Abstract: The invention relates to a heat exchanger with a temperature sensor and especially a heat exchanger usable for heating hot water using district heating water. The heat exchanger (1) contains plates (2) placed in a pack and brazed together so that 5 separate channels for first (Fj) and second (VV) media are formed between alternate pairs of plates; two pairs of connections for inlet (3) and outlet (4) for the first medium and inlet (5) and outlet (6) for the second medium, respectively; and a temperature sensor (9) connectable to a valve (7) to control supply of the first medium through the heat exchanger. The first medium is intended to supply heat to 10 the second medium. The temperature sensor (9) is placed through a number of plates and in heat conducting contact with them such that the temperature sensor controls the first valve.

Abstract: This invention relates to a spiral heat exchanger including a spiral body formed by at least one spiral sheet wound to form a first spiral-shaped flow channel for a first medium, and a second spiral-shaped flow channel for a second medium. The spiral body is enclosed by a substantially cylindrical shell with connection elements communicating with the first flow channel and the second flow channel. The shell includes at least two shell parts, and the spiral body is provided with at least one fixedly attached flange on its outer peripheral surface, whereupon the at least two sell parts are removably attached.

Abstract: An HVAC duct or utilicore for substantially containing air flowing longitudinally therethrough has at least one wall comprised of a poured high thermal mass material with at least one pipe embedded therein during a pouring process, the at least one pipe for circulating a fluid throughout the at least one wall at a temperature that is different from an ambient temperature of the air flowing through the utilicore, for effecting heat transfer through the at least one wall between the fluid in the at least one conduit and the air flowing through the utilicore. A side wall of an elongate monolithic poured concrete building construction module, having a substantially planar main wall and at least one side wall extending substantially parallel to a longitudinal axis, having a pipe embedded therewithin, may form at least a portion of an element that defines the utilicore.

Abstract: A cylindrical heat exchanger for use as a gas cooler in a thermal regenerative machine such as a Stirling engine includes an imperforate middle wall of sufficient strength and thickness to withstand the pressure exerted by the working fluid. The heat exchanger includes an inner corrugated wall located within an axial gas flow passage inside the middle wall, and an outer corrugated wall which defines an axial coolant flow passage along the outer surface of the middle wall. The coolant flow passage preferably contains a corrugated intermediate wall.

Abstract: A heat exchanger comprising substantially square (rectangle) conduits featuring a screw like turbulator designed for square conduits. The tubes are designed for reclaiming heat from waste fluids. The tubes are substantially parallel to the flow direction of the waste fluid, thus resulting in a simple and cost effective construction.

Abstract: A heat exchanger for an internal combustion engine includes a first flow channel; a second flow channel arranged adjacent to the first flow channel; a line separate from the second flow channel; and a valve channel in which an adjustable valve element is disposed. The valve channel is arranged upstream of the first and second flow channels and an inlet channel is arranged upstream of the valve channel in a flow direction of exhaust gas. The valve element includes a baffle plate, the baffle plate having an end portion that extends diagonally in the valve channel with respect to the flow axis of the first flow channel. The valve element includes a flap that is pivotably mounted at the end portion of the baffle plate such that the flap is pivotable about an axis that extends in a direction of a width of a common housing.

Abstract: The present invention generally includes a coupling between components. When igniting a plasma remote from a processing chamber, the reactive gas ions may travel to the processing chamber through numerous components. The reactive gas ions may be quite hot and cause the various components to become very hot and thus, the seals between apparatus components may fail. Therefore, it may be beneficial to cool any metallic components through which the reactive gas ions may travel. However, at the interface between the cooled metallic component and a ceramic component, the ceramic component may experience a temperature gradient sufficient to crack the ceramic material due to the heat of the reactive gas ions and the coolness of the metallic component. Therefore, extending a flange of the metallic component into the ceramic component may lessen the temperature gradient at the interface and reduce cracking of the ceramic component.

Abstract: A vehicle air handling system includes an air handler, a desiccant assembly and a regeneration mechanism. The air handler has an air inlet configured to receive airflow into the air handler and an air outlet configured to direct the airflow from the air handler to a passenger compartment of a vehicle. The desiccant assembly is installed in a fixed non-movable orientation within the air handler. The desiccant assembly is configured to absorb moisture from the airflow and is disposed between the air inlet and the air outlet. The desiccant assembly includes a first flow path and a second flow path separated from one another such that the airflow passes through the first flow path. The regeneration mechanism is in fluid communication with the second air flow path of the desiccant assembly and is configured to remove moisture from the airflow passing through the desiccant assembly.

