JP3294016B2 - High temperature dust filter holding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for holding a filter in a high-temperature dust remover used in a pressurized fluidized-bed boiler or the like.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional high-temperature dust remover. This dust remover has a gas inlet 1 at a lower portion and a gas outlet 3 at an upper portion, and has a cylindrical dust remover made of a porous solid such as porous ceramics having an upper end closed and an open lower end. The dust filter 2 is arranged in the up-down direction. The dust remover includes a cylindrical body 5 and a top plate 7 for closing the upper part of the body 5.
An inverted conical hopper 6 is provided below the body 5, and a dust discharge port 4 is provided at a lower end of the hopper 6.

[0003] A refractory heat insulating material 8 is lined on the inner surface of the dust remover. The lower end of the dust removal filter 2 is
, And is supported at one end so as to be free from stress caused by elongation in the length (axial) direction of the dust removal filter 2 under high temperature.

In this dust remover, high-temperature gas containing dust entering the dust remover from the gas inlet 1 enters the dust remover filter 2 from the lower portion of the dust remover filter 2 and from the inner surface to the outer surface of the filter 2. When flowing toward the filter, the gas is filtered, and clean gas flows from the outer surface of the dust filter 2. This clean gas is sent from the gas outlet 3 to the outside of the dust remover.

On the other hand, dust adhering to the inner surface of the dust filter 2 becomes detached and falls when the thickness exceeds a certain thickness, and is stored in a dust hopper (not shown) via a dust outlet 4. In order to promote the separation of the dust, backwashing in which a pulsed air flow or the like flows from the outer surface to the inner surface of the dust filter 2 may be performed.

[0006]

In the above-described conventional high-temperature dust remover, the stress generated by the elongation of the dust filter at a high temperature in the length direction is released.
Since the dust filter is supported at one end, there are the following problems.

[0007] (1) When a dust filter is subjected to a lateral vibration, for example, an earthquake, all the bending stress is received at one support portion at the lower end, and the filter is damaged.

(2) Even if the vibration is weak in the lateral direction (for example, when the device in which the dust remover is installed is operating constantly), a large bending moment is generated in the support portion. . Therefore, the length per dust filter cannot be increased.

The present invention relates to a high-temperature dust filter configured to prevent breakage due to vibration of the dust filter in a high-temperature dust filter and to effectively prevent stress from being generated in the dust filter due to a temperature change. It is an object to provide a holding device.

[0010]

SUMMARY OF THE INVENTION In the present invention, a high temperature dust filter made of a brittle material such as ceramics is used to reduce the occurrence of bending and at the same time to keep the internal stress of the filter caused by thermal elongation low. The following measures were adopted. That is, in the holding device for the high temperature dust filter according to the present invention, one end of the dust filter is held by the first member fixed to the body of the dust filter, and the other end of the dust filter is used for adjusting the expansion. The filter is held by a second member having a medium injection section and capable of absorbing the thermal expansion of the dust filter, and the thermal expansion of the dust filter in a high-temperature atmosphere causes a stress greater than the allowable stress of the dust filter inside the dust filter. Adjustable so that there is no.

In the holding device of the present invention, the first end piece may be arranged at the upper end of the dust filter, and the second member having the medium injection section may be arranged at the lower end of the dust filter. The medium injection section may have a structure in which a heating / cooling medium inlet and a heating / cooling medium outlet for flowing the heating / cooling medium are provided.

[0012]

In the holding device for a high-temperature dust filter according to the present invention, one end of the dust filter is held by the first member fixed to the body of the dust filter, and the other end of the dust filter is expanded and adjusted. In the case of a thermally stable state and a thermally instable state, it is configured to have a medium injecting section for holding and holding by a second member capable of absorbing the thermal expansion of the dust filter, The generation of stress due to the difference in the amount of thermal expansion between the dust removal filter and the member holding the filter can be prevented as follows.

(1) At least the first member of the members holding the dust filter is kept at the same temperature as the ambient temperature of the dust filter in a thermally stable state. Under this condition, the relative displacement of the portion connecting the second member and the dust filter becomes zero (or the amount by which the stress becomes less than an allowable value) with respect to the end face of the dust filter to be connected. The structure prevents generation of stress due to a difference in thermal expansion between the dust removal filter and a member holding the filter.

(2) Under a condition that is not thermally stable, the second member can be heated or cooled by injecting a heat medium into the expansion adjusting medium injection section, and the second member can be heated or cooled. Adjust the amount of elongation according to the elongation of the dust filter,
The stress generated in the dust removal filter is suppressed to an allowable value or less.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a holding device for a high-temperature dust filter according to the present invention will be described in detail with reference to an embodiment shown in FIG. In FIG. 1, the same components as those of the conventional dust remover shown in FIG. 2 are denoted by the same reference numerals, and redundant description thereof will be omitted.

The dust remover shown in FIG. 1 is similar to the conventional dust remover shown in FIG.
The fireproof heat insulating material 8 is lined on the inner surfaces of the body portion 5 and the hopper portion 6. The purpose of this is torso 5
This is to protect the material of the hopper portion 6 and at the same time keep the temperature of both members low (about 100 ° C. or less) and minimize the dimensional change in the longitudinal direction due to the temperature.

A support end 9 and 10 made of a heat-resistant material (generally stainless steel) are fixed to the body 5 by welding or the like, and a cap 11 is attached to the first support end 9. The sealing members 12a and 12b simultaneously seal the gas and hold the upper part of the dust filter 2 at the same time.

The other second support end 10 has a medium injection section 10a having a double cylindrical structure extending downward and fixing the lower portion of the dust filter 2 at the end of the double cylindrical structure. ing. The fixing part is a ceramic adhesive 13
Is filled. 1. In FIG. 1, the other components are shown in FIG.
This is the same as the conventional dust remover shown in FIG.

