JP2000210517A - Holding method of ceramic filter, filter pack and filter apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a maintenance method of a ceramic filter capable of holding the ceramic filter certainly even at a time of high temp. use and capable of preventing the damage to the filter caused by vibration and an impact and keeping the sealability between the ceramic filters or between the ceramic filter and an outer frame, a filter pack and a filter apparatus using the filter pack. SOLUTION: In a holding method of a ceramic filter, a single ceramic filter 4 of which the side surfaces are entirely covered with a seal material 2 or a ceramic filter aggregate wherein two or more ceramic filters 4 of which the side surfaces are entirely covered with a seal material 2 are arranged in such a state that the side surfaces are in contact with each other through the seal material is held by a metal outer frame 5 while the seal material 2 is compressed and the thickness of the seal material 2 after compression is set 0.04-0.2 times the min. outer diameter of the end surface of the ceramic filter 4 and at least one side surface of each ceramic filter 4 comes into contact with the metal outer frame 5 through the seal material 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for holding a ceramic filter, a filter pack, and a filter device used for purposes such as collecting dust in gas.

[0002]

2. Description of the Related Art Ceramic filters for dust collection are used in various fields such as chemical, electric power, iron and steel, and automobile-related industries for the purpose of collecting products from high-temperature gas and removing dust from exhaust gas for environmental measures. Used in the field.

[0003] Such a ceramic filter usually has a cylindrical shape for introducing and discharging gas at both end faces,
In addition, from the viewpoint of increasing the filtration area and improving the dust collection efficiency and the like, a configuration having a plurality of cells is often used. In dust collection using a ceramic filter, dust in a high-temperature gas enters from an upstream side, passes through a porous partition, and passes through a hole on a downstream side, and is captured on the surface of a filtration surface.

Further, in order to further improve the filtering performance, dust collecting performance, and the like of a ceramic filter, a honeycomb filter in which a large number of cells are partitioned by partition walls having pores, for example, as shown in FIG. Has a structure in which the upstream side B and the downstream side C are sealed for each cell in reverse, and the high-temperature gas entering from the upstream side B passes through the porous partition wall 20.
Through the hole on the downstream side C, and at that time, the dust in the high-temperature gas is captured on the surface of the partition wall 20.

When a ceramic filter is actually used, a single or two or more ceramic filters are temporarily housed in a metal outer frame to form a filter pack.
This filter pack is further fixed and stored in a storage case via a metal outer frame to form a filter device. In this case, it is necessary to securely hold the ceramic filter with the metal outer frame, and to prevent the unprocessed gas and the processed gas from being mixed with each other, the distance between the ceramic filter and the metal outer frame is reduced. It is necessary to maintain the sealing properties of

In such a situation, as a method of holding the ceramic filter with a metal outer frame, for example, as shown in FIG. A method is known in which an aggregate of ceramic filters arranged in a state where they are in contact with each other via a sealing material 2 is held by a metal outer frame 5 from the entire side surface (Japanese Patent No. 19334425).

[0007]

However, in the method disclosed in Japanese Patent No. 19334425, the coefficient of thermal expansion of the ceramic is small and the coefficient of thermal expansion of the metal is large. As a result of the expansion of only the ceramic filter, the sealing property between the ceramic filters or between the ceramic filter and the outer frame is impaired, and there is a problem that the treated gas is contaminated by the untreated gas. or,
If the outer frame expands, it becomes difficult to hold the ceramic filter securely.If a pressure difference occurs between both ends of the ceramic filter due to sudden load fluctuations or backwashing during operation, the ceramic filter is Move in the direction
Since the end face of the filter and the support member and the like repeatedly contact and separate, there is a problem that the end face of the filter is worn and damaged by vibration and impact.

The present invention has been made in view of such a situation, and an object of the present invention is to be able to securely hold a ceramic filter even when used at a high temperature and to prevent the filter from being damaged by vibration and impact. Another object of the present invention is to provide a ceramic filter holding method and a filter pack capable of maintaining a sealing property between ceramic filters or between a ceramic filter and an outer frame, and a filter device using such a filter pack.

