Abstract: A heat exchanger (4) comprises a heat exchanger core (20) comprising first fluid channels (22) and second fluid flow channels (24) for exchange of heat between the first and second fluids. First and second manifold portions (42, 44) are provided to guide the first and second fluids between the first and second fluid flow channels (22, 249 and first and second fluid interface portions (48, 49) which comprise fewer channels than the heat exchanger core (20). The first manifold portion (42) includes at least one tunnel portion (46) extending through the second manifold portion (44) at an angle to the direction of second fluid flow. Hence at least part of the first fluid is directed through the inside of the tunnel portion while the second fluid passes around the outside of the tunnel portion. This enables more compact heat exchanger design.

Abstract: A plate heat exchanger includes a first plate sheet and a second plate sheet. A blocking member is disposed between a front surface of the second plate sheet and a back surface of the first plate sheet. The blocking member is located between a first corner hole and a second corner hole of the second plate sheet, and one end of the blocking member is located on a side portion of the second plate sheet. A first corner hole of the second plate sheet bypasses the other end of the blocking member to communicate with a second corner hole of the second plate sheet. In the plate heat exchanger, a blocking member is disposed between two plate sheets, accordingly fluid can be evenly distributed, and the plate heat exchanger has good heat exchange performance.

Abstract: A tank for a radiator. The tank includes an inlet port through which coolant enters the tank. A wall at least partially defines a cavity in fluid communication with the inlet port. A curved surface of the wall is opposite to the inlet port and reduces volume of the cavity at the inlet port. The curved surface is configured to reduce turbulence of coolant flowing into the cavity from the inlet port. At least one turning vane extends along the wall into the cavity from the inlet port. The at least one turning vane is curved to reduce turbulence of coolant flowing through the inlet port and into the cavity.

Abstract: A heat exchanger includes a plate-shaped fin elongated in a longitudinal direction, a plurality of heat transfer tubes passing through the fin, and a distributor that distributes refrigerant to, from among the plurality of heat transfer tubes, two heat transfer tubes. The distributor includes an inflow portion being linear and connected to one of the plurality of heat transfer tubes, a turn-back portion continuous with the inflow portion, a first outflow portion being linear, continuous with the turn-back portion and running in parallel to the inflow portion, a second outflow portion being linear, continuous with the turn-back portion and branching from the first outflow portion, and a connection pipe continuous with the second outflow portion and including a plurality of bent portions. The second outflow portion is connected via the connection pipe to the heat transfer tube not adjacent to the heat transfer tube connected to the first outflow portion.

Abstract: A U-tube heat exchanger wherein a tube support plate divides the interior of a tube-exterior fluid chamber into a curved-tube chamber on a second end side including curved-tube sections of the U-tubes, and a chamber on a first end side. A second partition wall divides the interior of the chamber on the first end side inside the tube-exterior fluid chamber into a first straight-tube chamber including inlet-side straight-tube sections of the U-tubes, and a second straight-tube chamber including outlet-side straight-tube sections of the U-tubes. An opening penetrating from the first straight-tube chamber into the second straight-tube chamber is formed in the second partition wall. First passage holes, which penetrate from the first straight-tube chamber into the curved-tube chamber, and second passage holes, which penetrate from the second straight-tube chamber into the curved-tube chamber, are formed in the tube support plate.

Abstract: A substrate placing table, which is installed inside a processing container for processing a wafer, includes: a stage configured to place a water on an upper surface thereof and including an inner peripheral flow channel and an outer peripheral flow channel formed therein to circulate a heat medium of a predetermined temperature therethrough; a support table configured to support the stage; and a temperature adjusting plate installed between the stage and the support table, and including a temperature adjusting mechanism configured to adjust a temperature of a heat radiation portion at which heat is radiated between the stage and the support table.

Abstract: By stacking a plurality of core plates (15) each of which has, around a peripheral edge of a base portion (30), an outer peripheral tapered portion (31) that expands outward, and joining the outer peripheral tapered portions (31) of adjacent core plates by brazing, a heat exchanging fluid passage (17, 18) is defined between the base portions (30) of the adjacent core plates. Outer and inner peripheral surfaces of the outer peripheral tapered portion are shaped to extend straightly in cross section. A leading end part of the outer peripheral tapered portion (31) is formed at the inner peripheral surface thereof with a recess (33) that is depressed toward the outer peripheral surface.

