CN111359814A

CN111359814A - Pipeline inner wall coating spraying system

Info

Publication number: CN111359814A
Application number: CN202010242705.XA
Authority: CN
Inventors: 杨斌
Original assignee: Beijing Boyan Zhongneng Technology Co ltd
Current assignee: Beijing Boyan Zhongneng Technology Co ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2020-07-03

Abstract

The invention discloses a pipeline inner wall coating spraying system, and relates to the technical field of pipeline spraying. The invention comprises a supporting unit, a spraying unit and a supplying unit; the supporting unit supports the spraying unit, and the supply unit is used for supplying an air source and the coating; the spraying unit comprises a first sprayer, a heater and a second sprayer, and the first sprayer, the heater and the second sprayer are sequentially arranged on the supporting rod; the first sprayer, the blower and the second sprayer are communicated with the supply unit; in the invention, a pipe to be sprayed is firstly sprayed with paint in the process of reversely moving along the arrangement direction of a first sprayer, a heater and a second sprayer; then the ejector blows the part to remove the coating which is not tightly combined; heating and strengthening the primary coating sprayed coating by a heater, and finally spraying the secondary coating by a second sprayer; the bonding strength of the coating on the inner wall of the pipe to be sprayed is improved through the process.

Description

Pipeline inner wall coating spraying system

Technical Field

The invention relates to the technical field of pipeline spraying, in particular to a pipeline inner wall coating spraying system.

Background

The pipeline is an important component of industrial production and civil facilities and is also a main facility in pipeline transportation. With the rapid development of the industry in China and the improvement of the construction speed of urban public facilities, the pipeline construction is also rapidly developed; transport pipelines are used in severe environments in some cases, and the corrosion and protection problems of the transport pipelines are always key factors related to the reliability and the service life of the pipelines.

At present, to the protection of metal pipeline inner wall, the method of taking usually is exactly at pipeline inner wall coating anticorrosion, non-stick coating, it is anticorrosive at pipeline inner wall coating anticorrosion, non-stick coating has with low costs, realize easily and advantage such as adhesion is good, however, the spraying equipment of current metal pipeline inner wall is mostly the stock spray gun, operating personnel is in the spraying process, must hand the stock spray gun and carry out the spraying to the metal pipeline inner wall, but the coating spraying is uneven very easily in the spraying process, the coating thickness that leads to firing is undulant great, and the stability of spraying material combination on pipeline inner wall is relatively poor.

The automatic spraying system also comes from the fact that the automatic spraying is a spraying method which is automatically controlled by utilizing electric appliances or mechanical principles (mechanical arms or robots), the automatic spraying is mostly controlled and monitored by adopting an industrial control computer PLC program, an automatic spraying production line is generally arranged in a closed space and comprises a conveying unit, a dust removal unit and a spraying unit, the spraying device comprises an exhaust unit and a drying unit, wherein the dust removal unit, the spraying unit and the drying unit are arranged in partitions, the exhaust unit is arranged in each partition, the conveying mechanism penetrates through the whole automatic spraying production line, workpieces or products are dedusted by the dust removal unit and then enter a spraying chamber or a spraying chamber of the spraying unit through the conveying mechanism for spraying, the workpieces or products enter a baking unit for drying after spraying, then finished products are output through the conveying mechanism, and industrial waste gas containing dust and mist coating waste gas and permeating into each partition is exhausted through the exhaust unit. Although the spraying uniformity can be improved in the spraying process of the existing automatic paint spraying unit, the sprayed paint is difficult to be effectively combined with the inner wall of the pipeline.

Through retrieval, the patent with the patent publication number of CN110314792A discloses an automatic spraying unit for workpieces with slender structures, wherein a box-shaped cover with a closed inner cavity is spanned and erected at the butt joint position of two adjacent conveying sections of a conveying line which are in butt joint end to end, the length dimension of the box-shaped cover along the front-back direction is smaller than that of the workpieces with slender structures, and a spraying input port and a spraying output port are arranged at the positions of the box-shaped cover corresponding to the conveying line; the butt joint position of two adjacent sections of conveying sections of the conveying line is also provided with a transition carrying wheel matched with the size of the bottom of the accompanying carrying frame; although the technical scheme of this patent can improve the even degree to pipeline inner wall coating spraying to a certain extent, only through the mode of once only spraying with coating spraying to pipeline inner wall on be difficult to guarantee the combination degree of coating on the inner wall, influence the extension effect of the life of spraying back pipeline to a certain extent.

