JP3945246B2 - Organic silicon removal equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an organic silicon removing apparatus for removing organic silicon contained in a gas such as factory exhaust gas.
[0002]
[Prior art]
Conventionally, various types of organic silicon have been used in various manufacturing processes, such as mold release agents used in product molding and product polishes, in many manufacturing processes or in products themselves. Yes. Organosilicon has properties suitable for various applications and is not toxic, so that the amount of its use tends to increase year by year.
[0003]
On the other hand, in order to regulate the generation of bad odor due to factory exhaust, deodorization of exhaust gas is often required. The most commonly used deodorization apparatus for deodorizing factory exhaust gas is a thermal catalyst system that uses a thermal catalyst for the treatment. In this apparatus, an odorous substance contained in exhaust gas is treated by oxidative decomposition under a thermal catalyst, and then the gas is discharged to the outside.
[0004]
By the way, if organic silicon is contained in the exhaust gas of a factory, when it is attempted to treat this with the above-mentioned thermal catalyst type deodorizer, a poisoning phenomenon of the catalyst occurs, which causes the running cost of the deodorizer. There is a problem that becomes high. As a specific example, silicon oil is most often used by polymerizing siloxane [(CH ₃ ) ₂ SiO] _n . When this is vaporized and adheres to the catalyst surface of the deodorizer, Oxidation reaction takes place on the surface, resulting in solid silicon dioxide (silica) particles, which clog the pores of the catalyst. As described above, when organic silicon is oxidized and decomposed in the deodorizing device to produce silica (SiO ₂ ) fine particles, the finely divided silica adheres to the catalyst and the catalyst deteriorates, so that the catalyst needs to be replaced. , Running costs will be high.
[0005]
Therefore, when treating exhaust gas with a catalyst, it is desirable to first treat the exhaust gas after sufficiently reducing the concentration of organic silicon in the exhaust gas.
[0006]
[Problems to be solved by the invention]
In this type of treatment, apart from the thermal catalyst, a relatively inexpensive pretreatment catalyst such as alumina is used. That is, in the above treatment, since an expensive platinum catalyst is usually used as the thermal catalyst, silicon is attached to this using a pretreatment catalyst that is less expensive than the platinum catalyst. By periodically replacing the catalyst for use, the life of the platinum catalyst is lengthened to suppress the cost increase. However, even when this method is employed, silicon that has passed through the pretreatment catalyst adheres to the platinum catalyst. For this reason, although the interval of exchange of the platinum catalyst is somewhat longer, the exchange of the catalyst is necessary and cannot be a sufficient cost measure.
[0007]
It is also conceivable that an adsorbent such as activated carbon is provided in front of the platinum catalyst and the exhaust gas is treated with the catalyst after adsorbing the organic silicon with the adsorbent. However, in this case, an odor substance is also adsorbed together with the organic silicon in the adsorbent (the organic silicon cannot be selectively treated), so that it is necessary to frequently exchange the adsorbent, and there is a problem of poor practicality.
[0008]
As described above, conventionally, when organic silicon in a gas is removed in advance by a deodorizing apparatus or the like, the cost may increase or the organic silicon may not be sufficiently removed. The present invention was devised in view of such problems, and an object of the present invention is to provide an organic silicon removing apparatus capable of sufficiently removing organic silicon contained in a gas such as factory exhaust gas. In addition, the cost increase associated with the processing is suppressed.
[0009]
[Means for Solving the Problems]
In the present invention, organic silicon contained in a gas such as factory exhaust gas is removed by making organic silicon into silica particles by low-temperature plasma and capturing it with a filter.
[0010]
Specifically, the present invention is premised on an organic silicon removing apparatus for removing organic silicon in a gas. And this organic silicon removal device is configured to generate a plasma so as to capture the silicon dioxide particles generated from the organic silicon by the low temperature plasma and the plasma generating part (11) that generates the low temperature plasma by the discharge in the gas flow path. And a filter (12) disposed downstream of the section (11) .
[0011]
In this configuration , organic silicon in the gas is oxidatively decomposed by the action of low-temperature plasma generated by discharge, and fine silicon dioxide (silica) particles are generated. The silica particles flow downstream with the gas and are captured by the filter (12). Therefore, the organic silicon in the gas is removed.
[0012]
In the present invention, the plasma generator (11) is configured to generate low-temperature plasma by streamer discharge .
