CN218596514U - Device for improving steam oxidation resistance of small-caliber boiler tube of coal-fired boiler - Google Patents

Abstract

The utility model relates to a coal fired boiler technical field provides an improve coal fired boiler small-bore boiler pipe anti steam oxidation's device, includes at least: the sand blasting device comprises a hollow motor, a first nozzle and a sand pipe; the hollow motor is connected with the first nozzle and is suitable for driving the first nozzle to rotate so as to enable sand in the cavity of the first nozzle to be sprayed out through the strip-shaped opening on the surface of the first nozzle; the one end of sand material pipe is passed hollow motor and is stretched into in the cavity of first nozzle, and the other end is suitable for and communicates with outside sand material source: the spraying device is suitable for coating the boiler pipe subjected to sand blasting cleaning with paint; the screen type integral heating, curing and sintering device is suitable for sintering the boiler pipe coated with the coating so as to form an antioxidant coating on the inner pipe wall of the boiler pipe. The device forms the anti-oxidation coating on the inner pipe wall of the boiler pipe, and can greatly improve the steam oxidation resistance of the small-caliber boiler pipe of the in-service coal-fired boiler.

Description

Device for improving steam oxidation resistance of small-caliber boiler tube of coal-fired boiler

Technical Field

The utility model relates to a coal fired boiler technical field, concretely relates to improve anti steam oxidation's of coal fired boiler small-bore boiler pipe device.

Background

The problems of oxidation and corrosion of the surface of the heat exchanger tube at the high-temperature section of the boiler troubles the safe operation of a thermal power generating unit for a long time, the specific gravity of the tube blocking and tube explosion accidents caused by the problems is large in the unplanned shutdown of the unit, and the problems of oxidation and corrosion of the heat exchanger tube of the boiler under higher steam parameters are more severe along with the development of the advanced supercritical thermal power technology at the temperature of 630-700 ℃. Aiming at the characteristics and the using environment of a heat exchanger tube of a boiler of a thermal power generating unit, a coating material capable of thoroughly solving the problem of oxidation corrosion of the heat exchanger tube and a corresponding preparation process are developed at present, however, the most critical link of the preparation process is that the heat exchanger tube needs to be correspondingly heat treated to obtain an effective high-temperature oxidation corrosion resistant coating structure.

The boiler heat exchanger in the prior art is formed by welding single small-diameter boiler tubes, if heat treatment is carried out on the boiler tubes, all the pipelines need to be detached and cut into single tubes to be carried out one by adopting a traditional heat treatment mode, the cost is high, the efficiency is low, the pipelines after heat treatment are required to be welded, assembled and installed again, a large number of welding seams and defects leave a huge period for the heat exchanger tubes to be used again, the problem of oxide skin on the steam side of a thermal power unit is a main potential safety hazard causing accidents such as pipe blockage and pipe explosion of a boiler, and data shows that the number of the oxide skin peeled off from the steam pipeline on the heating surface of the 600MW ultra-supercritical boiler is measured by tons, and the oxide skin can not only block an over/reheater to cause pipe explosion accidents, but also can be carried out of the boiler by high-flow-speed steam to damage turbine blades. In an ultra-supercritical thermal power generating unit, the parts with the largest protection requirement are mainly small-caliber boiler tubes for transmitting high-temperature and high-pressure steam, the using amount is large, and the design life is generally not less than 20 years. Such as: the inner diameter of the boiler tube of the 1000MW unit pass/reheater is 20-50 mm, the length is 8-12 m, the number of tube panel elbows is large, and the using amount reaches more than 1000 tons. With the development of advanced 630-700 ℃ ultra-supercritical fossil power technology in the near future, the problem of oxide skin under higher steam parameters becomes more and more severe.

The technologies of grain refinement, inner wall shot blasting, high Cr alloying and the like can lead the austenitic steel to rapidly grow Cr required by oxidation resistance ₂ O ₃ Film, but Cr ₂ O ₃ The stability in steam above 600 ℃ is poor and the problem of oxide film loosening caused by volatile products in the oxygen-treated unit is more serious. Along with the increase of service time, when the Cr content required by the growth of an oxide film cannot be supplemented, the oxidation resistance of the alloy is also sharply reduced; 25% by weight of Cr-based austenitic steel is excellent in oxidation/corrosion resistance, but poor structure stability lowers the high-temperature permanent strength of the alloy. The martensite heat-resistant steel pipe also faces the same problem in the high temperature region, 9 percent of Cr system martensite heat-resistant steel can reach 200 mu m in thickness of surface oxide skin after being exposed for 1000h in pure water steam at 650 ℃ under normal pressure, and the outer layer is loose and porous Fe ₃ O ₄ The layer is easy to fall off, so that the reliability of safe operation of the 600 ℃ ultra-supercritical thermal power generating unit is greatly reduced. Therefore, how to improve the steam oxidation resistance of the small-caliber boiler tube of the coal-fired boiler on the basis of the existing material selection has important significance.

