Abstract: A reduction in tube to header joint failures in a heat exchanger having spaced headers (12,14), elongated, side-by-side parallel spaced tube slots (22) in the headers (12,14) along the length thereof and a plurality of flattened tubes (26) having ends (24) received in the tube slots (22) and metallurgically bonded to the header (12,14) thereat was achieved through the use of a reinforcing structure (38) having at least two projections (40) having a cross sectional shape complimentary to at least a part of the surface of the tubes (26) at their ends (24) and a length sufficient to extend along the tube ends (24) to a location past the metallurgical bonds between the tube ends (24) and a header (12,14), and a spine (44) extending transverse to the projection. Also disclosed is a reinforcing structure (38) and a method of reinforcing the tube to header joints in a heat exchanger.

Abstract: A method for manufacturing an aluminum heat exchanger includes the steps of: obtaining a heat exchanger tube 2 by forming a Zn thermally sprayed layer on a surface of an aluminum flat tube core so as to adjust Zn adhesion amount to 1 to 10 g/m2; obtaining a heat exchanger core by alternatively arranging the heat exchanger tube 2 and an aluminum fin 3 and brazing the heat exchanger tube and the fin with end portions of the heat exchanger tube connected to aluminum headers in fluid communication; and forming a chemical conversion treatment coat (corrosion resistance coat) on a surface of the heat exchanger core by subjecting the surface of the heat exchanger core to chemical conversion treatment using at least one chemical conversion treatment agent selected from the group consisting of phosphoric acid chromate, chromic acid chromate, phosphoric acid zirconium series, phosphoric acid titanium series, fluoridation zirconium series, and fluoridation titanium series.

Abstract: A process for the preparation of hydrogen and carbon monoxide containing gas from a gaseous hydrocarbon feedstock by performing the following steps: (a) partial oxidation of part of the feedstock thereby obtaining a first gaseous mixture of hydrogen and carbon monoxide; and, (b) catalytic steam reforming of part of the gaseous feedstock in a Convective Steam Reformer having a tubular reactor provided with one or more tubes containing a reforming catalyst, wherein the exterior of the tubes of the tubular reactor is used to cool the hot gas as obtained in step (a) and wherein the exterior of the tubes is a metal alloy surface having between 0 wt % and 20 wt % iron.

Abstract: The invention relates to shell-and-tube heat exchangers, including those used to cool cracking gas in petroleum refining, containing wear resistant tube plate linings. In the heat exchangers, at least a portion of the inlet tube plate is covered by wear-resistant inserts which can be at least partially inserted into the heat exchanger tubes.

Abstract: A corrosion-resistant alloy metal tube sheet used to construct a shell and tube heat exchanger (50) for cooling fluids with sea water passing through corrosion-resistant alloy tubes (25) contained in a horizontal carbon steel outer shell (1) that are supported and sealed at each end by passing them through holes (27, 30) in a carbon steel tube sheet (28, 31) and axially aligned holes (36, 37) in alloy tube sheets (34, 35) that cover and protect the adjacent interior carbon steel tube sheets from sea water corrosion. The walls of the holes (27, 30, 36, 37) have at least one annular groove (45, 46) and the ends of each tube are radially expanded to form circumferential ridges (40, 41) on the outside of each tube at a mating location with each of said annular grooves (45, 46) where they are forcibly driven into the grooves to form a circumferential joint having good mechanical strength and water tightness, thereby eliminating the need for welding the external joint between the alloy tube sheets and alloy tubes.

Abstract: A vertical heat exchanger is described, which allows efficient elimination of the gas generated therein and efficient removal of the sludge accumulated therein. The vertical heat exchanger has at least part of one end of a vent pipe formed of an upper tube sheet part (an upper cover part in the case of a spiral heat exchanger) and the other end thereof connected outside the heat exchanger to an immediately adjacent fluid passing port passing the same fluid as the vent and/or at least part of one end of a drain pipe formed of a lower tube sheet part (a lower cover part in the case of a spiral heat exchanger) and the other end thereof connected outside the heat exchanger to an immediately adjacent fluid passing port passing the same fluid as the drain.

