WO2017142431A1

WO2017142431A1 - Method for protecting technological equipment used in petrochemical production

Info

Publication number: WO2017142431A1
Application number: PCT/RU2016/000079
Authority: WO
Inventors: Лев Христофорович БАЛДАЕВ; Раиса Дмитриевна БАКАЕВА; Динар Зуфарович ИШМУХАМЕТОВ; Максим Викторович ЕРШОВ; Вадим Сергеевич ШАРЫГИН; Александр Геннадиевич АЛЕКСАНДРОВ; Владимир Вячеславович КАМИНСКИЙ; Игнат Михайлович СТАРШОВ
Original assignee: Общество с ограниченной ответственностью "Технологические системы защитных покрытий"
Priority date: 2016-02-15
Filing date: 2016-02-16
Publication date: 2017-08-24
Also published as: RU2636211C2; RU2016104929A

Abstract

The invention relates to the field of applying coatings and may be used for protecting petrochemical equipment from the effects of corrosive media. A method involves shot-blasting the surface of a component prior to applying a coating of iron-based or nickel-based doped alloys, feeding the material to be applied into a burner which is affixed in a manipulator mechanism rotating along a 360° trajectory, and using a high-speed gas-thermal spraying method for forming, via the motion of the burner, either a single-layer functional coating having a thickness of 410+10 micrometers, or a multi-layer functional coating having a thickness of 410+10 micrometers with an adhesive layer of 200 micrometers, wherein, during the coating application process, an optimal application mode is selected by monitoring the pressure in a combustion chamber, the consumption of oxidizing agent and fuel, and indicators of the degree of excess oxidizing agent. The invention allows for increasing the corrosion resistance and wear resistance of equipment.

Description

The method of protection of petrochemical processing equipment

production

FIELD OF THE INVENTION

The invention relates to the field of chemical, petrochemical, oil refining engineering and can be used to protect the main and auxiliary equipment of these industries from aggressive corrosive environments, as well as environments that may additionally contain abrasive particles, rust, solid by-products of production, or additional hydrodynamic phenomena in the form of cavitation, water hammer.

State of the art

The prior art widely known methods of applying various kinds of powders in one or more layers by thermal spraying (see, for example, [1] US6503290, IPC B22F1 / 00, C22C1 / 04, publ. 07.01.2003; [2] US6749894, IPC C23C26 / 00, published on June 15, 2004).

The disadvantages of the analogue [1] are the limited applicability under the influence of corrosive media, which is due to the high hardness of the coating material (low ductility), which during operation (temperature drops, pressure drops of the medium) will contribute to cracking of the material with subsequent peeling from the base.

The disadvantages of the analogue [2] is the limited use (mainly titanium alloys), as well as the high cost of the starting material as a base (nickel and cobalt) for the subsequent filler in the form of ceramics. To give protection against high-temperature corrosion (mainly gas), the composition of the base base is also alloyed with expensive alloying elements, which ultimately affects the cost of the final solution.

Disclosure of invention

The objective of the invention is to increase the resource of the internal surfaces (volumes) of technological equipment subjected to corrosion-abrasive wear under the influence of an aggressive environment in the process operation (corrosive components: chlorides, hydrogen sulfide, mercaptans, side reaction products, etc.; as well as solid abrasive impurities: rust, particles of the catalyst complex, particles of deposits on the inner walls).

The technical result of the invention is to increase the energy efficiency of production processes for the production and processing of oil and gas, chemistry and petrochemicals, and more specifically, to increase the protection of metal-intensive equipment (reactors, columns); in increasing adhesion to the base material; in increasing the corrosion-mechanical properties: wear resistance, abrasion resistance, corrosion resistance, reliability - compared with the base material; in reducing the costs of enterprises for the maintenance and maintenance of large equipment (reactors, columns, etc.) involved in the extraction and processing of raw materials (oil and its derivatives).

