A burn box includes a font, a rear, a first and a second side, a lower, and an upper interior surface, as well as a first push member, a first coupler, and a first torque member. The first push member includes a first end, a second end, and a first coupler portion. The first coupler pivotally couples the first coupler portion to the first interior surface. The second end is vertically intermediate the first end and the lower interior surface. The first torque member provides a first torque to the first push member. When the first torque is provided to the first push member, the first push member rotates about a first rotational axis. The first rotational axis is through the first coupler portion of the first push member. The first rotational axis is parallel to the longitudinal axis. The second end rotates toward the second side interior surface.

A burn box includes a font, a rear, a first and a second side, a lower, and an upper interior surface, as well as a first push member, a first coupler, and a first torque member. The first push member includes a first end, a second end, and a first coupler portion. The first coupler pivotally couples the first coupler portion to the first interior surface. The second end is vertically intermediate the first end and the lower interior surface. The first torque member provides a first torque to the first push member. When the first torque is provided to the first push member, the first push member rotates about a first rotational axis. The first rotational axis is through the first coupler portion of the first push member. The first rotational axis is parallel to the longitudinal axis. The second end rotates toward the second side interior surface.

A condensing combustion apparatus comprising: an upward combustion burner (20); a sensible-heat exchanger (40) which absorbs sensible combustion heat generated by the burner (20); and a latent-heat exchanger (50) which absorbs latent heat of steam included in a combustion gas which has passed the sensible-heat exchanger (40), wherein the sensible-heat exchanger (40) and the latent-heat exchanger (50) have the same lateral widths and are configured as fin-tube heat exchangers having common structures, and wherein a flow path through which the combustion gas, which has passed the sensible-heat exchanger (40), flows upward is formed on one side portion of the latent-heat exchanger (50), a flow path through which the combustion gas, which has passed the one side portion of the latent-heat exchanger (50), flows downward corresponding to a direction in which condensed water falls is formed on a middle portion of the latent-heat exchanger (50), and a flow path through which the combustion gas, which has passed the middle portion of the latent-heat exchanger (50), flows upward and discharges is formed on another side portion of the latent-heat exchanger (50).

A condensing combustion apparatus comprising: an upward combustion burner (20); a sensible-heat exchanger (40) which absorbs sensible combustion heat generated by the burner (20); and a latent-heat exchanger (50) which absorbs latent heat of steam included in a combustion gas which has passed the sensible-heat exchanger (40), wherein the sensible-heat exchanger (40) and the latent-heat exchanger (50) have the same lateral widths and are configured as fin-tube heat exchangers having common structures, and wherein a flow path through which the combustion gas, which has passed the sensible-heat exchanger (40), flows upward is formed on one side portion of the latent-heat exchanger (50), a flow path through which the combustion gas, which has passed the one side portion of the latent-heat exchanger (50), flows downward corresponding to a direction in which condensed water falls is formed on a middle portion of the latent-heat exchanger (50), and a flow path through which the combustion gas, which has passed the middle portion of the latent-heat exchanger (50), flows upward and discharges is formed on another side portion of the latent-heat exchanger (50).

A fin-and-tube type heat exchanger includes: a plurality of plate fins arranged in a case side by side in a fore-and-aft direction of the case; and a heat transfer tube including a plurality of straight-type tubular bodies each passing through these plurality of plate fins. First and second plate fins arranged side by side in the right-and-left width direction of the case are provided as a plurality of plate fins. The heat transfer tube has a connection tubular body connecting the straight-type tubular bodies passing through the first and second plate fins. The heat transfer tube passes through areas in which the first and second plate fins are arranged.

A fin-and-tube type heat exchanger includes: a plurality of plate fins arranged in a case side by side in a fore-and-aft direction of the case; and a heat transfer tube including a plurality of straight-type tubular bodies each passing through these plurality of plate fins. First and second plate fins arranged side by side in the right-and-left width direction of the case are provided as a plurality of plate fins. The heat transfer tube has a connection tubular body connecting the straight-type tubular bodies passing through the first and second plate fins. The heat transfer tube passes through areas in which the first and second plate fins are arranged.

According to the present invention, a heat exchanger comprises a fin having a plurality of through holes. The plurality of through holes include mutually adjacent first and second through holes disposed on a side closest to a heating gas's inlet side. The fin has a slit located between the first through hole and the second through hole and cut into the fin from an edge thereof located on the heating gas's inlet side to a side farther from the heating gas's inlet side than a reference line connecting a center of the first through hole and a center of the second through hole. Furthermore, the fin has at least one opening between the slit and the first and second through holes. The opening includes a first opening having a portion located on the side farther from the heating gas's inlet side than the reference line.

A burn box includes a font, a rear, a first and a second side, a lower, and an upper interior surface, as well as a first push member, a first coupler, and a first torque member. The first push member includes a first end, a second end, and a first coupler portion. The first coupler pivotally couples the first coupler portion to the first interior surface. The second end is vertically intermediate the first end and the lower interior surface. The first torque member provides a first torque to the first push member. When the first torque is provided to the first push member, the first push member rotates about a first rotational axis. The first rotational axis is through the first coupler portion of the first push member. The first rotational axis is parallel to the longitudinal axis. The second end rotates toward the second side interior surface.

A burn box includes a font, a rear, a first and a second side, a lower, and an upper interior surface, as well as a first push member, a first coupler, and a first torque member. The first push member includes a first end, a second end, and a first coupler portion. The first coupler pivotally couples the first coupler portion to the first interior surface. The second end is vertically intermediate the first end and the lower interior surface. The first torque member provides a first torque to the first push member. When the first torque is provided to the first push member, the first push member rotates about a first rotational axis. The first rotational axis is through the first coupler portion of the first push member. The first rotational axis is parallel to the longitudinal axis. The second end rotates toward the second side interior surface.

A heat exchanger includes: a case which has a first side wall that stands upright in a vertical height direction and to which a heating medium is supplied inside; and heat transfer tubes for heating hot water housed in the case. Two end portions of the heat transfer tubes in a longitudinal direction are joined to the first side wall via brazing portions, and the heat transfer tubes are supported by the first side wall. The heat exchanger further includes heat transfer tube support portions provided on the first side wall for supporting portions of the heat transfer tubes near the first side wall to prevent the portions of the heat transfer tubes near the first side wall from descending below a first predetermined height.