KR20200008318A - Apparatus and method for removing particulate matters by using ultrasound and coagulant - Google Patents

Abstract

According to one embodiment of the present invention, disclosed is an apparatus for removing fine particles, designed to remove fine particles from gas. The apparatus for removing fine particles comprises: a flocculant injection unit injecting a flocculant into gas containing fine particles; an ultrasonic agglomeration unit applying ultrasonic waves to the gas passing through the flocculant injection unit to aggregate the fine particles in the gas; and a dust collection unit configured to collect the aggregated fine particles from the gas passing through the ultrasonic agglomeration unit to remove the fine particles.

Description

Apparatus and method for removing particulate matters by using ultrasound and coagulant}

The present invention relates to a microparticle removal device and a method for removing microparticles from a gas, and more particularly, to remove microparticles existing in a gas such as exhaust gas, waste gas or air using ultrasonic waves and a flocculant. And a removal device and method.

In a device or facility in which fine particles are generated, such as a power plant or an internal combustion engine, a dust collecting device for removing the fine particles is essentially disposed. Generally, an electrical dust collecting device or a mechanical dust collecting device is used.

Recently, techniques using ultrasonic waves for collecting fine particles have been studied. When ultrasonic waves are applied to the gas containing the microparticles, the gas is divided into a dense region and a small region, and the microparticles are collected in the dense region, and the microparticles can be removed more efficiently in the state in which the microparticles are aggregated.

However, in the case of ultrasonic dust collection, even if agglomerates the microparticles by applying ultrasonic waves to the microparticles, the cohesion force is not high. Therefore, when the flow is applied to the agglomerated particles, the particles tend to be redispersed. In one case, there is a problem that the dust collecting effect is not high.

Patent Document 1: Korean Patent Publication No. 2003-0057582 (published Jul. 7, 2003)

The present invention is designed to solve the above problems, and aims to improve the dust-collecting effect of the fine particles by further increasing the effect of fine particle aggregation when using ultrasonic waves.

According to one embodiment of the present invention, a fine particle removal device for removing fine particles from the gas, the flocculant injection unit for injecting a coagulant into the gas containing the fine particles; An ultrasonic agglomeration unit for applying ultrasonic waves to the gas passing through the flocculant injection unit to aggregate fine particles in the gas; And a dust collecting unit for collecting and removing the aggregated fine particles from the gas passing through the ultrasonic flocculating unit.

In one embodiment, the flocculant inlet may be configured to spray the flocculant of solid or liquid toward the gas in the form of droplets or aerosols.

According to one embodiment of the invention, a method for removing microparticles to remove microparticles from a gas, comprising: injecting a flocculant into a gas containing microparticles; Applying ultrasonic waves to the gas into which the flocculant is injected to aggregate the fine particles in the gas; And collecting the aggregated fine particles to remove them from the gas.

In one embodiment, injecting the flocculant may comprise injecting a flocculant of a solid or liquid towards the gas in the form of droplets or aerosols.

According to the present invention, by applying an ultrasonic wave to a gas mixed with fine particles and a flocculant to agglomerate the fine particles, even when the aggregated particles are impacted by an external force such as flow, the aggregated particles are not redispersed so as to maintain the aggregates. There is an effect that can be improved.

1 is a block diagram of a microparticle removal device according to an embodiment of the present invention;
2 is a view for explaining a microparticle removal apparatus according to an embodiment;
3 is a view for explaining the effect of removing the fine particles using ultrasonic and flocculant,
4 is a view for explaining the dust collection efficiency according to the particle size.

The above objects, other objects, features and advantages of the present invention will be readily understood through the following preferred embodiments associated with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the invention to those skilled in the art.

In the present specification, where a component is mentioned as being on another component, it means that it may be formed directly on the other component or a third component may be interposed therebetween. In addition, the thickness of the components in the drawings are exaggerated for effective explanation of the technical content.

Where the terms first, second, etc. are used herein to describe the components, these components should not be limited by these terms. These terms are only used to distinguish one component from another. The embodiments described and illustrated herein also include complementary embodiments thereof.

In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, the words "comprise" and / or "comprising" do not exclude the presence or addition of one or more other elements.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In describing the specific embodiments below, various specific details are set forth in order to explain and understand the invention in more detail. However, one of ordinary skill in the art can understand that the present invention can be used without these various specific details. In some cases, it is mentioned in advance that parts of the invention that are commonly known and do not relate to the invention are not described in order to avoid confusion in describing the invention.

1 is a block diagram of a microparticle removal apparatus according to an embodiment of the present invention.

