Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/18—Rotors
  • F04D29/22—Rotors specially for centrifugal pumps
  • F04D29/2261—Rotors specially for centrifugal pumps with special measures
  • F04D29/2294—Rotors specially for centrifugal pumps with special measures for protection, e.g. against abrasion
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
  • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
  • C23C28/32—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer
  • C23C28/321—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer with at least one metal alloy layer
  • C23C28/3215—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one pure metallic layer with at least one metal alloy layer at least one MCrAlX layer
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
  • C23C28/30—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer
  • C23C28/34—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates
  • C23C28/345—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer
  • C23C28/3455—Coatings combining at least one metallic layer and at least one inorganic non-metallic layer including at least one inorganic non-metallic material layer, e.g. metal carbide, nitride, boride, silicide layer and their mixtures, enamels, phosphates and sulphates with at least one oxide layer with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/02—Selection of particular materials
  • F04D29/026—Selection of particular materials especially adapted for liquid pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D7/00—Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts
  • F04D7/02—Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type
  • F04D7/06—Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type the fluids being hot or corrosive, e.g. liquid metals
  • F04D7/065—Pumps adapted for handling specific fluids, e.g. by selection of specific materials for pumps or pump parts of centrifugal type the fluids being hot or corrosive, e.g. liquid metals for liquid metal
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C15/00—Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants
  • G21C15/24—Promoting flow of the coolant
  • G21C15/243—Promoting flow of the coolant for liquids
  • G21C15/247—Promoting flow of the coolant for liquids for liquid metals
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21D—NUCLEAR POWER PLANT
  • G21D1/00—Details of nuclear power plant
  • G21D1/04—Pumping arrangements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2230/00—Manufacture
  • F05D2230/90—Coating; Surface treatment

