KR100415066B1 - Silencer for Roots Blower - Google Patents

Abstract

The present invention provides a silencer for a Roots Blue War, which is mounted on a Roots Blue War pipe such as a petrochemical plant to remove noise: each of which has at least two through-holes in a concentric circle in a silencer attached to a blower. A plurality of buffs (A, PA, B, C, D, E) having the same total flow path cross-sectional area of the balls are installed together, and each of the buffs (A, PA, B, C, D, E) The through-holes between the buffs A, PA, B, C, D, and E, which are maintained at different intervals, are arranged to stagger each other.

Accordingly, through various iterative experiments, the performance of the industrial blower silencer installed in the petrochemical plant is improved, thereby improving the working environment.

Description

Silencer for Roots Blue Wars {Silencer for Roots Blower}

The present invention relates to a silencer, and more particularly, to a muffler for Roots Blue War, which improves the performance of an industrial blower silencer installed in a petrochemical plant through various repeated experiments.

In general, a muffler means an acoustic device used to reduce the noise generated by a noise generating machine, and is generally classified into a reflection type and a sound absorption type from an acoustic point of view. In the case of the reflective silencer, the noise reduction is mainly determined by the geometry of the silencer, and the attenuation of the noise is achieved by inducing impedance mismatch using a cylindrical or elliptical extension tube. In the case of the sound absorption type, a sound absorbing material, a void tube, or a combination thereof is used to absorb noise energy.

An ideal muffler means no sound output from the discharge port, which is a physically special situation that means that the outlet is blocked. In other words, it can be considered as a perfect solution in terms of noise reduction, but from the standpoint of the power source that is the source of noise, it means infinite load condition, so the ideal noise reduction is extremely unrealistic.

Therefore, the muffler is a practical function to have the minimum load state allowed by the power source with the maximum reduction of the noise, which is required to optimize the design through the experiment to reproduce the field situation in addition to the theoretical approach.

Therefore, an object of the present invention is to focus on the above point, to provide a muffler for Roots Blue War to improve the performance of the industrial blower silencer installed in the petrochemical plant through various repeated experiments.

1 is an exemplary view showing a configuration of an apparatus for an experiment according to the present invention,

2a to 2f is a configuration diagram of the buffs applied to the experiment according to the present invention,

3 is a configuration diagram showing an arrangement state of the buff for the experiment according to the present invention,

4 is a configuration diagram showing an arrangement state of the buff according to the optimum condition of the present invention;

5A and 5B are diagrams illustrating noise reduction for each frequency band;

Figure 6 is a diagram showing a comparison of noise reduction according to the prior art and the present invention.

Explanation of symbols on the main parts of the drawings

10: noise source 20: silencer

30: buff 30a: conduit

40, 50: sound level meter

In order to achieve the above object, the present invention provides a silencer for Roots Blue War, which is mounted on a Roots Blue War pipe such as a petrochemical plant to remove noise: each of which has at least two through holes in the silencer attached to the blower. In combination with a plurality of buffs (A, PA, B, C, D, E) having a concentric circle and configured to have the same total cross-sectional area of the through holes, each of the buffs (A, PA, B, C, D, E) is characterized in that the through-holes between the buffs (A, PA, B, C, D, E) that are insulated while maintaining different intervals are arranged to be staggered with each other.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is an exemplary view showing the configuration of an apparatus for an experiment according to the present invention, Figure 2a to 2f is a configuration diagram of the buffs applied to the experiment according to the present invention.

The blower to be low noise through the present invention is installed in the petrochemical process to produce propylene (Propylene), the size of the silencer attached to the blower is typically Φ380 (mm) × 1800 (mm). Therefore, various types of buffs installed inside the silencer of Φ380 (mm) × 1800 (mm) size and the buffs that can detect the change of muffler performance according to the arrangement and position of them, and improve the performance of the silencer The purpose of this study is to find the shape, location, array condition and quantity of an experiment by experimental methods.

In the figure, reference numeral 10 denotes a noise source sealed by a casing incorporating a sound absorbing material, reference numeral 20 denotes a muffler type silencer having a variable structure for easy change of an internal flow path, and reference numeral 30 denotes a buff having various types of through holes. Reference numerals 40 and 50 denote noise detectors installed at the inlet and outlet of the silencer 20, and reference numeral 60 denotes a PVC duct extending to the outlet of the silencer 20.

The noise source 10 is a loudspeaker system that generates a noise level of 115 dB between 4 Hz and 100 kHz. Kjær, sound source type 4224). Specifications are 100V ~ 240V / 50Hz ~ 60Hz, 18kg, 480mm (height) × 380mm (width) × 242mm (depth), and 65W rated power.

The silencer 20 is divided into an upper part and a lower part so as to change the arrangement, position, number, etc. of the buff 30 installed therein, and is manufactured in a structure capable of opening and closing the upper part. That is, if you want to change the arrangement, position, number, etc. of the buff 30, open the upper part and rearrange the buff 30 so as to have a desired structure, close the upper part and assemble with a bolt with the lower part so that the sound leaks. Do not. Experimental silencer 20 is produced in the same dimensions and shape as the silencer installed in the field to achieve the same effect as possible. At this time, the inlet portion of the muffler 20 is treated with a curved pipe as shown in order to prevent the fluid from impacting the muffler.

As summarized in Figs. 2A to 2F, the buffs 30 used in the experiment are six types in accordance with the shape and dimensions of the through holes. Figure 2a has five through holes on the concentric circumference, Figure 2b is an additional conduit (30a) is installed in the through hole in one side of Figure 2a, Figure 2c has two through holes. The buff 30 of FIGS. 2A-2C does not have a through hole in the center, whereas the buff 30 of FIGS. 2D-2F includes a through hole of 8, 13, and 25 through holes, respectively. Have

Sound level meter (40) (50) Kjær's Sound Analyzer Type 2260 includes specifications for No. of input and output channels 2, analog filters A and C, frequency range 1 Hz to 20 kHz, storage capacity of 5 Mbbyte (external memory card). Available).

