A double pipe type heat exchanger includes an inner pipe having a first flow path defined therein and an outer pipe arranged around the inner pipe to define a second flow path between the inner pipe and the outer pipe. The inner pipe includes a spiral groove formed on an outer circumferential surface of the inner pipe to extend along a longitudinal direction of the inner pipe. The outer pipe includes a reduced diameter portion protruding inwardly so that the inner surface of the outer pipe is intermittently contacted with the outer circumferential surface of the inner pipe.

A heat exchanger is provided including a first manifold and a second manifold separated from the first manifold. A plurality of heat exchange tube segments are arranged in spaced parallel relationship and fluidly couple the first and second manifold. Each of the plurality of tube segments includes a first heat exchange tube and a second heat exchange tube at least partially connected by a web extending there between. The plurality of heat exchange tube segments includes a bend defining a first section and a second section of the heat exchange tube segments. The first section is arranged at an angle to the second section. A plurality of first fins extends form the first section of the heat exchange tube segments and a plurality of second fins extends from the second section of the heat exchange tube segments.

A heat receiver tube having first, second, and further partial heat receiver tube surfaces for absorbing and transferring solar energy to heat transfer fluid is presented. The first and further partial heat receiver tube surfaces are formed by solar absorptive coatings deposited on partial surfaces of core tube. The second partial heat receiver tube surface is formed by emission radiation inhibiting coating deposited on second core tube surface for inhibiting emissivity for infrared radiation. The further partial heat receiver tube surface is arranged in radiation window of second partial heat receiver tube surface such that direct sunlight impinges further partial heat receiver tube surface. The heat receiver tube is arranged in focal line of parabolic mirror of parabolic trough collector. The first partial heat receiver tube surface and sunlight reflecting surface is arranged face to face, second and further partial heat receiver tube surfaces are averted to reflecting surface.

A heat receiver tube having first, second, and further partial heat receiver tube surfaces for absorbing and transferring solar energy to heat transfer fluid is presented. The first and further partial heat receiver tube surfaces are formed by solar absorptive coatings deposited on partial surfaces of core tube. The second partial heat receiver tube surface is formed by emission radiation inhibiting coating deposited on second core tube surface for inhibiting emissivity for infrared radiation. The further partial heat receiver tube surface is arranged in radiation window of second partial heat receiver tube surface such that direct sunlight impinges further partial heat receiver tube surface. The heat receiver tube is arranged in focal line of parabolic mirror of parabolic trough collector. The first partial heat receiver tube surface and sunlight reflecting surface is arranged face to face, second and further partial heat receiver tube surfaces are averted to reflecting surface.

The present disclosure relates to atomizers for an aerosol delivery device such as a smoking article. The atomizer may include a liquid transport element and a wire extending along at least a portion of a longitudinal length thereof. The wire may define contact portions configured to engage heater terminals and a heating portion configured to produce heat. The heating portion may include a variable coil spacing. In other atomizers, the wire may extend at least partially through the liquid transport element proximate the contact portions. Related inputs, cartridges, aerosol production assemblies, and methods of forming atomizers are also provided.

The present disclosure relates to atomizers for an aerosol delivery device such as a smoking article. The atomizer may include a liquid transport element and a wire extending along at least a portion of a longitudinal length thereof. The wire may define contact portions configured to engage heater terminals and a heating portion configured to produce heat. The heating portion may include a variable coil spacing. In other atomizers, the wire may extend at least partially through the liquid transport element proximate the contact portions. Related inputs, cartridges, aerosol production assemblies, and methods of forming atomizers are also provided.

A fintube includes a body having a first fin, a second fin and a tube section. A first overlap fold is provided between the first fin and the tube section. The first overlap fold includes an open groove. A second overlap fold is provided between the second fin and the tube section. A seam includes a second overlap fold received and held in the groove of the first overlap fold. Methods for making a fintube are also disclosed.

A fintube includes a body having a first fin, a second fin and a tube section. A first overlap fold is provided between the first fin and the tube section. The first overlap fold includes an open groove. A second overlap fold is provided between the second fin and the tube section. A seam includes a second overlap fold received and held in the groove of the first overlap fold. Methods for making a fintube are also disclosed.

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×(A−B)×N/(2π×A)<0.26  (1)

0.83<S×(A−B)×N/(2×M)<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.

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×(A−B)×N/(2π×A)<0.26  (1)

0.83<S×(A−B)×N/(2×M)<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.