JP3774555B2 - Smoke exhaust duct and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flue gas duct such as a boiler and a method for manufacturing the same, and more particularly, to a flue gas duct having practically sufficient heat resistance and corrosion resistance to induce high temperature and corrosive flue gas from a boiler and a method for manufacturing the same. .
[0002]
[Prior art]
The conventional smoke exhaust duct has a structure in which a thin plate made of carbon steel is reinforced with ribs, the inner surface in contact with the smoke exhaust is subjected to a flaring treatment, and the outer surface is provided with a layer made of a foam for heat insulation. .
[0003]
[Problems to be solved by the invention]
The flue gas duct with the above structure needs to be periodically repaired because it causes carbon steel corrosion in the long term. In addition, a flue gas duct used for a large boiler such as a power plant has a cross-sectional size of several meters. The conventional structure in which a thin plate is reinforced with ribs on such a large duct generates chatter vibrations due to wind load, and thus it is necessary to reinforce it more than necessary. For this reason, the weight tends to be large and the foundation structure supporting the duct tends to be large. The flue gas from boilers and the like contains a large amount of water vapor, sulfide (SOx), nitride (NOx), active ions, and the like, so that if the flue gas is condensed on the duct wall, it corrode violently. In order to prevent this dew condensation, it is necessary to keep the duct wall at the same temperature as the flue gas, and it is necessary to cover the outer periphery of the duct with a foam having the required thickness. It was hanging.
[0004]
It is an object of the present invention to provide a flue gas duct excellent in corrosiveness at high temperature and chatter vibration due to wind load and mechanical strength, and a method for producing the same.
[0005]
[Means for Solving the Problems]
The gist of the present invention is a sandwich plate comprising a core material made of foam and a face material laminated on both sides of the core material and made of fiber-reinforced plastic so that the face materials are inside and outside the smoke exhaust duct. It is in the smoke exhaust duct assembled.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
1 and 4 are views showing examples of the smoke exhaust duct of the present invention, and FIG. 1 shows a state during assembly of the smoke exhaust duct. As shown in FIGS. 1 and 4, the smoke exhaust duct of the present invention includes a core material made of a foam 5 and face materials 4 and 4 made of fiber-reinforced plastic and laminated on both surfaces of the core material. The smoke exhaust duct is formed by assembling the sandwich plates 8a and 8b so that the face members 4 and 4 are inside and outside the exhaust duct.
[0007]
The core material constituting the sandwich plate is made of a material having heat resistance, high temperature corrosion resistance, and excellent heat retention. If a material containing air and having a specific gravity of about 0.01 to 0.3, preferably 0.02 to 0.05 is used as the core material, a smoke exhaust duct excellent in heat retention can be obtained. A material suitable as a core material is a foam of a thermosetting resin having the specific gravity. Examples of the thermosetting resin include phenol resin, vinyl ester resin, unsaturated polyester resin, and the like. If a phenol resin foam is used for the core material, it is easy to obtain practical durability, flame retardancy, and heat retention in a high temperature corrosive atmosphere necessary for the smoke exhaust duct, and heat for forming the face material 4 It can be easily bonded to the face material 4 by a curable resin.
[0008]
The face material 4 laminated on both surfaces of the core material is made of fiber reinforced plastic. The fiber reinforced plastic is obtained by reinforcing a resin that is a matrix using reinforcing fibers such as carbon fibers, glass fibers, and aramid fibers. When the above-mentioned thermosetting resin is used as the matrix resin, a high-temperature and corrosion-resistant smoke exhaust duct can be obtained. Phenol resin is preferred as the matrix resin.
[0009]
The sandwich plate can be produced by forming layers in which reinforcing fibers are impregnated with a thermosetting resin such as a phenol resin solution on both surfaces of a core material, and then curing the resin.
[0010]
The layer made of fiber reinforced plastic constituting the face material 4 may be a single layer, but is preferably a composite layer in which two or more layers are formed. As shown in FIGS. 3 and 6, a preferred structure of the sandwich plate is that a carbon fiber reinforced plastic layer 3 reinforced with carbon fiber is formed on a glass fiber reinforced plastic layer 1 reinforced with glass fiber, A composite layer in which the glass fiber reinforced plastic layer 1 is formed on the carbon fiber reinforced plastic layer 3 is provided as a face material 4 on one side, and the foam 5 layer is formed on the face material 4 as a core material. The glass fiber reinforced plastic layer 1 is formed on the foam 5 layer, and the carbon fiber reinforced plastic layer 3 is formed on the glass fiber reinforced plastic layer 1. A composite layer having a glass fiber reinforced plastic layer 1 formed thereon is provided as a face material 4 on the other surface, and these layers are integrated by a resin. Thus, if the glass fiber reinforced plastic layer 1 is laminated | stacked on both surfaces of the carbon fiber reinforced plastic layer 3, the smoke exhaust duct excellent in specific strength or the adhesiveness of a surface material and a core material will be obtained.