The microparticle removal apparatus of the present invention can be applied to any technical field for removing microparticles from a gas. For example, the apparatus for removing microparticles according to an embodiment of the present invention may be a combustion facility such as an internal combustion engine that discharges particulate matter, a power plant, etc., a workplace or a production facility where a lot of fine dust is generated, or an air cleaner. It can be applied to any device or facility.

In addition, the microparticles to be removed of the microparticle removal apparatus of the present invention is any particulate matter having a size of 0.1 to 1.0 micrometer (μm), and may mean any one of fine particles, fine dust, dust, and fly ash. In the following description, the term " microparticles "

Referring to FIG. 1, the apparatus for removing microparticles according to one embodiment may include a flocculant injection unit 10, an ultrasonic flocculation unit 20, and a dust collecting unit 30. Gases containing fine particles (eg, air, exhaust gas, waste gas, etc.) are transported in order to pass through the flocculant injection unit 10, the ultrasonic flocculation unit 20, and the dust collecting unit 30, as indicated by arrows in the drawing. Fine particles in the gas are agglomerated and collected and removed.

The flocculant injection unit 10 injects a flocculant into the gas. The flocculant can be a liquid or solid substance of any component capable of flocculating the microparticles. In one embodiment, water may be used as flocculant, and any liquid or solid material that enhances cohesion may be added to the water as needed. Alternatively, the flocculant may be in the form in which fine particles of cohesive solid are dispersed or degraded in solution.

The ultrasonic flocculation unit 20 agglomerates microparticles in the gas by applying ultrasonic waves to the gas passing through the flocculant injection unit 10. When the ultrasonic wave is applied to the gas, the gas is divided into a dense area and a small area by the ultrasonic wave, and the fine particles are collected in the dense area. (Hereinafter referred to as "aggregate").

As described above, agglomerates of larger diameters may be made by agglomeration of the fine particles in the ultrasonic agglomeration unit 20. In this case, according to the present invention, since the flocculant promotes and maintains the flocculation of the fine particles, the aggregate is not redispersed (decomposed) while the aggregate is discharged from the ultrasonic flocculation unit 20 and transported to the dust collector 30. I can keep it.

The gas passing through the ultrasonic agglomeration unit 20 is transferred to the dust collecting unit 30, and the dust collecting unit 30 collects and removes the fine particles in the gas. At this time, since the fine particles continue to maintain the aggregate form by the action of the flocculant, the fine particles can be collected more effectively than in the prior art. The specific dust collecting method of the dust collecting unit 30 may vary depending on the embodiment. For example, a method of removing (gravitation settling) by the self-weight of the aggregate may be used, and in addition, one or a combination of dust collectors such as cyclones, filters, and electrostatic precipitators may be used.

Meanwhile, although not shown in FIG. 1, an apparatus for filtering large particles may be further added to the front end of the coagulant injector 10. That is, a filtering device such as a cyclone or an electrostatic precipitator may be disposed at the front end of the coagulant injector 10 in order to primarily remove particles that are relatively larger than fine particles. By doing so, it is possible to perform dust collection and removal of fine particles more effectively.

2 is a view for explaining the microparticle removal apparatus according to an embodiment in more detail. For convenience of description, only the flocculant injection unit 10 and the ultrasonic flocculation unit 20 are schematically illustrated in FIG. 2, and the dust collecting unit 30 is omitted.

Referring to the drawings, the coagulant injecting unit 10 may include a storage unit 11, the transfer pipe 12, and the injection nozzle (13). The storage unit 11 is a tank for storing the flocculant. The flocculant stored in the storage unit 11 may be transferred to the injection nozzle 13 through the transfer pipe 12. In the injection nozzle 13, the flocculant is injected into the gas delivery pipe 110. More components, such as a pump, may be needed to transfer the flocculant, but are not shown for convenience of description.

In one embodiment, the flocculant may be a liquid or a solid of any component capable of flocculating the microparticles, and in alternative embodiments, the flocculant solid particles may be in a dispersed or degraded form in a solution. When the injection nozzle 13 injects the flocculant into the conveying pipe 110, it may be configured to spray the liquid or solid flocculant in the form of droplets or aerosols. At this time, the droplets of the flocculant sprayed or the size of the aerosol (diameter) is preferably a size similar to the size of the fine particles to be removed.

In order to spray the flocculant into the fine droplets or aerosol through the injection nozzle 13, a technique such as an electrospray method or ultrasonic vibration may be used, and thus the description thereof will be omitted.

