How do we prevent freezing salt in line?

    In order to prevent freezing of salt in the lines during operation, the piping system is equipped with electric heaters to maintain the plumbing at a temperature of 280°C, or 40° above the melting point of the salt. The set point is slightly below the lowest operating temperature of 290°C, which ensures that the trace heaters will turn off while the system is operating. The heat trace temperature control loop is a feedback control loop which uses an electric heater wrapped around the piping and feedback from a k-type thermocouple welded to the piping.
    In order to assist in starting salt flow in the HX, a heat trace heater is also installed in the area of the HX plumbing. The hardware for the heater is not fully defined yet. This heater is responsible for bringing the piping temperature above the freeze point of the salt before the cooling air is turned on and before molten salt is directed to the HX