The noise source 10 is placed inside the noise shield box (enclose) to allow the noise generated to pass through the silencer 20 only and to suppress the phenomenon that the noise penetrates to the outside of the noise shield box (encloser) to the maximum. Installing a noise measuring device 50 in the interior of the PVC duct 60 extending to the outlet portion of the silencer 20 to block other noise other than the sound source that may occur during the experiment. In addition, the PVC duct 60 extends outside the laboratory to prevent noise from entering the laboratory.

3 is a configuration diagram showing an arrangement state of the buff for the experiment according to the present invention, Figure 4 is a configuration diagram showing the arrangement state of the buff according to the optimum conditions of the present invention, Figures 5a and 5b is noise for each frequency band Figure 6 is a diagram showing the reduction, Figure 6 is a diagram showing a comparison of noise reduction according to the prior art and the present invention.

In the present invention, to improve the performance of the industrial blower silencer installed in the petrochemical plant, since the external dimensions of the silencer are already determined, the external dimensions are not considered. In addition, it is assumed that there is no temperature gradient for the experiment in the room, and since the flow rate in the silencer is 10-20m / sec or less than 10% of the sound velocity, the influence thereof is ignored. Install a sound level meter at the entrance and exit of the silencer, open the silencer, arrange the buffs at the desired position and angle, and close the silencer. Supply power to the noise source and measure the noise while maintaining the noise level of the sound source at 110dB (A). After the noise measurement for a certain period of time, turn off the noise source and save the data from the sound level meter. Repeat this process while changing the position and angle of the buff. The experiment is discontinued on days with heavy winds to rule out the effects of external noise.

The settings of the noise measuring instruments 40 and 50 are as follows.

SPL Measurement Range: 50dB to 130dB

Bandwith: 1/3 -octave

Peak over: 140dB

Time weighting

Spectrum measurement: Fast

Broad-band status: Fast

Frequency weighting

Broad-band Measurement: AL

Broad-band Status: L

Spectrum Measurement: L

Measurement parameters using the noise measuring instruments 40 and 50 are as follows.

SPL: Sound Pressure Level

L _LF / L _AF Eq: Equivalent continuous level

L _LF / L _AF Max: maximum value detected within the elapsed time

In Fig. 3, the arrangement position of the buff is represented by the distance x from the exit side, and the staggered angle of the buff is represented by the clockwise angle theta of the reference through hole from the vertical center line of the buff. The combination and placement of the entire buff is indicated in order from the exit side, e.g. PA (0 °, 210) -A (36 °, 430) -A (0 °, 640) -A (36 °, 860) -PA ( 0 °, 1070). Here, A, PA, B, C, D, and E refer to the buffs of FIGS. 2A to 2F, respectively, and the same applies in the following description. The reference to the position of the buff is indicated by the number of the number placed from the exit side for convenience.

The number of buff arrangements (type-position-array-combination) to be installed inside the silencer is innumerable, but the noise reduction effect according to the buff arrangement is measured by performing the following steps based only on the cases that can be actually installed. do.

<Experiment 1> Without buff

<Experiment 2> When installing one buff A in different positions

<Experiment 3> When installing two buffs A at equal intervals and changing the angle

<Experiment 4> When installing three buffs A at equal intervals

<Experiment 5> When installing four buffs A at equal intervals

<Experiment 6> When installing 5 buffs A at equal intervals

<Experiment 7> When buff A is concentrated in the middle of silencer

<Experiment 8> When changing the interval and angle of 5 buffs A

<Experiment 9> When installing 5 buff PAs with conduit part 30a

<Experiment 10> Combination of four buff PAs and one of buffs B, C, D and E

<Experiment 11> Combination of 3 buff PAs and 1 buff

<Experiment 12> Combination of 2 buff PAs and 3 different buffs

<Experiment 13> Combination of 5 different buffs

The measurement time was set to 1 minute measurement and 1 minute standby, and a value of 50 dB or more was measured at 1/3 octave band level in the range of 16 Hz to 12.5 kHz. In the experiment process, after reviewing the experimental results at the previous stage, the experimental procedure of the next stage is determined to minimize the number of cases.

<Experiment 1> Without buff

The noise passed without buff is shown in Table 1. The difference between the input and output noise levels was 6.0dB (L) at the equivalent noise level, 5.7dB (A) at the A-corrected equivalent noise level, 3.7dB (L) at the maximum noise level, and A-corrected maximum noise level at the equivalent noise level. The difference was 5.8 dB (A).

INPUT OUTPUT Equivalent Maximum Equivalent Maximum L _L (dB) L _A (dB) L _L (dB) L _A (dB) L _L (dB) L _A (dB) L _L (dB) L _A (dB) Experiment 1 110.1 107.2 112.0 108.0 104.0 101.5 108.3 102.2

<Experiment 2> When installing one buff A in different positions

Since the internal length of the silencer is 1280mm, divide the length into 3 parts and then change the buff position to 320mm Experiment 2-1), 640mm (Experiment 2-2), 840mm (Experiment 2-3) and test the noise reduction effect.

Compare the results of the three experiments (inlet and outlet noise levels) from Table 2. In Experiment 2-2 with the buff in the middle, the difference between the noise level at the inlet and the outlet is 7.9 dB (L) with equivalent noise level, 7.8 dB (A) with A-corrected equivalent noise level, and maximum noise level. 5.7dB (L), A-corrected maximum noise level is 7.5dB (A).

INPUT OUTPUT Epuivalent Maximum Epuivalent Maximum L _L (dB) L _A (dB) L _L (dB) L _A (dB) L _L (dB) L _A (dB) L _L (dB) L _A (dB) Experiment 2-1 110.8 108.1 112.8 108.9 103.1 100.2 106.0 101.2 Experiment 2-2 109.7 107.1 112.0 107.9 101.8 97.1 105.0 98.1 Experiment 2-3 110.7 108.0 112.6 108.7 103.5 100.2 106.9 101.2

<Experiment 3> When installing two buffs A at equal intervals and changing the angle

In order to investigate the noise reduction effect according to the relative position of the through holes of the buff, the position of the buff is fixed to 420mm and 840mm, and the following experiment is performed. The results are shown in Table 3.