Definitions

• the present disclosure relates to mechanical pumps for pumping hot, corrosive and erosive fluids like liquid metals and molten salts.
• the pumps can be of any construction or mechanism of operation, such as radial/centrifugal or axial, wherein at least one component is in contact with the liquid metal or molten salt.
• Ceramic pumps or ceramic impellers that may have excellent corrosion and erosion resistance are known in the art, for example through US 3,776,660 and US 6,019,576. Suggested ceramic materials include graphite and silicon carbide, as disclosed for example in US 5,586,863. However, ceramic materials are
• the fracture toughness of ceramic materials including graphite is generally considered to be too low for use as pump components.
• Electro magnetic pump technologies have received a lot of interest in the nuclear industry.
• the use of electro-magnetic pumps for liquid metals is disadvantageous due to their poor efficiency.
• the pumps have shown to be a critical component in such nuclear or solar power plants since the overall energy efficiency is dependent on the maximum allowed fluid temperature and flow rate.
• the maximum operating temperature and choice of fluid is basically limited by corrosion and erosion problems of the pump components.
• Temperatures of the liquid metals and molten salts used for energy production are typically in the range 200-500 °C but it is desirable to go higher in the future, possibly up to 800 °C.
• One object of the present disclosure is to provide a pump for hot and corrosive fluids wherein the pump has an extended service life.
• a particular object is to provide a pump for molten lead or lead bismuth eutectic (LBE) for use in nuclear reactors.
• LBE molten lead or lead bismuth eutectic
• a first aspect is a pump for pumping molten metal or molten salt, said pump comprising at least one component manufactured of a substrate and coated with one or more wear and erosion resistant surface layers, wherein said substrate is provided with at least one intermediate binding layer and one outer layer, and said outer layer comprises at least one refractory oxide.
• the thickness of the surface coating is 0.2 pm to 1000 pm.
• the thickness of the surface coating is 5 - 600 ⁇
• the intermediate binding layer comprises at least one layer of TiN, preferably having a thickness of 0.1 - 5 pm.
• the substrate is a cemented carbide and the refractory oxide outer layer comprises at least 90 % AI2O3.
• the outer layer comprises at least 99 % AI2O3.
• the cemented carbide comprises at least 80 % WC and a metallic binder, said metallic binder comprising at least one metal selected from the group of Co, Ni, Fe, Cr, Al, Mn, Mo, V, Ti, Ta, Zr and Nb.
• said metallic binder comprises Co and/or Fe and/or Ni and/or Cr and/or Mo in combination with Al.
• the binder is a Fe-AI, Ni-AI or a Ni-Cr-Mo-AI binder.
• a second aspect relates to a pump for pumping molten metal or molten salt, said pump comprising at least one component manufactured of a substrate and coated with one or more wear and erosion resistant surface layers, wherein said substrate is provided with at least one intermediate binding layer and one outer layer, and said outer layer comprises at least one refractory oxide, wherein the substrate is a nickel based alloy comprising at least 30 wt. % Ni, the outer layer comprises a refractory oxide based on Zr02, preferably yttria-stabilized zirconia (YSZ), and the intermediate metallic binding layer comprises at least of one metal selected from the group Fe, Ni, Co, Cr or AI.
• the thickness of the surface coating is 0.2 pm to 1000 pm.
• the thickness of the surface coating is preferably 5 - 600 pm.
• the present disclosure offers a solution to the shortcomings associated with mechanical pumps, mainly erosion and corrosion problems, when using high temperature fluids as energy carrier, energy storage and coolants for future energy production techniques as well as extending the service life time of pumps for the metallurgical industry etc.
• a metallic substrate a cermet or a cemented carbide substrate with a metallic binder phase which has good mechanical properties in combination with corrosion and erosion resistant coatings, which are sufficiently well matched regarding thermal expansion, thus enabling good coating adherence, it is possible to construct a mechanical pump for hot fluids with excellent service life time.
• the outer surface layer must be hard enough to possess good erosion resistance.
• oxides the better quality of alumina has 9 out of 10 on the Mohs hardness scale of abrasives and zirconia has a hardness of 8.
• Alumina and zirconia exhibit good corrosion resistance in for instance liquid lead and LBE. In general, these oxides are suitable for use when pumping a variety of different liquid metals and molten salts of technical interest.
• CSP concentrated solar power
• Examples of technically interesting salts include, but are not limited to, sodium and potassium nitrates (Na, K)N03 and lithium, sodium and potassium carbonates (Li,Na,K)C03.
• carbides and nitrides such as WC, TiC, B 4 C, SiC, TaC, ZrC, TiN, ZrN, BN and carbo-nitrides such as TiCN and TiAIN have a Mohs hardness of 8.5-9.8 and exhibit good erosion resistance and possess sufficiently good high temperature oxidation and corrosion resistance in most of the liquid metals and molten salts of interest for the different industrial applications.
• TiC and ZrC have been tested in liquid Pb, Na and Li around 800°C and showed good resistance.
• the adherence of such layers is generally not sufficient for pump components exposed to fluids with high flow rates.
• it is necessary to provide an additional outer oxide coating preferably based on alumina or zirconia.
• CSP concentrated solar power systems
• Yttria-stabilized zirconia could for example be used on iron and nickel base alloy substrates since these have more similar thermal expansion coefficients.