[0009]

That is, according to the present invention, there is provided a method for holding a ceramic filter for holding a cylindrical ceramic filter for introducing and discharging gas at both end faces from a side face by a metal outer frame. A ceramic filter in which a single ceramic filter whose entire side surface is covered with a sealing material or two or more ceramic filters whose entire side surface is covered with a sealing material are arranged in a state where the side surfaces are in contact with each other via the sealing material. Of the ceramic filter is held by a metal outer frame from the entire side surface while compressing the sealing material, and the thickness of the compressed sealing material is 0.04 times or more of the minimum outer diameter of the end face of the ceramic filter, and 0. A ceramic filter holding method in which at least one side surface of each ceramic filter is in contact with the metal outer frame via the sealing material. You.

In the above method, the metal outer frame divided into two or more pieces along the circumference of the end face of the ceramic filter is arranged on the side face of the ceramic filter, and the sealing material is compressed by the pieces. It is preferable to join the divided portions of the fragments. Further, the thickness of the metal outer frame is preferably 5 mm or less.

In the above method, the ceramic filter may have a plurality of cells, and the ceramic filter may be a honeycomb filter. Further, in the above-mentioned method, a part of the metal outer frame may be formed with a falling-off preventing portion formed of a protrusion toward the opening at both open end portions. The portion may form a flange at one open end thereof.

Further, according to the present invention, there is provided a ceramic filter pack holding a ceramic filter by the above method.

Further, according to the present invention, two or more ceramic filter packs held by a metal outer frame having a flange at one of the open ends are provided in a single storage case.
A filter device is provided in which the flange is liquid-tightly mounted on the edge of the hole provided in the storage case and stored. Further, according to the present invention, there is provided a filter device formed by combining two or more ceramic filter packs by joining metal outer frames.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a cylindrical ceramic filter for introducing and discharging gas from both end surfaces is held by a metal outer frame from the side surface. In the case of holding a single ceramic filter, as shown in FIG.
From the entire side surface of the ceramic filter 4 while compressing and holding the sealing material 2 with a metal outer frame 5. The thickness of the sealing material 2 after compression is 0.04 times or more the minimum outer diameter of the end face of the ceramic filter 4.
Make it 0.2 times or less.

When two or more ceramic filters are held, as shown in FIG. 1B, the entire side surface of each ceramic filter 4 is covered with a sealing material 2 and these filters 4 are An aggregate is arranged in a state where they are in contact with each other via the sealing material 2, and the aggregate is
The sealing material 2 is compressed and held by the metal outer frame 5 from the entire side surface, and the thickness of the sealing material 2 after compression is 0.04 times or more the minimum outer diameter of the end face of the ceramic filter 4. 2
It should be less than double.

The reason why the thickness of the sealing material after compression is 0.04 times or more the minimum outer diameter of the end face of the ceramic filter is that even if the metal outer frame is thermally expanded at a high temperature, In order to maintain the sealing property and to securely hold the filter to prevent damage, if the thickness after compression is less than 0.04 times, the sealing material becomes loose when the metal outer frame undergoes thermal expansion, This is because the filter may be damaged, and as a result of repeated movement of the filter due to vibration or the like, the filter may be damaged.

On the other hand, the reason why the thickness of the sealing material after compression is 0.2 times or less of the minimum outer diameter of the end face of the ceramic filter is as follows. Although it is preferable in terms of keeping, the ceramic filter pack is also required to be compact. That is, the volume of the ceramic filter pack is preferably not more than twice the volume of the ceramic filter, and for that purpose, it is necessary to provide the above-mentioned restrictions.

The thickness of the sealing material after compression is more preferably 0.04 times or more and 0.1 times or less the minimum outer diameter of the end face of the ceramic filter, from the viewpoint of emphasizing compactness. More than 0.07 times and not more than 0.2 times are more preferable in consideration of use at higher temperatures.