Disclosure of Invention

1. Technical problem to be solved by the invention

The invention aims to provide a pipeline inner wall coating spraying system aiming at the problem of low bonding strength of a coating sprayed by a device for spraying the inner wall of a pipeline in the prior art.

2. Technical scheme

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

the invention relates to a pipeline inner wall coating spraying system which comprises a supporting unit, a spraying unit and a supply unit, wherein the supporting unit is used for supporting the spraying unit; the supporting unit comprises a supporting table, 2 supporting frames, a supporting rod and a moving table, wherein the supporting rod is horizontally arranged above the supporting table, and two ends of the supporting rod are respectively supported by the supporting frames; a movable table is arranged on the support table in a translational manner, a pipe to be sprayed is rotatably placed on the movable table, and the support rod is positioned in the pipe to be sprayed; the support rod is provided with a spraying unit; the spraying unit comprises a first sprayer, a heater and a second sprayer, and the first sprayer, the heater and the second sprayer are sequentially arranged on the supporting rod; the first sprayer, the blower and the second sprayer are communicated with the supply unit; the supply unit includes a paint tank connected to the first sprayer, the blower, and the second sprayer through pipes, and an air tank connected to the blower through pipes.

Preferably, the mobile platform is provided with a support bearing, and the support bearing is used for mounting the pipe to be sprayed so that the pipe to be sprayed can rotate axially; the moving table is also provided with a driver which is used for driving the pipe to be sprayed to axially rotate.

Preferably, the blowing device comprises a first blowing device, the first blowing device is provided with a first blowing nozzle, the blowing direction of the first blowing nozzle is obliquely arranged, and the oblique direction of the first blowing nozzle faces the direction of the first blowing device close to the first blowing device.

Preferably, the sprayer comprises a first sprayer, the first sprayer is provided with a first spray nozzle, the first spray nozzle is a Raoult spray pipe and comprises a contraction section and an expansion section, the contraction starting end of the contraction section is connected with the paint tank through a paint pipeline, and the side part of the expansion section is connected with the air tank through an air duct.

Preferably, an air suction port is arranged between the first sprayer and the first sprayer, and the air suction direction of the air suction port faces the first sprayer; the pumping port is communicated to the exhaust port through a pipeline.

Preferably, the heater is an infrared heating pipe, the length of the heater along the axial direction of the supporting rod is L, wherein L is more than or equal to 9.5m and less than or equal to 10 m; the distance between a blowing nozzle on the blowing device and the heater is d2, wherein d2 is more than or equal to 0.3m and less than or equal to 0.35 m; the distance between the second nozzle on the second sprayer and the heater is d3, wherein d3 is more than or equal to 0.3m and less than or equal to 0.35 m.

Preferably, the paint tank is connected to the first sprayer, the blower, and the second sprayer by a spray pump, and the air tank is connected to the blower by an air pump.

Preferably, the inclination angle of the first blowing nozzle is α, the distance from the first blowing nozzle to the inner wall of the pipe to be sprayed is h, and the inclination angle α satisfies tan α ═ k · h, wherein k is greater than 0 and less than or equal to 1.

Preferably, the blower further comprises a second blower, and the second blower is arranged on one side of the first blower, which is close to the first blower; the second blowing device is provided with a second blowing nozzle, and the second blowing nozzle is connected with the gas tank through a pipeline.

Preferably, the distance from the first blowing nozzle on the first sprayer to the first nozzle on the first sprayer is d1, wherein 0.2m < d1 < 0.3 m.

