JP3471548B2 - Method and apparatus for collecting suspended particles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for collecting suspended particles devised so that only suspended particles such as oil mist and dust are collected from a gas containing such suspended particles. It relates to the device.

[0002]

2. Description of the Related Art As one of the devices for collecting suspended particles such as oil mist contained in a gas, for example, Japanese Patent Laid-Open No.
There is a suspended particle collecting apparatus using ultrasonic waves as described in Japanese Patent Publication No. 47346.

This collecting device, as shown in FIG.
Hollow duct tube E into which gas containing suspended particles is introduced
And a cylindrical shape whose size is determined so that the sound field formed inside the duct pipe E becomes a strong standing wave state when it resonates at its natural frequency. It is composed of a vibrating body D, a horn B capable of resonating the vibrating body D at a natural frequency and emitting an ultrasonic wave, and an ultrasonic transducer A having a resonance rod C.

The dimensions of the cylindrical vibrating body D are calculated based on the respective mathematical expressions described in the right column of page 4 of the above publication, and the ideal dimensions (radius r, The thickness h, the total length) is as shown in FIG. 3 of the publication, and the shape of the vibrating body D may be rectangular (rectangular) in addition to the cylindrical shape described above. There is
This is as described on page 6, third embodiment of the above publication and FIG. 11.

[0005]

In the above-mentioned conventional collecting device, the sound pressure of the suspended particles in the gas emitted from the vibrating body D is reduced.
Excited by powerful ultrasonic waves of 160 dB or more ,
This excitation causes the particles to collide with each other and agglomerate to form a larger aggregate of suspended particles (for example, about 50 μm), which makes it possible to collect the particles with almost no pressure loss due to the action of gravity or the like. However, in the case of a device for colliding and aggregating suspended particles using ultrasonic waves in this way, the larger the number of suspended particles, the better the collection effect, and conversely, the number of suspended particles. If the amount is small, that is, if the dust concentration is small, the chances of the floating particles colliding with each other are small, so that there is a problem that the collection effect (efficiency) is deteriorated.

That is, the gas containing suspended particles introduced from one direction by being pushed or sucked by a blower (blower) passes through in the other direction (exhaust side) while undergoing the aggregation action by ultrasonic vibration. However, if the number of airborne particles contained in this gas is so small that the collection effect does not increase, there is still the problem that dirty gas containing airborne particles is discharged to the exhaust side. It was

Therefore, the technical problem of the present invention is that when the airborne particles in the gas are aggregated and collected by the ultrasonic vibration, even if the number of the airborne particles in the gas is small, the opportunity for the airborne particles to aggregate with each other. To increase the collection efficiency.

[0008]

[Means for Solving the Problems] Means taken in the present invention for solving the above technical problems are as follows.

A cylindrical vibrating body whose dimensions are determined so that the sound field formed therein becomes a standing wave state when it resonates at its natural frequency, and this vibrating body at a natural frequency. By using an ultrasonic wave generation source composed of an ultrasonic vibrator that resonates and emits ultrasonic waves, the suspended particles flowing inside the cylindrical vibrator are excited by the ultrasonic waves emitted from the vibrator. In the collecting method and the device that aggregate by

[0010] The (1) pushing action or a gas containing suspended particles undergoing suction effect is introduced from opposite sides, collide with the interior of cylindrical vibrator to emit said ultrasonic, suspended particles To agglomerate.

(2) A large number of air outlets from which the colliding fluid blows out on the peripheral surface of the middle portion of the flow pipe where the gas containing suspended particles introduced from both sides of the flow pipe upon receiving the pushing action or suction action collides. while bored, that surround the flow pipe bored this outlet vibration of cylindrical radiating the ultrasonic.

(3) A large number of air outlets from which the colliding gas blows out on the peripheral surface of the middle portion of the flow pipe where the gas containing suspended particles introduced from both sides of the flow pipe upon receiving the pushing action or the suction action collides. while bored, on the inner side of the intermediate portion of the flow tube where the gas collide, placing a vibrator cylindrical emit the ultrasonic waves.