The technical result is achieved due to the claimed method of protecting technological petrochemical equipment, which consists in the formation on the surface of a part of a single-layer or heterogeneous multilayer functional coating by high-speed thermal spraying, including:

· Activation of the surface of the part before application due to the mechanical effect of accelerated abrasive particles during abrasive blasting;

• supply of the applied coating material to the burner, mounted on a manipulator rotating 360 degrees;

· The formation of a single-layer functional coating, thickness

410 ± 10 μm, by coating during movement of the burner,

or

the formation of a heterogeneous multilayer functional coating, 410 ± 10 μm thick, by layer-by-layer coating during the movement of the burner, while the thickness of the functional layer providing increased adhesion to the base material is not more than 200 μm; • control of the spraying mode with the help of measuring equipment providing pressure control in the combustion chamber, oxidizer and fuel consumption, an indicator of the degree of oxidizer excess;

• the choice of the optimal mode of application of the coating material 5 is carried out both by the structural factor and gas permeability in the helium atmosphere.

The coating material is iron (Fe) or nickel (Ni) base alloyed with chromium (Cr), nickel (Ni), iron (Fe), cobalt (Co), carbon (C), manganese (Mn), molybdenum (Mo), tungsten (W), boron (B), silicon w (Si), niobium (Nb), titanium ( ^~ P). The functional layer of the multilayer functional coating is a material with a chemical composition that provides resistance to local and general corrosion processes (chromium equivalent Cr _{eq is} not less than 19, PREN within 20-65, carbon equivalent C _eq not more than 0.05%).

15 The implementation of the invention

Under the main technological equipment should be understood equipment involved directly in the production or processing of raw materials (oil, gas or chemistry). This includes reactors, columns, separators, heat exchangers, that is, equipment that directly

20 interacts (in contact) with the environment. Auxiliary equipment should be understood as equipment involved in preparatory and transportation operations with raw materials, for example, pumping equipment, raw materials tanks, pipes.

Since the result is aimed at protecting metal-intensive equipment, then

25 the most aggressive environment is inside the apparatus, only external factors act outside (atmospheric corrosion from gases, impurities, precipitation, etc.).

A functional coating is applied to the inner surface of the processing equipment by thermal spraying methods. Functionality is the set of properties that a coating can provide, for example, it can only be corrosion-resistant and can not work well when abrasive is affected; or it can be corrosion-resistant and wear-resistant and resistant to cavitation, etc. Since the environment in the column equipment in different parts in different state of aggregation, for example, at the bottom of the column is the liquid phase; at the top is gaseous, then different processes can be implemented in different zones by their nature (cavitation, general or local corrosion, etc.). Therefore, the composition and functional properties of the coating (corrosion resistance, wear resistance, cavitation resistance, etc.) vary depending on the operating conditions of the process equipment, the aggressiveness of the ongoing corrosion-mechanical processes, their localization, the type of thermal spraying technology used.

Nickel and iron are considered as the base material, which are subsequently alloyed with elements such as Cr, Ni, C, Mn, Mo, W, B, Si, Nb, Ti, to provide high resistance to local types of corrosion in the form of pits and ulcers, structurally stable for the temperature range of operation of technological equipment, as well as the rate of general corrosion of not more than 0.1 mm / year. Alloying elements such as Ni, Mn, C, Cr, can significantly increase the corrosion resistance of the material. Modification with boron, silicon, together with carbon, molybdenum improves the high-temperature structural stability of the material, promotes the formation of finely dispersed carbide and other hardening phases, which also betrays the material wear and abrasion resistance. The increase in carbon content is limited in view of the fact that, with its significant amount, stable carbides are released along grain boundaries with the main alloying elements Cr, Mo, Si, B, and thereby the elastic-plastic and corrosion properties of the solid solution are reduced due to depletion.

For technological equipment subjected to significant corrosion of internal surfaces (corrosion rate is higher than design), the coating is applied using a mobile complex of high-speed flame spraying, which allows the coating process both in the field (for example, on the customer's premises) and in the workshop ( production).