3. Advantageous effects

Compared with the prior art, the technical scheme provided by the invention has the following remarkable effects:

(1) the invention relates to a pipeline inner wall coating spraying system which comprises a supporting unit, a spraying unit and a supply unit, wherein the supporting unit is used for supporting the spraying unit; the supporting unit comprises a supporting table, 2 supporting frames, a supporting rod and a moving table, wherein the supporting rod is horizontally arranged above the supporting table, and two ends of the supporting rod are respectively supported by the supporting frames; a movable table is arranged on the support table in a translational manner, a pipe to be sprayed is rotatably placed on the movable table, and the support rod is positioned in the pipe to be sprayed; the support rod is provided with a spraying unit; the spraying unit comprises a first sprayer, a heater and a second sprayer, and the first sprayer, the heater and the second sprayer are sequentially arranged on the supporting rod; the first sprayer, the blower and the second sprayer are communicated with the supply unit; the supply unit comprises a coating tank and a gas tank, the coating tank is connected with the first sprayer, the sprayer and the second sprayer through pipelines, and the gas tank is connected with the sprayer through a pipeline; the spraying method comprises the following steps that a pipe to be sprayed rotates on a moving platform of a supporting unit, and the moving platform drives the pipe to be sprayed to move reversely along the arrangement direction of a first sprayer, a heater and a second sprayer, and the first sprayer firstly sprays paint at a certain position on the inner wall of the pipe to be sprayed in the process of passing through the certain position; then the blower blows the part to remove the coating which is not tightly combined with the outer surface of the primary coating sprayed coating; heating and strengthening the primary coating sprayed coating by a heater, and finally spraying the secondary coating by a second sprayer; the bonding strength of the coating on the inner wall of the pipe to be sprayed can be greatly improved through the process.

(2) According to the pipeline inner wall coating spraying system, the sprayer comprises the first sprayer, the first sprayer is provided with the first blowing nozzle, the spraying direction of the first blowing nozzle is obliquely arranged and faces the direction of the first sprayer close to the first sprayer, the first blowing nozzle can better achieve the effect of blowing off the coating which is not tightly combined with the outer surface of the primary coating spraying coating through oblique spraying, in addition, the damage to the primary coating spraying coating which is better combined in the process can be reduced, and the combination effect of the subsequent coating on the inner wall of the pipe to be sprayed is favorably improved.

Drawings

FIG. 1 is a schematic structural diagram of a system for spraying a coating on the inner wall of a pipeline according to the present invention;

FIG. 2 is a schematic diagram of the arrangement of the spraying units in the coating spraying system for the inner wall of the pipeline according to the present invention;

fig. 3 is a schematic structural view of a first blowing nozzle of the present invention.

The reference numerals in the schematic drawings illustrate:

110. a support table; 120. a support frame; 130. a support bar; 140. a mobile station; 141. a support bearing; 142. a driver; 150. spraying a pipe to be sprayed;

210. a first sprayer; 211. a first nozzle; 220. a first blower; 221. an air extraction opening; 222. a first blowing nozzle; 223. an expansion section; 224. a contraction section; 225. an air duct; 226. coating a pipeline; 230. a heater; 240. a second sprayer; 241. a second nozzle; 250. a second blower; 251. a second blowing nozzle;

310. a paint tank; 311. a stirrer; 312. a spray pump; 320. a gas tank; 321. an air pump; 330. and (7) an exhaust port.

Detailed Description

For a further understanding of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings and examples.

The structure, proportion, size and the like shown in the drawings are only used for matching with the content disclosed in the specification, so that the person skilled in the art can understand and read the description, and the description is not used for limiting the limit condition of the implementation of the invention, so the method has no technical essence, and any structural modification, proportion relation change or size adjustment still falls within the scope of the technical content disclosed by the invention without affecting the effect and the achievable purpose of the invention. Meanwhile, the terms such as "upper", "lower", "left", "right" and "middle" used in the present specification are for clarity of description only, and are not used to limit the implementable scope, and the relative relationship changes or adjustments may be considered to be within the implementable scope of the present invention without substantial technical changes; in addition, the embodiments of the present invention are not independent of each other, but may be combined.

Example 1

As shown in fig. 1, the system for spraying a coating on the inner wall of a pipeline of the present embodiment includes a supporting unit, a spraying unit, and a supplying unit; the supporting unit comprises a supporting table 110, 2 supporting frames 120, a supporting rod 130 and a mobile station 140, wherein the supporting rod 130 is horizontally arranged above the supporting table 110, and two ends of the supporting rod 130 are respectively supported by the supporting frames 120; and at least one of the two ends of the supporting rod 130 is separated from the supporting frame 120, so that the pipe 150 to be sprayed can be sleeved outside the supporting rod 130 when in use.

