JP2005155970A - Fiber-reinforced plastic lining pipe for chimney - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber-reinforced plastic lining pipe for a chimney, which is light in weight, has excellent mechanical strength, excellent corrosion resistance and heat resistance, and can be used over a long period. <P>SOLUTION: A fiber-reinforced plastic lining pipe 1 for a chimney, having (a) a base body layer comprising a first fiber-reinforced member containing fibers at least substantially arranged in the circumferential direction and a phenol resin; and (b) a corrosion-resistant layer which is provided on the side of the inner face of the base body layer and contacts with smoke, the layer comprising a second fiber-reinforced member and a phenol resin, and the layer having a larger volumetric compounding ratio of the phenol resin to be incorporated, which is calculated by the formula: volume of the phenol resin/(volume of the reinforced fibers + volume of the phenol resin), than the volumetric compounding ratio in the base body layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lining pipe that can be easily attached to an existing chimney and prevents corrosion of the chimney.

  By strengthening the dioxin method in December 2002, (1) taking a residence time of 2 seconds or more at a combustion temperature of 800 ° C. to 850 ° C. for a waste treatment facility, (2) Three items were obliged to cool the exhaust gas temperature to 200 ° C. or less in order to suppress resynthesis, and (3) to install a bag filter in the exhaust gas treatment section.

  Many chimneys of existing waste (garbage) incinerators have a structure having an outer structure made of reinforced concrete and an inner cylinder made of steel. Before the dioxin method was intensified, corrosion of the steel chimney inner cylinder was not a problem because high-temperature exhaust gas could be discharged. However, after the regulations were strengthened, the exhaust gas temperature had to be lowered to 200 ° C. or lower, substantially 180 ° C. or lower, so that metal corrosion due to condensation of acidic gases such as sulfuric acid and hydrochloric acid progressed, and rust was developed. Occurrence of rust and scattering of rust around the area are problematic. As the material of the steel chimney inner cylinder, acid-resistant metal such as SUS316L is used, but rust generation due to low-temperature corrosion is still an unavoidable problem.

  Therefore, it is conceivable to install a new chimney, but the replacement work requires cost and a long period of time, and it is not realistic to replace only the chimney unless a new incineration facility is installed.

  Therefore, under the present circumstances, corrosion of existing chimneys is prevented by repeatedly applying acid-resistant paint. However, since the durability of the paint is low, it must be applied about once every several months. There wasn't.

  As countermeasures against corrosion of concrete material or iron, JP-A-57-204718 (Patent Document 1) describes a lining system (however, there is no specific description of materials etc.) and fiber reinforcement in an existing chimney. There is a method of inserting a cylinder made of plastic (hereinafter also referred to as FRP as appropriate), and in particular, a method of inserting a cylinder made of FRP is proposed as being excellent. In the invention of this publication, there is a feature in the joining of the FRP tubular unit, and the unit is stacked and joined by inserting the lower end part of the tubular unit into the upper end part having the double tubular receiving part, and the chimney inner cylinder is joined. To form. However, in this publication, there is no description of the material of fiber reinforced plastic, and since a temperature of about 60 to 70 ° C. is assumed, for example, what kind of case is exposed to a temperature of about 150 ° C. to 180 ° C. There is no suggestion as to whether the material and composition should be adopted.

On the other hand, regarding the manufacture of the chimney itself with fiber reinforced plastic (FRP), the claims of Japanese Patent Application Laid-Open No. Sho 62-103138 (Patent Document 2) include a chimney with a corrosion-resistant layer on the smoke contact side and an outer side thereof. It is formed of FRP with a two-layer structure with a reinforcing layer, its corrosion-resistant layer is formed of a thermosetting phenolic resin combined with at least one of a surface mat, cloth or mat, and the reinforcing layer is at least one of cloth or mat It is described that it is formed of a room temperature curable thermosetting resin combined with the above. In the embodiment, glass mat and vinyl ester resin fiber reinforced plastic are used for the reinforcing layer. However, this structure is insufficient in terms of corrosion resistance, heat resistance and mechanical strength.
JP-A-57-204718 JP 62-103138 A

  An object of the present invention is to provide a fiber reinforced plastic lining pipe for a chimney that is lightweight, excellent in mechanical strength, excellent in corrosion resistance and heat resistance, and can be used for a long period of time.

