JP5326187B2 - Gas processing apparatus provided with gas pretreatment apparatus and cleaning method - Google Patents

Description

  The present invention relates to a gas pretreatment apparatus for gas treatment. More specifically, the present invention relates to a gas pretreatment device that performs pretreatment of a gas to be treated containing a sulfur-containing atomic compound and removes the contained sulfur atom compound, and a cleaning method for the gas pretreatment device.

Biogas, fuel gas such as coke oven gas, and the like contain a large amount of sulfur-containing atomic compounds (compounds containing sulfur atoms), but many sulfur-containing atomic compounds have toxicity and a strong odor. Examples of such sulfur-containing atomic compounds include hydrogen sulfide (H ₂ S), methyl mercaptan (CH ₃ SH), methyl sulfide ((CH ₃ ) ₂ S), methyl disulfide ((CH ₃ ) ₂ S ₂ ), and the like. Can be mentioned. The crude gas containing the sulfur-containing atomic compound is a cause of environmental problems such as corrosion of factory equipment, catalyst poisons in chemical plants, air pollution and water pollution due to its toxicity and strong odor. It has become.

Therefore, as a method for treating such a substance, there is a method based on biodegradation utilizing the action of microorganisms decomposing harmful substances (see Patent Document 1). For example, the biological reaction of Formula (3) proceeds by adding bacteria of the genus Thiobacillus as a microorganism to hydrogen sulfide (H ₂ S), which is the sulfur-containing atomic compound. The reaction of the formula (3) is a reaction that proceeds by a two-stage reaction of the formula (1) and the formula (2). When processing a normal low-concentration hydrogen sulfide, the formula (1) and the formula (2) are used. ) Proceeds at the same rate, and eventually hydrogen sulfide becomes water-soluble sulfuric acid (H ₂ SO ₄ ), so it can be dissolved in the washing solution as it is and removed from the reaction system. And the biological deodorization apparatus which packed the said microorganisms into the packed bed based on such reaction is utilized. In addition, the pH range which becomes the biological activity differs with the said microorganisms, It is important for the water used in a biological deodorizing apparatus to maintain the pH range.

On the other hand, when biological treatment of high-concentration hydrogen sulfide is performed by microorganisms, the reaction of formula (1) proceeds excessively compared to the reaction of formula (2), so that solid sulfur (S) is converted into a biological treatment tower. A large amount is deposited in the packed bed. And since sulfur is insoluble in water, it remains in the filler in the biological deodorization apparatus and causes clogging. Such a problem similarly occurs when other sulfur-containing atomic compounds such as mercaptans and methyl sulfide are biologically treated. On the other hand, FIG. 3 of Patent Document 1 discloses a deodorizing device in which a microorganism is supported on a carrier having elasticity using a biological reaction. By using a microbial carrier having elasticity, the above problem is solved by washing off sulfur adhering to the carrier or dust in the gas to be treated from the inside of the filler by washing with water.
Japanese Patent Application Laid-Open No. 2003-311121.

  However, even the biological deodorization apparatus has problems in the following points. The precipitated sulfur molecules are water-insoluble, and a large amount of washing solution is required to wash out all of them, and the microorganism carrier is washed away from the carrier because a large amount of washing solution is used to wash the microorganism carrier. Since the water in the apparatus is diluted with this cleaning solution and the acidity becomes uniform, the ability to decompose and deodorize microorganisms decreases due to the decrease in activity depending on the type of the microorganisms.

  Therefore, the present invention provides a gas pretreatment device that performs pretreatment such as the biological deodorization device that can solve these technical problems, particularly a gas pretreatment device that treats a sulfur-containing atomic compound contained in a gas to be treated. The main purpose is to provide.

The present invention relates to a gas pretreatment device that removes a sulfur-containing atomic compound from a gas to be treated containing a sulfur-containing atomic compound, and a living body used as a gas main treatment that subsequently removes the sulfur-containing atomic compound from the gas to be treated. An apparatus that connects processing towers,
It has a processing tower for circulating the gas to be processed, and inside the processing tower,
A microbial carrier for contacting the gas to be treated in an upward flow;
A watering part for watering the microorganism carrier from above;
Immersion means for immersing the microbial carrier with a cleaning liquid;
A blowing section for blowing air from below to the microbial carrier,
The sprinkling liquid sprayed from above on the microorganism carrier is to use again the sprinkling liquid used for sprinkling ;
When the microbial carrier is blown from below by the blowing unit, the microbial carrier in the packed bed is gas-liquid washed while the level of the washing liquid in the treatment tower is raised and lowered by the immersion means and displaced. There is provided a gas treatment device comprising the gas pretreatment device characterized by the above.