The support table 110 is provided with a moving table 140, the moving table 140 is rotatably disposed with a tube 150 to be sprayed, specifically, the moving table 140 is provided with support bearings 141, the support bearings 141 are used for mounting the tube 150 to be sprayed, in this embodiment, at least 2 support bearings 141 are provided, and when in use, the support bearings 141 are mounted at two ends of the tube 150 to be sprayed, so that the tube 150 to be sprayed can axially rotate; in addition, a driver 142 is disposed on the moving stage 140 for driving the tube 150 to be sprayed to rotate axially. In this embodiment, the driver 142 includes a motor and a rotating wheel driven by the motor, the surface of the rotating wheel may be made of a material with large friction and flexibility, such as a rubber material, the surface of the rotating wheel contacts with the outer surface of the pipe 150 to be sprayed, the rotating wheel rotates to drive the pipe 150 to be sprayed to rotate, and the rotating speed of the pipe 150 to be sprayed and the spraying unit rotating axially relative to each other is 10 to 100 r/min; in this embodiment, the rotation speed of the pipe 150 to be sprayed is 75 r/min.

In addition, the moving stage 140 is disposed on the supporting table 110 in a translatable manner, in this embodiment, the moving stage 140 translates on the supporting table 110 in a worm transmission manner, the supporting rod 130 is provided with a spraying unit, the supporting rod 130 is located in the pipe 150 to be sprayed, the moving stage 140 drives the pipe 150 to be sprayed thereon to move, and the spraying unit sprays the inner wall of the pipe 150 to be sprayed in the pipe 150 to be sprayed.

The spraying unit comprises a first sprayer 210, a blower, a heater 230 and a second sprayer 240, and the first sprayer 210, the blower, the heater 230 and the second sprayer 240 are sequentially arranged on the supporting rod 130; as shown in fig. 2, before the inner wall of the pipe 150 to be sprayed starts to be sprayed, the leftmost end of the pipe 150 to be sprayed in fig. 2 is positioned at the first sprayer 210 under the driving of the moving stage 140, and when spraying starts, the moving stage 140 drives the pipe 150 to be sprayed to move, and the pipe 150 to be sprayed moves to the right in fig. 2, that is, the pipe 150 to be sprayed moves in the direction opposite to the direction in which the first sprayer 210, the sprayer, the heater 230 and the second sprayer 240 are arranged on the support rod 130; the relative translation speed of the pipe 150 to be sprayed and the spraying unit along the axial direction is 80-800 mm/min, and the movement speed in this embodiment is 370 mm/min.

The first sprayer 210, the blower, and the second sprayer 240 communicate with the supply unit; the supply unit is used to supply the first sprayer 210, the blower, and the second sprayer 240 with spray paint or gas. The supply unit includes a paint tank 310 and an air tank 320, the paint tank 310 being connected to the first 210, the blower, and the second 240 sprayers through pipes, and the air tank 320 being connected to the blower through pipes. And the paint can 310 is connected to the first sprayer 210, the blower and the second sprayer 240 by a spray pump 312, the spray pump 312 functions to pump the paint in the paint can 310 into the first sprayer 210 and/or the blower and/or the second sprayer 240; the gas tank 320 is connected to the blower by a gas pump 321, and the gas pump 321 is used for pumping the gas in the gas tank 320 into the blower.

In the moving process of the pipe 150 to be sprayed, for a certain spraying position on the inner wall of the pipe 150 to be sprayed, the first sprayer 210 firstly sprays the first paint on the certain spraying position, the first nozzle 211 of the first sprayer 210 sprays the first paint on the spraying position to form a first paint spraying coating, the thickness of the first paint spraying coating is 0.4-0.6mm, and the thickness of the first paint spraying coating in the embodiment is 0.5 mm. The rotating pipe 150 to be sprayed is beneficial to the uniformity of the coating of the primary coating sprayed on the one hand, and the bonding effect of the primary coating sprayed on the inner wall of the pipe 150 to be sprayed under the centrifugal force is further improved because the pipe 150 to be sprayed rotates because the primary coating sprayed on the inner wall of the pipe 150 to be sprayed is attached to the inner wall of the pipe 150 to be sprayed. However, one of the problems that occurs after the primary coating is applied is that the surface of the primary coating applied layer still has a coating with poor bonding strength, and the presence of the coating with low bonding strength still causes the deterioration of the coating quality.

