RU2343999C2 - System and method of pipe coating - Google Patents

Abstract

FIELD: technological processes, coating.

SUBSTANCE: invention concerns pipe coating, particularly system and method of coating and/or renovation of worn or pitted pipes in order to extend lifetime and improve performance. Internal pipe device includes conical coating element featuring several distanced edges. End flange can remove excessive coating material from pipe. This system and method allows application of thin coating film onto internal pipe surface with regular thickness covering all pipe areas. Coating material can be selected to minimise heat conductivity change or to ensure such work fluid medium change inside the pipe as to prevent negative interaction of the medium with pipe material.

EFFECT: regular coating of internal pipe surface.

15 cl, 18 dwg

Description

Related Applications

This application is filed with a claim of priority according to the following pending applications: US Provisional Application No. 60 / 637,879, filed December 20, 2004, US Provisional Application No. 60 / 637,789, filed December 20, 2004, and US Provisional Application No. 60 / 580,930, filed June 18, 2004, with respect to the subject matter of the invention common to these applications. The contents of the above applications are fully incorporated into this description by reference.

FIELD OF THE INVENTION

The present invention relates to pipe coatings, and more particularly, to a system and method for coating and / or updating worn or ulcerated pipes to extend the service life of pipes and improve their performance.

State of the art

Metal pipes have many different functions in a wide range of industrial applications. One example is the use of metal pipes in heat exchange systems. Liquids or gases moving inside and outside the heat exchanger tubes provide heating or cooling of choice. One of the heat exchange applications relates to a condenser. A condenser is typically used to cool the steam moving outside the heat exchanger tubes, inside which cooling water is passed. Corrosion, wear, erosion, ulceration and contamination of the condenser pipes have a significant impact on the efficiency of the heat exchanger. In addition to this, the costs of maintenance, water, chemicals, part replacement, and downtime during repairs are important factors related to the functioning of the condenser or heat exchanger tubes.

The purpose of the pipes in the heat exchange system is to serve as a barrier between the cooling medium (most often in the form of water) and heated gas or liquid, as well as to facilitate heat exchange. Over time, the inner surfaces of the pipes may ulcerate or erode, and eventually may begin to leak and cease to serve as an effective barrier.

In order to prevent or slow the occurrence of ulceration or erosion inside the pipes, epoxy coatings and other reducing compounds were used. In particular, coatings were used for pipes made of copper-based alloys to protect their inner surface at the inlet end, where water turbulence combined with the action of suspended solids can cause harm from accelerated erosion. Success in preventing collapse in this area was with coatings extending into the pipe to a depth of 3 to 24 inches.

In addition to this, recently covering the entire length of the pipe has been practiced. Since coatings often significantly reduce the contamination and corrosion of pipe internal surfaces, long-term service of coated pipes can ultimately be better than uncoated pipes. One potential side effect associated with the use of coatings is the degree to which heat transfer varies due to the different characteristics of the coatings. Various factors influence how the coating affects heat transfer, including but not limited to factors such as thermal conductivity of the coating, boundary effects between coating and pipe, boundary effects between multiple coatings, laminar flow effects, fouling and added thickness effects. The thermal conductivity of the coating is a factor depending on the mixture of polymer and filler, in addition to how well the polymer and filler are integrated. Boundary effects are a function of the wettability of the coating and its application parameters, such as temperature, humidity, dust control and number of layers. In addition to this, the thickness of the applied coating varies depending on the number of layers. More specifically, traditionally two coating layers are applied to the inner surface of the pipes, however, one coat is preferred due to the reduction in thickness and cost of the material. Currently, the entire pipe length is typically coated using a spray process, resulting in a coating thickness of about 2-5 thousandths of an inch. This thickness may adversely affect the ability to heat transfer, lowering it by a value of 15 to 38%, without taking into account the pollution factor.

After the pipes are involved in the work in the heat exchanger, they form protective oxide layers on their surface and begin to become contaminated. If the rate of contamination is high, then the pipe's performance of its function can quickly deteriorate. Depending on the design tolerances for contamination and on the available capacity of the pipes, this deterioration can be tolerable to some extent, until the heat exchanger has to be cleaned or the pipes finally have to be replaced. Coatings can prevent the formation of oxides and also reduce the rate of contamination.

A significant problem associated with the deterioration of the heat transfer properties and the overall functioning of the heat transfer pipes is the effect of punctures or ulcerations caused by corrosion of the inner surface of the pipe. Currently, common materials used for pipe production include copper alloys, stainless steel alloys and titanium alloys, as well as carbon steel. Such pipes function by forming passive films on their working surface. When the passive film is torn, corrosion occurs. Coatings placed on the inner surface of the pipes can make the formation of a passivation layer unnecessary.