Abstract: Disclosed is an economizer including a plurality of coil stacks. Each coil stack includes a tube coiled such that adjacent layers of the tube contact one another in a radial direction. Further, the coil stacks are axially spaced from one another to allow exhaust to flow between adjacent coil stacks.

Abstract: A wound tube heat exchanger 10 article that receives a heat exchange fluid and its method of manufacture. The exchanger 10 has one or more layers 12 of a tube 14. In one embodiment, the tube surface is bare. In other embodiments, the outside tube surface is enhanced to produce turbulence. At least some of the layers 12 have an ovate oblong configuration. A pair of opposing linear runs 16,18 is connected by a pair of opposing curved sections 20,22. In some embodiments, the layers are circular, oval or rectangular with radiused corners. An elongate spacer member 24 has forwardly 26 and rearwardly 28 facing edges. Defined within those edges are engagement surfaces 30 that detachably retain the opposing linear runs 16,18.

Abstract: A heat exchange tube is constructed by forming, on a cylindrical tube peripheral wall, a plurality of projecting portions which project to an inside of the tube peripheral wall, and which are formed by pushing. The plurality of projecting portions are formed, respectively, into conical shapes across a tube axis, and are arranged along virtual spirals on the tube peripheral wall. Accordingly, it is possible to provide a heat exchange tube which facilitates formation of a plurality of projecting portions with the thickness hardly changed and without formation of protruded portions, and which is capable of contributing to enhancement of heat exchanging efficiency.

Abstract: A heat exchanger for a vehicle is disclosed. The heat exchanger may include: a heat radiating portion provided with first and second connecting lines formed alternately by stacking a plurality of plates, and receiving first and second operating fluids respectively into the first and second connecting lines, the first and second operating fluids heat-exchanging with each other during passing through the first and second connecting lines; and a bifurcating portion connecting an inflow hole for flowing one operating fluid of the first and second operating fluids with an exhaust hole for exhausting the one operating fluid, adapted for the one operating fluid to bypass the heat radiating portion according to a temperature of the one operating fluid, and mounted at an exterior of the heat radiating portion.

Abstract: A system for exchanging heat includes a plurality of adjacent envelopes, wherein each envelope defines a plurality of volumes. A connection between adjacent envelopes provides fluid communication between the volumes in adjacent envelopes, and a fluid passage outside of the envelopes and defined by adjacent envelopes extends across a dimension of the system. A method for exchanging heat includes flowing a plurality of secondary fluids through a plurality of volumes in adjacent envelopes, wherein each secondary fluid flows through a separate volume in each envelope. The method further includes flowing a primary fluid through a plurality of channels outside of the adjacent envelopes and defined by the adjacent envelopes.

Abstract: A vacuum insulator for portions of the refrigeration cycle of a refrigerator appliance is provided. The vacuum insulator can be applied to the suction line leading to the refrigerant compressor, the capillary tube leading to the evaporator inlet, and/or the capillary tube—suction line heat exchanger. An outer insulating layer is used to create a vacuum that serves to insulate the intended portion of the refrigeration cycle.

Abstract: A ceramic heat exchanger includes a heat exchange section that heat-exchanges between two fluids A and B flowing opposite directions to each other. The heat exchange section includes ceramic blocks stacked one on top of another with a seal therebetween. The ceramic blocks have a plurality of parallel lines of flow channels, each line defined by the flow channels through which the same fluid flows, any two adjacent lines being defined by the flow channels through which the different fluids A and B flow respectively. Both ends in the stacking direction of the stack are bound to join and integrate the ceramic blocks with tightening means including end plates and a tie rod. A thermal expansion absorber is disposed on an external surface of the end plates for absorbing thermal expansion in the axial direction of the tie rod.

Abstract: A spiral heat exchanger includes a spiral body formed by at least one spiral sheet wound to form the spiral body forming at least a first spiral-shaped flow channel for a first medium and a second spiral-shaped flow channel for a second medium, wherein the spiral body is enclosed by a substantially cylindrical shell being provided with connecting elements communicating with the first flow channel and the second flow channel, where the at least one spiral sheet comprises a corrugated heat transfer surface with corrugations for increasing the heat transfer and supports for spacing the wounds of the at least one spiral sheet in the spiral body.