In the present invention, the “thickness of the sealing material after compression” refers to a thickness when the sealing material is compressed to a predetermined value by a metal outer frame. Also, "Minimum outer diameter of end face"
Refers to the smallest of the outer diameters of the end faces. For example, when the end face is square, the length of one side is equivalent, when the end face is circular, the diameter is equivalent, and when the end face is elliptical, The minor axis corresponds.

As the sealing material, for example, an inorganic fiber having elasticity can be used, but it is preferable to use an alumina / silica fiber.

In the present invention, when holding two or more ceramic filters, at least one side face of each ceramic filter is connected to the metal outer frame via the seal material as shown in FIG. Be touched.
This is because if there is a filter that does not contact either side with the metal outer frame via the sealing material, the difference in thermal expansion increases, so that the sealing property is maintained at a high temperature and the ceramic filter is securely maintained. This is because it becomes difficult.

In the present invention, the thickness of the metal outer frame is 5
mm or less, more preferably 4 mm or less, and even more preferably 3 mm or less. When the thickness is 5 mm or less, it is easy and inexpensive to manufacture a metal outer frame from a steel plate by bending,
In addition, because the ceramic filter is easily thermally deformed at high temperatures, the stress load on the ceramic filter is small, and the ceramic filter is less likely to be damaged.

In the present invention, as shown in FIG. 4 (a), a falling-off preventing portion 7 composed of a protruding portion toward the opening may be formed at both opening ends of the metal outer frame 5. By providing such a fall prevention portion 7, the ceramic filter 4 can be prevented from falling off from the metal outer frame 5.

In the present invention, as shown in FIG. 4B, a flange 8 is provided on one of the open ends of the metal outer frame 5.
May be formed. If such a flange 8 is provided,
When two or more ceramic filter packs 6 held by the metal outer frame 5 are housed in a single storage case 9 to form the filter device 1, as shown in FIG.
The flange 8 can be housed in the edge of the hole 10 provided in the above while being liquid-tightly attached using a gasket or the like, which is convenient.

Further, as shown in FIG.
Are stored in a metal outer frame 5,
It is also possible to join the filter device 1 on the side surface of the metal outer frame 5. With such a configuration, even if the filter is surrounded by another filter, the sealing property can be maintained.

In the present invention, the shape of the end face of the ceramic filter is not particularly limited, and may be, for example, a triangle, a square,
It may be a polygon such as a pentagon, a circle or an ellipse as shown in FIG.

When the ceramic filter is held by the method of the present invention, as shown in FIG. 7, the metal outer frame 5 divided into two or more pieces along the circumference of the end face of the ceramic filter is Placed in fragment 5
a, 5b while compressing the sealing material 2
It is preferable to join the divided portions by welding or the like from the viewpoint of working efficiency.

In the present invention, the ceramic filter may be a simple cylindrical filter having no cell structure, but may have a plurality of cells, or may be a honeycomb filter. . Here, the honeycomb filter is, for example, a filter having a large number of cells 1 partitioned by partition walls 2, as shown in FIG.

If the ceramic filter is held by the method of the present invention, the ceramic filter can be reliably held even when the filter pack and the filter device are used at a high temperature, and the filter can be prevented from being damaged by vibration and impact. The sealing property between the filters or between the ceramic filter and the outer frame can be maintained, and the treated gas can be prevented from being contaminated with the untreated gas.

[0030]

Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiments, but the present invention is not limited to these embodiments.

(Example 1) A honeycomb filter having a square end face of 150 mm on a side and a length of 500 mm was held in a metal outer frame to form a filter pack, workability during holding, and holding of the filter pack. The properties and the volume ratio between the filter pack and the filter were examined. In this embodiment, the thickness (d) of the sealing material after compression was set to be 0.04 times the minimum outer diameter (D) of the filter end face, that is, d / D = 0.04.

The metal outer frame has a thickness of 2 mm and is made of 2tSUS.
A steel plate was used, and a 20 mm-thick aluminum-silica fiber was used as a sealing material. The filter was held as described below.