Disclosure of invention

There is a need to create an improved system and method for coating the inner surface of pipes with the goal of both providing a protective coating and repairing or updating correlated or ulcerated inner surfaces of the pipes. The present invention provides further solutions to meet this need.

In accordance with one aspect of the present invention, there is provided an in-line device for applying coating material to a pipe comprising a housing. At the first end of the housing is an element for coating. The end flange is located at the second end of the housing. The coating element is configured to distribute the coating material throughout the pipe, and the end flange is configured to remove excess coating material from the pipe to form a coating on the inner surface of the pipe.

In one embodiment of the present invention, the in-line device is designed so that it can be purged through the pipe using a propellant. The coating element and the end flange are adapted to be coated on an epoxy base. The surface of the in-tube device is modified to control the process of applying the coating material.

In accordance with another aspect of the present invention, there is provided a method for coating an inner surface of a pipe, the method comprising depositing coating material in a pipe. The in-tube device is placed in the pipe so as to push the coating material through the pipe. The in-tube device is moved along the pipe to apply the coating material to form the coating.

In a preferred embodiment of the system, method and device for coating the inner surface of the pipe, the in-pipe device is configured to be driven along the pipe using a moving mechanism. This driving mechanism may take various forms of execution, including pressure difference or mechanical means. As the in-tube device moves through the pipe, a coating is applied to the inner surface of the pipe. The applied coating can have a uniform thickness and has a minimal effect on the heat transfer characteristics of the pipe. Such a coating can fill the eroded elements in the pipe, renew worn areas of the pipe, block and heal cracks in the pipe, or can serve to apply a uniform coating to the inner surfaces of the pipe, sealing the pipe material.

In a preferred embodiment of the present invention, the in-line device used for coating may be configured such that the coating member is made of a compressible material, or, alternatively, the coating member is made of an incompressible material. The compressible coating member, in one implementation, may be of such a size that it is compressed by the action of the driving mechanism on the in-tube device. In another implementation, the incompressible coating element may be provided with a number of ridges and ribs that are part of the coating element.

Brief Description of the Drawings

The above features and advantages, as well as other features and aspects of the present invention will be better understood with the help of the following descriptions and drawings, where:

1A is a perspective view of an in-line device in accordance with one aspect of the present invention;

1B is a perspective view of an in-line device according to an alternative aspect of the present invention;

Figure 2 is an alternative general view of an in-line device in accordance with one aspect of the present invention;

Figure 3 is a General view of the head of the in-tube device according to one aspect of the present invention;

4A is a schematic illustration of an in-tube device during use in a pipe according to one aspect of the present invention;

4B is a schematic illustration of an in-tube device during use in a pipe according to an alternative aspect of the present invention;

5A, 5B, 5C, 5D, and 5E are schematic views of an in-tube device during use in accordance with one aspect of the present invention;

6 is a flowchart illustrating a method of using an in-tube device according to one aspect of the present invention; and

7A, 7B, 7C, 7D, 7E, and 7F are perspective views of alternative embodiments of an in-line device in accordance with aspects of the present invention.

The implementation of the invention

An illustrative implementation of the present invention relates to a system and method for coating and / or updating the inner surface of a pipe or tube, such as a heat exchanger pipe. The system and method include an in-tube device configured to be inserted into the pipe with a selected amount of coating material. The in-tube device is blown through the pipe with compressed air. As the in-tube device moves along the inner surface of the pipe, the in-tube device moves the coating material and applies the coating material to the inner surface of the pipe to form the coating. If there are ulcerations or other areas of wear or erosion on the inside of the pipe, the coating fills these areas to repair or update the surface of the pipe. The in-tube device can be used at the pipe application where the heat exchanger pipes are installed in their configuration. Alternatively, the pipes can be coated using the same device and process under production conditions where the pipes are manufactured for subsequent installation in a heat exchanger, or for any other application requiring a coated pipe.

1-7F, in which identical parts are denoted by the same numbers, illustrate an example implementation of a system and method for coating and / or repairing the inner surfaces of pipes according to the present invention. Although the present invention will be described with reference to examples of implementation illustrated by the drawings, it should be understood that many alternative forms can serve as an implementation of the present invention. The person skilled in the art will additionally see other ways of changing the parameters of the described implementation, such as the size, shape or type of elements or materials, and these changes will still be consistent with the spirit and scope of the present invention.

