Author information - This article was prepared through joint efforts between Kalenborn Abresist Corp., Urbana, IN and North Manchester Foundry, North Manchester, IN.
Materials handling plays a key role in the day-to-day operations of every foundry. Whether moving materials into a plant, transferring it within the plant, or shipping finished goods out the door, materials handling is vital to the inner-workings of foundries. The North Manchester Foundry of North Manchester, Indiana, is no exception to this rule.
The facility manufactures and heat-treats an average of 70 tons of rough gray iron, ductile iron, and stainless steel castings per day. The castings are used in wide range of industries including the automotive, agricultural, boating and plumbing industries. The facility uses approximately 50,000 pounds of dry sand per day in their molding processes. The sand, which plays a critical role in determining the strength and hardness of the castings, is pneumatically unloaded from the delivery truck at a pressure of 10-15 psi into a 4" diameter sand transporter line. Pneumatic conveying systems are based on fully or partially aerating the material, such as sand, to push it through a pipeline. In North Manchester Foundry’s case, the pipeline was originally schedule 40 pipe. Eventually, such pneumatic systems are prone to abrasive wear, especially when moving sand, even if extra-heavy pipe is used.
In 1988, the North Manchester Foundry was having problems with the pneumatic system due to excessive abrasion in two 90° elbows. Operations were interrupted on a regular basis so the elbows could be patched and eventually completely replaced. However, this remedy only lasted two years. Joe Brubaker, North Manchester Foundry’s maintenance foreman for the past 24 years, decided that a more permanent solution needed to be found.
“We knew that changing our method of transport (by replacing the pneumatic pipe system) was cost prohibitive,” said Brubaker. “But the elbows were going to continue to wear through because of the impact they sustained as the sand changes direction.”
In 1990, Brubaker was approached by Kalenborn Abresist Corporation, the U.S. Subsidiary of KALENBORN® Kalprotect, the German developer of ABRESIST® abrasion resistant materials. The Urbana, Indiana, company manufactures ALRESIST® high alumina ceramic-lined products made from fine grain, alpha aluminum oxide. The alumina linings are rated 9 on the Mohs hardness scale, higher than any other material with the exception of diamond which is 10.
Working with the foundry, Kalenborn Abresist Corporation designed, fabricated and delivered two 4" ID x 90° elbows, 24" radius. The elbows were lined with 1" thick alumina cylinders installed in 10 gauge steel casings equipped with rotating flanges. Weld-on adaptor flanges were used to connect the oversized flanges to the schedule 40 straight pipe.
According to Kalenborn Abresist sales representative, Gary Hensley, “Abrasion is a common problem at most foundries in the pneumatic conveying of sand. The key to longer life in this abrasive situation was to provide a lining harder than the silica sand, and alumina does that.”
The original ALRESIST® lined elbows were finally replaced in March of 1998 … eight years after the original installation.
“We were extremely pleased with the performance of the ALRESIST® linings,” said Brubaker. “They allowed the elbows to last four times longer than before, which prevented us from shutting down operations at least three times. Anytime you can cut downtime, it’s going to improve your overall productivity.”
Because of the performance of the ALRESIST® lining, it has also been installed in two other elbows in another transporter lines. This transporter line only handles 50,000 pounds of sand per week, so it is expected to last at least 10-12 years.
“We have confidence in the ALRESIST®
linings because they have proven themselves over a long period
of time,“ said Brubaker. “Now we know approximately
how long the elbows will last. This means I can anticipate
and execute a plant shut-down (to replace the linings) much