Abstract: A heat exchanger for heat exchange between at least two fluids, in particular for a motor vehicle, includes: a core (3) for heat exchange between the fluids, and a casing (5) for receiving the core and having at least one side opening. The exchanger further includes a cover (7) for closing the at least one opening in the casing (5), which is tightly connected to the core (3) and the casing (5) in order to form a non-separable unit assembly.

Abstract: A heat exchanger for heat exchange between at least two fluids, especially for a motor vehicle, comprises a bundle (7) for heat exchange between said fluids, and a housing (9) for receiving said bundle (7), said housing (9) having at least one raised edge (11). The heat exchanger also has a seal (15) of a rigid plastic material, said seal enveloping said at least one raised edge (11) and being designed to ensure the tightness between the exchanger and a container of said exchanger. The heat exchanger can also be included in an air intake device including such a heat exchanger and an air intake collector.

Abstract: An aircraft system is provided that includes a fuel reservoir, a turbine engine and a fuel-to-fuel heat exchanger. The heat exchanger is fluidly coupled between the fuel reservoir and the turbine engine.

Abstract: A heat exchanger includes a plurality of refrigerant tubes. In a flow divider, a part of a plurality of capillary tubes is connected to an open end portion on a side of a front tube plate, and a remainder of the plurality of the capillary tubes is connected to an open end portion on a side of a rear tube plate. The plurality of refrigerant tubes include even number refrigerant tubes constituted by an even number of heat transfer tube portions and odd number refrigerant tubes constituted by an odd number of heat transfer tube portions.

Abstract: A device for cooling a heat source of a motor vehicle is provided that includes a cooling body which has a plurality of feed flow channels and a plurality of return flow channels. At least a multiplicity of the feed flow channels and return flow channels are arranged adjacent to one another in an alternating fashion in the cooling body.

Abstract: A vehicle air conditioner is disclosed having means to cool and heat air with three air paths, of which, two outer air paths have a common first temperature and an inner air path has a second temperature, wherein a means for controlling the air volume flow through the outer air paths and the inner air path is provided by two control elements which are configured jointly to be able to move in opposing directions.

Abstract: Ventilated heat shields and methods are disclosed. The ventilated heat shield can use varying patterns of insulating material with ventilation regions arranged in one or more two-dimensional (2D) and/or three-dimensional (3D) patterns to provide thermal insulation and air channels that allow for dissipation of heat and the inflow of cooling air. The ventilated heat shield can be used in applications where two surfaces are required to be in very close proximity or contact with each other to reduce the transfer of heat from one surface to the other. An example application for the ventilated heat shield is in a vehicle braking system.

Abstract: An air duct is made to be set on a motherboard in a variety of different locations and aspects, for covering a number of electronic components in the most efficient way. The air duct includes a top wall, two sidewalls extending down from opposite sides of the top wall, and a frame mounted to a first end of the top wall. The frame defines a receiving space for receiving a fan, the manner of installation of the air duct permits more than one installation location, to allow for new or differently-located components on the motherboard.

Abstract: A heat exchanger includes a heat exchanging section for performing heat exchange between a refrigerant and a cooling medium and a passage section. The passage section includes a first passage and a second passage for supplying the refrigerant to the heat exchanging section and a supply passage for supplying the refrigerant to the first passage and the second passage. The first passage and the second passage define a first opening portion and a second opening portion opening at an end of the supply passage. A minimum distance between an opening edge of the first opening portion and an inner surface of the supply passage is equal to a minimum distance between an opening edge of the second opening portion and the inner surface of the supply passage.

Abstract: A heat exchanger is described comprising a distributor having an outer housing and including a plurality of substantially parallel plates disposed within the housing and configured to partition an input two-phase flow into a series of primarily single-phase layers. A heat exchanger is described comprising a distributor having an outer housing including a plurality of substantially parallel channels disposed therein, each channel configured to uniformly and independently convey a portion of a homogenous input two-phase flow from an input of the distributor to an output of the distributor.

