HEAT EXCHANGER

PROBLEM TO BE SOLVED: To provide a heat exchanger capable of appropriately preventing a large quantity of drain water generated to follow heat recovery from stagnating on a bottom wall of a case by simple means.SOLUTION: A heat exchanger HE includes a drain water guide 4 including a horizontal plate portion 40 generally horizontal and located on an upper side of an upper stage portion 22a of a bottom wall 22 of a case 22 containing heat transfer tubes 1. Between the upper stage portion 22a and the horizontal plate portion 40, a capillary gap 5 including a first side surface opening portion 51 that is located on the upper stage portion 22a and through which drain water in contact with an edge of the horizontal plate portion 40 can be attracted inside is formed. This capillary gap 5 also includes a second side surface opening 52 opening on an edge 22a' of the upper stage portion 22a so that the drain water attracted inside can flow down from the upper stage portion 22a toward a lower stage portion 22b. 【課題】熱回収に伴って発生するドレン水がケースの底壁部上に多量に滞留することを、簡易な手段によって適切に防止することが可能な熱交換器を提供する。【解決手段】熱交換器ＨＥは、伝熱管１を収容するケース２の底壁部２２のうち、上段部２２ａの上側に位置する略水平状の水平板部４０を有するドレン水ガイド４を備えており、上段部２２ａと水平板部４０との間には、上段部２２ａ上に位置して水平板部４０の縁部に接触するドレン水を内部に引き込むことが可能な第１の側面開口部５１を有するキャピラリ隙間５が形成されており、かつこのキャピラリ隙間５は、内側に引き込まれたドレン水を上段部２２ａから下段部２２ｂ側に流れ落とすことが可能なように、上段部２２ａの縁部２２ａ'上において開口する第２の側面開口部５２をさらに有している。【選択図】 図２