Abstract: A heat exchanging element adapted to a fuel cell system includes a plurality of heat exchanging units and a fixing unit. The heat exchanging units are arranged to be spaced apart from one another along a first direction. The fixing unit fixes the heat exchanging units. Each of the heat exchanging units is demarcated into a first part and a second part extending from the first part by the fixing unit. A thermal conductivity coefficient of each of the heat exchanging units is higher than that of the fixing unit. The fixing unit is configured to slow heat conduction between the heat exchanging units. The heat exchanging element improves a heat recovery efficiency of the fuel cell system. In addition, two kinds of fuel cell systems using the above-mentioned heat exchanging element are provided.

Abstract: An intake pipe for an internal combustion engine, comprising an outer housing of the intake pipe, wherein a feed line for charge air opens into an inlet section of the housing, a heat exchanger that is integrated in the intake pipe and cooled by a coolant and that comprises a plurality of exchanger tubes, in particular flat tubes, and an engine flange for connecting the intake tube to a cylinder head of an internal combustion engine, wherein charge air flows through the exchanger tubes and at least a section of the outer housing is designed as a water jacket surrounding the exchanger tubes.

Abstract: Disclosed are an instantaneous boiler and a double pipe heat exchanger for the instantaneous boiler supplying heating water and hot water, which can obtain hot water output larger than heating water output, simultaneously use the heating water and the hot water, and have a simple piping structure. The heat exchanger includes: an outer pipe used for a hot water pathway, to which combustion heat is directly transferred from a burner in a combustion chamber; and an inner pipe used for a heating water pathway and extending through the outer pipe.

Abstract: A heat exchanger for a vehicle may include a heat radiating portion provided with first and second connecting lines formed alternately by stacking plates, and receiving first and second operating fluids into the first and second connecting lines, a bifurcating portion connecting an inflow hole for flowing one operating fluid of the first and second operating fluids with an exhaust hole for exhausting the one operating fluid, and adapted for the one operating fluid to bypass the heat radiating portion according to a temperature of the one operating fluid, and a valve unit mounted corresponding to the inflow hole and adapted to flow the one operating fluid selectively to the heat radiating portion or the bifurcating portion according to the temperature of the one operating fluid flowing in the inflow hole.

Abstract: A cross-corrugated structure packing module is provided for use in mass transfer or heat exchange columns and has particular applicability in severe service applications in which fouling, coking, and erosion are of concern. The structured packing module has a plurality of upright, parallel-extending, corrugated plates. Spacer elements are used to maintain the corrugations of adjacent plates in spaced apart relationship to reduce the opportunity for solids to accumulate on the surfaces of the plates. The plates are also free of apertures or surface treatments that would increase the opportunity for solids to accumulate on the plates.

Abstract: An inclined waved board and a heat exchanger thereof. The inclined waved board includes a board body composed of continuous waved sections. The waved sections are respectively inclined from a first side to a second side, and a third side and from a fourth side to the second side of the board body. The waved sections define multiple raised sections and recessed sections on two faces of the board body. The heat exchanger is composed of multiple board bodies arranged adjacent to and in parallel to each other. Each two adjacent board bodies define therebetween a flow way. The inclined waved sections enhance turbulence intensity and guide the fluids to produce secondary flows along the cross-sections of the flow ways to form dynamic three-dimensional swirling flow structures which combine to augment heat transfer rates with reduced pressure-drop.

Abstract: A plate-type heat exchanger for use in a fuel cell system that has a fuel cell stack and a reformer is provided. The heat exchanger includes a substrate and a pair of cover plates. The substrate has a first face and a second face opposite to the first face. The substrate is disposed between the cover plates, and combined with the cover plates to form a first passageway and a second passageway. The first passageway is formed in the first face and circulates steam discharged from the fuel cell stack. The steam or water condensed from the steam is supplied to a water supply source. The second passageway is formed in the second face, and circulates water supplied from the water supply source. The water is supplied to the reformer after the circulation. The heat exchanger of the present invention improves performance and efficiency of a fuel cell system.

Abstract: A process for the generation of energy and/or hydrocarbons and other products utilizing carbonaceous materials. In a first process stage (P1) the carbonaceous materials are supplied and are pyrolysed, wherein pyrolysis coke (M21) and pyrolysis gas (M22) are formed. In a second process stage (P2), the pyrolysis coke (M21) from the first process stage (P1) is gasified, wherein synthesis gas (M24) is formed, and slag and other residues (M91, M92, M93, M94) are removed. In a third process stage (P3), the synthesis gas (M24) from the second process stage (P2) is converted into hydrocarbons and/or other solid, liquid, and/or gaseous products (M60), which are discharged. The three process stages (P1, P2, P3) form a closed cycle.

