RU2179076C2 - Method of and device for applying corrosion-resisting coating on internal surface of pipeline - Google Patents

Abstract

FIELD: agriculture and reclamation facilities, particularly, methods of applying fluid material on the internal surface of hollow body (pipe). SUBSTANCE: coating is applied on the internal surface of pipe-line at a speed of 0.3-0.5 m/s. The device is provided with means of the individual supplying of coating material and rust transformer under operation pressure. The means are connected with the injection nozzle. The nozzle is conical and receives threaded rod provided with turns of screw. EFFECT: enhanced efficiency due to reduced consumption of paint coating. 2 cl, 4 dwg

Description

 The method of applying anti-corrosion insulation on the inner surface of the pipeline and a device for its implementation.

 The invention relates to agricultural and land reclamation equipment, in particular to methods for applying fluid material to the inner surface of a hollow body (pipe) and to a technique for applying protective coatings as anti-corrosion insulation to the inner surface of a pipeline.

A known method of applying a fluid material to the inner surface of a hollow summer, having a through at least approximately cylindrical hollow space, in which a loaded material and a loaded stream of carrier gas is fed through the hollow space from one end of the hollow body to the other, in which, in order to to ensure uniform application of the material, several unloaded material gas flows are directed to the interior before and during the supply of the material-loaded carrier gas stream into the hollow space rennyuyu the end surface of the hollow space that spin in the same direction as the loaded material flow of carrier gas (SU, patent N 1620042. A3. M.kl. ⁵ B 05 C 7/02, B 05 B 7/10. The method of applying fluid material to the inner surface of a hollow body and a device for its implementation // Beat Eckert, Guido Huber, Norbert Richle (CH). Declared 07/02/1987, published 01/07/1991).

 The disadvantages of this method include uncontrolled coating thickness and the need for expensive additional installations for supplying compressed carrier gas.

There is also a known method of coating the inner surfaces of pipes, in which the coating material — a cement-sand mixture — is supplied to a spray nozzle at a pressure of 0.04 MPa, the coating material is directed onto the surface of the cone and broken into a thin layer descending from the cone, then coating in the form of a thin layer, they are oriented on the inner surface of the pipe with curved blades, the thickness of the applied coating is normalized by removing the excess mass of the cement-sand mixture (SU, copyright certificate N 1416203. A1. M. class. ⁴ B 05 C 7/02, B 05 B 13/06 . Devices for coating the inner surfaces of pipes // V.F. Zakrzhevsky. Declared 05/15/1986, published 08/15/1980).

 The disadvantages of the described method include the fact that the coating is applied to an unprepared surface for applying an anti-corrosion coating to the inner surface of the pipes of the main water supply system, and this is unacceptable. The rust between the described coating and the surface of the material intensively corrodes the main material - the steel wall of the pipe.

A device is known for applying fluid material to the inner surface of a hollow body having a through at least approximately cylindrical hollow space containing a passage for a carrier-loaded gas stream in the form of a diffuser, a supply line for a material-loaded carrier gas stream in the form of a diffuser, a supply line of a material-loaded carrier gas stream and means for swirling a material-loaded carrier gas stream, in which, in order to ensure uniform application of materials Alas, the means for swirling the carrier gas flow loaded with the material are made in the form of guide vanes placed in the diffuser cavity with an inclination to its axis, and the throughput body is equipped with nozzles installed at the outlet of the diffuser on the guide vanes, in communication with the supply source of the unloaded gas material and inclined to the axis of the diffuser cavity in the direction of inclination of the guide vanes in order to impart a swirl of the carrier gas to the loaded gas stream and to a non-loaded carrier gas stream with the same direction HAND rotation; the diffuser with its inlet part is installed at a distance from the output end of the supply line of the carrier gas stream loaded with material; the guide vanes of the swirling means are curved in cross section in the form of a trough with a radius of curvature increasing in the direction of flow with a concave side directed to the rotating stream, while the guide vanes are curved in the longitudinal direction to the outlet of the diffuser and increasing to an axis of the diffuser; guide vanes are made with sections protruding beyond the outlet edge of the passage diffuser, tapering in the direction of flow movement and forming centering means for centering the passage through the hollow space of the workpiece; it is equipped with a hollow cavity located in the cavity of the diffuser, open at both ends, conically expanding in the direction of flow passage by a displacing body in the form of a diffuser cone; the diffuser has a double-walled housing for a cooler or coolant; the nozzles are made in the form of Laval nozzles (SU, patent N 1620042. A3. Mcl ⁵ B 05 C 7/02, B 05 B 7/10. The method of applying fluid material to the inner surface of a hollow body and a device for its implementation // Beat Eckert, Guido Huber and Norbert Rehle (CH). Declared July 2, 1987, published January 7, 1991).