[0011]
The sandwich plates are connected to each other in the longitudinal direction so that the face materials 4 and 4 are inside and outside the smoke exhaust duct, thereby forming a smoke exhaust duct. The smoke exhaust duct uses a sandwich plate having a core material made of foam 5 and face materials 4, 4 laminated on both sides of the core material and made of fiber reinforced plastic. Practical strength and heat retention performance against negative pressure at times.
[0012]
As shown in FIGS. 1 and 4, an example of a method for continuously sandwiching sandwich plates is to place a glass fiber fabric impregnated with a thermosetting resin so as to cover at least the inner surface of the connection part of the smoke exhaust duct. Subsequently, the thermosetting resin is cured to form an overlay portion 15 made of fiber reinforced plastic, and the sandwich plates are connected to each other. That is, a glass fiber cloth impregnated with a thermosetting resin is attached to the inside of the smoke exhaust duct, or a thermosetting resin is impregnated from above the glass fiber cloth placed inside the smoke exhaust duct, and then the thermosetting resin. The overlay portion 15 is formed by curing, and the sandwich plates are bonded to each other by the overlay portion 15 and the joint is sealed. As shown in FIGS. 1 and 4, the overlay portion 15 may be provided around the connecting portion of the sandwich plate, or may be provided not only around the connecting portion but also on the entire inner surface of the smoke exhaust duct.
[0013]
As shown in FIGS. 1 and 3, if a sandwich plate 8 a in which the flange 7 that can be abutted is formed integrally with the face material 4 is used, the assembly of the smoke exhaust duct is easy.
As the flange, a flange protruding outside the face material is preferable, and the flange is preferably made of fiber reinforced plastic.
When the smoke exhaust duct is assembled, the flanges 7 and 7 are butted together, and the butted portion is fixed using a corrosion-resistant bolt such as fiber reinforced plastic or stainless steel bolt, and the sandwich plate 8a is made continuous. In addition, since the flange 7 has a reinforcing effect, the deformation of the smoke exhaust duct is prevented.
[0014]
In order to obtain a smoke exhaust duct having a greater strength against wind pressure and negative pressure during operation, it is preferable to further reinforce the smoke exhaust duct. An example of the reinforced smoke exhaust duct is a smoke exhaust duct in which the brace material 14 is fixed to the overlay portion 15 via the bracket 13 as shown in FIG. For such reinforcement, the bracket 13 is disposed inside the smoke exhaust duct, the glass fiber fabric impregnated with the thermosetting resin is disposed on the inner surface of the smoke exhaust duct, and then the thermosetting resin is cured to overlay. This is achieved by fixing the bracket 13 with the overlay portion 15.
The bracket 13 is a member having a diameter larger than that of the brace material 14 provided at the distal end portion of the brace material 14 that acts as a fascia that supports the wall of the smoke exhaust duct from the inside. When the bracket 13 and the brace material 14 are made of fiber reinforced plastic, the corrosion resistance is excellent or the specific rigidity is excellent.
As shown in FIG. 2, the reinforcement is made by placing a bracket 13 inside the smoke exhaust duct and attaching a glass fiber fabric impregnated with a thermosetting resin around the bracket 13 or placing it around the bracket 13. The glass fiber fabric is easily impregnated with a thermosetting resin, and then the thermosetting resin is cured, and the bracket 13 is adhered and fixed to the inner surface of the smoke exhaust duct simultaneously with the curing of the thermosetting resin. . Examples of the glass fiber fabric include reinforcing fiber cloth or mat such as glass roving cloth and glass chopped mat.
[0015]
As another example of reinforcement, as shown in FIGS. 4 and 6, a sandwich plate in which a layer having rigidity, that is, a modulus of elasticity larger than that of the foam 5 is provided as a rib 6 between the foam 5 and the foam 5. The method using 8b is mentioned. The ribs 6 are for preventing the deformation of the foam 5 and can be provided between the face plate 4 and the face plate 4 in a lattice shape or a honeycomb shape. The ribs 6 are preferably made of fiber reinforced plastic, and such ribs 6 can be formed by covering the plate thickness surface (side surface) of the block of the foam 5 with a layer of fiber reinforced plastic.
[0016]
Examples of embodiments of the present invention are shown below.
