MXPA00001775A - Heating furnace tube, method of using the same, and method of manufacturing the same - Google Patents

Abstract

A heating furnace tube, a method of using the same and a method of manufacturing the same which have been developed with a view to eliminating inconveniences occurring when a carbon-containing fluid is made to flow in the heating furnace tube. The heating furnace tube which comprises a rare earth oxide particle distributed iron alloy containing 17-26 wt.%of Cr and 2-6 wt.%of Al. The method of manufacturing this heating furnace tube which comprises the steps of forming or insertingan insert metal on or into at least one of a joint end portion of one heating furnace tube element and that of the other heating furnace tube element, bringing these two joint end portions into pressure contact with each other directly or via an intermediate member, and diffusion welding the two heating furnace tube elements to each other by heating the insert metal.

Description

HEATING OVEN TUBE, METHOD FOR USING THE HEATING OVEN TUBE AND METHOD TO MANUFACTURE THE HEATING OVEN TUBE TECHNICAL FIELD The present invention relates to a heating furnace tube, a method for using the heating furnace tube, and a method for manufacturing the heating furnace tube, and more particularly to a heating furnace tube whose problems are carbonization and carburization during high temperature operation, such as a fractionating pipe of an ethylene plant, a method for using said heating furnace pipe and a method for manufacturing said heating furnace pipe.

TECHNICAL BACKGROUND In a fractionation tube of an ethylene plant used as a heating furnace tube, for example, carbonization is a problem, wherein the carbon is precipitated and deposited on the inner surface of the tube in the gas atmosphere including carbon, as for example hydrocarbon, when the temperature is on the scale of temperature where the precipitation of carbon occurs.

If carbonization is generated on the inside surface of the heating furnace tube, serious problems such as overheating and plugging may occur during the operation of the plant. Therefore, decarbonization to remove the deposited charcoal by incinerating in a high temperature steam atmosphere must be carried out frequently, and to carry out decarbonization, the operation of the plant must be temporarily stopped, which causes a considerable fall in the productivity. The technologies that have been developed to solve this problem include the construction of a heating furnace tube made of oxide film material containing Ai on the surface created by adding 1-10% Ai to ferric alloy, or material with a layer of High content of Ai created by aluminizing the base alloy surface. In that conventional technique, however, the resistance to carbonization is in fact improved, but it is not yet sufficient to use the tube as a heating furnace tube in a current industrial furnace. With the above-mentioned under consideration, it is an object of the present invention to provide a heating furnace tube which has good resistance to carbonization and can avoid a drop in productivity due to decarbonization and a method for using the furnace tube of heating. In the case of a heating furnace tube that causes carburization, as is the case with a fractionation tube of an ethylene plant, the carburization depth on the inner surface of the heating furnace tube is regularly measured to avoid damage to the furnace tube. the heating furnace tube caused by carburization, and because the operation of the plant must be stopped with each measurement, the productivity drops considerably. Ferrous alloy strengthened by oxide dispersion (ODS), which is a highly ferritic chromium alloy (20 Cr-5-f-Fe) where the rare earth oxide is dispersed, is known to have a resistance to carburization and extremely excellent high temperature resistance compared to conventional materials, and is therefore applied to a heating furnace tube, including the joining method using fusion welding, friction welding, flame or mechanical bonding method. With the fusion welding method by TIG welding and electronic beam welding, which involves the fusion of bonding areas, however, the oxide particles float and the dispersion strengthening function, which is a characteristic of ODS ferrous alloy of rare earth, it is lost, dropping the high temperature by half or less. With the friction welding method, which does not involve the fusion of material, the resistance at high temperature does not fall much but the high pressure of assembly generates a large protuberance in the bonding area of the heating furnace tube, which will block the flow of fluid in the heating oven tube.

With strong solder welding, high heat resistance can not be expected because the melting point of the weld filler metal with a strong weld is much lower than that of the base material, and with the mechanical joining method, as a riveting and Screwing, maintaining air tightness at high temperature is extremely difficult, therefore both methods are unsuitable for joining the heating furnace tubes. In this way, conventional joining methods have difficulties in meeting the requirements for the joining areas of the heating furnace tubes, including carburization, air tightness and high reliability, as well as extremely high temperature resistance and carburization resistance. . With the above-mentioned under consideration, it is an object of the present invention to provide a heating furnace tube which can avoid a drop in productivity caused by the carburization measurement as much as possible, and a method for manufacturing the furnace tube of heating. As mentioned above, it is an object of the present invention to provide a heating furnace tube that can solve problems that occur to a heating furnace tube used for carbon containing fluid, as a hydrocarbon, a method for using the furnace tube of heating, and a method for manufacturing the heating furnace tube.

In other words, an object of the present invention is to provide a heating furnace tube that can implement extremely good carbonization resistance and can prevent a drop in productivity due to decarbonization as much as possible, and a method for using the tube. of heating furnace, as well as providing a heating furnace tube which can avoid a drop in productivity due to carburization measures as much as possible, and a method for manufacturing the heating furnace tube.

BRIEF DESCRIPTION OF THE INVENTION A heating furnace tube described in claim 1 is a heating furnace tube used for the fluid containing hydrocarbon or carbon monoxide, characterized in that the heating furnace tube is made of ferrous alloy ODS of rare earth containing 17 -26% Cr by weight and 2-6% by weight Ai. With this configuration, the rare earth ODS ferrous alloy containing 17-26% Cr by weight and 2-6% Ai by weight has extremely good carbonization resistance, therefore carbonization by the operation of a Ethylene can be minimized and the decarbonization range can be extended much larger than a conventional fractionation tube, and as a consequence, a drop in productivity due to decarbonization can be avoided.

