WO2020204742A1 - Method for forming coatings on long cylindrical articles and devices for the implementation thereof - Google Patents

Abstract

In order to allow even distribution of a layer of coating over the surface of an article and to centre said article during movement, a long cylindrical article with an uncured coating is moved, under the effect of a fluid medium, through a coating forming and curing device and an article cooling and centering device arranged in series. In the coating forming and curing device, which has an opening for the movement of an article, an uncured coating is acted on by a fluid medium which flows over the surface of the article, forming a coating and providing for curing of said coating as a result of cooling, heating or the chemical reaction of the coating material with the fluid medium material. The article cooling and centering device comprises a housing having an opening for the movement of an article and further having a pair of parallel channels into which a fluid medium is fed, said channels being arranged symmetrically in relation to the opening for the movement of an article and communicating with said opening via diametrically opposite regions, wherein the axes of said pair of channels lie in a plane perpendicular to the axis of the opening for the movement of an article, and the fluid medium, passing through said pair of channels in a direction perpendicular to the movement of the article, acts on the article such as to hold it between the channels and to complete the cooling of the article.

Description

METHOD FOR FORMING COATING ON LONG-DIMENSIONAL

CYLINDRICAL PRODUCTS AND DEVICES FOR ITS IMPLEMENTATION

The invention relates to the field of surface treatment of a product and can be used for uniform distribution of a coating of a given thickness, for example, a coating from a molten metal on the surface of long cylindrical products with simultaneous cooling of the product. The scope of the invention: in galvanization - coating wires, pipes; in the fiber-optic industry - covering the optical fiber with the required coating layer; cable industry - wire coating with epoxy resin, paint, etc .; pipe industry - anti-corrosion coating for pipes, etc.

Various methods and devices are known that make it possible to remove excess melt that forms a coating on an article, to adjust the thickness of the coating and to center (stabilize) the position of the article while moving it.

In particular, there is a known installation for hot dip coating of a metal strip (RU2656435, С23С 2/00, publ. 06/05/2018), which makes it possible to control the quality and thickness of the metal strip coating. The installation contains means for moving the metal strip along the trajectory, a tank containing a bath with a melt, and a stripping system containing at least two nozzles located on each side of the trajectory after the tank, each nozzle having at least a gas outlet, and the stripping system has a compartment with a lower insulating part for isolating the atmosphere around the metal strip in front of the nozzles and an upper insulating part for isolating the atmosphere around the metal strip after the nozzles, while the stripping system has a first movement means for vertically moving the lower insulating part relative to the tank, while the nozzles are configured moving vertically relative to the tank, and the stripping system comprises a second movement means for vertically moving the upper insulating part relative to the tank and the lower insulating part.

Known device for adjusting the thickness of the applied zinc coating on the strip (RU 18838U, C23C 2/20, publ. 20.07.2001), containing facing each other slot nozzles communicated with the supply system of compressed gas, while the permissible deviation from the flatness of the working surfaces of each of the nozzles should be no more than 12% of the size of their slot gap, while the roughness of the said working surfaces of the nozzles is R _a 0.2-0.8 μm.

Known device for removing liquid coating material by means of a gas flow from a heated wire (DE 19652686A1, C23C 2/20, publ. 06/25/1998), while the gas flow is directed against the direction of movement of the wire. The device includes a chamber that is rigidly attached to the body and defines a cylindrical cavity in which the stripping block is enclosed. This block includes an annular nozzle with radial holes and constrictor inserts. As the wire moves, the nozzle can move freely with low friction within the cylindrical cavity, centering relative to the wire within the required tolerance. The gas stream used to strip the coating material and center the annular nozzle enters the cylindrical cavity through the body.

An electromagnetic device is known for stabilizing the position of a strip of ferromagnetic material during coating (RU 2557044, C23C 2/00, publ. 20.07.2015), which stabilizes the strip and minimizes its deformation by applying forces that are distributed continuously in the direction transverse to the strip regardless of its width.

