Abstract: A method and an arrangement for sensing the clearance between an object and an object-adjacent surface, which is particularly for use in difficult ambient conditions, such as in dirty, corrosive environments and under varying temperature and pressure conditions, e.g. to measure and hold constant the clearance between the sector plates (3, 4) of a regenerative rotary air preheater and the end surfaces of the rotor (2, 8). The sensing device (7) includes a compressed-air operated pipe (9) which is mounted on the object (3, 4) and which includes a sound-emitting opening (14) located adjacent the surface (8), wherein changes in the distance (S) between the object (3, 4) and the surface (8) are represented by changes that occur in the resonant frequency of the pipe (9).

Abstract: The rotor of an existing rotary regenerative air preheater is retrofitted with deeper cold end baskets for general performance enhancement and/or for the tolerance of ammonium bisulfate deposits. the normal cold end support gratings are removed and the support of the cold end baskets of increased depth is at least partially from the existing rotor stay plates.

Abstract: Drive means are provided to move the sector plates of rotary regenerative air preheaters into sealing position with the radial seals on the rotor during rotor turndown. A pair of fluid drive cylinders are connected to a pair of drive chains which rotate a drive shaft. One of the pair of drive cylinders may operate in the extend mode while the other operates in the retract mode or both cylinders may operate in the same mode at the same time for increased force in one direction. Eccentric disk devices are attached to the drive shaft and to the sector plates for converting the rotary motion of the shaft to linear motion of the attachment to the sector plates. The eccentric disk devices may contain two eccentric disks so that the distance of travel can be adjusted.

Abstract: A rotary air preheater has a rotor, at least one seal disposed proximate to the rotor, a drive for reciprocally driving a portion of the seal between a first position adjacent the rotor and a second position spaced from the first position, and a control system for activating the drive. The control system includes a boiler load power sensor, means for storing a first stored boiler load having a value between the minimum boiler load and the maximum boiler load, and logic for comparing the sensed boiler load to the first stored boiler load. The logic provides a first activation signal to the drive when the sensed boiler load rises above the first stored boiler load and a second activation signal to the drive when the sensed boiler load falls below the first stored boiler load. The first activation signal activates the drive to drive the portion of the seal to the first position and the second activation signal activates the drive to drive the portion of the seal to the second position.

Abstract: A heat transfer assembly for a rotary regenerative air preheater has heat transfer plates which include means for spacing the plates apart to form flow passages and a plurality of rows of V-shaped ribs extending across the flow passages. Alternate rows of V-shaped ribs on each plate protrude outwardly from opposite surfaces of the plate. Several arrangements for aligning the ribs on one plate with the ribs on the adjacent plate are described as are alternate orientations of the adjacent rows of ribs on each plate. The relationship of the height of the ribs to the plate spacing is defined as is the relationship of the rib spacing to the rib height and the plate spacing to the length of the V-shaped rib sections.

Abstract: A multiple rake sootblower reciprocates over an area to clean an entire surface using a minimum of space for the sootblower stroke. An internal valving manifold and a plurality of bushings inside of a plenum isolate the rakes from each other and operate one rake at a time. This maintains the required sootblowing media pressure at the nozzles of each of the rakes. The internal valving manifold may either be reciprocated or rotated to select the desired rake.

Abstract: A sector plate static sealing arrangement for a rotary regenerative air preheater employs a single rib attached to and extending along the center line of the sector plate toward the air preheater casing. The rib cooperates with a static seal attached to the casing to provide both the sealing and positioning functions. Braces for the rib provide support and form a sloped surface which reduces ash accumulation.

Abstract: A regenerative, rotary heat exchanger includes a stationary housing; a rotatable rotor in the housing; radially extending partition walls in the rotor separating the rotor into sectors; and a regeneratable mass in the sectors. Axially adjustable sector plates are located in sealing relation with respect to respective axial end surfaces of the rotor into which and out from which two heat exchanging media are directed in counter-flow separated by the partition walls. A flange is fixedly attached to the rotor and extends circumferentially around at least one of the respective axial end surfaces of the rotor, and a sensing device senses a clearance between at least one of the sector plates and the flange. A controller adjusts the clearance to a predetermined size responsive to the sensing device.

Abstract: The support grating system for the heat exchange baskets of a rotary regenerative air preheater is arranged to be able to make full use of the rotor volume for the heat absorbent material. Support gratings can be located inside of the volume of the rotor enclosed by the pin rack assembly and baskets can still be loaded. This is accomplished by installing certain of the support gratings or portions thereof after the baskets have been loaded into position in the basket layer inside of the pin rack assembly.

Abstract: A swing-arm sootblower for a rotary regenerative air preheater is mounted to sweep across the air preheater rotor at an adjustable constant speed or angular velocity. The sootblower has means for sootblowing with a relatively low pressure medium such as air or steam or with high pressure water. The nozzle unit is equipped with a low pressure nozzle and a plurality of high pressure nozzles. The high pressure nozzles are arranged in a row and the nozzle unit is mounted so that the row is at an angle to the swing arm such that the row of high pressure nozzles is parallel to the heat transfer plates and tangential to the rotor at the outside of the swing of the arm.