First, as shown in FIG. 7A, a steel plate 11 having a length of 520 mm and a width of 324 mm (excluding the flange portion and the protrusion portion) provided with a projection constituting the falling-off preventing portion 7 and a flange portion 8. Then, two pieces were cut out. Next, as shown in FIG. 7B, the steel plate 11 is folded in two so as to form a right angle, and the flange portion 8 and the falling-off preventing portion 7 are bent at a right angle in a predetermined direction. The resulting fragments were 5a and 5b. As a result of the bending, the portion where the falling-off preventing portion 7 abuts on the side surface of the steel plate 11 was joined by welding.

Next, as shown in FIG. 7C, the outer frame constituting pieces 5 a and 5 b were arranged from above the sealing material 2 on the honeycomb filter 3 having the sealing material 2 disposed on the entire side surface. Next, as shown in FIG. 7D, the sealing material 2 is compressed to a thickness of 6 mm by the outer frame constituting pieces 5a and 5b,
After the divided portions of the two outer frame constituting pieces 5a and 5b were brought into contact with each other, welding was performed. At this time, the density of the compressed sealing material 2 was made constant.

Next, as shown in FIG. 7 (e), a portion where the falling-off preventing portion 7 is in contact with the side surface portion of the other outer frame constituting piece was joined by welding. Finally, as shown in FIG.
The end face plate 13 was welded to the flange 8 and the end face on the flange side of the filter 3. The end plate 13 is provided for the purpose of fixing to the storage case.

The retention of the above filter pack was examined by the following method. (Testing method of retention) Put the filter pack in an electric furnace and heat it to 500 ° C.
The pressure of m ² was repeatedly applied 10,000 times, and the displacement of the filter from the metal outer frame was examined.

Based on the results obtained in the above test, the retention was evaluated according to the following criteria. In addition, if the holding is ensured, the sealing performance of the filter pack is maintained. When no displacement is observed ... ○ When the displacement is 5 mm or less ... △ When the displacement is 5 mm or more ... ×

The workability at the time of holding was observed from the viewpoint of easiness of bending, and judged based on the following criteria. Good… ○ Some difficulty… △ Some difficulty… ×

The value obtained by dividing the volume of the filter pack by the volume of the filter was defined as the volume ratio between the filter pack and the filter.

D / D value, result of retention test, workability,
Table 1 shows the volume ratio between the filter pack and the filter.

(Examples 2 to 11) As in Example 1,
The honeycomb filter was held by a metal outer frame to form a filter pack, and the workability during holding, the holding ability of the filter pack, and the volume ratio between the filter pack and the filter were examined in the same manner as in Example 1. However, the minimum outer diameter of the end face of the filter, the thickness of the sealing material after compression, the d / D value, the thickness of the metal outer frame, and the like were appropriately changed from the values in Example 1. The results are shown in Table 1.

(Comparative Examples 1 to 4) As in Example 1, the honeycomb filter was held by a metal outer frame to form a filter pack. The retention and the volume ratio between the filter pack and the filter were examined. However, the minimum outer diameter of the end face of the filter, the thickness of the sealing material after compression, the d / D value, the thickness of the metal outer frame, and the like were appropriately changed from the values in Example 1. The results are shown in Table 1.

[0043]

[Table 1]

From Table 1, the d / D value is 0.04 or more,
It can be seen that the filter pack of the example of 0.2 or less had good retention, but the filter pack of the comparative example having a d / D value of less than 0.04 was inferior in retention.
In Examples 1 to 9 using a metal outer frame having a thickness of 5 mm or less, the workability was good, whereas a metal outer frame having a thickness exceeding 5 mm was used. It can be seen that the working examples 10 and 11 were inferior in workability.

