low sound pressure portion are generated at the same frequency as in the cavity portion 3 and air particles move (an arrow Z in the figure indicates a secondary movement direction of air particles). display). In this way, resonance occurs in the region of the cavity 3 and the heat transfer tube group 2, and the sound pressure distribution at that time becomes a dotted line waveform a, and the vibration width of the gas body is displayed by a solid line waveform b. Combustion ash adhering to and accumulating on the heat pipe drops violently, effectively removing the combustion ash.

When no resonance vibration is generated, the vibration in the heat transfer tube group 2 is attenuated due to the phase difference between the heat transfer tube group 2 and the like, so that the resonance in the cavity 3 above and below the heat transfer tube group 2 is suppressed. It is essential that they have the same phase and the same frequency.

FIG. 5 is a diagram for explaining the second embodiment of the present invention. The difference from the first embodiment is the installation positions of the sound wave generators 4a to 4d. That is, in this embodiment, the sound wave generators 4a and 4b are arranged facing each other in the upper cavity 3a, and the sound wave generators 4c and 4d are arranged opposite each other in the lower cavity 3c.

FIG. 6 is a view for explaining the third embodiment of the present invention. In this embodiment, the sound wave generators 4a and 4b arranged in the upper cavity 3a face each other and the lower side. The sound wave generators 4c and 4d arranged in the hollow portion 3c of the above face upward.

As a modification of this embodiment, the sound wave generator 4
Both a and 4b are arranged facing downward, and the sound wave generator 4c
4d may be arranged to face each other.

FIG. 7 is a diagram for explaining a fourth embodiment of the present invention. In the case of this embodiment, four sound wave generators 4a.about.
4d are all facing upward with a predetermined interval.

As a modification of this embodiment, the sound wave generator 4
It is also possible to arrange all of a to 4d facing downward.

FIG. 8 is a diagram for explaining the fifth embodiment of the present invention. In the case of this embodiment, four sound wave generators 4a.about.
4d has a shape in which the heat transfer tube group 2 of each stage is sandwiched in the vertical direction at a predetermined interval.

FIG. 9 is a view for explaining the sixth embodiment of the present invention. In the case of this embodiment, the sound wave generators 4a and 4b are provided.
However, the sound wave generators 4c and 4d are both arranged back to back in the vertical direction.

As described above, various arrangement states of the sound wave generator 4 are conceivable. In short, one or a plurality of sound wave generators 4 arranged in the cavity 3 may be used to bring the entire flue into a resonance mode.

FIG. 10 is a diagram for explaining the seventh embodiment of the present invention, in which the frequency of one of the sound wave generators 4a arranged in the cavity 3 is set, and the oscillator 9a and the amplification factor are variable. Driven by the power amplifier 10a. The frequency of the other sound wave generator 4b can be varied with respect to the set frequency of the sound wave generator 4a, and is driven by the oscillator 9b and the power amplifier 10b having a variable amplification factor.

The CCD camera 11 and the inspection plate 12 for monitoring the falling state of the combustion ash are provided at appropriate places below the cavity 3 in which the sound wave generators 4a and 4b are arranged, in the furnace width direction (or It is arranged opposite to the furnace direction) and has a CCD
The camera 11 can scan in the width direction of the inspection plate 12. The output signal of the CCD camera 11 is input to the image processing device 13, and the image processing device 13 receives the monitor television 1.
4 is connected, the output signal of the image processing device 13 is input to the frequency controller 15, and the oscillator 9b is drive-controlled based on the input signal.

Line charts such as bar codes, characters, symbols, patterns, etc. are drawn on the inspection board 12 in a stepwise manner such that the number, thickness, and shade are changed. It is intended to detect the amount of ash fall during cleaning by utilizing the fact that the visible range is inversely proportional, and the relationship between the area where the diagram can be detected and the concentration of ash fall (fall ash amount) is in advance or cleaning It is requested quantitatively by receiving the fallen ash in the medium-quantity container.

During cleaning, the range (area) in which the CCD camera 11 can detect the diagram of the inspection plate 12 is optically monitored through the space in which the combustion ash is falling, and the signal is sent to the image processing device 13. The processed image data is input to the television 14 to monitor the descent state of combustion ash on the television 14.

Further, based on the processed image data, it is judged in the frequency controller 15 whether the amount of fall of the combustion ash is the largest, that is, whether the inside of the flue is in the resonance mode, and the judgment is made in the resonance mode. Frequency controller 1 if not reached
The oscillation frequency of the oscillator 9b is sequentially and automatically changed by the signal from 5. Then, when the resonance mode is reached, the oscillation frequency of the oscillator 9b is fixed and the oscillation frequency is fixed for a certain time
The system is such that cleaning is continued while monitoring with the camera 11.

By changing the frequency of the sound wave generator 4 variously, the resonance state is changed to the first-order mode, the second-order mode, the third-order mode, and the fourth-order mode. By moving the portion along the axial direction of the heat transfer tube, the entire heat transfer tube group can be cleanly cleaned. This state can be monitored by the system shown in FIG.

FIG. 11 is a view for explaining the eighth embodiment of the present invention. In the above-mentioned embodiment, a camera was used as a means for detecting whether or not the resonance mode was set. It is detected whether or not the resonance mode is set by the change of the transmitted light intensity. That is, the laser light source 16 and the optical sensor 17 for monitoring the falling state of the combustion ash are arranged at appropriate places so as to face each other in the furnace width direction (or furnace depth direction).

