JPH0510692A - Sealing structure for gas preheating device - Google Patents

Abstract

PURPOSE:To obtain a sealing structure for a gas preheating device, which can effectively prevent wear due to sliding and corrosion due to thermal waste gas, hold excellent sealing performance for a long period and lower levels of sliding sound and unpleasant sound. CONSTITUTION:A sealing member 3 formed of inorganic glass and/or wear resistant ceramics, is engaged with an extraction preventing member 4, and a flat sliding surface 3a is exposed. A guide rod 6 is inserted into a guide hole 5b of a solid lubricant molded form 5, and the form 5 is pressed longitudinally of the rod 6 through a flat plate 9 by a coil spring 8. Thus, the flat sliding surface 5a of the form 5 is slid to the sliding surface 19a of a sealing bar. A weight or a leaf spring may be used instead of the spring 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal structure for a gas preheater.

[0002]

2. Description of the Related Art An air preheater is a thermal power generation boiler, a ship boiler, and other chemical equipment such as oil making, distillation, and reforming furnaces that recover heat from exhaust gas by heat exchange into combustion air to improve thermal efficiency. Is used to raise the.
FIG. 9 is a schematic perspective view of the air preheater.

A rotor 11 is rotatably housed in a rotor housing 17, and two radial sealing plates 13 are provided on the side surface of the rotor 11 for each rotor side surface. The rotor housing 17 is supported by a pedestal (not shown), and the rotor 11 is rotated by a drive device (not shown) as indicated by arrow H.

Thermal waste gas is circulated on the upper side of the rotor 11 as indicated by an arrow D, and air is circulated on the lower side as a counter flow as indicated by an arrow F. The exhaust gas layer and the air layer are blocked by the radial sealing plate 13. A heating element is accommodated in the rotor 11, and the heating element absorbs heat from the heat exhaust gas D. Then, when the rotor 11 rotates, the cold air is heated when passing through the heating element, and the hot air is sent to the boiler or the like as indicated by an arrow G. On the other hand, since heat is absorbed from the hot exhaust gas, the cold exhaust gas is discharged to the outside air as shown by arrow E.

In such an air preheater, the rotor 11
There are gaps between the outer peripheral portion of the rotor and the rotor housing 17, and between the side surface of the rotor 11 and the radial sealing plate 13, and exhaust gas and air leak from these gaps, which lowers the thermal efficiency. Therefore, it is important to make these gaps as small as possible to enhance the sealing effect.

[0006]

As a method of sealing the gap between the outer peripheral portion of the rotor and the housing, structural sealing is performed by making the gap as small as possible.

The temperature of the exhaust gas is 300 to 400 ° C. and the temperature of the air is from room temperature to 100 ° C. The rotor containing the heating element is deformed in response to such temperature change.
With structural seals, expansion due to such temperature changes,
Alternatively, the settling will increase the gap and reduce the sealing effect.

As a method of sealing the gap between the rotor side surface and the radial sealing plate, 12 or
The structural sealing is performed by making the gap between the diaphragm plate divided into 24 pieces and the radial sealing plate made of metal as small as possible.

In such a method, the sealing effect is limited, and when the structural material is corroded by the exhaust gas component, the gap becomes large, and the sealing effect is lowered.
It is expected that the sealing effect will be improved if the gap between the sealing members is eliminated and the members are slid under pressure.

In addition to the above-mentioned structural sealing problem, in the rotary air preheater for boiler combustion used in thermal power plants, etc., the fuel used in the boiler is coal, heavy oil, etc. There is a problem that corrosive gases such as ionic oxides and nitrogen oxides are contained in the air, and dew condensation occurs at a low temperature portion of the air preheater, and each component of the air preheater is easily corroded. In addition, there is a problem that dust in the heat exhaust gas adheres to each component such as the heating element of the air preheater and deteriorates the heat exchange characteristics of the air preheater. Washing with water is carried out. On this occasion,
Boilers of thermal power plants, etc. are operated continuously for a long period of time, and the boiler rest period is extremely short.Therefore, the above-mentioned deposits can be washed off with water while the air preheater is not sufficiently cooled at about 200 ° C. There is. Therefore, there is a problem that the air preheater parts are subjected to severe thermal shock. Furthermore, the rotary air preheater for boiler combustion used in thermal power plants is a large device with a rotor diameter of 1 to 20 m, and the parts used for the preheater are large. 100 ×
A 50 mm seal member is used. Therefore, the heat shock conditions for the seal member due to the above-mentioned hot water washing are extremely severe.