The technology of in-line mobile devices falls under the sections of fluid and gas mechanics, piping technology and chemical engineering. A general definition of the technology of in-line movable devices is the movement inside the pipe of a movable separator or device that can perform certain actions inside the pipe or tube. Such technology can be used, for example, for mechanical cleaning of a pipe using devices in the form of a scraper or ruff, or for monitoring the internal state of a pipe using a video camera. When cleaning pipes, the contents of the pipeline are pushed out tightly by a projectile called a scraper or swab, in order to almost completely remove the contents of the pipeline. The in-tube device moves along the pipe under gas or propellant pressure. The in-tube device may be spherical, elongated, or consisting of several parts. The in-tube device is larger in relation to the pipe; thus, the pipe is hermetically sealed in front and behind the in-tube device. This allows you to move the in-tube device through the pipe by the pressure of a gas or a propellant. The most commonly used gas is compressed air, and the liquid may be water or a cleaning agent or product.

It should be noted that the following description uses a heat exchanger as an example of a pipe configuration that may require the use of the present invention. However, one skilled in the art will understand that heat exchanger tubes are just one example of the use of pipe structures through which liquids or gases flow and which may require coating or repair of the inner surface of the pipe. Accordingly, the present invention is not limited to the use of a heat exchanger in pipes, but can be used with various types of pipes in various configurations having different functions. The end result of the application of the present invention is the coated and / or repaired or updated inner surface of the pipe. As such, the invention is expected to be used in any field where this type of service may be required.

Figa shows a General view of the in-line device 10 in accordance with one implementation of the present invention. The in-tube device 10 typically has a cylindrical shape, as shown, for use in a cylindrical pipe of a conventional configuration. However, one skilled in the art will understand that a cylindrical shape with a circular cross section can be modified with a particular application, so that rectangular, elongated or other sections can be an implementation of the present invention. Thus, the present invention is not limited to a generally cylindrical shape.

The in-tube device 10 includes a housing 12 having one flange end 14. The flange end 14 increases the diametric dimension of the in-tube device 10 on the flange socket to remove excess coating material, as will be described below. At the opposite end from the flange end 14, the housing 12 has a coating member 16. The coating element 16 can take many forms, as required by the coating, for example, can be made in the form of a compressible sponge, shown in Figa. In an alternative implementation, as shown in FIG. 1B, the coating member 16 ′ may be a rigid, substantially domed or conical head, the size of the corresponding pipe into which it is inserted for coating. Coating member 16 and 16 ′ may be made from a variety of materials, including but not limited to plastics, composite materials, polymers, rubber, and the like. In addition, the coating member may have various physical properties inherent in the coating member 16, 16 ′, including low compressibility for insertion into the pipe in accordance with the implementation of FIG. 1A. In an alternative implementation, as shown in FIG. 1B, the coating member may be made of a dense material that is not easily compressible. One skilled in the art will recognize that there are numerous varying physical qualities inherent in the coating element 16, 16 ′, these physical qualities being dictated by the pipe configuration and coating requirements. As described below, material for coating the inner surface of the pipe is applied to the element 16, 16 ′ as a first step in the method of coating and / or repairing the ulceration sites or eroded elements in the pipe.

Figure 2 is a General view of the in-tube device 10 of Figure 1, but shown at a different angle. In the drawings, the in-line device 10 is shown having no internal cavities. However, a person skilled in the art will understand that the main task of the casing 12 of the in-tube device 10 is to ensure the functioning of the device, which will move, and not get stuck inside the pipe, and to apply the desired coating in the proper way. Thus, the device according to the present invention does not necessarily have a continuous structure or even a closed structure, but may have internal cavities inside the in-tube device 10 to improve functioning. The housing 12 may be made of a number of different materials, including, but not limited to plastics, composite materials, metal, polymers, their combinations, etc.

Figure 3 is a General view of the element 16 ′ for coating the in-tube device 10. The element 16 ′ for coating is shown in this drawing for illustrative purposes. In FIG. 3, the coating element 16 ′ shown in detail is the same coating element 16 ′ that is shown in FIG. One skilled in the art will readily understand, as mentioned above, that a coating element can have many shapes and forms and can be made of various compatible materials.

In the illustration of the example, the coating member 16 ′ is a component separate from the housing 12 of the in-tube device 10. However, the coating member 16 ′ and the housing 12 can be one piece, as one skilled in the art will understand. The coating element 16 ′ shown in FIG. 3 has several distinctive features, one of which is a certain number or number of ribs 40 connecting the base of the head to the top of the head. The thickness of the ribs 40 becomes smaller as you approach the top of the head, and the ribs themselves disappear at the top of the head. However, such thinning is not necessary for the use of the device.

