JP2007021477A - Gas cleaning apparatus and waste gas treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas cleaning apparatus and a waste gas treatment method capable of efficiently removing particulate such as dust and mist in the waste gas. <P>SOLUTION: The gas cleaning apparatus for collecting the dust or the mist in the waste gas and cleaning sulfur oxides in the waste gas comprises a filter 30 arranged in a gas cleaning tower and consisting of a passage 31 with both ends thereof opened having a plurality of gas distribution passages with both ends thereof opened formed of active carbon fibers extending in the vertical direction, and a water collection unit 40 on a lower end side in the vertical axial direction of the passage 31 of the filter 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a gas purification device and an exhaust gas treatment method for efficiently removing dust, mist, and sulfur oxides in exhaust gas.

Such as coal, heavy oil, the sulfur-containing fuel boilers such as coke, incinerators, the exhaust gas generated by combustion in the combustion furnace firing furnace contains sulfur oxides, SO ₂ is discharged, such as lime-gypsum method Although it is removed by the smoke desulfurization system, in SO ₃ , in the case of sulfuric acid mist having a diameter of 1 μm or less, it is discharged as purple smoke from the chimney.

This removal of purple smoke has been taken from recent environmental protection measures, and various SO ₃ removal methods have been proposed. For example, ammonia is supplied into exhaust gas and removed as ammonium sulfate (Patent Document 1).

However, by supplying ammonia, unreacted ammonia is mixed in the waste water, and its removal becomes a further problem.
Therefore, it has previously been proposed to desulfurize sulfur oxides in exhaust gas using activated carbon fibers (Patent Document 2).

The outline of the proposal of the said patent document 2 is demonstrated using FIG.12 and FIG.13.
As shown in FIG. 12, a conventional exhaust gas purification system includes a boiler 10 that generates steam for driving a steam turbine, a dust collector 121 that removes soot in the exhaust gas 11 from the boiler 10, and a collected exhaust gas. A pusher fan 13 that is supplied into the purification tower 18, a humidification cooling device 14 that cools the exhaust gas 11 before it is supplied to the purification tower 18 and increases the humidity, and a filter 30 that includes a passage 31 that is open at both ends. Cases containing a plurality of stacked packages are arranged inside the two stages 17-1 and 17-2, and the exhaust gas 11 is supplied from the inlet 18 a on the side wall of the tower lower side, and the water 15 is supplied from the upper side of the tower by the water supply unit 16. supply to be discharged purification tower 18 for desulfurization reaction to the SOx in the exhaust gas 11 diluted sulfuric acid (H ₂ SO _4), the purge gas 19 desulfurized from the outlet 18b of the top portion to the outside chimney 0, comprising a sulfuric acid tank 23 for storing the from purification column 18 through the pump 22 dilute sulfuric acid (H ₂ SO ₄₎ 21. A mist eliminator 24 is interposed in the line for discharging the purified purified gas 19 discharged from the purification tower 18 as necessary so as to separate moisture in the gas.

Here, in the boiler 10, for example, fuel f such as coal or heavy oil is burned in a furnace in order to generate steam for driving a steam turbine (not shown) of the thermal power generation facility. The exhaust gas 11 of the boiler 10 contains sulfur oxide (SOx). The exhaust gas is denitrated by a denitration device (not shown), cooled by a gas heater, and then removed by a dust collector 12.
The desulfurization of sulfur oxide in the exhaust gas 11 is efficiently performed by the catalytic action of the activated carbon fibers constituting the filter 30 while supplying a predetermined amount of water 15 in the purification tower 18.

  In this exhaust gas purification system, dilute sulfuric acid 21 obtained in the purification tower 18 is stored in the sulfuric acid tank 23, but gypsum may be obtained by the lime gypsum method using the sulfuric acid.