When a resonator resonates at its natural frequency, a rectangular vibrating body whose dimensions are determined so that the sound field formed around it becomes a standing wave state, and this vibrating body at its natural frequency By using an ultrasonic wave generation source configured with an ultrasonic vibrator that resonates and emits ultrasonic waves, suspended particles flowing near the rectangular vibrator are excited by ultrasonic waves emitted from the vibrator. In the ultrasonic collection method and the device that aggregate by

[0014] (4) push the gas containing suspended particles that act or receiving suction is introduced from opposite sides, suspended particles collide near the rectangular vibrator which emits the ultrasonic To agglomerate.

(5) A large number of outlets through which the collided gas blows out on the peripheral surface of the intermediate portion of the flow pipe where the gas containing suspended particles introduced from both sides of the flow pipe upon collision with the pushing action or suction action collides. while bored, on the inner side of the intermediate portion of the flow tube where the gas collide, placing a rectangular vibrator for emitting the ultrasonic.

(6) The gas blown out from a large number of outlets formed in the middle portion of the flow pipe is circulated and convected to both ends of the flow pipe again by the pushing action or suction action of the blower, and the flow pipe Introduced from both sides toward the center, and configured to repeat the collision.

According to the means of claim 1 described in the above (1), since the fluid containing suspended particles such as oil mist is introduced from both sides opposite to each other and collided with each other, there is an opportunity of collision of suspended particles. While increasing and promoting aggregation, suspended particles that have undergone the aggregation effect due to collision are further ultrasonically radiated and are acoustically aggregated, so even if the gas contains a small number of suspended particles, the suspended particles are separated from each other. It increases the chances of aggregation and makes it possible to exert a high collection effect.

According to the means of claim 2 described in the above (2), the gas containing the suspended particles introduced from both sides of the flow pipe collides with each other in the middle portion of the flow pipe to agglomerate the suspended particles. On the other hand, since the gas blown out from the air outlet provided on the peripheral surface after the collision receives ultrasonic waves and further agglomerates the suspended particles with each other, even if the gas contains a small number of suspended particles. It is possible to increase the chances of floating particles to aggregate with each other and to exert a high collection effect.

According to the third aspect of the invention described in (3) above, the gas containing the suspended particles introduced from both sides of the flow pipe collides with each other in the middle portion of the flow pipe to agglomerate the suspended particles. At the same time, the ultrasonic waves are further agglomerated by receiving ultrasonic waves, so the chances of agglomeration increase and a considerable number of suspended particles are agglomerated at the time of being blown out from the outlet of the flow pipe. Therefore, even if the gas contains a small number of suspended particles, it is possible to exhibit a high trapping effect.

Claims 4 and 5 described in (4) and (5) above.
According to the means related to the above, by using the vibrating body entirely made in a rectangular shape, it is possible to exhibit the same excellent ultrasonic aggregating action as when using the vibrating body made entirely in a cylindrical shape. Even in the case of a gas containing a small number of suspended particles, it is possible to increase the chances of the suspended particles to aggregate with each other and to exhibit high aggregation efficiency.

According to the means of claim 6 described in the above (6), since the suspended particles repeatedly pass through the apparatus according to the circulating convection method, the suspended particles repeatedly have a chance of aggregating, which results in the aggregation effect. Enables further improvement.

As described above, the above (1)-
By solving the technical problem described above by means of (6),
It is possible to solve the problems of the conventional technology.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the above-described method for collecting suspended particles and an apparatus therefor according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram for explaining the structure of a so-called push-type collecting device which is an example of the collecting device according to the present invention. In FIG. 1, 1A and 1B are flow pipes 2 (pipes or pipes formed in a circular cross section). With the left and right blowers (blowers) attached to both ends of the duct, the gas containing suspended particles such as oil mist generated from the machine tool is distributed by the left and right blowers 1A and 1B as shown by the arrows. It is configured such that the particles are respectively pushed into the inside from the opposite end openings of the above, and collide with each other in the intermediate portion 2S so that the floating particles collide and aggregate.

