Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H9/00—Details
  • F24H9/0052—Details for air heaters
  • F24H9/0057—Guiding means
  • F24H9/0063—Guiding means in air channels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/16—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed
  • B05B7/1606—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed the spraying of the material involving the use of an atomising fluid, e.g. air
  • B05B7/1613—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed the spraying of the material involving the use of an atomising fluid, e.g. air comprising means for heating the atomising fluid before mixing with the material to be sprayed
• • 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
  • C23C24/00—Coating starting from inorganic powder
  • C23C24/02—Coating starting from inorganic powder by application of pressure only
  • C23C24/04—Impact or kinetic deposition of particles
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H3/00—Air heaters
  • F24H3/02—Air heaters with forced circulation
  • F24H3/04—Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element
  • F24H3/0405—Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element using electric energy supply, e.g. the heating medium being a resistive element; Heating by direct contact, i.e. with resistive elements, electrodes and fins being bonded together without additional element in-between
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H9/00—Details
  • F24H9/02—Casings; Cover lids; Ornamental panels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/14—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas designed for spraying particulate materials
  • B05B7/1481—Spray pistols or apparatus for discharging particulate material
  • B05B7/1486—Spray pistols or apparatus for discharging particulate material for spraying particulate material in dry state

Definitions

• the invention relates to a device for high-pressure gas heating with a pressure vessel (1) through which gas flows, a heating element (3) arranged in the pressure vessel (1) and an insulation (2) arranged on the inner wall of the pressure vessel (1).
• the invention relates to a coating apparatus for substrate materials with a pressure vessel through which a gas flows, a heating element arranged in the pressure vessel and an insulation.
• gas with high pressure is necessary.
• the gas can be passed through a pressure vessel in which a heating element takes place.
• the pressure vessel is thus subjected to high temperatures and pressures from the inside. If the temperature can have a direct impact on the pressure vessel, expensive or difficult-to-process high-temperature materials need to be used, or
• Pressure vessel is relatively heavy due to its size and the necessary wall thicknesses. A heater with such a pressure vessel is difficult to handle because of the high weight and has a high thermal inertia. The heat dissipation via the pressure vessel leads to losses in the heat output.
• a device for coating substrate materials by thermal spraying can be sprayed with the powder particles.
• the device for coating substrate materials comprises a device for heating the gas, which in one embodiment comprises an electrical resistance heater.
• the device for heating the gas is arranged after a gas buffer container. It is also known from the document to isolate hot gas leading lines.
• a disadvantage of this prior art is that the device for heating the gas requires a pressure vessel, which is relatively heavy because of its temperature resistance and, when it is attached to a spray gun, prevents the operation of the spray gun. Due to the necessary large material thicknesses of the pressure vessel, this is also thermally inert.
• FR 2568672 includes a method of gas heating in which the gas is heated in a container having internal insulation.
• No. 5,963,709 discloses a hot-type heater which has an inner insulation and in which a porous foam ceramic is installed before and after the heating element, which ensures that the gas remains in the region of the heating element for a sufficiently long time.
• a device for high-pressure gas heating comprising a pressure vessel through which a gas flows, a heating element arranged in the pressure vessel and an insulation which is arranged on the inner wall of the pressure vessel, the pressure vessel being designed for pressures of 15 to 100 bar is and in an inflow region of the pressure vessel, at least one flow distribution element is arranged, which distributes the inflowing gas over the entire width of the heating element.
• the apparatus for high-pressure gas heating gives gas with gas outlet temperatures of 100 to 1100 0 C, preferably from 700 to 900 0 C. Especially in the upper
• Temperature range of said values only selected steels for a limited time or special high temperature materials can be used, otherwise there is a softening of the material and a deformation due to creep and only a very low creep strength of most materials is given. Since the device for high-pressure gas heating gas heated from a pressure of 15 to 100 bar, in particular in the range of 25 to 60 bar, a large amount of energy is transferred from the high-tension gas to the wall of the pressure vessel. By carrying out a device for high-pressure gas heating, the energy transfer to the wall of the pressure vessel is reduced by the internally arranged insulation.
• the temperature of the pressure vessel to the hot gas to 60% of the hot gas temperature, preferably less than 40% and with appropriate design less than 20% of the temperature of the hot gas reduced, measured in 0 C.
• temperatures of the pressure vessel of below 22O 0 C, at For example, steel does not show any significant reduction in its strength.
