JP4613122B2 - Removal method of moving blade of dry furnace top pressure recovery turbine - Google Patents

Description

  The present invention relates to a method for extracting a rotor blade of a dry furnace top pressure recovery turbine from a rotor at the time of disassembly for periodic inspection or the like.

  The top pressure recovery turbine, which is installed in the exhaust gas passage of the blast furnace plant and used for power generation, recovers the pressure energy of the blast furnace gas generated in the blast furnace at the steelworks as electric power and controls the top pressure control of the blast furnace. It is equipment for performing. There are two types of top pressure recovery turbine equipment, wet and dry. The wet top pressure recovery turbine equipment uses a blast furnace gas discharged from the blast furnace to be washed with a wet dust remover and then led to a turbine for driving the generator. It is.

  On the other hand, in the dry-type furnace top pressure recovery turbine equipment, since the blast furnace gas is removed without being washed with water by the dry dust remover, the temperature of the blast furnace gas does not decrease, and the recovered power is 25 to 25% that of the wet type. It is 45% higher, and power can be recovered efficiently. However, in this dry type furnace top pressure recovery turbine equipment, chlorine ions and sulfate ions in the blast furnace gas, which are mostly removed by water washing in the case of a wet type, are sent to the downstream side without being removed. Therefore, it is known that when dew condensation or the like occurs on the downstream side, chlorine ions or sulfate ions dissolve in the dew condensation part and the like to form a strongly acidic atmosphere and cause severe corrosion to surrounding structures and the like.

  In addition, the rotor blades of the furnace top pressure recovery turbine are generally attached to the rotor by inserting and meshing with the rotor blade mounting portion formed in a concave Christmas tree shape, where the blade implantation portion is formed in a convex Christmas tree shape. . For this reason, extremely large stress acts on the blade implantation portion of the Christmas tree-like moving blade, and a crack may occur in the stress concentration portion. In addition to this, in dry-type furnace top pressure recovery turbine equipment, blast furnace gas enters the gap between the blade implantation part of the rotor blade and the blade attachment part of the rotor to form a strongly acidic atmosphere. There is a problem that both sides are severely corroded to further promote the generation of cracks in the blade implantation portion of the rotor blade.

  For this reason, in the conventional dry furnace top pressure recovery turbine, SUS630 stainless steel (precipitation hardening type stainless steel) excellent in corrosion fatigue strength is used in the blast furnace gas atmosphere with respect to the moving blade, and the blade portion has A coating mainly composed of aluminum is performed. In addition, to increase the corrosion resistance by taking a large chord length for the airfoil, and to prevent the blast furnace gas from entering the gap between the blade implantation part of the rotor blade and the blade attachment part of the rotor, When the moving blade is incorporated into the rotor, an epoxy resin varnish is filled in the gap between the blade-implanted portion of the moving blade and the blade mounting portion of the rotor (see, for example, Non-Patent Document 1).

This epoxy resin varnish is not used as a mere filler, but is required to have a high adhesive strength that does not peel even during normal operation when the gas temperature is about 140 ° C. If this varnish peels off during operation, corrosion may occur in the blade implantation portion of the blade, and the fatigue strength of the blade may be significantly reduced.
Ito Takeyuki "Top Furnace Pressure Turbine", Turbomachinery Vol.15, No.4, pages 19-28, Turbomachinery Association, published in April 1987

Thus, in the conventional dry furnace top pressure recovery turbine, in order to prevent the blast furnace gas from entering the gap between the blade implantation portion of the rotor blade and the blade attachment portion of the rotor, when incorporating the rotor blade into the rotor, An epoxy resin varnish is filled in the gap between the blade implantation portion of the rotor blade and the blade mounting portion of the rotor, and this epoxy resin varnish does not peel even during normal operation when the gas temperature is about 140 ° C. Has high adhesive strength.

