Abstract: A shell and tube heat exchanger includes a plurality of tubes positioned inside a shell. A first type of tube has a first outer surface, and a second type of tube has a second outer surface, where the first outer surface is different than the second outer surface. The inner surface of the first type of tube is in liquid communication with the inner surface of the second type of tube, so fluid can flow between the inner surfaces of the different tube types.

Abstract: An improved tool assembly for enhancing the surface of a heat transfer tube is provided. The tool assembly includes rods having cutting tips and positioned in rod guides which are slidably positioned in shafts provided in a tool holder. In an equilibrium state, the cutting tips do not extend from the tool holder. When a force is applied to the rod guides, the rod guides move in a first direction along the shafts in the tool holder, resulting in exposure of the cutting tips which enhance the tube surface. When the force is removed from the rod guides, the rod guides move along the shafts in a direction opposite the first direction to retract the cutting tips within the tool holder. In this way, the cutting tips are protected when not in use.

Abstract: A condenser is made from a heat exchanger including a tube bundle within a shell. The tube bundle has an interior section within a periphery, and at least two sloped baffles are positioned in the tube bundle. Each sloped baffle has an inner edge which is within the tube bundle interior, and a gap is defined between the inner edges.

Abstract: The current invention includes a tube with a helical fin extending from the tube's outer surface. The fins and tube are monolithic, or formed of one part, with a channel defined between adjacent fins. The fin has a crest with peaks and depressions formed in the crest. The fin peak includes an indent formed in a side surface, and the indent includes a flank and a base surface. The indent flank intersects the fin peak top, and the indent base surface intersects the fin side wall.

Abstract: The current invention includes a tube with a helical fin extending from the tube's outer surface. The fins and tube are monolithic, or formed of one part. The fin is continuous and the fin base is essentially straight as it winds around the tube. The fin has a tip opposite the fin base with an essentially straight fin body as viewed between the tip and the base. The fin is bent into concave and convex shapes about the tube wall so the fin tip makes a wavy pattern as it winds around the tube.

Abstract: A tube used for heat transfer has adjacent fins extending from an outer surface of the tube with a channel between the fins. The fins include a roof formed over the channel, and holes penetrate the roof into the channel. The fin, including the roof, is monolithic with the tube body. Helical ridges are formed on a tube inner surface, and the tube body includes an indentation in the outer surface which extends the tube body inner surface towards a tube axis.

Abstract: A finned tube includes channels defined between adjacent fins on the tube body outer surface. Wings extend from side walls of the adjacent fins between the fin top and the fin base such that the wings form a barrier which splits the channel into an upper channel and a lower channel. A plurality of holes penetrate the barrier where the wings meet, so liquids and gases can pass into and out of the enclosed area defined by the lower channel. The wings can include alternating upper wings and lower wings, and there can be depressions formed in the fin top.

Abstract: The invention relates to enhanced heat transfer surfaces and methods and tools for making enhanced heat transfer surface. Certain embodiments include a boiling surface that include a plurality of primary grooves, protrusions and secondary grooves to form boiling cavities. The boiling surface may be formed by using a tool for cutting the inner surface of a tube. The tool has a tool axis and at least one tip with a cutting edge and a lifting edge. Methods for making a boiling surface are also disclosed, including cutting through the inner surface of a tube to form primary grooves, then cutting and lifting the inner surface to form protrusions and secondary grooves.

Abstract: An improved heat transfer tube, an improved method of formation and an improved use of such a heat transfer tube is disclosed. The heat transfer tube includes an outer surface with a plurality of radially outwardly extending helical fins, the fins being grooved to define notches, a plurality of channels extending between adjacent fins, at least one nucleate boiling pore formed at the intersection of a notch and a channel. The fins are flattened or pushed down to form a primary nucleate boiling cavity within the at least one nucleate boiling pore; and the tips of the fins are further bent over or flattened to form a secondary nucleate boiling cavity within the at least one nucleate boiling pore. Also disclosed are improved refrigerant evaporator including at least one such boiling tube and a method of making such a boiling tube.

Abstract: An improved heat transfer tube and a method of formation thereof. The inner surface of the tube is enhanced with a plurality of protrusions that reduce tube side resistance and improve overall heat transfer performance. The protrusions create additional paths for fluid flow within the tube and thereby enhance turbulence of heat transfer mediums flowing within the tube. This increases fluid mixing to reduce the boundary layer build-up of the fluid medium close to the inner surface of the tube, such build-up increasing the resistance and thereby impeding heat transfer. The protrusions also provide extra surface area for additional heat exchange. The method of this invention includes using a tool, which can easily be added to existing manufacturing equipment, having a cutting edge to cut through ridges on the inner surface of the tube to create ridge layers and a lifting edge to lift the ridge layers to form the protrusions.

Abstract: The present invention discloses an improved heat transfer tube, an improved method of formation, and an improved use of such heat transfer tube. The present invention discloses a boiling tube for a refrigerant evaporator that provides at least one dual cavity nucleate boiling site. The present invention further discloses an improved refrigerant evaporator including at least one such boiling tube, and the method of making such a boiling tube.

Abstract: An improved heat transfer tube and a method of formation thereof. The inner surface of the tube has a primary set of fins and an intermediate sets of fins positioned in the areas between the primary fins and at an angle relative to the primary fins. While intermediate fins may be used with primary fins arranged in any pattern, in a preferred embodiment of the inner surface tube design, the intermediate fins are positioned relative to the primary fins to result in a grid-like appearance. Tests show that the performance of tubes having the intermediate fin designs of the present invention is significantly enhanced. A first set of rollers creates the primary and intermediate fin designs on at least one side of a board. A second set of rollers may be used to further enhance the performance.