  It is another object of the present invention to provide a permanent repair method using such a lining pipe in repairing a chimney.

  A further object of the present invention is to provide a chimney which is provided with the above-mentioned fiber-reinforced plastic lining pipe and has excellent corrosion resistance and heat resistance and can be used for a long time.

  The present invention relates to the following matters.

  1. A lining pipe for a chimney, comprising: (a) a first reinforcing fiber member containing fibers arranged at least substantially in the circumferential direction; and a base layer made of phenol resin; and (b) provided on the inner surface side of the base layer. It is a layer that comes into contact with smoke, and is composed of a second reinforcing fiber member and a phenol resin, and the volume ratio of the phenol resin calculated by the volume of the phenol resin / (volume of the reinforcing fiber + volume of the phenol resin) is: A fiber-reinforced plastic lining pipe having a corrosion-resistant layer larger than a volume ratio in a base layer.

  2. The lining pipe according to 1 above, wherein the first reinforcing fiber member in the base layer contains fibers in at least two directions of fibers arranged substantially in the circumferential direction and fibers arranged substantially in the axial direction.

  3. The lining pipe according to 1 or 2, wherein the first reinforcing fiber member in the base layer is a woven fabric or a unidirectional fiber material.

  4). The volume ratio of phenol resin calculated by the volume of phenol resin in the base layer / (volume of reinforcing fiber + volume of phenol resin) is represented by Ra, and the volume of phenol resin in the corrosion-resistant layer / (volume of reinforcing fiber). The lining pipe according to any one of the above 1 to 3, wherein Rb is 0.1 or more larger than Ra when the volume blending ratio calculated by + volume of phenol resin is represented by Rb.

  5). The lining pipe according to any one of 1 to 4, wherein the second reinforcing fiber member in the corrosion-resistant layer is a nonwoven fabric.

  6). 6. The lining pipe according to 5 above, wherein the second reinforcing fiber member in the corrosion-resistant layer is a nonwoven fabric made of short fibers.

  7). The process of lowering the lining pipe according to any one of the above items 1 to 6 provided with an attachment to the chimney from the upper part of the chimney and connecting the holding pipe attached to the inside of the chimney is repeated, and the lining pipe is stacked inside the chimney. A chimney repair method characterized by this.

  8). 8. The chimney repair method according to claim 7, wherein a space between the inner wall of the chimney and the lining pipe is set to 50 mm to 500 mm.

  9. A chimney in which the lining pipe according to any one of 1 to 6 is stacked inside the chimney.

  10. 10. The chimney according to 9 above, wherein a space between the inner wall of the chimney and the lining pipe is 50 mm to 500 mm.

  The lining pipe of the present invention comprises at least two layers of a base layer and a corrosion-resistant layer, both of which are made of a fiber reinforced plastic containing a phenol resin and a reinforced fiber.

  Since the lining pipe requires mechanical strength, such as being lifted and attached by a crane or the like at the time of construction, strength and rigidity are required as a whole. Therefore, the base layer uses a fiber containing directional fibers as reinforcing fibers to ensure strength and rigidity while being lightweight. However, it is not sufficient in terms of durability such as corrosion resistance and heat resistance to have the same configuration on the inner surface of the pipe that is in direct contact with the smoke. Therefore, in the present invention, the durability is improved by making the content ratio of the phenol resin in the corrosion-resistant layer that is the pipe inner surface side layer in contact with the smoke higher than the content ratio of the phenol resin in the base layer. In that case, the crack etc. which may generate | occur | produce in a corrosion-resistant layer are effectively prevented by the reinforcement effect of a base layer.

  Therefore, according to the present invention, it is possible to satisfy both the original characteristics of the fiber reinforced plastic, which is lightweight and has high mechanical strength, and the characteristics required for the chimney such as corrosion resistance, heat resistance and durability in a balanced manner. Therefore, permanent chimney repair becomes possible by using the lining pipe of the present invention.