[0013]
In this configuration , streamer discharge adopted as a discharge method for generating low-temperature plasma is generally generated in a columnar space between the discharge electrode (13) and the counter electrode (14). In this streamer discharge, if a region where low-temperature plasma is generated is enlarged and a gas is allowed to flow therethrough, only a part of the gas contacts the surface of the electrode (13, 14). It becomes difficult to adhere. In the streamer discharge, a wide plasma generation region can be obtained by enlarging the discharge region, so that the processing capability can be relatively easily increased.
[0014]
Further, in the present invention, the plasma generator (11) wipes the discharge electrode (13) having a plurality of discharge ends (13b) formed in a needle shape and the silicon dioxide film adhering to the discharge ends (13b). Wiping means (30) .
[0015]
In the present invention, the wiping means (30) is constituted by a sponge roller (31) that rolls with respect to the discharge end (13b) of the discharge electrode (13) .
[0016]
In the above configuration, when the streamer discharge is performed by the discharge electrode (13) having the needle-like discharge end (13b) , when the silica film adheres to the discharge electrode (13) , the silica film is removed from the sponge roller (31 ) it can be easily removed by comprising wiping means (30) from.
[0017]
【The invention's effect】
According to the present invention , organic silicon is made into particles by low-temperature plasma, and the particles are captured by the filter (12), so that the organic silicon in the gas can be reliably removed. Further, the siliconized particles are fine particles of 0.1 μm or less. On the other hand, if a HEPA filter or ULPA filter is used as a filter for collecting dust, high performance (dust collection rate of 99.9% or more) can be surely obtained, but the particles are easily charged in the discharge field. In consideration of the fact that the diffusion coefficient increases and the dust collection performance improves as the particles become smaller, it is practical to use inexpensive medium performance filters (dust collection rate of about 85% for 2 μm particles) and electret filters. Performance that does not cause problems can be obtained. For this reason, running cost can also be suppressed sufficiently.
[0018]
Further, according to the present invention , since streamer discharge is adopted as a discharge method of the plasma generation section (11), a relatively wide discharge region can be easily obtained, so that silica adheres to the electrodes (13, 14). And stable discharge is possible. Further, by widening the discharge region in this way, the organic silicon is granulated in a wide range, so that the processing capability can be enhanced.
[0019]
Further, according to the present invention, since the silica film adhering to the discharge electrode (13) of the streamer discharge can be easily removed by the wiping means (30) comprising the sponge roller (31) , the discharge state can be stabilized. Therefore, it is possible to reliably prevent the processing performance from deteriorating.
[0020]
[Premise Technology]
Hereinafter, the prerequisite technology of the embodiment of the present invention will be described in detail based on the drawings.
[0021]
This base technology is such that the organic silicon removal device (10) according to the present invention is used for pretreatment of deodorization in a thermal catalytic deodorization device (1) used for treating exhaust gas in various factories. This is an example.
[0022]
FIG. 1 is a schematic configuration diagram of a deodorizing apparatus (1) according to this prerequisite technology . As shown in the figure, this deodorizing device (1) is provided in the exhaust duct (2) of the factory. In this deodorization device (1), an organic silicon remover (organic silicon removal device) for removing organic silicon contained in the exhaust gas in order from the upstream side in the exhaust gas path partitioned by the exhaust duct (2). (Equipment) (10) and a deodorization treatment section (20) for decomposing and treating odorous substances in the exhaust gas from which the organic silicon has been removed under a catalyst.
[0023]
FIG. 2 is a schematic diagram showing the configuration of the organic silicon remover (10). This organic silicon remover (10) is a plasma generator (11) that generates low-temperature plasma by discharge in the gas flow path, and generates plasma to capture silica particles generated from organic silicon by low-temperature plasma. And a filter (12) disposed downstream of the section (11).
[0024]
The plasma generator (11) is configured to generate low-temperature plasma by streamer discharge. The plasma generator (11) includes a discharge electrode (13) and a counter electrode (14), and a power source (15) for applying a discharge voltage to both electrodes, in order to cause a streamer discharge. The discharge electrode (13) has a configuration in which a plurality of needle-like discharge ends (13b) are arranged vertically and horizontally on a substrate (13a), and the counter electrode (14) has a predetermined distance from the discharge electrode (13) ( For example, it is comprised by the flat electrode (14) arrange | positioned at intervals of 10-20 mm. The power source (15) is configured to apply a DC high voltage or a pulsed high voltage to both electrodes (13, 14). Then, streamer discharge is generated between both electrodes (13, 14) by the above configuration, and the exhaust gas of the factory is caused to flow into the discharge field, so that the organic silicon contained in the exhaust gas is made into particles. It is configured.
