RU2485360C1 - Formation method of molecular coating on surfaces of products from metals and alloys - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: method consists in formation on surfaces of a structured film by creating emulsion of surface active substances (SAS), dosing the emulsion to fluid medium; at that, as SAS, biologically and thermally non-decomposed compounds are used, which are chemically inert in relation to fluid media, for example film-forming amines; the above medium is heated to the temperature that is higher than fusion temperature of used SAS; products are cleaned from corrosion products and deposits; the product is placed into fluid medium; electromagnetic field is created by introducing to fluid medium of an electrode; the electrode is connected to one pole of a current source, and the product from metal or alloy is connected to the other one; temperature and electromagnetic field is exposed till the end of formation process of molecular coating.

EFFECT: improving reliability, corrosion resistance and service life of products from metals and alloys.

Description

The invention relates to piping systems, heat exchange equipment and is intended for manufacturers and operating organizations.

A known method for producing a hydrophilic polymer film and devices for its implementation, described in RF patent No. 2070211, IPC6 C08J 7/18, published on 12/10/1996, the Method consists in obtaining hydrophilic polymer films by radical grafting of the acrylic monomer on the surface and subsequent multi-stage processing .

However, this method is characterized by the complexity of the implementation, significant energy costs (high-frequency treatment, UV irradiation, air drying, the use of a complex of chemical solvents) and the inability to sell on large and operating products.

Closest to the technical nature of the invention is a method of reducing the hydraulic resistance of pipeline networks for transporting liquid media, providing the formation of a molecular coating on the surfaces of metal and alloy products, described in RF patent No. 2318140, IPC F15B 1/06, publ. 02/27/2008. The method consists in forming a molecular structured film on the surfaces of pipelines and equipment by introducing surfactants into a liquid medium, before entering a surfactant, an emulsion saturated with these molecules is prepared, the prepared emulsion is dosed into a liquid medium. In this case, the total thickness of the layers formed on the surfaces of the equipment of the pipeline network is commensurate with the surface roughness; biologically and thermally degradable compounds chemically inert with respect to the transported media are used as surfactants.

However, this method not only does not improve the heat transfer characteristics of the functional surfaces, but even with significant thicknesses, deterioration is observed, while there are a number of problems of heat and power equipment, the solution of which requires the intensification of heat transfer processes.

The technical result of the invention is to improve the hydrodynamic and thermodynamic characteristics of the surfaces of metal and alloy products.

This technical result is achieved by the fact that the known method of forming a molecular coating on the surfaces of metal and alloy products, which consists in forming a structured film on the surfaces by creating an emulsion of surface-active substances (surfactants), dosing the emulsion in a liquid medium, using surfactants biologically and thermally non-degradable compounds chemically inert with respect to liquid media, for example film-forming amines, characterized in that they heat the medium to a temperature above the melting temperature of the used surfactants, they clean the products from corrosion products and deposits, place the product in a liquid medium, create an electromagnetic field by introducing an electrode into the liquid medium, connect the electrode to one pole of the current source, and the metal or alloy product to the other, withstand the temperature and electromagnetic field until the formation of the molecular coating.

The method of forming a molecular coating on the surfaces of metal and alloy products is as follows.

The surfaces of metal and alloy products are cleaned of deposits and corrosion products. An emulsion of surfactant molecules is prepared in a liquid medium. Place the product of metal or alloys in a liquid medium and provide mixing. The liquid medium is heated to a temperature above the melting point of the surfactants used, for example for film-forming amines to a temperature above 70 ° C. An electrode is placed in the liquid medium, which is connected to the current source, the second electrode is the product itself, which is also connected to the current source. Surfactant molecules, for example, film-forming amines, are characterized by a dipole structure, which makes it possible to control the speed and direction of movement of molecules by an electromagnetic field. It is known that in the absence of an electromagnetic field, surfactant molecules are sorbed on the surface of metal or alloy products by a positively charged half to the surface, and negatively charged from the surface. Moreover, the formed ordered, structured, molecular, film layers are characterized by hydrophobic properties (contact angle of about 120 °). In the case of the appearance of an electromagnetic field in the direction from the surface of the product (in this case, a positive charge is applied to the electrode located in a liquid medium and a negative charge to the product), the surfactant molecules are reoriented and adsorbed by the negative half to the surface, and positively charged from the surface. In this case, the formed ordered, structured, molecular, film layers are characterized by hydrophilic properties (contact angle ≤20 °). After turning off the electromagnetic field, surfactant molecules are held on the surface by intermolecular interaction forces.

When creating an electromagnetic field to the surface of the product (in this case, a negative charge is applied to the electrode, and a positive charge is applied to the product), the formed ordered, structured, molecular, film layers of surfactants are characterized by an ultrahigh degree of wettability (contact angle ≥150 °).

Throughout the formation of ordered, structured, molecular, film layers in a liquid medium, a stable concentration of surfactant molecules and temperature are maintained.

The thickness of the molecular coating depends on the exposure time of the product in a liquid medium.

The formation of both ultrahydrophobic (wetting angle ≥150 °) and hydrophilic coatings (wetting angle ≤20 °) leads to the intensification of heat transfer processes. The mechanisms of the influence of coatings on heat transfer characteristics are different, in the first case, the mixing of the surface liquid layer is intensified due to changes in the flow hydrodynamics, and in the second case, due to an increase in the area of contact of the liquid with the surface.

The use of the invention provides an improvement in the hydrodynamic and thermodynamic characteristics of the surfaces of metal and alloy products.

Claims (1)

The method of forming a molecular coating on the surfaces of metal and alloy products, which consists in forming a surface-active film (surfactant) emulsion on the surfaces of a structured film, dosing the emulsion into a liquid medium, while chemically and biodegradable compounds are used as surfactants, chemically inert with respect to liquid media, for example, film-forming amines, characterized in that the medium is heated to a temperature above the melting point Surfactants clean products from corrosion products and deposits, place the product in a liquid medium, create an electromagnetic field by introducing an electrode into the liquid medium, connect the electrode to one pole of the current source, and the metal or alloy product to the other, withstand the temperature and electromagnetic field up to the completion of the molecular coating formation process.