Experiment 3-1: Side-by-Side Arrangement: A (0˚, 420) -A (0˚, 840)

Experiment 3-2 Staggered Array: A (0˚, 420) -A (36˚, 840)

INPUT OUTPUT Equivalent Maximum Equivalent Maximum L _L (dB) L _A (dB) L _L (dB) L _A (dB) L _L (dB) L _A (dB) L _L (dB) L _A (dB) Experiment 3-1 110.3 107.7 112.3 108.5 101.9 97.3 105.7 98.6 Experiment 3-2 110.0 107.2 112.0 108.0 102.0 96.8 104.9 97.9

<Experiment 4> When installing three buffs A at equal intervals

Fix the positions of the buffs to 320mm, 640mm, and 960mm, and perform the following experiments, and the results are shown in Table 4.

<Experiment 4-1> Side by side arrangement: A (0˚, 320) -A (0˚, 640) -A (0˚, 960)

<Experiment 4-2> Staggered Exit: A (36˚, 320) -A (0˚, 640) -A (0˚, 960)

Staggered among <Experiment 4-3>: A (0˚, 320) -A (36˚, 640) -A (0˚, 960)

Experiment 4-4 Inlet staggered: A (0˚, 320) -A (0˚, 640) -A (36˚, 960)

Experiment 4-5 Oblique Arrangement: A (0˚, 320) -A (24˚, 640) -A (48˚, 960)

Comparing the noise level difference between the inlet and outlet when three buffs were arranged, the equivalent noise level was 9.2dB (L) and the In Experiment 4-5, which is arranged at an angle, the A-corrected equivalent noise level has an effect of reducing the noise level of 11.2 dB (A).

INPUT OUTPUT Equivalent Maximum Equivalent Maximum L _L (dB) L _A (dB) LL (dB) L _A (dB) LL (dB) L _A (dB) LL (dB) L _A (dB) Experiment 4-1 110.7 108.0 113.2 108.7 102.0 97.2 105.5 98.2 Experiment 4-2 110.8 108.0 113.0 108.8 102.3 97.5 105.1 98.7 Experiment 4-3 110.8 108.1 113.0 108.8 101.6 97.8 104.6 99.1 Experiment 4-4 110.8 108.1 113.6 109.0 102.3 97.3 105.6 98.5 Experiment 4-5 110.8 108.0 113.1 108.7 101.9 96.8 105.0 98.0

<Experiment 5> When installing four buffs A at equal intervals

Four buff positions are fixed to 260mm, 520mm, 780mm, and 1040mm, respectively, and the following experiments are carried out. The results are shown in Table 5.

<Experiment 5-1> A (0˚, 260) -A (0˚, 520) -A (0˚, 780) -A (0˚, 1040)

Experiment 5-2 A (36 °, 260) -A (0 °, 520) -A (0 °, 780) -A (0 °, 1040)

Experiment 5-3 A (0 °, 260) -A (36 °, 520) -A (0 °, 780) -A (0 °, 1040)

Experiment 5-4 A (0 °, 260) -A (0 °, 520) -A (36 °, 780) -A (0 °, 1040)

Experiment 5-5 A (0 °, 260) -A (0 °, 520) -A (0 °, 780) -A (36 °, 1040)

Experiment 5-6 A (0 °, 260) -A (36 °, 520) -A (0 °, 780) -A (36 °, 1040)

<Experiment 5-7> A (0˚, 260) -A (36˚, 520) -A (36˚, 780) -A (0˚, 1040)

<Experiment 5-8> A (0˚, 260) -A (18˚, 520) -A (36˚, 780) -A (54˚, 1040)

In <Experiment 5-1>, <Experiment 5-8> shows side by side arrangement, 1 buff stagger, 2 buff stagger, 3 buff stagger, 4 buff stagger, alternating stagger, middle part stagger, and oblique arrangement .

When four buffs are arranged, the equivalent noise level has a noise reduction effect of 10.5dB (L) between the entrance and exit noise levels in Experiment 5-4. As for equivalent noise, the arrangement of <Experiment 5-7> with the difference of the noise level of 14.9dB (A) shows the best effect.

INPUT OUTPUT Ezuivalent Maximum Ezuivalent Maximum L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) Experiment 5-1 110.7 107.9 113.2 108.7 100.6 94.8 103.4 96.0 Experiment 5-2 110.9 108.3 111.6 108.5 101.1 94.9 104.1 96.5 Experiment 5-3 111.0 108.4 111.7 108.7 101.2 94.1 104.2 95.7 Experiment 5-4 111.0 108.4 111.6 108.6 100.7 93.8 103.8 95.4 Experiment 5-5 110.9 108.3 111.5 108.5 100.9 93.8 103.3 95.2 Experiment 5-6 111.0 108.3 111.8 108.5 100.9 93.9 104.1 95.4 Experiment 5-7 110.9 108.4 111.5 108.6 101.0 93.5 104.0 96.0 Experiment 5-8 110.9 108.2 111.5 108.5 100.8 94.7 103.5 96.1

<Experiment 6> When installing 5 buffs A at equal intervals

When the five buffs are installed at 210 mm, 420 mm, 630 mm, 840 mm, and 1050 mm, the following experiments are performed. The results are shown in Table 6.

