Abstract: Waste water heat transfer apparatus (10) is disclosed in which the waste hot water from residential or commercial uses such as washing, etc., is passed into a separate drain (24) and then into a heat exchanger (17) which includes a waste water conduit (40) therein, and then to the sewer drain (29). A supply water conduit (70) extends through the heat exchanger (11) generally paralleling the waste water conduit (40) and has fresh water run therethrough in a direction opposite to that of the flow of waste water to an outlet end, after which the supply water is provided to a water heater (20). The heat exchanger interior is filled with a heat transfer liquid (39), and is so divided by baffles (75, 76) that a temperature gradient is formed in the heat transfer liquid adjacent to the waste water conduit (40), with the liquid being warmest adjacent the inlet (68) of the waste water conduit and decreasing in temperature toward the outlet (69) of the conduit.

Abstract: Steam generator of the sodium-water type comprising a primary circuit constituted by an elongated vessel filled with liquid sodium, an inlet zone of the elongated vessel into which the liquid sodium is introduced, an outlet zone of the elongated vessel from which the liquid sodium is removed, and a secondary circuit constituted by a plurality of water circulation tubes extending to the inside of the elongated vessel. Inside the elongated vessel is arranged a tank open only downwards, immersed in the sodium contained in the vessel, and at least partly filled with an inert gas, so as to constitute in the vessel, at the level of the outlet zone of the sodium, an expansion tank for limiting the propagation of a pressure wave resulting from chemical reaction between the sodium and the water. The generator is particularly useful in nuclear power stations.

Abstract: This invention relates to method and apparatus used as an addition to any existing heating system--burning any fuel--for heat recovery from stacks and chimneys. It uses a suitable heat exchanger mounted at the apex of such stacks, by virtue of which location no natural draft is lost. The system includes a circulating pump, a thermostat, an expansion bottle, a condensate trough, a cap and dome which jointly serve to act as unloaders to protect the system liquid from being boiled off. Both sensible heat and the latent heats of moisture in the fuel and in the vapor produced as a combustion product, can be scrubbed out. The use is to effect economies and to reduce environmental contamination wherever fuels are fired.

Abstract: The specification discloses a heat exchanger of particular construction and methods of using same, the exchanger having pairs of sealing elements through which a circulating fluid is passed. The circulating fluid can be used for leak detection, cooling, or sterilization. The exchanger has a plurality of coaxially arranged tubes of thermally conductive material, the tubes being spaced apart radially by a pair of end manifolds to form annular fluid flow passages at least one of the manifolds having first and second sealing elements for forming seals between the manifold and the ends of the tubes, circumferential fluid passages being defined between the first and second sealing elements, circulating fluid inlet means for admitting a circulating fluid at first locations in the passages, and circulating fluid outlet means for discharge of said circulating fluid at second locations in said passages, the first and second locations being circumferentially spaced for each passage.

Abstract: Improved double wall tubing assembly which is especially useful in heat exchangers of the "coil-in-can" type for solar applications has a double wall construction which insures that a leak developing from a failure in either of the walls will not result in a mixing of fluid external to the outer tube with the fluid flowing internally of the inner tube. An outwardly projecting helical fin configuration formed on the outer surface of the inner tube provides an effective heat transfer medium between the inner and outer walls of the tube assembly while defining a spiral flow channel through which leakage entering through either wall can flow and be detected. A method of making the double wall tube assembly is disclosed wherein a finned outer tube is assembled over a previously finned inner tube. The assembled tubes are then brought into firm mechanical contact by the step of forming the assembled tubes into a coil and/or by expanding the inner tube.

Abstract: What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

Abstract: The invention concerns a vaulted cover to close a vertical recess in a pressure vessel with a plurality of fittings welded to the cover for the passage of steam pipes and with heat insulation applied to the inside of the cover consisting of a thermally insulating material and a plurality of rectangular cover plates arranged on the thermally insulating material, wherein the cover plates are fastened to the cover by means of holding bolts penetrating the entire insulation.

Abstract: A heat transfer device having an augmented surface is disclosed. The device comprises a base wall of heat conductive material having a plurality of pyramid-fins formed integrally with the surface of the base wall. The pyramid-fins are regularly spaced apart in the range of about 80-500 pyramid-fins per square inch and have a height in the range of 0.015 to 0.040 inch. The base wall is preferably a cylindrical tube and the pyramid-fins are formed as a knurled diamond pattern around the outside periphery of the tube.

