Alan Lynn Marshall

US Patent:

62271504, May 8, 2001

Filed:

Apr 3, 2000

Appl. No.:

9/542557

Inventors:

Harlan E. Finnemore - Pocatello ID
Danny K. Hall - Wellsville NY
Alan G. Marshall - Wellsville NY
Robert J. Rausa - Nashua NH
Kent E. Ritter - Wellsville NY

Assignee:

ABB Air Preheater, Inc. - Wellsville NY

International Classification:

F23L 1502

US Classification:

122 1A

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.