Abstract: A cooler arrangement comprising a charge air cooler which comprises at least one first pipeline for guiding compressed air during cooling and a tank which receives the cooled compressed air via an outlet aperture from the first pipeline, and an EGR cooler which comprises at least one second pipeline for guiding exhaust gases during cooling and a tank which receives the cooled exhaust gases from an outlet aperture of the second pipeline. The cooler arrangement comprises a tubular element extending from the EGR cooler's tank to the charge air cooler's tank. The tubular element has an outlet aperture for exhaust gases which is situated downstream of the most downstream outlet aperture in the charge air cooler's tank with respect to the main direction of flow of the air in the tank.

Abstract: A modified atmosphere package for extending the shelf life of a replaceable transducer cartridge having a sealed volume and containing a fluid. The fluid may be fluid or a gas. If a fluid, such as water, then the modified atmosphere package may be configured to prevent the loss of fluid or the entry of gas into the transducer cartridge.

Abstract: The present invention relates to a system of creating and applying a heated cleaning fluid to a surface. The system includes a housing with a first, a second and a third exhaust gas opening. A first, second, and third heat exchanger are enclosed within the housing. The first and second exchangers are serially arranged, while the third is at an angle relative to the first and second and directly adjacent to the first opening. Super heated exhaust gas flows through first opening and third exchanger. Heated gas flows through the second opening and passes below the third exchanger. Super heated exhaust gas exiting the third exchanger mixes with the heated gas in a mixing chamber of the housing, which is then supplied to the first and second exchangers. Fluid passes through the three exchangers and exits the third exchanger heated. That heated fluid passes to a cleaning wand for application.

Abstract: An air conditioner is disclosed which includes a case including an external air inlet opening formed in a side of the case, a heat exchanger provided in the case, and a guide part which guides external air which enters the case through the external air inlet opening into an interior of the heat exchanger.

Abstract: An improved precision cooling system for high heat density applications comprises a heat exchanger having more fluid outlet conduits than fluid inlet conduits to optimize the pressure drop across the heat exchanger at a given fluid flow rate. The heat exchanger may be of microchannel or tube fin construction, and the cooling system may utilize single phase or multi-phase pumped or compressed fluids.

Abstract: A phased array antenna apparatus has a plurality of circuit portions which are each coupled to a respective antenna element. Capillary pressure of a cooling fluid within a wick in a loop is utilized to urge the fluid to travel around the loop, the wick being disposed in the region of the circuitry. In a variation, there are plural wicks in respective evaporators, and cooling fluid is distributed among the evaporators through a series of T-junctions. In another variation, cooling fluid is distributed to a plurality of evaporators in a sequence corresponding to a progressive increase in the respective amounts of heat accepted by the evaporators from structure being cooled.

Abstract: A gas preheater (10) that includes an exit plate (20) having first and second sides (22, 24) and a plurality of through holes (26) and at least one body (34) mounted adjacent the first side (22), the at least one body (34) having a first end (36) and a second end (38), the second end (38) located between the body first end (36) and the exit plate first side (22), at least one sidewall (40) connecting the first and second ends (36, 38), a body opening (42) in the first end (36) extending into the body (34) and defining a body inner wall (44), and a plurality of passages (46) extending between the at least one sidewall (40) and the body inner wall (44).

Abstract: A gas preheater (10) includes an entrance plate (12) having a first side (14), a second side (16), at least one opening (18) connecting the first side (14) and the second side (16), and a plurality of walls (19) on the second side (16) having tops (21) spaced from the second side (16), the walls (19) defining at least one circuitous pathway (22e, 22f, 22g, 22h) on the second side (16) beginning at the at least one opening (18), and a diffuser plate (40) having a first side and a second side and a plurality of holes (42) between the first side and the second side, the diffuser plate first side defining with the entrance plate second side (16) and the plurality of walls (19) at least one circuitous passage along the at least one circuitous pathway (22e, 22f, 22g, 22h), the at least one circuitous pathway having a first portion (22e1) leading from the at least one opening (18) and a second portion (22e2) spaced from the at least one opening (18), wherein the holes (42) in the diffuser plate (40) overlie the circ

Abstract: The invention relates to a method for the gasification of carbonaceous materials in the form of solid particles. The inventive method comprises the following steps consisting in: heating a gaseous mixture formed by a feed gas and water vapor in a heater (1); bringing the particles of the carbonaceous materials into contact with the heated gaseous mixture in a pressurized gasification reactor (2), with the formation of a raw reaction gas and unburnt ash; separately supplying the heater with (i) water vapour and (ii) the aforementioned feed gas; taking separate samples from the heater of the gaseous mixture (at point 13) and of part of the feed gas in the dry state (at point 16); and injecting into the gasification reactor said dry feed gas and a gas forming therewith a fuel mixture in the ash.