Abstract: The piston compressor has a cylindrical block with at least one cylinder lining in which a piston moves without making contact. A collecting chamber for leakage gases which escape along the piston is provided at an end of the cylinder liner remote from the compression chamber. The cylinder liner is double walled to form a chamber through which forced coolant can be passed. In addition, an annular space is provided between the cylinder liner and the cylinder block to prevent leaking gas from passing into the cooling water contained in the cylinder block or cylinder liner.Forced cooling results in a good direct cooling of the cylinder liner.

Abstract: A vented heat transfer tube assembly comprising a pair of fluid circulation tubes disposed co-axially one within the other, the inner tube being double-walled and held substantially concentric within the outer tube by a plurality of pairs of diametrally opposed depressions or dimples formed in the peripheral surface of the outer tube at regular intervals. Each depression or dimple projects inwardly such as to engage and indent the peripheral surface of the inner tube and to cause a corresponding portion of the inner tube to bulge inwardly during forming of the dimples in the periphery of the outer tube.

Abstract: When plate heat exchangers are used with hazardous fluids the gasketing at the periphery may be replaced by welding the plates in pairs, with elastomeric gaskets between adjacent packs of plates. However, it is still necessary to have a gasket around the through holes (6) for the hazardous medium to seal them from the other medium. In accordance with the present invention, these gaskets are of duplex form (8, 9) with a sealed space (11) between the gasketing. In order to detect leakage into the sealed space a diluent fluid may be circulated through the sealed spaces and a detector, refer to FIG. 2.

Abstract: A leak detection system 40 particularly suited for employment in a steam generator 10 of the type that embodies at least one tube sheet 34 or 36 to which ends of a multiplicity of elongated tubular members 32 are suitably secured. The subject leak detection system 40 is operative both for purposes of detecting the occurrence of leaks in the steam generator 10 as well as for purposes of enabling a determination to be made as to the probable location of the leaks and the direction of flow of the leaking fluid.

Abstract: Method and apparatus for providing a controlled pressure liquid circulation system comprising a circulation conduit through which a liquid can be circulated and recirculated to accomplish a desired function, such as heating and/or cooling of a work station such as a mold. The invention involves opening and closing said circulation conduit to a source of supply liquid, such as city water, at elevated pressure while maintaining the controlled pressure of the liquid within said circulation conduit at a substantially lower pressure, and is characterized by maintaining the circulation conduit open to a drain line at all times and providing or maintaining a drain pressure which is at least slightly above atmospheric and is equal to the pressure desired within the circulation conduit in the area thereof which is open to the drain.

Abstract: A heat exchanger having an outer shell member and having a helically wound volute member which is double walled and includes a finned outer tube and a close-fitting inner tube, and the heat exchanger further including a core member which extends through the helical volute member and closes its central aperture to confine the flow of liquid in the outer shell member to flow through the fins, rather than pass through the aperture through the center of the helical volute member. The fins on the double walled volute member are wound as close to touching the core member as possible and the diameter of the core member and of the outer shell member is such that the fins closely fit the space between them. Both the finned tube and the inner tube pass completely through the shell member, and the finned outer tube is soldered to the shell so that any leakage between the tubes will pass outside the heat exchanger shell member rather than mixing the heat exchanger liquids.

Abstract: A double-walled finned heat transfer tube is provided for use in heat exchangers. The heat transfer tube includes an inner tube inserted within an externally finned outer tube. The assembly is subjected to a crimping operation which produces radial convexities along the length of the outer tube which serve to lock the inner tube and outer tube together in intimate heat conducting relationship and which produces radial concavities between the inner and outer tubes which serve as leakage channels. The crimping operation also produces grooves in the external finned surface which improves heat transfer between the assembly and an external medium.

Abstract: A motor vehicle, especially a truck, with a cooling device for an internal combustion engine is disclosed. The cooling device comprises at least one heat exchanger which is mounted in an elevated position on top of or behind a cab of the vehicle. A liquid-collecting container is located at least beneath the heat exchanger of the cooling device to protect the vehicle occupants against scalding in the event the heat exchanger is damaged as in an accident.