Abstract: Process for the production of ammonia from a hydrocarbon feedstock all steam produced in the waste heat boilers of the reforming and ammonia section of the plant is superheated in one or more steam superheaters located downstream the ammonia converter in the ammonia section of the plant. There is no need for steam superheater (s) in the reforming section of the plant to cool the synthesis gas. A steam superheater for use in the process is also provided. The superheater comprises two compartments in which the first and second compartments are connected in series with respect to the steam flow and in parallel with respect to the process gas flow.

Abstract: A gas turbine engine recuperator recuperator including exhaust passages providing fluid flow communication between an exhaust inlet and an exhaust outlet, the exhaust inlet being oriented to receive exhaust flow from a turbine of the engine and the exhaust outlet being oriented to deliver the exhaust flow to atmosphere, the exhaust passages having an arcuate profile in a plane perpendicular to a central axis of the recuperator to reduce a swirl of the exhaust flow. Air passages are in heat exchange relationship with the exhaust passages and providing fluid flow communication between an air inlet and an air outlet, design to sealingly respective plenum of the gas turbine engine.

Abstract: A coil on tube heat exchanger is provided that uses multiple parallel helical coil tubes to limit liquid pressure losses while providing similar performance and production times to previous coil and tube designs. Two or more coil tubes are wrapped together around a center tube in a helical fashion, permitting the heat exchanger to be used in a counter-flow, or contra-flow, implementation. Use of the heat exchanger includes flowing a first liquid, such as waste water, through the center tube and flowing a second liquid through the plurality of channels. Embodiments of the present invention provide reduced pressure loss, higher performance and are generally faster to manufacture than prior heat exchangers.

Abstract: Heat transmission units are known wherein ribs for improving the cooling efficiency extend along the whole length of the flow path of the radiator. According to the invention, it is proposed, while keeping the constructional space at the same size, to provide a larger cooling surface in a first portion, which has a higher temperature gradient, and which is accomplished by a large number of ribs arranged therein, and to omit such ribs or to reduce their number in a region that has a lower temperature gradient, i.e. in a second portion. In this manner, the overall efficiency of such a heat transmission unit is improved.

Abstract: The present invention relates to a heat exchanger (1) comprising a first flow passage (6) comprising a tubular element (2) comprising at least two tubular flow channels (4) separated by region (5) extending along a longitudinal Y-axis, for passage of a first medium, and a second flow passage (8) for passage of a second medium between tubular element and a heat transfer element (3). The tubular element comprises a first surface (A) comprising at least region and two bulging sections (7). The heat transfer element comprises a second surface (B) comprising at least region 5? and two indentation, cavity or nest sections (17). The first surface and the second surface are adapted to contact each other and have a complementary shape such that the bulging sections of the first surface are in continuous contact with the indentation, cavity or nest sections of the second surface.

Abstract: Various hot box fuel cell system components are provided, such as heat exchangers, steam generator and other components.

Abstract: A cooling module and a water-cooled motor system using the same are provided. The cooling module comprises a main body and a first flow passage assembly. The main body comprises a first lateral portion and a second lateral portion opposite the first lateral portion. The first flow passage assembly, disposed in the main body, comprises a first flow passage and a second flow passage. The first flow passage has a first end and a second end, wherein the first end is adjacent to the first lateral portion, and the second end is adjacent to the second lateral portion. The second flow passage has a third end and a fourth end, wherein the third end is connected to the second end of the first flow passage, and the fourth end is adjacent to the first lateral portion.

Abstract: A feed gas conditioner.

Abstract: An elongated structure (100) for the transmission of fluid-based compositions at non-ambient temperatures comprising a first conduit (130) for the transmission of a fluid-based composition, at least one flexible, elongated and inflatable temperature control conduit (110a, 110b) for the transmission of a temperature control fluid, the temperature control conduit (110a, 110b) having a relatively rigid elongated reinforcement member (116a, 116b); and elongated cover (140) holding said temperature control conduit (100a, 110b) in thermal communication with the first conduit (130).