  As shown in FIG. 13, the passage 31 having both ends opened constitutes a filter 30 by integrating, for example, a flat activated carbon fiber sheet 30-1 and a corrugated activated carbon fiber sheet 30-2. In addition, an extension 32 is formed by extending the lower end of the flat activated carbon fiber sheet 30-1, and the lower edge of the extension is a substantially saw-like height edge 33. The high and low edges 33 prevent water 15 from being blocked by the water 15 supplied to the filter 30 and make the dripping of water uniform.

JP 07-308540 A JP 2003-1112013 A

However, in Patent Document 2, as shown in FIG. 14, the material constituting the filter is activated carbon fiber, and the fibrous filter causes water to stay in the fiber layer in the entire vicinity of the lower end of the filter, A so-called water wall 34 state may be formed. Due to the generation of the water wall 34, there is a problem that the exhaust gas 11 cannot positively contact the activated carbon fiber and the desulfurization performance cannot be maintained.
Further, due to the generation of the water wall 34, the exhaust gas 11 cannot pass through the side wall of the passage, and there is a problem that an effective area for collecting dust and mist is reduced.

  In view of the above problems, an object of the present invention is to provide a gas purification device and a gas treatment method capable of efficiently and stably removing fine particles such as sulfur oxide, dust, and mist in exhaust gas.

  A first invention of the present invention for solving the above-mentioned problems is a gas purification device that collects soot or mist in exhaust gas and purifies sulfur oxides in the exhaust gas. A filter comprising a gas flow passage made of activated carbon fibers disposed at both ends and extending in the vertical direction and having a plurality of gas flow passages, and a water collecting portion provided on the lower end side in the vertical axis direction of the both ends open passage. It is in the gas purification apparatus characterized by this.

  A second invention is a gas purification device that collects dust or mist in exhaust gas and purifies sulfur oxides in the exhaust gas. The gas purification device is disposed in the gas purification tower and extends vertically with both ends open. It comprises a filter comprising a plurality of open end passages having a plurality of gas flow passages made of activated carbon fibers, and a package in which a plurality of the open end passages are stacked, and has a predetermined interval in a case for housing the package. The gas purifier is characterized in that a partition portion is formed.

  According to a third aspect of the present invention, there is provided the gas purification device according to the second aspect, wherein the interval between the partition portions is not less than 5 times and not more than 20 times the passage opening maximum diameter.

  According to a fourth aspect of the present invention, there is provided the gas purification apparatus according to the second or third aspect, wherein a water collecting portion is provided on a lower end portion side in the vertical axis direction of the both-end open passage.

  A fifth invention is the gas purification apparatus according to the first or fourth invention, wherein the water collecting portion is in a sheet or mat shape or a mesh structure.

  A sixth invention is the gas purification apparatus according to any one of the first to fifth inventions, wherein one end of the both-end open passage is closed by a closing portion.

  A seventh invention is the gas purification apparatus according to any one of the first to sixth inventions, wherein the filter includes a flat sheet and a corrugated sheet.

  The eighth invention is the seventh invention according to the seventh invention, comprising the flat sheet and the corrugated sheet, and the first passage in which either the lower end or the upper end of the passage is closed; Gas purification, characterized in that at least a part or all of both corrugated sheets are integrated with a second passage having both ends open, which is composed of a flat sheet and a corrugated sheet. In the device.

  According to a ninth invention, in any one of the first to eighth inventions, a case in which a package in which a plurality of the filters are stacked is housed in the gas purification tower is arranged with a plurality of stages at a predetermined interval. It is in the gas purification apparatus characterized by becoming.

A tenth aspect of the present invention is an exhaust gas treatment characterized by using the gas purification device according to any one of the first to ninth aspects of the invention to collect soot and SO ₃ mist in the exhaust gas and remove SO _2. Is in the way.