By the pretreatment apparatus provided for the present invention, at least the concentration of the sulfur-containing atomic compound contained in the gas to be treated is pretreated to a certain concentration or less, thereby preventing a reduction in processing capacity in the subsequent main treatment tower. Gas treatment can be performed efficiently. Further, by circulating the water spray in the gas pretreatment device as a circulating water spray, it contributes to water saving and can improve the efficiency of attaching microorganisms to the carrier.

  Moreover, in this invention, the gas processing apparatus which carries the said microorganisms carrier on the filler with a particle size of 5-40 mm can be provided. As a result, the pressure loss of the filler when the gas to be treated is vented can be reduced and the handling can be facilitated.

  Furthermore, in the present invention, a gas processing apparatus is provided in which the flow rate of the gas to be processed is vented at LV (Linear Velocity) = 500 to 3000 m / hr and SV (Space Velocity) = 1000 to 3000 / hr. it can. Thereby, a to-be-processed gas can be made to contact a microorganisms carrier more effectively, and biological treatment can be carried out more efficiently.

In the pretreatment device provided in the present invention, when air is blown to the microbial carrier by the blower, when the blower is blown from below to the microbial carrier, the surface of the cleaning liquid in the treatment tower is immersed by the dipping means. while displacing raises lowering the water level, the microbial support of the packed bed as possible out to the gas-liquid cleaning. Thereby, the liquid level of the cleaning liquid fluctuates while bubbles burst at the liquid level of the cleaning liquid, so that the cleaning effect can be exhibited evenly over the entire microbial carrier in contact therewith.

And in this invention, it has a processing tower which distribute | circulates the to-be-processed gas containing a sulfur-containing atomic compound,
A microbial carrier for bringing the gas to be treated into contact with the inside of the treatment tower in an upward flow;
A watering part for watering the microorganism carrier from above;
Immersion means for immersing the microbial carrier with a cleaning liquid;
A gas pretreatment device that removes the sulfur-containing atomic compound from the gas to be treated, and a fan that blows air from below to the microorganism carrier; and subsequently removes the sulfur-containing atomic compound from the gas to be treated. A cleaning method for a gas pretreatment device in an apparatus connected to a biological treatment tower used as a main gas treatment,
The sprinkling liquid sprayed from above on the microorganism carrier is to use again the sprinkling liquid used for sprinkling;
When the microbial carrier is blown from below by the blowing unit, the microbial carrier in the packed bed is gas-liquid washed while the level of the washing liquid in the treatment tower is raised and lowered by the immersion means and displaced. It is possible to provide a cleaning method for a gas pretreatment device.
By this cleaning method, clogging of the microbial carrier due to precipitated sulfur, dust and the like can be prevented and gas treatment can be performed efficiently.

  According to the gas treatment device of the present invention, when the gas to be treated containing the sulfur-containing atomic compound is treated with the microorganism carrier, the microorganisms are effectively removed by removing the precipitated sulfur and the dust in the gas to be treated. The target gas can be efficiently processed by preventing clogging of the carrier.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the accompanying drawings. Note that the embodiments shown in the drawings illustrate preferred embodiments of the present invention, and the present invention is not construed narrowly.

  FIG. 1 is a simplified diagram of a first embodiment of a gas pretreatment apparatus according to the present invention and an apparatus in which a normal biological treatment tower used as the main treatment is connected thereafter. For convenience of explanation, all drawings used below show a simplified configuration of the apparatus. The code | symbol 1 shown by FIG. 1 has shown the gas pre-processing apparatus for the high concentration hydrogen sulfide removal of circulation type watering. Reference numeral 1 ′ indicates a normal biological deodorization apparatus used as the main process.

  First, the main configuration of the apparatus according to the present embodiment will be described. The pretreatment tower 11 includes a packed bed 11a filled with a microbial carrier, a sprinkling portion 11b for spraying the packed bed 11a from above, and a water supply port for feeding a cleaning solution for immersing the packed bed 11a into the pretreatment tower 11. 11c and a cleaning air pipe 11d for blowing air from below to the packed bed 11a. The pretreatment tower 11 is connected with two tanks, a circulating water tank 121 and a water tank 122, and the sprinkling part 11b is pumped from the circulating water tank 121 by a watering pump 13 and sprays water from above the packed bed 11a. It is. Moreover, as the immersing means for the microorganism carrier, the water in the water tank 122 is supplied to the lower part of the pretreatment tower 11 from the water supply port 11c by the washing pump 14, and the packed bed 11a is immersed. Further, the cleaning air pipe 11d is configured to send air from the blower 15 and eject air from the lower side of the packed bed 11a to separate and clean sulfur, dust and the like attached to the packed bed 11a.