 The design flaws of the anti-corrosion coating device include the complexity of the structure and the supply of heated gas.

The closest analogue to the claimed object is a device for coating the inner surfaces of pipes containing a centrifugal spray assembly of the coating material, devices for smoothing the coating and centering elements, in which, in order to reduce energy consumption, the centrifugal spray assembly is made in the form of a spray nozzle and installed coaxially with the possibility of rotation of the screen in the form of a cone facing the apex towards the outlet of the nozzle and evenly behind curved blades mounted on its surface, expanding from the top to the periphery of the cone (SU, copyright certificate N 1416203. A1. M. class. ⁴ B 05 C 7/02, B 05 B 13/16. Device for coating the inner surfaces of pipes // V.F. Zakrzhevsky. Claimed 05/15/1986, published 08/15/1988).

 We accepted this device as the closest analogue in the device part.

 The disadvantages of the described device include the complexity of the design of the centrifugal spray unit of the material.

 The essence of the claimed invention is as follows.

 The problem to which the claimed invention is directed is to improve the quality of the anti-corrosion coating on the inner surface of the pipe.

 EFFECT: reduced consumption of paint and varnish coating and increased uniformity of layer distribution.

 The specified technical result in terms of the method is achieved by the fact that in the known method of applying anti-corrosion insulation, which includes applying the coating material under working pressure, forming a thin layer, applying it to the inner surface and normalizing the coating thickness, according to the invention, a protective coating is applied to the inner surface of the pipeline at a travel speed of 0.3-0.5 m / s.

 The technical result in terms of a device for applying anti-corrosion insulation to the inner surface of a pipeline containing a centrifugal spray assembly of the coating material in the form of a spray nozzle mounted coaxially to the pipe surface with the possibility of movement along its axis, and centering elements are achieved by the fact that according to the second independent claim it is equipped with devices for individual supply under the working pressure of the coating material and the rust converter, hydraulically connected with a spray nozzle made in the form of a housing, in the cavity of which a threaded rod is placed, on the continuation of which are placed the turns of the screw.

 The invention is illustrated by drawings.

 In FIG. 1 schematically shows a device for applying anti-corrosion insulation to the inner surface of a pipeline in accordance with the claimed method.

 In FIG. 2 is a view A in FIG. 1, the position of the centering elements in the pipe cavity.

 In FIG. 3 is a section BB in FIG. 2, a diametrical section of the spray nozzle.

 In FIG. 4 is a view B in FIG. 3, the position of the threaded rod holder in the cavity of the nozzle body.

 Information confirming the possibility of implementing the claimed invention are as follows.

 The method of applying anti-corrosion insulation on the inner surface of the pipeline is implemented as follows. The proposed method provides for the supply under the working pressure of the coating material. Further, a thin uniform coating layer is formed on the inner surface of the pipe. The coating layer is applied to a previously prepared surface. The coating thickness is normalized within the specified limits. Before applying a protective coating, the inner surface of the pipeline is covered with a rust converter, which reacts chemically with the corrosion products and forms the first protective layer. This ensures uniform coating of the protective layer on the pipe surface, its degreasing and the complete conversion of metal oxides. In this case, metal oxides are retained on the surface of the pipe in the form of a thin dusty layer. Next, a protective layer is applied to the prepared surface at a speed of translational movement of the device — nozzles of 0.3-0.5 m / s.

 A device for applying anti-corrosion insulation to the inner surface of the pipeline (see Fig. 1-4) contains a centrifugal spraying unit 1 of the coating material with a spray nozzle 2. The assembly 1 and the nozzle 2 are mounted coaxially to the inner surface of the pipe 3 with the possibility of movement along its axis. The node with the nozzle 2 in the cavity of the pipe 3 is placed by means of the centering elements 4 and 5.