According to this invention, the water of a filter can be actively discharged | emitted by a water collection part, and the gas purification process in waste gas can be performed stably. Further, the water collecting unit can actively collect water mist and SO ₃ mist of submicron or more in the exhaust gas, thereby preventing the filter from being in a water wall state.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

A gas purification apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of a filter according to the present embodiment, FIG. 2 is a perspective view of a filter packaged in a case, and FIG. 3 is a schematic view of collecting fine particles (mist) in gas. FIG. 4 is a schematic diagram of a filter including a passage having a blocking portion.
As shown in FIG. 1, the gas purification apparatus according to this embodiment is a gas purification apparatus that collects dust or mist in exhaust gas and purifies sulfur oxides in the exhaust gas. A filter 30 including a plurality of gas flow passages made of activated carbon fibers disposed at both ends and extending in the vertical direction, and a plurality of gas open passages (hereinafter referred to as “passages”) 31; The water collection part 40 is provided in the lower end part side.

  As shown in FIG. 2, a plurality of the filters 30 are stacked in the vertical direction to form a package that does not leak gas, and the package 30 is housed in a case 41.

  The water collecting part 40 may have any one of a sheet-like structure, a mat-like structure, and a net-like structure, for example, and may have a good water discharging property without affecting the flow of the exhaust gas. .

  For example, a synthetic fiber such as polyvinylidene chloride synthetic fiber that has been curled into, for example, a spring shape and arranged in a bulky shape to form a three-dimensional network structure is a good example of such a water discharging property. It can be illustrated.

  Since this water collection part 40 can discharge | emit the water stayed in the lower end part vicinity of the filter 30 actively, generation | occurrence | production of the water film by the purification | cleaning of gas like the past can be prevented. Thereby, since there is no desulfurization inhibition by the water wall in the surface of the filter 30, gas can be purified stably over a long period of time.

Further, as shown in FIG. 3, the water collection unit 40 includes soot 61 contained in the exhaust gas 11, water mist (small particle size) 62, water mist (large particle size) 63, SO _3. Among mist (small particle size) 64, SO ₃ mist (large particle size) 65, etc., dust 61 having a relatively large particle size, water mist (large particle size) 63, and SO ₃ mist ( 65 having a large particle size).

  Here, a thing with a large particle size means a thing exceeding submicron (1 micrometer-0.1 micrometer), and a thing with a small particle diameter means a thing below submicron.

The water mist is formed in a large amount in the exhaust gas 11 by water injection to cool the exhaust gas in a humidified cooling device, and the suspended fine particles in the exhaust gas serve as a nucleus for the exhaust gas. 11 is formed in a large amount. Similarly, the SO ₃ mist also has a large particle size. Therefore, water mist 63 and SO ₃ mist 65 of submicron or more are actively collected by the water collection unit 40.

As a result, submicron or larger water mist 63 and SO ₃ mist 65 are positively collected by the water collecting section 40, and as a result, water mist having a large particle size adheres to the surface of the filter 30 and the water wall is blocked. It can be prevented from forming.

As a result, the removal efficiency of sub-micron SO ₃ mist 64, which is a problem of purple smoke, is improved.

In addition, the present invention is not limited to a both-end open passage as a filter, and a filter composed of a both-end open passage and a partially-closed passage so as to close a part of the end of the passage, The exhaust gas may be introduced from the both-end open passage into the closed passage due to the pressure difference, and dust and mist (SO ₃ mist) in the exhaust gas 11 may be actively collected when passing through the wall of the passage. An example of this is shown in FIGS.

In FIG. 4, a blocking portion 35 is provided on the lower end side of the filter 30.
By closing part of the gas introduction side of the both-end open passage 31 shown in FIG. 1 with the closing portion 35, a pressure difference is generated between the both-end open passage 31 and the passage having the closing portion 35. Then, the amount of gas that moves to the closed passage in the exhaust gas 11 that passes through the passage 31 that is open at both ends increases, and the removal efficiency of, for example, SO ₃ mist that is fine particles is dramatically improved by the filter effect at the time of the transition of the gas. To improve.

