JPH0596113A - Bag filter dust collector - Google Patents

Abstract

PURPOSE:To maintain the performance of shaking down dust and further to decrease the noise generated on pulse air discharge in a bag filter dust collector. CONSTITUTION:In a blow tube 5 having a pulse valve 6, holes 5a are formed located opposite to openings 2a of filter cloth 2 hanging, and from the blow tube 5, pipes concentrically located with the holes 5a are hung. At the same time, porous disks are fitted to the tips of the pipes to form nozzles 7 from which pulse air is discharged to inside the filter cloths 2, causing dust stuck on the filter cloths to be shaken down.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bag filter dust collector, and more particularly to a bag filter dust collector having a pulse air dust removing mechanism.

[0002]

2. Description of the Related Art Conventionally, as a dust removing measure or a powder collecting means for maintaining a good working environment, a bag filter dust collecting apparatus of a pulse air blowing type has been adopted in various fields of the industrial world. This is a bag-shaped filter cloth that is hung vertically to capture dust in the passing air, while high-pressure compressed air is momentarily discharged as pulse air to the filter cloth that has become clogged. The dust collection performance is maintained by brushing off the captured dust. At this time, since the pulsed air is ejected from the nozzle at a speed close to the sound velocity, a high frequency sound of 2000 to 4000 Hz (hereinafter referred to as “pulse sound”) is generated. However, in recent years, with the increase in size of dust collectors, pulse valves for generating pulsed air have also come to have large diameters, so the pulse noise becomes louder and the noise environment around the dust collectors increases. Is getting worse. Therefore, noise is reduced by enclosing the entire dust collector with a soundproof material.

[0003]

However, in the above soundproofing measures, it is difficult to obtain the soundproofing effect at a low cost because the mounting area of the soundproofing material is huge and the material cost and the construction cost are large. Furthermore, soundproofing measures against exhaust are difficult and incomplete. Therefore, in the present invention, while maintaining the dust removal performance, by reducing the pulse sound generated from the nozzle during pulse air ejection,
The technical issue to be solved is to obtain the noise reduction effect inexpensively and surely.

[0004]

The technical means for solving the above-mentioned problems is to construct a bag filter dust collector as follows. That is, a bag-shaped filter cloth is hung vertically to capture dust in passing air, while pulse air is discharged into the filter cloth through a tubular nozzle provided in a blow tube having a pulse valve. By
In a bag filter dust collector configured to brush off dust adhering to the filter cloth, a pipe member is vertically installed at a position concentric with the hole provided in the blow tube, and at the tip of the pipe member. A perforated plate is provided to form the nozzle. Alternatively, a pipe member having substantially the same inner diameter as the hole diameter is vertically provided at a position concentric with the hole provided in the blow tube, and the ratio of the length L to the inner diameter D is D /
The L is in the range of 0.09 to 0.19 to form the nozzle.

[0005]

According to the present invention, in the bag filter dust collector, the nozzle is provided by vertically arranging a pipe member at a position concentric with the hole formed in the blow tube and by providing a perforated plate at the tip of the pipe member. Therefore, as shown in the experimental results described later, it is possible to reduce the pulse sound generated at the time of ejecting the pulsed air while maintaining the dust removal performance. Alternatively, a pipe member having substantially the same inner diameter as the hole diameter is vertically provided at a position concentric with the hole provided in the blow tube, and the ratio D / L of the length L to the inner diameter D of the pipe member is 0.09.
Since the nozzles are formed in the range of 0.19, it is possible to reduce the pulse sound generated at the time of discharging the pulsed air while maintaining the dust removal performance, as shown in the experimental results described later.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a main part of a bag filter dust collector. A plurality of bag-shaped filter cloths 2 are vertically provided in a cross section of a ventilation path in a case 1 which constitutes a ventilation duct, and air blown by a blower (not shown) or the like passes through the filter cloths 2. At this time, dust in the air can be captured by the outer wall of the filter cloth 2. The filter cloth 2 is a non-woven fabric made of short fibers such as polyester, and has a diameter of 130 to 20 when used in a large bag filter dust collector.
It is formed in a cylindrical bag shape of 0 mm and a length of 6 to 7 m. Further, above the filter cloth 2, a pulse air ejection mechanism 3 for appropriately removing dust attached to the filter cloth 2 is provided.

