Babcock-Hitachi Kabushiki Kaisha

Iwao Kusaka

Toshinori Shigenaka

A waste heat recovery boiler comprising heat exchange rate switching means for controlling the rate of heat exchange between an exhaust gas and feedwater in a heat exchanger by changing the state of the feedwater in accordance with the concentration of sulfur oxides in the exhaust gas, thereby maintaining the temperature at which low temperature corrosion due to the exhaust gas is prevented in a downstream portion of the heat exchanger in the direction in which the exhaust gas flows. Accordingly, it is possible to achieve the maximum efficiency of heat recovery since the phenomenon of steaming in the heat exchanger is eliminated irrespective of whether the kind of exhaust gas is a dirty gas or a clean gas.

Waste heat recovery boiler

Heat recovery boiler equipment comprising high and low pressure boiler drums and high and low pressure evaporators is disclosed. A recirculation pipeline system is also disclosed in which a control device is provided to control the flow rate of recirculated feed water to maintain a temperature below which cold corrosion occurs. The recirculation of feed water allows for a shorter starting time during restart. Additionally, pressure can be held at a predetermined value to prevent corrosion due to the intrusion of air.

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Kure, Japan

Iwao Kusaka