Abstract: A tube shield assembly for protecting tubes includes a guard, a securing member and a holding tooth, wherein welding is not required to secure the guard to the tube. The guard is axially elongated and can have a semi-cylindrical cross-section to define a main body portion. The securing member includes at least one pair of fastening clips to secure the guard to the tube. The fastening clips permit radial expansion and contraction of the tube and the tube shield assembly in response to, for example, temperature fluctuations. The holding tooth is a tooth-like protrusion between the tube shield assembly and the tube to which it is secured to prevent axial slippage of the tube shield assembly up or down the length of the tube.

Abstract: A method of surface treating an aluminum alloy base body of an heat exchanger which method enables an etching procedure to be carried out uniformly and quickly and a corrosion-resistant chemical conversion coating to be formed, is effected by pretreating the Al heat exchanger base body with an aqueous pre-treating liquid having a pH of 9.0 or less, etching the pretreated base body with an aqueous alkaline solution having a pH of 9.0 or more, and then subjecting the etched base body to a chemical conversion treatment or a hydrophilicity-enhancing treatment.

Abstract: A heat exchanger uses a skeleton forming of a lattice of first and second bars to provide a box-like structure. Blocking bars are arranged between gaps in the first and second bars to provide a blocking surface to divert airflow around a portion of the heat exchanger core. A brazing material is used in the assembly of the core and the skeleton, which includes the blocking bars.

Abstract: A heat exchanger assembly for an automotive vehicle includes at least one tube having an internal layer and an external layer. The external layer is an aluminum based material, and the internal layer is a stainless steel based material. At least one turbulator is disposed inside the tube and is formed of a stainless steel based material.

Abstract: A water-cooled air conditioner and a method controlling the same are provided. The water-cooled air conditioner includes a first heat exchanger where indoor air is heat-exchanged with refrigerant, a compressor for compressing the refrigerant, a plate-shaped second heat exchanger where the refrigerant compressed by the compressor is heat-exchanged with the water, and a freeze-crack preventing unit that is provided at a side of the second heat exchanger to prevent the water in the second heat exchanger from freezing.

Abstract: A solar collector plate (2) has a solar radiation receiving front absorber plane (3) that is wiped at its rear side by a cooling liquid (4) flowing in channels (5). Cavities (7), preferably behind the channels (5) and integrated in the solar collector plate (2), and that can be closed off by the very liquid flow (4), provide a closed air volume that gives a dampening effect regarding kickbacks and pressure transients in the liquid (4).

Abstract: A heat exchanger has tubes stacked in a direction and constructed of plate members. Each tube includes a main part for defining a passage of an internal fluid therein and a joined part that is provided by joining portions of the plate member to have surface contact. The joined part projects from an upstream end of the main part with respect to a flow of an external fluid. The joined part includes an inclined portion that is bent at a predetermined angle relative to a reference plane that is perpendicular to the direction in which the tubes are stacked.

Abstract: A fin and tube assembly for use in a heat exchanger comprising a carbon steel tube, a carbon steel fin, and an external brazing compound comprising a material selected from the group consisting of nickel, chrome, copper, aluminum, zinc, and graphite brazed to the tube and fin is disclosed. A method for making the assembly and a power plant which includes the assembly are also disclosed. The brazing compound functions to prevent corrosion of the carbon steel and also functions to attach the tube and fin together.

Abstract: The subject invention pertains to a method and apparatus for heating exchanging. In various embodiments, the application of coating, plating, soldering, and brazing technologies can be used to create high performance heat exchangers. Specific embodiments of the subject heat exchanger can be lightweight and resistant or impervious to oxidation and/or corrosion. Specific embodiments of the subject heat exchanger can be highly manufacturable. Embodiments of the subject invention are directed to a heat exchanger that includes primarily, but not necessarily entirely, components or assemblies that are made from aluminum and/or aluminum alloys, and are coated or plated with a more oxidation and/or corrosion resistant metal. The coated or plated aluminum components or assemblies can be specifically resistant to corrosion or oxidation in the presence of water or water based solutions and mixtures.

Abstract: A bank of horizontally oriented boiler tubes which are periodically exposed to the abrasive action of a stream of blowing fluid cleaning medium. Portions of the boiler tubes, located at the top of the bank, are provided with spaced shields for protection from the fluid cleaning medium. An anti-vibration bar extends vertically between the protective shields to suppress vibration of the boiler tubes. A cap is fitted over the top end of the anti-vibration bar. The cap is sized to overlap adjacent portions of the protective shields thereby covering any gaps between the anti-vibration bar and the shields that would expose the boiler tubes to the action of the fluid cleaning medium.