SUMMERY OF THE UTILITY MODEL

Therefore, the to-be-solved technical problem of the utility model lies in how on the basis of current material selection, improve the anti steam oxidation ability of coal fired boiler small-bore boiler pipe to provide an improve the anti steam oxidation's of coal fired boiler small-bore boiler pipe device.

In order to solve the technical problem, the technical scheme of the utility model as follows:

an apparatus for improving the resistance of small-caliber boiler tubes of a coal-fired boiler to steam oxidation, comprising at least: the sand blasting device is suitable for removing oxide skin growing on the inner wall of each boiler tube in the service tube panel; the sand blasting device comprises a hollow motor, a first nozzle and a sand pipe; the hollow motor is connected with the first nozzle and is suitable for driving the first nozzle to rotate so as to enable sand in the cavity of the first nozzle to be sprayed out through the strip-shaped opening on the surface of the first nozzle; the one end of sand material pipe is passed hollow motor stretches into in the cavity of first nozzle, the other end be suitable for with outside sand material source intercommunication: the spraying device is suitable for coating the boiler pipe subjected to sand blasting cleaning with paint; the screen type integral heating, curing and sintering device is suitable for sintering the boiler pipe coated with the coating so as to form an antioxidant coating on the inner pipe wall of the boiler pipe.

Furthermore, sand blasting unit still includes the haulage rope, the one end of haulage rope with hollow motor keeps away from the one end of first nozzle links to each other, and the other end is suitable for and links to each other with outside draw gear to make outside draw gear pass through the haulage rope drive sand blasting unit removes in the boiler pipe.

Further, the outer wall of the hollow motor and/or the first nozzle is sleeved with an annular sealing ring, and the outer diameter of the annular sealing ring is consistent with the inner diameter of a boiler pipe.

Further, the spraying device comprises a driving mechanism and a spraying mechanism which are connected, the driving mechanism is suitable for driving the spraying mechanism to move in the boiler pipe, and the spraying mechanism is suitable for spraying the coating on the inner wall of the boiler pipe.

Further, the driving mechanism comprises a first shell, a driving wheel and a power battery; a plurality of driving wheels are arranged on the outer wall of the first shell at intervals along the circumferential direction of the first shell, and each driving wheel can move in a telescopic manner along the radial direction of the first shell; the power battery is arranged in the first shell, is electrically connected with each driving wheel and is suitable for driving the driving wheels to rotate.

Further, the spraying mechanism comprises a second shell, a second nozzle, a pneumatic motor, an air path pipe and a feeding pipe; the second shell is connected with the first shell, and the second nozzle is arranged at one end of the second shell, which is far away from the first shell; the pneumatic motor is arranged in the second shell, an air outlet of the pneumatic motor is communicated with an air inlet of the second nozzle, and an air inlet of the pneumatic motor is communicated with an external air source through an air path pipe; one end of the feeding pipe is communicated with the feeding hole of the second nozzle, and the other end of the feeding pipe is communicated with an external coating source.

Furthermore, a plurality of positioning wheels are arranged on the outer wall of the second shell at intervals along the circumferential direction of the second shell, and each positioning wheel can stretch and move along the radial direction of the second shell.

Furthermore, the spraying device also comprises a front camera, a rear camera and a thickness measuring sensor which are suitable for monitoring the spraying process; the front camera is arranged at one end of the second shell, which is far away from the first shell; the rear camera is arranged at one end of the first shell, which is far away from the second shell; the thickness measuring sensor is arranged at one end, far away from the first shell, of the second shell.

Furthermore, the screen type integral heating, curing and sintering device comprises an air-cooled induction heating coil, a coil moving track, a crawler, an intelligent control cabinet and an induction coil power supply; one end of the coil moving track is suitable for being arranged on a boiler ceiling, and the other end of the coil moving track vertically extends downwards and exceeds the bottom of the boiler pipe; the creeper is arranged on the inner side of the coil moving track, and the air-cooled induction heating coil is connected with the creeper; the induction coil power supply is electrically connected with the air-cooled induction heating coil; the intelligent control cabinet is electrically connected with the crawler, and the intelligent control cabinet controls the crawler to drive the air-cooling induction heating coil to move along the coil moving track so as to sinter boiler tubes in the air-cooling induction heating coil.

Furthermore, the screen type integral heating, curing and sintering device also comprises a first stopper and a second stopper; the first limiting stopper and the second limiting stopper are arranged on the coil moving track at intervals so as to limit the operation starting point and the operation end point of the crawler on the coil moving track.

