Abstract: Disclosed is a heat transfer assembly for a rotary regenerative preheater. The heat transfer assembly includes a plurality of heat transfer elements stacked in spaced relationship to each other in a manner such that each notch from a plurality of notches of one of the heat transfer element rests on respective flat sections from a plurality of flat sections of the adjacent heat transfer elements to configure a plurality of closed channels, each isolated from the other, wherein each of the channels has a configuration in a manner such that each of corrugation sections from a plurality of corrugation sections of one of the heat transfer elements faces respective undulation sections from a plurality of undulation sections of the adjacent heat transfer elements.

Abstract: A stack of heat transfer sheets includes one or more first sheet which includes a first undulating surface formed by first lobes that are parallel to each other and oriented at a first angle. The first sheets include a second undulating surface formed by second lobes that are parallel to each other and oriented at a second angle, different from the first angle. The first sheets include a third undulating surface formed by third lobes extending from one or more ends of the first sheet and terminating at an intermediate point between the end and an opposing end thereof. The third lobes are parallel to each other and parallel to the direction of flow through the stack. The stack includes one or more second sheets defining a plurality of sheet spacing features which engage a portion of the first sheet.

Abstract: Disclosed is a heat transfer assembly for a rotary regenerative preheater. The heat transfer assembly includes a plurality of heat transfer elements stacked in spaced relationship to each other in a manner such that each notch from a plurality of notches of one of the heat transfer element rests on respective flat sections from a plurality of flat sections of the adjacent heat transfer elements to configure a plurality of closed channels, each isolated from the other, wherein each of the channels has a configuration in a manner such that each of corrugation sections from a plurality of corrugation sections of one of the heat transfer elements faces respective undulation sections from a plurality of undulation sections of the adjacent heat transfer elements.

Abstract: A stack of heat transfer sheets includes one or more first sheet which includes a first undulating surface formed by first lobes that are parallel to each other and oriented at a first angle. The first sheets include a second undulating surface formed by second lobes that are parallel to each other and oriented at a second angle, different from the first angle. The first sheets include a third undulating surface formed by third lobes extending from one or more ends of the first sheet and terminating at an intermediate point between the end and an opposing end thereof. The third lobes are parallel to each other and parallel to the direction of flow through the stack. The stack includes one or more second sheets defining a plurality of sheet spacing features which engage a portion of the first sheet.

Abstract: A stack of heat transfer sheets includes one or more first sheet which includes a first undulating surface formed by first lobes that are parallel to each other and oriented at a first angle. The first sheets include a second undulating surface formed by second lobes that are parallel to each other and oriented at a second angle, different from the first angle. The first sheets include a third undulating surface formed by third lobes extending from one or more ends of the first sheet and terminating at an intermediate point between the end and an opposing end thereof. The third lobes are parallel to each other and parallel to the direction of flow through the stack. The stack includes one or more second sheets defining a plurality of sheet spacing features which engage a portion of the first sheet.

Abstract: A thermally efficiency regenerative air preheater 250 extracts more thermal energy from the flue gas exiting a solid fuel fired furnace 26 by employing an alkaline injection system 276. This mitigates acid fouling by selectively injecting different sized alkaline particles 275 into the air preheater 250. Small particles provide nucleation sites for condensation and neutralization of acid vapors. Large particles are injected to contact and selectively adhere to the heat exchange elements 542 and neutralize liquid acid that condenses there. When the deposit accumulation exceeds a threshold, the apparatus generates and utilizes a higher relative percentage of large particles. Similarly, a larger relative percentage of small particles are used in other cases. Mitigation of the fouling conditions permits the redesign of the air preheater 250 to achieve the transfer of more heat from the flue resulting in a lower flue gas outlet temperature without excessive fouling.

Abstract: A heat transfer sheet [60,160,260,360] for a rotary regenerative heat exchanger is shaped to include sheet spacing features [59], which provide spacing between adjacent heat transfer sheets [60,160,260,360], and undulation surfaces [68,70] (corrugations) in the sections between the sheet spacing features [59]. The undulation sections [68,70] are constructed of regularly spaced lobes [64,72] extending at an angle with respect to the spacing features [59]. The undulating sections [68,70] impart turbulence in the air or flue gas flowing between the heat transfer sheets [60, 160, 260, 360] to improve heat transfer. The heat transfer sheets [60,160,260,360] may include undulating surfaces that differ in angle of their lobes [64,72].

Abstract: A stack of heat transfer sheets includes one or more first sheet which includes a first undulating surface formed by first lobes that are parallel to each other and oriented at a first angle. The first sheets include a second undulating surface formed by second lobes that are parallel to each other and oriented at a second angle, different from the first angle. The first sheets include a third undulating surface formed by third lobes extending from one or more ends of the first sheet and terminating at an intermediate point between the end and an opposing end thereof. The third lobes are parallel to each other and parallel to the direction of flow through the stack. The stack includes one or more second sheets defining a plurality of sheet spacing features which engage a portion of the first sheet.

Abstract: A rotary air preheater 10 includes a housing 12 having a rotor 14. The rotor 14 has opposing ends 20,24 and is divided into sections by diaphragms 48. Sector plates 28 include one sector plate 28 in sealing relation with one of opposing ends 20,24 of the rotor 14. The air preheater 10 includes a flange 56 and a sensing device 49 coupled to at least one of the sector plates 28. The sensing device 49 provides non-contact sensing of a distance between the sector plate 28 and the flange 56. The sensing device 49 includes a conduit 54 that directs a jet of compressed air onto the flange 56, a first pressure sensor 60 and a second pressure sensor 70. The first pressure sensor 60 senses pressure inside the sensing device 49, and the second pressure sensor 70 senses pressure outside the sensing device 49. The distance between the sector plate and the flange is a pressure difference measured by the first and the second pressure sensors 60,70.