  Next, the flow of the gas to be treated (hereinafter referred to as “original odor”) containing high-concentration hydrogen sulfide will be described. The original odor is sent to the pretreatment tower 11 via the original odor duct 16 and pretreated, and then subjected to the main treatment by the subsequent biological deodorization apparatus 1 '. In the original odor duct 16, the original odor duct 16 is raised to a position higher than the water level at the time of immersion cleaning and then returned to the pretreatment tower 11 so that the washing water does not flow back and return during washing in the pretreatment tower 11. It is desirable to design it to flow in (see FIG. 1). Then, when the concentration of hydrogen sulfide in the original odor is low, the main treatment can be performed by sending the raw odor directly to the biological deodorization apparatus 1 ′ via the bypass duct 17. The bypass duct 17 is a duct that bypasses the pretreatment tower 11 and is not necessarily provided. However, by providing the bypass duct 17, the gas treatment can be continued in the biological deodorization apparatus 1 ′ via the bypass duct 17 even when the pretreatment tower 11 is being cleaned, and two or more pretreatment towers are used. When 11 is connected, it is possible to perform gas treatment in another main processing tower while washing in one main processing tower. In addition, in this invention, it does not limit to ventilating the inside of a pre-processing tower | column upwardly about the ventilation direction of an original odor, What is necessary is just to be able to ventilate so that the said microorganisms carrier may be contacted.

  The packed bed 11a in the pretreatment tower 11 is filled with a carrier to which microorganisms are accustomed and easy to grow and carry. The microorganism used in the present invention can be appropriately selected according to the sulfur-containing atomic compound to be treated. For example, when it is desired to treat hydrogen sulfide as in this embodiment, it grows mainly from bacteria of the genus Thiobacillus, and when treated with other sulfur-containing atomic compounds such as methyl mercaptan, the genus Hyphomicrobium or the genus Thiobacillus What is necessary is just to grow mainly in bacteria. In addition, although the suitable pH range which becomes biological activity differs according to these bacterial microorganisms, for example, in this embodiment, the bacteria of the said Thiobacillus genus are used, The suitable pH range is about 1.0-3.5. is there. In particular, since sulfuric acid, which is a strong acid, is produced in a biological reaction by microorganisms (see formula (3)), it is important to appropriately control so as to maintain a suitable pH range in a circulating water system or the like in the treatment apparatus according to the present invention. It is. The method for controlling the pH value is not particularly limited. For example, according to the pH value measured by the pH meter 18, the cleaning liquid is drained from the watering drain 19, or makeup water to the circulating water tank 121 is supplied from the water tank 122. For example, a method of replenishing and diluting continuously or intermittently, a method of controlling by appropriately adding an acidic or alkaline additive to the circulating water system, and the like can be mentioned.

  Further, the carrier for supporting the microorganism filled in the packed bed 11a is not particularly limited, but preferably a carrier having properties such as not floating when immersed in water and not being worn by air washing is desirable. The size of the carrier is not particularly limited, but preferably the particle size is 5 to 40 mm, more preferably 15 to 25 mm. This is because by setting the size of the carrier as described above, the pressure loss of the packed bed 11a when the original odor is passed can be reduced, and the handling becomes easy. An example of such a carrier is a porous carrier made of synthetic resin or ceramic.

  The immersing means for the microbial carrier is to supply the cleaning liquid from the water supply port 11c to the lower part inside the pretreatment tower 11 by the cleaning pump 14 connected to the water tank 122, and immerse it from below the packed bed 11a. However, the present invention is not limited to supplying the cleaning liquid from below as the dipping means. For example, a water spray used for water spraying from above can be used as a cleaning liquid.

The watering part 11b in the pretreatment tower 11 is used to wash away sulfuric acid (or sulfurous acid or thiosulfuric acid) generated by the biological reaction of the microorganism from the packed bed because the microorganisms in the packed bed 11a are not dried and killed. It is intended to sprinkle water. Further, the water sprayed from above the packed bed 11a flows to the lower part of the pretreatment tower 11, but is sent to the circulating water tank 121 by a solenoid valve or the like, or is directly sent to the water spray drain 19 to be discharged outside. You can also. Further, by providing the carrier trap 20 in the watering drain or the like, it is possible to collect the carrier and the like that have been peeled off from the packed bed 11a. And the sprinkling water sent to the circulating water tank 121 is again used for sprinkling by the sprinkling pump 13 in the sprinkling part 11b (circulating watering). In the case of using a microorganism whose biological activity is low in the low pH range as in this embodiment, sulfuric acid (H ₂ SO ₄ ) and the like produced by a biological reaction is circulated in the system by using the circulating water sprinkler. It is suitable for maintaining the value (see formula (3)), scale components such as calcium and iron contained in water supplied from outside the system are not easily deposited in the device, and the piping of the device is not easily clogged. There are advantages. However, in this invention, it is not limited to the circulation type watering like this embodiment, The transient watering which drains the water once used for watering as it is may be sufficient.

