초록 ▼

Powder coated heat exchange elements for a heat exchanger. Powder coating provides improved protective coating on surfaces of heat exchange elements. In many applications, the heat exchange elements are subjected to harsh operating conditions that promote corrosion. Traditional enamel coating tends

Powder coated heat exchange elements for a heat exchanger. Powder coating provides improved protective coating on surfaces of heat exchange elements. In many applications, the heat exchange elements are subjected to harsh operating conditions that promote corrosion. Traditional enamel coating tends to fracture when subjected to mechanical stresses thereby allowing corrosion inducing agents to penetrate and corrode the underlying surfaces. Powder coating reduces breaches in the protective layer. Powder coating may be adapted to withstand high temperatures so as to make them suitable for use in harsh operating environments. One such environment can be found in the processing of flue gas from fossil burning power generators, where the flue gas has a relatively high temperature and high sulfur content.

대표청구항 ▼

What is claimed is: 1. A heat exchanger comprising: a heat exchanging body rotatable relative to a housing; and a plurality of heat exchange elements disposed in the heat exchanging body so as to define a plurality of channels that allow air to flow therethrough, wherein each heat exchange element

What is claimed is: 1. A heat exchanger comprising: a heat exchanging body rotatable relative to a housing; and a plurality of heat exchange elements disposed in the heat exchanging body so as to define a plurality of channels that allow air to flow therethrough, wherein each heat exchange element includes a resilient and mechanically durable powder coating with an operational temperature limit of approximately 975° F. and consisting of dry powder particles configured to cure at a temperature above ambient to provide a protective layer configured to inhibit corrosion inducing agents formed in a selective catalytic reduction process during operation of a fossil fuel burning power plant from contacting an underlying surface of the heat exchange element to thereby resist corrosion of the heat exchange element, wherein the thickness of the powder coating on the heat exchange elements is between 1.5-2.5 mils, said thickness configured to inhibit said corrosion inducing agents from contacting said underlying surface of the heat exchange elements to thereby resist corrosion of the heat exchange elements, while not inhibiting heat transfer between the heat exchange elements and said airflow. 2. The heat exchanger of claim 1, wherein the heat exchanging body comprises a rotor, wherein the rotor is adapted to rotate about a rotational axis with respect to the housing such that a given portion of the rotor gains heat energy at a first location and gives off heat energy at a second location. 3. The heat exchanger of claim 2, wherein the heat exchanger further comprises a first air passage assembly disposed adjacent the heat exchanging body, and wherein the air passage assembly is adapted to allow air to flow through a portion of the heat exchange body. 4. The heat exchanger of claim 3, wherein the first air passage assembly is disposed adjacent the rotor at one of the first or second locations. 5. The heat exchanger of claim 3, wherein the air passage assembly is adapted to allow flow of air through a portion of the heat exchange body along a first direction relative to the rotational axis. 6. The heat exchanger of claim 5, wherein the first direction is substantially parallel to the rotational axis. 7. The heat exchanger of claim 1, wherein the heat exchanging body is divided into a plurality of sectors, and wherein each sector includes at least one heat exchange element positioned therein. 8. The heat exchanger of claim 1, wherein the powder coating comprises a high silica content. 9. The heat exchanger of claim 1, wherein the powder coating is configured to withstand approximately 1000° F. for approximately 24 hours. 10. The heat exchanger of claim 1, wherein the heat exchanger is configured to reduce the temperature of a flue gas emitted from the fossil fuel burning power plant prior to the ejection of said flue gas into the environment. 11. A heat exchanger comprising: a heat exchanging body that rotates with respect to a housing; a first air passage assembly disposed adjacent the heat exchanging body, wherein the air passage assembly is adapted to allow flow of air through a portion of the heat exchange body; and a plurality of heat exchange elements disposed in the heat exchanging body, wherein each heat exchange element defines a heat exchanging surface adapted to facilitate the heat exchange with the air flowing through the heat exchanging body, and wherein the heat exchanging surface includes a resilient and mechanically durable powder coating with an operational temperature limit of approximately 975° F. and consisting of dry powder particles configured to cure at a temperature above ambient to provide a protective layer configured to inhibit corrosion inducing agents formed in a selective catalytic reduction process during operation of a fossil fuel burning power plant from contacting an underlying surface of the heat exchange element to resist corrosion thereof, wherein the thickness of the powder coating on the heat exchange elements is between 1.5-2.5 mils, said thickness configured to inhibit said corrosion inducing agents from contacting said underlying surface of the heat exchange elements to thereby resist corrosion of the heat exchange elements, while not inhibiting heat transfer between the heat exchange elements and said airflow. 12. The heat exchanger of claim 11, wherein the heat exchanging body comprises a rotor, wherein the rotor is adapted to rotate about a rotational axis with respect to the housing such that a given portion of the rotor gains heat energy at a first location and gives off heat energy at a second location. 