The ultrasonic agglomeration unit 20 agglomerates fine particles in the gas by applying ultrasonic waves to the gas. In the illustrated embodiment, the ultrasonic agglomerate 20 includes a chamber 250 and one or more ultrasonic generators 210, 220, 230, and 240 disposed on one side of the chamber.

The chamber 250 is a space for receiving the gas transferred to the ultrasonic agglomeration part 20 through the transfer pipe 110. The diameter of the chamber 250 may be the same as or larger than the conveying piping 110. The chamber 250 may be cylindrical or cylindrical having a polygonal cross section such as a square pillar.

The ultrasonic generators 210, 220, 230, and 240 are arranged in one line on one side of the chamber 250 to generate ultrasonic waves, respectively, and the generated ultrasonic waves are transmitted toward the inside of the chamber 250. Although four ultrasonic generators 210, 220, 230, and 240 are illustrated in the drawing, the number of ultrasonic generators may vary according to specific embodiments. However, when installing a plurality of ultrasonic generators may be arranged at regular intervals along the longitudinal direction of the chamber (that is, the gas transport direction).

Since the principle of ultrasonic generation or the specific structure of the ultrasonic generator are well known techniques, description thereof will be omitted. In the drawing, each of the ultrasonic generators 210, 220, 230, and 240 includes ultrasonic vibration units 211, 221, 231, and 241. The ultrasonic vibration units 211, 221, 231, and 241 may be formed in a circular (or polygonal, rectangular) plate that is formed toward the interior of the chamber 250 and may vibrate at a frequency corresponding to ultrasonic waves. Accordingly, for example, when the ultrasonic generators 210, 220, 230, and 240 generate vibrations of ultrasonic frequencies, the ultrasonic vibration units 211, 221, 231, and 241 may amplify the ultrasonic waves by the vibration and transmit the ultrasonic waves into the chamber 250.

As shown in the figure, in one embodiment, the ultrasonic vibration units 211, 221, 231 and 241 are arranged to transmit ultrasonic waves in a direction perpendicular to the transport direction of the gas. The transmitted ultrasonic waves are reflected from the surfaces 251 facing the ultrasonic generators 210, 220, 230, and 240 in the chamber 250, and are returned to the ultrasonic generators 210, 220, 230, and 240. It may be desirable for the distance to be a multiple of the ultrasonic wavelength. As a result, the wavelengths of the ultrasonic waves reflected and propagated between the ultrasonic generators 210, 220, 230, 240 and the opposing surface 251 are overlapped and efficiently generate small areas and small areas, and fine particles in the gas are dense. Are gathered. The fine particles gathered in the dense region are promoted to be aggregated by the coagulant to form agglomerates (that is, aggregates), and in this state, the fine particles are transferred to the dust collecting unit 30 through the gas transfer pipe 120.

Figure 3 shows the effect of removing the fine particles by using the ultrasonic wave and the flocculant of the present invention in comparison with the prior art, Figure 3 (a) is not using a flocculant and Figure 3 (b) is a flocculant The microparticle agglomeration operation when using is schematically shown.

First, referring to FIG. 3 (a), the gas introduced into the ultrasonic conveying unit 20 through the conveying pipe 110 is agglomerated in a dense area by ultrasonic waves transmitted from the ultrasonic generators 210, 220, 230, and 240 to form an aggregate. The aggregate is discharged from the ultrasonic aggregate 20 through the transfer pipe 120 and is transferred to the dust collecting unit 30. However, ultrasonic waves are not applied to the path through which the aggregates are transferred through the transfer pipe 120. When the aggregates are subjected to an external force by the flow or turbulence of the gas, the aggregates are dispersed.

However, in the embodiment of the present invention of Figure 3 (b) can solve the above problems. As shown in FIG. 3 (b), when the coagulant is supplied to the delivery pipe 110 through the injection nozzle 13 of the coagulant injecting unit 10, the fine particles and the coagulant are transferred together to the ultrasonic agglomeration unit 20, and the ultrasonic wave is ultrasonic. By the flocculation agent when the fine particles are aggregated by the aggregation phenomenon is activated and promoted.

At this time, it is preferable to use a flocculant of the same size or similar to the size of the fine particles in order to smoothly occur the above-described aggregation phenomenon in the ultrasonic flocculation unit 20. For example, when the size of the microparticles to be aggregated is between 0.1 and 1.0 μm, the droplets or aerosols of the flocculant sprayed through the injection nozzle 13 are preferably sprayed with the same or similar size. In this case, since the fine particles and the coagulant move in a similar behavior, the fine particles and the coagulant may be uniformly mixed, and the fine particles may be harder and densely aggregated around the coagulant.