Abstract: Heat transfer tubes have an exterior surface in contact with a refrigerant and an interior surface defining a path through which a liquid is conveyed in an axial direction of the tube. The exterior surface of the tube has a plurality of fins formed thereon; the interior surface of the tube has a plurality of ridges formed thereon. The fins have an average width v with respect to the axial direction of the tube and a pitch Q with respect to the axial direction of the tube. A channel is provided between adjacent fins, the channels having a channel bottom of length L with respect to the axial direction of the tube. The ridges have a ridge height (e) and a ridge base width (b). The tubes have a ratio of L/v in a range of from 1.22 to 3.40. L is greater than 45% of fin pitch Q, and is preferably between 45% and 75% of fin pitch Q. A ratio of (e.times.L)/b is in a range of from 0.0062 to 0.0165; a ratio of e/b is in a range of from 0.565 to 0.973.

Abstract: Metallic tubes (10,10') for boiling have an outer surface (12) for contacting a refrigerant and an inner surface (14) for contacting a liquid heat transfer medium to be chilled. The outer surface (12) has a plurality of radially outwardly extending helical fins (18); the tube inner surface (14) has a plurality of helical ridges (16). The fins (18) of the outer surface are notched to provide nucleate boiling cavities having pores (30). The fins (18) and notches (N) are so spaced that the pores (30) have an average area less than 0.00009 square inches and a pore density of at least 2000 per square inch on the tube outer surface. The helical ridges (16) on the inner surface have a predetermined ridge height and pitch and are positioned at a predetermined helix angle, the inner surface having a severity factor .PHI. in the range of 0.006 to 0.008.

Abstract: Improved method and apparatus for making finned tubing from difficult to work materials such as titanium and stainless steel uses spaced sets of finning discs on a plurality of arbors to form a tube against a mandrel having different diameters under each set of discs. By forming the tube fin tips to their final O.D. in a first disc set and by deepening their roots to bring the fins to their final height in a second disc set, tubes with higher fin counts and/or higher fin heights can be achieved than were formerly possible. The process of separately cold working the tips and roots also permits tubes to be made which are dimensionally identical to prior art tubes but with higher quality and productivity since tube stresses are greatly reduced. An improved titanium tube is also disclosed which has at leasts 26 fins per inch, a fin height of at least 0.034" and an outside to inside surface area ratrio of at least 3.0.

Abstract: Improved heat transfer tube and method of making same has mechanical enhancements which can individually improve either the inner or outer surfaces or which can cooperate to increase the overall efficiency of the tube. The internal enhancement, which is useful on either boiling or condensing tubes, comprises a plurality of closely spaced helical ridges which provide increased surface area and are positioned at an angle which gives them a tendency to swirl the liquid. The external enhancement, which is applicable to boiling tubes, is provided by successive cross-grooving and rolling operations performed after finning. The finning operation, in a preferred embodiment for nucleate boiling, produces fins while the cross-grooving and rolling operation deforms the tips of the fins and causes the surface of the tube to have the general appearance of a grid of generally rectangular flattened blocks which are wider than the fins and separated by narrow openings between the fins and narrow grooves normal thereto.

Abstract: Improved method and apparatus for making finned tubing from difficult to work materials such as titanium and stainless steel uses spaced sets of finning discs on a plurality of arbors to form a tube against a mandrel having different diameters under each set of discs. By forming the tube fin tips to their final O.D. in a first disc set and by depending their roots to bring the fins to their final height in a second disc set, tubes with higher fin counts and/or higher fin heights can be achieved than were formerly possible. The process of separately cold working the tips and roots also permits tubes to be made which are dimensionally identical to prior art tubes but with higher quality and productivity since tube stresses are greatly reduced. An improved titanium tube is also disclosed which has at least 26 fins per inch, a fin height of at least 0.034" and an outside to inside surface area ratio of at least 3.0.

Abstract: Improved heat transfer tube and method of making same has mechanical enhancements which can individually improve either the inner or outer surfaces or which can cooperate to increase the overall efficiency of the tube. The internal enhancement, which is useful on either boiling or condensing tubes, comprises a plurality of closely spaced helical ridges which provide increased surface area and are positioned at an angle which gives them a tendency to swirl the liquid. The external enhancement, which is applicable to boiling tubes, is provided by successive cross-grooving and rolling operations performed after finning. The finning operation, in a preferred embodiment for nucleate boiling, produces fins while the cross-grooving and rolling operation deforms the tips of the fins and causes the surface of the tube to have the general appearance of a grid of generally rectangular flattened blocks which are wider than the fins and separated by narrow openings between the fins and narrow grooves normal thereto.

Abstract: Improved method and apparatus for making finned tubing from difficult to work materials such as titanium and stainless steel uses spaced sets of finning discs on a plurality of arbors to form a tube against a mandrel having different diameters under each set of discs. By forming the tube fin tips to their final O.D. in a first disc set and by deepening their roots to bring the fins to their final height in a second disc set, tubes with higher fin counts and/or higher fin heights can be achieved than were formerly possible. The process of separately cold working the tips and roots also permits tubes to be made which are dimensionally identical to prior art tubes but with higher quality and productivity since tube stresses are greatly reduced. An improved titanium tube is also disclosed which has at least 26 fins per inch, a fin height of at least 0.034" and an outside to inside surface area ratio of at least 3.0.