The utility model discloses technical scheme has following advantage:

the utility model provides an improve anti steam oxidation's of small-bore boiler pipe of coal fired boiler device is provided with sand blasting unit, and hollow motor can drive first nozzle and rotate, and the sand material that holds in the cavity of first nozzle is spout from the bar opening to get rid of the cinder that the inner wall of every boiler pipe grows in the pipe panel of being active service: coating the boiler pipe cleaned by sand blasting with paint by a spraying device; and finally, the boiler tube coated with the coating can be sintered through a screen type integral heating curing sintering device so as to form an anti-oxidation coating on the inner tube wall of the boiler tube, and the steam oxidation resistance of the small-diameter boiler tube of the in-service coal-fired boiler can be greatly improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic view of the overall structure of an apparatus for improving the steam oxidation resistance of small-caliber boiler tubes of a coal-fired boiler according to an embodiment of the present invention;

FIG. 2 is a schematic view of the blasting apparatus of FIG. 1;

FIG. 3 is a cross-sectional view of FIG. 2;

FIG. 4 is a schematic view of the spray coating device of FIG. 1;

FIG. 5 is an enlarged schematic view of the drive wheel of FIG. 4;

FIG. 6 is an enlarged view of the positioning wheel of FIG. 4;

FIG. 7 is a schematic view of the screen-type integral heat curing sintering apparatus of FIG. 1;

FIG. 8 is a front view of the crawler of FIG. 7;

FIG. 9 is a top view of the crawler of FIG. 7;

FIG. 10 is a side view of the crawler of FIG. 7;

FIG. 11 is a schematic view of the screen-type integral thermosetting sintering apparatus of FIG. 7 in an operating state.

Description of reference numerals:

10. a ceiling cutting surface; 11. an inlet header; 12. an outlet header; 13. cutting the lower elbow; 14. a tube panel; 15. a boiler ceiling; 21. an induction coil power supply; 22. a coil moving track; 23. a crawler; 24. air-cooling the induction heating coil; 25. an intelligent control cabinet; 31. a sand blasting device; 32. a sand storage tank; 33. a sand material pipe; 41. a spraying device; 42. a paint storage tank; 43. a feed pipe; 44. an air passage pipe;

221. a rail clamp groove; 222. a rail slide bead; 231. a first stopper; 232. a second stopper; 233. a coil fixing bolt; 234. a first wire inlet hole; 235. a second wire inlet hole; 236. a drive motor; 237. a boss;

311. a hollow motor; 312. a first nozzle; 313. a first connecting body; 314. an annular seal ring; 315. a strip-shaped opening; 316. a hauling rope; 317. a wire; 321. a first interface; 3131. a first coupling; 3211. fastening a nut;

411. a drive mechanism; 412. a spraying mechanism; 413. a drive wheel; 414. a first housing; 415. a rear camera; 416. a second connector; 417. positioning wheels; 418. a second nozzle; 419. a pneumatic motor; 420. a front camera; 421. a second housing; 422. a second coupling; 423. a thickness measuring sensor; 4131. a first wheel; 4132. a direct current motor; 4133. a hydraulic telescopic rod; 4134. a hydraulic tank; 4135. a power battery; 4171. a second wheel; 4172. a slide bar; 4173. a sliding cavity; 4174. a compression spring; 4175. a separator.

Detailed Description

The technical solutions of the present invention will be described more clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Furthermore, the technical features mentioned in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.

FIG. 1 is a schematic view of the overall structure of an apparatus for improving the steam oxidation resistance of small-caliber boiler tubes of a coal-fired boiler according to an embodiment of the present invention; as shown in fig. 1, in the present embodiment, when the boiler tube panels are cut at the ceiling, the position of the ceiling cutting surface 10 and the position of the lower elbow cutting surface 13 are as shown in fig. 1, so that the boiler tube panels 14 are separated from the inlet header 11 and the outlet header 12, cut and separated at the lowest part of the lower elbows of the boiler tube panels 14, and the cut boiler tube panels 14 are suspended and fixed by using the in-furnace suspension device.

In this embodiment, the induction coil power supply 21, the sand storage tank 32 and the coating storage tank 42 are disposed on the boiler ceiling 15, and the sand storage tank 32 is connected to the blasting device 31 through the sand pipe 33. The paint storage tank 42 may be in communication with the spray coating device 41 via a feed pipe 43.

Both the blasting device 31 and the spraying device 41 in this embodiment can be fed into the pipeline from the upper cut of the boiler tube panel 14.

As shown in fig. 1, the present embodiment provides an apparatus for improving the steam oxidation resistance of small-caliber boiler tubes of a coal-fired boiler, at least comprising: a sand blasting device 31 adapted to remove scale growing on the inner wall of each boiler tube in service tube panel 14: the spraying device 41 is suitable for coating the boiler pipe subjected to sand blasting cleaning with paint; the screen type integral heating, curing and sintering device is suitable for sintering the boiler tube coated with the coating so as to form an antioxidant coating on the inner tube wall of the boiler tube.

