JP3268065B2 - Dust remover - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust removing device, and more particularly to a high-temperature gas dust removing device which is effective when applied to a coal-fired combined cycle power plant or the like.

[0002]

2. Description of the Related Art FIG. 12 is an overall sectional view showing an example of a conventional dust removing device. In this conventional dust removing device, a plurality of cylindrical filter elements 35 are arranged along the flow direction of the dust-containing gas. The dust-containing gas flowing into the can 1 from the dust-containing gas inlet 2 at the upper portion of the can 1 arranged substantially vertically flows into the cylindrical filter element tube 35 and passes through the tube wall from inside to outside. Dust is removed in the process and clean gas outlet 6
Spill out of. On the other hand, the dust removed from the gas
Is guided to and discharged from the dust hopper 4 below. The upper and lower ends of the cylindrical filter element 35 are the tube sheet 2 respectively.
6 supported.

In such a conventional dust removing device, the dust-containing gas is extracted in a horizontal direction through the tube wall of the cylindrical filter element 35, so that the gas is removed near the outlet end (lower end) 29 of each cylindrical filter element 35. There is almost no downward gas flow velocity, so that a gas flow stagnation occurs in the portion 29, and the cylindrical filter element 3
In the extreme case where dust adheres and accumulates on the inner surface of the element 5, the element 35 may be blocked.

[0004] Of course, in the prior art, the dust adhering to the inner surface of the cylindrical filter element 35 is generally intermittently ejected from the outside of the filter element 35 with high-pressure backwash air to thereby filter the filter element 35. However, as described above, since there is no gas flow near the outlet end 29 of the filter element 35, the dust is not carried out of the pipe, and the once separated dust returns to the filtration process. At that time, there is a fear that the inner surface of the cylindrical filter element 35 is re-adsorbed.

As described above, in the prior art, even if the backwashing of the filter element 35 is performed, there is a problem that the treatment of the attached dust is not always performed. In particular, when backwashing is performed simultaneously over the entire range as in this example, fluctuations in pressure or temperature due to backwash air to the downstream equipment that originally uses the purified gas are adversely affected in a relatively short time. In addition, there is a problem that the dust may be collected due to backwashing on the dust-containing gas side, and re-adsorption in the next filtration step may adversely affect the efficiency of the dust removal device. Was.

Further, as a porous ceramics filter, it is inevitable to increase the size of the device due to the small filtration area per volume of the cylindrical filter element which has been widely used in the past, and this is an obstacle to downsizing the device. There is a side. On the other hand, honeycomb type ceramic body filters have a good track record of removing dust from diesel engine exhaust gas, and have a large filtration area. There is also the question of how to respond.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional apparatus, and is configured so that the backwashing of the filter element can be performed effectively without affecting downstream equipment. It is an object to provide a dust removing device.
Another object of the present invention is to provide a dust removing apparatus having a configuration that allows a thermal expansion difference in removing dust from a high-temperature gas.

Still another object of the present invention is to provide a dust removing apparatus having a structure capable of effectively performing backwashing of a filter element even during dust removal. Another object of the present invention is to provide a dust remover having a configuration capable of preventing vibration in a filter section.

SUMMARY OF THE INVENTION The present invention is intended to solve these problems and to greatly contribute to downsizing and increasing the capacity of a dust removing device and improving dust removing efficiency or reliability.

[0010]

In order to solve the above-mentioned problems, a dust removing apparatus according to the present invention is arranged substantially vertically,
A can body having a dust-containing gas inlet section at an upper portion, a clean gas outlet section and a dust discharge section at a lower portion, and having a refractory wall inside, and a dust-containing gas flow direction from an upper portion to a lower portion in the can body. One or a plurality of filter units each formed by a plurality of honeycomb packs, which are a collection of honeycomb-type porous ceramics filter elements having a dust removal function, are provided, and an inner bottom portion is surrounded by the filter units and the partition duct. A dust-containing gas passage leading to a dust hopper at
A clean gas passage surrounded by a refractory wall inside the filter section, the partition duct and the can body and connected to a clean gas outlet section below the rear portion of the first filter section, and a downflow to a dust hopper at an inner bottom. With a honeycomb pack. In this dust removing device, the honeycomb packs of the respective filter sections may be arranged to face each other with the dust-containing gas flow interposed therebetween, and may be provided in a plurality of stages vertically.

In another dust removing apparatus according to the present invention, in addition to the above-described structure, supporting means for supporting a block of a filter section is supported by a mounting support of a can body, and separation between partition ducts is separated between filter sections. A slidable seal portion is provided between them. As this support means, an arch brick or a support beam may be employed.