Reference numerals 2A, ... Are blowout ports formed in a large number on the peripheral surface of the intermediate portion 2S of the flow pipe 2 where the gas introduced from opposite sides collides, and the suspended particles are caused by collision and mixing at the intermediate portion 2S. The gas obtained by colliding and agglomerating with each other is blown out to the outside of the flow pipe 2 through the blowout ports 2A ...

Reference numeral 4 denotes a cylindrical vibrating body mounted so as to surround the middle portion 2S of the flow pipe 2, that is, the periphery of the portion where the air outlets 2A ... Are bored, and the vibrating body 4 itself. The respective dimensions (radius, wall thickness, and total length) of the above-mentioned Japanese Patent Laid-Open No. 6-47346 are so arranged that the sound field formed therein becomes a strong standing wave state when resonating at the natural frequency. Since the dimensions are shown in the table of FIG. 3 of the publication, based on the mathematical formulas described on the page, a detailed description thereof will be omitted here.

Further, 5 is an ultrasonic vibrator (driver) for generating ultrasonic vibration, and 5a and 5b are the ultrasonic vibrators 5.
A horn and a resonance rod for transmitting the ultrasonic vibration from the vibration body 4 to the vibration body 4, and the tip of the resonance rod 5b is screwed to the side surface of the vibration body 4 with a nut 5c. The ultrasonic wave generator 5 and the horn 5a constitute an ultrasonic wave generation source.

Reference numerals 6 and 7 denote a generator and an amplifier connected to the ultrasonic transducer 5, the amplifier 7 amplifies the drive signal from the generator 6, and the generator 6 filters back the vibration frequency from the horn 5a. , Equipped with a frequency controller that keeps this within a certain range.

When the ultrasonic transducer 5 is driven through the generator 6 and the amplifier 7 in the above structure,
The ultrasonic waves generated by the vibrator 5 are transmitted to the vibrating body 4 via the horn 5a, and the vibrating body 4 resonates so that bending vibration predominantly occurs in the circumferential direction of the vibrating body 4, so that the vicinity of the vibrating body 4 is vibrated. The gas is accelerated by the vibrating body 4 to emit an ultrasonic wave, and the ultrasonic field emitted from the vibrating body 4 causes a sound field formed in the cylindrical vibrating body 4 to be in a resonance state. Although it is configured to generate ultrasonic waves of high sound pressure that cannot be obtained by an ultrasonic source, and to excite the gas blown out from each of the outlets 2A of the flow pipe 2 and the suspended particles contained therein. The specific structure for exciting the suspended particles is as described in the specification and the drawings of JP-A-6-47346, and the description thereof is omitted here.

The suspended particles excited as described above collide with each other and are ultrasonically aggregated to form a larger aggregate of suspended particles, which are recovered by the action of gravity or the like. And the gas containing suspended particles that can not be aggregated to a sufficient size even when subjected to this ultrasonic agglomeration,
As shown by the arrow in FIG. 1, the air is circulated to the left and right blowers 1A and 1B, and is introduced into the flow pipe 2 from both sides again, and the collision agglomeration and the ultrasonic agglomeration of suspended particles are repeated. It can be significantly improved.

In the figure, 3A and 3B are straw filters installed in the left and right mouth portions of the above-mentioned flow pipe 2,
Each of these straw filters 3A and 3B is formed by arranging a plurality of elongated passages by binding a plurality of (for example, about 200) elongated straw-shaped hollow tubes into a substantially columnar shape. The gas introduced into the inside of the flow pipe 2 by the left and right blowers 1A, 1B is first of all the blowers 1
Stirred by the A and 1B impellers (blades) to agglomerate the suspended particles, and then the straw filters 3
Similarly, the particles are adhered and agglomerated by passing through the elongated passages A and 3B, and then the above-described collisional agglomeration and ultrasonic agglomeration are performed, so that the floating particles adhere and agglomerate repeatedly.