The laser light source 16 is driven so as to have a constant output, and when the amount of fallen ash is small, the laser light source 1
Since the laser light emitted from 6 reaches the optical sensor 17 with almost no scattering due to the fallen ash, the output of the optical sensor 17 is large. When the amount of fallen ash increases, the laser light is scattered by the fallen ash, and accordingly the output of the optical sensor 17 decreases.

Therefore, the relationship between the amount of ash fall and the transmitted light intensity of the laser light (output of the optical sensor 17) is obtained in advance, and the output of the optical sensor 17 is input to the frequency controller 15 so that the optical sensor 17 outputs The resonance mode can be introduced by finely adjusting the frequency of the oscillator 9b so that the output becomes small.

In the above embodiment, the removal of the combustion ash that adheres to and accumulates on the heat transfer tube of the boiler device has been described, but the present invention is not limited to this, and is installed in various plants or various industrial equipment, for example. It is also applicable to cleaning existing pipes.

[0045]

When the sound wave oscillated from the sound wave generator is directly oscillated in the tube group as in the prior art, many small reflected sounds are generated from many tube bodies, and the energy of the oscillating sound wave is advanced. Decreases with Further, the energy of the oscillating sound wave is reduced by the generation of the reflected wave from the wall having a large area.

In order to avoid these reductions, in the present invention, the frequency that synchronizes with the reflected sound in the hollow portion (cavity) without the tubular body (the frequency determined by the distance between the installation position of the sound wave generator and the wall). ) Is caused to oscillate, the oscillation wave energy and the reflected wave energy are superposed, a large resonance energy is continuously held in the cavity, and then the amplified vibration energy is generated in the tube group where many small reflected waves are generated. By gradually expanding and generating the same vibration in the entire tube group as in the cavity, a large vibration is also generated in the space between the tube bodies, and the dust accumulated on the wall surface of the tube body is effectively removed. You can In addition, the conventionally proposed granular material charging chute, the circulation system for reusing the granular material, and the mechanism for separating the granular material from the dust that has fallen are not required, and therefore the size of the device is increased and the cost is high. Is eliminated.

Since it is only necessary to adjust the frequency to bring the inside of the cavity including the tubular body into the resonance mode, the directivity is imparted to the sound wave by the phase control as previously proposed to locally remove dusts. Compared with the method described above, it has the features that it is easier to control and that dust is removed entirely.

[Brief description of drawings]

FIG. 1 is a front view of a rear heat transfer section of a boiler device according to a first embodiment of the present invention.

FIG. 2 is a side view of a rear heat transfer section.

FIG. 3 is a side view of a sound wave generator used in this embodiment.

FIG. 4 is an explanatory diagram showing a mechanism for causing resonance in a cavity.

FIG. 5 is a schematic configuration diagram of a pipe body cleaning apparatus according to a second embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a tubular body cleaning device according to a third embodiment of the invention.

FIG. 7 is a schematic configuration diagram of a tubular body cleaning device according to a fourth embodiment of the invention.

FIG. 8 is a schematic configuration diagram of a tubular body cleaning device according to a fifth embodiment of the invention.

FIG. 9 is a schematic configuration diagram of a pipe body cleaning apparatus according to a sixth embodiment of the present invention.

FIG. 10 is a schematic configuration diagram of a tube body cleaning device according to a seventh embodiment of the invention.

FIG. 11 is a schematic configuration diagram of a pipe body cleaning apparatus according to a seventh embodiment of the present invention.

FIG. 12 is a schematic configuration diagram of a boiler device.

FIG. 13: Combustion ash adheres to the heat transfer tube in the boiler device,
It is sectional drawing which shows the state which accumulates.

FIG. 14 is a schematic configuration diagram of a conventionally proposed cleaning device.

[Explanation of symbols]

 1 Furnace Wall 2 Heat Transfer Tube Group 3 Cavity 4 Sound Wave Generator 5 Speaker 6 Resonance Tube 7 Resonance Mode 8 Monitoring Camera 9a, 9b Oscillator 10a, 10b Power Amplifier 11 CCD Camera 12 Sight Plate 13 Image Processor 14 Monitor TV 15 Frequency Control 16 Laser source 17 Optical sensor G Combustion gas

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koujiro Yamada 3-36 Takaracho, Kure City, Hiroshima Prefecture Babkotuku Hitachi Ltd. Kure Laboratory

Claims (4)

[Claims] 1. A sound wave generator is installed in a cavity formed between a tube group and an adjacent tube group, and a sound wave emitted from the sound wave generator sets the cavity to a resonance mode to produce a tube. A pipe body cleaning device, which removes dusts attached to the body. 2. The frequency according to claim 1, wherein a frequency of a sound wave emitted from the sound wave generator is changeable, and a detection means for detecting whether or not the cavity is in a resonance mode is provided, and the detection is performed. A tubular body cleaning device configured to adjust the frequency of the sound wave generator in a frequency range in which the resonance mode of the cavity is detected by the means. 3. The tube body cleaning device according to claim 1, wherein the position of the antinode of the resonance waveform formed in the cavity is adjustable. 4. The heat transfer tube group is arranged at a predetermined interval along the flow direction of the combustion gas, and a sound wave generator is installed in a cavity formed between the heat transfer tube group and an adjacent heat transfer tube group. Then
A boiler apparatus for removing combustion ash adhering to a tube body by causing a cavity portion including the heat transfer tube group to be in a resonance mode by a sound wave emitted from the sound wave generator.