The device for improving the steam oxidation resistance of the small-caliber boiler tubes of the coal-fired boiler, provided by the embodiment, can remove the oxide skin growing on the inner wall of each boiler tube in the service tube panel 14 through the sand blasting device 31: coating the boiler pipe cleaned by sand blasting with paint by a spraying device 41; and finally, the boiler tube coated with the coating can be sintered through a screen type integral heating curing sintering device so as to form an anti-oxidation coating on the inner tube wall of the boiler tube, and the steam oxidation resistance of the small-diameter boiler tube of the in-service coal-fired boiler can be greatly improved.

FIG. 2 is a schematic view of the blasting apparatus of FIG. 1; FIG. 3 is a cross-sectional view of FIG. 2; as shown in fig. 2 and 3, the blasting device 31 includes a hollow motor 311, a first nozzle 312, and a sand pipe 33; the hollow motor 311 is connected with the first nozzle 312 and is suitable for driving the first nozzle 312 to rotate so that the sand in the cavity of the first nozzle 312 is sprayed out through the strip-shaped opening 315 on the surface of the first nozzle 312; one end of the sand pipe 33 passes through the hollow motor 311 and extends into the cavity of the first nozzle 312, and the other end is adapted to communicate with an external sand source.

The sand blasting device 31 further comprises a pulling rope 316, one end of the pulling rope 316 is connected with one end of the hollow motor 311 far away from the first nozzle 312, and the other end of the pulling rope 316 is suitable for being connected with an external pulling device, so that the external pulling device drives the sand blasting device 31 to move in the boiler pipe through the pulling rope 316.

Wherein, the outer wall of the hollow motor 311 and/or the first nozzle 312 is sleeved with an annular sealing ring 314, and the outer diameter of the annular sealing ring 314 is consistent with the inner diameter of the boiler tube.

Specifically, the hollow motor 311 is located at the rear section of the entire blasting device 31, and is connected to an external power source through a lead 317, and is connected to an external pulling device through a pulling rope 316. The first nozzle 312 is installed at the front section of the blasting device 31, and is coaxially connected in series with the hollow motor 311 through the first connecting body 313 and the first coupling 3131, and the axes of the two parts are kept consistent after the connection. The sand pipe 33 passes through the hollow motor 311 and the first nozzle 312, the axial position of the sand pipe 33 is fixed by the fastening nut 3211, and the tail of the sand pipe 33 can be provided with a first connector 321 and connected with the external sand storage tank 32.

The hollow motor 311 may be powered by dc, and the lead 317 is connected to an external power source. The first coupling 3131 is installed inside the hollow motor 311 and is used for connecting the hollow motor 311 with the first nozzle 312, the hollow motor 311 rotates to drive the first nozzle 312 to rotate at a high speed, and the idle rotation speed of the hollow motor 311 is greater than 30000 rpm. The head of the first nozzle 312 may be a conical structure, the conical surface is provided with a plurality of strip-shaped openings 315, and the centrifugal force generated by the high-speed rotation of the first nozzle 312 sprays sand from the strip-shaped openings 315 onto the inner wall of the boiler tube. The connection section of the first nozzle 312 and the hollow motor 311 may be a cylindrical hollow shell, and on the one hand, may be coaxially connected with the hollow motor 311; on the other hand, the hollow structure of the first nozzle 312 may store a small amount of sand in the cavity, and may ensure a continuous blasting operation even in the case where the supply of the sand is unstable. The outer sides of the hollow motor 311 and the first nozzle 312 are respectively provided with an annular sealing ring 314 with the same diameter, and the annular sealing rings 314 are tightly attached to the inner wall of the boiler pipe by adjusting the diameter of the annular sealing rings 314, so that the whole sand blasting device 31 is always positioned in the center of the pipeline in the advancing process.

Wherein, in order to ensure the quality of sandblast clearance, this sand blasting unit 31 adopts the mode work of backing up the spraying in the use. Before the sand blasting operation, the diameter of the annular seal 314 is adjusted, the sand blasting device 31 is arranged in the inner cavity of the boiler pipe to be subjected to sand blasting, and the sand blasting device 31 is made to advance to the foremost end of the boiler pipe to be subjected to sand blasting. After the external sand storage tank 32, the traction device and the power supply for supplying power to the hollow motor 311 are connected, the operation speed of the external traction device is controlled to adjust the sand blasting operation speed. The sand used by the sand blasting device 31 can be various sand blasting materials such as corundum sand, quartz sand and the like, and the granularity of the sand blasting materials is smaller than 500 meshes.