After carrying out a spraying, the spraying department moves to the corresponding position of the sprayer, the sprayer includes first sprayer 220, be provided with first blowing nozzle 222 on the first sprayer 220, the slope of the jetting direction of first blowing nozzle 222 sets up, its slope orientation is close to the direction of first sprayer 210 towards first sprayer 220, first blowing nozzle 222 can realize better not closely combining the blowdown effect of coating to a coating spraying coating surface through slope jetting.

In addition, as shown in fig. 3, the first blowing nozzle 222 is a raoult nozzle which comprises a contraction section 224 and an expansion section 223, the contraction starting end of the contraction section 224 is connected with the gas tank 320 through the air duct 225, the side part of the expansion section 223 is connected with the coating tank 310 through the coating duct 226, the gas blows the primary coating sprayed coating at a high speed under the action of the raoult nozzle, meanwhile, the coating entering from the side part of the expansion section 223 is impacted by the high-speed gas in the expansion section 223 to form droplets, the droplets are blown to the inner wall of the pipe 150 to be sprayed along with the high-speed gas flow, so that the primary coating sprayed coating is bonded with better strength, in addition, the inclination angle of the first blowing nozzle 222 is α, the distance from the first blowing nozzle 222 to the inner wall of the pipe 150 to be sprayed is h, the inclination angle α meets the condition that tan α is k · h, wherein 0 < k is less than or equal to 1, and k is 0.45 in the embodiment, and on the premise of ensuring the blowing effect, the damage to the secondary coating in the process can be reduced, and the improvement of the subsequent sprayed coating on the inner wall of the pipe 150 to be sprayed.

It should be noted that, in the process of blowing the primary paint sprayed coating, the first blowing nozzle 222 may also atomize and splash paint with weak bonding force on the original surface layer of the primary paint sprayed coating, so that the blowing apparatus in this embodiment further includes a second blowing apparatus 250, and the second blowing apparatus 250 is disposed on a side of the first blowing apparatus 220 close to the first blowing apparatus 210; the second blowing device 250 is provided with a second blowing nozzle 251, and the second blowing nozzle 251 is connected with the gas tank 320 through a pipeline; the blowing of the second blowing nozzle 251 can enable the paint which is blown by the first blowing nozzle 222 and generates atomized splashing to be bonded to the surface of the primary paint spraying coating again, and at the moment, the paint can be fully bonded with the primary paint spraying coating to play a role in strengthening the coating.

An air suction port 221 is arranged between the first sprayer 220 and the first sprayer 210, and the air suction direction of the air suction port 221 faces the first sprayer 220; the pumping port 221 is communicated to the exhaust port 330 through a pipeline; the suction opening 221 functions to discharge the residual atomized splashed coating material from the inside of the pipe 150 to be sprayed.

In addition, the distance from the first blowing nozzle 222 on the first sprayer 220 to the first nozzle 211 on the first sprayer 210 is d1, where 0.2 m. ltoreq. d 1. ltoreq.0.3 m.

After the primary paint spraying coating is subjected to blowing treatment, the primary paint spraying coating is heated and strengthened by the heater 230, the heater 230 is an infrared heating pipe, the length of the heater 230 along the axial direction of the support rod 130 is L, wherein L is more than or equal to 9.5m and less than or equal to 10m, the heating temperature of the heater 230 is 45-80 ℃, and the heating temperature in the embodiment is 65 ℃. The primary coating sprayed coating can be initially strengthened by heating the primary coating sprayed coating. And heating the reinforced primary paint spraying coating, and then spraying the secondary paint to a second sprayer 240 to form a secondary paint spraying coating, wherein the overall thickness of the coating is 0.8-1.2 mm, namely the overall thickness of the primary paint spraying coating and the secondary paint spraying coating is 0.8-1.2 mm, in the embodiment, 1.0 mm. The corrosion resistance of the coating formed by combining the primary coating sprayed coating and the secondary coating sprayed coating is good, the distance between a blowing nozzle on a blower and the heater 230 is d2, wherein d2 is more than or equal to 0.3m and less than or equal to 0.35 m; the distance from the second nozzle 241 of the second sprayer 240 to the heater 230 is d3, wherein d3 is 0.3m or more and 0.35m or less.