  Moreover, according to the construction method of the present invention, the construction period is significantly shortened compared to the replacement of the chimney, and the durability is much higher than the construction method of painting with acid-resistant paint.

  The fiber reinforced plastic constituting the lining pipe of the present invention is a cured fiber containing reinforcing fiber and a phenol resin, but in the following description, the term “resin” refers to a fluid state before curing and cured. Both are used to mean later. The implications are clear from the context.

<Structure of base layer>
The base layer is a fiber-reinforced plastic layer made of a first reinforcing fiber member and a phenol resin, and is a layer that mainly ensures the strength of the pipe.

  The phenol resin which is a matrix resin may be either a resol type resin or a novolac type resin, but a resol type resin is particularly preferable. By using a phenol resin, heat resistance and flame retardancy are improved, and durability is remarkably improved as compared with the case where a polyester resin or the like is used as a matrix resin. Polyester resin starts burning at around 450 ° C, while phenol resin has high heat resistance, such as being able to acquire quasi-incombustibility in the Building Standards Act, so it is suitable as a chimney lining material. ing.

  The ratio of the phenol resin and the reinforcing fiber in the base layer is such that Ra is 0.7 to 0, where Ra represents the volume ratio of the phenol resin calculated by volume of phenol resin / (volume of reinforcing fiber + volume of phenol resin). 0.3, preferably 0.6 to 0.35, particularly preferably 0.55 to 0.45.

  The first reinforcing fiber member contains directional fibers, such as plain weave cloth, twill weave cloth, satin weave cloth, woven cloth such as woven cloth, roving cloth and uni roving cloth, and roving, etc. Unidirectional fiber materials and the like can be used.

  It is preferable that at least a part of the reinforcing fibers in the base layer is substantially arranged in the pipe circumferential direction. Further, for reinforcement in the axial direction of the pipe, it is preferable that reinforcing fibers arranged in the axial direction are also present. Here, the circumferential arrangement and the axial arrangement of the reinforcing fibers may be substantially arranged even if they are not strictly arranged in the circumferential direction and the axial direction of the pipe. That is, with respect to the reinforcing fibers arranged in the circumferential direction with the axial direction being 0 °, it is 90 ° to 90 ± 45 °, preferably 90 ° to 90 ± 30 °, more preferably 90 ° to 90 ± 15 °. As long as they are arranged. The fibers in the axial direction may be arranged between 0 ° to ± 45 °, preferably 0 to ± 30 °, more preferably 0 to ± 15 °.

  The continuous fiber in the woven fabric or unidirectional fiber material is wound one or more turns in the circumferential direction of the pipe, so that the properties of the reinforcing fiber can be used effectively, and the mechanical strength such as rigidity is improved. There is. At this time, the fibers in the circumferential direction may be continuous in a spiral shape. Further, it is sufficient that the reinforcing fibers are usually arranged in two directions of the circumferential direction and the axial direction, and the composition ratio (volume ratio) of the reinforcing fibers in the circumferential direction and the axial direction is 1 with respect to the circumferential direction. The axial direction is 0.2-2.

  Using a woven fabric with a composition ratio of warp and weft in an appropriate range, winding the yarn in the circumferential direction or winding it in a spiral at a predetermined angle from the circumferential direction, the fibers were arranged in two directions A fiber reinforced plastic is obtained.

  When a unidirectional fiber material is used, a fiber reinforced plastic arranged in two directions can be obtained by laminating layers arranged in the axial direction in addition to the layers arranged in the circumferential direction in the fiber direction.

  The reinforcing fibers used for the base layer are preferably carbon fibers or glass fibers in terms of heat resistance and acid resistance, and may be used in combination. In particular, when light weight and high strength are required, it is preferable to use carbon fiber, and when combined with glass fiber, the ratio of carbon fiber is preferably 60% or more by weight. Carbon fiber is particularly preferable.

  As the carbon fiber, either PAN-based or pitch-based can be used. What is necessary is just to select suitably considering a tensile strength, a tensile elasticity modulus, a price, etc. In terms of high strength and low price as carbon fiber, PAN-based carbon fiber and a tensile modulus of 200 GPa to 400 GPa are preferable.

