Flexible seal for a rotary regenerative preheater

Abstract

A seal assembly includes a leaf assembly and a supplemental leaf assembly. The leaf assembly includes a first leaf having a first base section. The first base section defines a first fastening area for securing the first leaf to a diaphragm of the preheater. The first leaf has a first elongate section extending away from the first base section and terminating at a first distal end thereof. The leaf assembly further includes a second leaf that engages a portion of the first leaf. The second leaf has a second base section. The second base section defines a second fastening area for securing the second leaf to the diaphragm. The second leaf has a second elongate section extending away from the second base section and terminating at a second distal end thereof. The supplemental leaf assembly is secured to the first leaf and slidingly engaging the second leaf.

What is claimed is: 
     
         1 . A seal assembly for a rotary preheater, the seal assembly comprising:
 a leaf assembly comprising:
 a first leaf having a first base section, the first base section defining a first fastening area for securing the first leaf to a diaphragm of the preheater, the first leaf having a first elongate section extending away from the first base section and terminating at a first distal end thereof; 
 a second leaf engaging a portion of the first leaf and having a second base section, the second base section defining a second fastening area for securing the second leaf to the diaphragm, the second leaf having a second elongate section extending away from the second base section and terminating at a second distal end thereof; and 
 a supplemental leaf assembly secured to the first leaf and slidingly engaging the second leaf. 
   
     
     
         2 . The seal assembly of  claim 1 , wherein the second distal end terminates between the first distal end and the first base section. 
     
     
         3 . The seal assembly of  claim 1 , wherein the supplemental leaf assembly comprises a spacer secured to the first leaf and a third leaf secured to the spacer, the third leaf slidingly engaging the second leaf. 
     
     
         4 . The seal assembly of  claim 1 , wherein:
 the second distal end terminates between the first distal end and the first base section;   the supplemental leaf assembly comprises a spacer secured to the first leaf and a third leaf secured to the spacer, the third leaf slidingly engaging the second leaf; and   wherein the spacer is positioned between the first leaf and the third leaf, the spacer being spaced apart from the second distal end thereby defining a gap between the spacer and the second distal end to accommodate movement of the spacer relative to the second distal end.   
     
     
         5 . The seal assembly of  claim 1 , further comprising at least one displacement member, the at least one displacement member having a first engagement portion configured to displace a first portion of the leaf assembly a first distance and the at least one displacement member having a second engagement portion configured to displace a second portion of the leaf assembly a second distance, wherein the first distance and the second distance are different. 
     
     
         6 . The seal assembly of  claim 5 , wherein each of the at least one displacement member has an L-shaped configuration defining a first leg and a second leg, the first leg defining a third base portion that is configured to be secured to the diaphragm and the second leg comprising one of the first engagement portion and the second engagement portion. 
     
     
         7 . The seal assembly of  claim 5 , wherein the at least one displacement member is arranged to establish a predefined contour of the leaf assembly. 
     
     
         8 . The seal assembly of  claim 7 , wherein the predetermined contour is configured to compensate for movement of the preheater during operation. 
     
     
         9 . The seal assembly of  claim 3 , wherein the spacer protrudes outwardly from at least one of the first leaf and the second leaf. 
     
     
         10 . The seal assembly of  claim 1 , further comprising a strip having fourth base section engaging the second base section, the second base section being positioned between the first base section and the fourth base section and the strip defining a deflector section extending away from the fourth base section and away from the second leaf. 
     
     
         11 . The seal assembly of  claim 1 , further comprising a bar aligned with a portion of the first base section and the second base section. 
     
     
         12 . The seal assembly of  claim 3 , wherein the spacer comprises at least one of a hardened material, a weld, a rivet, a leaf and a bend in one of the first leaf and the third leaf. 
     
     
         13 . A preheater assembly comprising:
 a rotor assembly rotatably mounted on a rotor post and disposed in a housing, the rotor assembly defining diaphragms extending radially from the rotor post to an outer periphery of the rotor assembly, adjacent pairs of the diaphragms defining respective compartments for receiving a heat transfer assembly, each of the heat transfer assemblies including a plurality of heat transfer sheets stacked upon one another, the housing including a flue gas inlet duct and a flue gas outlet duct for channeling the flow of heated flue gases through the preheater, the housing including an air inlet duct and an air outlet duct for channeling the flow of combustion air through the preheater, the preheater including an upper sector plate extending across the housing adjacent to an upper face of the rotor assembly and a lower sector plate extending across the housing adjacent to lower face of the rotor assembly, the upper sector plate extends between and is joined to the flue gas inlet duct and the air outlet duct, the lower sector plate extends between and is joined to the flue gas outlet duct and the air inlet duct, the upper and lower sector plates, respectively, are joined to one another by a circumferential plate;   at least one of the upper sector plate and the lower sector plate defining a leading edge and a trailing edge, and wherein at least one of the leading edge and the trailing edge defines a ramped configuration; and   a seal assembly positioned on an axial edge of each diaphragm, the seal assembly comprising:   a leaf assembly comprising:
 a first leaf having a first base section, the first base section defining a first fastening area for securing the first leaf to a diaphragm of the preheater, the first leaf having a first elongate section extending away from the first base section and terminating at a first distal end thereof; 
 a second leaf engaging a portion of the first leaf and having a second base section, the second base section defining a second fastening area for securing the second leaf to the diaphragm, the second leaf having a second elongate section extending away from the second base section and terminating at a second distal end thereof; and 
 a supplemental leaf assembly secured to the first leaf and slidingly engaging the second leaf; and 
 wherein a portion of the seal assembly engages the leading edge and disengages the trailing edge. 
   
     
     
         14 . The preheater of  claim 13 , wherein the second distal end terminates between the first distal end and the first base section. 
     
     
         15 . The preheater of  claim 13 , wherein the supplemental leaf assembly comprises a spacer secured to the first leaf and a third leaf secured to the spacer, the third leaf slidingly engaging the second leaf.