A sliding member used in a rotary air preheater for boiler combustion in a thermal power plant or the like is required to have excellent wear resistance, corrosion resistance and thermal shock resistance.
Conventionally, SS steel or corrosion-resistant steel was used as the material for the seal member, but it is still unsatisfactory as a sliding member because of its insufficient wear resistance and corrosion resistance, requiring frequent maintenance. It was

In order to solve this problem, the present applicant has disclosed a seal member made of inorganic glass and wear-resistant ceramics in the specification of Japanese Patent Application No. 1-184449 (filed on July 19, 1989). This seal member is preferably pressed and slid on a sealing bar, for example, whereby the sealing effect can be most effectively exhibited.

However, as a result of further study by the present inventor, it was found that a problem still remains. That is, a large amount of solid components such as coal ash are contained in the exhaust gas that burns coal or the like, and the solid components have a property of adhering to the surface of the seal member and causing wear. For this reason, even wear-resistant ceramics are worn when pressed and slid for a long period of time, and the sliding sound generated when the sealing member is pressed and slid is very loud and uncomfortable. It turned out to deteriorate the work environment.

An object of the present invention is to effectively prevent corrosion due to heat exhaust gas, maintain good sealing performance for a long period of time, and further reduce wear of inorganic glass and wear-resistant ceramics. It is an object of the present invention to provide a seal structure for a gas preheater that can reduce the amount of sliding noise and reduce unpleasant and offensive noise.

[0015]

SUMMARY OF THE INVENTION The present invention relates to a gas preheater seal structure for sealing a gap between a rotor outer peripheral portion of a gas preheater and a housing or a side face of the rotor and a radial sealing plate. , Inorganic glass and /
Alternatively, a seal member at least a part of which is formed of wear-resistant ceramics, a solid lubricant molded body with a guide hole that is pressed against a sliding surface on which the seal member slides, and inserted into the guide hole And a biasing member for pressing the solid lubricant compact against the sliding surface by biasing the solid lubricant compact in the length direction of the guide member. The present invention relates to a seal structure of a gas preheater.

[0016]

First, an outline of an air preheater (an example of a gas preheater) to which the seal structure of the present invention should be applied will be described.

FIG. 4 is a schematic side view of the air preheater, and FIG. 5 is a schematic front view of the same. A rotor 11 held by a rotating shaft 14 is housed in a housing 17. The rotor 11 is divided into 12 or 24 pieces by a diaphragm plate 12, and a heating element 15 is installed therein. The housing is separated into an exhaust gas tank and an air tank. When the rotor rotates, the heat amount of the exhaust gas is stored in the heating element in the exhaust gas tank, and the air is heated in the air tank. Exhaust gas is, for example, 350 ° C, air is 60
At ℃, passing through the air preheater, the exhaust gas is cooled to 140 ℃ and the air is heated to 300 ℃. Air is pressurized and flows into the boiler, but the pressure difference between air and exhaust gas is, for example, 2500 mm.
It is about aq. Therefore, when the air passes through the air preheater, some leakage occurs in the exhaust gas tank due to the pressure difference.

The leakage path is partly on the side of the rotor, the diaphragm plate 12 and the radial sealing plate 13.
Happens through the gap in. Secondly, it occurs at the outer periphery of the rotor 11 through the gap between the axial sealing plate 16 and the housing 17. Further, the exhaust gas and the air held in the gaps between the heating elements flow into the air tank and the exhaust gas tank, respectively, by the rotation of the rotor, and leak.

The seal structure is devised to minimize such leakage. A method for sealing by making the distance between the diaphragm plate 12 and the radial sealing plate 13 as small as possible is called a radial seal B. A method of sealing by minimizing the distance between the housing 17 and the axial sealing plate 16 installed on the outer circumference of the rotor is called an axial seal A. Further, in order to prevent exhaust gas and air from flowing into the gap between the rotor outer circumference and the housing, a seal structure 18 is installed on the side surface of the rotor outer circumference,
The method of sealing by making the space between the sealing bar 19 attached to 17 and the sealing bar 19 as small as possible is called a bypass seal C.