  On the other hand, in the dry furnace top pressure recovery turbine, there is a problem that cracks occur in the blade implantation portion of the moving blade as described above. Therefore, it is necessary to perform a nondestructive inspection periodically. The blades are removed from the rotor and the blades are used alone. However, due to the strong adhesive force of the varnish that fills the gap between the blade installation part of the rotor blade and the blade attachment part of the rotor, it is not easy to pull out the rotor blade from the rotor. There is a problem that the wing implantation part of the wing is damaged by galling or the like, and the fatigue strength thereafter is remarkably reduced.

  To solve this problem, the blade implantation part of the rotor blade and the blade attachment part of the rotor are partially heated by a burner, and the varnish is peeled off using the thermal expansion difference between the rotor blade and the rotor. Attempts have also been made to make it easier to pull out. However, partial heating with a burner did not allow the varnish to be peeled sufficiently and uniformly, and removal of the rotor blades could not always be facilitated. Further, even when the varnish is appropriately peeled off, there is a problem that damage such as galling occurs due to the newly remaining varnish.

  The present invention has been made to solve such problems, and is a dry furnace top pressure recovery turbine that is assembled by filling an epoxy resin varnish into a gap between a blade implantation portion of a moving blade and a blade mounting portion of a rotor. Therefore, the rotor blade can be easily removed from the rotor at the time of disassembly, so that no damage such as galling that affects the fatigue strength is generated in the blade embedded part of the rotor blade or the blade mounting part of the rotor. Another object of the present invention is to provide a method for extracting a moving blade of a dry furnace top pressure recovery turbine.

  In order to solve the above-mentioned problems, the means employed by the present invention is driven by blast furnace gas supplied from a blast furnace and is made of an epoxy resin system in the gap between the blade implantation part of the moving blade and the blade attachment part of the rotor. In the method of extracting the moving blade of a dry furnace top pressure recovery turbine in which the varnish is filled and incorporated, at the time of disassembly, the blade embedded portion of the moving blade and the blade mounting portion of the rotor are set at a predetermined temperature with the moving blade being incorporated in the rotor. In this case, the blade is pulled out of the rotor after heating for a predetermined time to lower the adhesive strength of the varnish.

  Epoxy resin varnish has the property of carbonizing by heating at a predetermined temperature for a predetermined time. When this carbonization occurs, the adhesive strength of epoxy resin varnish having strong adhesive strength also decreases. Thus, the blade implantation portion of the rotor blade can be easily pulled out from the blade attachment portion of the rotor.

  The predetermined temperature is desirably 200 ° C. or higher and 400 ° C. or lower. Epoxy resin varnish tends to be carbonized when the heating temperature is 200 ° C. or higher, and has a tendency to lower its adhesive strength. On the other hand, when the heating temperature exceeds 400 ° C., there is a risk of material deterioration in the rotor blade material and the rotor material. The predetermined temperature is more preferably 250 ° C. or higher, and most preferably 350 ° C. or higher.

  The predetermined time is desirably at least 10 hours. From the test results described below and the properties of the epoxy resin varnish, it is presumed that the adhesive strength can be reduced to a certain degree by heating for at least 10 hours. The predetermined time includes a temperature raising time after the start of heating. The predetermined time is more preferably 17 hours or more.

The varnish is preferably a mixture of a silicone-modified epoxy resin varnish and a silicone-based epoxy resin curing agent in a mass ratio of 100: 25-100. Epoxy resin varnishes having such components have sufficient adhesive strength at the normal operating temperature of 140 ° C. and have no possibility of peeling, while the adhesive strength is rapidly increased by heating at the predetermined temperature and for a predetermined time. Therefore, it is most suitable as a varnish for filling the gap between the blade-implanted portion of the rotor blade of the dry furnace top pressure recovery turbine and the blade attachment portion of the rotor.

