JP3471711B2 - Filter element holding structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a holding structure for a filter element used in a high temperature exhaust gas dust collector or the like.

[0002]

2. Description of the Related Art A filter element made of a ceramic having excellent heat resistance is used for collecting dust from high-temperature exhaust gas discharged from an incinerator or the like. In particular, recently, a honeycomb having a large filtration area per unit volume is used. Type filter elements are receiving attention. This is one in which both ends of through holes of a ceramic honeycomb structure are alternately plugged, and a wall surface of a thin porous ceramic having a thickness of 1 mm or less is used as a filtration surface.

In a large dust collector, a large number of filter elements are used by mounting them in the mounting holes of the filter support plate, but since the filter support plate is made of metal, large thermal expansion is inevitable during high temperature operation. For this reason, in the case of a normal holding structure, a large thermal stress acts on the filter element, and the honeycomb filter element having a thin wall and low mechanical strength may be damaged. If a loose holding structure is used to avoid the effect of thermal expansion of the filter support plate, gas leakage from the end surface of the filter element will occur.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and allows a filter element to be held on a filter support plate without causing gas leaks and damage due to thermal stress. It was made to provide a filter element holding structure having excellent durability.

[0005]

In order to solve the above-mentioned problems, a filter element holding structure according to the present invention is provided with ceramic holders attached to the outer circumferences of both ends of a ceramic filter element and holding one of them. The filter element is supported by the filter support plate via the two-layer packing, and the filter element is repelled toward the filter support plate by the bellows which is provided outside the other holder and forms a gas flow path. It is what

The filter element is preferably one in which both ends of the through holes of the honeycomb structure are alternately plugged, and the two-layer packing is preferably made of a soft packing and a hard packing. Further, it is preferable that the holder is made of the same ceramic material as the filter element.

According to the filter element holding structure of the present invention, the ceramic filter element receives elastic force by the bellows from one side through the ceramic holders at the outer circumferences of both ends, and the other holder supports the filter. It is pressed against the plate. A two-layer packing composed of a soft packing and a hard packing is interposed between the other holder and the filter support plate to prevent gas leakage. Further, the thermal expansion of the filter support plate in the direction perpendicular to the axis of the filter element is absorbed by the sliding of the two-layer packing. Therefore, it is possible to provide a filter element holding structure that is free from the risk of damage due to gas leakage and thermal stress.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below. FIG. 1 is an overall view showing a structure for holding a filter element according to the present invention, in which 1 is a dust collector can, 2 is an exhaust gas inlet, and 3 is a filter support plate horizontally installed above the dust collector can. The filter support plate 3 is made of metal and has a large number of mounting holes 4. A filter element 5 is held on each mounting hole 4 of the filter support plate 3.

The filter element 5 has, as shown in a partial cross section in FIGS. 2 and 3, alternating plugs 7 at both ends of a through hole 6 of a cylindrical or prismatic ceramic honeycomb structure. It was sealed by. The thickness of the partition walls of the through holes 6 and 6 cans is, for example, 0.9 mm, and the thickness of the outer peripheral wall is 1.
It is as thin as about 8 mm and is made of a ceramic having a small coefficient of thermal expansion such as cordierite. Therefore, it has excellent heat resistance and thermal shock resistance, but has low mechanical strength.

On the outer periphery of both ends of the filter element 5,
Ceramic holders 8, 8 are attached. These holders 8, 8 are preferably made of ceramic of the same quality as the filter element 5 in consideration of thermal expansion. In this embodiment, cordierite press-formed products are used.

FIG. 2 is an enlarged sectional view of the upper end portion of the filter element 5, showing a state in which the holder 8 is attached to the outer periphery of the upper end portion of the filter element 5. In this example, the through holes 6 for one row of the outermost periphery of the filter element 5 are provided.
The holder 8 is attached so as to cover the end surface of the holder. A ceramic seal material 9 seals between the holder 8 and the filter element 5.

Further, on the upper part of the holder 8, a metal fitting 11 having a hanging part 10 for dust seal is sandwiched, and a bellows 12 is formed.
Is attached. The inside of the bellows 12 is a gas flow path 13, and the upper end of the bellows 12 is connected to an exhaust gas pipe 14 as shown in FIG. The bellows 12 has elasticity similar to that of a compression spring, and presses the holder 8 at the upper end of the filter element 5 downward. The metal fitting 11 and the upper end surface of the holder 8 are sealed with a thermally expansive packing 15, and the metal fitting 11 and the outer peripheral surface of the holder 8 are sealed with a rope-shaped packing 16. Although this packing 16 is for preventing play, it can be omitted.