Of the three seal portions of the radial seal B, the axial seal A and the bypass seal C, the seal structure of the present invention is applied to at least one seal portion. That is, the “seal of the gap between the outer peripheral portion of the rotor of the gas preheater and the housing” corresponds to the axial seal A and the bypass seal C. The “seal of the gap between the side surface of the rotor and the radial sealing plate” corresponds to the radial seal B.

First, an example in which the present invention is applied to the bypass seal C will be described. FIG. 6 is a schematic diagram showing the vicinity of the outer circumference of the rotor of the air preheater. In this example, the present invention is applied to the sealing between the outer peripheral edge of the rotor 11 and the rotor housing.

That is, in the upper bypass seal portion in FIG. 6, the holder 21 is fixed to the sealing bar 19,
The seal structure 1 is held in a holder 21. At this time, the seal structure 1 can be slightly moved up and down in the holder 21, and the sliding surface of the seal structure 1 abuts against the rotor tire 20 by its own weight and slides. There is a slight gap between the seal structure 1 and the sealing bar 19. With such a structure, when the rotor 11 expands and contracts due to heat, the seal structure 1 follows the deformation of the rotor 11.

In the lower bypass sealing portion in FIG. 6, the holder 21 is fixed to the rotor tire 20, and the seal structure 1 is held in the holder 21. The seal structure 1 can be slightly moved up and down in the holder 21, and the sliding surface of the seal structure 1 abuts on the sealing bar 19 by its own weight and slides.

Incidentally, in such a vertical axis type air preheater,
The self-weight of the seal structure 1 presses the seal structure 1 against the sealing bar 19 or the rotor tire 20. On the other hand, in the case of the horizontal axis type air preheater, the self-weight of the seal structure 1 cannot be used, and therefore the seal structure 1 must be biased toward the mating member by a leaf spring, a coil spring, or the like. I have to.

Next, the structure of the preferable seal structure 1 will be described with reference to FIG. Preferably, a substantially rectangular parallelepiped hollow frame body 2 is formed of corrosion-resistant steel, and each vertex of the frame body 2 is provided with R (R). This frame 2
Among them, a plurality of holes (3 in this example) 2a, 2b are formed in the longitudinal direction on the side facing the sealing bar. Of these, in this example, inside the two holes 2a on the end side,
The slip-out preventing member 4 is fixed by welding or the like, and the slender seal member 3 having a trapezoidal cross section is fitted into the slip-out preventing member 4. Of the sealing member 3, a flat sliding surface 3a to be slid with respect to the sliding surface 19a of the sealing bar is exposed, and the other portions are substantially covered with the frame body 2 and the slip-off preventing member 4. Not exposed.

A guide plate portion 2d extending toward the inside of the frame 2 is formed in the hole 2b, and the rectangular parallelepiped solid lubricant molded body 5 is accommodated along the guide plate portion 2d. Seal member 3
The solid lubricating member molded body 5 is pressed against the sliding surface 19a on which the sliding bar slides, and the sliding surface 5a slides on the sealing bar.

The solid lubricant molded body 5 is provided with, for example, a circular through hole as a guide hole 5b, and the guide rod 6 is inserted into the guide hole 5b. The tip of the guide rod 6 should not touch the sliding surface of the sealing bar, the rotor tire, or the like. A male screw 6a is provided at the base of the guide rod 6, and the male screw 6a is inserted into the through hole 2c of the frame body 2.
A nut 7 is fitted to 6a, and thereby the guide rod 6 is fixed to the frame body 2. At this time, the nut 7 can be welded to the frame body 2 to prevent the nut 7 from loosening. Further, the guide rod 6 may be directly welded to the frame body 2 without using a nut or the like.

A coil spring 8 is installed around the guide rod 6. One end of the coil spring 8 is brought into contact with the inner wall surface of the frame body 2, and the other end is brought into contact with the flat plate 9. The flat plate 9 is provided with, for example, a circular through hole as a guide hole 9a, and the guide rod 6 is inserted into the guide hole 9a. The solid lubricant compact 5 is in contact with the flat plate 9 and is pressed against the sliding surface 19a by the coil spring 8 via the flat plate 9. As a result, the solid lubricant compact 5 can be urged in the length direction of the guide rod 6 to press the compact 5 against the sliding surface 19a.