A heating furnace tube described in claim 2 is characterized in that a component of heating furnace tube on one side made of ferrous alloy ODS of rare earth containing 17-26% Cr by weight and 2-6% of Ai by weight it is joined with a heating furnace tube component on the other side manufactured from the ferrous alloy ODS of rare earths mentioned above or heat resistant alloy by diffusion bonding through metal insert. With this configuration, at least one heating furnace tube component is made of rare earth ODS ferrous alloy having good resistance to carburization, therefore the replacement range of a heating furnace tube can be extended larger that a conventional heating furnace tube when used for an ethylene plant, and as a consequence, the cost for replacing the heating furnace tube due to the advance of carburization can be decreased, and a fall in productivity can be avoided due to the interval of plant closures because the measurement of carburization depth is extended. Also with this configuration, the cost of the plant can be considerably reduced by using a heating furnace tube component made of a heat resistant alloy for a part of a large heating furnace tube of an ethylene plant. A heating furnace tube described in claim 3 is the heating furnace tube described in claim 2 characterized in that the heating furnace tube is used to allow fluid flowing containing 100 ppm or less of S to flow in units of weight atomic, and is used on a temperature scale of 550 ° C-1000 ° C. With this configuration, the carbonization on ferrous alloy ODS of rare earth and heat resistant alloy can be minimized, therefore the decarbonization interval can be extended much longer than a conventional heating furnace tube, and consequently a drop in Productivity due to decarbonization can be avoided. A heating furnace tube described in claim 4 is the heating furnace tube described in claim 2 characterized in that the heating furnace tube has a short coupling tube to which the lateral joining edge of the furnace tube component of heating on one side and the joining side edge of the heating furnace tube component on the other side are inserted, and the heating furnace tube component on one side and the heating furnace tube component on the other side are joined through the short coupling tube by diffusion bonding in a state where the side joining edges of the heating furnace tube component on one side and the heating furnace tube component on the other side and the short coupling tube are contacted with pressure by a means of pressurization through metal insert which is deposited between the side joining edges of the heating furnace tube component on one side and the heating furnace tube on the other side and the short coupling tube. With this configuration, the side joining edge of the heating furnace tube component on one side and the side joining edge of the heating furnace tube component on the other side are connected by the short coupling tube, which makes the centering of the heating furnace tube component on one side and the heating furnace tube component on the other side easier in the manufacturing process. A heating furnace tube described in claim 5 is the heating furnace tube described in claim 4 characterized in that the pressurizing means consist of a tapered surface created by the outer surface of the short coupling tube and a tensioner that adjusts with the tapered surface and contact the short coupling tube in the radio direction. With this configuration, the side joining edges of the heating furnace tube component on one side and the heating furnace tube component on the other side can be safely in contact with pressure with the short coupling tube with a simple structure. A heating furnace tube described in claim 6 is the heating furnace tube described in claim 4 characterized in that the metal insert is formed by electrolytic deposition. With this configuration, the metal insert can be simply and securely disposed between the joining side edges of the heating furnace tube component on one side and the heating furnace tube component on the other and the short tube of heating furnace on the other side. coupling A heating furnace tube described in claim 7 is the heating furnace tube described in claim 2 characterized in that the heating furnace tube is used on a temperature scale of 550 ° C-1200 ° C. With this configuration, fragility fractures caused by fracture formation at 475 ° C can be avoided and a sufficient carburization resistance can be implemented. A method for using a heating furnace tube described in claim 8 is characterized in that the fluid containing hydrocarbon or carbon monoxide flows through the heating furnace tube made of ferrous alloy ODS of rare earth containing 17 -. 17-26% Cr by weight and 2-6% Ai by weight. With this structure, the ferrous alloy ODS of rare earth containing 17-26% Cr by weight and 2-6% of Ai has an extremely good carbonization resistance, therefore carbonization by the operation of an ethylene plant it can be minimized and the decarbonization interval can be extended much longer than a conventional fractionation tube, and as a consequence a drop in productivity due to decarbonization can be avoided. One method for using a heating furnace tube described in claim 9 is the method for using the heating furnace tube described in claim 8, characterized in that the heating furnace tube component on the other side made of resistant alloy to the heat is joined through metal insert by diffusion bonding. With this configuration, the metal furnace tube component made of heat resistant alloy is used for a part of a long heating furnace tube of an ethylene plant, which can decrease the cost of the plant considerably. One method for using a heating furnace tube described in claim 10 is the method for using the heating furnace tube described in claim 9, characterized in that the heating furnace tube allows fluid flowing containing 100 ppm or less to flow. of S in units of atomic weight, and is used on a temperature scale of 550 ° C - 1000 ° C. With this configuration, the carbonization on ferrous alloy ODS of rare earth and the heat resistant alloy can be minimized, therefore the decarbonization interval can be extended much longer than a conventional heating furnace tube, and as a consequence a drop in productivity due to decarbonization can be avoided. A method for manufacturing a heating furnace tube described in claim 11 is a method of manufacturing the heating furnace tube by joining a heating furnace tube component on a side made of ferrous alloy ODS of rare earth containing 17 - 26% Cr by weight and 2 - 6% Ai by weight with the heating furnace tube component on the other side made of rare earth ODS ferrous alloy or heat-resistant alloy by diffusion bonding through insert metal, characterized in that the manufacturing method comprises a method for forming or inserting the metal insert into at least one of the side joining edges of the heating furnace tube component on one side and the lateral joining edge of the heating component. heating furnace tube on the other side, a method to press contact the lateral joining edge of the heating furnace tube component on one side and the lateral joining edge of the heating furnace tube component on the other side directly or through an intermediate member, and a method for bonding by diffusing the heating furnace tube component on one side and the heating furnace tube component on the other side by heating the metal insert. With this configuration, at least one heating furnace tube component is manufactured to be a heating furnace tube made of rare earth ODS ferrous alloy with good resistance to carburization, hence the furnace tube replacement interval. Heating can be extended much longer than a conventional heating furnace tube when used in an ethylene plant, and as a consequence a drop in productivity can be avoided. A method of manufacturing a heating furnace tube described in claim 12 is the method of manufacturing the heating furnace tube described in claim 12 characterized in that the metal insert is formed by electrolytic deposition. With that configuration, the metal insert can be arranged simply and securely between the joining side edges of the heating furnace tube component on one side and the heating furnace tube component on the other side and the short coupling tube. A method of manufacturing a heating furnace tube described in claim 13 is the method of manufacturing the heating furnace tube described in claim 11, characterized in that the intermediate member is a short coupling tube to which the lateral edge of joining of the heating furnace tube component on one side and the joining side edge of the heating furnace tube component on the other side are inserted, and the heating furnace tube component on one side and the tube component of heating furnace on the other side are joined through the short coupling tube by making diffusion bonding in a state wherein the side joining edges of the heating furnace tube component on one side and the furnace tube component of the furnace heating on the other side and the short coupling tube are in contact with pressure by means of pressurization through the metal insert disposed between the joining side edges of the heating furnace tube component on one side and the heating furnace tube component on the other side and the short coupling tube. With this configuration, the lateral joining edge of the heating tube component on one side and the lateral joining edge of the heating oven tube component on the other side are joined through a short coupling tube as an intermediate member , which makes the centering of the heating furnace tube component on one side and the heating furnace tube component on the other side easier in the manufacturing process. One method of manufacturing a heating furnace tube described in claim 14 is the method of manufacturing the heating furnace tube described in claim 12, characterized in that the pressurizing means made of the tapered surface created on the outer surface of the short coupling tube and a tensioner that engages the tapered surface contacts the short coupling tube in the radio direction.

With this configuration, the side joining edges of the heating furnace tube component on one side and the heating furnace tube component on the other side can safely contact with pressure with the short coupling tube with a simple structure .

TABLE 1 Table 1 is a table on the result after examining the carbonization resistance, the oxidation resistance by high temperature and the mechanical characteristics of various alloy compositions including ferrous alloy ODS of rare earth heating tube furnace related to Claim 1 TABLE 2 Table 2 is a table on the result after examining the influence of S on carbonization resistance for ferrous alloy ODS of rare earth of the heating furnace tube related to claim 1, and for austenitic heat resistant alloy of a tube of conventional heating furnace.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a graph indicating the comparison of carbonization resistance between alloy Fe-20Cr-5 Ai -Y2? 3 which is one of the materials of the heating furnace tube related to claim 1, austenitic heat-resistant alloy which is a conventional material and alloy of Fe-20Cr-5 Ai.

