JP4771148B2 - Mist removal device - Google Patents

Description

  The present invention relates to a mist removing apparatus that is attached to various apparatuses that use a chemical solution and removes chemical mist contained in exhaust gas from the apparatus.

As is well known, for example, in a production process in a liquid crystal factory, various chemical solutions are used in each apparatus. Since the mist of the chemical solution is mixed in the exhaust gas, the mist in the exhaust gas is removed when treating the exhaust gas. A process is also required.
Therefore, in a conventional general liquid crystal factory, for example, as shown in FIG. 5, a large-scale water scrubber 4 is installed in an exhaust gas treatment facility for exhausting exhaust gas G generated from each production device 1 through an exhaust fan 3 through a duct 2. In addition, the exhaust gas G is washed by the water scrubber 4 to absorb and collect the mist, and then the exhaust gas G is discharged into the atmosphere. It is normal to recycle after processing.

Further, for example, Patent Document 1 proposes that a chemical solution mist removal / recovery device equipped with a special mist removal filter is attached to each production device, and such a device is used to collect and remove mist for each production device. Has been.
JP 2003-305322 A

However, according to the conventional general exhaust gas treatment facility as shown in FIG. 5, since the exhaust gas containing various mist generated from each production apparatus 1 is all processed in a mixed state, the water treatment facility 5 The washing water treatment process in Japan must be complicated and large.
Moreover, since the total extension of the path of the duct 2 from each production apparatus 1 to the water scrubber 4 becomes long, mist may be reliquefied in the duct 2, and therefore, the liquid in the main part of the duct 2 is liquid. It is necessary to provide a drain pipe for removal or to make the entire duct 2 have a liquid-tight structure, which is one factor in increasing the cost of the entire exhaust gas treatment facility.

  In that respect, as shown in Patent Document 1, if a chemical solution mist removing and collecting device is installed for each production device and the mist generated there is processed independently for each production device, the above-described batch operation is performed. Although the problem in the case of processing can be reduced, the chemical mist removing and collecting apparatus shown in Patent Document 1 uses a very special and expensive mist removing filter made of stainless steel, and the mist collecting efficiency due to it is also high. It is not always sufficient, and has not been widely spread.

  In view of the above circumstances, the present invention provides an effective and appropriate mist removing apparatus capable of efficiently recovering and removing mist generated from a production apparatus in a liquid crystal factory, for example, and sufficiently reducing facility costs and operation costs. The purpose is to do.

  The present invention is a mist removing device attached to various devices using a chemical solution to remove chemical mist contained in exhaust gas from the device, and includes a filter for collecting the mist to be removed. And the filter is formed of a nonwoven fabric made of polyolefin fibers.

In particular, in the mist removing device of the present invention, the mist collected by the filter is placed on the surface of the filter by arranging the filter in a posture that is perpendicular to the flow direction of the exhaust gas and along the vertical plane. Alternatively, it can be re-liquefied inside and allowed to spontaneously drop along the filter , and the non-woven fabric as a filter for that purpose should have a fiber density along the horizontal direction relatively lower than the fiber density along the vertical direction. Thus, it is assumed that the re-liquefied chemical solution component has a dropping path that naturally drops along the vertical fibers without being inhibited by the horizontal fibers .

In addition, by spraying cleaning water on the surface of the filter, the mist collected by the filter and its gaseous substances are absorbed, and the chemical components re-liquefied or recrystallized from the mist are washed away with the cleaning water. A watering mechanism is provided .
Furthermore, as the watering mechanism , a watering pipe having a plurality of watering holes formed at predetermined intervals on the lower peripheral surface is used, and the watering pipe is horizontally arranged near the upper part of the filter facing the upstream side in the exhaust gas flow direction. To do.

According to the mist removing apparatus of the present invention, since a nonwoven fabric made of polyolefin fibers is used as a mist removing filter, sufficient removal efficiency can be obtained by such an inexpensive filter material, and the equipment cost and operation for mist removal are obtained. Costs can be reduced sufficiently.
In particular, since the filter was installed in a vertical position along the vertical surface, and the liquid component of the nonwoven fabric as the filter was configured to have directivity and re-liquefied, the chemical solution component was automatically dropped along the filter . It is possible to effectively prevent the chemical component from staying in the filter or scattering to the downstream side, and the removal efficiency can be sufficiently increased.
In addition, since it has a sprinkling mechanism for spraying cleaning water to the filter, it can absorb not only mist but also gaseous substances, and the re-liquefied or re-crystallized chemical components can be washed away with cleaning water. The removal efficiency with respect to the whole component can be further improved.
Furthermore, since a water spray pipe having water spray holes formed at predetermined intervals is used as the water spray mechanism, an excellent cleaning effect can be obtained with a very simple configuration.