The entire seal member 3 is formed of wear-resistant ceramics or inorganic glass, and the portion of the seal member 3 buried inside the frame 2 is formed of corrosion-resistant steel.
A thin inorganic glass layer may be provided by enamel or glass lining on the side that contacts the sealing bar.

Examples of ceramics having high wear resistance include silicon nitride, silicon carbide, alumina, mullite, sialon, zirconia, and porcelain containing alumina.
These are higher in hardness and superior in wear resistance than metals. Also, in the exhaust gas of the air preheater, sulfur oxide,
Nitrogen oxide and the like are contained, and these react with water to generate sulfuric acid, sulfurous acid, nitric acid, nitrous acid, and the like, but the above wear-resistant ceramics are also stable to these.

As the inorganic glass and the glass lining,
So-called acid-resistant enamel is preferable, and examples of the enamel equipment for the chemical industry referred to in JIS are classified into two types. 1st type: Glass lining A main component of silicic acid (55% or more), boric acid (0 to 10%), and alkali (10 to 20%). 2 types: Acid-resistant boro roe Silicic acid (40% or more), boric acid (0 to 10%), and alkali (10 to 30%) as main components.

Of the above wear-resistant ceramics, alumina and zirconia have a large coefficient of thermal expansion and poor thermal shock resistance. Therefore, in this respect, ceramics having a coefficient of thermal expansion of 70 × 10 ⁻⁷ / ° C. or less, such as porcelain, mullite, silicon nitride,
It is more preferable to use silicon carbide or sialon.

According to this embodiment, since the seal member 3 and the sealing bar are slid under pressure, the effect of the wear-resistant ceramics or the inorganic glass is great, and deformation, wear, corrosion, etc. of the seal member 3 are prevented. It is possible to further improve the thermal efficiency by preventing a gap from being generated at all times without generating the gap.

Since the solid lubricant molded body 5 constantly supplies the solid lubricant to the sliding surface 19a of the sealing bar,
The coefficient of friction between the seal member 3 and the sliding surface of the sealing bar can be reduced, wear of the seal member 3 can be reduced, and the life can be further extended. In addition, it is possible to reduce the level of noise and the level of unpleasant sound that accompany the sliding of the high hardness seal member 3 and the sealing bar.

Therefore, according to such a seal structure, the sealing effect is high, and the life of the seal member is long,
For example, the efficiency of air preheating for thermal power generation, a boiler for ships, etc. can be increased, and when applied to chemical equipment such as oil production, distillation, reforming furnace, etc., the efficiency of heat recovery becomes high. Further, the safety during use is increased and the frequency of maintenance can be reduced. Moreover, the noise and unpleasant noise associated with the sliding of the seal member during operation can be reduced, and the working environment can be improved.

In addition, since the guide rod 6 guides the solid lubricant compact 5 while the coil spring 8 urges and presses the compact 5, the solid lubricant compact 5 has a length equal to that of the guide rod 6. It can be easily replaced by pulling it out in the direction. Further, since the structure for urging the molded body 5 has a small number of parts, it is hard to break down, maintenance is easy, and manufacturing cost can be reduced.

Further, the periphery of the solid lubricant compact 5 is not completely surrounded by the corrosion resistant steel, and the contact length between the compact 5 and the guide plate portion 2d is relatively short. Therefore, even if the solid component such as coal ash is clogged between the molded body 5 and the guide plate portion 2d, it is extruded as the molded body 5 moves, or escapes toward the inner space of the frame body 2. Therefore, the solid component does not adhere to the periphery of the molded body 5 and hinders the operation of the molded body 5, and the molded body 5 can be constantly pressed against the sliding surface 19a.

Further, since the coil spring 8 is used as the biasing means of the molded body 5, as in the case where the seal structure of the present invention is applied to a horizontal axis type air preheater, for example,
Even when the solid lubricant compact 5 has to be pressed in the horizontal direction, the compact 5 can be effectively pressed against the sliding surface 19a. The same applies when the seal structure of the present invention is applied to the vertical axis type air preheater and the molded body 5 must be biased in the opposite direction to gravity.

Further, since the width of the flat plate 9 is larger than the space between the guide plate portions 2d, the flat plate 9 is locked by the guide plate portion 2d even when the solid lubricant compact 5 is consumed or lost. Therefore, there is no possibility that the coil spring 8 will abut and slide.