FIG. 2 is a perspective view showing the pulse air ejection mechanism 3, and FIG. 3 is a sectional view taken along the line AA in FIG. In both figures, a required number of cylindrical blow tubes 5 made of metal or synthetic resin are attached to a header tube 4 connected to a high-pressure compressed air source (not shown). Each header tube 4 is further provided with a pulse valve 6 having a diaphragm 6a for instantaneously (about 0.1 seconds) discharging high-pressure compressed air as pulse air so that each blow tube 5 blows the pulse air. It is configured so that it can be supplied into the tube 5. The other end of the blow tube 5 is extended from the header tube 4 in a direction perpendicular to the axis, and nozzles 7 to 7 are provided at a predetermined pitch in the longitudinal direction, that is, at a position that can face the opening 2a of the filter cloth 2. There is. The nozzle 7 is a cylindrical pipe (also referred to as a pipe member) at a position concentric with the hole 5a formed in the blow tube 5.
As shown in FIG. 4, a perforated disc 7b is attached to the tip of the pipe 7a. Perforated disk 7b
5, a plurality of small holes 7c are opened, the diameter of the small holes 7c is 5 to 15 mm, and the ratio S of the total opening area S1 of the plurality of small holes 7c to the area S2 of the holes 5a is S.
1 / S2 is within the range of 0.7 to 2.0. The shape of the perforated disc 7b is not limited to this embodiment, and the small hole 7c may be formed in a shape other than a circle, for example, a small hole 7d having a shape as shown in FIG. ,
It is also possible to change the arrangement. Further, the perforated circular plate 7b is not limited to a flat plate and may be formed to have a curved surface.

Next, a second embodiment of the present invention will be described. FIG. 7 is a sectional view showing the nozzle 8. The configuration of the bag filter dust collector other than the nozzle 8 is the same as that of the first embodiment. In the figure, a blow tube 5 is provided with a hole 5b at a position where it can face the opening 2a of the filter cloth 2, and at a concentric position, a cylindrical pipe (also referred to as a pipe member) having the same inner diameter as the hole diameter. ) 8a is provided vertically. From the result of the experiment described later, the ratio D2 / L2 of the inner diameter D2 and the length L2 of the pipe 8a is 0.
The dimensions are determined within the range of 09 to 0.19.

Next, the operation of the pulse air ejection mechanism 3 based on the above configuration will be described. The high-pressure compressed air supplied to the header pipe 4 becomes pulse air by the action of the pulse valve 6 operated by an external signal, is transmitted to the nozzle 7 (or the nozzle 8) through the blow tube 5, and from the tip thereof. Is ejected. The pulsed air is transmitted to the inside of the filter cloth 2 through the opening 2a provided directly below the nozzle 7 (or the nozzle 8), vibrates the filter cloth 2 and blows through the filter cloth 2 to adhere to the filter cloth 2. The dust that is present can be removed. At this time, the nozzle 7 and the nozzle 8 are optimum to be able to reduce the pulse sound generated at the time of jetting pulsed air while maintaining the dust sweeping performance by pulsed air, based on the result of the comparison experiment with the nozzle of the conventional example. Since the shape is such that the noise of the bag filter dust collector can be reduced.

Next, a performance confirmation experiment when the following three types of nozzles according to the present embodiment and the conventional example are mounted will be explained. 4 and 5 show the shape of the nozzle 7 (P-type nozzle) according to the first embodiment, and the inner diameter D1 is 41.6 m.
m, the length L1 is 100 mm, and the perforated plate 7b is attached to the tip. FIG. 7 shows the shape of the nozzle 8 (T-shaped nozzle) according to the second embodiment, which has an inner diameter D2 of 27.6 mm and a length L2 of 150 mm. The hole 5b has the same shape as the inner diameter D2. Furthermore, FIG.
Shows the shape of the conventional nozzle 9 according to the conventional example, and the inner diameter D3
Is 35.7 mm, the length L3 is 50 mm, and the hole 5c is formed smaller than the inner diameter D3. The experimental device is shown in FIG.
As shown in FIG. 4, the header valve 4 having the same structure as that of the above-mentioned embodiment and connected to a high-pressure compressed air source (not shown) has the pulse valve 6 and the blow tube 5 attached thereto. From the blow tube 5 extending in the direction perpendicular to the axis, one of the nozzles 7, 8 and 9 is attached at a predetermined pitch in the longitudinal direction, and pulse air can be discharged into the inside of the filter cloth 2. Has been done. The air pressure in the header pipe 4 is 2.2 kgf / cm ² , and the operating time of the pulse valve 6 is set to 0.1 sec per operation.
It is possible to measure the pulse air ejection amount. In addition, the filter cloth 2 hung below the nozzles 7, 8 and 9 is
A pressure sensor is provided, and the pressure sensor is connected to a recorder via a pressure gauge so that the pressure at each position in the depth direction of the filter cloth 2 can be measured. Furthermore, a sound level meter for measuring a pulse sound is provided at a position 1 m on the machine side of the experimental apparatus.