Abstract: The embodiments of the present invention provide an insert box with front and rear insertion and a heat dissipation method of the insert box. The insert box includes a front board area, a backboard, and a rear board area. A first air flow passing from a first wind inlet at an upper end portion at a front side of the insert box passes through one of the front board area and the rear board area; and a second air flow passing from a second wind inlet at a lower end portion at the front side of the insert box passes through the other one of the front board area and the rear board area.

Abstract: A vaporizing heat exchanger (10, 68) is provided for vaporizing a fluid flow using a thermal energy containing flow. Flow paths (24, 26, 28) for each of the fluid flow and the thermal energy containing flow are located relative to each other such that the fluid flow makes multiple passes wherein the fluid is vaporized and subsequently superheated.

Abstract: To provide a ceramic heat exchanger which has reduced joints, and thus, is easy to produce and less likely to leak and a method of producing same. The ceramic heat exchanger 1 according to the present invention comprises a body 2 having first channels 21 for a high-temperature medium to flow and second channels 22 for a low-temperature medium to flow, and lids 3 each having openings 31, joined to the body 2 at opposite ends 2a, 2b with the openings 31 connected to the first channels 21, the body 2 further having inlet channels 23 formed in a first channel 21 outlet-side end portion 2a to allow the low-temperature medium to enter the body at a side thereof and flow into the second channels 22, and outlet channels 24 formed in a first channel 21 inlet-side end portion 2b to allow the low-temperature medium to flow out of the second channels 22 and leave the body at the side thereof.

Abstract: The conducting type inter-piping fluid thermal energy transfer device has a thermal conducting structure installed between a thermal conductive casing of a first piping where the first piping has at least one fluid inlet and at least one fluid outlet for passing through a supply of water flow, and a thermal conductive casing of a second piping having at least one fluid inlet and one fluid outlet for passing through thermal conducting fluid.

Abstract: Disclosed is a double pipe heat exchanger for a boiler supplying heating water and hot water, which can prevent water from being condensed even if cold heating water or cold water is introduced into an inlet of the heat exchanger in the boiler for supplying heating water and hot water The heat exchanger includes: a plurality of outer heating water pipes to which combustion heat is applied from a burner of a combustion chamber; a plurality of inner pipes, each of which is inserted in each outer pipe; a returned heating water pipe in which cold heating water is introduced; and a cold water pipe in which cold water is introduced, wherein the returned heating water pipe and the cold water pipe are connected to one of the inner pipes.

Abstract: A heat exchanger is provided for a motor vehicle air-conditioning system with an outer tube through which a fluid and/or a gas can flow and at least one inner tube through which a fluid and/or gas can flow, which at least in sections and subject to the formation of an intermediate space through which a flow can flow runs within the outer tube and in a first region located within the outer tube branches off into at least two heat exchanger tubes.

Abstract: New designs, methods and processes are described that in which laminated devices and configured in a style named the “ortho” style. To form a device in the ortho style, plates or sheets are machined to have apertures and then stacked together such that the apertures connect and fluid can flow through the device in a direction that is substantially parallel to the direction of sheet thickness. Various laminated devices and processes using them are also described. For example, devices in which non-rectangular microchannels conform around reaction chambers or other bodies that need to be heated or cooled, are described. Features that separate or trip boundary layer and enhance heat transfer are also described.

Abstract: Disclosed is a heat exchanger of a plate type comprising an evaporator having at least one inlet and at least one outlet allowing a first medium to enter into and exit from the evaporator. The evaporator comprises a plurality of interconnected evaporation chambers disposed in parallel, having at least one common inlet and at least one common outlet allowing the first medium to enter into and exit from the evaporation chambers.

Abstract: A distiller's counterflow-heat-exchanger module includes thermally conductive distillate and concentrate dividers across which heat flows to an influent liquid from distillate and concentrate liquids, respectively. The distillate divider's shape is convoluted in such a manner as to form alternating distillate and influent channels having end openings. A peripheral gasket is so over-molded onto the distillate divider that it forms plugs that seal the end openings from each other and further forms a ridge providing surfaces against which opposed generally planar parallel surfaces of cover members can be urged to form a peripheral seal.

Abstract: An architectural heat and moisture exchanger. The exchanger defines an interior channel which is divided into a plurality of sub-channels by a membrane configured to allow passage of water vapor and to prevent substantial passage of air. In some embodiments, the exchanger includes an opaque housing configured to form a portion of a building enclosure, such as an exterior wall, an interior wall, a roof, a floor, or a foundation.

