Abb Air Preheater Inc.

Alstom Technology Limited

The Air Preheater Company, Inc.

Abb Preheater, Inc.

William C Cox

Harlan E Finnemore

Mark E Brophy

Kevin James O'Boyle

Thomas Gary Mergler

Glenn D Mattison

Gary C Goetschius

Rex R Snider

Michael W Wonderling

Mark T Casagrande

John D Proctor

A rotary air preheaterincludes a housinghaving a rotor. The rotorhas opposing endsand is divided into sections by diaphragms. Sector platesinclude one sector platein sealing relation with one of opposing endsof the rotor. The air preheaterincludes a flangeand a sensing devicecoupled to at least one of the sector plates. The sensing deviceprovides non-contact sensing of a distance between the sector plateand the flange. The sensing deviceincludes a conduitthat directs a jet of compressed air onto the flange, a first pressure sensorand a second pressure sensor. The first pressure sensorsenses pressure inside the sensing device, and the second pressure sensorsenses pressure outside the sensing device. The distance between the sector plate and the flange is a pressure difference measured by the first and the second pressure sensors. In one embodiment, the first pressure sensorsenses a backpressure within the sensing device

System and method for non-contact sensing to minimize leakage between process streams in an air preheater

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.

Sector plate and seal arrangement for trisector air preheater

The rotor for a rotary regenerative air preheater is fabricated from a combination of shop assembled rotor sector modules and field assembled components so as to eliminate the double plate diaphragms of conventional modular rotors. The shop assembled modules comprise one or more sectors and the field assembled components fit between the spaced shop assembled modules spaced around the rotor hub. The support gratings between the diaphragm plates support modular heat exchange baskets which are loaded into the rotor radially from the periphery.

Air preheater with semi-modular rotor construction

A control system for regulating the temperature of a heat detector disposed on a heat exchanger. The control system includes a temperature detector (42) for determining the temperature of the hot spot sensor (32), non-liquid cooling means (50,52) for cooling the detector when its temperature is above the desired temperature range, and non-liquid heating means (48,53) for heating the detector when its temperature is below the temperatures range. The control system includes control means (82) coupling the temperature sensing means to the non-liquid heating and cooling means. By keeping the heat detector at a generally constant temperature, the accuracy of the hot spot sensor on the heat exchanger is improved.

Temperature control system for a heat detector on a heat exchanger

A detector (32) monitors infrared ray emissions from an air preheater (10) rotor (14) to detect a temperature rise that precedes a fire within air preheater (10) with each sensor output being processed independently by signal processing electronics. The instantaneous minus the average temperature of rotor (14) is calculated and compared to a variable trip level signal to determine whether a hot spot has been detected. The detector (32) scans across the face of rotor (14) until an initial hot spot is detected, whereupon the scanner motor (58) ceases operation thereby locating the scanner over the rotor radial position of the detected hot spot. If the same hot spot is detected on the next subsequent rotor pass, a hot spot alarm (60) is energized. If the hot spot is not detected on the next subsequent rotor pass, detector scanning is resumed by energizing scan motor (58).

Method of detecting hot spots in a rotary heat exchanger

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Wellsville, NY, United States of America

William C Cox