Experiment 6-1 A (0 °, 210) -A (0 °, 420) -A (0 °, 630) -A (0 °, 840) -A (0 °, 1050)

Experiment 6-2 A (0 °, 210) -A (0 °, 420) -A (36 °, 630) -A (0 °, 840) -A (0 °, 1050)

Experiment 6-3 A (0 °, 210) -A (0 °, 420) -A (0 °, 630) -A (0 °, 840) -A (36 °, 1050)

Experiment 6-4 A (0 °, 210) -A (36 °, 420) -A (0 °, 630) -A (36 °, 840) -A (0 °, 1050)

Experiment 6-5 A (36 °, 210) -A (36 °, 420) -A (0 °, 630) -A (0 °, 840) -A (0 °, 1050)

Experiment 6-6 A (0˚, 210) -A (0˚, 420) -A (0˚, 630) -A (36˚, 840) -A (36˚, 1050)

Experiment 6-7 A (0 °, 210) -A (36 °, 420) -A (36 °, 630) -A (36 °, 840) -A (0 °, 1050)

Experiment 6-8 A (0 °, 210) -A (15 °, 420) -A (30 °, 630) -A (45 °, 840) -A (60 °, 1050)

In Experiment 6-1, Experiment 6-8 is a side-by-side arrangement, buff 3 staggered, buff 5 staggered, alternating staggered, buff 1,2 staggered, buff 4, 5 staggered, 3 staggered among Represents an oblique array.

INPUT OUTPUT Equibvalent Maximim Equivalent Maximim L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) Experiment 6-1 110.7 108.1 111.3 108.4 100.6 92.2 103.4 94.0 Experiment 6-2 110.7 108.0 111.3 108.2 100.3 92.2 105.1 95.4 Experiment 6-3 110.9 108.2 111.7 108.4 101.1 92.6 104.4 94.6 Experiment 6-4 110.8 108.1 111.7 108.4 100.3 93.1 103.3 94.9 Experiment 6-5 110.8 107.9 111.6 108.2 100.2 92.1 103.6 94.5 Experiment 6-6 1108. 108.1 111.4 108.4 102.2 92.8 102.9 94.6 Experiment 6-7 110.8 108.0 111.3 108.3 100.0 91.7 104.7 94.9 Experiment 6-8 110.8 108.0 111.6 108.3 100.0 91.7 102.9 93.8

According to Table 6, the difference between the equivalent noise level and the A-calibrated equivalent noise level at the inlet and outlet sides of Experiment 6-7 and Experiment 6-8 was 10.8 dB (L) and 16.3 dB (A), respectively. Both experiments have the same level of noise reduction. The maximum noise level was 6.7dB (L) in <Experiment 6-7> and 8.7dB (L) in <Experiment 6-8>, and the A-corrected maximum noise level was 13.4 in <Experiment 6-7>. There is a noise level difference of 14.5 dB (A) in dB (A) and Experiment 6-8.

<Experiment 7> When buff A is concentrated in the middle of silencer

In order to find out the effect when the buff is concentrated, two or more buffs are concentrated around the position of 640mm and the following experiment is performed.

<Experiment 7-1> A (0 °, 637) -A (0 °, 642)

Experiment 7-2 A (0 °, 635) -A (0 °, 640) -A (0 °, 645)

Experiment 7-3 A (0 °, 633) -A (0 °, 637) -A (0 °, 642) -A (0 °, 647)

Experiment 7-4 A (0 °, 630) -A (0 °, 635) -A (0 °, 640) -A (0 °, 645) -A (0 °, 650)

Experiment 7-5 A (0 °, 630) -A (36 °, 635) -A (0 °, 640) -A (36 °, 645) -A (0 °, 650)

In <Experiment 7-1>, <Experiment 7-5> represents two close contact, three close contact, four close contact, five close contact, and five staggered contact.

INPUT OUTPUT Equivalent Maximum Equivalent Maximum L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) Experiment 7-1 110.9 108.3 113.0 109.0 102.5 98.4 106.1 99.2 Experiment 7-2 110.9 108.3 113.0 109.1 102.5 99.1 105.6 100.2 Experiment 7-3 110.8 108.0 111.4 108.2 102.2 98.0 105.3 99.1 Experiment 7-4 111.1 108.5 113.0 109.2 102.0 98.0 104.4 100.2 Experiment 7-5 111.1 108.5 113.0 109.3 101.9 97.8 104.3 99.3

Looking at the results in Table 7, you can get better results as you increase the number of buffs. The sound pressure difference between the entrance and the exit of Experiment 7-4 with five buff through-holes arranged side by side and Experiment 7-5 with the buff through-holes staggered is equivalent to 9.1dB of equivalent noise level. (L) and 10.5 dB (L), and the A-corrected equivalent noise level difference is 10.5 dB (A) and 10.7 dB (A), respectively. Therefore, when the buff is in close contact, arranging a large number of buffs but staggering the through-holes rather than arranging the through-holes side by side, it can be seen that the noise reduction effect is greater.

<Experiment 8> When changing the interval and angle of 5 buffs A

When arranged close to the exit:

<Experiment 8-1-1> A (0 °, 200) -A (0 °, 300) -A (0 °, 450) -A (0 °, 650) -A (0 °, 900)

<Experiment 8-1-2> A (0˚, 200) -A (36˚, 300) -A (0˚, 450) -A (36˚, 650) -A (0˚, 900)

In center dense arrangement:

Experiment 8-2-1 A (0˚, 340) -A (0˚, 540) -A (0˚, 640) -A (0˚, 740) -A (0˚, 940)

Experiment 8-2-2 A (0 °, 340) -A (36 °, 540) -A (0 °, 640) -A (36 °, 740) -A (0 °, 940)

When arranged close to the entrance:

Experiment 8-3-1 A (0˚, 350) -A (0˚, 600) -A (0˚, 800) -A (0˚, 950) -A (0˚, 1050)

<Experiment 8-3-2> A (0˚, 350) -A (36˚, 600) -A (0˚, 800) -A (0˚, 950) -A (0˚, 1050)

<Experiment 8-1-1>, <Experiment 8-2-1>, and <Experiment 8-3-1> represent an array side by side, and <Experiment 8-1-2>, <Experiment 8-2-2> And <Experiment 8-3-2> show a staggered arrangement.