Abstract: Improved double wall tubing assembly which is especially useful in heat exchangers of the "coil-in-can" type for solar applications has a double wall construction which insures that a leak developing from a failure in either of the walls will not result in a mixing of fluid external to the outer tube with the fluid flowing internally of the inner tube. An outwardly projecting helical fin configuration formed on the outer surface of the inner tube provides an effective heat transfer medium between the inner and outer walls of the tube assembly while defining a spiral flow channel through which leakage entering through either wall can flow and be detected. A method of making the double wall tube assembly is disclosed wherein a finned outer tube is assembled over a previously finned inner tube. The assembled tubes are then brought into firm mechanical contact by the step of forming the assembled tubes into a coil and/or by expanding the inner tube.

Abstract: A double wall heat exchanger for use in solar heaters and the like. An outer drawn copper tube of predetermined thickness and inside diameter is slid over a second drawn copper tube also of a predetermined thickness and outside diameter. The tubes are then placed in a furnace and annealed for a specified time and temperature. The double wall tubes are placed in a finning machine. Under a specified pressure and at a specified feed rate, integral fins are formed on the outside tube. While the fins are being formed on the outside tube, internal pressure is being applied forcing the inner tube to expand and conform to the inside diameter of the outer tube. The mating surfaces form a helical passageway which serves as the path of leakage. The double wall heat exchanger has good surface contact between the tubes, has a path of leakage between the tubes at a pressure differential of 10 psig, and has good heat transfer.

Abstract: A stave cooling device includes a double drawn steel tube cast-mounted in a castable metal main body, and the double tube includes an inner tube which serves as a passage for a coolant. The inner tube of the double tube contains 0.20 to 0.38% of equivalent carbon and an outer tube of the double tube contains 0.15 to 0.25% of equivalent carbon. The outer tube has on its outer surface an alumina coating of 0.08 to 0.25 mm thick, and the main body is formed by casting a spheroidal graphite cast iron. The double tube is cast-mounted in the main body such that the double tube and the main body are not welded together.

Abstract: A heat exchanger having an outer shell member and having a helically wound volute member which is double walled and includes a finned outer tube and a close-fitting inner tube, and the heat exchanger further including a core member which extends through the helical volute member and closes its central aperture to confine the flow of liquid in the outer shell member to flow through the fins, rather than pass through the aperture through the center of the helical volute member. The fins on the double walled volute member are wound as close to touching the core member as possible and the diameter of the core member and of the outer shell member is such that the fins closely fit the space between them. Both the finned tube and the inner tube pass completely through the shell member, and the finned outer tube is soldered to the shell so that any leakage between the tubes will pass outside the heat exchanger shell member rather than mixing the heat exchanger liquids.

Abstract: A tubular heat exchanger, the core of which is comprised of two sets of U-shaped tubes facing in opposite directions. A header plate receives the ends of one set of tubes. Another, longitudinally spaced, header plate receives the ends of the other set of tubes, and the sets of tubes between the header plates are in a substantially interfitting relation. A manifolding means at the one header plate provides for flow of a first fluid at one temperature into the one ends of the one set of tubes and out the other ends thereof. Other manifolding means at the other header plate provides for similar flow of a second fluid at a different temperature through the other set of tubes. Intermediate their ends, the tubes of the different sets are in a nested, companion relation promoting a transfer of heat between the different flowing fluids. The core can be surrounded by a shell apertured for venting or draining of a leaked fluid or for flow of a third fluid over and around the assembled tubes.

Abstract: A two liquid heat exchange system, and a safety valve to prevent contamination of one liquid (first liquid) by the other. In systems such as hydronic solar systems, it is customary for a first liquid to be heated and run through a heat exchanger where its heat is transferred to a second liquid, often in a storage tank. This invention provides a safety valve which dumps the first liquid in case the pressure of the second liquid does not exceed the pressure of the first liquid by at least a predetermined difference.

Abstract: An assembly for revaporizing liquefied gases. The arrangement is of the running water type and includes a nest of tubes (1) preferably grouped to form panels and connected to inlet and outlet manifolds and over which water is caused to flow. To withstand the corrosion of salt water, an A-G4MC alloy is used and the cross-section of each tube 1 includes two diametrally opposite outer fins 2,3 and inner fins 5. Said tube is produced preferably by extrusion.Application to vaporization of natural gas.

Abstract: A heat exchanger having an outer shell which is long as compared with its diameter and having a helical double-walled finned volute member which is wound to a small diameter around a core member, the proportions being such that the fins on the double-walled member touch the core on the inside of the wound convolutions and touch the shell on the outside of the wound convolutions. The tube which comprises the outer wall of the double-walled member extends through the shell so that any leakage into the space between the inner and outer tubes of the double-walled tube member will be discharged outside of the shell. The process by which the exchanger is made includes the steps of inserting an inner tube in a length of finned outer tube, winding them into a volute member, inserting a central core member therein, installing these members in a shell member and spinning the shell member closed to seal with the ends of the outer tubing of the volute member.

