JPH0359317B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] This invention has a structure that can maintain suitable flexibility and excellent abrasion resistance even at high temperatures in the pneumatic transportation of solid materials such as powder and scaly materials. The present invention relates to a high-temperature abrasion-resistant hose with excellent flexibility capable of transferring high-temperature fluids such as reaction solids in a high-temperature reactor and high-pressure feeding, and a method for forming the high-temperature abrasion-resistant hose. [Prior Art] Conventionally, flexible and abrasion-resistant hoses include hoses in which abrasion-resistant material is embedded in the inner rubber surface of the hose, as disclosed in Japanese Utility Model Application Publication No. 58-142474, and JP-A-55-129433 discloses a rubber lining material in which particles of wear-resistant material are mixed with rubber, and JP-A-60-31574 discloses a rubber hose lined with ceramic tiles. ing. In all of the above configurations, the wear-resistant material and the rubber material are exposed to the flow surface of the fluid flowing inside the hose. Therefore, when the fluid is an abrasive fluid such as slurry or powder, conventionally used hoses tend to wear out quickly due to abrasion of the rubber material, causing problems such as work line stoppages. Ta. Therefore, in the earlier application, the applicant group proposed a flexible hose having an improved sintered wear-resistant inner layer that does not expose the rubber-like substance to the fluid flow surface, as shown in Japanese Utility Model Application Publication No. 62-45491. It was invented. The above is the prior art of hose systems having a flexible sintered wear-resistant inner layer. [Problems to be Solved by the Invention] Generally, when transporting fluids, it is extremely advantageous to have excellent flexibility in a piping line that has an inner layer of a sintered wear-resistant material with extremely high wear resistance. In other words, curvature and flexibility are extremely practical in operation, and flexible hose configurations are important factors for installing, removing, inspecting piping, preventing vibrations, and moving transportation locations. In particular, for flexible high-temperature hoses, since rubber-like materials are used, the polymer used for the hose wall must have a heat resistance of at least 200°C or higher, and have low heat dissipation properties with a low heat storage capacity. It is also important to ensure that the wall thickness is as small as possible, and that the softening of the flexible rubber-like material due to temperature is suppressed as much as possible to ensure excellent rubber-like properties at high temperatures. This is important both for exhibiting elasticity and for long-term durability. The above are the structure of the hose wall of the present invention and the conditions for the polymer used for the hose wall. Furthermore, in the case of reinforcing materials, properties that easily soften or melt at high temperatures are also inappropriate in terms of reinforcing properties at high temperatures. It is important to use a high-strength material that has sufficient strength at high temperatures. The above are the conditions for the reinforcing material used in the hose wall of this invention. Conventional hoses use a hose configuration consisting of intermediate rubber, reinforcing layer, outer rubber, etc.
Although ordinary heat-resistant rubber has some degree of durability at high temperatures, it cannot avoid softening, so its physical properties change significantly at high temperatures. Therefore, the creep of rubber-like elastic bodies is greatly accelerated by operations such as bending and flexibility during use.
This causes uneven fluctuation damage and significantly reduces durability, and in conventional hose configurations, the practical limit is around 100°C. Therefore, the high-temperature wear-resistant hose of the present invention has an end ring made of the same material as the ceramic unit of different diameter tubes made of a sintered wear-resistant material such as alumina ceramic, which is formed in the inner layer of the hose. In forming the inner layer of the material, we searched for a composition that would meet the above conditions for the polymer and reinforcing material used in the hose wall, and created a hose wall with a simple structure that does not make it as thick as possible, and can be used at high temperatures of 200℃ or higher. The object of the present invention is to provide a high-temperature abrasion-resistant hose that exhibits minimal deterioration in physical properties due to temperature, and a method for molding the high-temperature abrasion-resistant hose. [Means for Solving the Problems] Conventional organic polymers are unsuitable as polymers for use in the hose wall constituting the high-temperature wear-resistant hose of the present invention, and rubber that can be used in a temperature range exceeding 200°C is used. Examples of the elastic body include silicone rubber having a skeleton of siloxane bonds (Si-O-Si). In addition, silicone rubber has a thermal conductivity that is more than twice that of general synthetic rubber, and has heat dissipation properties, and its gas permeability is about that of polyethylene.