  As a glass fiber, what is used for normal FRP use can be used. For example, E glass, C glass, T glass, etc. are mentioned. As the material used in the corrosion-resistant layer, it is also preferable to use a material excellent in acid resistance, a material called C glass, or the like.

  In addition to a layer containing a woven fabric or a unidirectional fiber material, the base layer is laminated with a layer containing a non-woven fabric such as a non-woven chopped strand mat and a surface mat to enhance the adhesion between the woven fabrics. You can also.

  The thickness of the base layer is determined from the ratio of the thickness of the corrosion-resistant layer described later and the thickness of the base layer.

<Configuration of corrosion-resistant layer>
The corrosion-resistant layer is a fiber-reinforced plastic layer made of a second reinforcing fiber member and a phenol resin, and is a layer that is provided on the inner surface side of the pipe from the base layer and is in direct contact with smoke.

  The ratio of the phenolic resin and the reinforcing fiber in the corrosion-resistant layer is such that Rb is 0.9 to 0, where Rb is the phenol resin volume mixing ratio calculated by the volume of the phenolic resin / (volume of the reinforcing fiber + volume of the phenolic resin). 0.5, preferably 0.8 to 0.6, particularly preferably 0.75 to 0.65. In this range, the base layer may be selected so as to be larger than the phenol resin volume mixing ratio Ra, but preferably Rb is 0.1 or more, particularly preferably 0.15 or more (for example, 0.2 or more) larger than Ra. Choose to be. The difference between Rb and Ra is usually 0.5 or less, and 0.3 or less under practical conditions.

  The corrosion-resistant layer needs to have heat resistance, flame resistance and acid resistance. By making the blending ratio of the phenolic resin in the corrosion-resistant layer larger than the blending ratio of the phenolic resin in the base layer, corrosion resistance such as acid resistance and heat resistance Both flame retardant properties can be improved. On the other hand, the brittleness due to the reduction of reinforcing fibers in the corrosion-resistant layer, for example, the occurrence of cracks, etc. is suppressed by being laminated with the base layer, and as a result, the deterioration caused by the cracks is prevented. It can prevent, and durability, such as acid resistance, improves more.

  The phenol resin, which is a matrix resin in the corrosion-resistant layer, may be either a resol type resin or a novolac type resin, but a resol type resin is particularly preferable. Further, from the viewpoint of layer continuity, it is preferable to use the same phenol resin as the base layer. In addition to improving the integrity of the corrosion-resistant layer and the base layer and improving the strength, there is an advantage that the manufacturing method is simplified.

  As the second reinforcing fiber member used in the corrosion-resistant layer, the above-mentioned woven fabric and unidirectional fiber material can be used, but nonwoven fabrics such as a chopped strand mat and a surface mat are preferable. More preferably, a non-woven fabric using short fibers such as a chopped strand mat is used. The length of the short fiber is usually about 100 mm or less, for example, about 40 to 60 mm, about 3 to 40 mm, and the like. Preferably, it is about 3-60 mm. By using a non-woven fabric made of short fibers, damage to the matrix resin due to curing shrinkage and the like can be suppressed while obtaining a high matrix resin content, so that durability such as acid resistance is further improved.

  The thickness of the corrosion-resistant layer is improved by its existence, but is preferably 0.3 mm or more, and more preferably 0.5 mm or more. Since it is not economical if it is too thick, for example, it is preferably 3 mm or less, and even if it is 1.5 mm or less, for example 1 mm or less, sufficient performance can be exhibited. In relation to the thickness of the base layer, the ratio of the thickness of the corrosion-resistant layer to the base layer is preferably in the range of 5:95 to 60:40, more preferably 5:95 to 40:60, particularly 5:95 to 20:80. Typically 10:90 in a preferred example. The thickness can be adjusted by appropriately changing the type and number of layers of the fiber reinforced members used.