  The method of extracting a moving blade of a dry furnace top pressure recovery turbine according to the present invention is rotationally driven by a blast furnace gas supplied from a blast furnace and has an epoxy resin varnish in a gap between a blade-implanted portion of the moving blade and a blade mounting portion of the rotor. In the method of extracting the moving blades of the dry furnace top pressure recovery turbine, which is filled and packed, the blade-implanted portion of the moving blade and the blade mounting portion of the rotor are heated at a predetermined temperature for a predetermined time with the moving blade being incorporated in the rotor. Since the rotor blades are pulled out from the rotor after reducing the adhesive strength of the varnish, the rotor blades can be easily pulled out of the rotor during disassembly, so that the fatigue strength can be applied to the blade blade mounting part and rotor blade mounting part. There is an excellent effect that no damage such as galling that affects the surface is generated.

BEST MODE FOR CARRYING OUT THE INVENTION A best mode for carrying out a moving blade extraction method for a dry furnace top pressure recovery turbine according to the present invention will be described in detail with reference to FIGS.
1 is a cross-sectional front view showing a dry furnace top pressure recovery turbine, FIG. 2 is a side view showing the moving blade and rotor of FIG. 1, and FIG. 3 shows a blade mounting portion of the moving blade of FIG. FIG. 4 is a plan view showing the rotor with the extraction jig attached, and FIG. 5 is a side view showing the rotor blade and the rotor with the extraction jig attached.

  A dry furnace top pressure recovery turbine 1 shown in FIG. 1 recovers pressure energy of blast furnace gas generated in a blast furnace at an ironworks as electric power and performs top pressure control of the blast furnace. The blast furnace gas discharged from the blast furnace at the steel works is exhausted to the atmosphere through a dust catcher, dry dust remover, etc., and is guided to a furnace top pressure recovery turbine installed in parallel with the exhaust passage to rotate the turbine. The turbine rotates the generator to generate electricity. As in the case of a wet furnace top pressure recovery turbine, the temperature of the blast furnace gas guided to the turbine does not decrease, so that power can be efficiently recovered.

  As shown in FIG. 1, the furnace top pressure recovery turbine 1 includes a two-stage turbine, and a first stage moving blade 3 and a second stage moving blade 4 are attached around the rotor 2. A first-stage stationary blade 5 and a second-stage stationary blade 6 are disposed in front of the first-stage stationary blade 3 and the second-stage stationary blade 4, respectively. The first-stage stationary blade 5 and the second-stage stationary blade 6 are not illustrated at angles. It has a variable mechanism. The variable angle mechanism blows the blast furnace gas taken from the inlet case 7 through the bell mouth 8 onto the rotor blades 3 and 4 at a predetermined inflow angle by the stationary blades 5 and 6, thereby controlling the rotational speed of the turbine and the blast furnace. The furnace top pressure is controlled.

  The rotor 2 is supported by journal bearings 9 and 10 on the front and rear sides thereof and receives thrust generated in the rotor 2 by a thrust bearing 11 at the rear. The front part of the rotor 2 is connected to a generator (not shown), and the generator is rotated to generate power. The material of the rotor 2 is SUS403 stainless steel (low Cr martensitic heat resistant stainless steel), and the material of the rotor blades 3 and 4 is SUS630 stainless steel having excellent corrosion fatigue resistance even in a blast furnace gas atmosphere. (Precipitation hardening type stainless steel) is used. The blades 21 of the rotor blades 3 and 4 are coated with aluminum as a main component.

As shown in FIGS. 2 and 3, the rotor blades 3 and 4 have the blade implantation portions 22 formed in a convex Christmas tree shape, while the blade mounting portions 24 of the rotor 2 have a concave Christmas tree shape corresponding thereto. Formed. When the rotor 2 and the moving blades 3 and 4 are assembled, the blade-implanted portion 22 of the moving blade is inserted and meshed with the blade mounting portion 24 of the rotor 3 from the front and rear directions, and the moving blades 3 and 4 are attached to the rotor 2. A wedge-shaped insertion piece (not shown) is inserted into the gap 27 between the Zabton portion 23 of the rotor blades 3 and 4 and the rotor 2 to give a thrust force to the outer periphery of the rotor blades 3 and 4 in the circumferential direction.