In one embodiment, the agglomeration phenomenon as described above in the ultrasonic agglomeration part 20 may form an agglomerate having a diameter of several times or more, for example, of fine particles. Since the fine particles in the aggregates are tightly and densely aggregated by the coagulant, the aggregates can be maintained without being dispersed while the aggregates are discharged from the ultrasonic agglomerate 20 and transferred to the dust collector 30, and the dust collector 30 is collected. The dust collection effect at) can be further enhanced.

4 is a graph illustrating dust collection efficiency according to particle size. In the graph, the horizontal axis represents the size (diameter) of the fine particles and the vertical axis represents the dust collection efficiency.

According to the graph, in general, when the microparticle diameter is 0.1 μm or less, dust may be collected by a diffusion method, and when the microparticle diameter is 0.5 μm or more, it may be collected by an inertial collision or the like. However, when the particle diameter is between 0.1 and 0.5 μm, neither diffusion nor inertia collision is effective, so the dust collection efficiency is low. Even when the diameter is between 0.5 and 1.0 μm, the dust collection method is preferable, but the dust collection efficiency itself is not high. It can be seen that.

However, when the microparticle removal device according to the present invention is used for the microparticles between 0.1 to 1.0 μm of low dust collection efficiency, the dust collection efficiency may be increased. That is, microparticles having a diameter of 0.1 to 1.0 μm may be made into aggregates of at least 0.5 μm or more, preferably 1.0 μm or more by using a flocculant and ultrasonic waves, and the aggregates may be kept from being dispersed until the dust collecting part 30 is reached. . Therefore, in the dust collecting part 30, the aggregate can be removed with high efficiency by, for example, an inertial collision or the like. Therefore, according to the present invention, the fine particles can be removed with high efficiency even for the microparticles having a low dust collection efficiency of 0.1 to 1.0 μm.

As such, those skilled in the art will understand that various modifications and variations are possible from the description of this specification. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below but also by the equivalents of the claims.

10: flocculant injection unit
20: ultrasonic flocculation unit
30: dust collector

Claims (9)

A microparticle removal device for removing microparticles from a gas,
Coagulant injecting unit 10 for injecting a coagulant into the gas containing the fine particles;
Ultrasonic agglomeration unit 20 to agglomerate the fine particles in the gas by applying ultrasonic waves to the gas passing through the flocculant injection unit; And
And a dust collecting unit (30) for collecting and removing the aggregated fine particles from the gas passing through the ultrasonic flocculating unit. The method of claim 1,
The flocculant injection unit (10) is fine particles removal device, characterized in that configured to spray the solid or liquid flocculant toward the gas in the form of droplets (droplets) or aerosols. The method of claim 1, wherein the ultrasonic flocculation unit 20,
A chamber 250 containing the gas; And
An ultrasonic generator disposed on one side of the chamber;
Ultrasonic waves generated by the ultrasonic generator is configured to be sent toward the inside of the chamber fine particles removal apparatus. The method of claim 3, wherein
The ultrasonic generator is composed of a plurality of ultrasonic generators 210, 220, 230, 240 arranged along the longitudinal direction of the chamber,
Each of the ultrasonic generators includes ultrasonic vibration units (211, 221, 231, 241) formed toward the inside of the chamber, wherein the ultrasonic wave generated by the ultrasonic generator is transmitted to the inside of the chamber through the ultrasonic vibration unit. The method of claim 4, wherein
Wherein each of the ultrasonic vibration units transmits ultrasonic waves in a direction perpendicular to the conveying direction of the gas, such that the aggregates are aggregated along the conveying direction of the gas. As a method for removing microparticles to remove microparticles from a gas,
Injecting a flocculant into a gas containing fine particles;
Applying ultrasonic waves to the gas into which the flocculant is injected to aggregate the fine particles in the gas; And
Collecting the aggregated fine particles to remove them from the gas. The method of claim 6,
The injecting the flocculant may include spraying the flocculant of the solid or liquid toward the gas in the form of droplets or aerosols. The method of claim 6,
The agglomeration of the microparticles is fine, characterized in that performed in the ultrasonic agglomeration unit 20 having a chamber for receiving the gas and a plurality of ultrasonic generators disposed along the conveying direction of the gas on one side of the chamber Particle removal method. The method of claim 8,
Wherein each of the generators transmits ultrasonic waves in a direction perpendicular to the direction of transport of the gas, such that the aggregates are aggregated along the direction of transport of the gas.

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