The Air Preheater Company, Inc.

Abb Air Preheater Inc.

William F Harder

Robin B Rhodes

Hermann E Kurschner

An air preheater has heat transfer elements with a first series of corrugated elements having longitudinally oriented, mutually parallel corrugations formed generally continuously across the lateral direction. Positioned on either side of each of the corrugated elements of the first series are a series of notched plates each having mutually parallel spaced apart notches. Each notch is formed by parallel double ridges projecting transversely from opposite sides and the element has flat sections between the notches. The notches are oriented obliquely in mutually opposite directions relative to the corrugations of the adjacent elements whereby the notched elements are in contact with the corrugated elements solely at the points of intersection of the notches and corrugations. This produces an increased number of boundary layer breaks and improves heat transfer as well as providing straight line passages through the elements.

Air preheater heat transfer surface

An improved element basket for a rotary air preheater includes at least one imperforate steel sheet, tack welded to the basket exterior, completely covering one side of the basket. A distal edge portion of the sheet is bent back upon itself and is biasable against a wall surface of the air preheater rotor. The side sealing member fills the gaps between the element basket and the adjacent rotor compartment wall, preventing gas or cold air from bypassing the heat transfer elements in the basket.

Rotary regenerative air preheater basket sealing

A heat transfer element assembly (30) is comprised of a plurality of first and second profiled heat transfer plates (32,34) which incorporate a series of first and second single-lobed outwardly protruding notches (40,50) which extend obliquely relative to the general direction of fluid flow through the assembled plates. The first and second profiled heat transfer plates (32,34) are assembled alternately in juxtaposed relationship in a stacked array with the obliquely extending spacing notches (40,50) of neighboring plates crossing each other. The first and second profiled head transfer plates are provided with a plurality of first single-lobed notches (40) protruding outwardly from one side of the plate and a plurality of second single-lobed notches (50) protruding outwardly from the other side of the plate. The first and second single-lobed notches are arranged in staggered relationship with one or more second single-lobed notches (50) disposed between each pair of first single-lobed notches (40).

Heat transfer element assembly

A rotary regenerative heat exchanger (2) for transferring heat from a hot fluid to a cold fluid by means of an assembly (30) of heat transfer element which is alternately contacted with the hot and cold fluid. The heat transfer element assembly (30) is comprised of a plurality of first and second heat absorbent plates (32,34) stacked alternately in spaced relationship. The spacing between adjacent first and second plates (32,34) are maintained apart by spacers which comprise bilobed folds (38A and 38B) crimped in the first plates (32) and second plates (34), respectively. The pitch of the folds (38B) is opposite to that of the folds (38A) to prevent nesting between adjacent plates.

Growing community of inventors

Wellsville, NY, United States of America

William F Harder