DURALOY TECHNOLOGIES, INC. | CSP TUNNEL ROLLS

more steel mill products

back to "about duraloy"

tunnel rolls market1 tunnel furnace end bells

CSP DRY TUNNEL FURNACE ROLLS

DURALOY INTRODUCES DRY ROLLS FOR USE IN HEATING ZONES

Traditionally, dry rolls have been confined to the shuttle sections of Hot Mill tunnel furnaces. Water-cooled rolls were thought to be necessary in the higher temperature heating zones, and were perceived to be the “cheaper” roll option.

When the cost of natural gas was in the $2 per mmBtu range, the idea that water-cooled rolls were less costly was reasonable. However, as gas costs have risen (over $11 per mmBtu as of May ’08), this notion has come in to question, and heat loss studies have shown this to be anything but the truth.

Introduction by Duraloy of its MORE-2150^® alloy, along with improved roll designs, and recent innovations in welding have enabled the use of DURALOY dry rolls in areas of tunnel furnaces once thought to be out of bounds for dry rolls.

With regard to energy savings, water-cooled rolls have been documented to waste as much as 250,000 Btu/hour for each roll in the furnace. This occurs as cooling water--heated during its cycle through the roll--is discharged from the furnace. In comparison, dry rolls typically loose less then 7% the amount of heat as do water-cooled rolls.

When combustion system efficiency is taken in to consideration, the amount of gas wasted by a single water-cooled roll is on the order of 400,000 Btu each hour of operation. Annually this amounts to over 3000 mmBtu of gas at a cost of $23,000 to over $30,000 per roll depending on the prevailing cost of natural gas. For a furnace equipped with 100 water-cooled rolls, this waste can add up quickly; from $2 million to $3 million dollars in wasted gas each year. During their typical lifetime (3 to 5 years) a furnace full of MORE 2150^® dry rolls can potentially save anywhere from $6 million to $9 million in natural gas costs. You will compound these savings even more when you factor in the reduction in maintenance costs for rolls and your water supply system and further you will enjoy substantial return credit value on dry rolls at the end of their service life due to the alloy content of the rolls.

Don’t let energy wasting water cooled rolls continue to cost you huge energy bills. Let Duraloy evaluate your water-cooled rolls for possible replacement with Duraloy MORE 2150^® dry rolls. The energy savings that can be achieved will quickly pay for the rolls and ultimately provide the opportunity to increase operating profits by millions of dollars annually. For further information contact Jim Echlin at Duraloy Technologies, Inc. 120 Bridge Street Scottdale, PA 15683. You can each him by e-mail by clicking Here.

DURALOY RECEIVES LARGE ORDERS FOR MO-RE 2150^Ò DRY TUNNEL FURNACE ROLLS FOR HEATING ZONE.

Duraloy has long been the leading supplier of dry rolls for the shuttle sections of CSP tunnel furnaces. Beginning in 1991, DURALOY furnished the first ever dry tunnel furnace rolls and has since supplied thousands of our Super 22H^® rolls for this application. More recently, DURALOY metallurgists developed MORE-2150^® - a new breed of high temperature alloy capable of extending the use of dry rolls well into the heating sections of CSP tunnel furnaces.

Working with our customers our foundry and design engineers have developed rolls specifically designed for heating zone use, and to date we have received 12 orders for 624 MORE-2150^® rolls.

Two of our customers have ordered a sufficient number of rolls to fully eliminate all water-cooled rolls from their furnaces, and at least two others are currently contemplating making such commitments.

One of these customers has completed the change over to dry rolls in one of their two furnaces, making it the first in the world with 100% dry rolls. Later this year, their second furnace will likewise be converted—both furnaces will be equipped exclusively with Duraloy MORE 2150^® dry rolls. For their first conversion, that customer reports energy savings as projected, with no adverse quality or other operating issues.

Another of our customers reported that with water-cooled rolls, their burners were firing at 100% of capacity and unable to achieve set point temperature. After installation of DURALOY dry rolls, set point temperature was achieved at a firing rate of only 18%.

The energy savings implications of this are obvious! With natural gas costs pushing $11 per mmBtu and it seems unlikely that energy costs will drop significantly any time soon, isn’t it time for you to explore Duraloy MORE 2150^® dry roll options as well? For further information contact Jim Echlin at Duraloy Technologies, Inc. 120 Bridge Street Scottdale, PA 15683. You can each him by e-mail by clicking Here.

Leading Edge Dry Roll Technology for Roller Hearth Furnaces

Duraloy has been awarded another large order for an entire tunnel furnace of their proprietary design dry rolls. The rolls are the largest diameter ever used in this application.

Duraloy partnered with the client to define the energy savings that could be achieved via dry roll substitution and to justify the installation of these rolls as opposed to the water-cooled rolls that were originally considered. It was determined that the energy savings being afforded by these rolls would conform to acceptable ROI standards.

This customer’s operation involves a combination of unusually high slab loading and furnace temperature, which dictated the use of larger diameter dry rolls. These will represent the largest diameter dry tunnel furnace rolls ever used. Duraloy engineered these rolls, taking into account the customer’s larger and heavier slab weights, high operating temperatures and their requirement of a multi-year lifetime, utilizing proprietary MO-RE 2150^® material. The rolls also incorporate Duraloy’s specialized internal heat flow barrier system to minimize heat loss through the roll ends and to promote cooler bearing operation.

MO-RE 2150^® was developed by Duraloy specifically for tunnel furnace roll applications, and features high creep strength with exceptional oxidation resistance and surface stability so as to allow dry roll operation at temperatures exceeding 2200°F. Since its introduction just over two years ago, Duraloy has sold over 1000 dry rolls using MO-RE 2150^® barrels as replacements for water-cooled rolls. Collectively, it is estimated that all of the Duraloy dry rolls presently installed at locations worldwide, will afford major savings to our customers through reductions in purchases of millions of cubic feet of gas annually.

Development of MO-RE 2150^® alloy is an extension of previous collaborative efforts with Oak Ridge National Laboratory which were sponsored by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Industrial Technologies Program, Industrial Materials for the Future. The alloys improved performance is due to a unique microstructure developed through the use of computational thermodynamics based on a detailed understanding of the composition-microstructure-property relationships. Duraloy has made significant progress in understanding the relationship between precipitation and creep properties of these alloys through using a combination of thermodynamic modeling, microstructural characterization, and mechanical property measurements.

For further information contact Jim Echlin at Duraloy Technologies, Inc. 120 Bridge Street Scottdale, PA 15683. You can each him by e-mail by clicking Here.

duraloy^®, THE DURALOY LOGO, MO-RE^®, SUPERTHERM^®, TMA^®, 22H^®, and Super 22H^® are registered trademarks of Duraloy Technologies, Inc., in the United States, Canada and the European Community. All Rights Reserved.