Apparatus for the controlled heating of process fluids

摘要

An apparatus for the controlled heating of a process fluid has a heater, a process fluid vessel containing the process fluid, and a bundle of thermosyphons extending between a burner chamber of the heater and the process fluid inside the vessel for transferring heat from the heater to the process fluid. Burners in the burner chamber are controlled to maintain the bulk temperature of the process fluid TBULK substantially within an operating range defined by preset upper THIGH and lower TLOW temperature setpoints. The burners can be turned on to maintain an outside metal temperature TEVAP of the evaporator ends of the thermosyphons above a preset dew point temperature TDEW to prevent corrosion. The burners can also be shut down if an outside surface temperature TOD of at least one of the condenser ends of the thermosyphons extending into the vessel exceeds a predetermined setpoint temperature TALARM. Different configurations of condenser ends of the thermosyphons in the vessel may be utilized to enhance heating the process fluid. The vessel and heater are separated and sealed from each other by a sealed chamber encasing the thermosyphons, which may also be used to preheat incoming combustion air for the burners.