• Suitable techniques to apply YSZ or Thermal Barrier Coatings (TBC) on a metal substrate are Electron Beam Physical Vapor Deposition (EBPVD), Air Plasma Spray (APS), High Velocity Oxygen Fuel (HVOF), Electrostatic Spray
• EAVD Assisted Vapour Deposition
• Direct Vapor Deposition
• YSZ can also be applied directly on a metal substrate but the use of a metallic and/or oxide binding layer (bond coat) as an intermediate layer should be applied before the outer YSZ-layer is deposited.
• a metallic bond coat Fe- or Ni- based, should preferably contain chromium and some per cent aluminium in order to form a thin alumina scale for optimal adhesion of the outer YSZ-layer.
• inventions of the present disclosure comprises at least one component coated with one or more wear and erosion resistant surface layers.
• This component can be an impeller vane, an impeller or a part of or the entire inner surface of the pump housing.
• the impeller is he most important part since it is subjected to high flow rates.
• the substrate material may be selected from the following group of materials: steels, stainless steels, nickel-, cobalt-, molybdenum-, tantalum- and tungsten-based alloys, cermets and cemented carbides.
• a material of particular interest is tungsten carbide, which can be without a binder, or include a metallic binder.
• the binder can comprise at least on metal selected from the group of Co, Ni, Fe, Cr, Al, Mn, Mo V, Ti, Ta, Zr and Nb. According to a preferred embodiment the binder is chosen with respect to its stability in liquid lead and LBE at high
• the surface coating comprises at least one layer of oxides, nitrides and carbides or mixtures thereof, preferably the coating comprises at least two layers wherein the carbides and/or nitrides comprises at least one element selected from Zr, Ti, Ta, V, Hf, Nb, W, B, Mo, Cr, Al, and Si and/or the oxides comprises aluminium oxide and zirconium oxide and stabilized or doped oxides thereof.
• the total thickness of the surface coating is 0.2 pm to 1000 pm
• CVD coatings typically have a thickness of about 1 to about 20 pm and APS coatings typically have a thickness of about 50 to about 600 pm.
• the pump comprises an impeller or at least one impeller vane made of a nickel-based alloy provided with a coating comprising one outer layer of yttria stabilized zirconia (YSZ).
• YSZ yttria stabilized zirconia
• Another preferred embodiment comprises of an impeller or at least one impeller vane wherein the substrate is a cemented carbide and the coating
• the cemented carbide comprises at least 80 % WC and a metallic binder, the metallic binder comprising at least on metal selected from the group of Co, Ni, Fe, Cr, Al, Mn, Mo, V, Ti, Ta, Zr and Nb.
• the binder is chosen from Fe, Ni, Cr, Mo and Al, preferably the binder contains an amount of Al such that it easily can form aluminium oxide if the surface coating should be damaged.
• a particular use of the coated cemented carbide is the use as a structural material for at least one pump component in a pump for pumping liquid lead or LBE, in particular in a nuclear reactor, wherein the liquid lead or LBE has an oxygen concentration below the lead oxide formation limit.
• Another use is the pumping of molten salts, such as carbonate, nitrate and sulphate salts for use in energy applications such as CSP.
• a nickel-based alloy comprising an outer layer of yttria-stabilized zirconia (YSZ) is also a suitable material for the above uses.
• YSZ yttria-stabilized zirconia
• TBC Thermal barrier coating
• Air ingress was reduced to a minimum using standard vacuum copper sealing, and the amount of dissolved oxygen in the liquid lead was controlled by means of an Ar-H2-H20 gas mixture.
• the test samples were placed close to the periphery of the rotating disk, where the highest flow rates were expected.
• the facility was heated using a 1000 W band heater mounted on the outside of facility and the temperature was controlled using thermocouples of type K and a PID regulator.
• the test conditions are shown in Table 2.
• the screening test revealed large differences in erosion and corrosion resistance between the tested specimens.
• the uncoated steel samples 1 - 3 showed severe erosion and corrosion damage, meaning a noticeable shift in appearance from smooth metallic surfaces to dark uneven and notched surfaces.
• the least damage was found on the uncoated FeCrAI alloy, sample 3.
• Sample 6 the commercial Al 2 03-ceramic and sample 7, the YSZ coated Ni-base ally, were virtually unaffected.
• the screening test thus confirmed that structural components of a pump for liquid lead could be effectively protected from the bulk metal by stable coatings.
• Particular useful coatings comprise AI2O3 and Zr02.
• the screening test thus confirmed that structural components of a pump for liquid lead could be effectively protected from the bulk metal by stable coatings.
• Particular useful coatings comprise AI2O3 and Zr02. Pumps with such coatings or including components with such coatings are well suited for use in different systems for the generation of energy, such as but not limited to concentrated solar power and nuclear energy. They are particularly well suited for use in lead or LBE cooled reactors in the nuclear industry.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Inorganic Chemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Plasma & Fusion (AREA)
• High Energy & Nuclear Physics (AREA)
• Ceramic Engineering (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=60203147

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (6)

Citations (2)

Family Cites Families (7)

• 2017
  • 2017-05-04 CA CA3073562A patent/CA3073562C/en active Active
  • 2017-05-04 CN CN201780027621.0A patent/CN109072398A/zh active Pending
  • 2017-05-04 WO PCT/SE2017/050431 patent/WO2017192097A1/en unknown
  • 2017-05-04 EP EP17792958.5A patent/EP3452629B1/en active Active

Patent Citations (2)

Non-Patent Citations (8)

Also Published As

Similar Documents

Legal Events