Examples of the material used for the coil spring 8 include a heat-resistant alloy such as Inconel under the trade name that can maintain the spring property even at a high temperature of 350 to 400 ° C. Moreover, by increasing the natural length of the coil spring and decreasing the spring constant, it is possible to reduce the fluctuation of the load with respect to the fluctuation of the length of the spring, and to press the solid lubricant molded body 5 with a stable force. You can

The solid lubricant used in the solid lubricant compact 5 includes nitrogen boron (BN), graphite (C), molybdenum disulfide (MoS ₂ ), fluorinated graphite (CF) _n , and tungsten disulfide (WS). ), Teflon (TFP, TFEP, TEEP) and the like.

In the seal structure 1 shown in FIG. 1, since the seal member 3 is entirely surrounded by the anti-corrosion steel except for the sliding surface 3a, it is more stable against thermal shock generated by washing with water or the like. .. In this case, wear-resistant ceramics (for example, alumina) having a coefficient of thermal expansion larger than 70 × 10 ⁻⁷ / ° C. can also be applied. At this time, the highest wear resistance is obtained when the content of the alumina component in the alumina ceramics is 96% by weight or more. Examples of the material of the frame body 2 include stainless steel, Inconel, nickel and the like.

A thin plate made of wear-resistant ceramics is incorporated into or fixed to the sliding surface of the sealing bar to form a ceramics guide on which the sealing member should press and slide, thereby effectively wearing the sealing bar. Can be prevented. Of course, the sliding surface of the sealing bar may be acid-proof enamel or glass lining.

In the case of a bypass seal for a vertical axis type air preheater and the sliding surface 9a is vertically below the seal structure, as shown in the enlarged sectional view of FIG. A weight 10 can be used as a biasing means for the molded body 5.

The weight 10 has a rectangular parallelepiped shape, for example, a circular through hole is provided as the guide hole 10a, and the guide rod 6 is inserted into the guide hole 10a. Weight
10 applies a load to the solid lubricant compact 5, and the compact 5 is pressed against the sliding surface by a constant pressure mainly by this load.

Also in this embodiment, the same effect as that of the embodiment of FIG. 1 can be obtained. In addition, the width of the weight 10 is
Since the interval is larger than 2d, even if the solid lubricant molded body 5 disappears, the weight 10 is locked by the guide plate portion 2d, so that the weight 10 does not come into contact with the sliding surface.

FIG. 3 is a sectional view showing a seal structure 41 using a leaf spring as a biasing means instead of the coil spring. The same reference numerals are given to the same functional members as those in FIG. 1, and the description thereof will be omitted.

The leaf spring 42 is formed by processing an elongated flat metal into a V-shaped cross section. Circular through holes 42a and 42c are formed at both ends of the leaf spring 42, respectively.
The guide rod 6 is inserted through 42c. The end portion of the leaf spring on the side of the circular through hole 42a is locked by the bolt 7 and fixed to the frame body 2. The end 42b of the leaf spring 42 on the side of the circular through hole 42c is in contact with the solid lubricant molded body 5. A force is applied between the pair of end portions of the leaf spring 42 in a direction of expanding the bending angle of the leaf spring, which presses the molded body 5 toward the sliding surface 19a and urges it. To be done.

Next, an example in which the present invention is applied to the axial seal A (see FIG. 4) will be described. In FIG. 7, an accommodating portion 24 made of a corrosion-resistant metal having a U-shaped cross section is fixed to the outer periphery of the rotor 11 rotating in the direction of arrow J by welding or the like, and the accommodating portion 24 has a substantially flat plate shape inside. The seal member 23 is stored and fixed. Sliding surface 23 of seal member 23
a slides with respect to the housing 17 in the region where the radial sealing plate 13 is present. The material of the seal member 23 is the same as that of the seal member 3 (see FIG. 1) described above, and the entire member can be molded with wear-resistant ceramics or inorganic glass, and the glass lining is formed only on the sliding surface 23a side. Or enamel may be applied.