Abstract: A snow melting panel has a piping arrangement that includes straight pipe lines and U-shaped bend sections is provided. The panel can be sized such that the parallel length of the straight pipe lines is 300 to 5000 mm, and the perpendicular span of the straight pipe lines is 100 to 4000 mm. The piping arrangement may have a hot-dip galvanized layer or a highly corrosion resistant galvanized layer formed or provided only on the outer surface of the piping arrangement. For example, the gap between adjacent pipes in the straight pipe lines is 100 to 300 mm. In addition, the straight pipe lines and the bend sections can be made from a single long pipe. The piping arrangement may be made from a steel pipe with a silicon content of less than 0.05 wt %, or not less than 0.15 wt % and not more than 0.20 wt %.

Abstract: A heat exchanger for cooling a hot gas that contains solid particles, comprising heat exchanger tubes through which the hot gas flows, with the tubes being surrounded by a casing, and with ends of the tubes being welded, via weld seams, into bores of respective tube plates disposed at the ends of the casing. A protective layer coats the end face of the gas inlet side tube plate, an inner wall of the bores, the weld seams, and an inlet region of the heat exchanger tubes. The protective layer comprises a metallic adhesive layer, a high temperature and erosion resistant ceramic layer, and a high temperature and erosion resistant metal layer disposed between the adhesive layer and the ceramic layer.

Abstract: To protect a plate-type heat exchanger (1) against corrosion due to the attack of sulfuric acid, it is proposed in accordance with the invention that the region through which flows sulfuric acid has at least one metal cathode (16, 17) and one reference electrode (27), that at least half the metal plates (7) have an electric contact (23) which is connected with the anode (21) of an electric d.c. voltage source of variable electric voltage, that the metal cathode (16, 17) likewise is electrically connected with the d.c. voltage source, and that the d.c. voltage source belongs to a potentiostat (20) which is electrically connected with the reference electrode (27).

Abstract: A heat exchanger, in particular an exhaust gas heat exchanger for a motor vehicle, has tubes through which a first fluid can flow and around which a second fluid can flow, and a headpiece. The headpiece includes a dual-walls structure in at least a part thereof and a distribution chamber that communicates with the tubes.

Abstract: A cooling arrangement for an offshore wind energy installation, having a heat-absorbing device for absorbing heat generated by the electronic devices and/or the mechanical devices of the offshore energy installation, which is to be removed, and a coupled heat-dissipating device for dissipating heat to the surrounding water. The heat-absorbing device has a first cooling circuit operated by a fluid coolant which, in a heat exchanger device, transfers the absorbed heat to the heat-dissipating device having an open second cooling circuit operated with the ambient water as the coolant. A plurality of electrodes are arranged on the inner walls of the conduits of the second cooling circuit, which are spaced apart from each other in its extension direction, each of which is connected with a voltage supply device for generating an alternating high voltage between at least two of the electrodes.

Abstract: A cooling device for cooling an inner part of an approximately sealed box includes a casing and a heat exchanger disposed in the casing. Plural inside air passages through which air inside the box flows and plural outside air passages through which air outside the box flows are alternately adjacently arranged in the heat exchanger. In the cooling device, both outside air introduction port and outside air discharge port are provided in an outer side plate of the casing, and a drain space is provided between the heat exchanger and the outer side plate of the casing so that outside air passages communicate with the outside air discharge port through the drain space. Thus, even when rain water is introduced into the casing from the outside air discharge port, almost rain water flows downwardly through the drain space, and it can restrict rain water from being introduced into the heat exchanger.

Abstract: The refractory shield assembly comprises: a semi-circular, elongate, metal shield; a plurality of spaced apart anchors protruding from the front surface of the shield; a layer of abrasion-resistant refractory material overlying the surface and extending between and engaging the anchors, whereby the refractory material is held on the shield by the anchors; and means, such as clamps, for securing the shield on a boiler tube. The refractory shield assembly functions to protect the underlying boiler tube from erosion by a stream of hot combustion gas containing particulates.

Abstract: A tubesheet support arrangement 11 supports a tubesheet 10 within a vessel 12, the tubesheet 10 maintaining a plurality of tubes 22 at fixed radial spacings from one another with the tubes 22 extending from the tubesheet 10 on a tube projecting side of the radial plane RP. The tubesheet support arrangement 11 comprises a fully circumferentially extending intermediary support element 24. The intermediary support element 24 is subjected to compression due its support of the weight of the tubesheet 10 and the tubes 22 on the lower portion of the vessel 12.