Abstract: A thermally efficiency regenerative air preheater 250 extracts more thermal energy from the flue gas exiting a solid fuel fired furnace 26 by employing an alkaline injection system 276. This mitigates acid fouling by selectively injecting different sized alkaline particles 275 into the air preheater 250. Small particles provide nucleation sites for condensation and neutralization of acid vapors. Large particles are injected to contact and selectively adhere to the heat exchange elements 542 and neutralize liquid acid that condenses there. When the deposit accumulation exceeds a threshold, the apparatus generates and utilizes a higher relative percentage of large particles. Similarly, a larger relative percentage of small particles are used in other cases. Mitigation of the fouling conditions permits the redesign of the air preheater 250 to achieve the transfer of more heat from the flue resulting in a lower flue gas outlet temperature without excessive fouling.

Abstract: A rotary air preheater 10 includes a housing 12 having a rotor 14. The rotor 14 has opposing ends 20,24 and is divided into sections by diaphragms 48. Sector plates 28 include one sector plate 28 in sealing relation with one of opposing ends 20,24 of the rotor 14. The air preheater 10 includes a flange 56 and a sensing device 49 coupled to at least one of the sector plates 28. The sensing device 49 provides non-contact sensing of a distance between the sector plate 28 and the flange 56. The sensing device 49 includes a conduit 54 that directs a jet of compressed air onto the flange 56, a first pressure sensor 60 and a second pressure sensor 70. The first pressure sensor 60 senses pressure inside the sensing device 49, and the second pressure sensor 70 senses pressure outside the sensing device 49. The distance between the sector plate and the flange is a pressure difference measured by the first and the second pressure sensors 60,70.

Abstract: A heat transfer sheet [60,160,260,360] for a rotary regenerative heat exchanger is shaped to include sheet spacing features [59], which provide spacing between adjacent heat transfer sheets [60,160,260,360], and undulation surfaces [68,70] (corrugations) in the sections between the sheet spacing features [59]. The undulation sections [68,70] are constructed of regularly spaced lobes [64,72] extending at an angle with respect to the spacing features [59]. The undulating sections [68,70] impart turbulence in the air or flue gas flowing between the heat transfer sheets [60, 160, 260, 360] to improve heat transfer. The heat transfer sheets [60,160,260,360] may include undulating surfaces that differ in angle of their lobes [64,72].

Abstract: A reagent drying system for use with a steam generation system [25] is described having a combustion chamber that produces exhaust flue gasses [FG2]. A preheater [150] receives the exhaust flue gasses [FG1] and transfers heat to create a heated input air stream [A2] and a diverted air stream [A2?]. The heated input air stream [A2] is provided to the combustion chamber. The diverted air stream [A2?] is provided to a dryer [196] as incremental air stream [IA]. Dryer [196] dries bulk reagents for dry milling into powder. The powder is then used to process the exhaust flue gasses to remove pollutants. The incremental air stream [IA] may also include leakage gasses [360] from preheater [150].

Abstract: A sector plate bypass seal includes a seal bar which engages the outboard end portion of the hot end sector plate and the portion of the housing proximate to the sector plate to close the gap therebetween. At least one bar clip has an upper segment mounted to the hot end center section and a lower segment mounted to the seal bar to hold the seal bar in axial position. At least one seal clamp is mounted to the outboard end portion of the sector plate and slidingly engages the seal bar to hold the seal bar in close engagement with the sector plate and housing portion while allowing vertical relative movement between the seal bar and the sector plate.

Abstract: An axial seal plate for an air preheater having a single, unitary structure including a sealing portion disposed intermediate first and second end portions extending orthogonally from the sealing portion. The axial seal plate does not including any welds for joining the end portions to the sealing portion.

Abstract: A sector plate for an air preheater including a seal plate having a sealing surface and an oppositely disposed mounting surface. Multiple tabs mount a portion of a rigid support structure to the mounting surface of the seal plate. Multiple support members mount the support structure to the air preheater.

Abstract: A transition element for providing an interface between a duct having a substantially rectangular cross section and an air preheater having a substantially circular cross section. The transition element includes an inner sidewall, an outer sidewall, and first and second end walls, where the outer sidewall and the first and second end walls form first and second transition corners. Each of the transition corners comprises first and second flow deflectors, each having an outer terminal edge and first and second side edges extending laterally from the terminal edge to an inner point. The first side edge of the first flow deflector is mounted to the second side edge of the second flow deflector and the outer terminal edges of the first and second flow deflectors are mounted to the duct to connect the air preheater to the duct.

Abstract: An axial seal plate for an air preheater having a single, unitary structure including a sealing portion disposed intermediate first and second end portions extending orthogonally from the sealing portion. The axial seal plate does not including any welds for joining the end portions to the sealing portion.

Abstract: A sector plate for an air preheater including a seal plate having a sealing surface and an oppositely disposed mounting surface. Multiple tabs mount a portion of a rigid support structure to the mounting surface of the seal plate. Multiple support members mount the support structure to the air preheater.

Abstract: A transition element for providing an interface between a duct having a substantially rectangular cross section and an air preheater having a substantially circular cross section. The transition element includes an inner sidewall, an outer sidewall, and first and second end walls, where the outer sidewall and the first and second end walls form first and second transition corners. Each of the transition corners comprises first and second flow deflectors, each having an outer terminal edge and first and second side edges extending laterally from the terminal edge to an inner point. The first side edge of the first flow deflector is mounted to the second side edge of the second flow deflector and the outer terminal edges of the first and second flow deflectors are mounted to the duct to connect the air preheater to the duct.