Press Release

November 7, 2003

SECO/WARWICK is Awarded Patent for Adjustable Ratio Control System and Method

For Immediate Release

Meadville, PA USA

The United States Patent and Trademark Office has issued SECO/WARWICK Corporation patent no. US 6,609,906B1 on August 26, 2003 for the Adjustable Ratio Control System and Method used in the design of Aluminum Process Heat Treating Equipment.

About the Adjustable Ratio Control System

As an enhancement to the conventional ratio control system, SECO/WARWICK offers the adjustable ratio control system that provides improved temperature control and cycle reduction in multi-zone furnaces, not loaded perfectly. Please review the information outlined below


Conventional Ratio	Adjustable Ratio

Conventional Ratio

Zone Air SP = Work SP + Ratio (Work SP – Zone Work Temp)

Adjustable Ratio

Zone Air SP = Work SP + Ratio (F) (Work SP – Zone Work Temp)

Where

F = 0.1 to 1 based on the difference between the coldest work temp, the work SP and the selected work temp and work SP.

With the adjustable ratio, the slowest zone will be entirely unaffected by this system. However, a zone that may be heating too fast and in danger of overheating, will be detected early. In this case, the ratio for that specific zone will be automatically reduced. This reduced ratio will lower the zone air set point, resulting in the zone approaching the work set point together with the slowest zone. This should allow all zones in a multi-zone furnace to reach work set point at the same time.

With this system and when there is no difference between the zone work temperatures, the value for F would be 1, thus allowing both zones to utilize the higher, or conventional ratio number.

With conventional ratio, if a zone work temperature goes over the work set point, it may take an extended period of time to bring it back down. The resulting lower air temperature in this zone may depress adjacent zone air temperatures, thus delaying all zones reaching work set point.

This system may allow for higher ratio’s to be used, as the ratio is selected as the greatest number that would minimize the chances for work over heating, generally on the hottest load. Likewise, higher head temperatures may also be considered.

About SECO/WARWICK’s Aluminum Furnace Group

SECO/WARWICK has been involved in the design development and manufacture of aluminum heat processing equipment for over 40 years. The Aluminum Group provides precision engineered equipment for annealing, log homogenizing, ingot heating, solution heat treating, stationary and tilting reverbs, central melt and holding furnaces. The Group sponsors the Aluminum Furnace Seminar twice a year in April and October which provides in-depth information on improving efficiencies and methods to minimize waste and conserve energy through a review of the fundamental principles involved in heat transfer, heating systems, protective atmospheres and process controls. For more information, please visit our website at www.secowarwick.com.

Contact: Beth Ryan, Marketing Services Coordinator

SECO/WARWICK Corporation
P. O. Box 908,180 Mercer St.
Meadville, PA 16335-6908 USA
Phone: +1-814-332-8400
Fax: +1-814-724-1407
E-mail: info@secowarwick.com