McConway & Torley, LLC
Lining Configuration: The austenitizing furnace operates at approximately 1750°F and is approximately 13’ L x 12’ W x 8’ H with a complete ceramic fiber lining. The sidewalls, door and roof are 8” thick fiber module construction.
Customer Need: Norheat Treatment Inc./ITC recommended a solution to address several major challenges including:
- Excessive heat loss and shell temperatures on the roof and sidewalls
- High fuel usage
- Continual refractory maintenance within all zones
Engineered Approach: Norheat Treatment Inc./ITC recommended applying a proprietary high temperature, energy efficient ceramic coating on the hot face of the refractory insulation to eliminate shrinking and devitrification of the ceramic fiber and hot spots on the furnace shell. The project consisted of coating the entire furnace sidewalls, door and roof.
High Temperature Energy Efficient Ceramic Coatings: Norheat Treatment Inc. supplies a proprietary, high temperature, energy efficient ceramic coating to work in concert with the furnace conditions and all types of refractory design. Under ideal conditions, high temperature, energy efficient ceramic coatings absorb energy from the process and re-radiate it to the furnace load, imparting the following benefits:
- Lower Heat Loss – Minimizes heat transfer through the furnace refractory walls
- Lower Maintenance Costs – Protects the substrate refractory
- Improved Furnace Operation – Improves the thermal efficiency of the process
IMPACT ON THE PROCESS
Lower Shell Temperatures – The high temperature energy efficient ceramic coatings that protect the fiber from shrinking and devitrification, have lowered shell temperatures and hot spots.
Improved BTU Savings – Due to the re-radiating properties of the coating, Btu savings are significantly better than uncoated fiber refractory. Temperature loss within the furnace has been reduced and temperature uniformity has become more consistent. Temperature uniformity before and after application of the coatings was +/- 400°F verses +/- 250°F respectively.
Reduced Fuel Consumption – Prior to coating application fuel consumption per load averaged 20.8 MCF. After coating application, fuel consumption dropped to an average of 18.7 MCF per load.
Reduced Refractory Maintenance – Protection from the coating helps eliminate ceramic fiber from shrinking and devitrification thus reducing the amount of time and material need to keep the furnace operational.
Increased Refractory Longevity – Once the coating is applied, refractory life is increased by 3 to 5 times its normal life expectancy.
Reduced Turnaround Times –After the application of the coating, turn around time was reduced by 20 minutes. This equates to one additional 5 ton load processed per week. Each 5 ton load adds an additional $10,000 in sellable product per week or a potential increase in yearly revenue of $480,000 plus. $10,000 x 4 weeks/month x 12 months/year = $480,000 per year.
IMPACT ON BOTTOM LINE COSTS
Fuel Savings = 20.8 MCF – 18.7 MCF = 2.1 MCF per load or 10% reduction
Increased Production = Potential increase in yearly revenue of $480,000 per year plus = One additional 5 ton load per week (4 weeks/month) (12 months/year) ($10,000/week)
Heat Loss = Temperature uniformity improved with application of coatings, +/- 400°F verses +/- 250°F which equals approximately a 46% change.