Further, a housing portion 27 made of a corrosion-resistant metal having a U-shaped cross section is fixed to the outer periphery of the rotor 11 by welding or the like. A guide rod 26 extending in the radial direction of the rotor 11 is fixed inside the storage portion 27. The solid lubricant compact 25 having a substantially rectangular parallelepiped shape has, for example, a circular through hole as a guide hole.
25b, and the guide rod 26 is inserted into the guide hole 25b. A coil spring 28 is installed around the guide rod 26. One end of the coil spring 28 abuts on the inner surface of the housing portion 27 and the other end abuts on the surface of the solid lubricant compact 25. The solid lubricant compact 25 is guided in the length direction of the guide rod 26 (radial direction of the rotor 11).

A sliding surface 25a is formed on the upper end of the solid lubricant compact 25.
To form a smooth curved surface. Also, on the inner wall surface (sliding surface) 17b side of the housing 17, the curved surface portion 17a
To form. When the rotor 11 rotates in the direction of arrow J, the curved sliding surface 25a first contacts the curved surface portion 17a, and
With the rotation of 11, the molded body 25 is pressed toward the rotor 11, and the coil spring 28 is compressed. Then, the sliding surface 25a is biased and pressed toward the sliding surface 17b of the housing 17. As a result, the sliding surface 17b of the housing 17
A solid lubricant is thinly and uniformly applied to the sliding surface 23a of the sealing member 23 and then slides against the sliding surface 17b of the housing.

Also in this embodiment, the solid lubricant compact 25 is used.
The same effect as described above can be obtained by the combination of the seal member 23 and the seal member 23. Further, the coil 25 is biased to move the molded body 25 to the sliding surface 17b of the housing.
Can be pressed easily and effectively. Furthermore, since the curved surface portions 25a and 17a are provided, the impact when the molded body 25 collides with the housing 17 is dispersed, and the coil spring
It can be converted into a force that compresses and deforms 28.

In the example of FIG. 7, the seal member 23 and the solid lubricant molded body 25 are attached to different members, but they can be attached to the same member as shown in FIG. In addition, FIG.
In this example, wear-resistant ceramics and a glass lining layer are installed on the inner surface of the housing, and seal members facing each other are provided.
It is also effective to prevent abrasion of the metal constituting the housing by sliding it against 23.

Next, a simulation test was conducted to reduce the sliding noise and improve the wear resistance of the seal member mainly by the solid lubricant. A sliding test was performed by the ring-on-disk method, and a sound level meter (NA23 manufactured by Thon) was installed at a position 5 cm away from the sliding portion, and the sliding sound was measured. The sliding sound intensity was defined as the value obtained by subtracting the non-sliding sound volume (noise from devices, etc.) from the sliding sound volume. The frequency of sliding noise was analyzed, and the presence or absence of vibration during sliding, the specific wear amount of the ring, and the friction coefficient were also measured.

An outline of the contact stress fatigue fracture tester used in this test is shown in FIG. The lower sample plate holding jig 34 is pushed upward by the hydraulic pressure of the piston, so that the sample plate
A load is applied between 33 and ring 36. By rotating the upper ring holding jig 32 fixed to the rotating shaft 31 as shown by an arrow K, the sample plate 33 and the ring 36 are rotated.
Rubbing and abrading. These are located in the electric furnace 30,
It can be set to any ambient temperature. Sample plate by friction force
Rotational torque is generated in 33, transmitted to the piston 37, and the torque lever 35 attached to the piston 37 pushes the load cell 38. Load between sample plate 33 and ring 36 is Wkgf, load cell
If the value converted from the output from 38 into a load is Tkgf and the average radius of the ring 36 is Rcm, the friction coefficient μ is μ = TR / 10
It can be calculated as W.

On the other hand, in the sample plate 33 after the test, the depth of the wear groove is measured with a surface roughness meter, and the worn volume is calculated by multiplying the contact area of the ring 36. The wear volume of the ring 36 is also calculated from the height reduction. Wear volume is M, load is P, sliding distance (ring rotation speed x test time x
If x is the average circumference of the ring, the specific wear amount Ws is Ws
= M / Px. The test conditions were as close as possible to the actual machine, but due to the performance of the device, it was not possible to make the load low, and the load was 10 times that of the actual machine. When the wear was too small to measure, the sliding speed was increased and an acceleration test was conducted.

Three kinds of sample plates were prepared. A: All formed of alumina. In FIG.
This corresponds to the case where the sealing bar contact surface side of the seal structure 1 is made entirely of alumina. B: Of the contact area of the ring that contacts the surface of the sample plate, 15% was alumina and the remainder was SUS 430. This corresponds to the case where the solid lubricant molded body 5 does not exist in FIG. 1 and the surface of that portion is SUS 430. C: Of the contact area of the ring that contacts the surface of the sample plate, 15% is graphite, 15% is alumina, and 70% is
Configured to be SUS 430. This corresponds to the example of FIG.