In the dust remover shown in FIG. 1, gas containing dust enters the dust remover from the gas inlet 1 and is filtered from the lower part of the dust filter 2 when passing through the inner surface of the dust filter 2. Only the clean gas flows from the outer surface of the dust filter 2. The filtered gas is sent from the gas outlet 3 to the outside of the dust remover.

On the other hand, the dust adhering to the inner surface of the dust filter 2 is peeled off when it has a certain thickness or more, falls, and accumulates in a dust hopper (not shown) via the dust discharge port 4. In addition, backwashing may be performed with pulsed air or the like to promote peeling.

Next, the specific structure and function of the medium injection section 10a in the filter holding device of the dust remover of FIG. 1 will be described. The length of the medium injection section 10a is determined from the coefficient of linear expansion of the material forming the dust filter 2 and the material forming the support end 10.

A specific example will be described below. In addition, this example is a case where it is thermally stable.

(I) Coefficient of linear expansion of filter α ₁ = 4 × 1
0 ^-6 / ° C (certain ceramics), (II) Coefficient of linear expansion of the second support end α ₂ = 2 × 10 ^-5 / ° C
(III) Atmospheric temperature T ₂ = 850 ° C. (IV) Initial temperature T ₁ = 20 ° C. (V) Length of one filter L ₁ = 2000 mm.

When thermally stable, the elongation ΔL of the dust filter at 850 ° C. is ΔL = (T ₂ −T ₁ ) · L ₁ · α ₁ (mm) (1) Equation = (850-20) ( 2000) (4 × 10 ⁻⁶ ) = 6.64 mm, that is, it extends downward by 6.64 mm. Therefore, if the medium injection section 10 a of the support end 10 extends downward, it is supported by the dust filter 2. The relative displacement due to the thermal expansion of the end 10 becomes zero, and the axial stress (compression or tension) applied to the dust filter 2 can also be made zero.
Medium length L ₂ required for injection compartment 10a deforms the expression (1) _{L 2 = ΔL / (T 2} -T 1) α 2 = 6.64 / (850-20) (2 × 10 -5 ) = 400 mm.

Next, consider the case where the thermal stability is not obtained.
The following two are considered as the unstable state.

(1) The case where the apparatus is used from a cold state and the gas temperatures at the inlet and the outlet of the deduster are significantly different. In this case, in the structure of the present embodiment, since the temperature of the support end 10 and the medium injection section 10a is increased first, the amount of extension of the support end 10 is greater than the amount of extension of the dust filter 2, and the dust filter 2 generates tensile stress. If it becomes necessary to reduce this stress, the medium injection section 10
A cooling fluid is introduced from the heating / cooling medium inlet 15a to lower the temperature of the medium injection section 10a to reduce the amount of elongation, thereby reducing the stress generated in the dust removal filter 2.

(2) When changing the device from a high load to a low load. This is the case where the load on the device to which the high-temperature dust remover is attached is reduced, and the temperature of the gas at the inlet of the high-temperature dust remover is reduced. In this case, contrary to the previous example, the amount of elongation of the dust filter 2 becomes larger than the amount of elongation of the support end 10, so that a compressive stress is generated in the dust filter 2. In order to reduce this stress, a heating fluid is supplied from the heating / cooling medium inlet 15 of the medium injection section 10a to raise the temperature of the medium injection section 10a and increase the temperature of the support end 1a.
Extend 0. In this way, the dust filter is adjusted so as not to generate a stress greater than the allowable stress.

[0028]

As described above, in the holding device for a high-temperature dust filter according to the present invention, one end of the dust filter is held by the first member fixed to the body of the dust filter, and the other end of the dust filter is removed. Since the end portion is held by the second member, the dust filter does not generate a large bending stress in the supporting portion of the dust filter even when it is subjected to vibration from the lateral direction.

Further, since the second member has a medium injection section for adjusting expansion, a heating / cooling medium is flowed through the second member to adjust the temperature of the second member, and the dust filter and the second filter are separated. The difference in thermal expansion between the two members can be suppressed to an allowable range. As described above, according to the present invention, it is possible to use a ceramic dust removal filter with low reliability in a conventional device with high reliability.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of a dust remover according to one embodiment of the present invention.

FIG. 2 is a sectional view showing the structure of a conventional dust remover.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas inlet 2 Dust filter 3 Gas outlet 4 Dust discharge port 5 Body part 6 Hopper part 7 Top plate 8 Fireproof heat insulating material 9 First support end 10 Second support end 10a Medium injection section 11 Cap 12a, 12b Seal material 13 Ceramic adhesive 15 Heating / cooling medium inlet 16 Heating / cooling medium outlet

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-304425 (JP, A) JP-A-59-225721 (JP, A) JP-A-6-15130 (JP, A) JP-A-6-130130 134238 (JP, A) JP-A-6-319928 (JP, A) JP-A-7-68106 (JP, A) JP-A-6-185337 (JP, A) JP-A-1-170420 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 46/24

Claims (1)

(57) [Claims] An apparatus for holding a dust filter in a high temperature dust filter, wherein one end of the dust filter is held by a first member fixed to a body of the dust filter, and the other end of the dust filter is provided. The dust filter is held by a second member having a medium injection section for adjusting expansion and capable of absorbing the thermal expansion of the dust filter, and the dust is removed inside the dust filter by the thermal expansion of the dust filter in a high-temperature atmosphere. An apparatus for holding a high-temperature dust filter, characterized in that the filter is adjustable so as not to generate a stress exceeding the allowable stress of the dust filter.