Abstract: To provide a thermal connection that can withstand mechanical stress in a high temperature structure comprising a panel having one face carrying a circuit made up of tubes in which a fluid flows, the outside walls of the tubes are covered in respective high thermal conductivity textile layers. The structure further comprises holding means for holding the tubes pressed in non-rigid manner against the panel. The structure enables heat exchange to take place between the panel and the fluid in order to cool the panel, to heat the fluid, or indeed in order to do both.

Abstract: In an adsorber for an adsorption type refrigerator of the present invention, aluminum heat exchangers 120, 130 arranged in a casing 110 are provided with films which do not permit moisture to pass therethrough, such as SiO3 films, anodic oxide coating films and several ppm to a hundred and several tens of ppm of inorganic negative ions such as PO43?, SiO32? are added in the water enclosed in the casing.

Abstract: A heat exchanger for transferring energy from a second fluid to a first fluid has a plurality of tubes to carry one of the fluids and a layer of thermal buffer members on one side of the tubes to act as a buffer to reduce high thermal stresses that may be caused by global temperature patterns and localized high gradients that occur in system transients such as start up and shutdown. Conventional heat exchangers often have a short lifespan due to high thermal stresses acting on the core of the heat exchanger. The heat exchanger uses the thermal buffer members as an increased thermal mass to cause the temperature of the heat exchanger core to change in a more gradual manner, thereby reducing thermal stresses.

Abstract: A heat transfer apparatus includes one heat exchanging system having a compressor coupled between a condenser and a heat exchanger. A further heat exchanging system includes a water pump, an ion exchange filter coupled between the water pump and the heat exchanger, to filter negative ions, positive ions, mineral materials, and/or impurities from the water. A temperature detecting member may actuate a heater to maintain the water temperature. A water cycling system includes a water reservoir to maintain the water pressure in the further heat exchanging system. An air relief valve may relieve air bubbles to reduce shocks and vibrations in the heat exchanging system.

Abstract: Disclosed are means for improving the service-life of indirect tubesheet type heat exchangers used in chemical reactors, particularly those exposed to reducing, nitridizing and/or carburizing environments. Such means include the use of certain ferrules within the heat exchange tubes and/or weld types used in construction of these heat exchangers.

Abstract: Thermal indictors of this invention are constructed for use with a heat exchanger generally comprising hot and cold side passages for accommodating a desired heat transfer therebetween. The thermal indicator is disposed at least partially within the heat exchanger and is formed from a material designed to undergo a permanent physical change when exposed to a temperature that is above a heat exchanger design operating temperature.

Abstract: A heat exchanger includes an aluminum member coated with a resin. The resin-coated aluminum member may be formed as a constituent part, e.g., a heat transfer member, a heater core, or the like, of the heat exchanger. In such heat exchangers, the aluminum member is connected to other resin-coated aluminum members by fusing the resin. Energy consumed during the connection of the aluminum members of the heat exchanger may be effectively reduced, and the manufacturing cost of the heat exchanger may be reduced, compared with that of heat exchangers made according to known methods that use a brazing filler metal.

Abstract: The heat transfer surfaces of a condensation heat exchanger are provided with a coating according to the invention which comprises a sequence of layers which includes at least one hard layer which comprises amorphous carbon or a plasma polymer and at least one soft layer which comprises amorphous carbon or a plasma polymer. The hard and soft layers are applied alternately, the first layer on the heat transfer surface being a hard layer and the last layer of the coating being a soft layer. The last, soft layer is distinguished in particular by hydrophobic properties. The layer sequence ensures condensation of drops and, at the same time, protects against drop impingement erosion.

Abstract: A hot air sealing arrangement for sealing between an inner surface of an exhaust duct conveying hot combustion products and an outer surface of a heat exchanger disposed within the exhaust duct includes an inner receiver attachable to the outer surface of the heat exchanger, an outer receiver attachable to the inner surface of the exhaust duct, and a seal having an outer bead engageable with the outer receiver for rotary movement therein and an inner bead engageable with the inner receiver for sliding movement therein. The seal further includes a connecting sheet between the outer bead and the inner bead.