FIG. 4 is a schematic view of the spray device of FIG. 1; FIG. 5 is an enlarged schematic view of the drive wheel of FIG. 4; FIG. 6 is an enlarged view of the positioning wheel of FIG. 4; as shown in fig. 4, 5 and 6, the spraying device 41 includes a driving mechanism 411 and a spraying mechanism 412 connected, wherein the driving mechanism 411 is adapted to drive the spraying mechanism 412 to move in the boiler tube, and the spraying mechanism 412 is adapted to spray the coating material on the inner wall of the boiler tube.

Wherein, the driving mechanism 411 comprises a first housing 414, a driving wheel 413 and a power battery 4135; a plurality of driving wheels 413 are arranged on the outer wall of the first shell 414 at intervals along the circumferential direction of the first shell 414, and each driving wheel 413 can move in a telescopic manner along the radial direction of the first shell 414; a power battery 4135 is disposed within the first housing 414 and is electrically connected to each of the drive wheels 413 and is adapted to drive the drive wheels 413 in rotation.

The spraying mechanism 412 includes a second housing 421, a second nozzle 418, an air motor 419, an air passage pipe 44, and a feeding pipe 43; the second shell 421 is connected to the first shell 414, and the second nozzle 418 is arranged at one end of the second shell 421 away from the first shell 414; the pneumatic motor 419 is arranged in the second shell 421, an air outlet of the pneumatic motor 419 is communicated with an air inlet of the second nozzle 418, and an air inlet of the pneumatic motor 419 is communicated with an external air source through the air path pipe 44; the feed tube 43 has one end communicating with the feed opening of the second nozzle 418 and the other end communicating with an external coating source.

A plurality of positioning wheels 417 are arranged at intervals on the outer wall of the second housing 421 along the circumferential direction of the second housing 421, and each positioning wheel 417 can move in a telescopic manner along the radial direction of the second housing 421.

Wherein, the spraying device 41 further comprises a front camera 420, a rear camera 415 and a thickness measuring sensor 423 which are suitable for monitoring the spraying process; the front camera 420 is arranged at one end of the second shell 421 away from the first shell 414; the rear camera 415 is arranged at one end of the first shell 414 far away from the second shell 421; the thickness measuring sensor 423 is disposed at an end of the second housing 421 away from the first housing 414.

Specifically, the spraying device 41 is mainly composed of a driving mechanism 411 and a spraying mechanism 412, and the arrow is the rear end direction of the spraying device 41. A drive mechanism 411 is located at the rear end of the spray coating device 41 for providing forward and reverse power, the drive mechanism 411 having a first housing 414, four criss-cross drive wheels 413 mounted on the first housing 414, and a power battery 4135 within the first housing 414.

The spraying mechanism 412 is installed at the front end of the spraying device 41, and is used for spraying the coating on the inner wall of the boiler pipe, and the spraying mechanism 412 has a second casing 421, four positioning wheels 417 installed on the second casing 421 and distributed in a crisscross manner, an air motor 419 arranged in the second casing 421, a second nozzle 418 arranged outside the second casing 421, and a front camera 420, a rear camera 415 and a thickness measuring sensor 423 which are used for monitoring the spraying process.

The driving mechanism 411 and the spraying mechanism 412 of the spraying device 41 may be connected in series by a second connecting body 416, and the axes of the two parts are kept consistent after the two parts are connected. The spray paint required for use may be supplied from a paint storage tank 42 and the carrier gas selected may be supplied from an external air compressor.

The air passage tube 44 passes through the first and second housings 414 and 421, and is connected to the air passage tube 44 of the air motor 419. The feed tube 43 passes through the first housing 414 and the second housing 421 and interfaces with the feed tube 43 of the second nozzle 418.

The driving wheel 413 is provided with a hydraulic telescopic rod 4133 for connecting the first wheel 4131 and the first housing 414, and the bottom of the driving wheel 413 is provided with a micro hydraulic tank 4134 for providing pressure required by the hydraulic telescopic rod 4133. Wherein, 4 groups of driving wheels 413 are arranged in a crisscross manner and have the same structure; the power cell 4135 inside the first housing 414 is centrally disposed and reserves a space through which the air passage tube 44 and the feed tube 43 pass.