• the pressure vessel can therefore be designed with a significantly lower wall thickness and is lighter, so that the device for high-pressure gas heating can also be integrated into a spray gun. Due to the reduced heat transfer to the pressure vessel, the device for high-pressure gas heating is not thermally inert and reacts quickly when the temperature of the gas is to be changed.
• the insulating material used has a thermal conductivity of less than 4 W / (m * K), preferably less than 2 W / (m * K) and if the insulation is designed such that less than 300 W. / (m 2 * K), preferably less than 150 W / (m 2 * K), more preferably less than 75 W / (m 2 * K) are delivered to the pressure vessel.
• a flow distribution element is arranged in the inflow region of the pressure vessel, which distributes the inflowing gas over the entire width of the heating element.
• Highly compressed gas has a high density and at the same flow cross section and same mass flow compared to non-compressed gas, a significantly lower flow velocity. Therefore, when using compressed gas under otherwise identical conditions, the flow resistance is significantly lower and the driving force for a uniform distribution of the gas over the entire flow cross section is missing. In order to ensure a uniform flow of the heating element, therefore, the gas flow through the flow distribution element is distributed evenly over the cross section of the pressure vessel.
• At least one element for flow distribution is provided in addition to the inner insulation, which is advantageous so that a compact design and low weight is achieved, at least one element for flow distribution.
• the flow distribution element is used for gas distribution, which must be made active at the high pressures in the pressure vessel, so that an effective gas heating is possible.
• the flow element must be designed so that virtually no or at least only a slight pressure drop occurs on it.
• a pressure drop is in the preferred use in a coating device because of disadvantage, since in the spray gun in front of the nozzle as high a pressure as possible, so as to the highest possible in the expansion in the nozzle Gas speeds can be achieved.
• the flow distribution element is advantageously designed so that the pressure drop is less than a hundredth, preferably less than a two-hundredths of the applied gas pressure.
• the gas must be distributed very uniformly over the entire inlet region of the gas heater with the flow distribution element, since only with a careful gas distribution, a uniform flow through the heater is achieved. This in turn is necessary so that an effective heat transfer from the heater to the gas can take place and the desired high temperatures are achieved.
• the device according to the invention is very handy and lightweight, so that they can be easily mounted, for example, in a spray gun and thus perform the movements performed during thermal spraying with.
• power densities of 0.5 to 8 kW / kg, preferably 1 to 3 kW / kg based on the total high-pressure gas heater and power volume of 3 to 30 kW / l, preferably from 10 to 25 kW / l based on the internal volume of the pressure vessel reached.
• Bicone a perforated disc, a grid, guide plates and / or formed by a diverging inlet section.
• These flow distribution elements may be arranged individually or in combination of two or more elements in the inflow region.
• On the outer surfaces of cooling fins may be formed.
• the pressure vessel temperature is less than 600 0 C.
• the pressure vessel may for example consist of steel and / or titanium or a titanium alloy.
• pressure vessel temperature is reduced to below 600 ° C. by insulation and external heat dissipation, a pressure vessel with a significantly smaller wall thickness can be used when using a high-temperature material.
• pressure vessels made of steel, titanium or titanium alloy can be used. At these temperatures, these materials show no significant change in strength. If the pressure vessel temperature further reduced to below 400 0 C, there is a further significant reduction in weight.
• the pressure vessel temperature is less than 200 ° C.
• the pressure vessel may consist of aluminum or aluminum alloys.
• Aluminum is a not only lightweight, but also inexpensive construction possible.
• the heating element consists of electrical heating wires.
• a Filticianrhitzer is used.
• Such a heating element in the form of a so-called filament heater is electrically heated and advantageously produces no combustion residues.
• the heating wires are arranged in individual channels, wherein the gas to be heated flows through these channels. Many channels together eventually make the filament heater.
• the heating wires on power supplies which are resistant to heat and have heat-resistant passages through the wall of the pressure vessel.
• already heated gas can be supplied to the device for high-pressure gas heating, since the power supply lines do not have to be in a cold gas flow.
• the device forms a replaceable unit with easily detachable connections for the gas supply and gas discharge.
• the pressure vessel can be designed for pressures of 25 to 60 bar and the heating element, the gas to 700 0 C to 900 0 C heat.
• the device for high-pressure gas heating then works in favorable for cold gas spraying temperature and pressure ranges.
• Higher gas temperatures increase the speed of sound of the gas and thus the flow rate in a nozzle, e.g. a coating device. Particles are accelerated more and bounce at a higher speed on a substrate to be coated. Also, the particle temperature at impact is higher.
• the particle material is thermally softened and ductilised. Higher gas pressures lead to a higher gas density in the gas flow, and thus promote the acceleration of the particles, in particular the acceleration of coarser particles.