INPUT OUTPUT Equivalent Maximum Equivalent Maximum L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) Experiment 8-1-1 110.8 108.0 111.4 108.2 100.1 91.4 103.2 93.4 Experiment 8-1-2 110.8 108.0 111.5 108.2 99.6 91.0 103.0 93.9 Experiment 8-2-1 110.8 108.1 111.4 108.3 100.7 93.2 103.6 95.3 Experiment 8-2-2 110.8 108.0 111.6 108.3 101.3 92.3 104.6 94.4 Experiment 8-3-1 110.7 108.1 111.3 108.3 99.9 91.3 102.9 93.5 Experiment 8-3-2 110.8 108.1 111.4 108.3 99.7 91.1 102.8 93.2

From Table 8, it can be seen that a good noise reduction effect can be obtained by arranging closer to the inlet or the outlet than to the center. So far it has been experimented using Buff A (FIG. 2A). The experiment is then performed on the combination of buff PA, buffs B, C, D, and E, with a pipe of diameter 85mm and protrusion length 130mm on buff A. In this experiment, the number of experiments is minimized by planning the next experiment based on the experimental results so far to find the optimal placement condition of the buff.

According to the experimental results so far, it was found that the staggered arrangement of the buff through holes is more effective than the side-by-side arrangement. Therefore, experiment with arranging the buffs as staggered as possible. However, when buffs B, C, D, and E are mixed and arranged, the effect of the angular angle cannot be greatly expected due to the large number of through holes or the difference in relative shape. Therefore, the angles should be changed only when the same buff is placed next to each other. .

<Experiment 9> When installing 5 buff PAs with conduit part 30a

Five buff PAs are placed at 210mm, 430mm, 640mm, 860mm, and 1070mm, respectively.

<Experiment 9-1> PA (0˚, 210) -PA (36˚, 430) -PA (0˚, 640) -PA (36˚, 860) -PA (0˚, 1070)

Experiment 9-2 PA (0 °, 210) -PA (18 °, 430) -PA (36 °, 640) -PA (54 °, 860) -PA (72 °, 1070)

INPUT OUTPUT Equivalent Maximum Equivalent Maximum L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) Experiment 9-1 110.5 107.9 112.7 108.6 98.3 90.2 102.2 92.0 Experiment 9-2 110.4 107.9 112.3 108.7 98.5 89.7 102.7 92.0

The sound pressure difference between the inlet and the outlet of Experiment 9-1 and Experiment 9-2 shows that the sound pressure difference of 12.2dB (L) and 11.9dB (L) is equivalent to A correction equivalent level. The noise level is 11.9dB (A) and 18.2dB (A). Compared with the results in Table 6, which do not fit the pipe-shaped conduit 20a, it is better than the largest sound pressure difference in Table 6, 10.8dB (L _L ) and 16.3dB (L _A ).

<Experiment 10> Combination of four buff PAs and one of buffs B, C, D and E

In this case, five buffs are used, and the positions of the five buffs are fixed at 210 mm, 430 mm, 640 mm, 860 mm, and 1070 mm, respectively, and the following experiments are conducted.

1) Combination of 4 Buff PAs and 1 Buff B

<Experiment 10-1-1> PA (0˚, 210) -B (0˚, 430) -PA (36˚, 640) -PA (0˚, 860) -PA (36˚, 1070)

<Experiment 10-1-2> PA (0˚, 210) -PA (36˚, 430) -PA (0˚, 640) -B (860) -PA (36˚, 1070)

2) Combination of 4 Buff PAs and 1 Buff E

<Experiment 10-2-1> PA (0˚, 210) -E (0˚, 430) -PA (36˚ 640) -PA (0˚ 860) -PA (36˚ 1070)

<Experiment 10-2-2> PA (0˚ 210) -PA (36˚ 430) -PA (0˚ 640) -E (0˚ 860) -PA (36˚ 1070)

3) Combination of four buff PAs and one of buffs B, C, D and E on the exit side

<Experiment 10-3-1> B (0˚ 210) -PA (0˚ 430) -PA (36˚ 640) -PA (0˚ 860) -PA (36˚ 1070)

<Experiment 10-3-2> C (0˚ 210) -PA (0˚ 430) -PA (36˚ 640) -PA (0˚ 860) -PA (36˚1070)

<Experiment 10-3-3> D (0˚ 210) -PA (0˚ 430) -PA (36˚ 640) -PA (0˚ 860) -PA (36˚ 1070)

<Experiment 10-3-4> E (0˚ 210) -PA (0˚ 430) -PA (36˚ 640) -PA (0˚ 860) -PA (36˚ 1070)

4) Combination of four buff PAs and one of buffs B, C, D and E at the entrance

<Experiment 10-4-1> PA (0˚ 210) -PA (36˚ 430) -PA (0˚ 640) -PA (36˚ 860) -B (0˚ 1070)

<Experiment 10-4-2> PA (0˚ 210) -PA (36˚ 430) -PA (0˚ 640) -PA (36˚ 860) -C (0˚ 1070)

<Experiment 10-4-3> PA (0˚ 210) -PA (36˚ 430) -PA (0˚ 640) -PA (36˚ 860) -D (0˚ 1070)

<Experiment 10-4-4> PA (0˚ 210) -PA (36˚ 430) -PA (0˚ 640) -PA (36˚ 860) -E (0˚ 1070)

5) Combination of four buff PAs and one of buffs B, C, D and E in the center

<Experiment 10-5-1> PA (0˚ 210) -PA (36˚ 430) -B (0˚ 640) -PA (0˚ 860) -PA (36˚ 1070)

<Experiment 10-5-2> PA (0˚ 210) -PA (36˚ 430) -C (0˚ 640) -PA (0˚ 860) -PA (36˚ 1070)

<Experiment 10-5-3> PA (0˚ 210) -PA (36˚ 430) -D (0˚ 640) -PA (0˚ 860) -PA (36˚1070)

<Experiment 10-5-4> PA (0˚ 210) -PA (36˚ 430) -E (0˚ 640) -PA (0˚ 860) -PA (36˚ 1070)

In Experiment 10-1 and Experiment 10-2 of Table 10, it is better to change the diameter of the buffs near the inlet than to change the diameter of the through-holes of the buffs near the outlet. . And when placing buff B (diameter 135) with two through holes and buff E (diameter 40) with 25 through holes at the entrance side of Experiment 10-4-1, 10-4-4> The equivalent noise level difference at the entrance is about 12dB (L), which is good at reducing noise. It can be seen that the noise reduction effect is good if the arrangement so that the difference between the through-hole diameter of the buff and the through-hole diameter of the PA.