  Further, when the rotor blades 3 and 4 are incorporated into the rotor 2 in order to prevent the blast furnace gas from entering the gap 26 between the blade implanting portion 22 of the rotor blades 3 and 4 and the blade mounting portion 24 of the rotor 2, An epoxy resin varnish is filled in a gap 26 between the wing implanting portions 3 and 4 and the wing mounting portion 24 of the rotor 2. As this varnish material, for example, a material in which a silicone-modified epoxy resin varnish and a silicone-based epoxy resin curing agent are mixed at a mass ratio of 100: 65 is used.

  This varnish material is not used as a mere filler, but is required to have a high adhesive strength that does not peel even during normal operation when the gas temperature is about 140 ° C. If this varnish is peeled off during operation, corrosion will occur in the blade implantation part of the rotor blade, and the fatigue strength of the rotor blade will be significantly reduced. As typical examples from such a viewpoint, for example, silicone-modified epoxy resin varnish: ES1002T having an epoxy equivalent of 555 to 680 manufactured by Shin-Etsu Silicone Co., Ltd. and a silicone-based epoxy resin curing material: KC224 are used. The varnish material is not necessarily limited to this, and other equivalent products can also be used.

  In the dry furnace top pressure recovery turbine facility, chlorine ions and sulfate ions in the blast furnace gas, which are mostly removed by water washing in the case of a wet type, are sent to the downstream side without being removed. Therefore, when dew condensation occurs on the downstream side, chlorine ions or sulfate ions dissolve in the dew condensation portion and the like to form a strongly acidic atmosphere, causing severe corrosion in surrounding structures. However, the filling of the varnish prevents the blast furnace gas from entering the gap between the blade implantation portion 22 of the rotor blades 3 and 4 and the blade mounting portion 24 of the rotor 2, and corrosion of the rotor blades 3 and 4 and the rotor 2 is prevented. Occurrence and reduction of fatigue strength promoted thereby are prevented.

  On the other hand, in the dry furnace top pressure recovery turbine, there is a problem that cracks occur in the blade implantation portions 22 of the rotor blades 3 and 4, and therefore, it is necessary to periodically perform non-destructive inspection and the like. This inspection is carried out in a state where the furnace top pressure recovery turbine 1 is disassembled, the rotor blades 3 and 4 are extracted from the rotor 2, and the rotor blade is a single unit. The extraction operation of the rotor blades 3 and 4 is performed as follows.

  In a state where the rotor blades 3 and 4 are incorporated in the rotor 2, the blade implantation portion 22 of the rotor blades 3 and 4 and the blade mounting portion 24 of the rotor 2 are about 350 ° C. (predetermined temperature) by a high temperature electric furnace, for example. For 24 hours (predetermined time). By this heating, the varnish is carbonized, and the varnish having a strong adhesive force due to the carbonization also decreases its adhesive strength, so that the blade implantation portion 22 of the rotor blades 3 and 4 can be easily removed from the blade mounting portion 24 of the rotor 2. Can be pulled out. Note that the predetermined time includes a temperature raising time until the predetermined temperature is reached. In practice, it is difficult to actually measure whether or not the temperature of the blade implantation portion 22 of the rotor blades 3 and 4 has reached a predetermined temperature. Rather, it is set as a drought time including the temperature rising time. This is because it is more realistic.

  After the heating is completed, natural cooling is performed, and an extraction jig 31 is attached to the blade implantation portion 22 of the rotor 2 and the rotor blades 3 and 4 as shown in FIGS. The extraction jig 31 is screwed from the side into a fixing part 32 for fixing the jig 31 to the rotor 2 and a protruding part 25 between the two blade attachment parts 24 of the rotor 2, and the jig 31 is Two screw portions 33 for fixing to the projecting portion 25 and the tip are screwed into the blade implantation portion 22 of the rotor blades 3 and 4, and the blade implantation portion 22 of the rotor blades 3 and 4 is pulled out hydraulically. It consists of a drawing rod 34.