Further, as shown in FIG. 5, a gas introduction side blocking passage 30 </ b> A which is a first passage having a blocking portion 35 at the lower end end thereof, which includes a plate filter 30-1 and a triangular wave plate filter 30-2. The gas discharge side closed passage 30B, which is the second passage having the closed portion 35 at the upper end, is formed of the plate filter 30-1 and the triangular wave plate filter 30-2, and the convex portion of one filter. Alternatively, the filter 36 may be formed by integrating the concave portions of the other filter so as to face each other. By using such a filter 36, the exhaust gas 11 introduced from the open passage passes through the side wall of the gas discharge side blocking passage 30B and the side wall of the gas discharge side blocking passage 30B twice, and SO ₃ Mist collection efficiency is improved. As described above, the filter 36 shown in FIG. 5 forms the closed portions 35 alternately on the lower end portion side and the upper end portion side, so that the collection efficiency of dust or mist increases.

  The exhaust gas purification system of FIG. 6 has the same configuration as the exhaust gas purification system shown in FIG. 10 described above, and the same members are denoted by the same reference numerals, and redundant description is omitted. As shown in FIG. 6, the exhaust gas purification system according to this embodiment includes the three-stage first case 41-1, second case 41-2, and third case 41-in the purification tower 18 that purifies the exhaust gas 11. 3 is stored with a predetermined interval, and the first water collecting part 40-1 is interposed between the first case 41-1 and the second case 41-2, and the second water collecting part 40-2 is interposed between the second case 41-2 and the third case 41-3.

  Here, in FIG. 6 shown in the present embodiment, the lower ends of the first and second water collecting portions 40-1 and 40-2 are in contact with the upper ends of the second case 41-2 and the third case 41-3. However, it may be arranged with a predetermined gap without contact.

As a result, even when the case 40 containing the filter 30 is installed in a plurality of stages, the water can be discharged well, and the exhaust gas can be stably purified over a long period of time.
Note that the number of stages to be installed is about 2 to 15 and is appropriately changed according to the amount of mist in the exhaust gas to be purified and the amount of processing gas.

  Moreover, although the exhaust gas 11 from the boiler 10 was illustrated in the present Example, the exhaust gas used as the purification | cleaning object of this invention is not limited to this, What is discharged | emitted from a gas turbine, an engine, a gasification furnace, and various incinerators It is good.

  The exhaust gas purification apparatus according to the present invention can purify not only exhaust gas containing sulfur such as coal, but also exhaust gas containing other harmful dust and harmful mist.

A gas purification apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 7 is a schematic view of a gas purification device according to a conventional example, and FIG. 9 is a plan view of a case that houses a packaged filter according to a conventional example. FIG. 8 is a schematic view of the gas purification apparatus according to the present embodiment, FIG. 10 is a plan view of a case for storing the filter according to the present embodiment, and FIG. It is a schematic diagram which shows the mode of discharge | emission.

As shown in FIG. 7, the conventional filter 30 is housed in a case 41 as shown in FIG. 9 in a state where the width (W ₁ ) is widened (for example, W ₁ = 500 mm).
In such a case, since the width of the filter 30 is wide, the discharge effect by the water droplets 46 as shown in FIG. 11 was not good.

In this embodiment, as shown in FIG. 10, a partition wall 45, which is a partition part, is formed in a case 42 that houses a package formed by stacking a plurality of filters, and is shown in FIG. Thus, the width (W ₂ ) of the filter 30 is made narrow.

Here, in this invention, the space | interval D of the said partition part is made into 5 times or more and 20 times or less of the channel opening maximum diameter d of the channel | path 31. FIG. This is because when the distance D is 20 times or more of the passage opening maximum diameter d of the passage 31, the effect of removing water is not good, and there is a problem that a water wall is formed.
For example, when the opening diameter of the filter 30 is 6 mm, the interval D is particularly preferably about 50 mm.

  As a result, according to the present embodiment, the width of the filter 30 is narrowed and both ends thereof are brought into contact with each other by the wall or the partition portion. Therefore, the filter 30 is transmitted along the side wall by the water droplet 46 as shown in FIG. Therefore, the exhaust gas can be purified stably over a long period of time.