Although silicone rubber has excellent permeability, which is 100 times higher and 10 to 20 times higher than that of general synthetic rubber, silicone rubber generally has the following drawbacks. (a) Due to the unique hydrolysis of silicone rubber, high-temperature direct steam vulcanization is not possible. (b) Due to its low tearability, there is a risk of cracking when the connecting rubber is subjected to repeated compression and stretching. (c) Because silicone raw rubber compounds are non-adhesive, it is not as easy to mold hoses as with ordinary unvulcanized rubber, and sheet-like laminated molding is difficult and requires sufficient adhesive. can be,
In particular, it is not easy to join the narrow parts between the wear-resistant materials. (d) Due to its structural stability, silicone rubber has low adhesion to different materials, especially chemical fibers, and requires special adhesive treatment, and unlike organic polymers, silicone rubber has topping and friction operations using a calendar. In this case, it is difficult to easily obtain a sufficiently stable pressure-resistant reinforcing structure. In order to solve the above problem, high-temperature hot air vulcanization can be considered as a countermeasure for (a), but this high-temperature method is not easy to work with. As the easiest method, it is preferable to use a high viscosity silicone rubber such as a viscous fluid type that cures at room temperature or a semi-solid type that is higher than grease. In other words, the fluid type is adhesive and can be easily inserted and bonded into narrow areas between sintered wear-resistant materials.
The outer recessed part can be easily filled with a semi-solid type and bonded. This room-temperature-curing silicone rubber can be easily adhered to sintered wear-resistant materials such as ceramics, and if the required curing time is allowed, sufficient strength can be obtained, so there is no need for vulcanization. Therefore, there is no need for a step in which it comes into direct contact with steam, and there is no risk of hydrolysis. As a countermeasure for (b), silicone rubber is made of aromatic polyamide [abbreviation]
By mixing it with short fibers of about 2 to 8 mm of ARAMID fiber (trade name, Technora, Kevlar), the tensile strength and tear resistance in all directions are significantly improved. Furthermore, since the aramid fibers used as the reinforcing material are mixed in a non-directional manner, the solid silicone rubber maintains sufficient compressibility and extensibility, forming a high-strength rubber-like elastic body. be. This aramid fiber is heat resistant and can withstand long-term use at 200°C, and does not melt when heated, so it is ideal for high-temperature hoses because its strength does not deteriorate significantly due to temperature. In addition, in order to increase the adhesive strength with silicone rubber, it is preferable to apply RFL (resorcinol formalin latex) treatment as in the case of general synthetic fibers, but when using uncured viscous silicone rubber, Since it has extremely good compatibility with silicone rubber, sufficient adhesive strength can be obtained without any adhesive treatment. The above mixing ratio is by weight, silicone rubber:
Aramid fiber = 100: about 5 to 10, but if the amount of aramid fiber is small, the strength tends to decrease, and if the amount of fiber is large, the elasticity tends to decrease, so choose accordingly, taking into account the characteristics of the hose. be done. As a countermeasure for (c), it is easier to mold a hot-vulcanized silicone raw rubber compound than a hot-curable silicone raw rubber compound. It is easy to set up the injection, and it can be laminated one after another on cured silicone rubber. By molding compound silicone rubber, there is no risk of air intervening between the laminated layers, and thickness accuracy can be obtained. High-viscosity silicone rubber can be packed between wear-resistant materials by extrusion, like a cylindrical toothpaste, or it can be applied by adjusting the viscosity and using a putty tool. You can also do that. In the case of low-viscosity silicone rubber, it is also possible to apply a thin film with a brush and repeat curing and lamination. Regarding countermeasure (d), ordinary silicone compounds have low adhesive strength with different materials, and cured silicone rubber is chemically stable, making it difficult to firmly adhere to materials made of different materials. However, uncured fluid silicone rubber and cured silicone rubber are easily adhered to each other, and after the bond is cured, the bond is uniformly and firmly bonded to the extent that the bonded surface is not observed at all.