Hydraulic pressure is applied to the pulling rod 34 to pull out the blade implantation portion 22 of the rotor blades 3 and 4 from the blade mounting portion 24 of the rotor 2. At this time, the varnish filled between the blade implanting portion 22 of the rotor blades 3 and 4 and the blade mounting portion 24 of the rotor 2 is carbonized by the heating, and its adhesive strength is almost zero. The rotor blades 3 and 4 can be easily pulled out from the rotor 2. This is presumably because the carbonized varnish forms a thin and smooth coating layer on the blade implantation portion 22 of the rotor blades 3 and 4 to reduce the frictional resistance when the rotor blades 3 and 4 are extracted.

  Then, at the earliest possible stage, the wedge-shaped insertion piece inserted into the gap 27 between the Zabton portion 23 of the rotor blades 3 and 4 and the rotor 2 is removed. By extracting the rotor blades 3 and 4 from the rotor 2 in this manner, the blade implanting portion 22 of the rotor blades 3 and 4 and the rotor 2 can be compared with the conventional extraction method using the peeling action by partial heating of the burner. The possibility of causing damage such as galling that affects the fatigue strength in the blade mounting portion 24 is extremely low.

  The heating temperature is not limited to the above-mentioned 350 ° C., but is desirably 200 ° C. or more and 400 ° C. or less. From the test results described below, it can be seen that epoxy resin varnish tends to carbonize and lower its adhesive strength when the heating temperature is 200 ° C. or higher, regardless of its type. In particular, the adhesive strength of the varnish is 50% or less at 140 ° C., which is the temperature during normal operation, by heating at 200 ° C.

  On the other hand, when the heating temperature exceeds 400 ° C., there is a risk of material deterioration in the rotor blade material made of SUS630 stainless steel and the rotor material made of SUS403 stainless steel. Therefore, the upper limit temperature may be appropriately set depending on the moving blade material and the rotor material used. The lower limit temperature of the predetermined temperature is more preferably 250 ° C. or higher, and most preferably 350 ° C. or higher.

  This is because the adhesive strength of the varnish is 20% or less at 250 ° C. and 140 ° C., which is the normal temperature, and is several percent or less at 350 ° C. On the other hand, even when heated to 350 ° C, there is a decrease in adhesive strength sufficient to extract the rotor blades, so further consideration is given to the thermal effects on the rotor blade material and rotor material, and more efficient electric furnace work is considered. And the upper limit temperature of the said predetermined temperature can also be 350 degrees C or less.

  The heating time (predetermined time) is not necessarily limited to the above-mentioned 24 hours. In consideration of workability of the actual heating work, etc., it is set to 24 hours here. However, if this heating time is at least 10 hours including at least the temperature rising time after the start of heating, the varnish is subjected to constant carbonization. It is estimated that the adhesive strength of the varnish can be weakened. If the heating time is set to 17 hours or longer, the adhesive strength of the varnish can be more reliably reduced.

  On the other hand, although depending on the size of the rotor or the like, the temperature of the blade implantation part 22 of the rotor blades 3 and 4 reaches the predetermined temperature approximately several hours after the start of heating. In addition, as described above, if the heating temperature exceeds 400 ° C, the blade material and the rotor material may be deteriorated. Therefore, the heating time should be as short as possible within a range where carbonization and deterioration of the varnish can be obtained. It is also necessary. From this viewpoint and the test results described later, the heating time can be set to a maximum of 24 hours.

  Furthermore, the varnish used was a mixture of a silicone-modified epoxy resin varnish and a silicone-based epoxy resin curing agent in a mass ratio of 100: 65, but the mixing ratio is not necessarily limited to this, If it is mixed at a mass ratio of 100: 25 to 100, it is considered that the same performance as above can be obtained.

  In addition, the moving blade extraction method of the dry furnace top pressure recovery turbine described above is only an example, and various modifications are possible based on the gist of the present invention, and they are not excluded from the scope of the present invention.

