| 摘要 |
The present invention provides an economizer which can inhibit generation of stress concentration. The economizer comprises: a container; a flue tube which is disposed in a water room of the container, and in which exhaust gas flows; and a casing which forms a passage between the container and the casing. The container includes: a supporting plate which supports the flue tube; a supply port which supplies exhaust gas to the passage; a discharge port which discharges exhaust gas in the passage; a first opening and closing unit which opens and closes the supply port; and a second opening and closing unit which opens and closes the discharge port. In a normal state, the supply port is closed, and the discharge port is closed. In regards to the water room, the supply port is opened by the first opening and closing unit, and the discharge port is opened by the second opening and closing unit in an abnormal state where exhaust gas flows into the flue tube in a state of no water around the flue tube. |