Further, in another dust removing apparatus according to the present invention, in addition to the above-described structure, a backwash air pipe seat is provided in a back body of each filter pack and a backwash collecting pipe including a backwash nozzle is provided. The filter pack is provided on the rear side on the clean gas side. Further, in another dust removing apparatus according to the present invention, in the above-described dust removing apparatus, the filter pack is provided with a steady rest in a honeycomb pack storage frame of each filter section.

[0013]

In the dust removing apparatus according to the present invention, the above configuration is employed, so that the dust-containing gas introduced into the upper portion of the can is opposed to the honeycomb packs, which are the aggregate of the honeycomb type filter elements, from the partition duct and are stacked. While flowing down the partition duct of the first filter section, a part thereof is filtered by the filter element and flows through the clean gas passage at the back of the pack to the lower outlet section. The dust-containing gas that has passed through the first filter unit passes through the partition duct, reaches the second filter unit, and the remaining part of the dust-containing gas is filtered.

[0014] In this way, the honeycomb pack at the lowermost stage of the final filter section is not 100% filtered, but passes through the dust-containing gas duct connected to the dust hopper at the lower part of the honeycomb pack to the upper part of the hopper. The required downflow of the dust-containing gas is secured by the downflow honeycomb pack mounted downward, and the dust falling from above falls on its own weight and the dust hopper riding on this downflow. . The clean gas filtered by each filter portion flows sequentially through the clean gas passage surrounded by the can body, the partition duct, and the honeycomb pack, and flows out from the clean gas outlet.

Further, according to the present invention, there is provided a structure in which a supporting means for supporting the block of the filter section on the can body side is provided, and a partition section between the filter sections is cut off and a slidable seal section is provided therebetween. In this case, the difference in elongation of the filter portion can be effectively absorbed.

Further, according to the present invention, a backwash collecting pipe having a backwash nozzle located near a clean gas outlet of each honeycomb filter element is installed in each can of the filter pack in the can body. Inside, backwashing is sequentially performed by setting a timer or the like. The procedure is, for example, to simultaneously backwash the honeycomb packs or the same-stage packs in the filter units which are arranged opposite to each other with a dust-containing gas duct therebetween, and the first filter unit located immediately below the uppermost stage of the first filter unit. When the section is completed, the process proceeds from the upper portion to the lower portion, such as to the uppermost stage of the second filter portion immediately below, and finally becomes a downflow pack, and the backwash cycle is completed.

In this case, the clean gas side is being filtered as a whole, but the area around the pack to be backwashed may be common without being separated from the others. The backwash air flows into the target pack from the pack-based backwash collecting pipe including the backwash nozzles provided for each element beside each honeycomb filter element, and the pack is backwashed effectively. It is a characteristic that

[0018] By such an operation, backwashing is sequentially performed from the uppermost stage and the opposing pack to the lower stage, and the dust separated from the upper portion smoothly falls into the dust hopper along with the gas flow. This solves the problem of reattachment of dust or the problem of adverse effects on downstream equipment due to fluctuations in pressure and temperature on the clean gas side.

Further, in the case where the anti-vibration stay of the filter portion is installed according to the present invention, the honey-comb pack and the dust-containing gas duct to which the honeycomb pack is attached are anti-vibration, so that a stable dust removing action is performed.

According to the above-described operation of the dust removing apparatus of the present invention, the honeycomb filter element has a structural advantage in terms of flexibility and compactness corresponding to a future increase in capacity of a coal-fired combined cycle power plant. As can be easily understood, the size of the filter is about 60 times as large as that of the dust removing device having the same filtration capacity as that of the cylindrical element under the same conditions. % Has been clarified in the applicant's trial design. Therefore, the dust removing device using the honeycomb filter element according to the present invention can flexibly meet various needs in view of such characteristics.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a dust removing apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4, reference numeral 1 denotes a can body which is disposed substantially vertically, has a refractory brick wall 16 built on the inner surface, and a dust-containing gas inlet 2 provided above the refractory brick wall 16 and a clean gas outlet 6 and a dust discharge outlet 19 provided below.
Reference numerals 7, 8, 9 and 10 denote first, second, third and fourth filter portions, which are arranged along the direction of dust-containing gas flow from the upper portion to the lower portion, and are porous ceramic bodies having a dust removing function. A plurality of honeycomb packs 11 (in this example, two rows and three rows per side) as an aggregate of certain honeycomb type filter elements 22 (FIGS. 8 and 9)
(Twelve packs because they oppose each other in steps). This number can be changed according to the filter area.

