L&L Special Furnace Co. Inc. delivered a second car-bottom furnace that will be used for curing complex ceramic composites, silicon-carbide plates and military-grade armaments. The cycles require extremely slow heat-up and cool-down curves, which are critical for the end product. Some of the heating and cooling curves are as slow as 2°C per hour up to 1010°C. The furnace has an effective work area of 76 inches wide x 48 inches high x 120 inches deep. This allows for many different parts and load configurations to be processed in each thermal cycle.
The curing process is achieved by heating the parts very slowly to drive off moisture without affecting the part integrity. Temperature uniformity is critical for this process, and both ambient and load temperature must maintain ±10°F throughout the cycle.
There are two 18-inch-diameter air-cooled fans to provide temperature uniformity of ±5.5°C throughout the thermal cycle, along with 12 separate SSR power controls with digital biasing for balancing any temperature gradients as required.
The parts are loaded onto the furnace car bottom (load weights can exceed 10,000 pounds). The furnace car bottom can be accessed from both sides and has an electric drive motor that moves the car in and out of the furnace on railroad rails. There are a series of high-density castable piers that allow for forklift or overhead loading.