Patent ID: 7955587

Claim:
A method for the energy efficient production of calcined gypsum, the method being carried out in a board plant including a board dryer, a stack, and a condenser that is thermodynamically coupled to the stack, the method comprising the following steps: drying a gypsum building board within the board dryer, whereby excess moisture within the board is evaporated; removing the evaporated moisture from the dryer via the stack, the evaporated moisture being removed as steam; condensing the removed steam via the condenser to form hot condensate and collecting the hot condensate; mixing the collected hot condensate with raw gypsum whereby the resulting gypsum slurry has a temperature of between approximately 140° F. to 160° F.; calcinating the heated gypsum slurry wherein the calcinating temperature is more efficiently achieved via the addition of the hot condensate.