Utilizing this feature, it can be bonded to chemical fiber materials that are normally difficult to bond to. That is, by impregnating a woven fabric of processed fiber yarn with a fluid type silicone rubber, the fibers of the twisted yarn,
Silicone rubber is adsorbed into the gaps between the twisted yarns by capillary action. This adsorbed silicone rubber is
Since it is wet and adheres to both the inner and outer surfaces of the woven fabric and the entire middle part, when this silicone rubber is cured, it is present on the inner and outer sides and in the middle of the fabric, and all of them form a cured state. . In other words, as mentioned in the countermeasure section (b) above,
This is similar to when short fibers are mixed into silicone rubber, and all the fiber threads of the woven fabric are encapsulated in the silicone rubber, and the woven fabric and silicone rubber are firmly bonded. Ru. Therefore, in order to join the silicone rubber-impregnated cloth c to the cured silicone rubber material a containing short fibers inserted between the sintered wear-resistant materials and the cured silicone rubber material b applied to the outer surface of the sintered wear-resistant materials, After applying uncured fluid type silicone rubber d to the outer surfaces of a and b, and before curing, attaching silicone rubber impregnated cloth c, fluid type silicone rubber d becomes a binder, a, b, c
are joined together and become a single piece after curing. This woven fabric is intended to enhance pressure resistance as a hose and reinforcement performance for holding wear-resistant materials, and because each part is firmly bonded,
It provides high reinforcing properties. By utilizing the above measures, a more effective method of forming a hose can be obtained. In addition, as mentioned in the section of the problem to be solved, the high temperature wear-resistant hose of the present invention has the following features:
The polymer used in the hose wall must be at least 200
A thin-walled material that has heat resistance above ℃, has a small possible heat storage capacity, has heat dissipating properties, does not soften or change its physical properties as the temperature rises, and exhibits excellent rubber-like elasticity at high temperatures. For example, it is possible to have a simple structure that does not require a top rubber or the like and can easily dissipate heat. Therefore, a sintered wear-resistant material such as alumina ceramics is used for the inner layer of the hose, and as the polymer used as the connecting material, as mentioned above, organic polymers are inappropriate, and silicone rubber with a skeleton of siloxane bonds is used. It is heat resistant to temperatures above 200°C, has excellent heat dissipation properties due to its excellent thermal conductivity, and has little softening or change in temperature as the temperature rises, and maintains excellent rubber-like elasticity at high temperatures, making it a good choice as a hose. This provides excellent operability. Therefore,
Good results can be obtained by taking measures against the low tear resistance, which is a drawback of silicone rubber (by incorporating short fibers). However, only silicone rubber is used in some narrow areas where adhesion is important. Furthermore, the hose is constructed so that the wall thickness is kept to the minimum possible level. That is, the high temperature abrasion resistant hose of the present invention is
The required number of different diameter pipe ceramic units made of sintered wear-resistant material such as alumina ceramics are assembled into the inner layer of the hose with a loose fit between the large diameter part and the small diameter part.
Ceramic end rings are provided at both ends, and the ceramic units and the ceramic end rings are connected to each other using silicone rubber and/or aromatic polyamide short fiber-mixed silicone rubber. This constitutes a high-temperature wear-resistant hose characterized by a structure in which a reinforcing layer of an appropriate number of plies of rubber-bonded aromatic polyamide short fiber cloth is adhesively coated. Next, a preferred method for forming the high temperature wear-resistant hose of the present invention will be described. That is, the required number of ceramic tube units of different diameters connected to one end of the ceramic end ring inserted on the core bar for hose molding are sequentially assembled in a loosely fitted state,
The free fitting part between the inner and outer surfaces of the large diameter part and the small diameter part of the different diameter pipe, and between the outer surface of the end ring of the same diameter as the small diameter part and the inner surface of the large diameter part, has room temperature hardening fluidity. type of silicone rubber or aromatic polyamide-based short fiber-mixed silicone rubber is injected and connected to connect the required number of units, and the small diameter part of the connected end is butted with the end ring of the other end of the same diameter, The outer periphery is joined with the same silicone rubber and reinforcing material as above to form the wear-resistant inner layer of the hose. The semi-solid type silicone rubber is filled with silicone rubber mixed with aromatic polyamide short fibers, and the outside is pre-impregnated with room temperature curable fluid type silicone rubber similar to the above, and the inside and outside are sufficiently filled. High-temperature wear-resistant product characterized by bonding silicone rubber bonded aromatic polyamide short fiber cloth connected by a rubber layer as a reinforcing material, and molding by folding and fixing both ends of the reinforcing material to a flange fixing ring. This is a method of forming a hose. [Function] The high-temperature wear-resistant hose of the present invention is characterized by an easy-to-dissipate structure consisting of only three layers: a sintered wear-resistant inner layer, a connecting silicone rubber, and an aromatic polyamide fiber cloth. It is constructed by a combination of ceramic tube units with different diameters whose inner layer is made of a sintered wear-resistant material such as alumina ceramics, and the parts that fit loosely between the units and other parts that require flexibility of the entire structure have physical properties depending on temperature. We do not use any organic polymers that have a large change in temperature, and we use silicone rubber, which is mainly made of siloxane bonds and is heat resistant at high temperatures, has thermal conductivity, has a small heat storage capacity, and whose physical properties change little due to temperature. The hose uses aromatic polyamide fiber cloth that is heat resistant and does not melt and whose physical properties change little due to temperature, and has the effect of suppressing temperature rises on the wall of the hose both in terms of structure and material. . In addition, the molding method uses room-temperature curable fluid type and semi-solid type that are easy to mold and have excellent adhesive properties, so molding is extremely easy, compared to heating type silicone rubber. It has the effect of preventing adhesion defects and uniformity of the product. In particular, an aromatic polyamide fiber fabric impregnated with a fluid type silicone rubber having excellent adhesive properties has excellent reinforcing properties at high temperatures. As described above, this high-temperature abrasion-resistant hose has the above-described structure, so it can withstand long-term use at high temperatures of 200° C., and its strength is extremely less likely to deteriorate due to temperature. Therefore, like conventional hoses, they soften and lose strength as the temperature rises.