Abstract: A heat exchanger having an outer shell which is long as compared with its diameter and having a helical double-walled finned volute member which is wound to a small diameter around a core member, the proportions being such that the fins on the double-walled member touch the core on the inside of the wound convolutions and touch the shell on the outside of the wound convolutions. The tube which comprises the outer wall of the double-walled member extends through the shell so that any leakage into the space between the inner and outer tubes of the double-walled tube member will be discharged outside of the shell. The process by which the exchanger is made includes the steps of inserting an inner tube in a length of finned outer tube, winding them into a volute member, inserting a central core member therein, installing these members in a shell member and spinning the shell member closed to seal with the ends of the outer tubing of the volute member.

Abstract: A negative pressure cooling system for cooling passageways in plastic molds includes a closed reservoir that is maintained under a high vacuum by a vacuum fluid pump with the outlet of the cooling passageway being connected to the reservoir inlet and with the reservoir outlet being connected to the cooling passageway inlet through a pressure pump and a fluid pressure regulator.

Abstract: A system for cooling plastic molds with a flowing liquid while obviating leaking of the fluid and still enabling the mold to basically determine the quantity of liquid flowing, by providing a less than atmospheric pressure within the mold and increasing where needed, the cooling effect of the flowing liquid by in effect, providing a controlled adjustable air leak.

Abstract: A plate type heat exchanger is disclosed having flow passages extending beyond the area of heat transfer on at least one end. The extending ends of the flow passages serve as sacrificial inlets for flow of one of two fluids through the heat exchanger so that any leak resulting from flow erosion or from corrosion in the extending flow passages does not result in mixing of the two fluids.

Abstract: A special unitary heat exchange unit for safely heating potable water from the waste heat of a number of refrigeration units is formed of a large diameter pipe perhaps 4 to 10 inches in diameter and perhaps 6 to 20 feet in length to extend along a refrigeration rack. The water to be heated is passed through the length of the heat exchanger, which is essentially a cylindrical tank enclosing a number of small double walled coils each constituting a heat exchanger through which freon or other similar refrigeration gas is passed for cooling. The double walled coils include the inner tube which carries freon, and an intermediate buffer zone in which a non-poisonous heat transfer liquid is located.

Abstract: The tube sheet of a heat exchanger supports a plurality of tubes made from a material such as titanium. A shield is provided for the tube sheet and is welded to the tubes. The shield is made from the same material as the tubes and is spaced from the tube sheet to define a fluid chamber containing fluid at a pressure in excess of the pressure of the liquid flowing through the tubes.

Abstract: A straight shell and tube heat exchanger utilizing double wall tubes and three tubesheets to ensure separation of the primary and secondary fluid and reliable leak detection of a leak in either the primary or the secondary fluids to further ensure that there is no mixing of the two fluids.

Abstract: A heat exchanger plate cooperable with a plate of like configuration to form a pair of manifolds and a connecting passage with the plate also cooperable with another plate of another pair of like configuration so as to nest therewith to provide an adjoining double wall between separate passages formed by adjacent arranged pairs of plates.

Abstract: An improved arrangement for feeding a cool liquid into a pressure vessel and mixing the fed liquid with hot liquid contained therein includes a flow-shielding ejector thermal sleeve disposed partially within an inlet nozzle and surrounding a supply line through which the main feed flow is conducted to a sparger outlet port in the vessel. The sleeve is spaced radially inwardly from the inner surface of the nozzle to define a generally annular flow-through space therebetween. Cool leakage liquid flow is confined within the sleeve and ejected by the main feed flow from an ejector chamber formed around the port by a downstream portion of the sleeve. The ejective action of the main flow exiting the port additionally draws an insulating flow of hot liquid from the vessel sequentially upstream through the flow-through space, into the interior of the upstream portion of the sleeve, and downstream with the confined cool leakage flow, thereby substantially reducing cracking of the nozzle.