FIG. 4A is a schematic illustration of the in-tube device 10 previously shown in FIG. 1B after being inserted into the pipe 18 or pipe. For clarity, the in-line device 10 and the attached coating element 16 ′ of FIG. 1B were used to indicate the orientation of the in-line device 10 when it is located in the pipe 18 or the pipe. The present implementation, however, is not intended to be limiting in any way, and one skilled in the art will readily understand that a wide variety of in-tube devices and related coating elements can be similarly located in the interior of pipe 18 or pipe . For example, as shown in FIG. 4B, the in-line device 10 and the associated coating member 16 of FIG. 1A can easily be inserted into the coating pipe 18.

The pipe 18 may be made of a number of different materials, such as metal, plastic, composite material, ceramic, alloy, and the like. However, in the case of heat exchanger tubes, the most common material currently used is copper alloy, stainless steel, or titanium alloys. The pipe 18 has an inner surface 20 formed by the walls of the pipe 18. In the illustrated example, the pipe 18 includes eroded elements or erosion sections 22 (for example, ulceration, wear, erosion, corrosion, punctures, etc.). Erosion portions 22 show the types of defects that may occur over time in a heat exchanger pipe or other pipe. Erosion sites, as described above, can reduce the efficiency and efficiency of heat transfer of the pipe 18, and ultimately lead to leakage and cross-mixing of liquids and gases (inside and outside the heat exchanger). Accordingly, there is often a desire to correct such an erosion section 22 or eventually replace any pipes containing such erosion sections 22 in order to maintain the functioning of the pipeline.

Returning to FIG. 3, it should be noted that the rigid domed or conical embodiment of the coating element 16 helps to evenly distribute the coating applied inside the pipe 18 or tube, as will be described later. One of ordinary skill in the art will readily understand that numerous alternative designs of the coating element 16 are applicable to the present invention, and these alternative coating elements have different shapes or are made from different materials compared to the coating element shown here.

The ribs 40 of the coating element have the function of centering and stabilizing the in-tube device 10 when it moves inside the pipe 18. The ribs 40 have a size and configuration that are close to the working diameter of the in-tube device 10 or slightly smaller than the diameter of the pipe 18. For example, the working diameter, measured from the top of the ridge of one rib 40 and extending to the opposite end of the diameter of the coating element 16, is approximately 0.4 mm smaller than the diameter of the passage of the pipe 18 in accordance with one example implementation of the present invention. One skilled in the art will recognize that an exact size of 0.4 mm is not a limiting size. The size of the ribs 40 and the coating element 16 is such that the coating element 16 can slide inside the pipe 18 and not become jammed due to friction inside the pipe 18. At the same time, the working diameter of the coating element 16 must be large enough to ensure stability and prevent the hanging of the device 10 inside the pipe 18.

In an example embodiment, the ribs 40 are arranged such that no two ribs are diametrically opposed or substantially diametrically opposed. This solution is achieved by placing an odd number of spaced apart ribs 40 located at the same distance from each other around the circumference of the head. However, there may be an even number of ribs 40 having non-uniform gaps between the ribs 40, which gives the same effect of the absence of diametrically opposed or substantially diametrically opposed ribs. If two ribs were diametrically opposed, the working diameter of the coating element 16 would be substantially increased at the point of the diametrically opposite ribs 40 (the working diameter would be the sum of the diameter of the coating element and the height / thickness of both ribs). If two ribs 40 are diametrically opposed, this design increases the likelihood of a stuck device 10 inside the pipe, if, for example, one of the ribs passes a convex unevenness on the inner surface of the pipe, which presses the diametrically opposite rib against the opposite wall of the pipe, thus stopping due to friction movement of the device 10 inside the pipe. Placing the ribs 40 in a configuration having no diametrically opposed ribs reduces the likelihood of such a situation.

The coating member 16 ′ further comprises a rim 42 that projects outward from the housing 44. The rim 42 projects over the entire circumference of the coating member around the base of the head. The rim 42 is sized and configured to fit against the casing 12 of the in-tube device 10 so that when the coating member 16 is attached to the casing 12 of the in-tube device, the surface of the casing 12 is flush with the rim 42. This configuration creates a substantially smooth surface on the outside of the in-tube device 10, thereby avoiding the accumulation of coating material at the junction of the coating member 16 ′ and the housing 12. Moreover, the coating member 16 ′ It ozhet be made of a compressible material so that when exposed to a driving force at an in-tube device 10 element 16 'of the coating can be compressed and provide a passage outside cover member 16' of the coating.

The diameter of the casing 44 of the coating element 16 ′ has such a size and configuration that it fits snugly into the internal cavity of the casing 12 of the in-tube device 10. For the convenience of aligning the coating element 16 with the casing 12, a flat portion 46 is provided on one side of the coating element 16 . The flat portion 46 allows any air that is trapped inside the housing 12 of the in-tube device 10 to escape while the coating member 16 is attached to the housing 12. This facilitates the attachment of the coating member 16 ′ to the housing 12 of the in-tube device 10.

