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 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: An air preheater 100 is described having an air damper assembly 162 that partially restricts an air inlet 130 and a flue gas damper assembly 152 that partially restricts flue gas inlet 124 during periods of reduced boiler load. Restricting the flue gas inlet 124 reduces the effective surface area of the preheater causing more heat to pass to the cold end of the air preheater 100, reducing acid condensation and fouling. Restricting the gas inlet 124, increases gas velocity, thereby eroding accumulations in the air preheater 100, also reducing fouling. Restricting the air inlet 130 reduces the effective heat transfer surface area of the air preheater, which raises the gas temperature in the cold end of the air preheater and thereby reduces acid condensation and fouling.

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 exchanger 500 for transferring heat between a first gas flow 28, such as flue gases, and a second gas flow 34, such as air or oxygen, includes a housing 514 having a first inlet plenum 520 for receiving the first gas flow 28, a first outlet plenum 522 for discharging the first gas flow 28, a second inlet plenum 526 for receiving the second gas flow 34, and a second outlet plenum 528 for discharging the second gas flow 34. The heat exchanger 500 further includes heat exchange elements 512 disposed within the housing 514. Radial seals 224, 226, 228, 230 are disposed between the housing 514 and the heating elements 512 that define a radial plenum 535, 536. Axial seals 220, 222 are further disposed between the housing 514 and the heating elements 512 to define an axial plenum 530. A third gas flow, such as recirculated flue gas, is provided in the radial plenum 535, 536 and the axial plenum 530 to reduce the leakage between the first gas flow 28 and the second gas flow 34.

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 fume incinerator (10) and a method of operating same for eliminating combustible fumes from an oxygen bearing process gas stream (1). A first portion (11) of the oxygen bearing process gas (1) is passed to a burner (30) and serves as the source of oxygen for combusting an auxiliary fuel (9) to establish a flame front (28) within the incinerator. The remainder (13) of the process gas stream (1) is passed through the flame front for incineration of any obnoxious fumes contained therein.