To perform reliably, a Blast Furnace tuyere must not only have optimal design, but it must also be produced with very high purity copper to allow for maximum heat transfer. Tallman blast furnace parts are made to x-ray quality standards and by utilizing only the highest purity electrolytic copper, we have among the highest conductivity in the industry. Tallman tuyeres are designed and manufactured to meet and exceed the tough demands of today's modern Ironmaker.
Modern blast furnace operations require tuyeres that can withstand increasingly severe operating conditions. While traditional flooded tuyere designs incorporate a single water inlet and outlet, in the event of nose wear or damage, the water must be shut off and the tuyere must be replaced immediately. Modern, dual flow tuyere designs allow the water to be shut off to the nose section only, allowing the tuyere to be replaced on the next scheduled outage, avoiding an unforeseen delay.
Tallman takes the concept of a dual flow tuyere to the next level with intensive, computer optimized nose cooling designs, including radiused chamber and high velocity spiral designs. In addition, centrifugally cast tuyere noses are available using the same grain refinement technology used in Tallman's EAF and BOF lance tips, to increase wear resistance and improve overall life of the tuyere.
Combining these technologies together with the latest in available hard facing methods, including calorizing, results in state of the art tuyere performance and life.
Today's Ironmaker faces extreme challenges from high revert burdens and throttling requirements brought about by demanding and volatile market conditions. Tallman has responded to the challenge of running furnaces at reduced wind rate by developing a new tuyere insert that combines tremendous toughness and abrasion resistance under extreme high service temperature conditions. In addition, the alloy is centrifugally cast to maximize density and reduce porosity. The alloy has an oxidation rate of less than 0.5mm/year!. These inserts are engineered to provide long term service life at hot blast temperatures up to 2200°F (1200°c).
Blast Furnace tuyeres must perform reliably in the harsh environment they are placed. Standard tuyeres fail prematurely due to iron drips that dissolve the copper and create "Bullet Hole" defects.
Calorizing is a pack diffusion process where the copper tuyere is placed in a sealed retort containing aluminum powder. The casting is heated and aluminum is diffused into the surface, creating a copper aluminide inner layer and an aluminum oxide outer layer.
Calorizing creates a protective layer on the copper tuyere that preventing liquid iron drips from penetrating the surface. The calorizing process is performed at the final stage of production after the tuyere is finished machined and hardfacing alloys are applied. Calorizing eliminates the need to use refractory materials on the top surface of the tuyere.
Content
Calorizing is a pack diffusion process where the copper casting is placed in a sealed retort containing aluminum powder. The casting is heated and aluminum is diffused into the surface, creating a copper aluminide inner layer and an aluminum oxide outer layer.
The Coating is diffused into the copper thereby creating a perfect bond with the copper substrate. The thickness of the coating is approximately 1 mm and consists of three layers:
