A double pipe type heat exchanger includes an inner pipe having a first flow path defined therein and an outer pipe arranged around the inner pipe to define a second flow path between the inner pipe and the outer pipe. The inner pipe includes a spiral groove formed on an outer circumferential surface of the inner pipe to extend along a longitudinal direction of the inner pipe. The outer pipe includes a reduced diameter portion protruding inwardly so that the inner surface of the outer pipe is intermittently contacted with the outer circumferential surface of the inner pipe.

A heating system including at least one louver coupled with the housing of a heater including a blade and end caps on the blade for holding each louver in a fixed position during operation of the heater assembly, but also releasing the louver for adjustment in positioning relative to the axis of rotation of the louver to change air flow direction or other characteristics as desired.

A heat exchanger device for a heater a motor vehicle, having a housing with at least one fluid channel disposed therein, with a fluid inlet and a fluid outlet, an element generating an alternating magnetic field, and at least one, preferably metallic, flat heating element around which a fluid can flow on one or both sides, whereby at least one further flat heating element is provided, which is configured to divide the at least one fluid channel into subchannels. A heater with a heat exchanger device is also provided.

A heat exchanger device for a heater a motor vehicle, having a housing with at least one fluid channel disposed therein, with a fluid inlet and a fluid outlet, an element generating an alternating magnetic field, and at least one, preferably metallic, flat heating element around which a fluid can flow on one or both sides, whereby at least one further flat heating element is provided, which is configured to divide the at least one fluid channel into subchannels. A heater with a heat exchanger device is also provided.

A heat exchanger includes fins each housed in a respective one of tubes. Each of the fins includes a connecting portion that corrugated for a predetermined fin pitch and that has peaks joined to an inner surface of a wall of each of the tubes and a non-connecting portion that is not joined to the inner surface of the wall of the each of the tubes. The non-connecting portion has a length longer than the predetermined fin pitch. The wall of the each of the tubes has a protrusion to face the non-connecting portion.

A heat exchanger includes fins each housed in a respective one of tubes. Each of the fins includes a connecting portion that corrugated for a predetermined fin pitch and that has peaks joined to an inner surface of a wall of each of the tubes and a non-connecting portion that is not joined to the inner surface of the wall of the each of the tubes. The non-connecting portion has a length longer than the predetermined fin pitch. The wall of the each of the tubes has a protrusion to face the non-connecting portion.

A fermentation tank includes a tank body, enclosing a cavity therein, having a material inlet and a material outlet; a heat exchange structure, disposed on a wall of the cavity for heat exchanging with the tank body; at least one flow disturbing plate, being an elongated plate, the width direction of the flow disturbing plate being parallel to a radial direction of the tank body, the longitudinal direction of the flow disturbing plate being parallel to a vertical direction, a length of the flow disturbing plate being larger than a width thereof, the flow disturbing plate being arranged in the cavity and connected to the tank body, the flow disturbing plate having a heat exchange channel therein, two ends of the heat exchange channel communicating an exterior respectively so that heat is exchanged between the at least one flow disturbing plate and the cavity.

A fermentation tank includes a tank body, enclosing a cavity therein, having a material inlet and a material outlet; a heat exchange structure, disposed on a wall of the cavity for heat exchanging with the tank body; at least one flow disturbing plate, being an elongated plate, the width direction of the flow disturbing plate being parallel to a radial direction of the tank body, the longitudinal direction of the flow disturbing plate being parallel to a vertical direction, a length of the flow disturbing plate being larger than a width thereof, the flow disturbing plate being arranged in the cavity and connected to the tank body, the flow disturbing plate having a heat exchange channel therein, two ends of the heat exchange channel communicating an exterior respectively so that heat is exchanged between the at least one flow disturbing plate and the cavity.

A heat transfer fin (1) includes a plurality of heat-transfer-tube insertion holes (10) aligned in a single stage, a downstream cut portion (3) formed so as to be recessed toward an upstream side of a gas flow passage of combustion exhaust gas, a downstream flange (13) formed on a peripheral edge of the downstream cut portion (3) so as to protrude from one surface of the heat transfer fin (1), and a plurality of first protruding pieces (4a) (4b) (4c) formed between the heat-transfer-tube insertion hole (10) and the downstream flange (13) so as to protrude alternately from both surfaces of the heat transfer fin (1).

A finned tube (e.g., for use in a flooded and falling film evaporator) is provided. The finned tube includes a tube body with an interior surface and an exterior surface. The finned tube may include a plurality of adjacent helical fins (e.g., continuously or intermittently) protruding circumferentially around the exterior surface of the tube body. At least one channel is disposed between the plurality of adjacent helical fins. Each respective helical fin includes at least one sidewall and a fin top. Each channel includes at least one channel enhancement impressed radially into and transversely through at intervals around the circumference of the exterior surface of the tube body. The finned tube may also include at least one top enhancement and/or sidewall enhancement impressed radially into and transversely through at intervals around the circumference of the exterior surface of the tube body.