IMIDAZOLYL-UREA COMPOUND, CURING PROMOTER OF CURABLE COMPOSITION COMPOSED THEREOF, CURABLE EPOXIDE RESIN COMPOSITION AND EPOXIDE RESIN MOLDED BODY

摘要

PURPOSE:To control the level of a feedwater heater nicely by a method wherein an emergency level adjusting valve is preceded to open and the forced closing of a normal level adjusting valve is delayed by a timer when the operation thereof is transferred to the independent load operation in a plant by a load interception. CONSTITUTION:The level of a first high-pressure feedwater heater 12 is detected by a level transmitter 20 while normal and emergency adjusting valves 23, 24 are controlled through normal and emergency adjusting meters 21, 22. When the operation is transferred to the independent load operation in the plant by the interception of the load, an FCB signal is introduced into a three-way solenoid valve 81 and the emergency level adjusting valve 24 is opened immediately to suppress the rise of the level. On the other hand, the FCB signal is introduced into the three-way solenoid valve 80 through the timer 82 and the normal level adjusting valve 23 is closed forcibly. Thus, the bypass operation of the feed water heater due to the rise of the levels of the first and second high-pressure feedwater heaters 11, 12 may be interrupted and the stable level control may be effected.