There is a known method of processing a cylindrical product with a fluid medium (RU 2186638, V08B 3/04, publ. 08/10/2002), in which the product is moved in a vortex flow of a medium enclosed in a vortex chamber, and the processing of the product is carried out in the mode of precession of the vortex flow axis and the product axis relative to the axis of the vortex chamber. The high-speed rotation of the medium is due to the fact that the outflow of the vortex flow occurs forcibly, through the crescent-shaped gap between the product and the conductive channel of the vortex chamber. Since the size of the vortex flow section decreases, the rotation speed of the medium increases in inverse proportion to the size of this section. Accordingly, the intensity of the impact of the environment on the surface of the product also increases.

The disadvantage of this method is associated with the fact that under certain conditions there is an almost complete removal of the melt with the exception of the coating material that has entered into a chemical reaction with the product material. Moreover, for With a decrease in the total gas consumption, the thickness of the coating increases, nevertheless remaining insignificant. If we continue to reduce the gas consumption, then in this case it is impossible to obtain a uniform distribution of the coating over the surface of the product, since pulsations of the vortex flow may occur, causing different local thickness of the coating.

The closest analogue is a method of forming a coating from a melt on the surface of a cylindrical product (RU 2268951, С23С 2/18, publ. 27.01.2006), in which the coated product is moved in a vortex fluid flow, enclosed in a vortex chamber, in the mode of axis precession vortex flow and the axis of the product relative to the axis of the vortex chamber, while the vortex flow is directed along the axis of the chamber simultaneously towards the product and in the direction of movement of the product, while changing the ratio of the flow components and / or their values until a coating of a given thickness is obtained. The gas flow flowing out towards the moved product ensures the removal of excess melt from the surface of the product and its primary distribution over the surface of the product, while the gas flow outflowing from the vortex chamber in the direction of movement of the product ensures secondary distribution and crystallization of the melt without the formation of defects, in particular capillary waves. This method is implemented by means of a device that is a vortex chamber with tangential gas inlet. The walls of the chamber are made in the form of truncated cones, at the tops of which the wires are fixed, respectively, at the inlet and outlet of the product from the vortex chamber. Inside the vortex chamber there is a flow divider, the configuration of which is similar to the internal shape of the vortex chamber. The flow divider is fixed on the guides with the possibility of its predetermined and fixed movement by the value L along the guides inside the chamber. In this case, depending on the change in the parameter L, the value of the flow ratio changes. The device allows directing a vortex flow simultaneously towards the product and in the direction of movement of the product, changing the ratio of these flows and their magnitude, and thus, from the melt to form a smooth, uniformly distributed over the surface of the product, a coating of a given thickness.

To implement this method requires a rather complex device and high energy consumption to create a vortex flow. The technical problem solved by the invention is to simplify the method and the devices that implement it, which make it possible to form a uniformly distributed coating of a given thickness on the surface of the article and provide the possibility of a wide control of the range of coating thicknesses with effective cooling of the article.

The specified problem is solved due to the fact that a coating is formed on a long cylindrical product (for example, a wire, an optical fiber, a tube) by passing the specified product through a container with a liquid material forming a coating, after which the product with an uncured coating is directed to at least sequential one device intended for the formation and curing of the coating (hereinafter - the device for the formation and curing of the coating), and at least one device intended for cooling and centering the product, while in the body of the device for the formation and curing of the coating along its longitudinal axis a hole is made for moving a coated article having a diameter greater than that of the coated article. A channel communicating with it for supplying and removing a fluid medium, passing across the axis of the product in the space between the wall of the hole for moving the product and the product itself, is connected to said hole. flowing around the entire surface of the product. The longitudinal plane of the channel for supplying fluid is perpendicular to the axis of the hole for moving the product or is inclined to it. Further, from the device for forming and curing the coating, the article is directed to the second device, the function of which is to cool and center the article (hereinafter referred to as the centering device), while the device for centering also has an opening for moving the article having a diameter that exceeds the diameter of the coated article, at least four pairs of pairwise diametrically located channels for supplying fluid are connected to the hole for moving the product of the device for centering, communicating with the hole for moving the product, while the axes of the paired channels are located at an angle to each other. It is preferable that the axes of the different pairs of channels, arranged in series or not in series, are set at an angular interval of 45 ° to each other.

