JPH0639774Y2 - Exhaust gas purification device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying apparatus for purifying exhaust gas containing fine mist and fumes as harmful components.

[0002]

2. Description of the Related Art In recent surface treatment processes for metals and semiconductors, acid cleaning liquids such as hydrochloric acid, sulfuric acid and nitric acid are often used for surface treatment in a high temperature bath. The present situation is that the vapor of the acidic gas is constantly discharged along with the exhaust gas.

Most of these exhaust gases have conventionally been treated in a relatively simple wet tower such as a packed tower or a porous tower.

[0004]

However, in the treatment by the wet cleaning tower described above, fine aerosol-like mist generated by the association of the moisture and the acid gas in the treatment tower is collected by the mist separator on the discharge side. It is not possible to do so, and there is a problem in terms of pollution, such as white smoke atomizing in the chimney, obstructing the field of view, and hanging up in the surrounding area.

In order to remove the aerosol that has been atomized into white smoke, there is no means for solving the problem except to additionally install a device having a high-performance dust removing function such as a high-performance filter or an electrostatic precipitator after the wet cleaning device. However, these require a new large installation space, and the costs such as the initial cost and running cost of the processing equipment are high, and it is easy to improve the existing exhaust equipment and to prevent pollution of the new exhaust equipment. Cannot be carried out.

Further, as a wet dust collector for treating a gas containing fine dust, there has been a conventional one in which a liquid is sprayed directly on a rotary blade of a blower. Is insufficient, and in order to treat the exhaust gas to the extent that the purification effect is sufficient, another wet cleaning method or the addition of an electrostatic precipitator was required.

The present invention has been made in view of the above points, and as a result of earnest research on means for treating exhaust gas containing acid gas which forms aerosol-like white smoke atomization that is difficult to remove, the conventional wet cleaning It is an object of the present invention to provide an exhaust gas purifying apparatus capable of treating the exhaust gas with high efficiency, which has been impossible by the method alone.

[0008]

Means for Solving the Problems The gist of the present invention for achieving the above-mentioned object is to provide a centrifugal rotary impeller provided in a spiral cylinder having a suction port and a discharge port for exhaust gas. An exhaust gas purifying apparatus characterized in that a cleaning liquid nozzle is arranged in front of the mouth, and a porous disc having a large number of small holes for forcibly passing and contacting the exhaust gas and the liquid sprayed from the cleaning liquid nozzle is arranged. It is in.

[0009]

[Operation] Exhaust gas is brought into contact with the liquid sprayed from the cleaning liquid nozzle before the suction port, and this gas-liquid mixture is sprayed over the perforated disk to forcefully pass it through. The centrifugal rotary impeller is sucked and mixed and stirred,
Absorbs and aggregates and removes harmful components in exhaust gas, and discharges clean gas from the discharge port.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of the exhaust gas purifying apparatus of the present invention.

The exhaust gas purifying apparatus of the present invention comprises a spiral cylinder 3 having an exhaust gas inlet 1, an exhaust gas discharge port 2, a centrifugal rotary impeller 4 rotatably disposed in the spiral cylinder 3, the exhaust gas. The cleaning liquid nozzle 5 is arranged in front of the suction port 1, and the perforated disk 7 has a large number of small holes 6 on the entire surface.

At least one cleaning liquid nozzle 5 is provided so as to face the porous disc 7 so that the liquid is sprayed onto the entire surface of the disc 7. As a method of spraying the cleaning liquid from the cleaning liquid nozzle 5, any means can be used as long as it is a means for producing a fine cleaning liquid, and a one-fluid nozzle for spraying only the cleaning liquid and a two-fluid for mixing compressed air and the cleaning liquid A nozzle, an ultrasonic fine particle nozzle, or the like can be used.

The porous disc 7 is provided in the suction port 1,
It is desirable to provide it in the smallest throttle portion where the gas passing wind speed becomes the highest in order to enhance the gas-liquid contact effect. The shape of the small hole 6 may be a round hole, an elliptical hole, a rectangular hole, an oblong hole or the like, but from the viewpoint of preventing clogging and low pressure loss, a round hole is preferable and the flow path resistance is reduced. For,
Taper or bellmouth shaped holes can also be used. The small holes 6 are preferably arranged at even intervals so that the gas and liquid are evenly dispersed on the entire surface of the disc 7.

For example, the gas flow rate through the small holes is 30 m.
/ Sec or more is preferable. The minimum size of the small hole 6 is 0.1-3
It is possible to use 0 mm and an aperture ratio of 5 to 50%, but considering static pressure loss and gas-liquid contact effect, 0.5 to 20 m
Those having m and an aperture ratio of 10 to 40% are preferable.