• Coarser particles (25 to 100 ⁇ m in diameter and up to 250 ⁇ m in diameter) are of great importance in order to produce high-quality coatings and to achieve high application rates.
• the object is also achieved by a coating device for
• Substrate materials in which at least one device for high pressure gas heating is present.
• One or more of the high-pressure gas-heating devices can be arranged in or on a spray gun and further can be arranged in a stationary part of the coating device, which are then connected in series via a hot gas hose to the spray gun.
• the stationary part of the Coating device can be used instead of the inventive device for high-pressure gas heating, another method for gas heating, as play in the stationary part of weight and manageability only a minor role.
• Fig. 1 shows schematically a device according to the invention as rotationally symmetrical
• Fig. 1 shows schematically a device according to the invention as a rotationally symmetrical component in longitudinal section, which is used in the present example in a coating apparatus for cold gas spraying.
• the pressure vessel 1 has on its inside an insulation 2.
• a heating element 3 is arranged, here in the form of a filament heater, which consists of a plurality of electrical heating wires.
• the gas to be heated is supplied to the pressure vessel 1 via a gas supply line 4.
• the pressure vessel 1 is a rotationally symmetrical body, in which a in the indicated by the arrows gas flow bicone 5 that
• the inventive device for high-pressure gas heating forms a standardized unit that is easily replaceable, z. B. in case of repair, or to arrange several consecutively.
• the heating element 3 can be configured as easily replaceable heating cartridge. As a result, the heating element 3 can be easily replaced in case of repair.
• the gas flows through the pressure vessel 1, wherein it is distributed uniformly over the cross section of the heating element 3 by the double cone 5, as shown by the arrows. Due to the internal insulation 2 is achieved that only a small amount of heat energy reaches the wall of the pressure vessel 1. About the
• the pressure vessel 1 can therefore be relatively thin-walled and lightweight.
• the device according to the invention reacts quickly and without delays.
• the mass of the pressure vessel can not delay because of the internally mounted insulation.
• the design of the device for high-pressure gas heating such as strength of the insulation, gas distribution, heating via heating wires allows for compact design and high power density reaching very high gas temperatures for a wide range of gas pressures.
• FIGS. 2 to 6 schematically show further embodiments of the flow distribution element of the device according to the invention of FIG. 1 in FIG.
• Fig. 2 Longitudinal section. Schematically illustrated is the front part of the pressure vessel 1 with the gas supply line 4.
• the flow distribution element in Fig. 2 consists of multiple lattices 8, in Fig. 3 of guide plates 9.
• a perforated disc 10 is arranged so that they causes a uniform gas distribution and in Fig. 5, the gas by a combination of double cone 5 and the
• Fig. 6 shows an embodiment in which the pressure vessel 1 in the region which adjoins directly to the gas supply line 4, is designed as a divergent inlet section 11.
• the double cone When using a double cone and another element, in particular a perforated diaphragm for flow distribution, the double cone causes a delay and a coarse distribution of the gas and the further element causes a fine distribution of the gas in the heating element.
• the high pressure gas heating apparatus of the present invention may also be used in other areas where high pressure gases must be heated, such as atomizing melts with hot gases. Also, for preheating filler material or base material during welding or soldering with arc, flame or laser device of the invention for high-pressure gas heating can be used with advantage. It is also possible to solder the gas stream which leaves the device according to the invention.
• the inventive device for high pressure gas heating allows a compact design with length to diameter ratios between 1 and 5 and high power densities of 1 to 8 kW / kg at a high power volume of eg 5 to 25 kW / l.
• the design of the device as a unit allows quick replacement of a defective high pressure gas heating device.
• particularly favorable impact temperatures of the sprayed cold spray particles between 200 and 600 0 C can be achieved with high impact speed by gas temperatures of 600 to 1100 0 C, in particular from 800 to 1100 0 C can be very flexibly selected.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Thermal Sciences (AREA)
• Physics & Mathematics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Nozzles (AREA)
• Pressure Vessels And Lids Thereof (AREA)
• Direct Air Heating By Heater Or Combustion Gas (AREA)

Priority Applications (3)

Applications Claiming Priority (4)

Publications (1)

Family

ID=36551042

Family Applications (1)

Country Status (5)

Cited By (5)

Families Citing this family (9)

Citations (6)

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• 2005
  • 2005-11-10 DE DE102005053731A patent/DE102005053731A1/de not_active Withdrawn
• 2006
  • 2006-01-05 EP EP06000207A patent/EP1785679A1/de not_active Withdrawn
  • 2006-11-09 US US12/091,942 patent/US8249439B2/en not_active Expired - Fee Related
  • 2006-11-09 JP JP2008539342A patent/JP5039049B2/ja not_active Expired - Fee Related
  • 2006-11-09 WO PCT/EP2006/010759 patent/WO2007054313A1/de not_active Ceased
  • 2006-11-09 EP EP06828986A patent/EP1946012A1/de not_active Withdrawn

Patent Citations (6)

Non-Patent Citations (1)

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