Figure 2 is a perspective view of the main part of the heating furnace tube related to claim 2. Figure 3 is a perspective view describing components and the heating furnace tube tensioner related to claim 2. Figure 4 is a cross-sectional side view of the main portion describing the mode of manufacture of the heating furnace tube related to claim 2. Figure 5 is a perspective view of the main portion of the heating furnace tube related to claim 2. Figure 6 is a perspective view describing components and the tensor of the heating furnace tube related to claim 2. Figure 7 is a cross-sectional side view describing the mode of manufacture of the tube of heating furnace related to claim 2. Figure 8 is a side view in cross section of the main portion that describes another embodiment of the heating furnace tube related to claim 2. Figure 9 is a cross-sectional side view of the main portion describing another embodiment of the heating furnace tube related to claim 2; and Figure 10 is a cross-sectional side view of the main portion describing another embodiment of the heating furnace tube related to Figure 2.

BEST MODE FOR CARRYING OUT THE INVENTION Referring now to the drawings, the best mode for carrying out the invention in relation to a heating furnace tube, a method for using the heating furnace tube, and a method for manufacturing the furnace tube are described. heating. In the drawings the same numbers and signs are used for the same components to omit redundant explanations. A heating furnace tube related to the present invention (claim 1) is a heating furnace tube used for fluid flow containing hydrocarbon or carbon monoxide, such as a fractionating tube of an ethylene plant, and is made of ferrous alloy ODS of rare earths using ferrous alloy of highly ferritic chromium with Ai-added as a base, more particularly yttrium ODS ferrous alloy containing 19-26% Cr by weight and 3-6% of Ai by weight. Table 1 shows the result after examining carbonization resistance, high temperature oxidation resistance and mechanical characteristic (high temperature resistance, ductility) for various alloy compositions including yttrium ODS ferrous alloy used for the furnace tube of heating of the present invention (claim 1). The carbonization resistance in the present was judged based on a known carbon precipitation test. In other words, a sample is prepared (4 x 10 x 45 mm) for each alloy whose surface has been finished with emery paper (600 grids) and has been oxidized under steam at 950 ° C, each sample is buried in a solid carburizer, is carburized at 1100 ° C, oxidized in an atmosphere at 1100 ° C, and then carbonization and decarbonization are repeated 10 times, then changes in weight before and after carbonization are checked for each sample, and resistance to carbonization it is judged depending on the degree of change in weight. The carbonization test has been conducted under the following conditions. Gas source: benzene (0.5 g / h), carrier gas: argon (16 Nml / min), added amount of S: 1 ppm or less, temperature: 800 ° C and time: 8 hours. High temperature oxidation resistance, high temperature resistance and ductility are criteria to be judged whenever each alloy material can be used in a practical way for a heating furnace tube considering the state where the furnace tube of heating is placed, that is, the outer surface is required to be heated by an incinerator, high temperature fluids flow through, and sufficient mechanical strength, to be part of a plant.

In table 1, © indicates practically enough, 0 indicates possible,? indicates practically insufficient and * indicates impossible, and in table 1, samples N0.8-N0. 15, that is, the yttrium ODS ferrous alloy containing 19-26% Cr by weight and 3-6% Ai by weight is suitable for a heating furnace tube in terms of resistance to carbonization and other characteristics. Figure 1, on the other hand, shows the comparison result of heat resistant austenitic alloy (high Ni steel, high Cr), Fe-20Cr-5A £ alloy, and Fe-20Cr-5A alloy -Y2O2, which is one of the materials of the heating furnace tube of the present invention for resistance to carbonization, more specifically weight change before and after carbonization. Although the high Cr Ni high steel and the Fe-20Cr-5A alloy are manufactured by casting processes, the Fe-20Cr-5A alloy -Y-YYO3 of the heating furnace tube of the present invention is a dispersion alloy. strengthened manufactured by powder metallurgy. A sample (4 x 10 x 45 mm) is prepared for each alloy whose surface has been finished with emery paper (600 grids) and has been oxidized under a steam at 950 ° C, each sample is buried in a solid carburizer, is Carburized at 1100 ° C, it is oxidized in an atmosphere at 1100 ° C, and then the carbonization and decarbonization are repeated 10 times, then the weight changes before and after the carbonization are checked for each sample.

The carbonization test has been conducted under the following conditions. Gas source: benzene (0.5 g / h), carrier gas: argon (16 Nml / min), added amount of S: 1 ppm or less, temperature: 800 ° C and time: 8 hours. As shown in Figure 1, the change in weight before and after alloy carbonization of the heating furnace tube of the present invention (claim 1) is even less than that of the Fe-20Cr-5A alloy with excellent resistance to carbonization, which makes it clear that the addition of yttrium oxide to the Fe-20Cr-A alloy contributes to a greater improvement in carbonization resistance. A comparison result between samples No. 5 and No. 8 in Table 1 also shows that the addition of yttrium oxide to the Fe-Cr-Ai alloy contributes to a greater improvement in carbonization resistance. Table 1 clearly shows that the ferritic high chromium ferrous alloy containing 19-26% Cr by weight and 3-6% Ai by weight has a relatively good resistance to carbonization, and particularly the ferrous alloy ODS of yttrium. Samples No. 8-No. 15 causes extremely low changes in weight before and after carbonization, approximately 1 mg / cm2, indicating good resistance to carbonization, as seen in the alloy of Fe-20Cr-5A ^ -Y2? 3 in Figure 1 compared to the high Ni steel High Cr and Fe-20Cr-5A alloy 7 Material containing 28% or more Cr by weight and 8% or more Ai by weight is low in ductility, more specifically in elongation break, and material that contains 14% or less of Cr by weight is deficient in oxidation resistance in a high temperature area, therefore both of those materials have problems in practical use as material for heating furnace tubes, and the material where yttrium oxide has not been added is low in resistance at high temperature, therefore it is difficult to apply this material to current heating furnace tubes. The yttrium ODS ferrous alloys of samples No. 8 - No. 15 where yttrium oxide has been added, on the other hand, have better resistance to carbonization and high temperature resistance, and as a result, it has been clear that the Rare earth ODS ferrous alloy containing 19-26% Cr by weight and 3-6% Ai by weight is suitable for the material of heating furnace tubes. The heating furnace tube related to the present invention is made of rare earth ODS ferrous alloy which contains 19-26% Cr by weight and 3-6% Ai by weight, and the method for using the heating furnace tube related to the present invention (claim 8) is to pass hydrocarbon or carbon monoxide through the heating furnace tube made of rare earth ODS ferrous alloy in the composition mentioned above . And because the rare earth ODS ferrous alloy containing 19-26% Cr by weight and 3-6% Ai by weight has extremely good carbonization resistance, as mentioned above, the related heating furnace tube with the present invention (claim 1) and the method for using the heating furnace tube related to the present invention (claim 8) can minimize the carbonization caused by operation of the plant, and the decarbonization range can be extended much longer than conventional types. The extension of the decarbonisation interval in this way improves the productivity of the plant considerably, and the economic effect of the present invention becomes enormous, including a decrease in the cost for decarbonisation, a decrease in thermal fatigue due to shutdowns and restarts. of operation of the plant in decarbonization, and an increase in life. In the case of ethylene plant fractionating pipes, where the temperature of the pipe wall exceeds 1000 ° C, even reaching 1100 ° C in some locations, exact control is required for the operation of the plant with austenitic resistant alloys to heat, because the melting point is only 150 - 200 ° C higher than 1100 ° C, but if rare earth ODS ferrous alloy of the present invention is used which has the melting point of 14080 ° C for heating furnace tubes, security will be further improved, and the operation of the plant will be even simpler. Because the heating furnace tube of the ethylene plant is extremely long, it is advisable to use the heating furnace tube related to the present invention (claim 1) only for locations where carbonization problems occur, using the heating tube. Heating furnace manufactured from conventional materials for other locations, and connecting pipe uses to build an entire heating furnace pipe from an economic standpoint. It is well known that adding S (sulfur) compound to the fluid flowing through the heating furnace tube is effective in controlling carborization. Table 2 shows the result of the examination of the influence of S on the carbonization resistance for ferrous alloy ODS of rare earths of the heating furnace tube of the present invention (claim 1) that is, the ferrous alloy ODS of earths Rare containing 19-26% Cr by weight and 3-6% Ai by weight, and heat-resistant austenitic alloy (25Cr-35Ni steel) of a conventional heating furnace tube. The carbonization test has been conducted under the following conditions. Gas source: 10% methane + hydrogen, additive: DMS (dimethyl sulfide), 0 ppm, 200 ppm (S = 100 ppm in units of atomic weight), temperature 900 ° C, 1000 ° C, 1 100 ° C and time: 5 hours. Table 2 indicates a comparison of carbonization resistance depending on the material, the amount of compound S added, and temperature when the amount of weight change caused by carbonization of ferrous alloy ODS of rare earths when compound of S is added. Under conditions of temperature of 900 ° C and 1000 ° C, the change in weight caused by carbonization is decreased by adding S compound for ferrous alloy of rare earth ODS related to the present invention and austenitic heat resistant alloy which is the material of comparison (conventional material), as shown in table 2. Low temperature condition of 1 100 ° C, on the other hand, the change in weight caused by carbonization is decreased by adding S compound in the case of ferrous alloy ODS of earth Rarely related to the present invention, but the weight change caused by carbonization tends to increase by adding compound of S in the Austenitic heat resistant alloy, which is the comparison material (conventional material). Thus, it is clear that adding 100 ppm of S in units of atomic weight improves the carbonization resistance of rare earth ODS ferrous alloy and austenitic heat resistant alloy under temperature condition of 1000 ° C or less.