[0025]
As the filter (12), for example, a high efficiency particulate air filter (HEPA) filter or an ultra low penetration air filter (ULPA) filter is used. By using these filters, it is possible to collect fine particles of about 0.1 μm with a high efficiency of 99.9% or more.
[0026]
The deodorizing section (20) includes a catalyst structure (21) and a heater (22). Although the details are not shown in the catalyst structure (21), for example, a catalyst layer is formed on the surface of a honeycomb-shaped substrate on which a large number of small holes through which a gas passes is formed, or a fine catalyst What filled particles in the air permeable container etc. can be used. The catalyst structure (21) includes a thermal catalyst that is activated by heating and promotes the treatment of odor components in the exhaust gas. The heater (22) is arranged as a heating means in the vicinity of the catalyst structure (21) in order to heat the thermal catalyst and the exhaust gas to a high temperature to increase the activity of the catalyst.
[0027]
-Driving action-
Next, the operation of the deodorizing device (1) will be described.
[0028]
In this deodorizing apparatus (1), in the organic silicon remover (10), organic silicon in the gas is oxidized and decomposed by the action of low-temperature plasma generated by discharge, and fine silica particles are generated. Specifically, as shown in FIG. 3, organic silicon gas molecules are first subjected to plasma action to become particles of the order of 1 nm. These particles are aggregated by van der Waals force when the particles collide with each other and grow to particles of the order of 10 nm. Further, when the particles further collide with each other, the aggregation is repeated and particles of the order of 100 nm (0.1 μm) are formed. In the figure, particles of the order of 100 nm are shown only on the counter electrode (14) side, but particles of each particle size are dispersed between the electrodes (13, 14).
[0029]
The graph of FIG. 4 shows the state of particle concentration change accompanying the generation and aggregation of particles by low-temperature plasma in gas. When low-temperature plasma is generated in a gas flow containing organic silicon, the total particle concentration (here, particle size is not considered) increases rapidly until a certain period of time, and then the total particle concentration Will decline slowly. The total particle concentration is decreased because a large number of small-sized particles are aggregated to produce relatively large-sized particles of about 0.1 μm. As the total particle concentration decreases, the concentration of large particles on the order of 0.1 μm gradually increases, and this concentration gradually decreases so as to converge to the total particle concentration.
[0030]
The graph of FIG. 5 shows the results of measuring the concentration of only large-diameter particles of 0.1 μm or more. As shown in the figure, when about 5 minutes have elapsed since the power source (15) of the plasma generating section (11) is turned on, the concentration of particles starts to increase, and the concentration tends to increase until about 20 minutes. After that, the concentration of the particles is almost in an equilibrium state.
[0031]
In the organic silicon remover (10), the silica particles formed by the mechanism as described above flow to the downstream side of the plasma generation unit (11) in a state of being included in the exhaust gas, and the filter (12) Captured by Thus, since organic silicon is collected as particles, organic silicon in the gas is surely removed.
[0032]
In the organic silicon remover (10) of this base technology , when a discharge voltage is applied to both electrodes (13, 14), for each discharge end (13b), a columnar shape between the discharge electrode (13) and the counter electrode (14) Streamer discharge occurs in space. This streamer discharge is formed as a plasma column accompanied by light emission by continuous micro arc from the tip of the discharge end (13b) to the counter electrode (14), and the plasma column is formed in each discharge end (13b). Formed about.
[0033]
For this reason, in this base technology , the discharge region can be enlarged relatively easily, and by doing so, it is possible to enlarge the generation region of the low temperature plasma and increase the processing capability. Further, if the region where the low temperature plasma is generated is enlarged and a gas is allowed to flow therethrough, most of the gas does not come into contact with the discharge electrode (13), so that silica hardly adheres to the electrode.
[0034]
As described above, in this base technology , organic silicon can be effectively removed on the upstream side of the catalyst structure (21), so that the poisoning phenomenon in the catalyst can be prevented. Accordingly, since the replacement of the catalyst structure (21) is not required or the interval between the replacements can be increased, it is possible to prevent a decrease in performance while suppressing an increase in the running cost of the device (1).