INPUT OUTPUT Equivalent Maximum Equivalent Maximum L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) Experiment 10-1-1 110.3 107.6 112.2 108.6 98.5 89.6 102.3 91.7 Experiment 10-1-2 110.3 107.6 112.3 108.4 97.8 88.8 102.0 91.4 Experiment 10-2-1 110.3 107.6 112.1 108.4 98.4 904 102.0 92.4 Experiment 10-2-2 110.4 107.7 113.2 108.5 97.3 89.5 100.7 91.3 Experiment 10-3-1 110.6 108.0 113.0 108.7 98.1 90.9 101.5 92.7 Experiment 10-3-2 110.6 108.1 111.1 108.3 97.1 91.0 100.5 92.8 Experiment 10-3-3 110.6 108.1 111.2 108.4 97.0 90.7 100.0 92.3 Experiment 10-3-4 110.5 107.9 111.4 108.2 97.9 90.0 101.5 92.1 Experiment 10-4-1 110.4 107.7 112.5 108.3 98.4 89.3 102.2 92.1 Experiment 10-4-2 110.4 107.6 112.3 108.3 99.3 91.0 102.7 93.2 Experiment 10-4-3 110.4 107.7 112.2 108.4 99.7 90.3 103.8 93.1 Experiment 10-4-4 110.3 107.5 112.4 108.1 98.2 90.4 102.0 92.4 Experiment 10-5-1 97.2 88.0 101.2 90.5 Experiment 10-5-2 110.5 108.0 112.6 108.8 97.3 90.1 100.6 91.8 Experiment 10-5-3 110.6 108.0 112.6 108.7 97.2 90.0 102.5 93.3 Experiment 10-5-4 110.5 108.0 112.6 108.6 97.4 90.4 103.6 93.6

<Experiment 11> Combination of 3 buff PAs and another buff

In this case, all four buffs are used.

1) Place the four buffs at 210mm, 430mm, 860mm and 1070mm respectively.

<Experiment 11-1-1> E (0 °, 210) -PA (0 °, 430) -B (0 °, 860) -PA (36 °, 860) -PA (0 °, 1070)

<Experiment 11-1-2> B (0 °, 210) -B (0 °, 430) -PA (0 °, 860) -PA (36 °, 860) -PA (0 °, 1070)

<Experiment 11-1-3> B (0 °, 210) -PA (0 °, 430) -B (0 °, 860) -PA (36 °, 860) -PA (0 °, 1070)

<Experiment 11-1-4> PA (0 °, 210) -E (0 °, 430) -PA (36 °, 860) -B (0 °, 860) -PA (0 °, 1070)

Experiment 11-1-5 PA (0 °, 210) -B (0 °, 430) -PA (36 °, 860) -B (0 °, 860) -PA (0 °, 1070)

<Experiment 11-1-6> PA (0 °, 210) -B (0 °, 430) -PA (36 °, 860) -E (0 °, 860) -PA (0 °, 1070)

2) Position the four buffs at 210mm, 460mm, 640mm, 800mm, and 1070mm, respectively.

<Experiment 11-2-1> PA (0 °, 210) -E (0 °, 460) -PA (36 °, 640) -D (0 °, 800) -PA (0 °, 1070)

<Experiment 11-2-2> E (0 °, 210) -PA (0 °, 460) -PA (36 °, 640) -B (0 °, 800) -PA (0 °, 1070)

<Experiment 11-2-3> E (0 °, 210) -PA (0 °, 460) -PA (36 °, 640) -D (0 °, 800) -PA (0 °, 1070)

3) Place the four buffs at 150mm, 430mm, 640mm, 860mm and 1070mm, respectively.

<Experiment 11-3-1> PA (0 °, 150) -E (0 °, 430) -PA (36 °, 640) -D (0 °, 860) -PA (0 °, 1070)

INPUT OUTPUT Equivalent Maximum Equivalent Maximum L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) Experiment 11-1-1 110.3 107.7 112.6 108.5 96.2 89.8 101.1 91.7 Experiment 11-1-2 110.1 107.5 112.3 108.3 98.6 91.6 102.3 93.4 Experiment 11-1-3 110.3 107.6 112.0 108.5 96.5 89.8 99.3 92.3 Experiment 11-1-4 110.3 107.6 112.2 108.5 96.7 88.6 100.4 90.9 Experiment 11-1-5 110.4 107.6 112.4 108.5 97.6 89.6 102.1 91.9 Experiment 11-1-6 110.3 107.5 112.6 108.4 96.2 88.0 100.8 90.6 Experiment 11-2-1 110.4 107.6 112.6 108.3 96.6 89.6 101.5 91.8 Experiment 11-2-2 110.3 107.6 113.2 108.6 96.1 88.1 96.1 88.1 Experiment 11-2-3 110.3 107.7 112.8 108.6 95.8 89.6 99.3 91.0 Experiment 11-3-1 110.3 107.6 112.3 108.3 96.7 91.1 101.3 92.9

Of the above experiments, <Experiment 11-2-2> and <Experiment 11-1-6> show the best noise reduction effect. In <Experiment 11-2-2> and <Experiment 11-1-6>, the difference between the exit and inlet of the equivalent noise level is 14.2dB (L) and 14.1dB (L), respectively. The difference between the exit side and the inlet side shows the same level of noise reduction effect (19.5 dB (A)). The arrangement of these two experiments shows that the diameters of the two buffs at the exit and the inlet are arranged alternately, large and small.