Abstract: A tube to composite tubesheet connection system for preventing fluid leakage from the shell to the tube side and from the tube side to the shell side of a shell and tube heat exchanger. Tubes are inserted through and fastened to an inner tubesheet structure. An outer tubesheet structure constituting a plurality of outer tubesheet covers cooperates with the tubes which protrude therethrough and with the inner tubesheet to form a plurality of cavities. The inter-tubesheet cavities about each row or column of tubes are interconnected in a variety of ways. Grooving at least one of the tubesheet structures about its tube holes provides groove-cavities which may be selectively interconnected by networks of holes formed in at least one of the tubesheet structures.

Abstract: A heat exchanger incorporating double-walled tubes utilizes three tube sheets to provide economical leak detection.

Abstract: A system having a tube-in-tube heat exchanger comprising three coaxial tubular members fitted one within the other with manifolding at each longitudinal end of the exchanger for the circulation of fluid through the outside tubular member in a counterflow direction to fluid passing through the inside tubular member such that heat is exchanged therebetween. A fluid is provided in the intermediate tubular member such that a leak in either the outer or inner tubular members can be detected. Each of the tubular members has integral radially inwardly projecting fins in its bore, the fins of the outer member being in good thermal contact with the intermediate member whose fins, in turn, are in good thermal contact with the inner member such that an effective heat flow path therebetween is provided.

Abstract: A pump/heat exchanger assembly has tubes with double walls, inner and outer respectively, the outer wall being provided with inner longitudinal grooves. The exchange occurs between a primary fluid circulating outside the said tubes and a secondary fluid circulating inside the said tubes. A plurality of the double-walled tubes are arranged in an annular space, each tube consisting of a plurality of interconnected tube sections, having horizontal curved portions and elbowed portions, the tube sections being joined together at the elbowed portions. At least one leakproof annular chamber is provided outside the annular space and connected thereto. Leaks in the said tubes, are detected by injecting an inert gas, under a given pressure, into the said annular chambers, and comparing the pressure of the gas in the chamber with a maximum and a minimum pressure.

Abstract: An improved arrangement for feeding a cool liquid into a pressure vessel and mixing the fed liquid with hot vessel-contained liquid includes an ejector thermal sleeve within an inlet nozzle. An upstream portion of the sleeve sealed to the nozzle surrounds a supply line through which a main feed flow is conducted to a sparger outlet port in the vessel. Cool leakage liquid flow is confined within the sleeve and ejected from an ejector chamber formed around the port by a downstream portion of the sleeve. The leakage liquid is ejected by and with the main feed flow away from the nozzle whereby thermal cycling and cracking thereof are substantially reduced.

Abstract: A heat exchange system having a first tube system of tubes which are interconnected to conduct a first fluid and a second tube system comprising tubes surrounding the tubes of the first system to conduct a second fluid in heat exchange relationship with the first fluid, the preferred embodiment of the tubes of the first system being double walled and shaped to provide a passage for the escape of any fluid leaking from an opening occurring in either the inner or outer wall of the tubes of the first system. In the preferred embodiment, the double walled tubes are concentric tubes spaced radially to permit formation of a spiral groove on one tube, preferably the outermost, which provides a spiral path between said tubes which is open to atmosphere at the ends. Detachable return elbows interconnect adjacent ends of the innermost tubes to effect a continuous path for the fluid therein and the elbows at one end are removable to facilitate cleaning said tubes.

Abstract: In a process for treating radioactive liquid waste having an evaporation concentration device, including a concentration vessel, and a steam heater having steam inlet and outlet lines and operating to heat, with heating steam, radioactive liquid waste in the evaporation concentration device so as to concentrate the waste, contamination of the entire steam heater system in the event of leakage is prevented or greatly reduced by the provision of: (1) a sluice valve in the steam outlet line near the heater; (2) a discharge line with a drain valve for discharging any waste fluid between the heater and the sluice valve; and (3) means for receiving radioactive waste discharged through the discharge line. In accordance with the process of the present invention, when the pressure within the steam heater is less than that within the concentration vessel, and the operation of the evaporation concentration device is to be resumed, the sluice valve is first closed and the drain valve is opened.

Abstract: A heat exchange system is provided which transfers the heat from a fluid discharged from a device that utilizes a heated fluid, to fresh fluid in order to increase the temperature of the fresh fluid prior to feeding it into a heating tank. Thus, less energy is required to heat the fluid in the heating tank prior to its introduction into the device which utilizes heated fluid. After the heat has been exchanged, the discharged fluid is then expelled from the system. A fluid trap controls the fluid level in the heat exchanger to assure maximum heat transfer capability. An antisiphon valve is provided in the fresh fluid input of the heat exchange coil in order to prevent discharged fluid from contaminating the fresh fluid source in the event of a rupture in the heat exchance coil.