Abstract: On the surface of a heat exchanging portion in a heat exchanger, a film made of a polyaniline is formed. When the heat exchanger operates, condensed water is adhered on the surface of the heat exchanger, and contacts the film made of the polyaniline. Accordingly, oxygen dissolved in the condensed water becomes active oxygen by the polyaniline, and organic substances contained in the condensed water is decomposed. Thus, an amount of organic substances attached to a surface of the heat exchanger can be reduced in low cost without equipment extension.

Abstract: A shell and coil type heat exchanger evaporator provides cooling for industrial coolants characterized by high viscosity and a poor heat transfer coefficient. A large heat transfer surface area is provided within a limited volume, and without a high coolant pressure drop. A short initial cool down period is provided due to minimized heat exchanger mass and minimized volume of liquid coolant in the heat exchanger during initial cool down.

Abstract: A boiler system includes combustion air conduit for directing the flow of combustion air through a first air heater (e.g., A-side heater) to a boiler and flue gas conduit for directing the flow of flue gas generated by the boiler to a second air heater (e.g., B-side heater). The combustion air conduit is configured to direct the majority of the combustion air to the first air heater, and the flue gas conduit is configured to direct the majority of the flue gas from the boiler to the second air heater.

Abstract: Use of an aqueous composition, which has been prepared by dissolving (A) dihydroxypropylchitosan and (B) 1,2,3,4-butanetetracarboxylic acid (B) in an aqueous medium, makes it possible to provide articles excellent in hydrophilicity, antibacterial and deodorant activities, touch feeling, antifogging property, paper strength, dyeability, waterproofness, antifouling property and/or the like.

Abstract: A flow distributor for mounting in an inlet of a heat exchanger includes a nose cone and one or more diverting rings. The nose cone is aerodynamically shaped to divert impingent gas flow around the nose cone. A first diverting ring is spaced outwardly from the nose cone and can be oriented such that at least a portion of the gas flow diverted by the nose cone is redirected into the wake of the nose cone. A second diverting ring can be spaced outwardly from the first diverting ring and can be oriented to divert gas flow impingent thereon. Struts connect the nose cone and one or more rings. Refractory on the wall of the inlet is shaped to reduce the recirculation at the outer perimeter thereof. The flow distributor is installed in the inlet with refractory to achieve substantially equal flow across the tube sheet of the heat exchanger.

Abstract: A heat exchanger which is adapted to an existing water tank to allow it to be heated or cooled using a hot or cold toxic or non-toxic liquid. Solar collectors and heat pumps can provide hot or cold liquids. To transfer this heat cheaply and economically to an existing hot or cold, water tank requires a simple efficient heat exchange, which can be easily adapted to the existing tank. The invention recited fills this need by simply screwing into the existing hot or cold, water tank and allow heat or cold to be added or extracted via a simple fluid loop, which is single wall isolated for non-toxic heat exchange fluids and double wall isolated for toxic heat exchange fluids.

Abstract: A process to reduce the temperature of a hydrogen and carbon monoxide containing gas by contacting the gas with a metal alloy surface having a lower temperature than the temperature of the gas, wherein the metal alloy surface has between 0 and 20 wt % iron, between 0 and 5 wt % aluminium, between 0 and 5 wt % silicon, between 20 and 50 wt % chromium and at least 35 wt % nickel, wherein the metal alloy surface maintains it lower temperature than the temperature of the gas by making use of coolant water.

Abstract: A corrosion-resistant alloy metal tube sheet used to construct a shell and tube heat exchanger (50) for cooling fluids with sea water passing through corrosion-resistant alloy tubes (25) contained in a horizontal carbon steel outer shell (1) that are supported and sealed at each end by passing them through holes (27, 30) in a carbon steel tube sheet (28, 31) and axially aligned holes (36, 37) in alloy tube sheets (34, 35) that cover and protect the adjacent interior carbon steel tube sheets from sea water corrosion. The walls of the holes (27, 30, 36, 37) have at least one annular groove (45, 46) and the ends of each tube are radially expanded to form circumferential ridges (40, 41) on the outside of each tube at a mating location with each of said annular grooves (45, 46) where they are forcibly driven into the grooves to form a circumferential joint having good mechanical strength and water tightness, thereby eliminating the need for welding the external joint between the alloy tube sheets and alloy tubes.