In this manner in a heating tube created by connecting the heating furnace tube of the present invention made of ferrous alloy ODS of rare earths, and the heating furnace tube made of austenitic heat-resistant alloy, good resistance to the carbonization by adding 100 ppm or less of S in units of atomic weight to fluid flowing through the tube and using the tube under a temperature condition of 1000 ° C or less and 550 ° C or more where the ferrous alloy ODS of earth Rarely related to the present invention does not cause brittle fractures (at 475 ° C), and as a consequence the heating furnace tube can be used suitably in a hydrocarbon environment where carbonization occurs easily. Adding the amount of S that is added in excess of 100 ppm (in units of atomic weight) is not suitable for industrial purposes because problems related to corrosion occur and problems related to S removal in downstream processes. Add S (sulfur) to fluid flowing through the heating furnace tube, DMS (dimethyl sulfide) and DMDS (dimethyl disulfide) can be used properly and a sufficient effect can also be expected by adding sulfide gas hydrogen. As described above, the cost of the plant can be considerably reduced if the entire heating furnace tube of an ethylene plant is created by connecting the heating furnace tube related to the present invention (claim 1) made of ferrous alloy ODS of Rare earth and the heating furnace tube made of heat resistant austenitic alloy, in other words, using the heating furnace tube made of austenitic heat resistant alloy for part of the whole heating furnace tube. If the fluid containing 100 ppm or less of S in units of atomic weight flows through the heating furnace tube constructed by connecting the heating furnace tube related to the present invention (claim 1) made of rare earth ODS ferrous alloy and a heating furnace tube made of heat-resistant austenitic alloy, using the heating furnace tube on a temperature scale of 550 ° C to 1000 ° C, carbonization on ferrous alloy ODS of rare earth and alloy can be minimized austenitic heat resistant, and therefore the decarbonization interval can be extended much longer than conventional types. The extension of the decarbonisation interval in this way improves the productivity of the plant considerably, and the economic effect of the present invention becomes enormous, including a decrease in costs for decarbonisation, a decrease in thermal fatigue due to shutdowns and restarts of the plant in decarbonization, and an increase in life. Figure 2 to Figure 4 show the heating oven tube (claim 2) created by connecting the heating oven tube related to the present invention (claim 1) and the heating oven tube made of conventional material, and the method for manufacturing the heating oven tube (claim 11). The heating furnace tube 1 shown in Figure 2 is created by joining a heating furnace tube component 10 on a side made of heating furnace tube related to the present invention made of ferrous alloy ODS of rare earth containing 19 - 26% Cr by weight and 3-6% Ai by weight with a heating furnace tube component on the other side 20 made of austenitic heat-resistant alloy, which is bonded through metal insert by bonding by diffusion. The heating furnace tube component on one side 10 and the heating furnace tube component on the other side 20 of the heating furnace tube 1 are joined through short coupling tube 30 made of austenitic heat resistant alloy which is the same material as the heating furnace tube component on the other side 20. For the heating furnace tube component on the other side 20, not only heat-resistant austenitic alloy but also ferrous alloy can be used. ODS of rare earths which is the same material as the heating tube component of heating on one side . For the short coupling tube 30 also, not only the heat-resistant austenitic alloy mentioned above can be used but also ferrous alloy ODS of rare earths which is the same material as the heating furnace tube component on a side 10. Heating furnace tube 1 described above is manufactured by the following procedure. First, the outer surface of the joining side edges of the heating furnace tube component on one side 10 (outer diameter: 70 mm, wall thickness: 5 mm) and the heating furnace tube component on the other side 20 whose size is the same as the heating tube component of heating on one side 10 (outer diameter: 70 mm, wall thickness: 5 mm) are ground on a scale of 30 mm from the edge of the respective tube component to make a surface roughness of 25S. Then Ni-4% B alloy film M used as a metal insert is formed to a thickness of 50 μm by electrolytic deposition on the outer surface of the joining side edge of the heating furnace tube component on one side 10, and on the outer surface of the side joining edge of the heating furnace tube component on the other side 20, which are terminated as mentioned above. For the metal insert, a regular amorphous metal product, such as Bni metal for strong solder welding, can be used.