Taking a pipeline inner wall sample, and carrying out the following performance tests:

and (3) testing impact strength: drop hammer test (small area punch) according to ISO 6272-2e 2002;

and (3) wear resistance test: testing the abrasion resistance rating method of the organic coating according to astm d 968-93(2001) shakeout method;

and (3) weather resistance test: according to GB/T1865-1997;

the results of the performance tests are shown in table 1.

Comparative example 1

The present embodiment is basically the same as embodiment 1, except that the spraying unit in the present embodiment only includes the first sprayer 210, the heater 230 and the second sprayer 240, and is not provided with a blower, and other device parameters are the same as those of embodiment 1, the first sprayer 210 sprays and forms a primary paint spraying coating on the inner wall of the pipeline, and the thickness of the coating is 0.5 mm; heating by a heater 230 until a secondary coating spraying coating is formed at the position of a second sprayer 240 by spraying, wherein the total thickness of the secondary coating spraying coating and the primary coating spraying coating is 1.0 mm; there is no blowing process in the middle.

and (3) weather resistance test: according to GB/T1865-1997;

the results of the performance tests are shown in table 1.

Comparative example 2

The present embodiment is basically the same as embodiment 1, except that the spraying unit in the present embodiment only includes the first sprayer 210, the blower, and the second sprayer 240, and the heater 230 is not provided, and other device parameters are the same as embodiment 1, the first sprayer 210 sprays and forms a primary paint spraying coating on the inner wall of the pipeline, and the thickness of the coating is 0.5 mm; then, the mixture is blown by a blowing device, the blowing parameters are the same as those of the embodiment 1, and a secondary coating spraying coating is formed at the position of the second spraying device 240 by spraying, wherein the total thickness of the secondary coating spraying coating and the primary coating spraying coating is 1.0 mm; there is no heating process in between. Taking a pipeline inner wall sample, and carrying out the following performance tests:

and (3) weather resistance test: according to GB/T1865-1997;

the results of the performance tests are shown in table 1.

Comparative example 3

The present embodiment is basically the same as embodiment 1, except that the spraying unit in the present embodiment only includes the first sprayer 210, the blower and the heater 230, and the second sprayer 240 is not provided, and other device parameters are the same as embodiment 1, the first sprayer 210 sprays and forms a primary paint spraying coating on the inner wall of the pipeline, and the thickness of the coating is 1.0 mm; then blowing through a blower, and heating and curing after blowing; the blowing preheating parameters are the same as those in the embodiment 1; there was no secondary spraying. Taking a pipeline inner wall sample, and carrying out the following performance tests:

and (3) weather resistance test: according to GB/T1865-1997;

the results of the performance tests are shown in table 1.

Table 1 comparative plot of properties for each example

As can be seen from Table 1, the impact strength, abrasion resistance and weather resistance of the coating formed in example 1 are significantly improved as compared with those of the coatings in comparative examples 1 to 3.

The invention has been described in detail hereinabove with reference to specific exemplary embodiments thereof. It will, however, be understood that various modifications and changes may be made without departing from the scope of the invention as defined in the appended claims. The detailed description and drawings are to be regarded as illustrative rather than restrictive, and any such modifications and variations are intended to be included within the scope of the present invention as described herein. Furthermore, the background is intended to be illustrative of the state of the art as developed and the meaning of the present technology and is not intended to limit the scope of the invention or the application and field of application of the invention.

More specifically, although exemplary embodiments of the invention have been described herein, the invention is not limited to these embodiments, but includes any and all embodiments modified, omitted, combined, e.g., between various embodiments, adapted and/or substituted, as would be recognized by those skilled in the art from the foregoing detailed description. The limitations in the claims are to be interpreted broadly based the language employed in the claims and not limited to examples described in the foregoing detailed description or during the prosecution of the application, which examples are to be construed as non-exclusive. Any steps recited in any method or process claims may be executed in any order and are not limited to the order presented in the claims. The scope of the invention should, therefore, be determined only by the appended claims and their legal equivalents, rather than by the descriptions and examples given above.