Each of the filter units 7 to 10 includes a honeycomb pack 1
1. Pack storage hardware and dust-containing gas duct 3 in the center
Is supported at its lower part by an arch brick 18 or a support beam 33 (shown in FIG. 6 (b)).
4 (shown in FIG. 6B) transmits the load to the can 1.

The dust-containing gas duct 3 of each of the filter units 7 to 10
Are cut off at the entrances of the filter portions 7 to 10 and at the lower portion of the arch brick 18 or the support beam 33 of the support portion and engage with the ducts of the upper and lower filter portions. However, the first
At the entrance of the filter unit 7, the partition wall duct 13 is engaged with the dust hopper 4 at the exit of the fourth filter unit 10. These joints are provided with seal packing 20 shown in FIG.
You are using The dust-containing gas duct 3 and the partition wall duct 13 constitute a partition duct according to the present invention.

On the other hand, on the clean gas side, a space surrounded by the lining refractory brick wall 16 of the can 1, the filter pack 11, and the dust-containing gas duct 3 becomes the clean gas passage 5 and is connected to the clean gas outlet 6. .

The dust hopper 4 is formed in a spindle shape with the lower end of the dust-containing gas duct 3 entering the hopper, and is located at the inner bottom of the can 1. The lower end is connected to the dust outlet 19. On the upper surface of the hopper 4, a downflow honeycomb pack 17 is provided.

Further, a backwash facility is provided for backwashing each of the filter units 7 to 10. That is, as can be seen from the cross-sectional view of FIG. 2, the backwashing pipe seat 12 is provided in the can body 1 at the back thereof for each pack of the filter unit, and the backwash nozzle 15 for each filter element of each pack is contained therein. A backwash collecting pipe 14 is provided. As shown in FIGS. 1 and 2, the anti-vibration stays 36 are attached to the central portions of the storage frames of the honeycomb packs arranged in two rows, and there are also six filters / filter portions in the height direction. .

In the configuration described above, the dust-containing gas introduced into the can 1 through the dust-containing gas inlet 2 is supplied to the partition wall duct 1.
3 first flows into the first filter section 7 and descends through the dust-containing gas duct 3 in the middle of the opposing honeycomb packs 11, and a part of them is stored by the honeycomb pack 11. The honeycomb-type filter element 22 is filtered and exits to the clean gas passage 5 surrounded by the refractory brick wall 16, the dust-containing gas duct 3, and the honeycomb pack 11, which are built on the inner surface of the can body 1 behind the pack. To the clean gas outlet 6 to the downstream device while merging with the filtered gas of the other filter section.

The dust-containing gas that has passed through the first filter unit 7 is filtered by the respective filter elements 22 while passing through the dust-containing gas duct 3 to the second, third, and fourth filter units 8, 9, and 10. However, in order to ensure the downflow of the dust-containing gas also in the vicinity of the lower part of the lowermost honeycomb pack of the fourth filter section 10, a downflow honeycomb pack 17 is provided downward on the upper part of the dust hopper 4 connected to the lower part of the duct. Since there is a downflow due to the function, the dust that has descended from above will fall to the dust hopper 4 without stagnation in the vicinity.

The first to fourth filter units 7, 8, 9,
As described above, most of the dust separated by the filter element 22 in the filtration step in the filtration step falls into the dust hopper 4 due to its own weight and the downward flow of the dust-containing gas, but a part of the dust is filtered by the honeycomb filter element. Adheres and deposits on wall surfaces. By applying air pressure in the opposite direction at an optimal time interval, the so-called backwashing is performed, in which these dusts are separated and driven out.

The backwashing in the dust removing apparatus of the present invention is characterized in that the range of simultaneous backwashing is narrow and there is no need to divide the clean gas side into backwashing units. Because of the division, the required amount of air per unit of backwashing, the required time, and the like are reduced, and the backwashing effect is enhanced.

That is, in this embodiment, high-pressure air during backwashing passes through the backwashing pipe seats 12 provided in pack units on the outer can 1 of the honeycomb pack 11 of each filter unit and enters the inside of the can. After entering the continuous backwashing collecting pipe 14, a pulse-shaped pressure wave is applied from the slit-type backwash nozzle 15 provided near the gas outlet side of each honeycomb filter element 22 of the target honeycomb pack 11 for about 0.5 seconds. Let it squirt.

As the backwashing unit, four honeycomb packs 11 at the same stage opposite to each filter unit are employed in this embodiment. Therefore, each of the four filter units has three stages.
One backwash cycle is completed in a total of 13 units including 2 units and 1 unit of the downflow honeycomb pack 17.