The normal state is maintained without the danger of causing a major change in the shape of the hose that would cause problems in use. In addition, the inner layer of the hose of the ceramic unit with different diameters is connected with silicone rubber, which has extremely low temperature changes, and the outer layer is reinforced with aromatic polyamide fiber cloth, and all of the structural members are made of materials with low heat storage properties. composed of
Due to its relatively thin and simple structure, it has good heat dissipation, and there is almost no change in flexibility or other physical properties when used at high temperatures, and similar operability can be obtained from room temperature to high temperature. [Example] Molding of the high temperature wear-resistant hose of the present invention will be described in detail based on illustrative drawings. FIG. 1 is a partially cross-sectional front view of the high-temperature wear-resistant hose of the present invention, FIG. 2-A is an enlarged side view of a ceramic unit with different diameter pipes, and FIG. 2B is
It is an enlarged sectional view of the same. In the figure, 1 is a mounting bracket such as a flange, 2
is a flange fixing ring, 3 is a ceramic end ring, 4 is a ceramic unit with different diameter tubes, 4a is a large diameter part, 4b is a small diameter part, 5 is silicone rubber (for connection), 6 is an aromatic polyamide short fiber Mixed silicone rubber (for filling the recess R), 7 is an aromatic polyamide fiber cloth bonded to silicone rubber, R is the recess formed between the large diameter parts, and PP is the loose fitting part. Molding with the combination of the above constituent members is performed by attaching a ceramic end ring 3 to the left end on the core bar for hose molding.
After inserting the required number of ceramic units 4 of different diameter pipes, the required number of ceramic units 4 of different diameter pipes are assembled in a loosely fitted state. The loose fitting part PP between the outer peripheral surface of the small diameter part and the inner peripheral surface of the large diameter part is injected with room temperature curing fluid type silicone rubber,
The required number of different diameter ceramic tube units 4 are joined to the other end. At the right end, the small diameter part 4b of the different diameter tube ceramic unit 4 is butted against the ceramic end ring 3 of the same diameter, and the outer periphery is They are joined with similar silicone rubber and reinforcing material, and if necessary, the silicone rubber-bonded aromatic polyamide fiber cloth 7 is adhered and firmly fixed to form the wear-resistant inner layer of the hose. Next, the recesses R formed between the inner layers of the wear-resistant material are filled with room-temperature-curable, semi-solid type aromatic polyamide short fiber-mixed silicone rubber 6, and cured at room temperature. After curing, the wear-resistant inner layer (3+4 ) and the outer surface of the silicone rubber mixed with aramid short fibers for filling the recesses R. A fluid type silicone rubber is applied as an adhesive to form an adhesive layer on the outer surface of the silicone rubber mixed with aramid short fibers for filling the recess R. A silicone rubber bonded aromatic polyamide (aramid) fiber cloth impregnated with room temperature cured silicone rubber is bonded as a reinforcing material, and both ends of this aramid fiber cloth are folded back and fixed to the flange fixing ring 2. This high-temperature wear-resistant hose is formed by molding. The materials used in the above example are the mounting bracket 1 such as a flange and the flange fixing ring 2.
SS41 steel is used, and the joints are shotplast treated. The ceramic end ring 3 and the ceramic unit 4 are made of 90% alumina.