Then the side joining edge of the heating furnace tube component on one side 10 and the lateral joining edge of the heating furnace tube component on the other side 20 are inserted to each edge of the short coupling tube 30, by 30 mm respectively. Herein, the short coupling tube 30 has an internal diameter of 70 mm, a wall thickness of 8 mm, and a length of 60 mm, and the inner surface 30 has been finished at a surface roughness of 25S. Both ends of the outer surface of the short coupling tube 30 have approximately 10 ° of tapered surfaces 30t and 30t where the diameter decreases towards the edge. It is possible to form the metal insert film not only on the joining side edges of the aforementioned heating oven tube components 10 and 20, but also on the inner surface 30a of the short coupling tube 30 mentioned above, and also it is possible to form the film of the metal insert only on the inner surface of the coupling short tube 30 mentioned above. After inserting the joining side edge of the heating furnace tube component on one side 10 and the lateral joining edge of the heating furnace tube component on the other side 20 to the short coupling tube 30 respectively, the short tube coupling 30 is contacted in the radio direction by the tensioners 40 and 41 adhered to each tapered surface 30t and 30t of the short coupling tube 30, so that the joining side edges of the heating oven tube components 10 and 20 and the surface 30a of the short coupling tube 30 are pressed by sandwiching the layers of plates M and M of the metal insert, and are in contact with pressure for bonding. The tensioners 40 and 41 herein have a ring shape respectively, of which the inner surface has a tapered surface 40t and 411, similar to the tapered surface 30t and 30t of the short coupling tube 30, and the short coupling tube 30. is contacted in the radio direction by moving the tensioners adhered to each tapered surface 30t and 30t of the short coupling tube 30 in the direction in which they approach each other. The pressurizing means P for pressurizing the short coupling tube 30 to the heating furnace tube component on one side 10 and the heating furnace tube component on the other side 20 are made of the tapered faces 30t and 30t of the short coupling tube 30 mentioned above and the tensioners 40 and 41 mentioned above. After joining the heating furnace tube component on one side 10 and the heating furnace tube component on the other side 20 with the short coupling tube 30, the interior of each heating furnace tube component 10 and 20 is subjected to exhaust until the vacuum degree becomes 0.001 Torr or less. 10A and 20A of Figure 4 are barrier plates adhered to the seal openings of the edges of the heating oven tube components 10 and 20 when the inside of each of the heating oven tube components 10 and 20 they are subjected to exhaustion. Exhausting within each of the heating furnace tube components 10 and 20 prevents oxidation of the film M of the metal insert, and allows to check the state of attachment between each of the heating furnace tube components. and 20 and the coupling short tube 30. The connection of each of the heating furnace tube components 10 and 20 through the short coupling tube 30 makes the centering (alignment of the central axis) of the furnace tube component. of heating on one side 10 and the heating furnace tube component on the other easier side 20, and implements air tightness inside and outside each heating tube tube component 10 and 20. It is acceptable to fill inert gas inside of each of the heating furnace tube components 10 and 20 after the exhaust to avoid oxidation of the M film of the metal insert, and it is also acceptable to fill inert gas inside of each of the heating oven tube components 10 and 20 without exhaust.

After exaggeration within each of the heating furnace tube components 10 and 20, a heater H inserted into the above-mentioned heating furnace tube components 10 and 20 increases the temperature by induction of heating to the temperature a wherein the film M of the metal insert melts, and this temperature is maintained for 1 hour so that the union advances by diffusion (union by diffusion of liquid phase). It is also possible to melt the film M of the metal insert and advance the bond by diffusion by infrared heating, instead of using induction heating. When each of the heating furnace tube components 10 and 20 is heated from the inside, each heating furnace tube component 10 and 20 is thermally expanded in the radius direction, which prevents a pressure drop from bonding between each component of heating furnace tube 10 and 20 and the short coupling tube 30 during heating along with the joining force by the pressurization means P mentioned above. After the junction is complete by diffusion holding a high temperature for 1 hour, the heating furnace tube 1 is cooled to room temperature, then the tensioners 40 and 41 are removed from the short coupling tube 30 and the manufacturing process of the heating furnace tube 1 ends.

As shown in Table 2, the completed heating furnace tube 1 has an appearance that the short coupling tube 30 is adhered to the connection part between the heating furnace tube component on one side 10 and the pipe component of the heating pipe. heating furnace on the other side 20. In the case of the heating furnace tube 1 having the aforementioned configuration, the plant cost can be considerably reduced by using the heating furnace tube component on the other side 20 which It is partially manufactured from austenitic heat resistant alloy. If the heating furnace tube 1 having the aforementioned configuration allows fluid to flow containing 100 ppm or less of S in atomic weight units through and is used on a temperature scale of 550 to 1 000 ° C, the carbonization in the heating furnace tube component on one side 10 made of rare earth ODS ferrous alloy and in the other heating furnace tube component on the other side 20 made of austenitic heat resistant alloy can be minimized, and as a consequence the decarbonisation interval can be extended much longer than a conventional heating oven tube, which generates an enormously high economic effect. Needless to say, the heating furnace tube related to the present invention (claims 1 and 2) and the method for using the heating furnace tube related to the present invention (claim 8) can be applied effectively not only to the fractionation tubes of an ethylene plant, but also to several heating furnace tubes that are subject to carbonization problems, such as CCR plant in an oil refining plant. The heating furnace tube related to the present invention (claim 2) of which an objective is to solve the problem of carburization is also manufactured by exactly the same procedure as the heating furnace tube 1 shown in figure 2 to figure 6 As shown in Figures 5 to 7, the heating furnace tube 1 'related to the present invention (claim 2) is created by joining the heating furnace tube component on a side 10' made of YDS ferrous alloy yttrium which it contains 20% Cr by weight and 4.5% Ai by weight, and the heating tube tube component on the other side 20 'made of heat-resistant austenitic alloy (25Cr-35Ni-Fe) by diffusion bonding through of metal insert. The aforementioned heating furnace tube 1 'has a short coupling tube 30' (intermediate member) made of a heat resistant austenitic alloy (25Cr-35Ni-Fe) which is the same material as the furnace tube component of heating on the other side 20 ', and the component 10 'of heating furnace tube on one side and the heating furnace tube component on the other side 20' are joined through the short coupling tube 30 'mentioned above. For the heating furnace tube component on the other side 20 ', not only heat-resistant austenitic alloy tube can be used, such as Hpmod Sumitomo Metal HPM centrifugal casting tube, and Inco Alloy 803 but also ferrous alloy ODS tube which has the same material as the heating furnace tube component on one side 10 '. For the short coupling tube 30 ', not only the austenitic heat-resistant alloy tube mentioned above can be used but also an ODS ferrous alloy tube which has the same material as the heating furnace tube component on one side 10 'and ferritic heat resistant alloy tube. The heating furnace tube 1 'mentioned above is manufactured by the following procedure. First, the outer surface of the side joining edges of the heating furnace tube component on one side 10 '(outer diameter: 70 mm, wall thickness: 5 mm) and the heating furnace tube component on the other side side 20 'whose size is the same as the heating furnace tube component on one side 10' (outer diameter: 70 mm, wall thickness: 5 mm) are ground on a 30 mm scale from the edge of the heating component. respective tube to make a surface roughness of 25S. Then a film M of Ni-4% B alloy used as the metal insert is formed to a thickness of 5 μm by electrolytic deposition on the outer surface of the lateral joining edge of the heating furnace tube component on one side 10 ' and the outer surface of the lateral joining edge of the outer heating furnace tube component on the other side 20 ', which are terminated as mentioned above. For the metal insert, a regular amorphous metal product, such as Bni metal for welding with strong solder can be used. Then the side joining edge of the heating furnace tube component on one side 10 'and the joining side edge of the heating furnace tube component on the other side 20' are inserted at each edge of the short coupling tube 30. 'by 30 mm respectively. Herein the short coupling tube 30 'has an internal diameter of 70 mm, a wall thickness of 8 mm and a length of 60 mm, and the inner surface 30a' has been finished to make a surface roughness of 25S. Both ends of the outer surface of the short coupling tube 30 'have approximately 10 ° of tapered surfaces 30t' and 30f where the diameter decreases towards the edge.