As already mentioned, the casing 44 of the coating element 16 ′ fits snugly into the casing 12 of the in-tube device. The connection may be due to the frictional force that holds these parts together. Alternatively, adhesives or other mechanical bonding agents may be used to attach the coating member 16 ′ to the housing 12 of the in-tube device 10, as one skilled in the art will recognize.

5A, 5B and 5C show an in-line device 10 during use in combination with a pipe 18, and also show the final result of a repair made using the present invention. On figa at one end of the pipe 18 shows the in-line device 10 using a solid, with ribs, element for coating. As mentioned above, the use of a continuous, with ribs, element 16, 16 ′ for coating is shown only as an illustrative example of the present invention. One of ordinary skill in the art will readily recognize that numerous alternative coatings are directly applicable to the present invention. These suitable alternative designs and material choices for the coating element 16, 16 ′ may be based on various factors, including but not limited to the pipe bore diameter, the coating used, the proposed coating thickness, and the pipe length 18 that the in-line device 10 must pass.

Prior to introducing the in-tube device 10 into the pipe 18, a selected amount of coating material 24 is placed in the pipe 18. Alternatively, the coating material 24 may be placed on the head of the coating element 16 of the in-pipe device 10. The amount of coating material 24 to be placed depends on a number of factors, including the length of the pipe 18 to be coated, coating thickness, specific configuration of the in-line device 10 used to apply the coating material 24, environmental factors (such as moisture durability and temperature), type of coating material 24 and related coating properties (such as viscosity), etc. Examples of coating materials 24 include, but are not limited to, such as epoxies, phenols, vinyl esters, polyesters, urethanes, other polymers and coating materials. The particular type of coating material used will depend mainly on the purpose of the coating and on the environment in which it is applied and will function, as one skilled in the art will understand. For example, the coating material may contain numerous additives to improve pipe performance or to reduce problems. A non-limiting list of suitable additives includes materials such as wax, silicone, and other types of dry lubricants, such as molybdenum disulfide.

In addition, to combat the development of biological organisms on the inner surface of the pipe, various algaecides, biocides and fungicides can be added to the coating, which kill or inhibit the growth of such organisms. The development on the inner surface of pipes of biological organisms, such as algae, fungi, bacterial and other microorganisms, can lead to contamination of the pipe surfaces, as well as to the occurrence of obstructions inside the pipes. Such contaminants and obstructions can reduce the heat transfer in the pipe, as well as restrict or stop the flow of liquid or gas. Moreover, the presence of bioorganisms can enhance various types of pipe wall corrosion, which can lead to wear and ultimate pipe failure. The addition of algicides, biocides and fungicides to the coating material thus prevents or minimizes such problems. Suitable substances for preventing the development of bioorganisms include, but are not limited to, such as orthophenylphenol (OPPS); isothiazole derivatives (such as 2-n-octyl-4-isothiazolin-3-1 (OIT)); guanides and biguanides; carbamates and dithiocarbamates; pyrithione of copper, sodium or zinc; benzimidazoles; n-haloalkylthio compounds; 1- (3-chloroallyl) -3,5,7-triaz-1-azioniaadamantane chloride; tetrachloro-isophthalonitriles; cis- [1- (3-chloroallyl) -3,5,7-triaz-1-azoniaadamantane] chloride and 2,2-dibromo-3-nitropropionamide (DBNPA); and quaternary ammonium compounds.

In addition, the coating materials of the present invention may have different viscosities. Unlike traditional coating methods in which the coating material is sufficiently diluted using a solvent, the coating material of the present invention can be used in an undiluted, highly viscous state. The use of a diluent solvent helps overflow the existing coating material through the pipe and helps control the processing time. After coating the pipe with diluted material, wait for the solvent to evaporate from the material so that the coating freezes. Since heat exchanger pipes have a very low diameter to pipe length ratio to maximize surface area for heat transfer, such limited space often makes it difficult for solvent to leave the pipe. Any ulceration in the pipe wall that can be filled with a diluted coating further increases this difficulty, so the likelihood that some amount of solvent may remain in these cavities is greatly increased.

In contrast, when a coating material of the present invention is pushed through a pipe, a coating with a higher initial viscosity can be used in an undiluted state. For example, coatings with a viscosity of 100,000 centipoises or more can easily be used. In this light, the risks of incomplete solvent removal are eliminated.

