JP2000000415A - Seal structure of ceramic filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the sealing performance and to decrease the gas concn. in a seal structure of the ceramic filter of a dust collector applied to a coal- gasified combined power generating system by preventing the gas from being leaked from the joint between a ceramic tube and a weight sleeve. SOLUTION: A weight sleeve 3 is placed on the upper end of a ceramic tube 1 through a gravity seal 2 and surrounded by a main body 4, and a sealing part 5, a cylindrical ring 13 and an upper cylindrical member 15 are integrally connected by bolts and nuts 16 within the main body 4 through the respective flange faces. A sealing member 6 is inserted between the outer periphery of the tip of the weight sleeve 3 and the inner periphery of the sealing part 5 and made slidable through the sealing member 6 when a thermal elongation difference is produced between the weight sleeve 3 and its outer structure. A mount surface 3a is formed on the weight sleeve 3, and an elastically energized coil spring 20 is inserted between the slope 3a and the flange face 5a of the sealing part 5 to press the weight sleeve 3 and the lower gravity sleeve, and the gas is never leaked from the abutment part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing structure for a ceramic filter, and is applied to a support portion of a long, porous ceramic tube for collecting high-temperature gas, so as to prevent gas leakage from a tip portion of the ceramic tube. Things.

[0002]

2. Description of the Related Art An integrated coal gasification combined cycle system (hereinafter referred to as I)
(Hereinafter referred to as GCC), it is necessary to supply a coal gas having a low dust concentration to a gas turbine, and the performance of the technology depends on a ceramic filter (precision dust removal) technology. Therefore, the ceramic filter is required to have high dust collection performance and to be manufactured at low cost. This type of ceramic filter is used in a pressurized fluidized bed boiler (PFBC), and the gas temperature in the PFBC is 850 ° C. or more. In the PFBC, a ceramic filter is used because a conventional device such as a bag filter cannot be used. ing.

The problem with ceramic filters is that
Ceramics, unlike conventional metals and bag filter materials, are inflexible and do not stretch because they do not elongate, so they need to be devised to absorb thermal elongation, especially at the joints with metals having different coefficients of thermal expansion. In order to apply such a ceramics filter to the IGCC, the gas temperature is 450 ° C., which is lower than 850 ° C. of the PFBC, and the effect of thermal elongation is small as compared with the performance of the ceramic filter in the PFBC.

However, the outlet gas concentration in IGCC is much more severe than that of PFBC due to the requirements of the gas turbine side, and must be suppressed to 1 mg / Nm ³ or less as compared with 10 mg / Nm ^{3 of} PFBC, and the sealing performance is greatly improved. Is required. Still another requirement is that the gas in the IGCC has a high sulfuric acid concentration, and it is necessary to adopt a structure taking into account sulfuric acid corrosion.

FIG. 5 shows the structure of a dust collector used in a conventional PFBC, and FIG.
(B) is a diagram showing the cassette pack in (a). In the drawing, reference numeral 30 denotes a main body of the dust collecting apparatus, in which a number of cassette packs 40 are stored, and in each cassette pack 40, a backwash tube 41 and a number of ceramic tubes 31 are arranged vertically. ing. (B) shows only one ceramic tube 31 in the cassette pack 40.

FIG. 6 is an enlarged sectional view of the ceramic tube 31 shown in FIG. In the figure, the ceramic tube 31
Is formed by joining two tubes 31a and 31b. A metal tube (loading sleeve) 33 is inserted into the upper portion of the tube, and a seal portion 35 is attached to the outer periphery of the upper portion of the metal tube 33. The metal tube 33 is supported by the upper tube sheet 34. The lower end of the ceramic tube 31 is placed in contact with the receiving portion 36 of the lower tube sheet 32.

FIG. 7 shows a detail of a portion C in FIG. 6. On the upper surface of the ceramic tube 31, a metal tube 33 having substantially the same sectional diameter as the ceramic tube 31 and having a larger thickness is used as a sheet packing 37 as a sealing member. Placed via
This metal tube 33 is connected to a seal portion 35 provided on an upper tube plate 34 as an upper partition tube plate.

The metal tube 33 is simply placed on the upper surface of the ceramic tube 31 via a sheet packing 37 which is formed by knitting ceramic fibers and sewing the ring. Around the outer periphery of the metal tube 33, a metal ring 35a in which a horizontal flange portion 35a 'is fixed to the upper tube sheet 34 is arranged. In the gap between the metal ring 35a and the metal tube 33,
A member 38 in which a ceramic fibrous filler and a metal ring are combined is inserted.