In addition, it is possible to change the parameters of the fluid flow (in particular, the speed, density, etc.) flowing in the channels of the coating formation and curing device to obtain a coating of a given thickness and quality, 5 and / or change the parameters of the fluid flow (velocity, temperature, etc.) in the channels of the centering device in order to eliminate fluctuations in the article and ensure effective final cooling.

The action of a fluid flow on the product in the coating formation and curing device leads to a uniform distribution of the coating over the surface of the product and ensures its smoothness, and due to the action of the fluid, the coating hardens due to thermal action, namely, due to cooling (or heating) by the fluid. or by chemically reacting the coating material with the fluid material (eg, a hardener). The uniformity of the distribution of the coating over the surface of the product is achieved by the action of the pressure of the fluid flowing around the product in the direction perpendicular to the movement of the product, and due to the laminar flow around the product (no flow eddies). In the centering device, the presence of paired channels, the number of which is determined by necessity and which are located diametrically opposite to the hole for moving the product, excludes transverse vibrations of the product due to the dynamic pressure of the fluid, acting symmetrically on the opposite surfaces of the product, and at the same time the product is finally cooled, after which it you can, for example, be wound on bobbins, spools, etc. or transfer to the step of applying a second coating layer.

The fluid can be a liquid, for example water or a hardening agent, or a gas, or a mixture of gases, for example, air, or a mixture of other gases, preferably inert to the coating material.

In the device for the formation and curing of the coating, the channel for the inlet and outlet of the fluid should be located so that it forms a common channel with the hole for moving the coated article, while the axes of the channel for the inlet and outlet of the fluid lie in a plane perpendicular to the longitudinal axis of the hole for moving the article, and fluid flows in the gap (space) between the article and the wall of the hole to move the article.

The technical result achieved as a result of the implementation of the inventions (method and devices for implementing the method) is to ensure the uniformity of the distribution of the coating layer over 6 of the surface of the product (ensuring concentricity), while the cured layer of the coating can be obtained both by thermal action, namely, by cooling or heating by a fluid, and by chemical interaction, for example, when the product is coated with a material that hardens under the influence of substances hardeners used in this case as a fluid. In addition, the invention makes it possible to ensure the centering of the product being washed by the fluid, i. E. stabilization of its spatial position due to the forces of action of the fluid, which are distributed in the direction transverse to the movement of the product, which allows eliminating the natural vibrations of the product and ensuring the translational movement of the product in the desired position while maintaining the coating layer intact. In this case, it is possible to regulate the flow of a liquid or gas flowing around the product by changing the flow rate, by changing the temperature of the flow and / or the composition of the fluid medium (liquid, gas mixture), and it is also possible to obtain the specified coating parameters by changing the location of the channel for supplying the flow medium or channel shape. The device for forming and curing the coating, and the device for cooling and centering the product, can be used as part of existing coating lines both together (installed in series) and separately. The devices carrying out the actions of the method are compact, while the essential advantages of the claimed group of inventions is that for the implementation of the method and the use of the proposed devices, no fundamental change in the design of the existing coating lines is required. The device for forming and curing the coating and the device for centering can be installed in the required places of existing or newly created lines for coating, including lines for applying multi-layer coating. The use of inventions to create a multi-stage process for creating coatings, for example, multilayer, is possible, since the claimed method allows several coating processes to be performed sequentially in one production line, for example, it allows a second coating layer to be applied over the formed first layer, and this leads to a simplification of the process, reduction of energy consumption and obtaining a higher quality multilayer coating. In addition, the claimed method and the devices implementing it can be used both in technological lines with horizontal movement of the product, and in production lines with vertical movement of the product. 7

Reducing energy consumption in the first device is achieved by the fact that a laminar fluid flow is used to form the coating and cure it, which requires less energy, in contrast to the closest analogue, where a vortex flow is created for the same purposes.

The centering device consists of at least four elements, each of which provides control of the impact in only one direction (horizontally - left-right, or vertical - top-bottom, or oblique - at 45 °). For more effective impact, the number of elements in the centering device can be more than four.