<Experiment 12> Combination of 2 buff PAs and 3 other buffs

1) The five buff positions are 210mm, 430mm, 640mm, 860mm and 1070mm, respectively.

Experiment 12-1-1 PA (0 °, 210) -E (0 °, 430) -PA (36 °, 640) -D (0 °, 860) -B (0 °, 1070)

Experiment 12-1-2 PA (0 °, 210) -E (0 °, 430) -D (0 °, 640) -PA (36 °, 860) -B (0 °, 1070)

Experiment 12-1-3 PA (0 °, 210) -C (0 °, 430) -E (0 °, 640) -B (0 °, 860) -PA (0 °, 1070)

Experiment 12-1-4 PA (0 °, 210) -E (0 °, 430) -C (0 °, 640) -B (0 °, 860) -PA (36 °, 1070)

Experiment 12-1-5 E (0 °, 210) -PA (0 °, 430) -D (0 °, 640) -PA (36 °, 860) -B (0 °, 1070)

2) The positions of the five buffs are set to 150 mm, 430 mm, 640 mm, 860 mm and 1070 mm, respectively.

<Experiment 12-2-1> E (0 °, 150) -PA (0 °, 430) -D (0 °, 640) -PA (36 °, 860) -B (0 °, 1070)

<Experiment 12-2-2> E (0 °, 150) -PA (0 °, 430) -B (0 °, 640) -PA (36 °, 860) -B (0 °, 1070)

<Experiment 12-2-3> E (0 °, 150) -PA (0 °, 430) -B (0 °, 640) -PA (36 °, 860) -D (0 °, 1070)

3) The positions of the five buffs are set to 150 mm, 430 mm, 600 mm, 860 mm and 1070 mm, respectively.

Experiment 12-3-1 E (0 °, 150) -PA (0 °, 430) -B (0 °, 600) -PA (36 °, 860) -B (0 °, 1070)

4) The positions of the five buffs are set to 166mm, 466mm, 632mm, 932mm and 1100mm, respectively.

Experiment 12-4-1 E (0 °, 166) -PA (0 °, 466) -D (0 °, 632) -PA (36 °, 932) -B (0 °, 1100)

Experiment 12-4-2 E (0 °, 166) -PA (0 °, 466) -B (0 °, 632) -PA (36 °, 932) -B (0 °, 1100)

INPUT OUTPUT Equivalent Maximum Equivalent Maximum L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) Experiment 12-1-1 110.2 107.3 112.4 108.2 98.4 90.9 102.9 92.9 Experiment 12-1-2 110.0 107.1 112.3 107.9 98.7 92.0 103.3 94.5 Experiment 12-1-3 110.2 107.7 112.1 108.6 97.8 92.4 101.0 94.3 Experiment 12-1-4 100.2 107.6 112.2 108.4 97.9 92.3 101.0 93.9 Experiment 12-1-5 110.0 107.2 112.0 107.9 96.0 91.2 98.8 92.6 Experiment 12-2-1 110.2 107.5 112.6 108.4 95.9 90.3 98.9 91.5 Experiment 12-2-2 110.5 107.8 112.7 108.7 96.0 88.0 98.9 89.5 Experiment 12-2-3 110.2 107.3 112.1 108.1 97.2 90.4 100.6 92.2 Experiment 12-3-1 110.4 108.0 112.6 108.6 95.6 88.6 98.4 90.3 Experiment 12-4-1 110.2 107.4 113.5 108.2 95.1 89.2 98.2 90.7 Experiment 12-4-2 110.3 107.7 108.3 112.5 96.5 91.5 98.9 93.2

Experiments 12-2-2 and 12-3-1 showed the best results, except that the position of buff 3 was different and the arrangement was (E-PA-B-PA-B). Big and small are arranged alternately.

<Experiment 13> Combining 5 different buffs

Five buffs are placed at 150mm, 430mm, 640mm, 860mm, and 1070mm respectively and the following experiment is performed.

Experiment 13-1 E (0 °, 150) -D (0 °, 430) -C (0 °, 640) -A (0 °, 860) -B (0 °, 1070)

INPUT OUTPUT Equivalent Maximum Equivalent Maximum L _{L (} dB) L _^ (dB) L _{L (} dB) L _^ (dB) L _{L (} dB) L _^ (dB) L _{L (} dB) L _^ (dB) Experiment 13-1 110.2 107.4 112.2 108.2 101.9 95.6 105.6 97.5

Experimental results show that the noise attenuation of the muffler can be obtained by arranging the buffs as follows.

① The greater the number of buffs, the higher the noise reduction effect.

② Arrange the staggered through-holes side by side rather than side by side.

③ If you arrange the buff without changing the distance, you can find the arrangement that will make the noise reduction effect bigger.

④ Changing the shape of the buff greatly reduces the noise. At this time, as the diameter of the buff through hole increases toward the exit, the noise does not decrease as much as the sound increases in the funnel-shaped enlargement tube. It's a good idea to use a buff that has.

⑤ The overall arrangement satisfies ④ above, and it is effective to reduce noise by arranging alternating small and large without gradually decreasing the diameter of the buff through hole toward the exit.

⑥ It is effective to reduce noise by inserting pipes to some of the buffs.

Even if there is a method to reduce the noise, the conditions for use in the field, i.e., the fluid must be allowed to flow at high speed, so the number of buffs should not be increased or the through hole should be made small so that the pump cannot be used. The buff was produced and used so that the cross-sectional area of the piercing through hole might be constant.

The following are five kinds of arrangements that produced the best noise reduction effect among the experiments conducted in the present invention.