It is possible to form the film of the metal insert not only on the side joining edges of the heating tube components of heating oven O 'and 20' mentioned above, but also on the inner surface 30a 'of the short coupling tube 30'a mentioned above, and it is also possible to form the film of the metal insert only on the inner surface of the short coupling tube 30 'mentioned above. After inserting the joining side edge of the heating furnace tube component on one side 10 'and the joining side edge of the heating furnace tube component on the other end 20' to the short coupling tube 30 'respectively, the short coupling tube 30 'is contacted in the radio direction by the tensioners 40' and 41 'adhered to each tapered surface 30f and 30t' of the short coupling tube 30 ', so that the side edges of the components are joined together of heating furnace tube 10 'and 20' and the inner surface 30a 'of the short coupling tube 30' are pressed by sandwiching the layers of plates M and M of the metal insert, and are in contact with pressure for bonding. The tensioners 40 'and 41' in the present have a ring shape respectively, of which the inner surface has a tapered surface 40t 'and 411' similar to the tapered surfaces 30t 'and 30t' of the short coupling tube 30 'mentioned above , and the short coupling tube 30 'is contacted in the radio direction by moving the tensioners adhered to each tapered surface 30t' and 30t 'of the short coupling tube 30' in the direction in which they approach each other. The pressurizing means P for pressurizing the short coupling tube 30 'to the heating furnace tube component on one side 10' and the heating furnace tube component on the other side 20 'are made of the surfaces 30t 'and 30f of the short coupling tube 30' mentioned above and the tensioners 40 'and 41' mentioned above. After joining the heating furnace tube component on one side 10 'and the heating furnace tube component on the other side 20' with the short coupling tube 30, the inside of each heating furnace tube component 10 'and 20' is subjected to exhaustion until the degree of vacuum becomes 0.001 Torr or less. 10A 'and 20A' in FIG. 7 are barrier plates adhered to the seal openings of the edges of the heating oven tube components 10 'and 20' when the inside of each of the oven tube components of heating 10 'and 20' are subjected to exhaust. Exhausting inside each of the components of the heating furnace tube 10 'and 20' prevents the oxidation of the film M of the metal insert, and makes it possible to check the state of connections between each of the components of the furnace tube of the metal insert. heating 10 'and 20' and short coupling tube 30 '.

Joining each of the heating oven tube components 10 'and 20' by the short coupling tube 30 'makes the centering (alignment of the central axis) of the heating oven tube component on one side 10' and the component of heating furnace tube on the other side 20 'easier and implements air tightness inside and outside each heating tube tube component 10' and 20 '. It is acceptable to fill inert gas within each of the heating furnace tube components 10 'and 20' after exhaust to avoid oxidation of the metal insert film M, and it is also acceptable to fill inert gas within each one of the heating furnace tube components 10 'and 20' without exhaust. After exhausting the inside of each of the heating furnace tube components 10 'and 20' a heater H inserted into the above-mentioned heating furnace tube components 10 'and 20' increases the temperature by induction heating to the temperature at which the film M of the metal insert melts, and this temperature is maintained for one hour so that the connection advances by diffusion (binding by liquid phase diffusion). It is also possible to melt the film M of the metal insert and advance the connection by diffusion by infrared heating, instead of induction heating.

When each of the heating furnace tube components 10 'and 20' is heated from the inside, each heating furnace tube component 10 'and 20' is thermally expanded in the radio direction, which prevents a fall of joining pressure between each heating furnace tube component 10 'and 20' and the short coupling tube during heating together with the assembly force by the aforementioned pressurization means P. After the junction by diffusion is complete holding a high temperature for one hour, the heating furnace tube V is cooled to room temperature, then the tensioners 40 'and 41' are removed from the short coupling tube 30 ', and the The manufacturing process of the heating furnace tube 1 'ends. As shown in Figure 5, the completed heating furnace tube 1 'has an appearance that the short coupling tube on one side 30' is adhered to the connection part between the heating furnace tube component on one side 10 '. and the heating furnace tube component on the other side 20 '. It has been confirmed that the heating furnace tube 1 'manufactured in this manner has practically sufficient efficiency where the joining section can withstand a barometric pressure of 100 during hydraulic testing. In the heating furnace tube 1 'manufactured through the above-mentioned process, at least the heating furnace tube component on the side 10' is made of yttrium ODS ferrous alloy which has good resistance to carburization, so both the replacement interval of heating furnace tube can be extended longer than a conventional heating furnace tube. This has a considerable economic effect because the expense of replacing heating furnace tubes can be decreased, and an extension of the plant shutdown interval due to carburization depth measurement prevents a drop in productivity, and an extension The interval of plant operation stoppages due to carburization depth measurement also decreases the thermal fatigue caused by stopping in furnace operation and restarting operation, which extends the operative life of the plant. The strength of the joining section of each heating furnace tube component 10 'and 20' of the heating furnace tube 1 'is lower than an ODS ferrous alloy tube and a heat-resistant austenitic alloy tube which they are basic materials. The high temperature resistance and resistance to carburization of a heat-resistant austenitic alloy tube, which is used for a part of the heating furnace tube 1 ', is lower than those of an ODS ferrous alloy tube, and It is also known that an ODS ferrous alloy tube also exhibits a brittle phenomenon depending on the operating temperature scale.

As a result, experiments were conducted in terms of structural change and resistance to carburization to confirm the optimal operating temperature scale of the heating furnace tube 1 ', and the following results were obtained.