By the way, the appropriate cycle required time is 5 to 10 minutes, during which time, like a so-called May rain, frequently occurs at the uppermost stage, the middle stage, the lower stage, the upper stage, the middle stage,.
By performing backwashing sequentially from the upper part to the lower part, the amount of dust peeled and discharged from each element is also averaged, and in addition, the above-mentioned downflow is secured, so that the conventional problems can be solved. Becomes

In the conventional cylindrical filter element 35 (FIG. 12), there is a problem of dust sealing between the tube sheet and the element. However, in the dust removing apparatus of the present invention using the honeycomb filter element 22, the can body 1 has a fireproof inner surface. Since the brick wall is provided, it hardly expands, but since the inside is at a high temperature of about 850 ° C., the seal between the honeycomb filter element 22 and the pack frame 23 and the partition ducts, that is, the vertical expansion of the dust-containing gas duct 3 and the partition duct 13. It is necessary to solve the seal including measures.

The dust seal between the tube sheet and the element is shown in FIG. 8 which is a sectional view of the pack, and FIG. 9 shows a honeycomb type filter element. A flange-like projection is provided on the dust-containing gas inlet side of the filter element 22. On the other hand, a protrusion may be provided on the inner surface of the metal frame 23 of the pack, and a pack seal portion 24 for inserting a seal packing made of a ceramic fiber material therebetween may be provided.

As shown in FIG. 7, two arch bricks 18 for each filter section support the entire load of the filter section to prevent pack expansion under high-temperature gas. Take charge. Since the dust-containing gas duct 3 has a particularly large upward extension, the circular duct connected to the upper portion (the lower portion is also related to the lower filter) is cut off, and a seal packing 20 made of ceramic fiber is also formed as shown in the upper right detailed view. And packing restraint 2
The problem is solved by adopting a slide seal structure provided with the first seal member 1.

As for the arch brick 18, a method using a support beam 33 as shown in FIG. 6B may be used. In this case, the mounting support 3 welded to the can 1
The support beam 33 is supported by 4, and the difference in extension between the can 1 and the support beam 33 can be slid by a long-hole bolt.

Further, a total of six stabilizing stays 36 shown in FIGS. 1 and 2 are provided facing each stage of the filter portion, and the horizontal portions of the honeycomb pack 11 and the dust-containing gas duct 3 to which the honeycomb pack 11 is attached are provided. The direction is steady.

FIG. 10 (a) shows the flow in the honeycomb filter element 22 when dust is removed from the honeycomb filter element 22. The situation in which gas is filtered from the dust-containing gas side to the clean gas side, and the dust is removed from the filter surface on the dust-containing gas side. Shows the situation that remains. Similarly, FIG. 10 (b) shows the movement of the backwash air during backwashing with the same filter, which was adhered to the dust-containing gas side of the filter by a pulse-like pressure wave ejected from the slit type backwash nozzle 15. This shows a situation in which dust separates from the surface and is discharged out of the filter.

FIG. 11 is an explanatory diagram of a method of installing the honeycomb pack 11 which is a member of each filter unit.
It shows that the hoist can be installed on the top of the can and taken in, and that any filter inside can be installed in the same manner and procedure.

The configuration and function of the embodiment have been outlined above, but another feature of the present invention is the flexible response to the increase in the capacity of the entire plant. As a specific numerical value of the present embodiment, the conventional type of dust remover has a diameter of 4.6φ × 23H (m) × 2, whereas the dust remover of the present example has a diameter of 4.4φ × 24H (m) × 1. Even if this is changed to a two-tower system, 4.4φ x 15H
(M) × 2 towers, so compactness is possible, and the filtering area for dust removal is more than 140% in the present embodiment if the conventional method is 100%, and the design has a margin. Has become. This can be said to provide a basis for future capacity expansion of the plant.

[0042]

As described above, according to the present invention, a honeycomb filter element, which is an intensive filter element, is used, and a filter section including a plurality of honeycomb packs obtained by assembling the filter elements in a dust-containing gas flow direction. A plurality of filters are provided in the upstream and downstream directions to ensure that the dust flows down to the dust hopper by always securing the down flow, and the clean gas filtered by the filter element passes through the outer periphery of the dust-containing gas flow path in the can body to each filter section. The structure is such that 100% of the filtered gas is sent from the lower outlet to the downstream device while being merged, so that the blunt efficiency can be increased.

[0043] Simultaneous backwashing of the opposing honeycomb pack or the same-stage pack of the filter section does not require separation of the clean gas space for backwashing, so that it can be divided into many backwash units. Since the pulse-like shock wave from one slit-type nozzle is used for a short time near the gas outlet of each filter element, the backwash effect is large and the amount of air may be small.