  The dipping means for supplying the cleaning liquid from the water supply port 11c in the pretreatment tower 11 and immersing the microbial carrier, and the blower unit 11d for blowing air to the microbial carrier include clogging substances such as sulfur and dust adhering to the packed bed 11a. Gas-liquid cleaning is performed by aerating the filling layer 11a immersed in the cleaning liquid from below to remove it. For example, cleaning water is supplied from the water supply port 11c into the pretreatment tower by the cleaning pump 13, and the packed bed 11a of the microorganism carrier is immersed therein. Subsequently, air is blown from the lower side of the apparatus to the microbial carrier by the blower 15 to aerate the microbial carrier to remove the clogging substance. The cleaning air may be introduced from below the pretreatment tower 11 so as to uniformly flow into the packed bed 11b to be cleaned, and the method is not particularly limited. For example, holes having a diameter of about 1 mm to 5 mm are formed. An opened cleaning air pipe, blower board, blower tube, and the like can be arranged in the entire lower portion of the pretreatment tower 11 (see FIG. 1). In the present invention, the means for blowing cleaning air is not limited to the blower, and for example, it can be blown by a compressor or the like.

  Furthermore, in the present invention, the gas-liquid cleaning procedure is not limited to starting the gas-liquid cleaning after the cleaning liquid in the pretreatment tower is full. Preferably, when blowing air to the microorganism carrier, it is more preferable to blow air while displacing the water level of the cleaning liquid in the processing tower. In the gas-liquid cleaning, the gas-liquid cleaning can increase the cleaning effect of the microorganism carrier by bursting air bubbles on the surface of the cleaning liquid, but the liquid level will rise if the cleaning liquid is being supplied or drained. Alternatively, since the air bubbles are descending, the bubbles burst in the packed bed evenly. For example, in the present embodiment, it is more preferable to perform air cleaning while supplying the cleaning liquid or once draining the water after the water is full. Although not shown, if the packed bed is given a function of moving up and down in the processing tower, gas-liquid cleaning can be performed while moving the packed bed up and down even when the water level of the cleaning liquid is constant.

  Further, when the circulating cleaning liquid contains a large amount of sulfur, dust, etc., it can be drained out of the system by the watering drain 19 and newly supplied from the water tank 122 to the circulating water tank 121. Or the water spray drain water at the time of a normal driving | operation can be stored, and this water spray drain water can also be reused for the water supply at the time of washing | cleaning. Thereby, it can prevent that the deodorizing microorganisms hold | maintained at the packed bed 11a in the pretreatment tower 11 at the time of washing | cleaning completely fall off, and are drained as it is. The water in the water tank 122 can be used both for cleaning in the pretreatment tower 11 and for supplying water to the circulating water tank 121. If necessary, the water tank for cleaning and the water tank for supplying water are used. You may install separately. In the present invention, the drainage from the processing tower to the outside is not particularly limited, but preferably a trough structure that can drain the stored contaminated water evenly is desirable.

  In the present invention, the frequency of the gas-liquid cleaning is not limited. For example, the gas treatment apparatus according to the present invention may be performed periodically, for example, once a week to once a year, although it varies depending on the scale, usage environment, and the like. Alternatively, the aeration pressure loss in the processing tower may be measured periodically, and gas-liquid cleaning may be performed when the pressure loss value reaches a certain value (for example, 1 kPa).

  In the gas pretreatment apparatus according to the present invention, it is possible to perform a pretreatment for reducing the high-concentration sulfur-containing atomic compound contained in the original odor to a certain concentration or less. Then, the sulfur-containing atomic compound remaining in the pretreated raw odor can be completely treated by the subsequent treatment apparatus (biological treatment tower 1 ′). The content concentration of the sulfur-containing atomic compound contained in the original odor is not particularly limited, but is preferably 50 ppm (volume ratio) or more, more preferably 100 ppm (volume ratio) or more, and 1000 ppm (volume ratio). It is desirable that If the concentration is 50 ppm (volume ratio) or less, the concentration can be treated only with a normal biological deodorization tower. If the concentration is 1000 ppm (volume ratio) or more, the pretreatment tower 11 according to the present invention can be enlarged, This is because it is necessary to connect other devices as processing.