[0035]
−Effects of prerequisite technologies−
According to this base technology , since organic silicon is made into particles by low-temperature plasma and captured by the filter (12), the organic silicon in the gas can be reliably removed. Further, since the siliconized particles are fine particles of the order of 0.1 μm and a HEPA filter or ULPA filter is used as the dust collecting filter (12), high performance can be obtained.
[0036]
Considering that the particles are charged in the discharge field and that the diffusion coefficient increases and the dust collection performance is improved when the particles become small, the medium performance (a dust collection rate of about 85% for 2 μm particles). ) Or a electret filter can be used to obtain performance that does not cause any practical problems. In addition, the running cost can be sufficiently suppressed by doing so.
[0037]
Furthermore, in this base technology , by adopting streamer discharge as the discharge method of the plasma generator (11), it is possible to widen the discharge region and make it difficult for silica to adhere to the electrode (13), so that stable discharge is achieved. Is possible. In addition, since the discharge region is widened, the organic silicon is granulated in a wide range, so that the processing capability can be enhanced.
[0038]
DETAILED DESCRIPTION OF THE INVENTION
In the above-mentioned base technology , silica hardly adheres to the tip of the discharge end (13b). However, it is conceivable that silica particles adhere to the discharge end (13b) in the form of a film after a predetermined operation time, for example. Accordingly, embodiments of the present invention is an organic silicon remover (10) of the base technology, and needle-like discharge end of the wiping means for wiping a silica film deposited on (13b) (30) is provided.
[0039]
As shown in FIGS. 6 to 8, the wiping means (30) rolls the sponge roller (31) against the discharge end (13b) of the discharge electrode (13), thereby causing the discharge electrode (13) to move. The tip silica film is configured to be removed. The organic silicon remover (10) of this embodiment is the above-mentioned premise technique in that the discharge direction of the streamer discharge is parallel to the gas flow direction except that the wiping means (30) is provided. Is different. For this reason, although not shown in detail, the discharge electrode (13) and the counter electrode (14) are constituted by mesh-like electrode plates so that exhaust gas passes therethrough.
[0040]
In this embodiment , the other parts are configured substantially in the same manner as the base technology . Therefore, in this embodiment , the wiping means (30) will be mainly described. Moreover, in FIG. 6, illustration of the deodorizing process part (20) is abbreviate | omitted.
[0041]
In this organic silicon remover (10), the drive shaft (32) and the driven shaft (33) are arranged in parallel to each other below and above the gas flow path. The drive shaft (32) and the driven shaft (33) are disposed at a position where a part of the flow path is widened. A drive pulley (34) is attached to both ends of the drive shaft (32), and a driven pulley (35) is attached to both ends of the driven shaft (33). Each driven pulley (35) is positioned vertically below the drive pulley (34) and is paired vertically. The drive belt (36) is hung on the upper and lower pulleys. Further, a motor (37) is connected to the drive shaft (32), and the driven shaft (33) is rotated together with the drive shaft (32) by starting the motor (37).
[0042]
As shown in FIG. 8, the sponge roller (31) comprises a shaft (31a) and a roller body (31b), and the shaft (31a) is connected to the drive belt (36) at the connecting portions at both ends thereof. . The roller body (31b) includes an inner diameter side sleeve (31c) and an outer diameter side sponge brush (31d), and the sleeve (31c) rotates with respect to the shaft (31a) so that the roller body (31b) The whole of rotates. The shaft (31a) is provided with stoppers (31e) positioned on both sides of the sleeve (31c) so that the sleeve (31c) does not move in the axial direction. When the motor (37) is activated, the sponge roller (31) moves up and down while the needle-like electrode end (13b) is stuck in or removed from the sponge brush (31d).
[0043]
During the operation of the deodorizing apparatus (1) in which the organic silicon remover (10) is activated, the sponge roller (31) is in a position retracted from the gas flow path as indicated by a virtual line in FIG. It has stopped. Then, when a predetermined time has elapsed since the start of the device (1) or when it is detected that a predetermined amount of silica has adhered to the tip of the discharge electrode (13), the motor (37) is started and the sponge roller (31) is turned on. Roll to the discharge end (13b) of the discharge electrode (13). By doing so, the movement of the tip of the discharge electrode (13) piercing or unplugging from the sponge brush (31d) is performed, and the silica film adhering to the discharge electrode (13) is removed.