As shown in FIG. 5B, the in-tube device 10 is pushed through the pipe 18 in the direction of arrow A, leaving behind a coating 26 formed from a thin layer of coating material 24. The direction in which the in-tube device 10 passes through the pipe 18 is indifferent to the implementation of the invention as long as the coating element 16, 16 ′ is in front of the in-tube device 10. The operation of the in-tube device 10 is described as follows. Coating material 24 is collected around the coating member 16, 16 ′. This effect is caused by the forces of resistance and friction, which press the coating material 24 into the in-tube device 10 as it moves through the pipe 18. During the movement of the in-tube device 10 through the pipe 18, the gaps between the ribs 40 of the coating element 16, in one implementation, allow some the amount of coating material 24 to flow or pass through the coating element 16 and collect along the housing 12 of the in-tube device 10, between the housing 12 and the inner surface 20 of the pipe 18 in front of the flange end 14. As the in-tube device 10 continues to move in the direction of arrow A, the flange end 14 also moves and removes excess coating material 24 to form a coating 26. In another embodiment, while the in-tube device 10 moves through the pipe, the coating member 16 is compressed , thereby allowing passage of the coating material through the region defined by the coating member.

An even distribution of the coating material 24 is achieved by the combined action of the coating member 16, 16 ′ controlling the initial amount of coating material 24, which is introduced into the region between the housing 12, and the flange end 14 pressed against the inner surface 20. As mentioned above, one skilled in the art It will be readily understood by the art that the coating element 16, 16 ′ can take many forms and can be made from various materials. Regardless of the choice of material or shape of the coating element 16, the coating element must be able to pass a predetermined amount of coating material through it to an area defined by the housing 12 and the flange end 14.

In the case of an eroded element or erosion section 22, the in-tube device 10 can be used to apply a coating patch 28. In short, the amount of coating material 24 is controlled by the coating member 16, 16 ′ so that a sufficient amount is available to fill the erosion section 22 in the form of ulceration or unevenness in the pipe 18 as the in-tube device 10 passes the ulceration or bumps. When the in-tube device 10 passes over the erosion section 22, the coating material 24 fills any depressions. Then, when the flange end 14 extends over the erosion portion 22, any excess coating material 24 is removed, leaving enough material to form a coating patch 28 filling the erosion portion 22. In areas on each side of the erosion section 22, a coating 26 is applied to the inner surface 20.

According to one example, a propulsion mechanism, such as compressed gas or liquid, can be used to push the in-tube device 10 along the length of the pipe 18. In an example embodiment, this propulsion mechanism acts on the flanged end 14 of the in-tube device 10. As the in-tube device 10 is applied, moves along the pipe 18 to its far end. Depending on the particular configuration of the pipe, the in-line device 10 may continue to run through the connecting element into the next pipe or alternatively leave the pipe 18. One skilled in the art will understand that the motor mechanism used to move the in-line device 10 along the length of the pipe 18 can take many forms . These propulsion mechanisms include, but are not limited to, such as compressed gases, liquids, and the like, a pressure difference such as a vacuum, and a piston-like device that can be used to manually push the in-tube device 10 through the pipe. The Applicant has determined that a compressed propellant is currently the most effective; however, other propulsion mechanisms or forces may be used to move the in-tube device 10 through the pipe.

In addition to this, the in-tube device 10 can be dragged through the pipe 18 by means of a pull rod, such as a wire, cable, tape, rod, etc., made of any number of various materials, including synthetic, non-synthetic, metals, plastic, composite materials , woven, non-woven, etc. Accordingly, the present invention is not limited to the specific material or structure of the device used to pull the in-pipe device 10 through the pipe 18. Alternatively, a negative pressure differential can be used to push the in-pipe device 10 through the pipe 18.

The use of the in-line device 10 allows the user to further control the size of the final coating 26. More specifically, the in-line device 10 can be modified by changing its parts, such as the coating element 16, 16 ′ or the end flange 14, to achieve the specific result of the desired coating having a predetermined and substantially constant thickness and coating distribution. For example, the coating member 16, 16 ′ may vary in material, size and shape in order to allow the flow or passage of a selected amount of coating material for coating. In addition, the diameter or width of the housing 12 may vary to control the amount of material 24 passed to the tail flange 14. In addition, the size and shape of the end flange 14 and the housing 12 may vary to control the distribution and amount of material applied to the inner surface 20.