Abstract: A system for detecting leaks in a duplex tube heat exchanger. A tube sheet is provided with a plurality of straight bores passing laterally through the tube sheet, a number of channels connecting with each bore, each of the channels communicating with an annular space between the inner and outer walls of a duplex tube and an elongated probe adopted to be inserted into each of said bores to communicate with one of the channels and thereby be used to detect which, if any, of the duplex tubes is leaking.

Abstract: A metallurgical vessel cooling system with cooling chambers provided on the wall of the vessel is arranged so that the cooling chambers can be quickly emptied of the cooling water by connecting the chambers to a pressure gas line. This system is particularly useful for one or more converters with a converter hood having cooling chambers extending in the generatrix direction and connected to horizontally extending coolant passages. These passages are in turn connected to a coolant supply system by means of coolant supply and drain lines. The supply or drain line contains supervisor or signalling devices for checking the pressure and/or temperature and/or amount of coolant. These signalling devices, in the case of a deviation from a predetermined value, actuate controls for separating the supply and drain means from the coolant supply system and connecting one of these conduit means to the pressure gas line.

Abstract: The present invention relates to a tube sheet comprising two parallel interspaced sheet members which are provided with aligned bores through which at least partly with interposition of sleeves, extend tubes or tube sections. The sleeves are provided with internal chambers which through openings in the sleeve wall communicate with the space between the sheet members. The tube plate according to the present invention is highly resistant to thermal shocks in that the internal chambers in the sleeves extend to beyond at least one of the sheet members, in particular the thermally heaviest loaded part.

Abstract: A tube sheet construction for heat exchangers, particularly those of the type which utilize immiscible fluid heat exchange media, is formed with a tube sheet base plate and with a plurality of heat exchange tubes extending along at least a portion of their lengths in sealed fluid-tight engagement through the tube sheet base plate. The base plate is provided with a series of internal ducts extending in flow communication with the exterior of the tubes at the portion of the length thereof in sealed engagement with the base plate. The ducts are in flow communication with the exterior of the base plate and permit leaking fluid heat exchange media to be detected and exhausted from the heat exchanger. The tube ends extend beyond the base plate and a tube sheet cover plate extends over the base plate and is rigidly connected thereto with the cover plate having the projecting ends of the tubes fixed thereto by welding or the like.

Abstract: A heat exchanger is provided having first and second fluid chambers for passing primary and secondary fluids. The chambers are spaced apart and have heat pipes extending from inside one chamber to inside the other chamber. A third chamber is provided for passing a purge fluid, and the heat pipe portion between the first and second chambers lies within the third chamber.

Abstract: The tank wall is provided with a cylindrical collar in which a perforated tube base is mounted; the base having a set of tubes passing through in gas-tight relation. A thin sheet metal membrane is secured peripherally on the tube base to form an enclosed gas-tight chamber through which the tubes pass. The membrane is also perforated to permit passage of the tubes in a gas-tight relationship. The enclosed chamber permits monitoring of the imperviousness of the connections between the tubes and the tube base.

Abstract: An illustrative embodiment of the invention has a group of three concentrically disposed banks of helical steam generator tubes. Shrouds interposed between each of these three tube banks establish liquid barriers between the individual banks that prevent liquid sodium (or other shell side working fluid) from enjoying free communication throughout all of the tube banks. In this way, potentially damaging leakage between the shell side working fluid and the water within one of the tube banks can be isolated through discontinuation of the shell side working fluid and feedwater flow to the leaking bank, thereby permitting the remaining sound tube banks to continue functioning.

Abstract: A heat exchanger in which water tubes are heated by liquid sodium which minimizes the results of accidental contact between the water and the sodium caused by failure of one or more of the water tubes. A cylindrical protective tube envelopes each water tube and the sodium flows axially in the annular spaces between the protective tubes and the water tubes.

Abstract: Apparatus responsive to leaks occurring in a heat exchanger between a first tubular passageway which transports a heat transfer fluid at a relatively low pressure and a surrounding concentrically second tubular passageway which transports a refrigerant at a relatively higher pressure and including a sensor positioned to respond to the occurrence of a leak permitting the refrigerant to pass into the first passageway, a relay which is actuated by the sensor upon detection of a leak, and a plurality of valves which may be selectively actuated to interrupt the flow of either or both fluids through the heat exchanger.