Example 1
The smoke exhaust duct of the present embodiment is obtained by assembling the sandwich plate 8a shown in FIG. As shown in FIG. 1, the flue gas duct has a sandwich plate 8a provided with a core material made of foam 5 and face materials 4, 4 made of fiber reinforced plastic and laminated on both surfaces of the core material. The smoke exhaust duct is assembled so that the materials 4 and 4 constitute the inner surface and the outer surface of the smoke exhaust duct, and a plate-like flange 7 standing at the upper end of the face material 4 is integrated with the face material 4. The sandwich plate 8a formed in the above is a flue gas duct which is fixed to the flange 7 and the flange 7 in abutment and is continuous in the longitudinal direction. The sandwich plate 8a is made of fiber reinforced plastic from the inside of the flue gas duct. As shown in FIG. 2, the brace material 14 that supports the wall of the smoke exhaust duct from the inside is fixed to the overlay portion 15 via the bracket 13 as shown in FIG. It is.
[0017]
Example 2
FIG. 4 shows the smoke exhaust duct of this embodiment. The flue gas duct is obtained by assembling the sandwich plate 8b shown in FIG. As shown in FIG. 4, the flue gas duct has a sandwich plate 8b provided with a core material made of foam 5 and face materials 4, 4 made of fiber reinforced plastic and laminated on both surfaces of the core material. The smoke exhaust duct is assembled so that the materials 4 and 4 are inside and outside the smoke exhaust duct, and the sandwich plates 8b and 8b are bonded and fixed from the inside of the smoke exhaust duct by the overlay portion 15 made of fiber reinforced plastic. Furthermore, a rib 6 made of a material having a rigidity higher than that of the foam 5 is formed between the block of the foam 5 and the block of the foam 5 to prevent the foam 5 from being bent. is there.
In addition, the flue duct of the present embodiment may be provided with a flange as in the first embodiment, or may be further reinforced by providing a brace material 14 and a bracket 13 as shown in FIG. Both may be provided.
[0018]
【Example】
Hereinafter, the present invention will be described with reference to examples.
Example 1
The smoke exhaust duct shown in FIG. 1 was manufactured as follows.
Carbon fiber cloth, glass fiber mat [trade name Pyrofil (registered trademark) TRK910 mat, manufactured by Mitsubishi Rayon Co., Ltd.] and glass fiber chopped strand mat (# 500) were prepared as reinforcing fibers. As the resin, a phenol resin for hand lay-up [manufactured by Showa Polymer Co., Ltd., trade name Shonor (registered trademark) BRL-240] was prepared. As the foam, a phenol resin foam (specific gravity was about 0.04 and thickness 100 mm) in which phenol resin was foamed 30 times was prepared.
[0019]
The glass fiber mat (abbreviated as M), carbon fiber cloth (abbreviated as C), glass fiber mat, phenol resin foam (abbreviated as F), glass fiber mat, carbon fiber cloth, and glass fiber mat in this order. The laminate was placed on a surface plate subjected to mold release treatment, and the mat and cloth were impregnated with the above-mentioned phenol resin to obtain a laminate having a structure of M / C / M / F / M / C / M. Further, in order to form the flange 7 on the uppermost layer (layer in which the glass fiber mat is impregnated with the phenol resin), the glass fiber mat is stacked to a thickness of about 20 mm. Was impregnated with a phenolic resin.
[0020]
This laminate is heated in an oven at 80 ° C. for 1 hour to cure the phenolic resin impregnated in the mat and cloth, and remove the laminate from the surface plate. As shown in FIG. With respect to the longitudinal direction, a sandwich plate 8a was obtained in which the distance between the flange portions was 300 mm) integrated on one side.
[0021]
After processing the sandwich plate 8a to a predetermined size, etc., and transporting it to the site, the sandwich plate 8a is connected to form a duct, a reinforcing brace material 14 and a bracket 13 are disposed in the duct, and a phenolic resin is placed on the glass roving cloth. 1 is attached to the inside of the connecting portion of the sandwich plate 8a and around the bracket 13, and the phenol resin is cured at room temperature to form the overlay portion 15, thereby assembling the smoke exhaust duct shown in FIG. .
The brace material 14 was obtained by winding an interdigital cloth with the fibers oriented in the axial direction around a pipe reinforced with an unsaturated polyester resin with a glass fiber mat and molding it by hand layup. As the bracket 13, a pipe formed by reinforcing an unsaturated polyester resin with a glass fiber mat and a glass fiber cloth was used. After the pipe was attached to the corner inside the duct by the overlay portion 15, the brace material 14 was inserted when the sandwich plate 8a was assembled.
[0022]
Example 2
The smoke exhaust duct shown in FIG. 4 was manufactured as follows.
As the reinforcing fiber and resin, the same carbon fiber cloth, glass fiber mat, glass fiber chopped strand mat and phenol resin as in Example 1 were prepared. The same block of phenol resin foam as in Example 1 (length, width 500 mm, thickness 100 mm) was prepared as a foam.