The configuration of the in-line device 10, as well as the removing action of the end flange 14, makes it possible to significantly improve the control of the hiding power and thickness of the coating 26. In accordance with one embodiment of the present invention, the in-line device 10 allows coating to be deposited with a thickness of the order of 0.25 thousandths of an inch or less. As a result of this, it becomes possible to apply a coating having a minimal effect on the heat transfer properties of the pipe, in which the coating covers the inner surface in areas that are in good condition, and at the same time corrects ulceration and other erosion sections 22. Thus, the overall effect of using the in-line device 10 according to the present invention in a pipe of good condition is that it provides a coating of much smaller thickness than in the known solutions, with a minimal effect on heat transfer, but with improved wear resistance and the ability to withstand corrosion and other pollution elements or wear. The overall effect of using the in-line device 10 according to the present invention in a pipe having erosion portions 22 impairing the functioning of the pipe is that the pipe is repaired and renewed, and restored to a significantly improved state, which removes the need to stop the system and replace the pipes. In addition, the present invention can be used for coating in a pipe 18 that is not affected by erosion or contamination, the resulting coating having a minimum thickness. Such a uniform coating using the present invention is useful in industrial applications where the material of which the existing pipe is made is incompatible with the liquid or gas intended for use in the pipe. For example, in the refrigeration part, a conventional copper heat exchanger in operational condition can be coated with the present invention so that a thin coating is uniformly applied to all areas inside the tubes of the heat exchanger. This uniform coating covers all exposed copper surfaces on the inside of the pipe. After applying such a coating, a refrigerant incompatible with copper may be used, since now the inside of the heat exchanger tubes does not have open copper regions. One skilled in the art will readily understand that this is only an illustrative example of the use of the present invention to ensure compatibility of the inner surface of the pipes with the intended working fluid or gas that will be contained within the pipe. This example clearly does not exhaust all potential pipe applications with a new coating.

5D and 5E show an alternative implementation of an in-line device when it is used with a compressible coating member 16. This illustrative example is an alternative implementation of the present invention and is not intended to narrow the applicability of the present invention. 5D, an in-line device 10 is shown at one end of the pipe 18, while the selected amount of coating material 24 is already placed inside the pipe 18. As mentioned above, the amount of coating material 24 used depends on a number of factors related to the particular application.

As shown in FIG. 5E, the in-tube device 10 is pushed through the pipe 18 in the direction of arrow A, leaving a uniform coating 26. In the present embodiment, the coating material 24 is collected around the coating member 16. This effect is caused by the forces of resistance and friction that press the coating material 24 into the in-tube device 10 as it moves through the pipe 18. During the movement of the in-tube device 10 through the pipe 18, the coating element 16 moves or compresses sufficiently to allow a certain amount of coating material 24 flows through the coating element 16 and collect along the housing 12 of the in-tube device 10, between the housing 12 and the inner surface 20 of the pipe 18, in front of the flanges end 14. As the in-tube device 10 continues to move in the direction of arrow A, the flange end 14 also moves and removes excess coating material 24 to form the coating 26. Using the compressible coating member 16 as shown in this embodiment, as well as a rigid, ribbed coating element shown in FIG. 5A is not an exhaustive list of potential implementations of a coating element. One skilled in the art will readily understand that there are numerous alternative implementations of the coating element 16 that are applicable to the present invention. These alternative implementations can take many forms or forms and can be made from various materials suitable for coating.

6 is a flowchart illustrating a method of using the in-line device 10 according to an embodiment of the present invention. The coating material 24 and the in-tube device 10 are introduced into the pipe 18 (step 100). A driving force is applied, blowing the in-tube device 10 through the pipe 18 (step 102). During the movement of the in-tube device 10 through the pipe 18, the coating material 24 is placed on the inner surface 20 of the pipe 18 to form the coating 26 (step 104). Optionally, the process can be repeated to apply additional layers of coating material 24 (step 106). It should be noted that if additional layers of coating material 24 are applied, these layers may be formed from another type of coating material 24 or the same as the original coating material 24. In addition, if the process is repeated, various in-tube devices 10 having different properties or characteristics can be used to form coating layers with different properties. Moreover, depending on the coating material 24, it may take time to set and solidify the coating.

7A-F show several examples of alternative implementations of the in-line device 10 in the form of in-line devices 10A-10F. In-tube devices 10A and 10D have an additional feature in the form of longitudinal surface elements 30. In-tube devices 10B and 10E have an additional feature in the form of transverse surface elements 32. The addition of longitudinal surface elements 30 and transverse surface elements 32 are an example of the variability of various alternative implementations in which the surface The casing 12 is modified to influence the distribution of the coating material 24 using an in-line device. One skilled in the art will understand that various orientations and combinations of surface elements, coating element designs (i.e., shape, material selection and compressibility) in addition to those not specifically described or illustrated, are possible in accordance with this invention. Accordingly, the present invention is not limited to the illustrated implementation examples.