  Further, in the present invention, the target of the original odor is not particularly limited, but is preferably a gas containing an odor component generated in a sewage treatment plant or human waste treatment plant such as hydrogen sulfide or methyl mercaptan. The TOC concentration (total organic carbon concentration) of the original odor generated in such a treatment plant is 50 ppm or less, more desirably 10 ppm or less. In such a concentration, the biological deodorization apparatus does not generate a sludge component due to the microorganisms taking in organic components as nutrients, and the sludge component adheres to the microbial carrier and the treatment device is blocked. Does not occur.

  And although this subsequent processing apparatus is not specifically limited, It is desirable that it is a biological deodorization tower. This is because the biological deodorization tower has a problem that a large amount of sulfur is deposited inside the biological treatment tower when an original odor containing a high concentration of sulfur-containing atomic compound is directly ventilated. Therefore, by using the gas pretreatment device according to the present invention as pretreatment of such a biological deodorization tower, clogging due to sulfur and dust is prevented, and the original odor is continuously treated and stabilized, and the failure of the treatment device is prevented. Can contribute.

  FIG. 2 is a simplified diagram of a second embodiment of a gas processing apparatus according to the present invention. The code | symbol 2 shown by FIG. 2 has shown the gas pre-processing apparatus for the high concentration hydrogen sulfide removal of a transient watering.

  First, the main configuration of the apparatus according to the present embodiment will be described. The pretreatment tower 21 includes a packed bed 21a filled with a microorganism carrier, a water spray pipe 21b for spraying water from above into the packed bed 21a, and a cleaning liquid pipe 21c for feeding a cleaning liquid for immersing the packed bed 21a into the pretreatment tower. And a cleaning air pipe 21d for blowing air from below to the packed bed 21a. The watering pipe 21b is pumped from the water tank 22 by a watering pump 23 and sprays water from above the packed bed 21a. The microbial carrier immersing means immerses the filling layer 21a by supplying cleaning water from the cleaning liquid pipe 21c to the water in the water tank 22 by the cleaning pump 24. Further, the blower 24 ejects air from the cleaning air pipe 21d to peel and clean the sulfur, dust and the like adhering to the packed bed 21a. Hereinafter, points different from the first embodiment according to the present invention will be described with emphasis.

  The watering part 21 b in the pretreatment tower 21 is a transient watering that uses the water in the water tank 22 as watering water and discharges it directly from the drainage drain 29 after watering. In addition, in this embodiment, although the water for the water tank 22 is used, you may provide the water storage water storage tank separately. Furthermore, in the present invention, there is no particular limitation on the makeup water supplied to the water tank 22. For example, secondary water from other wastewater treatment facilities, sand filtered water, industrial water and the like can be used as makeup water. However, as described above, there are cases where these waters contain a lot of scale components that cause clogging of piping. However, if an appropriate treatment such as addition of a scale inhibitor to the intermediate water or magnetic treatment to the piping in the apparatus is performed, the gas treatment apparatus according to the present invention can be used effectively.

In addition, when it is desired to treat methyl sulfide, methyl disulfide, or the like among sulfur-containing atomic compounds by the gas treatment apparatus of the present invention, the gas treatment apparatus for transient watering as in this embodiment is suitable. This is because many bacteria such as Thiobacillus that degrade sulfur-containing atomic compounds other than hydrogen sulfide and mercaptans, such as methyl sulfide and methyl disulfide, are active at pH values near neutral. That is, if water is sprayed on the bacteria by circulating water (see FIG. 1), acidic substances such as sulfuric acid (H ₂ SO ₄ ) produced by its own biological reaction also circulate in the system. Becomes too low (see equation (2), etc.). In addition, in the gas treatment apparatus 2 which concerns on this embodiment, it measures with the pH measuring meter 28 provided in the drainage drain 29, According to the value, the water supply from the water tank 22 or the neutralizing agent to the water for watering It can be maintained and controlled at a suitable pH value by administration and the like.

  FIG. 3 is a simplified diagram of a third embodiment of a gas processing apparatus according to the present invention. The code | symbol 3 shown by FIG. 3 has shown the gas treatment apparatus for the high concentration hydrogen sulfide removal of the temporary watering provided with the packed bed for pre-processing, and the packed bed for this processing in the processing tower. .