With regard to epoxy resin varnish filled from the viewpoint of corrosion prevention between the blade implantation part of the rotor blade of the furnace top pressure recovery turbine and the rotor blade mounting part, the adhesive strength decreases due to heating and the ease of extraction In order to verify this, the following two types of tests were conducted.
(1) Tensile test using plate specimens [Test conditions]
A plate-shaped test piece was manufactured, and three types of epoxy resin-based varnish were heated at 140 ° C., which is the temperature during normal operation of the dry furnace top pressure recovery turbine, for 24 hours and after natural cooling, and 250 The adhesive strength after 24 hours of heating at 0 ° C. and natural cooling was verified by measuring the average tensile force. The three types of varnish used are as follows.

A varnish: Silicone-modified epoxy resin varnish with epoxy equivalent of 555-680 and silica
A corn-based epoxy resin curing agent mixed at a mass ratio of 100: 65
B varnish: Epoxy resin paint (trade name: Neo Goose # 200) and polyamide resin epoxy
A xy resin curing agent mixed in a mass ratio of 4: 1 C varnish: epoxy resin having an epoxy equivalent of 184 to 194 and polyamide resin epoxy
A resin curing agent mixed at a mass ratio of 7: 3 [test result]
The test result of the tensile strength about said AC varnish is shown in FIG. From this, the following was found.

  The average tensile force after heating for 24 hours at 140 ° C, which is the temperature during normal operation of the dry furnace top pressure recovery turbine, and after natural cooling, C varnish is about 3.5 times the A varnish, B varnish is A It was the smallest, about 0.6 times the varnish. In addition, the average tensile force after heating at 250 ° C for 24 hours and after natural cooling decreases to about 1/4 of the varnish when heated to 140 ° C, and B varnish to about ½ when heated to 140 ° C. C varnish was reduced to about ¼ when heated at 140 ° C.

[Conclusion]
For any of the above-mentioned epoxy resin varnishes A to C, the average tensile force decreases to about 1/2 to 1/4 by heating at 250 ° C. for 24 hours, and it becomes clear that the adhesive strength is reduced by heating. It was. However, for B varnish, the average tensile force after heating at 140 ° C, which is the temperature during normal operation of the dry furnace top pressure recovery turbine, is the lowest, and the decrease in adhesive strength after heating at 250 ° C is the most. It was small.

(2) Sampling test using actual moving blades Based on the test results of the plate test piece described above, sufficient adhesive strength can be secured at 140 ° C, which is the temperature during normal operation of the dry furnace top pressure recovery turbine, and A pull-out test using an actual moving blade was performed on the epoxy resin varnishes A and C from the viewpoint that the decrease in adhesive strength due to heating was large.

〔Test conditions〕
Test varnish: Epoxy resin varnish of A and C above Used moving blade: Actual moving blade with wing implantation part length of 200 mm (SUS630 stainless steel)
Rotor used: Test block with wing attachment length of 220 mm (SUS403 stainless steel
)
Heating time: After drying at room temperature for 4 days after filling with varnish Heating temperature: 140 ° C, a plate-shaped test piece that is the temperature during normal operation of the dry furnace top pressure recovery turbine
In the test of 250 ° C., a clear decrease in adhesive strength due to heating was observed,
Close to the upper limit temperature of 400 ° C that does not cause material deterioration in the rotor blade material and rotor material 3
3 types of temperature at 50 ° C

Heating method: High-temperature electric furnace Heating time: 50 ° C / hour during heating, heating time is 24 hours including this heating time Extraction jig: Actual machine blade extraction jig (see Figs. 4 and 5)
Measurement time: After natural cooling after heating Measurement temperature: normal temperature Measurement method: Measure the two types of pressure, the hydraulic pressure at the beginning of the moving blade and the hydraulic pressure at the moving of the moving blade
However, due to restrictions on the strength of the jig, the maximum extraction pressure is 400 kg / c.
m ² g.
〔Test results〕
The pull-out test results for the A varnish and C varnish are shown in FIG. From this, the following was found. However, when the drawing hydraulic pressure is shown as 400 kg / cm ² g in FIG. 7, it indicates that the moving blade could not actually be pulled out by the hydraulic pressure.