  Further, the surface of the reinforcing fiber used for the base layer and the corrosion-resistant layer may be subjected to a necessary treatment such as a silane coupling treatment. Furthermore, in phenol resin, metal oxide (titanium oxide, barium sulfate, magnesium oxide, zinc oxide, alumina, talc, silica), phosphoric acid compound (metal phosphate, organic phosphate, ammonium polyphosphate), metal Flame retardant fillers such as hydroxides (aluminum hydroxide, magnesium hydroxide, calcium hydroxide), nitrogen-containing compounds (isocyanurate compounds, isocyanuric compounds, guanidine compounds, urea compounds), and other additives May be included.

  Further, in order to prepare the surface of the lining pipe, a surface layer may be further provided on the outer surface of the base layer. This surface layer is additional and is not intended to improve performance. As the surface layer, those using non-woven fabric as reinforcing fibers are preferable, and the matrix resin is preferably a phenol resin.

<Manufacturing method and chimney repair method>
In order to produce a fiber reinforced plastic having a base layer and a corrosion-resistant layer, ordinary methods such as a hand lay-up method, a sheet winding method, and a filament winding method may be used.

  For example, in the filament winding method, a long mandrel of a second reinforcing fiber member such as a non-woven fabric used for a corrosion-resistant layer is wound on a rotating mandrel so as to have the required number of layers while impregnating with a phenol resin. . Then, it winds so that it may become a required number of layers, making the elongate thing of 1st reinforcing fiber members, such as a woven fabric used for a base material layer, impregnate a phenol resin. Thereafter, the resin is cured at room temperature or by heating, and then decentered to obtain a product.

  There are two types of phenolic resins, a room temperature curing type and a heat curing type, and even the same phenolic resin may have different heat resistance, strength, and rigidity depending on the curing temperature. When high heat resistance and high flame retardancy are required, it is usually preferable to perform heat curing. The heating temperature may be appropriately set according to the material, but is, for example, 40 ° C or higher, preferably 50 ° C or higher, and is usually 200 ° C or lower, preferably 150 ° C or lower, more preferably 100 ° C or lower. On the other hand, when high heat resistance and flame retardancy are not required, curing may be performed at room temperature, in which case the manufacturing cost can be reduced.

  The manufactured lining pipe is preferably used for a chimney exposed to a temperature of 120 to 250 ° C, preferably 150 to 220 ° C.

  An example of the manufactured lining pipe is shown in FIG. The diameter and length of the lining pipe are appropriately changed according to the size of the chimney to be applied. As shown in FIG. 1, a lining pipe 1 is provided with an attachment metal band 2 for attachment to an existing chimney. Usually, since it installs from a chimney upper part in the case of installation, length is about 1m-10m, for example.

  In the chimney repair method using the lining pipe of the present invention, the lining pipe is lifted by a heavy machine such as a crane, and is inserted from the upper part of the existing chimney, and a necessary number of lining pipes are stacked.

  FIG. 2 shows a state in which the lining pipe 1 is installed inside the existing iron chimney 3. Fig.2 (a) is sectional drawing cut | disconnected by the surface containing an attachment metal band, FIG.2 (b) is an enlarged view of the attaching part part seen from the horizontal direction. In this way, the protrusion of the mounting metal band and the lining pipe holding metal fitting 4 provided on the existing iron chimney 3 are connected by the bolt / nut 6 using the connection metal fitting 5. In this figure, the connection is made at four places, but there is no particular limitation at six places or eight places.

  The upper and lower connections or sealing of the lining pipe may be performed by a known method. For example, as described in JP-A-57-204718, the upper end of the lining pipe has a double tubular receptacle, and the lower end Is inserted into the upper end portion having the double tubular receiving portion, so that the pipes can be stacked. And a sealing part required can be maintained by filling a heat insulation and noncombustible material, such as a glass chop, in a junction part.

  In the repaired chimney, a space is created between the existing chimney and the lining pipe as shown in FIG. The presence of this space improves the heat insulation, and can easily absorb the difference in expansion coefficient between the existing chimney and the lining pipe accompanying heating and cooling. The space between the existing chimney and the lining pipe is 50 to 500 mm, preferably 100 to 400 mm.

  According to such a construction method, the construction period is significantly shortened as compared with the replacement of the chimney, and the durability is much higher than that of the painting method using the acid resistant paint.