FIG. 2 is a block diagram for explaining the structure of a so-called suction type collecting device which is another example of the collecting device according to the present invention. In this suction type collecting device, the left and right ends of the flow pipe 2 are provided. While the suction ports 10A and 10B having wide openings are attached, substantially the entire flow pipe 2 including the cylindrical vibrating body 4 is provided on one side with a dust collection box 13 having a blower 13T (blower) for suction. In the structure described above, the gas containing suspended particles is sucked and introduced into the inside of the flow pipe 2 from the left and right suction ports 10A and 10B by the suction operation of the blower 13T. The gas is exhausted from the blower 13T and is circulated and convected again to the left and right suction ports 10A and 10B to collect the particles by collision aggregation and ultrasonic aggregation, and the above aggregation is repeated.

In FIG. 2, the same members as those in FIG. 1 are designated by the same reference numerals as those in FIG. 1, and the description thereof will be omitted.

FIG. 3 is a block diagram for explaining the structure of another example of the present invention which can be applied to both the pushing type and suction type collecting devices described above. In the collecting device shown in FIG. The vibrating body 4 formed in a circular shape is attached to the inside of the intermediate portion 2S of the flow pipe 2, and the suspended particles introduced from both sides and collided are vibrated by ultrasonic waves on the spot, so that the suspended particles are separated from each other. Collision efficiently and ultrasonic agglomeration are efficiently performed inside the intermediate portion 2S, and the suspended particles that have become large due to these two agglomerations are blown out together with the gas from the outlet 2A to the outside of the flow pipe 2, It is configured to be recovered by the action of gravity or the like.

FIG. 4 shows a vibrating body 4 formed in a rectangular shape (rectangular shape) in place of the cylindrical vibrating body 4 shown in FIG.
The other structure of the present invention, in which X is provided in the intermediate portion 2S of the flow pipe 2 in which the gas introduced from the left and right collides, is described. That is, by further ultrasonically aggregating inside the flow pipe 2, the chance of aggregating is increased and the aggregating effect is enhanced.

The method of collecting suspended particles and the apparatus therefor according to the present invention are as described above, and the gas introduced by the pushing action or the suction action from both sides of the flow pipe 2 is collided to form the gas. Since the floating particles contained in the particles are first subjected to collision agglomeration and then ultrasonic wave agglomeration is applied thereto, the chances of the floating particles agglomerating can be increased and an excellent collection effect can be exhibited.

Therefore, the collection device according to the present invention is installed directly in the machine room where machine tools or the like are installed, or
If it is installed outside the machine room through each of the introduction and exhaust circulation ducts (pipes), the gas containing suspended particles can be circulated repeatedly between the machine room and the equipment, increasing the chance of aggregation. Therefore, it is possible to collect suspended particles in the working room without polluting the surrounding environment, and it is possible to exhibit an excellent collection effect even if the number of suspended particles in the gas is small. There is.

[0038]

As described above, according to the method of collecting suspended particles and the apparatus therefor according to the present invention, particularly for an air stream having a small number of suspended particles in the gas, that is, an air stream having a low dust concentration. In addition, it is possible to exert an excellent collection effect, and furthermore, even if the suspended particles do not aggregate to a size such that they can settle by gravity, they can be reliably collected by giving an opportunity of aggregation, which is safe and cost-effective. Able to collect cheap dust.

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating a structure of a push-type collection device which is an example of a collection device according to the present invention.

FIG. 2 is a configuration diagram illustrating the structure of a suction type collecting device which is another example of the collecting device according to the present invention.

FIG. 3 is a front sectional view showing a main part of an apparatus according to the present invention applicable to both a push-in type suction apparatus and a suction-type collecting apparatus.

FIG. 4 is a configuration diagram illustrating a usage example of a vibrator formed in a rectangular shape.

FIG. 5 is a perspective view illustrating the structure of a conventional ultrasonic collection device.