Union Structural change Resistance to carburization Ferrous alloy brittle at 475 ° C 1200 ° C or less ODS / ferrous alloy ODS Brittle ferrous alloy at 475 ° C 1100 ° C or less ODS / heat-resistant ferritic alloy Ferrous alloy Brittle at 475 ° C 1100 ° C or less ODS / austenitic heat resistant alloy For an evaluation of carburization resistance, a specimen was placed in a quartz tube and heated in an electric furnace where methane and hydrogen gas flowed, then the change in weight of the specimen was measured. As the above results show, the operating temperature scale of the heating furnace tube 1 'should be set at 550 ° C or more where brittle formation does not occur at 475 ° C, and at 1200 ° C or less where the resistance to carburization is sufficient. In other words, using the heating furnace tube 1 'on a temperature scale of 550 ° C to 1200 ° C avoids brittle fractures caused by brittle formation at 475 ° C and implements a sufficient resistance to carburization. In the case of conventional heating furnace tube made of austenitic heat-resistant alloy, on the other hand, considerable carburization occurs on a temperature scale exceeding 1100 ° C. This problem of carburization can be solved by using ODS ferrous alloy tubes for all components of the heating furnace tube located near a temperature environment of 1100 ° C, and using heat-resistant austenitic alloy tubes for pipe components. heating furnace located near an environment of 1000 ° C temperature, as the kiln outlet. In this way, the heating furnace tube and the method of manufacturing the heating furnace tube related to the present invention allow different materials to be used for heating furnace tube components depending on the operating temperature conditions, and especially using a Austenitic heat-resistant alloy tube for a part of the heating furnace tube can decrease plant costs. The heating oven tube 100 in Fig. 8 is fabricated from the heating oven tube component on one side 110 made of an ODS ferrous alloy tube and the heating furnace tube component on the other side 120 made of a heat-resistant austenitic alloy which are joined through metal insert by diffusion bonding. For the heating furnace tube tube component on the other side 120, not only can a heat resistant austenitic alloy tube be used but also an ODS ferrous alloy tube which is the same material as the furnace tube component of heating on one side 110. The film M of the metal insert which is formed on the outer surface of the lateral joining edge of the heating furnace tube component on one side 110 and the lateral joining edge of the furnace tube component of heating on the other side 120 is expanded as to couple with the side joining edge of the heating furnace tube component on one side 110. To manufacture the heating furnace tube 100, the side joining edge of the tube component of heating furnace on one side 110 is coupled with the side joining edge of the heating furnace tube component on the other side 120 first, then is the tensioner 140 of which the inner surface has the tapered surface 140t is adhered to the tapered surface 120t of the heating oven tube component on the other side 120, and a stop block 141 is adhered to the section 120f of the heating furnace tube component on the other side 120 where the diameter increases.

The joining side edge of the heating furnace tube component on the other side 120 is then pressurized to the side joining edge of the heating furnace tube component on one side 110 by sandwiching the M layer of the metal insert plate. , then the joint is advanced by diffusion by exhalation, increasing the temperature, and maintaining the high temperature, in the same way as the manufacturing process of the heating furnace tube 1 'mentioned above, and the tube is cooled to room temperature after the diffusion bond is complete, then the tensioner 140 and the stop block 141 are removed and the manufacturing process of the heating oven tube 100 is terminated. The film M of the metal insert can be formed not only on the heating furnace tube component on one side 110 but also on the inner surface of the heating furnace tube component on the other side 120, and can be formed only on the heating furnace tube component on the other side 120. It goes without saying, that the heating furnace tube 100 with the aforementioned configuration also generates an effect equivalent to the heating furnace tube 1 'mentioned above. In the case of heating mantle tube 100 mentioned above, wherein the heating furnace tube component on one side 110 and the heating furnace tube component on the other side 120 are directly bonded through the metal insert by diffusion bonding, the short coupling tube as the intermediate member used for the heating oven tube 1 'mentioned above is unnecessary. The heating furnace tube 200 in Figure 9 is made of the heating furnace tube component on one side 210 made of an ODS ferrous alloy tube and the heating furnace tube component on the other side 220 made of a heat resistant austenitic alloy which are joined through metal insert by diffusion bonding. For the heating furnace tube component on the other side 220, not only can a heat-resistant austenitic alloy tube be used but also an ODS ferrous alloy tube which is the same material as the furnace tube component of heating on one side 210. A male screw 21 OS is on the side joining edge of the heating oven tube component on one side 210 and a female screw 220S is on the heating oven tube component on the other side 220, and the film M of the metal insert is formed on the outer surface of the lateral joining edge of the heating furnace tube component on one side 210 for the complete bonding surface with the heating furnace tube component on the other 220 side, by electrolytic deposition.

To manufacture the heating oven tube 200, the male screw 21 OS on the heating oven tube component on one side 210 and the female screw 220S on the heating oven tube component on the other side 220 are screwed together for mechanically joining each heating furnace tube component 210 and 220, and the joining side edges of the heating furnace tube components 210 and 220 are pressure contacted by sandwiching the M-plate layer of the metal insert, then advancing junction by diffusion by exhaust, increasing the temperature, and maintaining the high temperature, in the same way as the manufacturing process of the heating furnace tube 1 'mentioned above, after the tube is cooled to room temperature after it is complete the diffusion bonding, and the manufacturing process of the heating furnace tube 200 ends. The film M of the metal insert M can be formed not only on the heating furnace tube component on one side 210 but also on the heating furnace tube component on the other side 220, and can be formed only on the heating oven tube component on the other side 220. The female screw can be on the heating oven tube component on one side 210, and the male screw on the heating oven tube component on the other side 220 A circular insert ring made of metal insert can be adhered to the attachment sections a and b of each of the heating oven tube components 210 and 220. Needless to say, the heating oven tube 200 with the The aforementioned configuration also generates an effect equivalent to the aforementioned heating furnace tube 1 '. In the case of the above-mentioned heating furnace tube 200, wherein the heating furnace tube component on one side 210 and the heating furnace tube component on the other side 220 are directly bonded through metal insert by diffusion bonding, the short coupling tube as the intermediate member used for the heating oven tube 1 'mentioned above is unnecessary. Also in the heating furnace tube 200 mentioned above, mechanical strength and air tightness in a high temperature environment can be implemented by combining mechanical bonding by screws and diffusion bonding. The heating furnace tube 300 in Figure 10 is made of the heating furnace tube component on one side 310 made of an ODS ferrous alloy tube and the heating furnace tube component on the other side 320 made of a Heat-resistant austenitic alloy tube which are joined by means of metal insert by diffusion bonding.

For the heating furnace tube component on the other side 320, not only can a heat-resistant austenitic alloy tube be used, but also an ODS ferrous alloy tube which is the same material as the heating furnace tube component. on one side 310. A coupling section 31 OT of tapered convex shape is on the side joining edge of the heating furnace tube component on one side 310, and a tapered concave coupling section 320T is on the side edge for joining the heating furnace tube component on the other side 320, and the film M of the metal insert is formed on the outer surface of the joining side edge of the heating furnace tube component on one side 310, for all the bonding surface with the heating furnace tube component on the other side 320 by electrolytic deposition. To manufacture the heating furnace tube 300, the convex coupling section 310T on the heating furnace tube component on one side 310 and the concave coupling section 320T on the heating furnace tube component on the other side 320 are coupled to mechanically join each of the heating furnace tube components 310 and 320, and the joining side edges of the heating furnace tube components 310 and 320 are contacted with pressure by sandwiching the plate layer M of the metal insert applying compression stress of 0.1 kg / mm2 or more in the tube axis direction of each heating furnace tube component 310 and 320. Then the diffusion bonding proceeds by exhausting, increasing the temperature and maintaining the temperature in the same way as the tube manufacturing process of heating furnace 1 'mentioned above, after the tube is cooled to room temperature after it is completed the diffusion bonding, and the manufacturing process of the heating furnace tube 300 ends. The film M of the metal insert can be formed not only on the heating furnace tube component on one side 310 but also on the heating furnace tube component on the other side 320, and can be formed only on the component of heating furnace tube on the other side 320. The concave coupling section may be on the heating furnace tube component on one side 310, and the convex coupling section may be on the heating furnace tube component on the other side 320. A circular insert ring made of metal insert may be adhered to the attachment sections a and b of each of the heating tube tube components 310 and 320. Needless to say, the tube of Heating furnace 300 with the aforementioned configuration also generates an effect equivalent to the heating furnace tube 1 'mentioned above.