[0044]
When the dirt on the discharge electrode (13) due to the silica particles is thus removed, the discharge state is stabilized. Therefore, it is possible to prevent the performance from being deteriorated when the operation of the apparatus (1) is resumed, and to continue removing organic silicon in the exhaust gas .
[0045]
Other Embodiments of the Invention
The present invention may be configured as follows with respect to the base technology and the embodiment described above.
[0046]
For example, in the base technology and the embodiment described above, as an example in which the organic silicon remover (10) is applied to the factory deodorization apparatus (1), the case of removing organic silicon contained in the exhaust gas of the factory has been described. The apparatus (10) of the invention may be applied to remove organic silicon in a copying machine or the like. In addition, the present invention can be effectively applied to a place where a spray containing organic silicon is used, such as a beauty salon.
[0047]
Further, as the high voltage power source (15) for causing discharge, any of a DC power source (15) , an AC power source (15) , or a pulse power source (15) may be used.
[0048]
Further, in the base technology , in the deodorizing apparatus (1), a thermal catalyst activated by heating is used, but in addition to this, a plasma catalyst activated by plasma, a photocatalyst activated by light, etc. Other catalysts may be used.
[0049]
In addition, a material used for the catalyst may be appropriately selected. For example, a base metal catalyst such as a Mn catalyst, a Ni catalyst, a V catalyst, a Mo catalyst, a W catalyst, a TiO ₂ catalyst, a BaTiO ₃ catalyst, Alternatively, various catalysts such as a three-way catalyst, a Pt catalyst, a Pd catalyst, and a noble metal catalyst such as an Rh catalyst can be used.
[0050]
FIG. 9 shows an example using a plasma catalyst. In this example, a discharge electrode (23) and a counter electrode (24) are arranged on both sides of a catalyst structure (21) containing a plasma catalyst, and low-temperature plasma generated between both electrodes is used as a plasma catalyst. It is supposed to work. For the discharge electrode (23) and the counter electrode (24), mesh-like electrode plates are used so that exhaust gas can pass therethrough.
[0051]
Moreover, as a plasma catalyst, the thing containing the mixture or complex oxide of manganese oxide and at least 1 sort (s) of iron, cerium, europium, lanthanum, and copper can be used, for example. By doing so, the odorous substance is decomposed very efficiently by the interaction between the catalyst composition and various active species generated by the low-temperature plasma, so that the decomposition performance can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a deodorizing apparatus according to a prerequisite technology of the present invention.
FIG. 2 is a schematic configuration diagram showing an organic silicon remover of the deodorizing apparatus of FIG.
FIG. 3 is a schematic diagram showing the mechanism by which organic silicon becomes silica particles.
FIG. 4 is a graph showing the state of particle concentration change accompanying the generation and aggregation of particles by low-temperature plasma in gas.
FIG. 5 is a graph showing the result of measuring the concentration of only particles having a size of 0.1 μm or more in FIG. 4;
FIG. 6 is a side view showing an organic silicon removing unit of the deodorizing apparatus according to the embodiment of the present invention.
7 is a perspective view showing a wiping means provided in the organic silicon removing unit of FIG. 6. FIG.
8 is a cross-sectional view of a sponge roller used in the wiping means of FIG.
FIG. 9 is a schematic configuration diagram showing a modified example of the deodorizing apparatus.
[Explanation of symbols]
(1) Deodorizer
(10) Organic silicon remover (Organic silicon removal equipment)
(11) Plasma generator
(12) Filter
(13) Discharge electrode
(13b) Discharge end
(14) Counter electrode
(20) Deodorizing section
(21) Catalyst structure
(22) Heater
(30) Wiping means
(31) Sponge roller

Claims (1)

An organic silicon removal apparatus for removing organic silicon in a gas,
Placed on the downstream side of the plasma generator (11) to capture the silicon dioxide particles generated from the organic silicon by the low temperature plasma and the plasma generator (11) that generates the low temperature plasma by discharge in the gas flow path has been a filter (12), provided with,
The plasma generator (11) is configured to generate low-temperature plasma by streamer discharge,
The plasma generator (11) includes a discharge electrode having a plurality of discharge end formed in a needle shape with (13b) (13), the wiping means for wiping the silicon dioxide film that adheres to the discharge end (13b) and (30) With
The wiping means (30) is composed of a sponge roller (31) that rolls with respect to the discharge end (13b ) of the discharge electrode (13) .

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