10 and 11 are diagrams showing the experimental results. FIG. 10 is a frequency analysis of a pulse sound generated when the conventional nozzle 9 is used, and at this time, the noise level near the nozzle was 128 dB (A). Also, FIG.
1 is a frequency analysis of a pulse sound generated when the nozzle 7 (P-type nozzle) and the nozzle 8 (T-type nozzle) according to the present embodiment are used. At this time, the noise level near the nozzle is 115 dB, respectively. (A), 116 dB (A)
Met. Therefore, it is about 12 to 13 dB (A) from the conventional example.
Is being reduced. In addition, comparing the frequency analysis results in both figures, the nozzle 8 has a peak at about 1000 Hz, while the nozzle 7 has a characteristic of having more high frequency components. It can be seen that the sound is easily reduced by the case 1 and the like. As a result, at the noise level measured at the position 1 m on the machine side of the bag filter dust collector, the transmission loss of the filter cloth 2 and the case 1 is added, and therefore, about 100 dB when the conventional nozzle 9 is used.
In contrast to (A), when the nozzle 7 or the nozzle 8 according to the present embodiment is used, the noise level can be reduced to about 85 dB (A) or less, and the noise value can be guaranteed. .. Also, the dust removal performance was better than that of the conventional nozzle. This is because the pulse air exerted around the filter cloth is strengthened due to the difference in the nozzle structure.

[0012]

As described above, in the bag filter dust collector according to the present invention, a pipe member having an inner diameter substantially the same as the hole diameter is vertically provided at a position concentric with the hole provided in the blow tube. Since a nozzle is formed by providing a perforated plate at the tip portion, or a pipe member is vertically installed at a position concentric with the hole provided in the blow tube and the ratio D / L of the length L to the inner diameter D of the pipe member. 0.09 to 0.19
Since the nozzles are configured in this range, it is possible to reduce the pulse sound generated during pulse air ejection while maintaining the dust-dispelling performance, so that it is possible to obtain the noise reduction effect inexpensively and reliably.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a bag filter dust collector according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a pulse air ejection mechanism according to the first embodiment of the present invention.

FIG. 3 is a sectional view taken along line AA of FIG.

FIG. 4 is a sectional view showing a nozzle according to the first embodiment of the present invention.

5 is a BB view of FIG. 4. FIG.

FIG. 6 is a plan view showing a perforated disk according to another embodiment.

FIG. 7 is a sectional view showing a nozzle according to a second embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a nozzle according to a conventional example.

FIG. 9 is a diagram illustrating an experimental device.

FIG. 10 is a diagram showing frequency analysis of experimental results.

FIG. 11 is a diagram showing frequency analysis of experimental results.

[Explanation of symbols]

 2 Filter cloth 3 Pulse air discharge mechanism 4 Header tube 5 Blow tube 6 Pulse valve 7,8,9 Nozzle 7a, 8a Pipe 7b Perforated disk

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Koide 6-1, Nanyo-dori, Minami-ku, Nagoya-shi, Aichi Tokai Plant Engineering Co., Ltd.

Claims (2)

[Claims] 1. A bag-shaped filter cloth is vertically installed to capture dust in passing air, and pulse air is introduced into the filter cloth through a tubular nozzle provided in a blow tube having a pulse valve. In a bag filter dust collector configured to blow off dust adhering to the filter cloth by discharging, a pipe member is hung vertically at a position concentric with the hole provided in the blow tube, and A bag filter dust collector characterized in that a perforated plate is provided at the tip of a pipe member to form the nozzle. 2. A bag-shaped filter cloth is vertically installed to capture dust in passing air, and pulse air is introduced into the filter cloth through a tubular nozzle provided in a blow tube having a pulse valve. In a bag filter dust collector configured to blow off dust adhering to the filter cloth by discharging, a pipe having an inner diameter substantially the same as the hole diameter at a position concentric with the hole provided in the blow tube. The member is vertically installed and the ratio D / L of the length L to the inner diameter D thereof is set to 0.
A bag filter dust collector characterized in that the nozzle is formed in a range of 09 to 0.19.