During normal operation, gas enters the ceramic tube 31 as indicated by R ₁ in the above-described structure, flows out of the ceramic tube 31 to the outside, dust is captured inside, falls down, and falls outside the body. can be taken out in, at the time of backwashing gas from the backwash pipe passes from ceramic tube 31 outwardly as indicated by R ₂ to the inside, to the Remove the dust adhering to the inner wall of the ceramic tube 31.

[0010]

As described above, the metal tube (loading sleeve) 33 is in contact with the tip of the ceramic tube 31 via the sheet packing 37, and the ceramic tube 31 is still mounted. Since this is a ceramic tube used for PFBC, the gas temperature of PFBC is as high as 850 ° C.
This is because the metal weight sleeve 33 and the ceramic tube 31 cannot be brought into mechanical contact with each other so that no gap is formed. In the ceramic tube having such a structure, a thermal expansion difference occurs during operation, and the weight sleeve 33 needs to slide through the seal portion 5. However, if the seal portion moves poorly, the sheet packing 37 and the metal (Loading sleeve) 33
And a gap is generated, and gas containing ash leaks and leaks out of the ceramic tube 31. When a ceramic tube having such a structure is applied to an IGCC dust collector, the dust concentration cannot be reduced, and the gas concentration of 1 mg / Nm ³ or less of the dust concentration required by the IGCC cannot be realized.
Some countermeasures are needed.

Therefore, in the present invention, as a sealing structure of a ceramic pipe applied to an IGCC for performing coal gasification and supplying the gas to a gas turbine, a gap is not formed at a portion where the ceramic pipe and the load sleeve come into contact with each other. In order to prevent the gas from leaking to the outside from this gap, reduce the gas concentration after treatment with a dust collector,
An object of the present invention is to provide a seal structure of a ceramic filter applicable to an integrated coal gasification combined cycle power plant.

[0012]

The present invention provides the following means (1) to (4) in order to solve the above-mentioned problems.

(1) A ceramic tube having a ceramic tube, a sleeve concentrically mounted on an upper end thereof, and a cylindrical seal portion which is vertically movably disposed around the outer periphery of the distal end of the sleeve via a seal member. In the filter, a stepped riding surface is formed around the outer periphery of the sleeve, and a spring is disposed between the riding surface and the lower end of the cylindrical seal portion in a state where an elastic force is applied. Ceramic filter seal structure.

(2) In the invention according to the above (1), a dust intrusion preventing member is provided between the periphery of the distal end of the sleeve and the periphery of the upper end of the seal portion. .

(3) In the invention according to the above (1) or (2), the spring is a single coil spring wound around the outer periphery of the sleeve.

(4) In the invention of the above (1) or (2), the spring comprises a plurality of coil springs having a diameter smaller than the width of the riding surface of the sleeve, and the coil springs are vertically arranged all around the sleeve. A sealing structure for a ceramic filter, wherein the sealing structure is uniformly arranged with an elastic force applied.

In (1) of the present invention, a riding surface is formed on the sleeve, and a spring for applying elastic force is interposed between the riding surface and the lower end of the seal portion which can move up and down. , The force that pushes down the load sleeve from the seal part acts, the lower end of the load sleeve comes into strong contact with the upper end of the ceramic tube,
Even if thermal deformation occurs, the spring force causes the load sleeve to constantly contact the ceramic tube, without creating a gap in this contact portion, preventing gas leakage, improving the sealing performance of the ceramic filter, Dust concentration can be reduced.

In the method (2) of the present invention, since the ceramic bug is provided, the ash in the gas is prevented from entering the gap of the seal portion, and the sliding of the seal portion is improved. The effect of (1) is further ensured.

In (3) of the present invention, there is an advantage that the spring is a single coil spring, the number of parts is reduced and assembly is easy, and in (4), a plurality of small-diameter coil springs are mounted on the entire circumference of the load sleeve. The number of parts increases because of the uniform arrangement of the coil springs.However, if the tube plate on which the ceramic tube is mounted is inclined or the seal moves unevenly around the By the action, the sliding of the seal portion can be made smooth.

[0020]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a sectional view showing a seal structure of a ceramic filter according to a first embodiment of the present invention, which is mainly applied to a dust collector of an IGCC. In FIG. 1, reference numeral 1 denotes a ceramic tube, 2 denotes a self-weight seal, and a weighting sleeve 3 is provided at an upper end thereof.
(Metal tube) is placed. Reference numeral 4 denotes a main body on which a flange 4a is formed. Reference numeral 5 denotes a cylindrical seal portion, which is provided around the distal end of the weight sleeve 3, and a seal member 6 is disposed between the seal member 5 and the weight sleeve 3. The sealing member 6 is a member combining a ceramic fiber material and a metal ring as in the conventional case.