  First, a main configuration according to the present embodiment will be described. The treatment tower 31 includes a pretreatment packed bed 31a filled with a microorganism carrier, a main treatment packed bed 31a ′, a water spray pipe 31b for spraying the packed beds 31a and 31a ′ from above the treatment tower, and the pretreatment filling. A cleaning liquid pipe 31c for feeding a cleaning liquid for immersing the layer 31a into the processing tower and a cleaning air pipe 31d for blowing the pretreatment packed bed 31a from below are provided. And the gas processing apparatus which concerns on this embodiment performs the one-step process with the microorganisms carrier of the pre-processing packed bed 31a, and the integrated gas processing apparatus which performs a two-stage process with this processing packed bed 31a 'provided thereabove It is. Specifically, the concentration of the sulfur-containing atomic compound contained in the original odor is processed to a low concentration in the pretreatment packed bed 31a, and the remaining sulfur-containing atomic compound and the like are completely processed in the treated packed bed 31a ′. Is. Further, at least the pretreatment packed bed 31a can be cleaned by the cleaning liquid from the cleaning liquid pipe 31c and the blown air from the cleaning air pipe 31d. Hereinafter, points different from the first embodiment and the second embodiment according to the present invention will be described with emphasis.

  In the present invention, the number of packed beds is not limited to two. Although not shown, for example, a triple packed bed is provided in the processing tower, and the bottom and middle packed beds are filled with microorganisms that decompose hydrogen sulfide, and the upper packed bed is a microorganism that decomposes ammonia and the like. Can also be supported. Then, an original odor containing high-concentration hydrogen sulfide and a sulfur-containing atomic compound such as ammonia is passed through the treatment tower in an upward flow. As a result, the high-concentration hydrogen sulfide is pretreated in the bottom packed bed of the treatment tower, the low-concentration hydrogen sulfide is pretreated in the next packed bed, and ammonia and the like are treated in the next packed bed. It can be set as the processing tower which can also process a nitrogen-containing compound. That is, in the present invention, a gas processing apparatus having two or more packed beds filled with a microbial carrier to be brought into contact with the original odor can be provided inside the gas processing tower. By integrating such a packed bed, it can be used as a simple gas treatment device with reduced installation and maintenance costs, and the raw odor mixed with toxic gases other than sulfur-containing atomic compounds is treated in the same tower. You can also

  The water sprinkling part 31b is provided above the pretreatment filling layer 31a and the main treatment filling layer 31a ′, but the present invention is not limited to providing the watering parts at a plurality of locations. That is, it is also possible to provide a simple gas treatment device in which the water sprinkling part is provided only above the treatment packed bed 31a ′. This is because by spraying the main treatment packed bed 31a ′, it is inevitably possible to simultaneously spray the pretreatment packed bed 31a provided below the main processing packed bed 31a ′.

  Next, the flow of the original odor is shown. The original odor is sent to the lower part of the main processing tower 31 through the original odor duct 36 and pretreated in the pretreatment packed bed 31a, and then main processed in the main treatment packed bed 31a ′ and exhausted. Further, when hydrogen sulfide has a low concentration or the like, it is possible to perform only the main processing by directly sending it to the main processing packed bed 31a ′ via the bypass duct 371. Alternatively, the exhaust can be performed through the bypass duct 372 without even performing this process. Therefore, although not shown, a gas detector and analyzer can be installed at the entrance of the original odor duct, and automatic control linked to the open / close valve of each duct according to the analysis result such as the type and concentration of the original odor is possible. It is.

  Here, an experiment was conducted for the purpose of confirming the effect of the present invention. Specifically, regarding the gas treatment apparatus for removing high-concentration hydrogen sulfide according to the present invention, the ability to remove hydrogen sulfide, the effect of circulating water, the washing effect of the microorganism carrier, the sustainability of the treatment effect, the influence of the particle size of the carrier, LV An experiment was conducted for the purpose of verifying the influence of the SV and the influence of the SV.

  The method and conditions of Experiment 1 were as follows. A gas treatment apparatus in which a conventional biological deodorization apparatus (hereinafter referred to as “the present treatment apparatus”) is connected to a gas pretreatment apparatus for removing high-concentration hydrogen sulfide (hereinafter referred to as “pretreatment apparatus”) according to the present invention. It was used. And it experimented using the processing apparatus of RUN1 and RUN2 (refer Table 1). Specifically, as a pretreatment device according to the present invention, a circulating watering pretreatment device (RUN1, see FIG. 1) and a transient watering pretreatment device (RUN2, see FIG. 2) are used for comparison. investigated. In this experiment, a mixed gas containing high-concentration hydrogen sulfide was used as the original odor. The flow rate of the original odor was supplied to each pretreatment apparatus so that the hydrogen sulfide concentration was maintained at an average value of 120 ppm, a maximum value of 520 ppm, and a minimum value of 0 ppm.

