Abstract: An air preheater (APH) temperature control system, including at least a first APH or combustion/secondary air bypass duct in metered communication with a combustion air inlet duct and a secondary air duct, adapted in use to bleed a portion of the combustion air as secondary air bypass from the air inlet duct upstream of the APH 100 for reintroduction downstream into the secondary air duct, and a flow control device for metering or controlling volumetric flow of the secondary air bypass and tempering primary air flow in use operative to maintain the flue gas outlet temperature at or above a desired minimum predetermined temperature for the incident flue gas volumetric flow exiting the APH alone or in conjunction with other tempering means maintaining mills outlet temperature within a safety range of T10MIN to T10MAX.

Abstract: A heat pipe air preheater includes a multiplicity of heat pipes arranged in a plurality of superposed planar rows inclined relative to the horizontal, the rows of heat pipes including a first group of rows inclined at a first inclination angle and a second group inclined at a second inclination angle. Means are provided for removing collections of soot or other particulate matter from the evaporator ends of the heat pipes, the rows of the first group being disposed on one side of these means while the rows of the second group are disposed on the other side, the rows of the two groups converging in the direction of the heat pipe condenser ends.

Abstract: A heat pipe is formed of two elongated tubular members each having an open end and a closed end and joined at their open ends in gas-tight relationship by means of an annular collar. The annular collar is adapted at one end to fit over the open end of one of the elongated tubular members and at its other end to fit over the open end of other of the elongated tubular members, with the ends of the annular collar being sealably secured, such as by welding, bonding, threading or otherwise, to their respective tubular members thereby providing a gas-tight enclosure within the interconnected tubular which constitutes the working chamber of the heat pipe. Advantageously, the two elongated tubular members may be formed of dissimilar materials. For example, one tubular member may be formed of a more expensive material having a relatively high corrosion resistance and the other tubular member may be formed of a less expensive material having a relatively low corrosion resistance.

Abstract: An element basket assembly (30) for a rotary regenerative heat exchanger (2) comprised of a plurality of heat transfer element plates (32) stacked in an array between first and second end plates (34,36) disposed at opposite ends of the stacked array of heat transfer element plates (32). Upper and lower side straps (40,42 and 50,52) run along opposite sides of the stacked array of heat transfer element plates, to interconnect the first and second plates (34,36) to form the frame of the element basket housing the heat transfer element plates. A stiffening member (60) is disposed intermediate the spaced end plates (34,36) to extend transversely across the element basket assembly at or near the mid-span thereof the interconnect the upper side straps (40,42) and to interconnect the lower side straps (50,52) thereby increasing the structural integrity of the basket assembly.