Circumferential & Bypass seals

The circumferential seals prevent air and gas from bypassing the heating surface through the space between the rotor and the housing shell. They are retained by mounting angles bolted to the circumference of the rotor. The circumferential seals wear against the sealing rings, which are welded to the housing of the air preheater. The bypass seals differ from circumferential seals by reducing the quantity of air flowing over the outer rim of the rotor, as the task of reducing axial leakage is handled by the axial sealing system. The bypass seals are mounted on the housing and seal against the rotor mounted T-bar. Circumferential and bypass seals are equipped in the hot and cold ends of air preheaters.

DuraFlex™ an efficient seal

The DuraFlex Technology is a patented and industry proven product line exclusively designed for customers seeking to maximize the efficiency and reliability of the air preheater. This product line has an unmatched track record in the industry; efficiency improvements have increased our customer productivity and significantly reduced fuel cost. The product quality is unsurpassed and customers report they last longer than any high-performance sealing product available in the market place. The DuraFlex high-performance circumferential and bypass seals use a patented revolutionary interlocking design. This technique reduces the air gaps normally found in other circumferential or bypass sealing systems.

Benefits

The DuraFlex design provides an edge free surface that prevents seal tabs from being torn loose, in the event the rotor comes in contact with the seal or a foreign object, such as a clinker becomes lodged between the rotor and the seal. With standard circumferential and bypass designs, it is very common for seal tabs to be torn away thus exposing large gaps which provide paths for leakage past the air preheater. The DuraFlex circ/bypass seals contain two layers in one interlocking seal, so that only one-half of the number of seals are required compared to standard seals, and the seals can be installed in one-half the time compared to standard seals. DuraFlex seals are designed to increase the efficiency of the plant by reducing station fan power usage, increasing the thermal efficiency of the air preheater, and reducing the overall net heat rate of the plant.

Features

• Superior sealing technology for improved fuel efficiency and fan performance • Corrosion resistant for increased durability and longevity in SCR environments • Built in thermal properties to ensure minimal distortion under high temperatures • Patented design ensures constant contact for maximum sealing and the reduction of air leakage • Precision manufacturing processes that incorporate stage stress testing • Holding strips and fasteners included for bypass seals • Fasteners included for circumferential seals • Easier and faster to install

Technical Description

DuraFlex is a bypass or circumferential seal for a rotary regenerative air preheater. The seal is comprised of two members 1 that each have a plurality of 2 tabs and 3 slots. The tabs and slots interlock so that the tabs on one member are positioned adjacent the slots on the other member. Further, the tabs have a narrow neck section and a wider sealing section. 4 The wider sealing sections overlay and the narrow neck sections are positioned within a recessed region of the notch on the opposite member so as to interlock the two members. The neck sections do not significantly overlap thereby providing greater flexibility for each of the tabs. The seal is mounted either to the rotor or to the inner wall of the housing so as to extend through the bypass gap between the rotor and the inner wall of the housing.

Unique Interlocking Design Provides Strength with Flexibility

The DuraFlex high-performance circumferential and bypass seal use a patented revolutionary interlocking design. This design reduces the air gaps normally found in other circumferential or bypass sealing systems.

DuraFlex Manufacturing Process

DuraFlex seals are manufactured utilizing a 5 stage process; each step is quality checked and measured to ensure the production of the seal is consistent and precise. The seals are labeled then stacked and coated with a corrosion resistant sealant, palletized and wrapped in plastic, to maintain the integrity through transportation and weather exposure after delivery.

Satisfied Customers . . . . A Paragon Tradition

Paragon Airheater Technologies is dedicated to total customer satisfaction. We use quality mill-certified raw materials and craftsmanship in every aspect of our manufacturing process. Our research staff and engineering group can custom design solutions for any specific application and our technical services group is available for consultation and installation assistance.

Performance Guarantee Contact your Paragon Representative for details on the Product Performance Guarantee

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