Abstract: A cylindrical, annular axial flow heat exchanger for use as a gas cooler in a thermal regenerative machine such as a Stirling engine is provided. The heat exchanger includes an outer shell of sufficient strength and thickness to withstand the pressure exerted by the working fluid and a tubular member positioned adjacent to and in contact with the outer shell, the tubular member having spaced apart sidewalls defining a flow passage therebetween. At least one of the sidewalls of the tubular member is embossed with ribs, the ribs being in contact with the inner surface of the outer shell thereby defining axially extending flow passages between the outer shell and tubular member along the circumference thereof for the flow of a second, gaseous fluid through the heat exchanger. The first fluid flows circumferentially through tubular member, while the second fluid flows axially between the outer shell and the tubular member.

Abstract: A counterflow heat exchanger having a plurality of heat exchanger elements in a stacked, spaced-apart arrangement forming a plurality of inter-element passages. Each element has fluid passages formed between facing sections of a first plate and a second plate. A first-fluid passage has an outer passage circumscribing an inner passage in fluid communication with the outer passage. An inlet-port traversing passage in fluid communication with the outer passage, an outlet-port traversing passage in fluid communication with the inner passage and a second-fluid traversing passage circumscribed by the inner passage traverse the first and second plates. A first-fluid inlet header includes the inlet-port traversing passage of each element. A first-fluid outlet header includes the outlet-port traversing passage of each element. A second-fluid inlet passage in fluid communication with the plurality of inter-element passages includes the second-fluid traversing passage of each element.

Abstract: The present invention relates to a heat-exchanger reactor comprising a vessel, at least one dividing member selected from plates, walls, or spiral sheets, which dividing member separates heat exchanging fluids into at least one heat exchanging zone from fluids into at least one mixing zone, and at least one flow-directing device having one or more ports or one or more injection ports, which flow-directing device is inserted into the mixing zone. The present invention relates also to uses of the heat-exchanger reactor.

Abstract: The present disclosure teaches apparatuses, systems, and methods for improving energy efficiency using high heat capacity materials. Some embodiments include a phase change material (PCMs). Particularly, the systems may include a re-gasification system, a liquefaction system, or an integrated system utilizing a heat exchanger with a regenerator matrix, a shell and tube arrangement, or cross-flow channels (e.g. a plate-fin arrangement) to store cold energy from a liquefied gas in a re-gasification system at a first location for use in a liquefaction process at a second location. The regenerator matrix may include a plurality of PCMs stacked sequentially or may include a continuous phase material comprised of multiple PCMs. Various encapsulation approaches may be utilized. Reliquefaction may be accomplished with such a system.

Abstract: A heat transfer unit for an internal combustion engine includes a first channel with an inlet and an outlet. The first channel is configured to have a fluid to be cooled flow therethrough. The second channel is configured to have a cooling fluid flow therethrough. A partition wall(s) is disposed to separate the first channel from the second channel. Ribs extend from partition wall(s) into the second channel and are disposed in a principal flow direction of the fluid to be cooled. The second channel comprises a first section and a second section in the principal flow direction. The ribs of the first section have a first cross section in a first flow-off portion that is constant in the principal flow direction. The ribs of the second section have a second cross section in a second flow-off portion that widens in the principal flow direction.

Abstract: A heat exchanger includes a heat transfer tube group in which a plurality of first heat transfer tubes (3) through which a first fluid flows and a plurality of second heat transfer tubes (4) through which a second fluid that exchanges heat with the first fluid flows are arranged alternately while being in contact with each other. The heat transfer tube group is formed in a spiral shape by being wound in X direction perpendicular to Y direction in which the first heat transfer tubes (3) and the second heat transfer tubes (4) are arranged. A plurality of concave portions (3a) are provided on both sides, in the X direction, of an outer circumferential surface (31) of each of the first heat transfer tubes (3), along an extending direction of the first heat transfer tube (3). The plurality of concave portions (3a) form convex portions on an inner circumferential surface of the first heat transfer tube (3).

Abstract: A process for exchanging heat in a shell and tube gas-to-gas heat exchanger between a plurality of gases, said process comprising passing a cold first gas in parallel flow to a second hot gas to provide a warmer first gas; and passing said warmer first gas in counter-current flow to a hot third gas to provide a cooler said third gas. The invention provides increased minimum tube wall temperature within the exchanger for given process conditions while maintaining a high log mean temperature differential allowing for the prevention of corrosion from entrained corrosive vapours or entrained corrosive mist with a minimal increase in effective area.