13. The heat exchanger of claim 12, wherein the first air passage assembly is disposed adjacent the rotor at one of the first or second locations. 14. The heat exchanger of claim 12, wherein the air passage assembly is adapted to allow flow of air through a portion of the heat exchange body along a first direction relative to the rotational axis. 15. The heat exchanger of claim 14, wherein the first direction is substantially parallel to the rotational axis. 16. The heat exchanger of claim 11, wherein the heat exchanging body defines a plurality of segments, and wherein each segment defines a volume dimensioned to receive a plurality of heat exchange elements, and wherein each segment extends from a first angle to a second angle so as to generally resemble a pie-slice shape when viewed along the rotational axis. 17. The heat exchanger of claim 11, wherein the heat exchange elements comprise shaped sheets of material dimensioned so as to be stackable along a radial direction, and wherein the shaped sheets are oriented so as to allow flow of air with a net direction that is generally parallel to the rotational axis. 18. The heat exchanger of claim 17, wherein the shaped sheets comprise a material selected from the group consisting of a sheet of metal, a sheet of stainless steel, a sheet of low carbon steel. 19. The heat exchanger of claim 17, wherein the thickness of the shaped sheet is between approximately 18-24 gauge. 20. The heat exchanger of claim 17, wherein the shaped sheets define a plurality of channels for the flow of air such that, when stacked, the channels extend in a direction substantially parallel to the rotational axis. 21. The heat exchanger of claim 17, wherein the shaped sheets comprises a first type of sheet and a second type of sheet such that the first type of sheet defines a plurality of channels that extend along a first direction relative to the rotational axis and the second type of sheet defines a plurality of channels that extend along a second direction relative to the rotational axis. 22. The heat exchanger of claim 21, wherein the channels of the first type of sheet and the channels of the second type of sheet faun crossing patterns. 23. The heat exchanger of claim 11, wherein the heat exchanger is configured to reduce the temperature of a flue gas emitted from the fossil fuel burning power plant prior to the ejection of said flue gas into the environment. 24. A heat exchange assembly for a heat exchanger having a heat exchanging body that rotates in a first direction with respect to a housing, the assembly comprising: a plurality of heat exchange members that are formed so as define a heat exchange surface, wherein the heat exchange members are positioned in the heat exchanging body to thereby facilitate heat exchange with a flow of air; and a protective layer disposed on the heat exchange surface, wherein the protective layer comprises a resilient and mechanically durable powder coating with an operational temperature limit of approximately 975° F. and consisting of dry powder particles configured to cure at a temperature above ambient to provide the protective layer configured to inhibit corrosion inducing agents formed in a selective catalytic reduction process during operation of a fossil fuel burning power plant from contacting an underlying surface of the heat exchange members to inhibit corrosion of the heat exchange members, wherein the thickness of the powder coating on the heat exchange surface is between approximately 1.5-2.5 mils, said thickness configured to inhibit said corrosion inducing agents from contacting said underlying surface of the heat exchange members to thereby resist corrosion of the heat exchange members, while not inhibiting heat transfer between the heat exchange members and said airflow. 25. The assembly of claim 24, wherein the powder coating comprises a high silica content. 26. The assembly of claim 24, wherein the powder coating is configured to withstand approximately 1000° F. for approximately 24 hours. 27. The assembly of claim 24, wherein the heat exchange members comprise a low carbon steel. 28. The assembly of claim 24, wherein the thickness of the heat exchange members is between approximately 18-24 gauge. 29. The assembly of claim 24, wherein the heat exchange members are formed so as to define a plurality of channels to allow air to flow along the channels so as to facilitate heat exchange with the air. 30. The assembly of claim 24, wherein the heat exchange members comprise a cross sectional shape including a plurality or undulations separated by a flat section, and wherein each undulated shape comprises an upper curved shape joined to a lower curved shape so as to form a full cycle wave like structure. 31. The assembly of claim 24, wherein the heat exchange members comprises a corrugated configuration. 32. The assembly of claim 24, wherein the heat exchange members comprise a notched flat configuration. 33. The assembly of claim 24, wherein the powder coating provides a barrier for the underlying heat exchange members to thereby resist corrosion inducing agents including water and sulfur based compounds. 34. The assembly of claim 24, wherein the powder coating protective layer has a hardness value greater than a selected level and a high resilience in an acidic environment. 35. The assembly of claim 34, wherein the selected value level of hardness value is approximately 2H in a ASTM Method D3363 pencil hardness standard. 36. The heat exchanger of claim 1, wherein the corrosion inducing agents comprise sulfur based compounds. 37. The heat exchanger of claim 11, wherein the corrosion inducing agents comprise sulfur based compounds. 38. The assembly of claim 24, wherein the corrosion inducing agents comprise sulfur based compounds. 39. The heat exchanger of claim 1, wherein the powder coating is a polyester based powder coating. 40. The heat exchanger of claim 11, wherein the powder coating is a polyester based powder coating. 41. The heat exchanger of claim 24, wherein the powder coating is a polyester based powder coating.