JP3416417B2 - Honeycomb type ceramic filter - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a honeycomb type ceramic filter applied to a fluidized bed boiler or the like.

[0002]

2. Description of the Related Art In a fluidized bed boiler that generates combustion gas to be sent to a gas turbine for re-combustion, it is necessary to remove ash in the combustion gas with a cyclone or a filter before sending it to the gas turbine. Honeycomb type ceramic filters are generally used.

This honeycomb type ceramic filter is housed in a steel pack 6 as shown in FIG.
As shown in (b), the rib 3 provided on the lower portion of the filter body 1 is attached to the pack 6 by the pressing metal members 8 and 9 and the bolt 10.
The combustion gas containing ash enters from the lower part and is filtered by the filter body 1.

In the conventional honeycomb type ceramic filter, the filter body 1 has a structure shown in FIGS. 5 (a), 5 (b) and 5 (c).
As shown in FIG. 3, the inside is partitioned into a lattice shape to form holes 1a, and each hole 1a has a blind plug 3 at the top or bottom.
Was provided and the necessary filtration area was secured by arranging them alternately.

The blind plug 3 is formed by molding and sintering the filter body 1 provided with a grid-shaped partition, and then filling the end portion of the hole 1a with clay, which is a raw material for ceramics, and sintering the clay again. Was there.

[0006]

In the honeycomb type ceramic filter used for removing the ash of the combustion gas generated by the fluidized bed boiler, the ash accumulates on the surface of the filter as the time of use elapses, and the pressure loss increases. Therefore, this ceramic filter needs to be periodically backwashed by applying a pressure in the opposite direction to that during normal operation to remove the adhered ash, as shown in FIG. 4 (c).

The backwashing operation is carried out by blowing backwashing air to the ceramic filter. However, the backwashing pressure must be instantaneously applied during the backwashing operation.
Dynamic pressure and vibration force due to backwash air act on the ceramic filter.

In the conventional honeycomb type ceramic filter, since the filter body is fixed to the pack through the ribs as described above, during backwashing, as shown in FIG. There is a problem that the maximum bending stress is generated at the rib 2 and the root of the filter body 1 and the rib is damaged from the root.

As a countermeasure against this, it is conceivable to increase the thickness of the outermost wall of the filter body. However,
In this case, the bending strength can be increased,
There was a problem that the pressure loss of the filter also increased.

In order to solve the above problems, the present invention intends to provide a filter having a structure that does not affect the filtration pressure loss of the filter and has a strength that can withstand this bending.

[0011]

[Means for Solving the Problems]

(1) The invention as set forth in claim 1 is a filter body in which ribs fixed to the pack are arranged on the outer peripheral portion of the lower portion thereof and a lattice-like partition is provided inside to form a plurality of holes in the vertical direction. In a honeycomb ceramic filter provided with a blind plug at the lower end of every other hole on the front, rear, left and right and an upper end of the other holes, the blind plug at the lower end of the hole has It is characterized by being formed by clay embedded in the lower end of the hole as a depth deeper than the thickness of the rib.

In the present invention, unlike the conventional device in which the depth of the blind plug is shallower than the thickness of the rib, the blind plug is deeply embedded so that the top of the blind plug is sufficiently above the upper surface of the rib. I have to.

Therefore, the blind plug bears the bending load acting on the filter body during backwashing, and the strength against bending stress can be improved with almost no increase in pressure loss of the filter.

(2) The invention according to claim 2 is the honeycomb type ceramic filter according to the invention (1), wherein after the blind plug at the lower end of the hole fills clay in the lower end of the hole, It is characterized in that it is formed by pressing the top of the clay from the upper end of the hole.

In the present invention, as in the case of the above-mentioned invention (1), since the clay is embedded in the lower end portion of the hole and the top of the clay is pressed from the upper end portion of the hole, it is different from the above-mentioned invention (1). The close contact between the blind plug and the filter body is improved, and the strength against bending stress can be further improved.

(3) The invention according to claim 3 is the honeycomb type ceramic filter according to the invention (2), wherein the pressing means for the top of the clay embedded in the lower end of the hole has a flat tip. It is characterized in that it is a push rod formed into a shape.

In the present invention, since the top of the clay embedded in the lower end of the hole is pressed by the push rod having the flat tip, the contact between the blind plug and the filter body is improved as compared with the above invention (1). And the strength against bending stress can be further improved.

(4) The invention according to claim 4 is the honeycomb type ceramic filter according to the invention (2), wherein the pressing means for the top of the clay embedded in the lower end of the hole has a spherical tip. It is characterized in that it is a push rod formed into a shape.

In the present invention, since the top of the clay embedded in the lower end of the hole is pressed by the push rod having the spherical tip, the degree of adhesion between the blind plug and the filter body is higher than in the above invention (1). It is possible to further improve the strength against bending stress.

Further, in the above invention (3), the angle formed by the top of the blind plug and the wall of the filter body is a right angle, and stress may concentrate on this portion. Since the tip of the rod is spherical, the top of the blind plug is recessed into a spherical shape and has a smooth mating shape, so that stress concentration in this portion can be avoided.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A honeycomb type ceramic filter according to a first embodiment of the present invention will be described with reference to FIG.

In this embodiment shown in FIG. 1, a brim-shaped rib 2 fixed to the pack is arranged on the outer periphery of the lower portion, and a grid-like partition is provided inside to form a plurality of holes 1a in the vertical direction. The filter body 1 that has
In a honeycomb type ceramic filter in which clay, which is a raw material for ceramics, is embedded in the lower end portion of a and the upper end portion of other holes 1a to form blind plugs, the depth of embedding of clay is compared with the thickness of the rib 2. The blind plug 3a is formed by embedding clay in the lower end of the hole 1a and sintering it to a sufficiently deep depth.