Abstract: A system and method is provided for an electrical component enclosure that controls the temperature of the coolant in the internal coolant loop through the enclosure to prevent the formation of condensation on the coolant tubes. Warm coolant is diverted from a heat exchanger to a mixing valve where it is mixed with chilled coolant before entering the enclosure. Humidity and temperature levels are monitored within the enclosure and processed by a microprocessor to determine the temperature of the coolant needed in the tubes.

Abstract: An improved precision cooling system for high heat density applications comprises a heat exchanger having more fluid outlet conduits than fluid inlet conduits to optimize the pressure drop across the heat exchanger at a given fluid flow rate. The heat exchanger may be of microchannel or tube fin construction, and the cooling system may utilize single phase or multi-phase pumped or compressed fluids.

Abstract: A vertical heat exchanger is described, which allows efficient elimination of the gas generated therein and efficient removal of the sludge accumulated therein. The vertical heat exchanger has at least part of one end of a vent pipe formed of an upper tube sheet part (an upper cover part in the case of a spiral heat exchanger) and the other end thereof connected outside the heat exchanger to an immediately adjacent fluid passing port passing the same fluid as the vent and/or at least part of one end of a drain pipe formed of a lower tube sheet part (a lower cover part in the case of a spiral heat exchanger) and the other end thereof connected outside the heat exchanger to an immediately adjacent fluid passing port passing the same fluid as the drain.

Abstract: The present invention provides a header of a heat exchanger. The header can include a tank having a tank outlet, and an integral fitting including a body extending outwardly away from the tank outlet and having an outlet located remotely from the tank outlet, an inlet located between the tank outlet and the fitting outlet, and a baffle located within the body adjacent to the inlet to direct at least a portion of a fluid flow from the inlet toward the fitting outlet.

Abstract: The subject invention provides a heat sink for cooling electronic devices. The heat sink includes an upper chamber and a lower chamber separated by a baffle therebetween. The lower chamber includes a base having a central axis and a plurality of curvilinear fins disposed radially about the central axis of the base. The upper chamber includes a lid defining an inlet and an inlet tube interconnecting the upper chamber and the lower chamber for directing a fluid through the upper chamber and impinging the fluid on the base in the lower chamber. A sidewall extends between the base and the lid and is disposed about the fins. The sidewall includes a peripheral inlet for directing the fluid perpendicular to the central axis and at the fins.

Abstract: A phased array antenna apparatus has a plurality of circuit portions which are each coupled to a respective antenna element. Capillary pressure of a cooling fluid within a wick in a loop is utilized to urge the fluid to travel around the loop, the wick being disposed in the region of the circuitry. In a variation, there are plural wicks in respective evaporators, and cooling fluid is distributed among the evaporators through a series of T-junctions. In another variation, cooling fluid is distributed to a plurality of evaporators in a sequence corresponding to a progressive increase in the respective amounts of heat accepted by the evaporators from structure being cooled.

Abstract: In a charge-air cooling circuit for a multicylinder internal-combustion engine 1 with a turbo-supercharger 2, downstream from the turbo-supercharger 2 the charge air fed to two separate charge-air coolers 6, 6?, whereby the first charge-air cooler 6 divides the charge air into two flow branches I, II, cools the first of the two flow branches I, and allows the second of the two flow branches II to pass uncooled, and whereby the second charge-air cooler 6? allows the first of the two flow-branches I to pass uncooled, cools the second of the two flow branches II, and then recombines the two flow branches I, II.

Abstract: A microfluidic device is provided for regulating the temperature of a sample fluid flowing therethrough, as well as, a method of regulating the temperature of the sample fluid flowing through the microfluidic device. The microfluidic device includes a body member defining a fluid channel for allowing the sample fluid to flow therethrough and a first regulating channel. A regulating fluid having a predetermined temperature flows through the regulating channel adjacent the fluid channel so as to effectuate a heat exchange with the sample fluid flowing through the fluid channel to regulate the temperature thereof.