Claims

1. A pipeline inner wall coating spraying system is characterized by comprising a supporting unit, a spraying unit and a supply unit;

the supporting unit comprises a supporting table (110), 2 supporting frames (120), a supporting rod (130) and a mobile station (140), wherein the supporting rod (130) is horizontally arranged above the supporting table (110), and two ends of the supporting rod (130) are respectively supported by the supporting frames (120); a moving table (140) is arranged on the support table (110) in a translational manner, a pipe (150) to be sprayed is rotatably placed on the moving table (140), and the support rod (130) is positioned in the pipe (150) to be sprayed; a spraying unit is arranged on the supporting rod (130);

the spraying unit comprises a first sprayer (210), a sprayer, a heater (230) and a second sprayer (240), and the first sprayer (210), the sprayer, the heater (230) and the second sprayer (240) are sequentially arranged on the supporting rod (130); the first sprayer (210), the blower and the second sprayer (240) are communicated with the supply unit;

the supply unit includes a paint tank (310) and a gas tank (320), the paint tank (310) being connected to the first sprayer (210), the blower, and the second sprayer (240) through pipes, and the gas tank (320) being connected to the blower through pipes.

2. The system for spraying the paint on the inner wall of the pipeline as claimed in claim 1, wherein the moving table (140) is provided with a supporting bearing (141), and the supporting bearing (141) is used for installing the pipe (150) to be sprayed so that the pipe (150) to be sprayed can rotate axially; the moving platform (140) is also provided with a driver (142) which is used for driving the pipe (150) to be sprayed to rotate axially.

3. The system of claim 1, wherein the blower comprises a first blower (220), the first blower (220) is provided with a first nozzle (222), and the blowing direction of the first nozzle (222) is inclined towards the direction of the first blower (220) close to the first blower (210).

4. The system for spraying the paint on the inner wall of the pipeline as claimed in claim 1, wherein the sprayer comprises a first sprayer (220), a first spray nozzle (222) is arranged on the first sprayer (220), the first spray nozzle (222) is a Raoult spray pipe and comprises a contraction section (224) and an expansion section (223), the contraction starting end of the contraction section (224) is connected with the air tank (320) through a vent pipeline (225), and the side part of the expansion section (223) is connected with the paint tank (310) through a paint pipeline (226).

5. The system for spraying the paint on the inner wall of the pipeline according to claim 1, wherein an air suction opening (221) is arranged between the first sprayer (220) and the first sprayer (210), and the air suction direction of the air suction opening (221) faces to the first sprayer (220); the pumping port (221) is communicated to the exhaust port (330) through a pipeline.

6. The system for spraying the coating on the inner wall of the pipeline as claimed in claim 1, wherein the heater (230) is an infrared heating pipe, the length of the heater (230) along the axial direction of the supporting rod (130) is L, and L is more than or equal to 9.5m and less than or equal to 10 m; the distance between the blowing nozzle on the blowing device and the heater (230) is d2, wherein d2 is more than or equal to 0.3m and less than or equal to 0.35 m; the distance from the second nozzle (241) to the heater (230) on the second sprayer (240) is d3, wherein d3 is more than or equal to 0.3m and less than or equal to 0.35 m.

7. A system for coating an inner wall of a pipeline according to claim 1, wherein the paint tank (310) is connected to the first sprayer (210), the blower and the second sprayer (240) by a coating pump (312), and the air tank (320) is connected to the blower by an air pump (321).

8. The system of claim 3, wherein the first nozzle (222) has an inclination angle of α, the first nozzle (222) is at a distance h from the inner wall of the pipe (150) to be sprayed, and the inclination angle α satisfies tan α -k-h, where 0 < k ≦ 1.

9. The system of any one of claims 3 or 4, wherein the blower further comprises a second blower (250), the second blower (250) being disposed on a side of the first blower (220) adjacent to the first blower (210); the second blowing device (250) is provided with a second blowing nozzle (251), and the second blowing nozzle (251) is connected with the air tank (320) through a pipeline.

10. The system of any one of claims 3 or 4, wherein the first nozzle (222) of the first sprayer (220) is spaced from the first nozzle (211) of the first sprayer (210) by a distance d1, wherein d1 is 0.2m 0.3 m.