High-speed gas-flame application provides the formation of a dense continuous corrosion-resistant coating (without through porosity). At the same time, to ensure the quality of the coating, spraying can be carried out automatically using an industrial manipulator of the original design. The design of the manipulator depends on the version (equipment of horizontal or vertical type according to spatial arrangement) of technological equipment and its geometric dimensions of the internal space. The originality of the design of the manipulator lies in the possibility of coating without stopping along the set 5 path of the burner and rotating 360 degrees, which does not require intermediate stops when applying the coating in order to move the manipulator from the treated coated area to the area requiring treatment (spraying). The use of an automated application process allows us to ensure the repeatability of the coating properties and layer thicknesses in several different areas of the applied coating, which generally affects the operational reliability of the coating.

For the rest of the technological equipment, when the corrosion rate is at the design level, the equipment configuration does not allow the use of automated manipulators (the presence of support beams or elements

15 designs that interfere with the application process, which requires frequent stops (permutations of the manipulator)) the coating can be carried out using high-performance manual burners for thermal spraying. At the same time, the quality of the coating is ensured through the use of instrumentation at various stages of the process

20 gas flow meters for a stable supply of fuel and an oxidizing agent and providing the required type of flame, compressed air, a controlled device for delivering applied material, a laser range finder and other control and measuring devices).

Automated complex ensures stability

25 of the coating process (uniformity of coating thickness, coating density, etc.), this, accordingly, affects the operational resistance of the coating material (including corrosion resistance).

The use of manual burners is necessary in the case where there is no possibility of using automated complexes with manipulators. At the same time, manual labor will affect the conditions for the formation of the coating and its properties, therefore, to use this method, the use of control and measuring tools is necessary. Without the availability of control and measuring tools, there is no way to ensure the stability of the set parameters of the equipment. The formation of a dense coating (without through porosity), with increased corrosion and abrasion resistance, is ensured by the method of high-speed flame spraying. The applied coating material 5 is fed into the burner mounted on the manipulator. Layering of the coating to the required thickness is carried out in the process of movement of the burner mounted on the manipulator, rotating 360 degrees. At the same time, varying the composition of the starting material reduces the rate of corrosion-mechanical wear of technological equipment depending on its functional purpose and the corrosiveness of the medium. For environments promoting the active development of pitting and ulcers in the composition of the material, an increased Mo value is provided, while the PREN (equivalent number of resistance to pitting corrosion) should be in the range of 20-65.

15 Layer-by-layer coating allows the formation of both a single-layer functional coating, 410 ± 10 μm thick (mainly corrosion-resistant), and a heterogeneous multi-layer functional coating, also 410 ± 10 μm thick, where each layer has its own function (adhesive component + corrosion resistance)

20 or adhesive component + corrosion and abrasion resistance), while the thickness of the functional layer providing increased adhesion to the base material is not more than 200 microns. The coating material has an iron (Fe) or nickel (Ni) base alloyed with chromium (Cr), nickel (Νί), iron (Fe), cobalt (Co), carbon (C), manganese (Mn), molybdenum (Mo),

25 tungsten (W), boron (B), silicon (Si), niobium (Nb), titanium (Ti).

The functional layer of the multilayer functional coating is a material with a chemical composition that provides resistance to local and general corrosion processes (chromium equivalent Cr _{eq is} not less than 19, PREN within 20-65, carbon equivalent C _eq not more than 0.05%).

ЗО Directly choosing the optimal application mode (pressure in the combustion chamber of the burner at least 3 MPa; excess oxidizer 0.6-1; gas tightness up to 8-10 atmospheres when tested with helium, visible porosity no more than 1%) of the selected coating material on the equipment structural criterion and gas permeability. Optimal mode is a complex parameter, and for each material it can be different. Moreover, for some operating conditions of operation of column equipment (medium, temperature, pressure) this is one type of mode, for others it is another.

The structural criterion ensures the minimization of the content of defects in

5 coating (pores, cracks), as well as the amount of oxides. As is known, the presence of oxides in the coating structure leads to a significant increase in the electrochemical heterogeneity of the coating material, which negatively affects its corrosion resistance.