<Example 1>
Reinforcing fiber members used for each layer were selected as follows, and a fiber-reinforced plastic lining pipe was manufactured as follows by a filament winding molding method.

Corrosion-resistant layer: One layer of carbon fiber chopped strand mat having a basis weight of 50 g / m ² ;
Base layer: 8 layers of carbon fiber plain weave cloth with a basis weight of 300 g / m ² ;
Surface layer: One layer of glass fiber surface mat having a basis weight of 30 g / m ² .

  In order to form a corrosion-resistant layer, the above-mentioned carbon fiber chopped strand mat (long length of 300 mm) was impregnated with a resol-based phenol resin, while the strand mat was made against a mandrel having a diameter of 1 m and a length of 6.5 m. One layer was wound while the ends overlap each other by 50 mm. Subsequently, to form the base layer, the above-mentioned phenol resin is impregnated into a plain woven cloth (long length of 300 mm) using the above-mentioned PAN-based carbon fiber having a tensile elastic modulus of 230 GPa, and the cloths overlap each other by 50 mm. First, a single layer of carbon fiber plain weave cloth was wound over the entire length direction, and the layers up to the second to eighth layers were sequentially laminated. Furthermore, in order to form a surface layer, the above-mentioned glass fiber surface mat (long one having a width of 300 mm) was wound for one layer while the ends of the surface mat overlap each other by 50 mm.

  Thereafter, the resin was cured by heating at 60 ° C. for 120 minutes. After the mandrel was decentered, the end face was molded to obtain a cylindrical lining pipe. The finished dimensions were an inner diameter of 1 m, a length of 6.0 m, and a thickness of 5.5 mm.

  Moreover, the volume mixing ratio Rb of the phenol resin in the corrosion-resistant layer is 0.75, and the volume mixing ratio Ra of the phenol resin in the base layer is 0.45. The corrosion-resistant layer has a thickness of 0.6 mm, and the base layer has a thickness of 4.5 mm.

<Example 2>
Reinforcing fiber members used for each layer were selected as follows, and a fiber-reinforced plastic lining pipe was manufactured as follows by a filament winding molding method.

Corrosion resistant layer: (1) One layer of carbon fiber chopped strand mat with a basis weight of 50 g / m ² ;
Base layer: (2) 3 layers of glass fiber plain weave cloth with a basis weight of 200 g / m ² ;
(3) Three layers of glass fiber roving cloth with a basis weight of 800 g / m ² ;
Surface layer: (4) One layer of a glass fiber surface mat having a basis weight of 30 g / m ² .

  In this example, the reinforcing fibers (1) to (1) were impregnated with a phenol resin in the same manner as in Example 1 except that the materials of the above (2) and (3) were used as the reinforcing fiber member of the base layer. After winding around a mandrel so as to have the number of layers described above in the order of (4), the same processing was performed to obtain a lining pipe having an inner diameter of 1 m, a length of 6.0 m, and a thickness of 5.5 mm.

  The volume mixing ratio Rb of the phenol resin in the corrosion-resistant layer is 0.75, and the volume mixing ratio Ra of the phenol resin in the base layer is 0.55. The corrosion-resistant layer has a thickness of 0.6 mm, and the base layer has a thickness of 4.5 mm.

<Comparative Example 1>
Except for using an unsaturated polyester resin as a matrix resin, the reinforcing fiber member used for each layer and the number of wound layers were set in the same manner as in Example 2, and a fiber-reinforced plastic lining pipe was manufactured by a filament winding molding method. .

  That is, as in Example 1, while impregnating the unsaturated polyester resin, the reinforcing fiber members (1) to (4) described in Example 2 were wound around the mandrel so as to have the above-mentioned number of layers. Thereafter, the same processing was performed to obtain a lining pipe having an inner diameter of 1 m, a length of 6.0 m, and a thickness of 5.5 mm.

<Comparative example 2>
In Example 1, the same as in Example 1 except that a plain woven cloth using a PAN-based carbon fiber having a weight per unit area of 300 g / m ² and a tensile elastic modulus of 230 GPa was used as the corrosion-resistant layer. A lining pipe was obtained. This structure corresponds to the structure in which the carbon fiber cloth of the base layer is increased from 8 layers to 9 layers without forming the carbon fiber chopped strand mat of the corrosion resistant layer in Example 1. The finished dimensions were an inner diameter of 1 m, a length of 6.0 m, and a thickness of 5.4 mm.