[Explanation of symbols]

1A, 1B, 13T blower 2 distribution pipes 2A outlet 2S middle part 4,4X vibrating body 5 Ultrasonic transducer 5a horn

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B01D 51/08 B01D 51/02 B01D 46/24 B06B 1/06

Claims (6)

(57) [Claims] 1. A cylindrical vibrating body whose dimensions are determined so that the sound field formed therein becomes a standing wave state when it resonates at its natural frequency, and the vibrating body is unique. By using an ultrasonic wave generation source configured with an ultrasonic vibrator that resonates at a frequency and emits ultrasonic waves, the ultrasonic particles emitted from the vibrating body can be used to generate suspended particles flowing inside the cylindrical vibrating body. while excited to aggregate, the gas containing suspended particles introduced from opposite sides receiving the pushing action or sucking action, collide with the interior of the cylindrical vibrator to emit the ultrasonic waves suspended particles A method for collecting suspended particles, comprising: 2. A cylindrical vibrating body, the dimensions of which are determined so that the sound field formed therein becomes a standing wave state when it resonates at its natural frequency. By using an ultrasonic wave generation source configured with an ultrasonic vibrator that resonates at a frequency and emits ultrasonic waves, the ultrasonic particles emitted from the vibrating body can be used to generate suspended particles flowing inside the cylindrical vibrating body. While being configured to be excited and aggregated, the colliding fluid blows on the peripheral surface of the middle portion of the flow pipe where gas containing suspended particles introduced from both sides of the flow pipe due to the pushing action or suction action collides. suspended particles bored a number of air outlet, and, to the periphery of the flow pipe bored this outlet, characterized in that enclosed by vibrator cylindrical emits above <br/> ultrasonic issue Collection device. 3. A cylindrical vibrating body whose dimensions are determined so that the sound field formed therein becomes a standing wave state when it resonates at its natural frequency, and the vibrating body By using an ultrasonic wave generation source configured with an ultrasonic vibrator that resonates at a frequency and emits ultrasonic waves, the ultrasonic particles emitted from the vibrating body can be used to generate suspended particles flowing inside the cylindrical vibrating body. While being configured to be excited and aggregated, the colliding gas blows on the peripheral surface of the middle portion of the flow pipe where the gas containing suspended particles introduced from both sides of the flow pipe due to the pushing action or the suction action collides. suspended particles bored a number of air outlet, and, inside the middle portion of the flow pipe in which the gas collides, characterized in that allowed placing vibrator cylindrical emit said ultrasonic issuing Collection device. 4. A rectangular vibrating body, the dimensions of which are determined so that the sound field formed around the vibrating body becomes a standing wave state when it resonates at its natural frequency, and the vibrating body is unique. By using an ultrasonic wave generation source configured with an ultrasonic vibrator that resonates at a frequency and emits ultrasonic waves, the ultrasonic particles emitted from the vibrating body cause floating particles flowing near the rectangular vibrating body to be emitted. while excited to aggregate, the gas containing suspended particles introduced from opposite sides receiving the pushing action or sucking action, to collide near the rectangular vibrator which emits the ultrasonic waves suspended particles A method for collecting suspended particles, comprising: 5. A rectangular vibrating body whose dimensions are determined so that a sound field formed around the vibrating body becomes a standing wave state when it resonates at a natural frequency, and the vibrating body is unique. By using an ultrasonic wave generation source configured with an ultrasonic vibrator that resonates at a frequency and emits ultrasonic waves, the ultrasonic particles emitted from the vibrating body cause floating particles flowing near the rectangular vibrating body to be emitted. While being configured to be excited and aggregated, the colliding gas blows on the peripheral surface of the middle portion of the flow pipe where the gas containing suspended particles introduced from both sides of the flow pipe due to the pushing action or the suction action collides. suspended particles bored a number of air outlet, and, inside the middle portion of the flow pipe in which the gas collides, characterized in that allowed placing rectangular vibrator which emits the ultrasonic issuing Collection device. 6. The gas blown from a large number of outlets formed in the middle of the flow pipe is circulated and convected to both ends of the flow pipe by being pushed or sucked by a blower, so that both sides of the flow pipe are closed. 6. The airborne particle collecting apparatus according to claim 2, wherein the airborne particle collecting apparatus is configured to be introduced again toward the central portion and repeat collision.