  FIG. 1 is an overall schematic configuration diagram of an exhaust gas treatment facility equipped with a mist removing apparatus 10 according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of the mist removing apparatus 10 according to the present embodiment. FIG. 3B is a vertical sectional view (a view taken along the line bb in FIG. 3A), and FIG. 3 is a conceptual diagram schematically showing the direction of the fiber density of the nonwoven fabric as the filter 11 in the mist removing apparatus 10. 4 is a diagram showing the mist removing performance of the mist removing apparatus 10 of the present embodiment.

  The exhaust gas treatment facility shown in FIG. 1 is applied to a liquid crystal factory, and is used for treating mist contained in exhaust gas from each production apparatus 1 in a lump in the same manner as the conventional one shown in FIG. In addition to the large-scale water scrubber 4, the exhaust gas treatment facility of the present embodiment additionally has a dedicated mist removing device 10 in the vicinity of each production device 1 for production. The main purpose is to first pass the mist generated from the apparatus 1 through the mist removing apparatus 10 without diffusing it around, and to remove and recover most of the mist there.

As shown in FIG. 2, the mist removing apparatus 10 of the present embodiment partitions the inside of a casing 12 having an inlet and an outlet for the exhaust gas G to be processed to form a flow path for the exhaust gas G in a meandering state. A filter 11 for collecting mist in the exhaust gas G is installed.
The filter 11 in the present embodiment is disposed in a posture standing along a vertical plane so as to be orthogonal to the exhaust gas flow in the horizontal and lateral directions on both sides in the casing 12, and the exhaust gas is exhausted by the filter 11. When the collected mist is efficiently collected and the collected mist is reliquefied on the surface or inside of the filter 11, the re-liquefied chemical component does not stay on the surface or inside of the filter 11. It will naturally drop from top to bottom naturally.

The filter 11 in this embodiment is formed of a nonwoven fabric made of a polyolefin resin having excellent resistance to various chemicals used in a liquid crystal factory, and the fiber diameter of the polyolefin resin is, for example, 30 to 40 μm. It is preferable to set the degree.
For example, as shown in FIG. 3, the non-woven fabric as the filter 11 is mainly along the vertical direction so that the chemical component reliquefied from the collected mist easily drops along the filter. The fiber density directionality is such that the fiber density along the left-right direction is relatively lower than the fiber density along the up-down direction. Thereby, the dripping of the re-liquefied chemical liquid component is automatically and quickly dripped along the vertical fiber without being obstructed by the right and left fibers, so that the chemical liquid component stays in the filter 11. In addition, it is possible to prevent the droplets from passing through the filter 11 and being scattered downstream by the exhaust gas flow, and excellent removal efficiency can be obtained.
In other words, when using a nonwoven fabric in which the fiber density is completely uniform in each direction or a nonwoven fabric in which the density of the fibers in the left-right direction is higher than the density of the fibers in the up-down direction on the contrary, the fibers along the left-right direction The dropping of the chemical liquid component is not obstructed and a clear dropping path is not formed, and the chemical liquid component reliquefied on the surface or inside of the filter 11 naturally stays there, and eventually the exhaust gas flow causes a considerable decrease in the filter. Since it will pass through 11 and will be scattered downstream, sufficient removal efficiency cannot be expected.

  Moreover, the mist removing apparatus 10 of this embodiment is provided with the watering mechanism 13 for spraying the cleaning water W on the surface of the filter 11 installed in the standing posture as described above. The watering mechanism 13 in the present embodiment is formed by forming a plurality of small-diameter water holes (not shown) at predetermined intervals on the lower peripheral surface of a small-diameter water pipe made of a chemical-resistant material such as vinyl chloride or stainless steel. In addition, the cleaning water W supplied from the cleaning water supply pipe 15 via the flow meter 14 is sprinkled from the upper part on the upstream side of the filter 11 in the form of a water film over the entire surface.

In this way, by spraying the cleaning water W on the surface of the filter 11 by the water spray mechanism 13, the sprayed cleaning water W flows down along the surface of the filter 11 and is collected by the filter 11 at that time. Mist and gas components gasified from the mist are absorbed by the cleaning water, and chemical components re-liquefied and recrystallized on the surface and inside of the filter 11 are also washed away by the cleaning water, whereby the chemical components Excellent removal efficiency with respect to the whole can be obtained. In addition, since the cleaning water W is sprayed over the entire upstream surface of the filter 11, clogging of the filter 11 can be effectively prevented, so that an increase in pressure loss can be prevented and maintenance frequency can be reduced.
Of course, since the directionality of the fiber density is adjusted so that the re-liquefied chemical component can be easily dropped on the filter 11 as described above, the sprayed wash water W is also smoothly along the filter 11 in the same manner. The washing water W does not stay in the filter 11 and water droplets are not scattered downstream.