  Moreover, the volume mixing ratio Rb of the phenol resin in the corrosion resistant layer is 0.45, and the volume mixing ratio Ra of the phenol resin in the base layer is 0.45. The corrosion-resistant layer has a thickness of 0.5 mm, and the base layer has a thickness of 4.5 mm.

<Evaluation of heat resistance and acid resistance>
From the pipes obtained in Examples and Comparative Examples, a strip-shaped test piece having an axial length of 150 mm and a pipe circumferential length of 20 mm was cut out and exposed to the following high temperature conditions or acidic conditions, and then the tensile strength. And / or bending strength was measured and heat resistance and acid resistance were evaluated. The bending test was conducted by a three-point bending method with a fulcrum distance of 100 mm.

  Heat resistance test: Measures tensile strength and bending strength after exposure at 200 ° C. for 500 hours.

  Acid resistance test (1): A test piece with the corrosion-resistant layer side down was held near the liquid surface so that only the corrosion-resistant layer side was in contact with the acid solution at 140 ° C. and 80% sulfuric acid for 500 hours. The bending strength is measured after immersion.

  Acid resistance test (2): A test piece with the corrosion-resistant layer side down was held near the liquid surface so that only the corrosion-resistant layer side was in contact with the acid solution at 100 ° C. and 20% hydrochloric acid for 500 hours. The bending strength is measured after immersion.

  The present invention is usefully used for chimney repair.

It is a figure which shows the lining pipe of this invention. It is a figure which shows attachment of the lining pipe of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lining pipe 2 Mounting metal band 3 Existing iron chimney 4 Lining pipe holding metal fitting 5 Connection metal fitting 6 Bolt and nut

Claims (10)

A lining pipe for a chimney,
(A) a first reinforcing fiber member containing fibers arranged at least substantially in the circumferential direction and a base layer made of a phenol resin;
(B) A layer in contact with smoke provided on the inner surface side of the base layer, which is composed of the second reinforcing fiber member and the phenol resin, and calculated by the volume of the phenol resin / (volume of the reinforcing fiber + volume of the phenol resin). A fiber-reinforced plastic lining pipe having a corrosion resistance layer in which the volume blending ratio of the phenol resin is larger than the volume blending ratio in the base layer.   The lining pipe according to claim 1, wherein the first reinforcing fiber member in the base layer contains fibers in at least two directions of fibers arranged substantially in the circumferential direction and fibers arranged substantially in the axial direction.   The lining pipe according to claim 1 or 2, wherein the first reinforcing fiber member in the base layer is a woven fabric or a unidirectional fiber material.   The volume ratio of phenol resin calculated by the volume of phenol resin in the base layer / (volume of reinforcing fiber + volume of phenol resin) is represented by Ra, and the volume of phenol resin in the corrosion-resistant layer / (volume of reinforcing fiber). The lining pipe according to any one of claims 1 to 3, wherein Rb is 0.1 or more larger than Ra when the volume mixing ratio calculated by + volume of phenol resin is represented by Rb.   The lining pipe according to any one of claims 1 to 4, wherein the second reinforcing fiber member in the corrosion-resistant layer is a nonwoven fabric.   The lining pipe according to claim 5, wherein the second reinforcing fiber member in the corrosion-resistant layer is a nonwoven fabric made of short fibers.   The process of lowering the lining pipe according to any one of claims 1 to 6 provided with an attachment from the upper part of the chimney into the chimney and connecting with the holding fitting attached to the inside of the chimney is repeated, and the lining pipe is installed inside the chimney. A chimney repair method characterized by stacking.   The chimney repair method according to claim 7, wherein a space between the inner wall of the chimney and the lining pipe is set to 50 mm to 500 mm.   A chimney in which the lining pipe according to any one of claims 1 to 6 is stacked inside the chimney.   The chimney according to claim 9, wherein the space between the inner wall of the chimney and the lining pipe is 50 mm to 500 mm.

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