The positioning wheel 417 is used to ensure that the axes of the driving mechanism 411 and the spraying mechanism 412 are consistent, and has no power function, so as to reduce unnecessary control units and connection lines. The positioning wheel 417 is composed of a second wheel 4171, a sliding chamber 4173, a sliding rod 4172 built into the sliding chamber 4173, a compression spring 4174, and a partition 4175. When an external force presses the second wheel 4171, the compression spring 4174 is contracted and deformed, and the elastic force is transmitted through the slide bar 4172 to fix the second wheel 4171 to the inner wall of the boiler tube. Wherein, 4 sets of positioning wheels 417 are arranged in a criss-cross manner and have the same structure. The pneumatic motor 419 inside the second housing 421 is centrally disposed, and a space through which the feeding pipe 43 can pass is reserved between the second housing 421 and the pneumatic motor 419; the pneumatic motor 419 is provided with an air passage pipe 44 interface at the tail part for connecting the air passage pipe 44, a second coupling 422 is arranged at the top part for connecting the second nozzle 418, the second nozzle 418 is provided with a strip-shaped opening, and the coating is sprayed to the inner wall of the boiler pipe from the strip-shaped opening through the centrifugal force generated by high-speed rotation.

In order to guarantee the quality of the sprayed coating, the spraying device 41 works in a reverse spraying mode during use. Before spraying, the extending lengths of the hydraulic telescopic rod 4133 and the sliding rod 4172 are adjusted, the spraying device 41 is arranged in the inner cavity of a boiler pipe to be sprayed, and an external air compression device and the coating storage tank 42 are connected; starting a power battery 4135 to provide power for direct current motors 4132 of the four driving wheels 413, so that the spraying device 41 moves to the foremost end of the boiler pipe to be sprayed; the front camera 420, the rear camera 415 and the thickness measuring sensor 423 are turned on to monitor the coating process of the paint.

FIG. 7 is a schematic view of the screen-type bulk thermosetting sintering apparatus of FIG. 1; FIG. 8 is a front view of the crawler of FIG. 7; FIG. 9 is a top view of the crawler of FIG. 7; FIG. 10 is a side view of the crawler of FIG. 7; FIG. 11 is a schematic view of the screen-type integral heating, curing and sintering apparatus of FIG. 7 in an operating state; as shown in fig. 7, 8, 9, 10 and 11, the screen-type bulk thermal curing sintering apparatus includes an air-cooled induction heating coil 24, a coil moving track 22, a crawler 23, an intelligent control cabinet 25 and an induction coil power supply 21; one end of the coil moving rail 22 is adapted to be disposed on the boiler ceiling 15, and the other end extends vertically downward beyond the bottom of the boiler tubes; the crawler 23 is arranged at the inner side of the coil moving track 22, and the air-cooled induction heating coil 24 is connected with the crawler 23; the induction coil power supply 21 is electrically connected with the air-cooled induction heating coil 24; the intelligent control cabinet 25 is electrically connected with the crawler 23, and the intelligent control cabinet 25 controls the crawler 23 to drive the air-cooled induction heating coil 24 to move along the coil moving track 22 so as to sinter the boiler tubes in the air-cooled induction heating coil 24.

The screen type integral heating, curing and sintering device further comprises a first stopper 231 and a second stopper 232; the first stopper 231 and the second stopper 232 are provided at intervals on the coil moving rail 22 to limit the operation start and end positions of the crawler 23 on the coil moving rail 22.

Specifically, the air-cooled induction heating coil 24 has both ends fixed to the crawler 23, the crawler 23 is installed inside the coil moving track 22, the intelligent control cabinet 25 is electrically connected to the crawler 23, and the induction coil power supply 21 is connected to the air-cooled induction heating coil 24 through the crawler 23; the coil moving rails 22 are fixed at their upper ends to the boiler ceiling 15, and the lower sections are vertically suspended below the bottoms of the boiler tubes, and the coil moving rails 22 are usually used in pairs. A first stopper 231 and a second stopper 232 are spaced apart from each other on the coil moving rail 22, the first stopper 231 may be disposed at a position 0.3m below the boiler ceiling 15, the second stopper 232 may be disposed at a position 0.5m below the bottom of the boiler tube for automatically positioning the start and end positions of the operation of the crawler 23, and the crawler 23 is located between the first stopper 231 and the second stopper 232 while keeping both ends horizontal.

The coil moving track 22 is provided with a track clamping groove 221, and a track sliding ball 222 capable of rolling for 360 degrees is embedded in the track clamping groove 221. Crawler 23 includes coil fixing bolt 233, drive motor 236, boss 237, second wire inlet hole 235, and first wire inlet hole 234. The crawler 23 is connected with the coil moving track 22 through a boss 237 and a track clamping groove 221, wherein the track sliding balls 222 are used for reducing the crawling resistance of the crawler 23, the driving motor 236 provides crawling power, and the crawler 23 crawls up and down by setting the driving motor 236 to rotate forwards and backwards. Before the boiler tube is subjected to heat treatment, the system is built and installed, wherein large auxiliary equipment such as an induction coil power supply 21 and an intelligent control cabinet 25 are uniformly distributed on the whole heating system and fixed at the position of a boiler ceiling 15, other parts are arranged in a vertical and downward mode, and the span size of an air-cooling induction heating coil 24 is flexibly changed according to the size of a boiler tube panel 14 and is not limited by the sizes of workpieces such as the boiler tube panel 14.