[0045]

When the ceramic filter is held by the method of the present invention, the ceramic filter can be securely held even when the filter pack and the filter device are used at a high temperature, and the breakage of the filter due to vibration and impact can be prevented. In addition, the retention between the ceramic filters or between the ceramic filter and the outer frame can be maintained, and the treated gas can be prevented from being contaminated with the untreated gas.
Further, the metal outer frame is set to 5 mm or less, and the metal outer frame divided into two or more pieces along the circumference of the end face of the ceramic filter is arranged on the side face of the ceramic filter, and the sealing material is compressed by the pieces. In addition, by holding the filter by joining the divided portions of the fragments, a ceramic filter pack and a filter device can be manufactured inexpensively and efficiently.

[Brief description of the drawings]

FIG. 1 is a schematic view showing (a) an example and (b) another example of a method for holding a ceramic filter of the present invention.

FIG. 2 is a schematic diagram illustrating an example of a honeycomb filter.

FIG. 3 is a schematic diagram showing an example of a conventional ceramic filter holding method.

FIG. 4 (a) of the ceramic filter pack of the present invention.
It is an example, (b) The longitudinal section which shows other examples, and (c) It is the longitudinal section which shows an example of the filter apparatus of this invention.

FIG. 5 is a longitudinal sectional view showing another example of the filter device of the present invention.

FIG. 6 is a cross-sectional view showing still another example of the method for holding a ceramic filter of the present invention.

FIGS. 7A to 7F are process diagrams showing still another example of the method for holding a ceramic filter of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Filter apparatus, 2 ... Seal material, 3 ... Honeycomb filter, 4 ... Ceramic filter, 5 ... Metal outer frame, 6 ... Ceramic filter pack, 7 ... Dropping prevention part, 8 ... Flange, 9 ... Storage case, 10 ... Hole, 11 ... steel plate, 12 ...
Slit, 13 ... end plate, 20 ... partition, 21 ... cell.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K070 DA07 4D019 AA01 BA05 CA01 CA03 CB01 CB03 CB04 CB06 4D058 JA02 JA03 JA32 JB06 KA01 KA11 KA23 KA25 KA27 KB08 KB15 KC33 KC52

Claims (10)

[Claims] 1. A method for holding a ceramic filter from the side with a metal outer frame, wherein the cylindrical ceramic filter for introducing and discharging gas at both end surfaces is provided. Or an aggregate of ceramic filters in which two or more ceramic filters whose entire side surfaces are covered with a sealing material, and which are arranged in a state where the side surfaces are in contact with each other via the sealing material, are made of metal from the entire side surface. The sealing material is compressed and held by an outer frame, and the thickness of the sealing material after compression is 0.04 times or more and 0.2 times or less the minimum outer diameter of the end face of the ceramic filter. A method for holding a ceramic filter, wherein at least one side of the filter is in contact with the metal outer frame via the sealing material. 2. The metal outer frame divided into two or more pieces along the periphery of the end face of the ceramic filter is disposed on the side face of the ceramic filter, and the sealing material is compressed by the pieces, The method for holding a ceramic filter according to claim 1, wherein the divided portions of the fragments are joined. 3. The method for holding a ceramic filter according to claim 1, wherein the thickness of the metal outer frame is 5 mm or less. 4. The ceramic filter according to claim 1, wherein a part of the metal outer frame has a drop-off preventing portion formed at an opening end thereof, the drop-out preventing portion comprising a projecting portion toward the opening. Retention method. 5. The method according to claim 1, wherein the ceramic filter has a plurality of cells. 6. The method for holding a ceramic filter according to claim 1, wherein the ceramic filter is a honeycomb filter. 7. The method for holding a ceramic filter according to claim 1, wherein a part of the metal outer frame forms a flange at one open end thereof. 8. A ceramic filter pack, wherein the ceramic filter is held by the method according to claim 1. Description: 9. A method according to claim 7, wherein the two or more ceramic filter packs holding the ceramic filter are provided in a single storage case, the flange is provided on the edge of a hole provided in the storage case, A filter device characterized by being housed while being mounted tightly. 10. A filter device comprising a combination of two or more ceramic filter packs according to claim 8, wherein said metal outer frames are joined together.