Experiment 11-2-2 E (0 °, 210) -PA (0 °, 460) -PA (36 °, 640) -B (0 °, 800) -PA (0 °, 1070)

Experiment 11-2-3 E (0 °, 210) -PA (0 °, 460) -PA (36 °, 640) -D (0 °, 800) -PA (0 °, 1070)

Experiment 12-2-2 E (0 °, 150) -PA (0 °, 430) -B (0 °, 640) -PA (36 °, 860) -B (0 °, 1070)

Experiment 12-3-1 E (0 °, 150) -PA (0 °, 430) -B (0 °, 600) -PA (36 °, 860) -B (0 °, 1070)

Experiment 12-4-1 E (0 °, 166) -PA (0 °, 466) -D (0 °, 632) -PA (36 °, 932) -B (0 °, 1100)

INPUT OUTPUT Equivalent Maximum Equivalent Maximum L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) L _L (dB) L _^ (dB) Experiment 11-2-2 110.3 107.6 113.2 108.6 96.1 88.1 99.0 90.1 Experiment 11-2-3 110.3 107.7 112.8 108.6 95.8 89.6 99.3 91.0 Experiment 12-2-2 110.5 107.8 112.7 108.7 96.0 88.0 98.9 89.5 Experiment 12-3-1 110.4 108.0 112.6 108.6 95.6 88.6 98.4 90.3 Experiment 12-4-1 110.2 107.4 113.5 108.2 95.1 89.2 98.2 90.7

From Table 14 we can see that:

(1) All the buffs are buffs (E) with 25 through holes, with the smallest diameter of the through holes arranged.

② Buff No. 2 is a buffing pipe (PA). In the three arrangements of <Experiment 12-2-2, 12-3-1, 12-4-1>, three of the five superior, PA, B, and D are alternately installed. In other words, the large through holes and the small through holes are alternately provided.

③ From Table 15, the maximum noise reduction effect (19.8dB (A)) is shown at <Experiment 12-2-2> at the A-compensated equivalent noise level, and the maximum at <Experiment 12-4-1> at the equivalent noise level. It shows a large noise reduction effect (95.1dB (L)). Also, Experiment 12-2-2 shows noise reduction effect of 14.8dB (L) at equivalent noise level, and A correction equivalent noise level has noise reduction effect of 19.4dB (A).

Experiment Equivalent Noise Level (L _L (dB)) A Compensated Equivalent Noise Level (L _^ (dB)) Maximum equivalent noise level (L _L Max (dB)) Maximum A Compensated Equivalent Noise Level (L _L Max (dB) Experiment 11-2-2 14.5 (3) 18.1 (5) 13.5 (5) 17.6 (4) Experiment 11-2-3 14.2 (5) 19.5 (2) 14.2 (2) 18.5 (2) Experiment 12-2-2 14.5 (3) 19.8 (1) 13.8 (4) 19.2 (1) Experiment 12-3-1 4.8 (2) 19.4 (3) 14.2 (2) 18.3 (3) Experiment 12-4-1 15.1 (1) 18.2 (4) 15.3 (1) 17.5 (5)

In order to improve the performance of the muffler type, the optimum structure of internal structure (buffer shape, location, arrangement, number, etc.) was found through experiments, and five structures are proposed as the optimal arrangement. This reduced the noise level of about 14 dB (input: 110.3 dB (L), output: 95.8 dB (L)) during laboratory tests, and compared the results with a silencer of 4.1 to 5.0 dB ( L) or 5.0 to 6.7 dB (A) has the performance of further reducing noise.

In the case of the existing silencer, the sound absorbing material attached to the inner wall of the silencer is easy to be lost, so that the sound absorbing material is prevented by lagging the outer wall of the silencer to maintain the function of the sound absorber as a sound absorbing type.

According to the above configuration and operation, the present invention has the effect of improving the performance of the industrial blower silencer installed in the petrochemical plant through various repeated experiments to improve the working environment.

It is apparent to those skilled in the art that the present invention is not limited to the described embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or variations will have to belong to the claims of the present invention.

Claims (6)

In the Roots Blue War silencer mounted on the Roots Blue War pipe of a petrochemical plant to remove noise: Inside the silencer attached to the blower, a plurality of buffs (A, PA, B, C, D, E) each having at least two through holes concentrically and having the same total cross-sectional area of the through holes are formed. In combination with snow, each of the buffs (A, PA, B, C, D, E) is a through-hole between the buffs (A, PA, B, C, D, E) in the snow while maintaining a different distance from each other The silencer for Roots Blue Wars, characterized in that arranged staggered. The method of claim 1, In the silencer having the size of Φ 380 (mm) * 1800 (mm), The buff is arranged in the state of E (0 °, 210) -PA (0 °, 460) -PA (36 °, 640) -B (0 °, 800) -PA (0 °, 1070) A silencer for the Roots Blue War. The method of claim 1, In the silencer having the size of Φ 380 (mm) * 1800 (mm), The buff is disposed in the state of E (0 °, 210)-PA (0 °, 460)-PA (36 °, 640)-D (0 °, 800)-PA (0 °, 1070) A silencer for the Roots Blue War. The method of claim 1, In the silencer having the size of Φ 380 (mm) * 1800 (mm), The buff is arranged in the state of E (0 °, 150) -PA (0 °, 430) -B (0 °, 640) -PA (36 °, 860) -B (0 °, 1070) A silencer for the Roots Blue War. The method of claim 1, In the silencer having the size of Φ 380 (mm) * 1800 (mm), The buff is disposed in the state of E (0 °, 150) -PA (0 °, 430) -B (0 °, 600) -PA (36 °, 860) -B (0 °, 1070). A silencer for the Roots Blue War. The method of claim 1, In the silencer having the size of Φ 380 (mm) * 1800 (mm), The buff is disposed in the state of E (0 °, 166) -PA (0 °, 466) -D (0 °, 632) -PA (36 °, 932) -B (0 °, 1100). A silencer for the Roots Blue War.