As a preferred mode of the present embodiment, the crawler 23 is located at the position of the first stopper 231 by adjusting the crawler 23 through the intelligent control cabinet 25, the power, the operation rate, the operation time, and the like required by the boiler tubes are set according to the information such as the heat treatment temperature required by the boiler tubes, the sizes of the boiler tubes, and the like, the power, the operation rate, the operation time, and the like required by the air-cooled induction heating coil 24 are set, the operation button of the intelligent control cabinet 25 is started, under the adjustment of the PLC in the intelligent control cabinet 25, the crawler 23 starts to crawl from top to bottom under the driving of the driving motor 236, the induction coil power supply 21 is automatically turned on when passing through the first stopper 231, the air-cooled induction heating coil 24 starts to automatically perform chemical heat treatment on the tube panel 14 formed by the boiler tubes, and simultaneously crawls downwards along with the crawler 23 continuously, after the heat treatment of the entire tube panel 14 is completed and reaches the second stopper 232, the intelligent control cabinet 25 sends a signal, the induction coil power supply 21 is automatically turned off, the induction heating is stopped, the crawler 23 starts to crawl from bottom to top under the reverse rotation of the driving motor 236 until the driving motor is recovered to the initial position, and the intelligent control cabinet 25 stops working, and completes the heat treatment process of the tube panel 14.

In another embodiment, a method for improving the resistance of small-caliber boiler tubes of a coal-fired boiler to steam oxidation is provided, comprising the steps of: cutting the boiler tube panel 14 from a boiler ceiling 15, then vertically hoisting and fixing, and cutting a section from the bottom of a lower elbow of the boiler tube panel 14; cleaning the inner tube walls of each tube in the boiler tube panels 14; sintering the inner pipe wall of each pipe body in the boiler tube panel 14 with an oxidation-resistant coating; weld repairs are made to each tube in the sintered boiler tube panels 14.

According to the method for improving the steam oxidation resistance of the small-caliber boiler tube of the coal-fired boiler, the boiler tube panel 14 is cut from the boiler ceiling 15, then the boiler tube panel is vertically hoisted and fixed, and a section is cut from the bottom of the lower elbow of the boiler tube panel 14; cleaning the inner pipe wall of each pipe body in the boiler pipe panel 14; then, sintering the anti-oxidation coating on the inner pipe wall of each pipe body in the boiler pipe panel 14; and finally, welding and repairing each pipe body in the sintered boiler tube panel 14. All the construction processes can be completed in the hearth during the shutdown maintenance period, the production efficiency is high, the maintenance period can be obviously reduced, the steam oxidation resistant layer can be formed on the inner wall of the small-caliber boiler pipe, and the steam oxidation resistant capability of the small-caliber boiler pipe of the in-service coal-fired boiler can be greatly improved.

Wherein, specifically include when clearing up the interior pipe wall of every body in the boiler tube panel 14: removing oxide scales growing on the inner wall of each boiler tube in the service tube panel 14 by using a sand blasting device 31; the sand material sprayed out by the sand blasting device 31 comprises one or more of brown corundum, white corundum and quartz sand, and the granularity of the sand material is less than 500 meshes.

Wherein, carrying out the sintering of anti-oxidant coating to the interior pipe wall of every body in boiler tube panel 14 specifically includes: coating the boiler pipe cleaned by sand blasting with paint by using a spraying device 41; sintering the boiler tube coated with the coating by adopting a screen type integral heating curing sintering device to form an antioxidant coating on the inner tube wall of the boiler tube, wherein the sintering temperature can be 800-900 ℃, and the heat preservation time is controlled to be 10-15min. And a sand blasting device 31 is adopted to clean residues of the sintered boiler pipe.

Wherein, the preparation of the coating adopts the aluminum powder and the nickel powder with the mass ratio of 1:1 as the penetrating agent, the phosphate aqueous solution as the solvent, crO3 as the acid inhibitor and MgO as the curing agent, and the penetrating agent is prepared according to the proportion of 100 g: 100ml of an aqueous phosphate solution: 10g of acid inhibitor: 2g of curing agent.

Preferably, the coating is sprayed to a thickness of 0.2mm to 0.3mm.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications can be made without departing from the scope of the invention.

Claims (10)

1. The utility model provides a device for improving coal fired boiler small-bore boiler pipe is anti steam oxidation which characterized in that includes at least:

the sand blasting device is suitable for removing oxide skin growing on the inner wall of each boiler tube in the service tube panel; the sand blasting device comprises a hollow motor, a first nozzle and a sand pipe; the hollow motor is connected with the first nozzle and is suitable for driving the first nozzle to rotate so as to enable sand in a cavity of the first nozzle to be sprayed out through the strip-shaped opening on the surface of the first nozzle; the one end of sand material pipe is passed hollow motor and is stretched into in the cavity of first nozzle, the other end is suitable for and communicates with outside sand material source:

the spraying device is suitable for coating the boiler pipe subjected to sand blasting cleaning with paint;

the screen type integral heating, curing and sintering device is suitable for sintering the boiler tube coated with the coating so as to form an antioxidant coating on the inner tube wall of the boiler tube.