Alumina ceramics were used, and the surface was cleaned with alcohol. The connecting silicone rubber 5 is a fluid type made by Shin-Etsu Chemical Co., Ltd., and the aromatic polyamide-based short fiber-containing silicone rubber 6 is used as a filler for the recesses R formed between the inner layers of the wear-resistant material. The aromatic polyamide short fiber was Teijin's Technora T-320, 6 mml, and the silicone rubber was a semi-solid type from Shin-Etsu Chemical Co., Ltd. The mixing ratio of the aramid short fiber was 10%. And so. Silicone rubber bonded aromatic polyamide fiber fabric is
The silicone rubber used as a reinforcing material on the outermost side was a fluid type that hardens at room temperature from Shin-Etsu Chemical Co., Ltd., and the aromatic polyamide fiber cloth used was Technora MF1001 from Teijin Ltd. The results of the heat resistance test of the hose molded in the above example are shown in the following table.

〔Effect of the invention〕

The high-temperature wear-resistant hose of the present invention has the functions described above, and in molding, by selecting and using silicone rubber that has excellent processability and appropriate physical properties, defects caused by product variations during high-temperature use are avoided. The occurrence is prevented and at a high temperature of 200℃,
Suitable pressure resistance, flexibility, bending fatigue resistance of the hose,
The hose's ability to maintain its condition at room temperature sufficiently guarantees long-term use. In the case of conventional heat-resistant hoses made of organic polymers and fused synthetic fibers, the heat resistance limit is low, so it is necessary to lower the temperature of the fluid before transferring it, or to use non-flexible pipes. In the production line, problems such as line stoppage due to defects or damage in the conventional process are eliminated, and the hose's characteristics are fully demonstrated for a long period of time at high temperatures of 200℃.
This has excellent practical effects.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a high-temperature wear-resistant hose of the present invention, FIG. 2-A is an enlarged side view of a ceramic unit with different diameter tubes, and FIG. 2-B is an enlarged cross-sectional view of the same. DESCRIPTION OF SYMBOLS 1...Mounting fittings for flanges, etc., 2...Flange fixing ring, 3...Ceramic end ring, 4 ...Different diameter pipe ceramic unit, 4a...Large diameter part, 4b
...Small diameter part, 5...Silicone rubber (for connection), 6
...Silicone rubber mixed with aromatic polyamide short fibers (for filling the hollow portion R), 7...Silicone bonded aromatic polyamide fiber cloth, PP...loose fitting portion, R... hollow portion.

Claims (1)

[Scope of Claims] 1. A required number of ceramic pipe units of different diameters made of a sintered wear-resistant material such as alumina ceramics are assembled in the inner layer of the hose in a loosely fitted state with a large diameter part and a small diameter part, and With ceramic end rings,
The ceramic units and the ceramic end rings are connected to each other by silicone rubber and/or silicone rubber mixed with aromatic polyamide short fibers, and on the outside of the inner layer of the sintered wear-resistant material, a silicone rubber bonded aromatic polyamide fiber cloth is applied. A high-temperature wear-resistant hose characterized by a structure that is adhesively coated with a reinforcing layer with a large number of plies and has mounting fittings such as flanges on both ends. 2. Sequentially assemble the required number of ceramic units of different diameter pipes connected to one end of the ceramic end ring inserted on the core bar for hose forming in a loosely fitted state, and insert the inner and outer surfaces of the large diameter part and the small diameter part of the different diameter pipes. Room-temperature curable fluid type silicone rubber or aromatic polyamide short fiber-mixed silicone rubber is injected into the loose fitting part between the outer surface of the end ring, which has the same diameter as the small diameter part, and the inner surface of the large diameter part. The required number of units are connected, and the small diameter part of the connected end is butted against the end ring of the other end of the same diameter, and the outer periphery is covered with the same silicone rubber and reinforcing material as above. After joining, the hollows formed between the inner layers of the wear-resistant material are filled with silicone rubber that hardens at room temperature and contains semi-solid aromatic polyamide short fibers, and the inner layers of the wear-resistant material of the hose are filled. A silicone rubber-bonded aromatic polyamide fiber cloth, which is pre-impregnated with room-temperature curable fluid type silicone rubber similar to the above and connected inside and outside with a sufficient rubber layer, is bonded to the outside as a reinforcing material. . A method for molding a high-temperature wear-resistant hose, characterized in that both ends of the reinforcing material are folded back and fixed to a flange fixing ring of a mounting fitting such as a flange.