Further, as a constituent material of the porous disc 2, a corrosion resistant material such as plastic, metal, ceramic, glass or the like can be used. In addition to the processed plate material, a porous material obtained by sintering and laminating a small particle size material such as plastic, metal, ceramic, or glass, or a porous material having open cell voids can be used. As a gas-liquid contact material having a small flow path resistance, it is preferable to use a material obtained by laminating plastic with spherical spherical pearl polymer particles. Further, as the other plate material, it is possible to use a material in which fibers of the above-mentioned plastic, metal, ceramics, glass, etc. are formed in a net-like plane shape, or to be laminated in multiple layers or three-dimensionally knitted and have relatively uniform voids. it can.

Although not specifically shown, the centrifugal rotary impeller 4 is composed of a main plate, a sub plate, and a blade, has a well-known structure that sucks gas from the center of the impeller and discharges it in the centrifugal direction, and its blade shape is radial. It is possible to use radial blades, rearward blades, frontward blades, etc. that extend in the direction of the blade, but in order to prevent imbalance when the blades adhere, especially when adhering powder or impurities are entrained in the gas. Is desirable.

The spiral cylinder 3 may be either horizontal or vertical, but in order to facilitate the separation of gas and liquid, the spiral cylinder 3 is arranged vertically so that the discharge port 2 is provided so that the liquid flow does not become stagnant. It is desirable to have it face down or sideways.

In the above-mentioned structure, the exhaust gas containing the acidic gas flows in parallel with the liquid sprayed from the cleaning liquid nozzle 5 in the preceding stage of the suction port 1 of the spiral tube 3 while making gas-liquid contact with the porous disk 7. The small holes 6 of the circular plate 7 are sprayed over the entire surface.
Are forcibly passed through to be mixed and re-dispersed into fine droplets to absorb gas and agglomerate white smoke, and subsequently this gas-liquid mixture is sucked from the suction port 1 into the spiral tube body 3. . Since the centrifugal rotary impeller 4 rotates at a high speed in the spiral tube body 3, the gas-liquid mixed flow flows in the circumferential direction while being subjected to an extremely vigorous centrifugal rotation force to perform mixing and stirring. The harmful gas component is absorbed and the white smoke body is coagulated and grown, and the liquid component collecting the harmful component is separated by the mass difference from the gas component in the swirl chamber, and only the clean gas component is discharged from the discharge port 2. Liquid component is discharged as a liquid flow

[0020]

According to the present invention having the above structure, the following effects can be obtained.

(1) White smoke can be made inconspicuous by a chimney by removing with high removal efficiency exhaust gas containing an acidic component that atomizes white smoke, which cannot be completely removed by a conventional wet cleaning apparatus, and is therefore expensive. There is no need to add an electric dust collector, and the cost of pollution prevention measures is low, and the economic effect is extremely large.

Further, the porous disk immediately before the centrifugal rotary impeller has an effect similar to that of a multi-venturi to evenly disperse gas and liquid by violent mixing of gas and liquid, so that it is stable regardless of the size of the apparatus. It is possible to secure the required performance. Also, since the centrifugal rotary impeller is always washed with liquid,
Even if there is sticky dust in the gas, it can be washed away, imbalance due to powder adhesion can be prevented, and maintenance management is easy.

Further, the apparatus of the present invention can be provided with a wet washing tower for pretreatment when the concentration of the inlet is abnormally high in addition to being used alone, and the liquid droplets which cannot be separated in the cylinder are subsequently provided. By installing the Tori Eliminator,
The exhaust gas purification effect can be further enhanced.

(2) Not only the harmful gas components in the exhaust gas can be removed with high efficiency as compared with the conventional packed tower and other wet cleaning devices, but also the entrained submicron-sized aerosol-like white smoke bodies are effectively removed. it can. Also nitric acid,
In addition to vapor-generated gases such as hydrochloric acid and sulfuric acid, it also produces fine particle aerosols, which works effectively against gas generated during boiling of perchloric acid, which is usually difficult to remove, and also cleans various aerosols. You can expect an effect. Furthermore, it has a high effect of removing dust that accompanies exhaust gas, and also has an effect of removing solid aerosols of submicron-sized silica, ammonium chloride, ammonium nitrate, etc. that were almost passed through by conventional wet cleaning machines. ing.

(3) Compared with the conventional wet cleaning machine as an exhaust cleaning device when there are many cases in which liquid aerosol or fixed aerosol is entrained in addition to various harmful gases such as semiconductor manufacturing, metal pickling and plating processes. It is excellent in terms of purification function and does not require the addition of a high-performance electrostatic precipitator, so it has great economic merit.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an exhaust gas purifying apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Exhaust gas inlet 2 ... Exhaust gas outlet 3 ... Spiral cylinder 4 ... Rotating impeller 5 ... Cleaning liquid nozzle 6 ... Small hole 7 ... Perforated disk

Claims (1)

[Scope of utility model registration request] 1. A centrifugal impeller provided in a spiral cylinder having a suction port and a discharge port for exhaust gas, wherein a cleaning liquid nozzle is arranged in front of the suction port, and the exhaust gas and the liquid sprayed from the cleaning liquid nozzle are provided. An exhaust gas purifying apparatus, characterized in that a perforated disk having a large number of small holes forcibly passing through and contacting is disposed.