After structural optimization, gas permeability is checked (or optimization by gas permeability with adjustment of spraying conditions, provided that the same level of oxides and structural defects are selected during structural optimization). Gas permeability testing is carried out using an inert gas - helium, which is supplied under pressure. Test Helium Pressure

15 is selected based on the operating conditions of operation of technological equipment (operating pressure of technological equipment) and the subsequent increase in margin of 2-3 atmospheres. For critical process equipment, the test pressure reaches 8-10 helium atmospheres. Operating conditions for equipment include

20 the influence of temperature from 60 or more degrees, pressure (measurement in MPa) from below atmospheric and more, and also the environment (gas, liquid or mixed). For each technological equipment, operating conditions can be different (pressure, temperature, environment), vary within certain limits (design), under which the optimal flow of chemical,

25 physical and mechanical reactions that ensure the release of the final product (intermediate).

High adhesion to the base material of technological equipment is achieved by optimally varying the combustion parameters of the fuel mixture (pressure in the combustion chamber of the burner is at least 3 MPa, the degree of excess of oxidizing agent is 0.6-1), supplied to the burner, the quality of the surface preparation by the equipment before coating as well as the design of a high-speed burner, which allows you to control the speed and temperature of the particles. For technological equipment, where it is possible to use exclusively manual high-performance burners for gas-thermal spraying of coatings, selection and optimization of modes is also carried out according to the structural criterion and gas permeability. At the same time, the quality of the coating is ensured by the use of control and measuring tools at various stages of the process (controlled gas flow meters for stable supply of fuel and an oxidizing agent and providing the required type of flame, compressed air, controlled device for supplying applied material, a laser rangefinder and other control and measuring devices) .

Thus, the solution provides an increase in the resource of internal surfaces (volumes) of technological equipment subjected to corrosion-abrasive wear under the influence of an aggressive environment during operation.

Increasing the resource of the internal surfaces of vertical cylindrical technological equipment subjected to corrosion-abrasive wear under the influence of an aggressive environment during operation (corrosive components: chlorides, hydrogen sulfide, mercaptans, side reaction products, etc.; as well as solid abrasive impurities: rust, catalyst particles complex, particles of deposits on the inner walls) is achieved through the use of technology of high-speed flame spraying of the coating material with chemical composition providing resistance to local and general corrosion processes (chromium equivalent Cg _eq no less than 19, PREN within 20-65, carbon equivalent C _eq no more than 0.05). In this case, the selection of the coating material is carried out due to a preliminary analysis of the operating conditions of the technological equipment, as well as the aggressiveness of the ongoing corrosion processes (corrosion-mechanical wear) during operation.

Claims

CLAIM

1. The method of protection of technological petrochemical equipment, which consists in the formation on the surface of a part of a single-layer or heterogeneous multilayer functional coating by

5 high-speed thermal spraying, including:

• activation of the surface of the part before application due to the mechanical effect of accelerated abrasive particles during abrasive blasting;

• supply of the applied coating material to the burner, mounted on the manipulator, rotating 360 degrees;

• the formation of a single-layer functional coating, 410 ± 10 μm thick, by coating when the burner is moving,

or

the formation of a heterogeneous multilayer functional coating, 15 with a thickness of 410 + 10 μm, by layer-by-layer coating during the movement of the burner, while the thickness of the functional layer providing increased adhesion to the base material is not more than 200 μm;

• control of the spraying mode using the control and measuring equipment 20, which provides control of the pressure in the combustion chamber, the consumption of oxidizer and fuel, an indicator of the degree of excess of oxidizer;

• the choice of the optimal mode of deposition of the coating material is carried out both by the structural factor and gas permeability in the helium atmosphere.

2. The method according to p. 1, characterized in that the coating material has 25 iron (Fe) or nickel (Ni) base alloyed with chromium (Cr), nickel (Ni), iron (Fe), cobalt (Co), carbon (C ), manganese (Mn), molybdenum (Mo), tungsten (W), boron (B), silicon (Si), niobium (Nb), titanium (Ti).

3. The method according to p. 1, characterized in that the functional layer of the multilayer functional coating is a material with a chemical composition providing resistance to local and general corrosion processes (chromium equivalent Cr Cr _eq not less than 19, PREN within 20-65, carbon equivalent C _EC in not more than 0.05%).