Abstract: A composition for reducing atmospheric oxidizing pollutants comprising a reducing agent comprising: at least one transition element and/or one or more compounds including at least one transition element wherein the standard electrode potential of the redox reaction including the transition element and an ionic species of the transition element or between the ionic species of the transition element present in the or each compound and a further ionic species of the transition element is less than +1.0 volt; a precious metal-free trap material capable of trapping at least one atmospheric reducing pollutant, whereby the at least one atmospheric oxidizing pollutant is reduced by a combination of the trap material and at least one trapped atmospheric reducing pollutant, which at least one trapped atmospheric reducing pollutant is consequently oxidized; or a manganese-based catalyst, preferably MnO2 or a derivative thereof including cryptomelane, and a water soluble binder.

Abstract: A plate heat exchanger, comprising a plurality of mutually facing plates that are hermetically coupled at at least one substantially peripheral portion and form at least two separate circuits for at least two fluids, each one of said plurality of plates having access ports that provide input ducts and output ducts for said at least two fluids, at least one portion of at least one face of at least one of said plurality of plates being uneven.

Abstract: An evaporator has at least one core. The core has tubes and a pair of tanks. The tube is configured to internally pass coolant, each of the tubes formed by bending a plate material and joining both edges of the bent plate material to each other. The pair of header tanks is connected to and communicating with each open end of the tubes. In the most windward core, the jointed edge of the tubes is arranged on the windward side.

Abstract: An apparatus and a method for inhibiting metal dusting corrosion of a tubesheet inside a shell-and-tube heat exchanger having at least one exit nozzle for transmitting at least one process fluid from the shell-and-tube heat exchanger include and use: an isolation baffle disposed inside the shell-and-tube heat exchanger at a location between a first exit nozzle and the tubesheet, whereby an isolated space exists between the tubesheet and the isolation baffle; and a means for purging the isolated space with a purging fluid.

Abstract: A cooling device for cooling an inner part of an approximately sealed box includes a casing and a heat exchanger disposed in the casing. Plural inside air passages through which air inside the box flows and plural outside air passages through which air outside the box flows are alternately adjacently arranged in the heat exchanger. In the cooling device, both outside air introduction port and outside air discharge port are provided in an outer side plate of the casing, and a drain space is provided between the heat exchanger and the outer side plate of the casing so that outside air passages communicate with the outside air discharge port through the drain space. Thus, even when rain water is introduced into the casing from the outside air discharge port, almost rain water flows downwardly through the drain space, and it can restrict rain water from being introduced into the heat exchanger.

Abstract: A Thermal Energy Heat Exchanger, is an air conditioning system, for the exterior unit of a fully assembled and installed heat pump and, or, air conditioning system, by means of a water refrigerant, from a source of water, such as, but not limited to a river, a lake, a pond, a swimming pool, a well, a creek, or an ocean; wherein a flow of water is circulated from the source of water by means of a water pumping device, 25A, under a controlled water pressure 25B, through an intake system of piping 25C, to a plurality of evaporator coils, positioned so as to surround the exterior unit by means of attachment to the inner chamber section of a protective cover enclosure, and through the plurality of evaporator coils, to an Outlet water disposal piping system, 25D; being in effect a heat pump and, or, air conditioner for the exterior unit of a fully assembled and installed heat pump and, or, air conditioning system, by means of a water refrigerant.

Abstract: The present invention provides a radiator that comprises: a radiator core for irradiating heat from coolant into the atmosphere; a top tank and a bottom tank respectively disposed at an upper portion and a lower portion of the radiator core; and a cover member mounting to the top tank and extending from an upper portion of the top tank to a lower portion of the top tank such that it covers the top tank.

Abstract: A wax decoration item is made by the method including the steps of mixing preparing polyethylene wax, cyanide polymer and white wax to be a mixture by way of heating; pouring the mixture in a mold and obtaining a wax item with fixed shape when removing the mold; melting a colloid material to be a transparent liquid and coating the colloid material onto an outer periphery surface of the wax item and the colloid material being not mixed with the wax item; condensing the colloid material which is fixed on the wax item.

Abstract: A condensing heat exchanger structure in contact with a combustion environment and which structure includes a ferrous substrate is provided with a corrosion resistant diffusion coating applied to the ferrous substrate via a fluidized bed application. Also provided is a method for improving the corrosion resistance of a condensing heat exchanger structure which includes a ferrous substrate and a surface portion at least partially exposed to a combustion product-containing environment. In such method, a corrosion resistant diffusion coating is applied onto the ferrous substrate via a fluidized bed application.