The characteristic values measured for each of the samples A, B and C are shown below. Sample A B C Sliding sound intensity 14 dB 10 dB 4 dB Maximum intensity frequency 8 kHz 8 kHz 1 kHz Sliding vibration Yes No No Specific wear amount 0.1mm ² / N 12mm ² / N 5.2mm ² / N Friction coefficient 0.8 0.9 0.4

As is clear from the above results, according to the seal structure using the solid lubricant molded body, the effect of lubrication is remarkable, and low noise, low unpleasant noise, high wear resistance and low friction are obtained. We were able to achieve significant improvement in performance at the same time. In addition, the working environment can be improved, the life of the seal structure can be extended, the number of times of maintenance of the air preheater can be significantly reduced, and the cost can be greatly reduced. Especially, by using solid lubricant, the main component frequency of sliding noise is 8 kHz.
It changes from a jarring squealing sound of z to a screaming sound of 1kHz, and can significantly reduce the noise level not only in volume but also in hearing.

[0060]

According to the seal structure of the gas preheater of the present invention, at least a part of the seal member is formed of inorganic glass and / or wear resistant ceramics.
Corrosion due to thermal waste gas can be effectively prevented, wear resistance is improved, and good sealing performance can be maintained for a long time.

Further, since the solid lubricant molded body is pressed against the surface on which the seal member slides, the solid lubricant is constantly supplied to the surface on which the seal member slides. The friction coefficient with the moving surface can be reduced, the wear of the seal member can be reduced, and the life can be further extended. Moreover, it is possible to reduce the level of noise and unpleasant noise associated with the sliding of the high hardness seal member. Therefore, it is possible to reduce noise and unpleasant noise associated with the sliding of the seal member during operation, and improve the working environment.

Moreover, since the guide member is inserted into the guide hole of the solid lubricant molded body, and the molded body is biased while being guided and pressed against the sliding surface, the solid lubricant molded body is The guide member can be easily replaced by pulling it out in the longitudinal direction, and the structure for urging the molded body is hard to break down, maintenance is easy, and manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a seal structure.

FIG. 2 is a sectional view of an essential part of a seal structure using a weight 10.

FIG. 3 is a cross-sectional view showing a seal structure using a leaf spring 42 as a biasing means.

FIG. 4 is a schematic side view showing the entire air preheater.

FIG. 5 is a schematic front view showing the entire air preheater.

FIG. 6 is a schematic diagram showing the vicinity of the outer circumference of the rotor of the air preheater.

FIG. 7 is a schematic cross-sectional view showing a state in which a seal member and a solid lubricant molded body are attached to the outer peripheral surface of the rotor.

FIG. 8 is a schematic perspective view showing a contact stress fatigue fracture tester.

FIG. 9 is a perspective view schematically showing the configuration of the entire air preheater.

[Explanation of symbols]

 1 Seal structure 2 Frame 3, 23 Seal member 3a, 23a Sliding surface of seal member 5, 25 Solid lubricant molded body 5a, 25a Sliding surface of molded body 5b, 25b Guide hole 6, 26 Guide rod (guide Example of member) 8, 28 Coil spring (Example of biasing member) 9 Flat plate 10 Weight (Example of biasing member) 11 Rotor 13 Radial sealing plate 17 Housing 17b Housing sliding surface 19 Sealing bar 19a Sealing bar Sliding surface 20 Rotor tire 21 Holder A Axial seal B Radial seal C Bypass seal

Claims (1)

Claim: What is claimed is: 1. A seal structure of a gas preheater for sealing a gap between an outer peripheral portion of a rotor of a gas preheater and a housing or a gap between a side surface of the rotor and a radial sealing plate, comprising: A seal member, at least a part of which is made of glass and / or wear-resistant ceramics,
A solid lubricant molded body with a guide hole that is pressed against a sliding surface on which this seal member slides, a guide member that is inserted into the guide hole, and the solid lubricant molded body A seal structure for a gas preheater, comprising a biasing member for pressing the solid lubricant compact against the sliding surface by biasing in the length direction.