To make drain water of a latent heat recovering heat exchanger harmless by removing formaldehyde from the drain water, in a condensing hot water supply device.
The formaldehyde is removed from the drain water collected from a secondary heat exchanger 1 for recovering latent heat by decomposition reaction caused by manganese dioxide in a modification tank 4. After the removal, the drain water is neutralized in a neutralization tank 5 and is temporarily reserved in a buffer tank 6. A three way switching valve 17 is opened at the timing that a bathtub 2 is in a nonuse status. The drain water is discharged from the buffer tank to a reheating circulation route 3, flowed into the bathtub through an exterior pipe 30, and discharged from a drain outlet 21 to the outside. The drain water is heated by arranging the modification tank adjacent to a primary heat exchanger 32 and a burner case and adding a heater to increase the treatment speed.
NAKATSUKA YUJI
TAMADA HARUHIKO
ASAKURA HIROSHI
MASUDA HIROKAZU
TSUTSUMI AKIRA
| JP2009150605A | 2009-07-09 | |||
| JPS5223860A | 1977-02-23 | |||
| JPS5345667A | 1978-04-24 |