In the same manner as in Example 1, a glass fiber mat, a carbon fiber cloth, and a glass fiber mat were placed on a surface plate in this order, and these mats and cloth were impregnated with a phenol resin, and M / C / It was set as the laminated body of the structure of M. The phenolic resin foam block was placed on the laminate.
[0023]
When a phenol resin foam is placed on a laminate of M / C / M structure, the chopped strand mat of glass fiber is placed on the plate thickness surface (side surface) of the block of foam 5 as shown in FIG. One ply was wound, and a plurality of blocks of phenol resin foam 5 were arranged on the laminate while being abutted against each other while forming an impregnated layer 6 ′ sufficiently impregnated with phenol resin on the wound chopped strand mat. The impregnated layer 6 ′ is for forming the rib 6.
[0024]
Next, a glass fiber mat, a carbon fiber cloth, and a glass fiber mat are further placed in this order on the phenol resin foam 5 and the impregnation layer 6 ′ in the same manner as in Example 1, and the laminate is impregnated with the phenol resin. Got.
[0025]
This laminate was heated and cured in the same manner as in Example 1 to obtain a sandwich plate 8b of FIG. 6 having ribs 6 in a lattice shape between the foams 5 and 5.
[0026]
By forming the overlay portion 15 using a glass chopped mat impregnated with a phenol resin, the sandwich plate 8b was assembled to obtain a smoke exhaust duct having the structure shown in FIG.
[0027]
【The invention's effect】
As described above, the smoke exhaust duct of the present invention has a wall structure having practical strength and heat retention performance against wind pressure and negative pressure during operation. Therefore, the heat insulation work is omitted, and it is excellent in corrosion resistance and does not need to be repaired semipermanently, so that labor saving can be achieved, and chatter vibration due to wind is also eliminated because of high rigidity over the entire surface. Furthermore, compared to the conventional duct structure in which a thin plate made of carbon steel or stainless steel is reinforced with ribs, the weight is about 1/5, so that heavy equipment for installation work can be omitted, and the basic structure is greatly reduced. Simplification is possible. The flue gas duct of the present invention is useful as a flue gas duct between a boiler of a power plant and a desulfurizer, and can produce a large flue gas duct having a cross-sectional dimension of 10 m × 10 m and a length of 300 m, for example. According to the method for manufacturing a smoke exhaust duct of the present invention, it is easy to manufacture such a smoke exhaust duct.
[Brief description of the drawings]
FIG. 1 is a schematic view illustrating an example of a smoke exhaust duct according to the present invention.
FIG. 2 is a view showing an example of a reinforcing structure of a smoke exhaust duct using a bracket and a brace material.
FIG. 3 is a cross-sectional view showing an example of a sandwich plate.
FIG. 4 is a schematic view illustrating another example of the smoke exhaust duct of the present invention.
FIG. 5 is a perspective view for explaining an example of a manufacturing method of a sandwich plate provided with ribs.
FIG. 6 is a cross-sectional view illustrating an example of a sandwich plate provided with ribs.
[Explanation of symbols]
1 .... Glass fiber reinforced plastic layer, 3 .... Carbon fiber reinforced plastic layer, 4 .... Face material, 5 .... Foam, 6 .... Rib, 6 '... Impregnation layer, 7 .... Flange, 8a, 8b ..Sandwich plate, 13 ... Bracket, 14 ... Brace material, 15 ... Overlay part

Claims (6)

Smoke exhaust assembling a sandwich plate comprising a core material made of foam and a face material laminated on both sides of the core material and made of fiber reinforced plastic so that the face material is inside and outside the smoke exhaust duct A duct ,
The sandwich plates are bonded by an overlay portion made of fiber reinforced plastic from the inside of the smoke exhaust duct,
A smoke exhaust duct in which a brace material made of fiber reinforced plastic is fixed to the overlay portion via a bracket .   2. The smoke exhaust duct according to claim 1, wherein a sandwich plate in which a flange is formed on the face material is assembled.   The smoke exhaust duct according to claim 1, wherein a sandwich plate in which a rib having a rigidity higher than that of the foam is formed between the foam and the foam is assembled.   The smoke exhaust duct according to claim 1, wherein a sandwich plate in which flanges are integrally formed is continuous in a longitudinal direction by fixing the flanges together.   Assembling a sandwich plate having a core material made of foam and a face material made of fiber-reinforced plastic laminated on both sides of the core material so that the face material is inside and outside the smoke exhaust duct, A method for producing a smoke exhaust duct, in which a glass fiber fabric impregnated with a thermosetting resin is disposed on the surface, and then the thermosetting resin is cured to form an overlay portion. The method for manufacturing a smoke exhaust duct according to claim 5 , wherein a bracket is disposed inside the smoke exhaust duct, and the bracket is fixed at an overlay portion.

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