Abstract: A rotary, regenerative heat exchanger includes an inner cylindrical hub (2) provided in a vertical position, a rotor (1) containing a heat exchange medium, first attachment members (30) for attaching the rotor to the hub, and a stationary casing (6) surrounding the rotor. A bearing (3) is provided to journal a lower end of the hub, and a slow moving hydraulic motor (4) is adapted to slowly turn the hub. The motor is provided with a housing enclosing a built-in radial bearing (26) and coaxially therewith a cylinder block and cam surface arrangement having a circular cylinder block (24) and a cam surface (21) surrounding the cylinder block and cooperating with a piston mechanism (22, 23) of the cylinder block such that reciprocation of the piston mechanism causes relative motion between the cylinder block and the cam surface. Second attachment members (5, 8, and 10) are provided to attach the motor to the stationary casing and to the hub, respectively.

Abstract: The thermal performance of the heat transfer element assemblies for rotary regenerative air preheaters is optimized to provide a desired level of heat transfer and pressure drop with a reduced volume and weight. The heat transfer plates in the assemblies have notches for maintaining plate spacing and oblique undulations between the notches. The undulations on adjacent plates extend at opposite oblique angles. The ratio of the openings of the undulations to the openings of the notches is greater than 0.3 and less than 0.5. The pitch (spacing) of the notches is greater than two inches and the angle of the undulations with respect to the notches is greater than 20.degree. and less than 40.degree..

Abstract: Heat transfer elements for rotary regenerative heat exchangers are formed with spacing ridges or notches having flow-disrupting indentations in the peaks of the notches formed at selected intervals to project into the flow channels. These projections interrupt the boundary layer and cause turbulence and mixing to enhance the heat transfer. Various methods of forming the indentations are disclosed.

Abstract: Heat transfer elements for rotary regenerative heat exchangers are formed with spacing ridges or notches having flow-disrupting indentations in the peaks of the notches formed at selected intervals to project into the flow channels. These projections interrupt the boundary layer and cause turbulence and mixing to enhance the heat transfer. Various methods of forming the indentations are disclosed.

Abstract: A trisector air preheater includes sector plates between the primary air sector and the flue gas sector and between the secondary air sector and the flue gas sector which are of a large size so as to provide double radial seals. However, the sector plate between the primary and secondary air sectors is small and provides only a single radial seal. The one smaller sector plate reduces the pressure drop through the air preheater while sacrificing increased leakage only between air sectors. The axial seal between the primary and secondary air sectors may be maintained at a double seal size.

Abstract: A sealing arrangement for a quad sector rotary regenerative air preheater has a rotor rotatably mounted in a housing. The rotor has radially extending diaphragms forming compartments and radial seals extending along the edges of the diaphragms. Sector plates are positioned at the axial ends of the rotor to divide the preheater into a flue gas sector, a primary air sector and a first secondary air sector adjacent said flue gas sector and said primary air sector, and a second secondary air sector positioned adjacent said flue gas sector and said primary air sector. The sector plates between the flue gas sector and said secondary air sectors are in sealing engagement with two of the radial seals at all times and the sector plates between the primary air sector and the secondary air sectors are in sealing engagement with only one of the radial seals at any particular time.

Abstract: A heating element basket assembly for a rotary regenerative air preheater has a picture-frame structure with the open areas on each side being covered by a flat plate attached to the inside of the frame. A sealing plate member is attached to the outside of each of the flat plates within framework. The sealing plate member has a portion bend and protruding outwardly from the periphery of the basket to form a flexible seal for engagement with the diaphragms and stay plates of the rotor.

Abstract: The gas flow bypass around the heating elements in a regenerative air preheater is reduced by the use of floating bypass seals which are placed in the rotor compartments between stacked heating elements. The seals comprise a frame with an open center with the peripheral frame portion bridging the gaps between the heating elements and the sides of the compartments. The seals may be adjustable and may include a deformable edge seal to actually contact and seal against the sides.

Abstract: Adjoining heat exchange modules of a recuperative cross flow plate-type heat exchanger are joined into a single unit by means of common plate spacer bars. Each common spacer bar extends between and into the adjacent modules. The prior art mid-module gaps are eliminated.

Abstract: A heat exchange element for an air preheater has first and second heat transfer elements arranged to form channels for the passage of a heat exchange media having a main flow direction. Each of the heat exchange plates has parallel straight ridges and flats between the ridges. The ridges alternate to extend transversely from opposite sides of each heat transfer plate. The ridges of the adjacent plates are oriented obliquely in opposite directions relative to the main flow direction and contact each other solely at points of intersection of the ridges.