Abstract: A phased array antenna apparatus has a plurality of circuit portions which are each coupled to a respective antenna element. Capillary pressure of a cooling fluid within a wick in a loop is utilized to urge the fluid to travel around the loop, the wick being disposed in the region of the circuitry. In a variation, there are plural wicks in respective evaporators, and cooling fluid is distributed among the evaporators through a series of T-junctions. In another variation, cooling fluid is distributed to a plurality of evaporators in a sequence corresponding to a progressive increase in the respective amounts of heat accepted by the evaporators from structure being cooled.

Abstract: The present invention relates to a cooling element of an electronic device, comprising: an inlet opening, and outlet opening, and a flow channel. To achieve efficient cooling with as low costs as possible, the flow channel is designed to cause a pressure difference between the forward end and tail end of the flow channel. At the higher-pressure forward end, an inlet opening is arranged for a secondary cycle. At the lower-pressure tail end of the cooling element flow channel, an outlet opening is arranged for said secondary cycle.

Abstract: A heat exchange system is provided in which low temperature water from a supply pump (15) is split and supplied to an auxiliary evaporator (17) provided so as to cover an exhaust port (16) extending from a combustion chamber of an internal combustion chamber (E) and to a main evaporator (11) provided downstream of the exhaust port (16). The direction of water flowing through the auxiliary evaporator (17) is parallel to the direction of flow of exhaust gas, and as a result an upstream section of the exhaust port (16), which has a high temperature, can be cooled effectively with low temperature water, and the escape of heat from the upstream section of the exhaust port (16) can be suppressed.

Abstract: An exhaust gas cooler for an internal combustion engine, preferably in a motor vehicle, includes a housing through which exhaust gas can flow in the longitudinal direction and in which a partition extends in the longitudinal direction and separates a first chamber from a second chamber. An inlet communicates in the housing with a first chamber and through which the exhaust gas flows into the housing. An outlet communicates in the housing at least with the second chamber and via which the exhaust gas flows out of the housing. The partition has at least one overflow opening through which the first chamber communicates with the second chamber.

Abstract: An apparatus and method for producing liquefied natural gas. A liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream passes through a turbo expander creating work output. A compressor is driven by the work output and compresses the process stream. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is divided into first and second portions with the first portion being expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. The second portion of the cooled, compressed process stream is also expanded and used to cool the compressed process stream. Additional features and techniques may be integrated with the liquefaction process including a water clean-up cycle and a carbon dioxide (CO2) clean-up cycle.

Abstract: A heat transfer plate for a plate heat exchanger has a heat transfer portion (210) having elevations and depressions (30; 130; 230), a first port portion (G), a second port portion (H), first sealing portions (214, 215a-d), and second sealing portions (244, 216, 217). The plate has a symmetry line (S), which extends from a first edge (202) to a second edge (203) of the plate and in relation to which the plate's heat transfer portion, sealing portions and ports to be passed by each of the heat transfer fluids are symmetrically arranged. The elevations and depressions (230), are located in such manner relative to the symmetry line (S) that when two identical plates are brought to abut against each other—one of the plates being rotated through 180 degrees about the symmetry line (S)—the elevations (230) on the plates will form distance means between the plates in a large number of positions distributed over the heat transfer portions (210) of the plates.

Abstract: A plate pack for a plate heat exchanger comprises a number of heat transfer plates (100) having a number of through ports (110a-d, 120a-f), said plates (100) interacting in such manner, that the plates (100) between them form a first flow duct and a second flow duct and that the ports (110a-d, 120a-f) form at least one inlet duct and at least one outlet duct (110a-d, 120a-f; 230, 240; 330, 340; 630, 640) for each of the flow ducts. The inlet duct of at least the first flow duct comprises at least two primary ducts (110a-b; 230a-b; 330a-b; 630a-b), which are arranged to receive a fluid flow intended for the first flow duct, and at least one secondary duct (110c), which communicates via a flow passage with the primary ducts (110a-b) and the first flow duct and which is arranged to receive said fluid flow from the primary ducts (110a-b) and to convey this flow to the first flow duct.