In the case of the above-mentioned heating furnace tube 300, wherein the heating furnace tube component on one side 310 and the heating furnace tube component on the other side 320 are directly bonded through metal insert by diffusion bonding, the short coupling tube as the intermediate member used for the heating oven tube 1 'mentioned above is unnecessary. Also in the aforementioned heating furnace tube 300 the mechanical strength and air tightness in a high temperature environment can be implemented by combining mechanical bonding by a tapered junction and diffusion bonding. The film M of the metal insert used in each of the aforementioned embodiments is formed by electrolytic deposition, but wet electrolytic deposition, dry electrolytic deposition, non-electrolytic deposition, physical deposition (eg vacuum deposition, sputtering, electrolytic deposition). ion) and electrolytic vapor deposition, including chemical deposition (eg high temperature CVD, plasma CVD), metal coating and paste and other methods can be used to form the metal insert M film. It is also possible to insert metal, specifically tubular or circular insert material made of a thin metal insert plate or metal insert film in the area between the heating furnace tube component on one side and the furnace tube component of heating on the other side. Needless to say, the heating furnace tube related to the present invention (claim 2) and the method of manufacturing the heating furnace tube related to the present invention (claim 11) can be applied effectively not only to the fractionation tubes of an ethylene plant but also to several heating furnace tubes that are subject to carburization problems, such as a CCR plant in a petroleum refining plant.

INDUSTRIAL APPLICABILITY A heating furnace tube, a method for using the heating furnace tube, and a method for making the heating furnace tube related to the present invention can be effectively applied to heating furnace tubes which are subject to problems of carbonization and carburization.

Claims (14)

NOVELTY OF THE INVENTION CLAIMS

1. - A heating furnace tube used to allow fluid containing hydrocarbon or carbon monoxide to flow, characterized in that the heating furnace tube is made of ferrous alloy reinforced by rare earth oxide dispersion containing 17-26% Cr in weight and 2 - 6% of Ai by weight.

2. A heating furnace tube characterized in that a heating furnace tube component made of ferrous alloy reinforced by rare earth oxide dispersion containing 17-26% Cr by weight and 2-6% Ai by weight and another heating furnace tube component made of ferrous alloy reinforced by rare earth oxide dispersion or a heat resistant alloy are joined through metal insert by diffusion bonding.

3. The heating furnace tube according to claim 2, characterized in that the heating furnace tube allows fluid containing 100 ppm or less of S to flow in units of atomic weight, and is used on a temperature scale of 550 ° C-1000 ° C.

4. The heating furnace tube according to claim 2, characterized in that the heating furnace tube consists of a short coupling tube in which a lateral joining edge of one of the heating furnace tube components and a joining side edge of another heating furnace tube component are inserted, and said heating furnace tube component and another heating furnace tube component are joined by short coupling tube making attachment by diffusion in a state wherein the side joining edges of one of the heating furnace tube components and another of the heating furnace tube components and the short coupling tube are contacted under pressure by a pressurizing means, by means of a metal insert arranged between the joining side edges of one of the components of heating furnace pipe and other pipe component No heating and short coupling tube.

5. The heating furnace tube according to claim 4, characterized in that the pressurizing means consists of a tapered surface created on an outer surface of the short coupling tube and a tensioner that engages the tapered surface and contracts the tube. short coupling in a radio direction.

6. The heating furnace tube according to claim 4, characterized in that the metal insert is formed by electrolytic deposition.

7. The heating furnace tube according to claim 2, characterized in that the heating furnace tube is used on a temperature scale of 550 ° C - 1200 ° C.

8. - A method for using a heating furnace tube characterized in that fluid containing hydrocarbon or carbon monoxide flows through the heating furnace tube made of ferrous alloy reinforced by rare earth oxide dispersion containing 17-26% Cr in weight and 2 - 6% of Ai by weight.

9. The method for using the heating furnace tube according to claim 8, characterized in that another heating furnace tube component made of heat resistant alloy is joined by diffusion bonding through a metal insert.

10. The method for using the heating furnace tube according to claim 9, characterized in that the heating furnace tube is used to allow fluid flowing containing 100 ppm or less of S to flow in units of atomic weight, and used on a temperature scale of 550 ° C-1000 ° C.

11. A method for manufacturing a heating furnace tube comprising a heating furnace tube component made of ferrous alloy reinforced by rare earth oxide dispersion containing 17-26% Cr by weight and 2-6% of Ai in weight; and another heating furnace tube component made of the ferrous alloy reinforced by dispersion of rare earth oxide or heat resistant alloy which are bonded through a metal insert by diffusion bonding, characterized in that the method of manufacture of the tube of heating furnace consists of the steps of: forming or inserting the metal insert to at least one of the joining side edges of the heating furnace tube component and another heating furnace tube component; contacting the side joining edges of one of the heating furnace tube components with the joining side edge of another heating furnace tube component directly or through an intermediate member; and diffusion bonding of one of the heating furnace tube components and another of the heated furnace tube components heated the metal insert.

12. The method for manufacturing the heating furnace tube according to claim 11, characterized in that the metal insert is formed by electrolytic deposition.

13. The method for manufacturing the heating furnace tube according to claim 11, characterized in that the intermediate member is a short coupling tube to which the lateral joining edge of one of the heating furnace tube components and the joining side edge of another of the heating furnace tube components are inserted, and a heating furnace tube component and another heating furnace tube component are joined through the coupling tube making diffusion bonding in a state wherein the side joining edges of one of the heating furnace tube components and another heating furnace tube component and the short coupling tube are contacted under pressure by means of a pressurizing means, through a heat insert. metal disposed between the joining side edges of a heating furnace tube component and another heating furnace tube component and the short coupling tube.

14. The method for manufacturing the heating furnace tube according to claim 12, characterized in that the pressurizing means comprises a tapered surface formed on an outer surface of the short coupling tube and a tensioner that engages with the tapered surface and contact the short coupling tube in a radio direction. APPENDIX SHEET SUMMARY OF THE INVENTION A heating furnace tube, a method for using the same and a method for manufacturing same which have been developed with a view to eliminating the inconveniences that occur when flowing a carbon containing fluid into the heating furnace tube; the heating furnace tube consisting of an iron alloy with distributed rare earth oxide particles containing 17-26% by weight of Cr and 2-6% by weight of Al; the method for manufacturing this heating furnace tube consisting of the steps of forming or inserting a metal insert on or into at least one of a joining end portion of a heating furnace tube element and that of the other heating element of heating furnace tube, bringing these two connecting end portions in contact by pressing with each other directly or through an intermediate member, and diffusion-welded the two heating tube elements to each other by heating the insert from - ^ - tt ^ MUtÍÍÉd-MiáM ^ - ^ - ^^ iíillMÁi