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.

Unit (11) for feeding a reducing solution from the tank to the exhaust duct of an endothemiic engine is provided. The unit comprises a supporting head (13) arranged for being associated to an aperture provided in a reducing solution tank and a heating device (15) for heating the reducing solution contained in the tank. The heating device (15) extends from the supporting head (13) and is provided with a duct (17) for a heating fluid. The duct (17) is defined by a side wall (31) which, when the unit (11) is in use, is internally in contact with the heating fluid passing through the duct (17) and externally in contact with the reducing solution present in the tank. At least one portion of the wall (31) of the duct (17) is non-smooth inside and/or outside the duct.

A heat exchanger having a first heat exchanger tube and a second heat exchanger tube is disclosed. The first heat exchanger tube can have a first leg, a second leg, and a bend section, and the bend section of the first heat exchanger tube can include three or more bends, each of the three or more bends having a corresponding bend angle that is less than or equal to approximately 90 degrees. The second heat exchanger tube can have a first leg, a second leg, and a bend section, and the bend section of the second heat exchanger tube can include three or more bends, each of the three or more bends having a corresponding bend angle that is less than or equal to approximately 90 degrees.

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 heat exchanger having a first heat exchanger tube and a second heat exchanger tube is disclosed. The first heat exchanger tube can have a first leg, a second leg, and a bend section, and the bend section of the first heat exchanger tube can include three or more bends, each of the three or more bends having a corresponding bend angle that is less than or equal to approximately 90 degrees. The second heat exchanger tube can have a first leg, a second leg, and a bend section, and the bend section of the second heat exchanger tube can include three or more bends, each of the three or more bends having a corresponding bend angle that is less than or equal to approximately 90 degrees.

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.

Disclosed herein is a double tube for heat exchange. The double tube for heat exchange includes: a spiral pipe having ridges and valleys alternately formed on a circumferential surface thereof along a spiral track thereof and guiding a first fluid to flow therethrough; an outer pipe receiving the spiral pipe axially inserted thereinto and guiding a second fluid to flow along the circumferential surface of the spiral pipe in an axial direction such that the second fluid exchanges heat with the first fluid; and a resistance member protruding from the spiral pipe or the valleys to increase residence time of the second fluid in the valleys on the circumferential surface of the spiral pipe and to support the ridges adjacent thereto. Unlike typical double tubes, the double tube for heat exchange can improve heat exchange efficiency between a second fluid flowing inside an outer pipe and a fluid flowing inside a spiral pipe axially inserted into the outer pipe to increase residence time of the second fluid inside the outer pipe by virtue of a spiral shape of the spiral pipe; can improve flow directionality of the second fluid through formation of the grooves in valleys of the spiral pipe along a spiral track of the valleys; can reduce flow-induced noise through expansion of a space defined between an end joint of the outer pipe and the inner pipe to reduce the pressure of the second fluid; and further improve heat exchange efficiency through resistance members protruding from the valleys to increase residence time of the second fluid.

A heat exchanger element for use in a heat exchanger includes an outer wall formed into a tubular shape including a first portion and a second portion. The first portion is arranged parallel to and is spaced apart from the second portion. A plurality of fin structures extends between the first portion and the second portion of the outer wall. Each of the fin structures defines a flow channel configured to provide fluid communication between an outer surface of the first portion of the outer wall and an outer surface of the second portion of the outer wall. An interior of the outer wall is configured to receive a first fluid while an exterior of the outer wall and each of the flow channels defined by the fin structures are configured to receive a second fluid in heat exchange relationship with the first fluid.