Further, since the backwashing is performed orderly from the top to the bottom, there is no problem in maintaining the dust removal efficiency of the dust removing device, and there is also a problem of the separated dust on the dust-containing gas side or a change in the clean gas pressure with respect to the downstream device. It can be said that there is almost no temperature fluctuation. In addition, it can be said that the adaptability to the increase in the capacity of the plant, which is expected in the future, is sufficient because the size can be reduced and the room for the filtration area is large.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a dust removing apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is a sectional view taken along the line BB of FIG. 2;

FIG. 4 is a sectional view taken along the line CC of FIG. 1;

5A and 5B show gas flows in the dust removing apparatus shown in FIG. 1; FIG. 5A is a longitudinal sectional view, and FIG. 5B is an enlarged sectional view along line AA.

FIG. 6 is a drawing showing support means for supporting each filter part of the dust removing apparatus according to the present invention, wherein (a) is a sectional view of an arch brick,
(B) is a perspective view of a support beam.

FIG. 7 is a perspective view showing an internal structure of a filter unit of the dust removing device according to the present invention.

FIG. 8 is a sectional view showing an example of a honeycomb pack used in the dust removing device according to the present invention.

FIG. 9 is a perspective view showing an example of a honeycomb filter element used in the dust remover according to the present invention.

FIGS. 10A and 10B are cross-sectional views illustrating the operation of the honeycomb filter element in the dust removing apparatus according to the present invention, wherein FIG. 10A shows a flow state during dust removal, and FIG. 10B shows a flow state during backwashing.

FIG. 11 shows a dust removing apparatus according to an embodiment of the present invention.
Sectional drawing explaining the situation at the time of a honeycomb pack installation.

FIG. 12 is a sectional view showing a conventional dust removing device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 can 2 dust-containing gas inlet 3 dust-containing gas duct 4 dust hopper 5 clean gas passage 6 clean gas outlet 7 first filter section 8 second filter section 9 third filter section 10 fourth filter section 11 honeycomb pack 12 backwash Pipe seat 13 partition wall duct 14 backwashing collecting pipe 15 backwash nozzle 16 refractory brick 17 downflow pack 18 arch brick 19 dust outlet 20 seal packing 21 packing suppression 22 honeycomb filter element 23 pack metal frame 24 pack seal Reference Signs List 25 fiber material 26 tube sheet 27 high-pressure air source 28 backwash air mother pipe 29 cylindrical filter element outlet 33 support beam 34 mounting support 35 cylindrical filter element 36 steady rest

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hisataka Urata 1-1, Akunouracho, Nagasaki-shi Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (72) Inventor Tetsuya Fujino 1-1-1, Akunouracho, Nagasaki-shi Mitsubishi Heavy Industries, Ltd. (72) Inventor Yuichiro Kitagawa 1-1, Akunouramachi, Nagasaki-shi Inside Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (56) References JP-A-6-262017 (JP, A) JP-A-4-354506 ( JP, A) JP-A-4-326916 (JP, A) JP-A-3-128414 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01D 46/00-46/54 Patent file (PATOLIS)

Claims (4)

(57) [Claims] 1. A dust removing device comprising a can body disposed substantially vertically, having a dust-containing gas inlet portion at an upper portion, a clean gas outlet portion and a dust discharging portion at a lower portion, and a fire-resistant wall inside. One or more honeycomb packs, each of which is composed of a plurality of honeycomb-type porous ceramic body filter elements having a dust removal function and arranged in the same can along the direction of dust-containing gas flow from the upper part to the lower part. A filter portion, a dust-containing gas passage surrounded by the filter portion and the partition duct and leading to a dust hopper at the inner bottom portion,
A clean gas passage surrounded by the filter portion, the partition duct, and a refractory wall inside the can body and connected to a clean gas outlet portion lower than a rear portion of the first filter portion; A dust removing device provided with a pack. 2. A support means for supporting a block of the filter section, which is supported by a mounting bracket attached to the can body and includes a plurality of honeycomb packs having a filter element and a storage section thereof and the partition duct, is provided. 2. The dust removing apparatus according to claim 1, further comprising cutting the partition ducts between the filter sections and providing a slidable seal section therebetween. 3. A clean gas outlet of each of the honeycomb filter elements, wherein a backwashing air pipe seat is provided at a position of the can body corresponding to a rear portion of each of the honeycomb packs, and the honeycomb pack is formed in the can body. 3. The dust removing device according to claim 1, wherein a backwash collecting pipe having a backwash nozzle positioned near the backwash nozzle is installed. 4. The dust removing device according to claim 1, wherein a steady rest of the filter unit is provided for the honeycomb pack storage frame of each filter unit.