Apparatus and method for producing melamine

Claim 1

A PROCESS FOR THE CONTINUOUS PRODUCTION OF MELAMINE WHICH COMPRISES CONTINUOUSLY INJECTING MOLTEN UREA INTO MOLTEN MELAMINO IN THE BOTTOM PORTION OF A VERTICALLY ARRANGED PRESSURE-RESISTANT REACTION VESSEL, WHICH MOLTEN MELAMINE IS CONTINUOUSLY FLOWING IN A SUBSTANTIALLY VERTICAL DIRECTION, TO FORM A VERTICALLY RISING SUSPENSION OF UREA IN MELAMINE IN WHICH SUSPENSION SAID UREA AND INTERMEDIATE PRODUCTS DERIVED THEREFROM ARE OUT OF CONTACT WITH WALLS OF SAID REACTION VESSEL, SAID MELAMINE BEING AT A TEMPERATURE ABOVE 400*C. TO MAINTAIN THE RESULTING SUSPENSION IN A FLUID STATE AND TO CONVERT SAID UREA TO MOLTEN MELAMINE WITHIN SAID REACTION VESSEL, WHEREBY THE INJECTED UREA IS SUBSTANTIALLY ALL CONVERTED TO MELAMINE AND GASEOUS BY-PRODUCTS WHICH FORM BUBBLES IN SAID MOLTEN MELAMINE, ALLOWING THE RISING STREAM OF MOLTEN MELAMINE TO OVERFLOW CONTINUOUSLY FROM THE TOP PORTION OF SAID REACTION VESSEL, CONTINUOUSLY SEPARATING THE NON-DISSOLVED GASEOUS BY-PRODUCTS FROM THE OVERFLOWING MOLTEN MELAMINE, ALLOWING THE RESULTING MOLTEN MELAMINE TO FLOW CONTINUOUSLY DOWNWARDLY TO A LEVEL BELOW SAID VESSEL AND THENCE UPWARDLY TO THE BOTTOM PORTION OF SAID REACTION VESSEL, CONTINUOUSLY REMOVING A PORTION OF THE MOLTEN MELAMINE BEFORE IT REACHES SAID REACTION VESSEL, CONTINUOUSLY SUPPLYING HEAT TO THE REMAINDER OF THE MOLTEN MELAMINE JUST PRIOR TO ITS ENTRANCE INTO THE BOTTOM PORTION OF SAID REACTION VESSEL TO RAISE THE TEMPERATURE OF THE MOLTEN MELAMINE ABOVE 400*C., THIS BEING THE SOLE SOURCE OF HEAT FOR THE MOLTEN MELAMINE IN SAID REACTION VESSEL, AND CONTINUOUSLY MAINTAINING THE PRESSURE ON THE MOLTEN MELAMINE ABOVE 2000 POUNDS PER SQUARE INCH ABSOLUTE BY CONTROLLING THE AMOUNT OF GASEOUS BY-PRODUCTS RELEASED.