The invention is illustrated by drawings, which show:

FIG. 1 - a device intended for the formation and curing of the coating, general view.

FIG. 2 is a cross-section of a device for forming and curing a coating.

FIG. 3 shows a device for forming and curing a coating, showing a fluid channel and an opening for passing a coated article.

FIG. 4 and FIG. 5 - options for flowing around a coated article with a fluid flow in a device intended for forming and curing the coating.

FIG. 6 - device intended for cooling and centering the product, general view.

FIG. 7 shows a device for cooling and centering an article, showing fluid channels and an opening for passing a coated article.

FIG. 8 - element of the device designed for cooling and centering the product.

FIG. 9 is a sectional view of an element of the second device for cooling and centering the product.

The implementation of the claimed method is shown by the example of applying a single coating layer.

The surface of the product on which the coating is supposed to be applied is pre-cleaned, then the product is coated by immersion in a liquid coating material (zinc, aluminum and its alloys, lead, polymer, 8 component epoxy resin, paint, etc.). Directly behind the container with the liquid coating material (or after the device for removing excess coating), a device 1 for forming and curing a coating, and a device 2 for centering are sequentially located. Device 1 and device 2 are positioned coaxially, i.e. so as to provide a straight-line unimpeded passage of a long cylindrical product coated thereon sequentially through these devices providing control of the thickness of the coating and simultaneous cooling of the coated product while ensuring the centering of the product.

The device 1 for the formation and curing of the coating (see Fig. 1 - 3) contains a body formed of two parts 3 and 4, connected to each other and made so that they form a channel 6 for supplying and removing a fluid medium, while the body has a longitudinally located hole 11 for accommodating and moving therein the coated article 5, the diameter of the hole 11 being greater than the diameter of the coated article 5 passing through it. This is necessary so that a fluid medium can enter the space between the wall of the hole 11 and the surface of the coating of the article 5. Structurally, the body parts 3 and 4 are made so that the channel 6 for supplying and removing the fluid and the opening 11 communicate with each other and form a single channel for the fluid supplied under pressure, while the fluid flows around the product in the direction transverse to the axis of the product. The longitudinal plane of the channel 6 for supplying and removing the fluid at the point of its connection with the hole 11, as a rule, is perpendicular to the longitudinal axis of the hole 11 for moving the article 5, but it can also be located obliquely to it.

FIG. 4 and 5 schematically show two options for how a coated article is flowed around. FIG. 4 illustrates a variant corresponding to the structure of the coating formation and curing device 1 shown in FIG. 1-3. FIG. 5 shows a variant of the flow around the coating of the article 5, if the channel b has a different shape.

FIG. 6-9 shows a centering device 2. A separate element of the centering device 2 is shown in FIG. 8. Each element of the device 2 comprises a housing, in which there is a longitudinally disposed opening 11 for moving the coated article 5, made similar to the opening 11 in the device 1 for forming and curing the coating, i. E. hole diameter 11 9 is slightly larger than the diameter of the coated article 5 passing through it. The body also has a pair of parallel channels 12, the axes of which lie in a plane perpendicular to the axis of the holes 11, into which the fluid is supplied under pressure. A longitudinal section of the centering device 2 is shown in FIG. 9. Parallel channels 12 are located so that they cut off the segment of the cylindrical hole 11 and communicate with it along the plane formed by the chords of the segments.

Each centering device consists of at least four elements shown in FIG. 8-9, each of which provides control of the impact in only one direction (horizontally - left-right, or vertical - top-bottom, or oblique - at 45 °). For more effective impact, the number of blocks in the centering device can be more than four.