Abstract: Thermal management devices and methods include branching networks comprising flow channels of varying cross-sectional area. The branching networks can be fractal-like in nature with an increase in the total flow area following a flow channel bifurcation. In representative embodiments, the branching networks are defined in a channel pattern that is laminated between cover plates to form a thermal management device. The channel pattern includes bridging portions so that the branching network is defined with a single pattern piece. The branching networks can exhibit radial symmetry or be aligned with respect to one or more axes. Heat exchangers and diffusive mixers that include such networks are also provided.

Abstract: A vapor compression system including a compressor, a condenser, an expansion device, and an evaporator. The evaporator includes a main distributor having an inlet, a first outlet, and a second outlet, a coil, the coil having an inlet connected with the first outlet of the main distributor, an outlet, and at least one opening, wherein the opening is located on a surface of the coil between the inlet and the outlet, and a feed line connecting the second outlet of the main distributor to the coil opening. The vapor compression system includes a discharge line connecting the compressor to the condenser, a liquid line connecting the condenser to the inlet of the expansion device, a saturated vapor line connecting the outlet of the expansion device to the inlet of the main distributor, and a suction line connecting the outlet of the coil to the compressor.

Abstract: Plate heat exchanger has heat transfer plates which exhibit a patterning and are stacked one above the other. Primary sided flow channels for a first heat exchanger medium to be evaporated, and secondary sided channels for a second heat exchanger heat carrier medium are formed between the plates. The primary sided and/or the secondary sided flow channels are formed between two adjacent heat transfer plates, whose patterning meshes at least partially, while maintaining a minimum spacing.

Abstract: A heat exchanger comprising: a plurality of longitudinally extending tubes grouped into at least first, second and third passes; the tubes in the first pass being serially connected with tubes in the second pass; the tubes in the second pass being serially connected with tubes in the third pass; and wherein the number of tubes in the first pass is greater than the number of tubes in the third pass.

Abstract: An apparatus for controlling temperature and humidity of a conditioned space uses an outside air cooling coil circuit in fluid communication with coolant from a cooling supply. Outside air is introduced over the outside air cooling coil circuit through a damper having open and closed positions. A valve in fluid communication with the coolant supply and the outside air cooling coil circuit has an open setting for permitting and a closed setting for preventing the circulation of coolant through the outside air cooling coil circuit. An HVAC unit control is operatively associated with the valve and the damper for controlling their operation. An occupancy control generates a signal indicating the presence of a human within the conditioned space and is operatively associated with the HVAC unit control.

Abstract: A two pass heat exchanger is provided. The first pass includes a plurality of tubes located in liquid refrigerant, when employed as an evaporator, whereby the liquid refrigerant draws heat from the water flowing through the tubes causing the water to be cooled and the liquid refrigerant to evaporate. The second pass is a single pipe which need not be located in the liquid refrigerant. The two pass heat exchanger can also be used as a condenser.

Abstract: A finned heat exchanger includes a plurality of elongated fins which are arranged at a predetermined interval in parallel with one another such that air flows between neighboring ones of the fins in a predetermined direction. A plurality of heat transfer tubes which contain refrigerant passing therethrough are orthogonally inserted through the fins so as to be arranged in a plurality of columns on the fins. When the finned heat exchanger is operated for condensation, the heat transfer tubes are provided in two paths in the vicinity of an inlet for the refrigerant and are provided in one path in the vicinity of an outlet for the refrigerant, such that the heat transfer tubes of the one path occupy about 5 to 30% of all the heat transfer tubes.

Abstract: A heat exchanger for a water-cooled internal combustion engine having a lubricant cooling system and an exhaust gas recirculation system includes a housing with cooling water inlet and outlet stubs by way of which cooling water is conducted through the interior of the housing, and a lubricant cooler is formed in the housing and separated from the cooling water space by a zigzag-shaped intermediate wall and a recirculated exhaust gas cooler is disposed in the housing in heat exchange relation with the cooling water flowing through the housing.

Abstract: Method and apparatus for moving a conditioning fluid, e.g. defrost gas, through a plate fin type heat exchanger having open-ended passages containing easyway or hardway finning. Each group of open-ended passages is provided with means to introduce the fluid into the passages at a location to achieve maximum contact of the fluid with each open-ended passage. A downflow reboiler according to the invention can be readily conditioned (e.g. defrosted).