  The cleaning water W supplied to each mist removing device 10 is recovered from the bottom of the casing 12 by the cleaning water recovery pipe 16 and sent to a dedicated individual water treatment facility 17 (see FIG. 1), where the cleaning water W Water treatment for separating and removing the chemical component from the water is performed. Therefore, the water treatment process in each individual water treatment facility 17 may be performed only on a specific chemical solution generated from a single production apparatus 1, and the conventional exhaust gas from each production apparatus 1 is mixed and processed collectively. Compared with the water treatment facility 5, the water treatment process can be simplified and the treatment efficiency can be improved.

FIG. 4 shows experimental results for confirming the performance of the mist removing apparatus 10 of the present embodiment. Experiments 1 to 3 all have a filter size of 200 × 250 mm, a filter surface wind speed of 1.5 to 2.2 m / s, and a water spray amount of 0.5 L / min (liquid gas ratio of 0.1 to 0.147 L / m ³ ). This was done under conditions. As a result, an excellent removal rate of 90% or more was obtained in any case, and the entire chemical component including not only mist but also gaseous substances and reliquefied or recrystallized components can be effectively removed. Therefore, the chemical solution solute removal rate is higher than the mist weight removal rate, and favorable results are obtained from the viewpoint of air environment conservation.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. Of course, the specific configuration of the entire apparatus, for example, the form of the casing 12 and the exhaust gas flow path in the casing 12 are described. About the form, the position and number of stages of the filter 11, the fiber diameter and fiber density of the polyolefin fiber in the nonwoven fabric as the filter 11, the configuration of the watering mechanism 13, etc., the type of mist to be removed, the required removal efficiency, and the processing should be performed Needless to say , an optimum design may be made within a range not departing from the gist of the present invention in accordance with the amount of exhaust gas and other various conditions.

In addition, in the exhaust gas treatment facility shown in FIG. 1, in addition to removing and collecting mist by the mist removal device 10 attached to each production device 1 and the corresponding individual water treatment facility 17, all the same as in the past A water scrubber 4 for exhaust gas and a water treatment facility 5 therefor are provided, so that sufficient treatment efficiency and reliability can be obtained as a whole factory. Of course, it is possible to obtain sufficient treatment efficiency and sufficient reliability only by attaching to each production apparatus 1, and in that case, it is impossible to omit the water scrubber 4 and the water treatment facility 5 therefor. is not.
Needless to say, the mist removing apparatus of the present invention is not limited to a liquid crystal factory and can be widely applied to various production apparatuses using various chemicals.

It is a figure which shows the outline | summary of the waste gas processing equipment provided with the mist removal apparatus which is embodiment of this invention. It is a figure which shows schematic structure of the mist removal apparatus which is embodiment of this invention, Comprising: (a) is a plane sectional view, (b) is an elevational sectional view. It is a figure which shows typically the directionality of the fiber in the nonwoven fabric as a filter. It is a figure which shows a mist removal performance similarly. It is a figure which shows the outline | summary of the conventional general waste gas treatment equipment.

Explanation of symbols

G exhaust gas W cleaning water 1 production device 2 duct 3 exhaust fan 4 water scrubber 5 water treatment facility 10 mist removal device 11 filter (nonwoven fabric made of polyolefin fiber)
12 Casing 13 Watering mechanism (watering pipe)
14 Flowmeter 15 Washing water supply pipe 16 Washing water recovery pipe 17 Individual water treatment facility

Claims (1)

A mist removing apparatus for removing chemical mist included in exhaust gas from the apparatus attached to various apparatuses using the chemical liquid,
Having a filter for collecting the mist to be removed, the filter is formed of a nonwoven fabric made of polyolefin fibers ,
By arranging in a posture of said filter erected along the orthogonal and vertical plane relative to the flowing direction of the exhaust gas, in the filter mist collected is re-liquefied on the surface or in the inside of the filter by the filter Along with natural dripping,
And the nonwoven fabric as a filter is that the density of the fibers along the left-right direction is relatively lower than the density of the fibers along the up-down direction, so that the re-liquefied chemical solution component is inhibited by the fibers in the left-right direction. Without having a dripping path that drops naturally along the vertical fiber ,
By spraying the washing water onto the surface of the filter, watering to wash with absorbing mist and the gas matter capturing, reliquefaction or recrystallized chemical components from the mist by the wash water by the filter Equipped with a mechanism ,
The watering mechanism comprises a watering pipe having a plurality of watering holes formed at predetermined intervals on the lower peripheral surface, and the watering pipe is horizontally disposed near the upper part of the filter facing the upstream side in the exhaust gas flow direction. A mist removing device characterized by comprising:

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