In the example shown in FIG. 6 and 7 show device 2 with eight elements, in two of which (item 7) channels 12 are located vertically and stabilize the product in the horizontal plane, in the next two elements (item 8) the channels are located horizontally and stabilize the product in the vertical plane, in the next two elements (pos. 9) the channels are located at an angle (+ 45 °) and stabilize the product in an inclined (+ 45 °) plane, in the next two elements (pos. 10) the channels are located at an angle (-45 °) (in plane perpendicular to the channels 12 of the elements 9) and stabilize the product in an inclined angle (-45 °) perpendicular to the plane of the channels 12 of the elements 9. Each element of the device 2 has diametrically opposite contact areas of the product with a fluid medium, while a pair of channels 12 by means of a fluid, passing through them, acts on the product, forcing it to be in the area of minimum pressure, that is, in the central zone between the channels of the fluid, thereby eliminating the beating of the product when e moving, which additionally improves the quality of the applied coating. Elements 7-10 are placed one after the other so as to act on the product with a fluid around the circumference with a 45 ° pitch, centering and simultaneously cooling it, after which the product can be wound on bobbins, coils, etc. or transfer to the step of applying a second coating layer.

Claims

Claim 1. A method of forming a coating on a long cylindrical product, which consists in passing a long cylindrical product through a container with a liquid material forming a coating, then the product with an uncured coating is moved, providing its interaction with a fluid medium, characterized in that the interaction with a fluid medium is carried out in a successive device for forming and curing a coating and a device for cooling and centering the product, while in a device for forming and curing a coating having a hole for moving the product, the uncured coating is exposed to a fluid flowing around the surface of the product to form a coating and ensure its solidification due to cooling, or heating, or chemical interaction of the coating material with the fluid material, then the product is fed into a device for cooling and centering the product, in the body of which an opening is made for moving the product and , in addition, a pair of parallel channels is made, into which the fluid is supplied, and said parallel channels are symmetrically located relative to the hole for moving the product and communicate with it, providing contact of the product with the fluid flowing through the channels, while the axes of the said pair of channels lie in the plane , perpendicular to the axis of the hole for moving the product. 2. The method according to claim 1, characterized in that the opening for moving the article in the body of the coating forming and curing device is made with a diameter that exceeds the diameter of the coated article, while a channel for supplying and withdrawing a fluid communicating with it is connected to said opening, flowing around the surface of the coated product. 3. The method according to claim 1 or 2, characterized in that in the device for cooling and centering the product, a hole for moving the product is made, having a diameter exceeding the diameter of the coated product, at least four pairs of diametrically located channels for supplying fluid, communicating with the hole for moving the product, while the axes of each pair of channels are located at an angle to each other, and the fluid passing through said 11, a pair of channels in the direction perpendicular to the movement of the product acts on the product to hold it in between the channels and for its final cooling. 4. The method according to claim. 3, characterized in that the axes of several pairs of channels of the device for cooling and centering the product are located at an angle of 45 ° to each other. 5. A method according to claim 1, characterized in that, to obtain a coating of a given thickness, the parameters of the fluid flow in the channels of the coating formation and curing device are changed and / or to eliminate oscillations of the article, the parameters of the fluid flow in the channels of the cooling and centering device are changed. 6. The method according to claim 1, characterized in that a liquid, or a gas, or a mixture of gases is used as a fluid. 7. A method according to claim 6, characterized in that water or a hardening agent is used as the fluid. 8. The method according to claim 2, characterized in that in the device for forming and curing the coating, the channel for supplying and removing the fluid medium is made so that it forms a common channel with the opening for moving the coated article, while the axes of the channel for supplying and removing the fluid medium are located in a plane perpendicular to the longitudinal axis of the hole for moving the article, and the fluid passes in the gap between the article and the wall of the hole for moving the article. 9. The method according to claim 3, characterized in that the centering device consists of at least four elements, each of which provides centering control in one direction, namely in one plane. 10. A device for forming and curing a coating on a long cylindrical product, comprising a housing with an opening for moving the coated product, characterized in that said opening is in communication with a channel for supplying and removing a fluid medium, which is made to form a common channel with an opening for moving the product with a coating, and the axes of the fluid inlet-outlet channel are located in a plane perpendicular to the longitudinal axis of the hole for moving the product. 12 11. A device for cooling and centering the product, comprising a housing with an opening for moving the product, characterized in that the housing has at least four pairs of parallel channels for supplying fluid, symmetrically located relative to the opening for moving the product and communicating with it in diametrically opposite areas, while the axes kakhshchay of the mentioned pairs of channels are located in a plane perpendicular to the axis of the hole for moving the product, and the axes of successively located channels are oriented at an angle to each other.