Reference numeral 13 denotes a cylindrical ring, and reference numeral 13a denotes a flange. 14 is a gap between the weight sleeve 3 and the cylindrical ring 13, and 15 is an upper cylindrical member. The flange 13 a and the upper cylindrical member 15 are integrally connected together with the flange 4 a of the main body 4 and the sealing portion 5 by a bolt nut 16.

Reference numeral 20 denotes a coil spring,
Is formed around the weighting sleeve 3 in a state where an elastic force is applied between the stepped riding surface 3a and the flange surface 5a of the seal portion 5. Coil spring 2
Numeral 0 is formed by winding one wire in a coil shape, and acts so as to press the weight sleeve 3 against the seal portion 5 against the self-weight seal.

The reason why the coil spring 20 is provided is that the ceramic filter used in the conventional PFBC has a high gas temperature of about 850 ° C.
Since the gas temperature is as low as about 450 ° C., a coil spring can be adopted.

In the first embodiment of the above construction, a difference in thermal expansion between the weight sleeve 3 and the structure composed of the main body 4, the seal portion 5, the flange 13a and the upper cylindrical member 15 occurred during operation. Can be slid with the weighting sleeve 3 via the seal member 6 and the coil spring 20
Presses the weight sleeve 3 against the self-weight seal 2,
It is possible to prevent gas from leaking out of the ceramic tube 1 from this abutting portion without forming a gap between the ceramic tube 1 and the load sleeve 3.

FIG. 2 is a sectional view of a sealing structure of a ceramic filter according to a second embodiment of the present invention. In the structure of the first embodiment, ash is prevented from entering the gap 14 of the sealing portion. This is a structure with ceramic bugs added. In the figure, reference numeral 10 denotes a ceramic bug, the periphery of which is sandwiched between a flat mounting member 12 and a flange 13a, and is mounted between the upper cylindrical member 15 and the flange 4a of the main body 4 with a bolt and nut 16. Further, the inner periphery thereof is attached to the tapered end portion of the load sleeve 3 by bolts 11 at a plurality of locations in the circumferential direction. Other configurations are the same as those of the first embodiment.

The ceramic bug 10 is a ceramic woven fabric, and the weave is made of twill or satin weave, and is preferably a weave that does not enlarge the texture due to deformation of the fiber due to heat. Further, the ceramic bug 10 may be a woven fabric of metal fiber instead of the fiber of the ceramic material,
When used for IGCC, ceramic fibers are preferred.

In the second embodiment, as in the first embodiment, the coil spring 20 presses the weighting sleeve 3 against the self-weighting sleeve 2, and a gap is formed between the ceramic tube 1 and the weighting sleeve 3. Therefore, gas leakage from the contact portion can be prevented. Furthermore, in addition to this effect, the gap 14 between the weighting sleeve 3 and the cylindrical ring 13 has no opening because the upper part is covered with the ceramic bug 10 over the entire circumference thereof. The ash does not penetrate, and the ash does not accumulate and stick. This makes the movement of the seal portion smooth, and does not hinder absorption of the difference in thermal expansion.

FIG. 3 is a sectional view of a sealing structure of a ceramics filter according to a third embodiment of the present invention, and FIG. 4 is a sectional view taken along the line AA in FIG. In both figures, the part different from the first embodiment of FIG. 1 is that a plurality of small coil springs 21 are used in place of the coil spring 20, and the other configuration is the same as that shown in FIGS.

In FIG. 3, the coil spring 21 is composed of a single coil having a diameter that can be accommodated in the gap 22 between the peripheral surface of the weighting sleeve 3 and the inner side surface of the main body 4. The lower end is locked to the riding surface 3a of the weight sleeve 3 on the flange surface 5a, and the weight sleeve 3 is pressed downward against the seal portion 5 so that no gap is formed in the contact portion with the self-weight seal 2. I have.

FIG. 4A is a sectional view taken along line AA in FIG.
(B) is an enlarged detailed view of a portion B. As shown in (a), the coil spring 21 is attached to the riding surface 3a around the weighting sleeve 3 by eight.
The books are evenly arranged, and each coil spring 21 has an upper end engaged with a locking member 23 provided on the flange surface 5a of the seal portion 5 as shown in FIG. It is arranged in a state where it is engaged with the locking member 24 provided in 3a and biases the elastic force. In addition, this coil spring 2
The number 1 is not limited to eight, but may be eight or more or eight or less, and may be configured so as to be evenly distributed over the entire circumference.

In the example of FIG. 3 described above, an example in which a plurality of coil springs 21 are used instead of the coil spring 20 of the first embodiment without the ceramic bug 10 has been described.
It is needless to say that the present embodiment may be applied in place of the coil spring 20 of the second embodiment to which the ceramic bug 20 is added, and according to the third embodiment, the same as the first and second embodiments. The effect is obtained, and the plurality of coil springs 21 are evenly arranged on the entire circumference, so that the spring force works effectively even when the tube sheet is inclined.