2. The apparatus for improving the resistance of small-caliber boiler tubes of a coal-fired boiler to steam oxidation according to claim 1,

the sand blasting device further comprises a traction rope, one end of the traction rope is connected with one end, far away from the first nozzle, of the hollow motor, the other end of the traction rope is suitable for being connected with an external traction device, and therefore the external traction device can drive the sand blasting device to move in the boiler pipe through the traction rope.

3. The apparatus for improving the resistance of small-caliber boiler tubes of a coal-fired boiler to steam oxidation according to claim 1,

the outer wall of the hollow motor and/or the first nozzle is sleeved with an annular sealing ring, and the outer diameter of the annular sealing ring is consistent with the inner diameter of a boiler pipe.

4. The apparatus for improving the steam oxidation resistance of small-caliber boiler tubes of a coal-fired boiler according to claim 1,

the spraying device comprises a driving mechanism and a spraying mechanism which are connected, the driving mechanism is suitable for driving the spraying mechanism to move in the boiler pipe, and the spraying mechanism is suitable for spraying the coating on the inner wall of the boiler pipe.

5. The apparatus for improving the resistance of small-caliber boiler tubes of a coal-fired boiler to steam oxidation according to claim 4,

the driving mechanism comprises a first shell, a driving wheel and a power battery;

a plurality of driving wheels are arranged on the outer wall of the first shell at intervals along the circumferential direction of the first shell, and each driving wheel can move in a telescopic manner along the radial direction of the first shell;

the power battery is arranged in the first shell, is electrically connected with each driving wheel and is suitable for driving the driving wheels to rotate.

6. The apparatus for improving the resistance of small-caliber boiler tubes of a coal-fired boiler to steam oxidation according to claim 5,

the spraying mechanism comprises a second shell, a second nozzle, a pneumatic motor, an air path pipe and a feeding pipe;

the second shell is connected with the first shell, and the second nozzle is arranged at one end of the second shell, which is far away from the first shell;

the pneumatic motor is arranged in the second shell, an air outlet of the pneumatic motor is communicated with an air inlet of the second nozzle, and an air inlet of the pneumatic motor is communicated with an external air source through an air path pipe;

one end of the feeding pipe is communicated with the feeding hole of the second nozzle, and the other end of the feeding pipe is communicated with an external coating source.

7. The apparatus for improving the steam oxidation resistance of small-caliber boiler tubes of a coal-fired boiler according to claim 6,

and a plurality of positioning wheels are arranged on the outer wall of the second shell at intervals along the circumferential direction of the second shell, and each positioning wheel can stretch and move along the radial direction of the second shell.

8. The apparatus for improving the resistance of small-caliber boiler tubes of a coal-fired boiler to steam oxidation according to claim 6,

the spraying device also comprises a front camera, a rear camera and a thickness measuring sensor which are suitable for monitoring the spraying process;

the front camera is arranged at one end of the second shell, which is far away from the first shell;

the rear camera is arranged at one end of the first shell, which is far away from the second shell;

the thickness measuring sensor is arranged at one end, far away from the first shell, of the second shell.

9. The apparatus for improving the resistance of small-caliber boiler tubes of a coal-fired boiler to steam oxidation according to claim 1,

the screen type integral heating, curing and sintering device comprises an air-cooled induction heating coil, a coil moving track, a crawler, an intelligent control cabinet and an induction coil power supply;

one end of the coil moving track is suitable for being arranged on a boiler ceiling, and the other end of the coil moving track vertically extends downwards and exceeds the bottom of the boiler pipe;

the creeper is arranged on the inner side of the coil moving track, and the air-cooled induction heating coil is connected with the creeper;

the induction coil power supply is electrically connected with the air-cooled induction heating coil;

the intelligent control cabinet is electrically connected with the crawler, and the intelligent control cabinet controls the crawler to drive the air-cooling induction heating coil to move along the coil moving track so as to sinter boiler tubes in the air-cooling induction heating coil.

10. The apparatus for improving the steam oxidation resistance of small-caliber boiler tubes of a coal-fired boiler according to claim 9,

the screen type integral heating, curing and sintering device further comprises a first stopper and a second stopper;

the first limiting stopper and the second limiting stopper are arranged on the coil moving track at intervals so as to limit the operation starting point and the operation end point of the crawler on the coil moving track.

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