As shown in FIG. 3, the filter element 5
A holder 8 made of ceramics is also attached to the lower end of the with a ceramic sealing material 9 interposed. Two-layer packing is provided between the lower surface of the holder 8 and the filter support plate 3. The packing on the holder 8 side is a soft packing 17, and the packing on the filter support plate 3 side is a hard packing 18. In the two-layer packing made of different materials, the soft packing 17 plays a role of gas seal and thermal expansion absorption, and the hard packing 18 slips when the filter support plate 3 is thermally expanded in the horizontal direction. Has a role to absorb. In addition, a slight step portion 19 is provided around the mounting hole 4 of the filter support plate 3 to regulate the maximum slip amount.

In this embodiment, as shown in FIG. 1, high temperature exhaust gas is introduced into the dust collector can body 1 through the exhaust gas inlet 2, and the exhaust gas is filtered when passing through the partition wall inside the filter element 5, The clean gas is discharged from the exhaust gas pipe 14 via the gas flow path 13 inside the bellows 12. Since the dust in the exhaust gas gradually adheres to the partition wall of the filter element 5, the backwash air is intermittently blown into the bellows 12 from the upper backwash air header pipe 20 via the solenoid valve 21 and the backwash nozzle 22. , Drop the attached dust. The dust that has fallen is collected in the lower hopper 23 of the dust collector can 1.

As a result, the entire inside of the dust collector can body 1 has 60
The temperature becomes 0 to 900 ° C., and the filter support plate 3 greatly expands together with the dust collector can body 1. However, in the present invention, as described above, the filter element 5 is pressed downward by the bellows 12 from the upper part, and the lower part thereof is in close contact with the filter support plate 3 via the two-layer packing, so that the filter element 5 is horizontal. Is due to the sliding of the two-layer packing, and the bellows 12 for the vertical direction.
The elasticity of absorbs thermal expansion. Therefore, the filter element 5 can be stably held without fear of damage due to gas leakage and thermal stress.

As shown in FIG. 1, in this embodiment, the fall prevention wire 2 is attached to the outer circumference of the same portion of each filter element 5.
Surrounded gently by 4. This is to prevent the defect that the filter element 5 is only pressed in the vertical direction and is likely to fall down when receiving a lateral force, but it may be omitted depending on the form of the filter element 5. .

[0017]

As described above, according to the filter element holding structure of the present invention, the filter element having low mechanical strength is prevented from causing gas leakage and damage due to thermal stress. The filter support plate can be stably held. Although the filter element is supported vertically in the above embodiment, it can be supported horizontally by the holding structure of the present invention.

[Brief description of drawings]

FIG. 1 is an overall view showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the upper part of the filter element.

FIG. 3 is an enlarged sectional view of a lower portion of a filter element.

[Explanation of symbols]

1 dust collector can body, 2 exhaust gas inlet, 3 filter support plate, 4 mounting hole, 5 filter element, 6
Through hole of ceramic honeycomb structure, 7 plugging material,
8 ceramic holders, 9 ceramic-based sealing materials, 10 hanging parts for dust seals, 11 metal fittings, 12
Bellows, 13 gas flow path, 14 exhaust gas piping, 15
Thermally expandable packing, 16 Rope-shaped packing, 17
Soft packing, 18 hard packing, 19 steps, 2
0 backwash air header pipe, 21 solenoid valve, 22 backwash nozzle, 23 lower hopper, 24 fall prevention wire

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-1-303397 (JP, A) JP-A-8-117532 (JP, A) JP-A-6-319928 (JP, A) JP-A-8- 164311 (JP, A) JP-A-10-290911 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B01D 46/00-46/54

Claims (4)

(57) [Claims] 1. A ceramic holder is attached to the outer periphery of both ends of a ceramic filter element, and one holder is supported by a filter support plate through a two-layer packing and is provided outside the other holder. A filter element holding structure, wherein a filter element is elastically bulged toward a filter support plate by a bellows forming the gas flow path. 2. The filter element is formed by alternately plugging both ends of through holes of a honeycomb structure.
Holding structure for the described filter element. 3. The filter element holding structure according to claim 1, wherein the two-layer packing comprises a soft packing and a hard packing. 4. The holding structure for a filter element according to claim 1, wherein the holder is made of a ceramic material of the same quality as the filter element.