  Further, pre-processing of RUN1 and RUN2 was performed under the conditions shown in Table 2, and this processing was performed under the conditions shown in Table 3.

<Hydrogen sulfide removal capability>

  In the pretreatment apparatus according to the present invention, the hydrogen sulfide removal capability was examined by the following evaluation procedure. The gas to be treated after the pretreatment in RUN1 and RUN2 was collected, the hydrogen sulfide concentration was measured, and the average value was obtained. In addition, the removal rate of hydrogen sulfide was evaluated by the numerical formula of Formula 1.

  As a result, the hydrogen sulfide concentration average value after pretreatment was 24 ppm (removal rate 80%) in RUN1, and the hydrogen sulfide concentration average value after pretreatment was 21 ppm (removal rate 83%) in RUN2. Therefore, it was shown that both RUN1 and RUN2 have high hydrogen sulfide removal ability by using the pretreatment apparatus according to the present invention.

  <Effect of circulating water>

  In the pretreatment apparatus according to the present invention, the effect of circulating water in the case of circulating watering was examined by the following evaluation procedure. In RUN1 and RUN2, the pressure loss values of the respective pretreatment devices on the 23rd and 29th days from the start of operation were measured, and the pressure loss increase values during this period were compared. In addition, RUN1 and RUN2 have different LVs of the gas to be processed, and therefore, pressure loss per sulfur addition during the period was obtained and compared. The results are shown in Table 4. As a result, it was confirmed that the increase in pressure loss from 23 to 29 days can be reduced to about 1/4 to 1/5 by the effect of circulating water in the present invention (Table 4; RUN1: 0.03 mmAq / m / m). g-S, RUN 2: 0.13 mmAq / m / g-S). In addition, when the inner wall surface of the pretreatment device was visually observed in RUN 1 using circulating water, it was also confirmed that the adhesion of sulfur to the inner wall surface was suppressed. Therefore, in the pretreatment apparatus according to the present invention, the circulation watering is used to increase the efficiency of biological adhesion to the carrier, to suppress the increase in the pressure loss of the packed bed, and to suppress the adhesion of sulfur to the wall of the deodorization tower. It was shown that

  <Cleaning effect of microbial carrier>

  About RUN1 which uses circulating water, the washing | cleaning effect of the microorganisms carrier at the time of removing the sulfur adhering to the packed bed of a pretreatment apparatus by gas-liquid washing was evaluated. First, after measuring the pressure loss when the carrier was new, the pressure loss after operating for one week was measured. The used packed bed was gas-liquid washed with washing water and washing air inside the processing tower, and the pressure loss after washing was measured. The results are shown in Table 5. From this result, it is shown that the pressure loss is recovered to about the time of the new carrier (Table 5; 120 mmAq / m) (Table 5; 90 mmAq / m), and the gas-liquid cleaning is sufficiently effective for the precipitated sulfur and the like. I was able to confirm.

  <Durability of treatment effect>

  The hydrogen sulfide concentration of the gas after the main treatment processed by each apparatus used for 6 months was measured by continuously using each for 6 months under the conditions of RUN1 and RUN2. As a result, even if RUN1 and RUN2 were used continuously for 6 months, the average hydrogen sulfide concentration after treatment was 0.1 ppm. From this result, by connecting the pretreatment apparatus according to the present invention to the microbial deodorization tower, there is no problem of clogging of the packed bed of the pretreatment apparatus or the present treatment apparatus, and a high removal effect (treatment effect) is continuously obtained. It was confirmed that it can be demonstrated.

  <Influence of carrier particle size>

  The other conditions were the same as in Table 2 except that the particle size of the carrier was changed using the circulating watering type pretreatment device shown in FIG. 1 (however, a new carrier was introduced after aeration for 2 weeks without washing). In order to confirm the removal performance of hydrogen sulfide, an experiment was conducted. The hydrogen sulfide used as the gas to be treated was artificially adjusted so that its concentration was kept constant at 130 ppm. Table 6 shows the results of the removal rate of hydrogen sulfide of each carrier particle size after aeration (microbe acclimatization) for 2 weeks.

  As shown in Table 6, the removal rate of hydrogen sulfide is 80% or more when the particle size of the support is 5 to 40 mm, and the removal performance of hydrogen sulfide is high when the support particle size is 5 to 40 mm. It has been shown. And it was shown that the removal performance tends to deteriorate at a particle size larger than this.