In the above, the blind plug 3 at the lower end of the hole 1a
Since the depth of the embedding a is made deep so that the top of the blind plug 3a is sufficiently higher than the upper surface of the rib 2, the blind plug 3a bears the bending load acting on the filter body 1 during backwashing. The strength against bending stress acting on the filter can be improved.

Next, a honeycomb type ceramic filter according to a second embodiment of the present invention will be described with reference to FIG. In the present embodiment shown in FIG. 2, in the honeycomb ceramic filter according to the first embodiment, after the clay is embedded from the lower end of the hole 1a, the push rod 4 having a flat tip from the upper end of the hole 1a is inserted. The blind plug 3b is formed by pressing the top of the clay that has been embedded.

In this embodiment, as in the first embodiment, clay is embedded in the lower end of the hole 1a, and then the hole 1a is formed.
Since the push rod 4 is inserted from the upper end of the plug to apply pressure, the degree of contact between the blind plug 3b and the filter body 1 is improved as compared with the first embodiment in which the top of the blind plug is convex, and the blind plug 3b as a whole. Can effectively share the load, and the strength against bending stress can be further improved as compared with the first embodiment.

Next, a honeycomb type ceramic filter according to a third embodiment of the present invention will be described with reference to FIG. In the present embodiment shown in FIG. 3, in the honeycomb type ceramic filter according to the second embodiment, the top of the clay is pressed by the push rod 5 having a spherical tip, and the blind plug 3c is provided.
Are formed.

In the present embodiment, since the top of the clay is pressed by the push rod 5 having a spherical tip, the above second
Unlike the embodiment, a spherical recess is formed at the top of the blind plug 3c.

In the case of the second embodiment, since the tip of the push rod 4 is flat, the angle formed by the tip of the blind plug and the wall of the filter body 1 becomes a right angle, and stress may concentrate on this portion. In the case of the present embodiment, since the top of the blind plug 3c is spherically shaped and has a smooth fitting shape, stress concentration at this portion can be avoided, and the strength can be further improved as compared with the second embodiment. It was

[0029]

In the honeycomb type ceramic filter of the present invention, the ribs fixed to the pack are provided at the lower ends of a plurality of holes vertically formed in the inside of the filter main body having the lower peripheral portion. The blind plug is made of clay that is embedded deeper into the lower end of the hole than the rib thickness, so the blind plug bears the bending load that acts on the filter body during backwashing. However, the strength can be improved with almost no increase in pressure loss.
After the clay was embedded in the lower end of the hole, the top of the clay was pressed from the upper end of the hole, for example, by pressing with a push rod having a flat or spherical tip to form a blind plug. In particular, when a push rod having a spherical tip is used, it is possible to avoid stress concentration at the joint between the filter body and the blind plug.

[Brief description of drawings]

FIG. 1 is a side sectional view of a honeycomb type ceramic filter according to a first embodiment of the present invention.

FIG. 2 is a side sectional view of a honeycomb type ceramic filter according to a second embodiment of the present invention.

FIG. 3 is a side sectional view of a honeycomb type ceramic filter according to a third embodiment of the present invention.

[Fig. 4] Fig. 4 is an explanatory view of a honeycomb type ceramic filter used for a fluidized bed boiler, (a) shows a state of being mounted in a pack, (b) shows details of a mounting part to the pack, and (c) shows a state of backwashing. It is explanatory drawing of the flow of backwash air.

5A and 5B are explanatory views of a conventional honeycomb type ceramic filter, where FIG. 5A is a perspective view from above, FIG. 5B is a perspective view from below, FIG. 5C is during normal operation, and FIG. It is explanatory drawing of the bending stress which sometimes acts.

[Explanation of symbols]

1 Filter body 2 ribs 3a, 3b, 3c Blind plug 4 Push rod (planar tip) 5 Push rod (spherical tip) 6 pack 7 pack wall 8 Rib top holding hardware 9 Lower rib holding hardware 10 volts 11 packing 12 Clean gas duct 13 Inner cylinder 14 Backwash inner cylinder

Continuation of front page (56) Reference JP-A-58-45715 (JP, A) JP-A-4-27406 (JP, A) JP-A-7-136438 (JP, A) JP-A-61-136413 (JP , A) JP-A-8-281034 (JP, A) JP-A-8-187435 (JP, A) JP-A-62-57624 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB) Name) B01D 39/00 B01D 46/00 F01N 3/00

Claims (4)

(57) [Claims] 1. A filter main body is provided with a rib fixed to a pack, which is provided on an outer peripheral portion of a lower portion of the pack, and which is internally provided with a grid-like partition to form a plurality of vertical holes. In a honeycomb ceramic filter in which blind plugs are provided at the lower end of every other hole and the upper ends of other holes, the blind plug at the lower end of the hole has a deeper embedded depth than the thickness of the rib. A honeycomb type ceramic filter characterized by being formed by clay embedded in a lower end portion of a hole as a depth. 2. The honeycomb type ceramic filter according to claim 1, wherein the blind plug at the lower end of the hole presses the top of the clay from the upper end of the hole after burying the clay in the lower end of the hole. A honeycomb-type ceramic filter formed by: 3. The honeycomb type ceramic filter according to claim 2, wherein the pressing means for the top of the clay embedded in the lower end of the hole is a push rod having a flat end. Honeycomb type ceramic filter. 4. The honeycomb type ceramic filter according to claim 2, wherein the pressing means for the top of the clay embedded in the lower end of the hole is a push rod having a spherical tip. Honeycomb type ceramic filter.