A shell and tube longitudinal flow heat exchanger comprising a containment casing within which a first fluid can flow substantially parallel to the longitudinal axis of said casing, said containment casing accommodating in its interior a bundle of tubes substantially parallel to one another and parallel to the longitudinal axis of said casing and a plurality of grid-shaped baffles substantially transverse to the longitudinal axis of said casing supporting said tubes, a second fluid flowing in said bundle of tubes. Said tubes are provided on at least a part of their outside surface with a plurality of low fins, which are helically arranged on the outer surface of said tubes with a first angle of advancement a and having a profile interrupted by helical grooves having a second angle of advancement , with .

In order to provide an economical method for producing a weapon barrel, in which a considerable plasticisation of the barrel inner wall and thus of the twist profile is avoided when armour-piercing ammunition is shot, in particular in the case of an intense firing sequence, it is proposed not to introduce the twist profile of the weapon barrel into a barrel blank, the material of which has its end strength already as a result of hardening and tempering, but has a lower strength level (approximately 800-1000 MPa). Only once the twist profile has been formed by extrusion or hammering is the steel hardened and tempered to a predefined strength value >1000 MPa, and is the barrel blank that is provided with the twist profile mechanically processed further.

An apparatus for producing an inner spiral grooved tube, the apparatus includes first and second bobbins, one of which is an unwinding bobbin and the other of which is a winding bobbin; a floating frame that supports a shaft of the first bobbin; a rotary shaft that supports the floating frame though bearings and rotates in a direction perpendicular to an axis of a bobbin in the floating frame; a revolving flyer configured to invert a tube route of a tubular material between the first bobbin and the second bobbin, to convey the tubular material, and to revolve the tubular material around the floating frame as being supported by the rotary shaft; and first and second drawing dies positioned on a front stage and a rear stage of the revolving flyer, respectively, in the tube route of the tubular material

A heat transfer tube including an inner surface including a plurality of grooves. The plurality of grooves includes at least primary grooves and secondary grooves, wherein the primary grooves extend axially along a length of the tube, and the secondary grooves intersect the primary grooves.

The invention relates to a method and a device for producing a circular-cylindrical body (4) which consists of a plastic compound and which has at least one helical inner recess that runs in the interior of the body. The method has the following steps: producing a circular-cylindrical body (4), which consists of a plastic compound and which has at least one linear inner recess that runs in the interior of the body, by means of an extrusion molding die (1), discharging the circular-cylindrical body (4) out of the extrusion molding die (1) via a twisting section (7) onto a holding and transporting device (2) which is designed to hold and transport the circular-cylindrical body (4) and which can be rotated about the longitudinal axis of the holding and transporting device, twisting the circular-cylindrical body (4) on the twisting section (7) in order to form the at least one helical inner recess by rotating the holding and transporting device (2) together with the circular-cylindrical body being held and transported in the holding and transporting device, and discharging the circular-cylindrical body (4), which has at least one helical inner recess running in the interior of the body, out of the holding and transporting device (2) onto a storage device (3).

A device for forming inside three-dimensional finned tube by multi-edge ploughing and extruding, comprises a machine frame, a machine head, a supporting mechanism, an axial feeding mechanism and a cutter assembly for forming inside fins. The machine head, the supporting mechanism and the axial feeding mechanism are axially mounted on the machine frame in sequence. The cutter assembly for forming inside fins is mounted on the feeding mechanism. One end of a metal tube to be machined for forming inside three-dimensional fins is clamped on a chunk of a rotary main shaft of the machine head, and the other end thereof is placed on the supporting mechanism. The rotary main shaft of the machine head provides the rotation power for the metal tube, and the axial feeding mechanism drives the cutter assembly to move linearly along a coaxial line of the metal tube and the cutter assembly.

The production method for producing a rifled tube, which includes a plurality of first helical ribs on its inner surface, includes: a steps of: preparing a steel tube; and producing a rifled tube by performing cold drawing on a steel tube by using a plug which includes a plurality of second helical ribs, the plug satisfying Formulae and:
0.08 <W(AB)N/(2A)<0.26(1)
0.83<S(AB)N/(2M)<2.0(2)
where, W is a width of a groove bottom surface of the helical groove; A is a maximum diameter of the plug; B is a minimum diameter of the plug; N is a number of the second helical ribs; S is the width of the groove bottom surface; and M is a pitch of adjacent second helical ribs.

A heat transfer tube including an inner surface including a plurality of grooves. The plurality of grooves includes at least primary grooves and secondary grooves, wherein the primary grooves extend axially along a length of the tube, and the secondary grooves intersect the primary grooves.

A process heat exchange rod for cooling or heating liquids in a process vessel. The rod may have a linear form and extend downward through an upper wall of the process vessel into proximity with the lower floor. The rod internally defines a circulatory flow path for the heat exchange medium, including an outer jacket and a flow diverter having a central through bore and external helical flutes. Heat exchange medium travels down through the central through bore and then back up through helical grooves formed between the flow diverter and the outer jacket, or vice versa. Accurate heating or cooling of the process fluid is attained by modification of the configuration of the heat exchange rod as well as the flow rate and temperature of the heat exchange medium. The components may be injection molded of a polymer, often transparent, having a high heat transfer coefficient.

A method for forming features in an exterior surface of a heat transfer tube includes forming a plurality of channels into the surface, where the channels are substantially parallel to one another and extend at a first angle to a longitudinal axis to the tube. A plurality of cuts are then made into the surface substantially parallel to one another and extend at a second angle to a longitudinal axis to the tube different from the first angle. Individual fin segments extend from the surface and are separated from one another by the channels and the cuts. The fin segments have a first channel-adjacent edge adjacent substantially parallel to the channel, a first cut-adjacent edge substantially parallel to the cut, and a corner formed by a second channel-adjacent edge and a second cut-adjacent edge. A tube formed using this method can be used as a condenser tube.