  <Influence of LV>

  Using the circulating watering type pretreatment device shown in FIG. 1, while changing the filling thickness of the carrier and changing LV so as to keep SV = 1500 / hr constant, other conditions are the same as in Table 2 An experiment was conducted to confirm the removal performance of hydrogen sulfide under the conditions (however, the washing was not performed and replaced with a new support after aeration for 2 weeks). The hydrogen sulfide used as the gas to be treated was artificially adjusted so that its concentration was kept constant at 130 ppm. Table 7 shows the results of the removal rate of hydrogen sulfide in each aeration LV of hydrogen sulfide after aeration (acclimation of microorganisms) for 2 weeks.

  Table 7 shows that hydrogen sulfide can be removed up to about 80% when LV is 3000 m / h or less. In addition, when LV is too small, there exists a tendency for an apparatus to enlarge, Considering such a point, it is preferable to design so that LV may be 500-3000 m / h.

  <Influence of SV>

  Using the circulating watering type pretreatment device shown in FIG. 1, the SV was changed by changing the aeration rate, and other conditions were the same as those in Table 2 (however, after washing for 2 weeks without a wash) An experiment was conducted to confirm the removal performance of hydrogen sulfide. The hydrogen sulfide used as the gas to be treated was artificially adjusted so that its concentration was kept constant at 130 ppm. Table 8 shows the result of the removal rate of hydrogen sulfide in each aeration SV of hydrogen sulfide after aeration (microbe acclimatization) for 2 weeks.

  Table 8 shows that hydrogen sulfide can be removed up to about 80% when the aeration SV is 3000 / h or less. In addition, when ventilation | gas_flowing SV is too small, there exists a tendency for an apparatus to enlarge, Considering such a point, it is preferable to design so that SV may be 1000-3000 / h.

  The present invention can be used for a gas pretreatment apparatus using a microorganism carrier. In particular, the sulfur-containing atomic compound and the like can be effectively removed from the gas to be treated containing the sulfur-containing atomic compound.

1 is a simplified diagram of a first embodiment of a gas pretreatment apparatus according to the present invention and an apparatus in which a normal biological treatment apparatus is connected thereafter. FIG. It is a simplification figure of 2nd Embodiment of the gas pretreatment apparatus which concerns on this invention. It is a simplification figure of 3rd Embodiment of the gas pretreatment apparatus which concerns on this invention.

Explanation of symbols

1,2,3 High concentration hydrogen sulfide removal gas pretreatment device 11,21,31 Pretreatment tower 121 Circulating water tank 122,22,32 Water tank 13,23,33 Sprinkling pump 14,24,34 Cleaning pump 15,25 , 35 Blower

Claims (4)

A gas pretreatment device for removing the sulfur-containing atomic compound from the gas to be treated containing the sulfur-containing atomic compound, and a biological treatment tower used as a gas main treatment for removing the sulfur-containing atomic compound from the gas to be treated are connected thereafter. Device,
It has a processing tower for circulating the gas to be processed, and inside the processing tower,
A microbial carrier for contacting the gas to be treated in an upward flow;
A watering part for watering the microorganism carrier from above;
Immersion means for immersing the microbial carrier with a cleaning liquid;
A blowing section for blowing air from below to the microbial carrier,
The sprinkling liquid sprayed from above on the microorganism carrier is to use again the sprinkling liquid used for sprinkling ;
When the microbial carrier is blown from below by the blowing unit, the microbial carrier in the packed bed is gas-liquid washed while the level of the washing liquid in the treatment tower is raised and lowered by the immersion means and displaced. A gas processing apparatus comprising the gas pre-processing apparatus.   2. The gas processing apparatus according to claim 1, wherein the microorganism carrier has microorganisms supported on a filler having a particle diameter of 5 to 40 mm.   The gas processing apparatus according to claim 1, wherein the flow rate of the gas to be processed is LV = 500 to 3000 m / hr and SV = 1000 to 3000 / hr. Having a treatment tower for circulating a gas to be treated containing a sulfur-containing atomic compound;
A microbial carrier for bringing the gas to be treated into contact with the inside of the treatment tower in an upward flow;
A watering part for watering the microorganism carrier from above;
Immersion means for immersing the microbial carrier with a cleaning liquid;
A gas pretreatment device that removes the sulfur-containing atomic compound from the gas to be treated, and a fan that blows air from below to the microorganism carrier; and subsequently removes the sulfur-containing atomic compound from the gas to be treated. A cleaning method for a gas pretreatment device in an apparatus connected to a biological treatment tower used as a main gas treatment,
The sprinkling liquid sprayed from above on the microorganism carrier is to use again the sprinkling liquid used for sprinkling;
When the microbial carrier is blown from below by the blowing unit, the microbial carrier in the packed bed is gas-liquid washed while the level of the washing liquid in the treatment tower is raised and lowered by the immersion means and displaced. A method for cleaning a gas pretreatment device.