In FIGS. 7C and 7F, the end flange 34 of the in-tube device 10C contains a number of recesses 36. When the flange 34 passes over the coating material 24, the recesses 36 on the end flange 34 form a corrugation on the coating 26 formed on the inner surface 20 of the pipe 18. A concrete pattern formed coating 26 may vary, as one skilled in the art will understand, depending on the shape of the flange. Such a flange 34 may be useful if several passes of the in-tube device are required. The first application of the coating material 24 may have as its main purpose the application of it in the form of a pre-installed corrugated pattern, while subsequent passages of the in-tube device can smooth or otherwise modify the resulting coating. Alternatively, a corrugation or other pattern formed in the coating may be the final configuration of the coating, if such corrugations or patterns are desired.

The first applications of the in-line coating device 10 in the pipe 18 resulted in a coating thickness of about 0.25 to 1 thousandths of an inch, the coating of the inner surface 20 being uniform. The heat transfer analysis of the coated pipe showed a minimal effect on the heat transfer properties. Pipes having one or more ulcerations were quickly repaired by using an in-line device 10 and an epoxy coating to apply a resistant patch to the ulceration, thereby extending the life of the pipe.

Accordingly, the present invention is useful in that when using an in-line coating or patch device, it provides substantially better control of the hiding power and coating thickness on the inner surface of the pipe. Where the previous methods resulted in a minimum coating thickness of 2 to 5 thousandths of an inch, the present invention provides a much thinner single coating layer of the order of 0.25 to 1 thousandths of an inch, thin enough so that the resulting coating does not significantly degrade performance heat transfer pipe. In addition, the in-tube device can be passed through the pipe several times, which provides several layers of coating, if you need a more durable or thicker coating. A compressed propulsion device in the form of gas or liquid quickly moves the in-tube device along the pipe, effectively coating the inner surface.

Numerous modifications and alternative embodiments of the present invention are apparent to those skilled in the art from the above description. Accordingly, this description should be understood only as illustrative, it serves the purpose of training specialists in this field of technology the best method of implementing the present invention. The details of the construction can vary significantly without deviating from the essence of the present invention, and the right to all modifications falling within the scope of the attached claims is reserved. It is intended that this invention be limited only to the extent determined by the appended claims and applicable law.

Claims (15)

1. An in-line device for applying coating material to a pipe, comprising a body not serving as a container for said coating material; a coating element located at the first end of the housing, said first end being the end of the in-tube device that is first inserted into the pipe to be coated, and the coating element has a conical shape and is provided with a number of spaced apart ribs providing passage of the coating from the outside coating element; an end flange located on the second end of the housing, and the coating element is configured to distribute coating material previously placed in the pipe inside the pipe, and the end flange is configured to remove excess coating material from the pipe to form a coating in the form of a single thin layer on the inner surface of the pipe, while the specified coating is thin enough to prevent deterioration to a large extent of the heat transfer characteristics of the pipe. 2. The device according to claim 1, characterized in that it is arranged to be driven along the pipe by means of a driving mechanism. 3. The device according to claim 2, characterized in that the driving mechanism drives the in-tube device along the pipe using either a pressure differential or mechanical means. 4. The device according to claim 3, characterized in that the mechanical means are made in the form of a traction cable. 5. The device according to claim 3, characterized in that the driving mechanism is a compressed fluid. 6. The device according to claim 1, characterized in that the size and orientation of the surface of the in-tube device are selected from the conditions for ensuring the application of the coating material in an adjustable manner. 7. The device according to claim 1, characterized in that the coating material is selected from the group of the following materials: epoxy resin, phenol, vinyl ether, polyester, urethane and polymer. 8. The device according to claim 1, characterized in that the coating contains an additive for use in coating the pipe. 9. The device according to claim 8, characterized in that the additive is a biocide, fungicide or algicide. 10. A system for coating the inner surface of a pipe, comprising an in-tube device with a housing not serving as a container for said coating material; a coating element located at a first end of the housing, said first end being the end of the in-tube device that is first inserted into the pipe to be coated, and the coating element is made of compressible material to allow the coating to pass outside the coating element; an end flange located at the second end of the housing, the coating element being configured to distribute coating material previously placed in the pipe over the inner surface of the pipe, and the end flange is configured to remove excess coating material from the pipe to form a single thin coating layer on the inner surface of the pipe, while the specified coating is thin enough to prevent deterioration to a large extent of the heat transfer characteristics of the pipe. 11. The system of claim 10, characterized in that the coating applied to the pipe has a uniform thickness. 12. The system of claim 10, characterized in that the coating fills the eroded elements in the pipe. 13. The system of claim 10, characterized in that the coating blocks cracks in the pipe. 14. The system of claim 10, wherein said compressible material is a sponge. 15. The system of claim 10, characterized in that the thickness of the specified coating in the form of a single thin layer is of the order of 0.25 thousandths of an inch or less of the specified value to have a minimal effect on the heat transfer characteristics of the pipe.

Images