  Further, the wall 41 and the partition portion 45 may be formed with a film of a synthetic resin (for example, polytetrafluoroethylene) obtained by polymerization of, for example, an olefin containing fluorine that has particularly good water repellency.

  Further, in the second embodiment, the lower end portion is formed with a saw-like height portion 33 as in the prior art, but the present invention is not limited to this, and the height portion 33 may be removed. . Or you may make it exhibit the synergistic effect by combining the Example 1 and Example 2 by providing the water collection part 40 of Example 1. FIG.

  As described above, the exhaust gas purifying apparatus according to the present invention improves the water discharge performance and can collect a large mist in the exhaust gas, and can be used for gas purification stably over a long period of time. Is suitable.

It is a schematic diagram of the filter which concerns on a present Example. It is the perspective view which stored the thing which packaged the filter in the case. It is a schematic diagram of the filter which concerns on a present Example. It is a schematic diagram of the filter which consists of a channel | path which has the obstruction | occlusion part which concerns on a present Example. FIG. 6 is a structural diagram of another filter in which passages having a blocking portion are integrated. It is the schematic which shows an exhaust gas purification system. It is a schematic diagram of the gas purification apparatus which concerns on a prior art example. It is a schematic diagram of the gas purification apparatus which concerns on a present Example. It is a top view of the case which accommodates what packaged the filter which concerns on a prior art example. It is a top view of the case which accommodates what packaged the filter which concerns on this implementation. It is a schematic diagram which shows the mode of the water discharge of a filter. It is the schematic which shows the conventional gas purification system. It is a perspective view of the conventional filter. It is a schematic diagram of the filter in which the conventional water wall was formed.

Explanation of symbols

11 exhaust gas 18 purification tower 30 filter 31 passage 40 water collecting part 41 case 42 case

Claims (10)

A gas purification device that collects dust or mist in exhaust gas and purifies sulfur oxides in exhaust gas,
A filter comprising a plurality of open end passages disposed in the gas purification tower and having a plurality of gas flow passages made of activated carbon fibers extending in the vertical direction with both ends open;
A gas purification apparatus, wherein a water collecting part is provided on a lower end part side in a vertical axis direction of the both ends open passage. A gas purification device that collects dust or mist in exhaust gas and purifies sulfur oxides in exhaust gas,
A filter comprising a plurality of open end passages disposed in the gas purification tower and having a plurality of gas flow passages made of activated carbon fibers extending in the vertical direction with both ends open;
A package formed by laminating a plurality of open ends on both ends, and
A gas purification apparatus, wherein a partition part is formed at a predetermined interval in a case for housing the package. In claim 2,
The gas purification apparatus characterized in that an interval between the partition portions is 5 to 20 times the maximum diameter of the passage opening of the passage. In claim 2 or 3,
A gas purification apparatus, wherein a water collecting part is provided on a lower end part side in a vertical axis direction of the both ends open passage. In claim 1 or 4,
The gas purifier according to claim 1, wherein the water collecting portion is in a sheet shape, a mat shape, or a mesh shape. In any one of Claims 1 thru | or 5,
One end of the both-end open passage is closed by a closing part, A gas purification device characterized by things. In any one of Claims 1 thru | or 6,
The gas purification apparatus characterized in that the filter comprises a flat sheet and a corrugated sheet. In claim 7,
A first passage that is composed of the flat sheet and the corrugated sheet, and that closes either the lower end or the upper end of the passage;
A second passage having both ends open, comprising the flat sheet and the corrugated sheet,
A gas purification apparatus, wherein at least a part or all of both corrugated sheets are integrated with each other. In any one of Claims 1 to 8,
A gas purification apparatus comprising a plurality of stages in which a plurality of stacked filters are housed in the gas purification tower at predetermined intervals. An exhaust gas treatment method comprising collecting dust and SO ₃ mist in exhaust gas and removing SO ₂ using the gas purification device according to claim 1.

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