[0032]

The sealing structure of the ceramic filter according to the present invention comprises: (1) a ceramic tube, a sleeve concentrically mounted on the upper end of the ceramic tube, and a vertically movable outer peripheral portion of the sleeve via a sealing member. In a ceramic filter having a cylindrical seal portion disposed, a stepped riding surface is formed around the outer periphery of the sleeve, and an elastic force is urged between the riding surface and the lower end of the cylindrical seal portion. It is characterized in that a spring is arranged in a state. (2) is (1)
In the seal structure according to the invention, a dust intrusion prevention member is disposed between the periphery of the distal end of the sleeve and the periphery of the upper end of the seal portion. With this configuration, a force that pushes down the load sleeve from the seal portion acts, and the lower end of the load sleeve comes into strong contact with the ceramic tube. Can be prevented, and the dust concentration can be reduced.
Further, as in (2), the ash in the gas is prevented from entering the gap of the seal portion due to the ceramic bug, and the sliding of the seal portion is improved, so that the effect of the above (1) is further ensured. .

(3) The present invention relates to the above (1) or (2)
In the invention, the spring is a single coil spring wound around the outer periphery of the sleeve, and in (4), the spring comprises a plurality of coil springs having a diameter smaller than the width of the riding surface of the sleeve. The coil spring is characterized in that the coil spring is uniformly arranged in a state where elastic force is urged up and down over the entire circumference of the sleeve. With such a configuration, the number of components can be reduced by using a single coil spring of (3), and a plurality of small-diameter coil springs are arranged as shown in (4) to prevent movement of the seal portion. The pressing sleeve is pressed uniformly against the ceramic tube to ensure the effect of preventing gas leakage from the contact portion.

[Brief description of the drawings]

FIG. 1 is a sectional view of a ceramic filter sealing structure according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a seal structure of a ceramics filter according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a seal structure of a ceramics filter according to a third embodiment of the present invention.

FIGS. 4A and 4B show details in FIG. 3, wherein FIG. 4A is a sectional view taken along the line AA, and FIG.

FIG. 5 is a general view showing a high-temperature gas dust collector,
FIG. 2A is a configuration diagram illustrating a dust collector main body, and FIG. 2B is a configuration diagram illustrating an internal cassette pack.

FIG. 6 is a longitudinal sectional view of a conventional ceramic tube.

FIG. 7 is a detailed view of a portion C in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic pipe 2 Self-weight seal 3 Weighting sleeve 3a Riding surface 4 Main body 5 Seal part 6 Seal member 10 Ceramic bug 12 Mounting material 13 Cylindrical ring 13a Flange 14 Gap 15 Upper cylindrical member 20, 21 Coil spring 22 Gap 23, 24 Locking member

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shoji Kitada 1-1, Akunoura-cho, Nagasaki-shi Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (72) Inventor Shigetasu Ishigami 1-1, Akunoura-cho, Nagasaki-shi Nagasaki Mitsubishi Heavy Industries, Ltd. Inside the shipyard (72) Inventor Katsuya Ito 1-1 1-1 Akunouramachi, Nagasaki-shi F-term in Nagasaki Shipyard, Mitsubishi Heavy Industries, Ltd. 4D019 BA05 CA03 CB01 CB04 4D058 JA02 JB06 KA01 KA08 KA27 KB05 KC55 KC62 KC63 KC64 KC80 SA20

Claims (4)

[Claims] 1. A ceramic having a ceramic tube, a sleeve concentrically mounted on an upper end thereof, and a cylindrical seal portion slidably disposed vertically around a distal end portion of the sleeve via a seal member. In the filter, a stepped riding surface is formed around the outer periphery of the sleeve, and a spring is disposed between the riding surface and the lower end of the cylindrical seal portion in a state where an elastic force is applied. Ceramic filter seal structure. 2. The ceramic filter sealing structure according to claim 1, wherein a dust intrusion preventing member is disposed between a periphery of a tip portion of the sleeve and a periphery of an upper end portion of the seal portion. 3. The spring according to claim 1, wherein the spring is a single coil spring wound around the outer periphery of the sleeve.
Or the seal structure of the ceramic filter according to 2. 4. The spring comprises a plurality of coil springs each having a diameter smaller than a width of a riding surface of the sleeve, and the coil springs are uniformly arranged in a state where elastic force is applied up and down over the entire circumference of the sleeve. 2. The method according to claim 1, wherein
Or the seal structure of the ceramic filter according to 2.