  Similar to the test results of the above plate-shaped test pieces, both the A varnish and the C varnish have sufficient adhesive strength that does not cause peeling when heated at 140 ° C., which is the temperature during normal operation of the dry furnace top pressure recovery turbine. Have. In addition, when heated at 250 ° C, the pressure at the time of movement and the start of movement of the A varnish is reduced to 20% or less at the time of heating at 140 ° C, which is the temperature during normal operation, and the movement of the C varnish. The initial pressure drops below 50% during heating at 140 ° C.

At the time of heating at 350 ° C., the pressure at the time of movement and the start of movement of the A varnish was 1 kg / cm ² g or less so that it could be easily pulled out by hand. As for the C varnish, the pressure at the time of movement decreased to the same level as that of the A varnish, while the pressure at the start of movement only decreased to the same level as when heated at 250 ° C.
[Conclusion]
Any epoxy resin varnish of the above A and C varnishes has sufficient adhesive strength during normal operation, while the A varnish is far superior to C varnish in reducing the adhesive strength by heating. The A varnish was heated to 350 ° C. so that it could be pulled out by hand.

  Moreover, in any of the A and C varnishes, a considerable decrease in the adhesive strength was observed when heated at 250 ° C., and in particular, the A varnish had little trouble in extraction. From this test result and the general properties of the epoxy resin varnish, it is considered that a certain decrease in adhesive strength can be obtained even by heating at about 200 ° C.

  Further, the heating time was all set to 24 hours mainly considering the workability of the actual heating work, etc., but if heating is performed for at least 10 hours, preferably at least 17 hours including the temperature rising time, A It is estimated that a certain decrease in adhesive strength can be obtained with any of the varnishes C and C.

It is a section front view showing a dry type furnace top pressure recovery turbine. It is a side view which shows the moving blade and rotor of FIG. It is a perspective view which shows the blade slot part of the moving blade of FIG. It is a top view which shows the rotor of the state which attached the extraction jig | tool. It is a side view which shows the moving blade and rotor of the state which attached the extraction jig | tool. It is a bar graph which shows the tension test result by a plate-shaped test piece. It is a line graph which shows the sampling test result using a real machine blade.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Furnace top pressure recovery turbine 2 Rotor 3 1st stage moving blade 4 2nd stage moving blade 5 1st stage stationary blade 6 2nd stage stationary blade 7 Inlet case 8 Bellmouth 9, 10 Journal bearing 11 Thrust bearing 21 Blade part 22 Blade implantation part 23 Zabton part 24 Wing attachment part 25 Projection part 26, 27 Gap 31 Extraction jig 32 Fixing part 33 Screw part 34 Extraction rod

Claims (2)

The epoxy resin varnish is filled in the gap between the blade implantation part (22) of the rotor blade (3, 4) and the blade mounting part (24) of the rotor (2) while being rotationally driven by blast furnace gas supplied from the blast furnace. In the method of extracting a moving blade of a dry furnace top pressure recovery turbine (1) to be incorporated, the varnish is prepared by mixing a silicone-modified epoxy resin varnish and a silicone-based epoxy resin curing agent in a mass ratio of 100: 25 to 100. In addition, at the time of disassembly, the blade implantation portion of the moving blade and the blade attachment portion of the rotor are heated at 200 ° C. or more and 400 ° C. or less by a high-temperature electric furnace in a state where the blade is incorporated in the rotor. A method of extracting a moving blade of a dry furnace top pressure recovery turbine, wherein the moving blade is pulled out from the rotor after heating for a predetermined time to lower the adhesive strength of the varnish. The predetermined time is, blades extraction method of dry furnace top pressure recovery turbine according to claim 1, characterized in that at least 10 hours or more.