 The device is equipped with devices 6 and 7 for individual supply under the working pressure of the coating material and the rust converter. Devices 6 and 7 are hydraulically connected to the spray nozzle 2.

 The spray nozzle 2 is made in the form of a housing 8, in the cavity of which a threaded rod 9 is placed. The threaded rod 9 is paired with a part of the body 10, on the surface of which the turns of the screw 11 are placed. The threaded rod 9 in the housing 8 is placed using a holder 12 in the form of diametrically oriented rays . The mating portion 13 of the housing 8 has a mating (mating) part of the surface of the body 10.

 Each device 6 (7) is equipped with a pump 14 for setting the working pressure in the tank capacity and a control pressure gauge 15. The tanks of the devices 6 and 7 are connected by flexible sleeves 16 and 17 through two-way valves 18 with the unit 1 of the nozzle 2.

 A device for applying anti-corrosion insulation to the inner surface of the pipeline works as follows.

The reservoirs of apparatuses 6 and 7 are filled respectively with a coating material and a rust converter. In the cavity of the pipe 3 with a diameter of D _about placed through the centering elements 4 and 5, the node 1 with the spray nozzle 2. Screwing the threaded rod 9 between the body 8 and the body 10 set the required clearance Δ (see Fig. 3). In the cavity of the reservoir of the apparatus 7 create a working pressure in the range of 0.01-0.03 MPa (1-3 kgf / cm ² ). When the valve 18 is open, the rust transducer along the sleeve 17 enters the cavity of the housing 8. In the housing 8 by turns of the screw 11, the working fluid is twisted and ejected through the annular gap, sprayed and applied to the inner cavity of the pipe 3. At the moment of contact with the pipe surface 3, the diameter of the drops of the rust converter is 0.3-0.8 mm. Their uniform coating of the surface of the pipe 3 leads to a chemical reaction. Metal oxides and grease spots are converted to a powder layer. The node 1 with the spray nozzle 2 is moved at a speed of 0.3-0.5 m / s to the second end of the pipe 3. Next, the valve 18 is closed. The spray nozzle 2 with the node 1 is returned to its original position. Change the gap Δ between the housing 8 and the body 10. Control the working pressure within 0.05-0.08 MPa in the tank capacity of the apparatus 6. Open the second valve 18. Paintwork at a working pressure of 0.05-0.08 MPa in flexible the sleeve 16 enters the housing 8 of the spray nozzle 2. Due to the turns of the screw 11, the liquid is untwisted and under working pressure is ejected in the form of fine droplets onto the surface of the pipe 3, upon impact the diameter of the drops decreases to 30-80 microns. The droplet size of the paint coating is such that it penetrates through the dusty particles of the rust converter and metal oxides, as well as onto the painted surface of the pipe 3.

 The paint coating with dusty particles of metal oxides is reinforced and adheres firmly to the surface of the pipe 3. Moving the nozzle 2 along the axis of the pipe 3 by means of centering elements 4 and 5 with a speed of 0.3-0.5 m / s provides a uniform and stable paint coating over the entire inner surface pipes 3.

 Thus, the sequential distribution of the rust converter and the paintwork in the form of finely divided particles provides a reduction in the consumption of paintwork material and improves the quality of the coating.

Claims (2)

 1. The method of applying anti-corrosion insulation on the inner surface of the pipeline, including supplying the coating material under working pressure, forming a thin layer, applying it to the inner surface and normalizing the thickness of the coating, characterized in that the protective coating is applied to the inner surface of the pipeline at a speed of 0, 3-0.5 m / s.  2. A device for applying anti-corrosion insulation to the inner surface of the pipeline, containing a centrifugal spray assembly of the coating material in the form of a spray nozzle mounted coaxially to the pipe surface with the possibility of movement along its axis, and centering elements, characterized in that it is equipped with devices for individual feeding under the working pressure of the coating material and the rust converter, hydraulically connected to the spray nozzle, made in the form of a housing, in the cavity of which threaded rod is placed, on the continuation of which turns of the screw are made.

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