CN104949562A - Inner and outer double-rifle pipe - Google Patents

Abstract

The invention discloses an inner and outer double-rifle pipe. At least two leftward-spiral or rightward-spiral rifle grooves a are formed in the outer surface of a pipe body in a rolling mode, and the cross sections of the rifle grooves a are circular arc lines. The capability of expansion and shrinkage of the pipe body is improved through the rifle grooves a, and the expansion self-cleanliness capability of the pipe body is improved. Meanwhile, when the pipe body is thermally expanded or stretched, the rifle grooves a can extend in the stress direction, and on the contrary, when the pipe body is frozen and shrunk, the rifle grooves a can be shrunk in the stress direction. In the rolling forming process, a passivation layer also called a metal surface layer film on the surface of the pipe body cannot be damaged, any machining stress cannot exist, and the service life is prolonged. The inner and outer double-rifle pipe can be widely applied to heat exchangers, condensers, heaters and the like, the market prospects are wide, and economic benefits are high.

Description

Inside and outside two rifled pipe

Technical field

The invention belongs to the parts of interchangeable heat exchange or heat-transfer equipment, being specifically related to a kind of longitudinal section has wrinkle or ripply pipe fitting.

Background technology

At present, the various heat-transfer pipes that market is sold, heat exchanger tube and all kinds of fluid hose, majority rotates and roll extrusion or utilize comparatively sharp cutter to take turns (Lathetool wheel) to cut at outer surface of pipe fittings and press out single or many helixes or thread groove at outer surface of pipe fittings by being similar to pawl dish above lathe.

Because cutter wheel (Lathetool wheel) cuts the single or many helixes or thread groove that press out, mechanical performance and the service life of pipe fitting are had a strong impact on, when in use, velocity of medium is very fast, when temperature is higher or pressure is larger, cut the single or many helixes that press out or thread groove place because being subject to mechanical damage very easily appearance point corrosion, slight crack or fracture, cause in pipe, the medium mixing of outer both sides, common stable needs simple shutdown maintenance, but different medium or there is corrosivity, poisonous and hazardous medium and can occur chemical reaction medium mixing time, inconceivable accident will be there is, production life security can be had a strong impact on, reduce production efficiency, add potential safety hazard, cause the wasting of resources greatly.

In addition, owing to being subject to pawl dish and the quantitative limitation of cutter wheel (Lathetool wheel) number, the pipe of caliber Φ >=38mm can not be processed.Meanwhile, heat-transfer pipe, heat exchanger tube or fluid hose, because of the increase of caliber, cut the single or many helixes that press out or thread groove also cannot meet technical requirement, cannot realize turbulent flow required in hydrodynamics and thermal conduction study or turbulent condition.

Common heat-transfer pipe, heat exchanger tube or fluid hose, through certain technological transformation processing, all can change the liquid form of medium, but all cannot accomplish to change liquid form, not destroy again the original mechanical performance of pipe and service life.

Summary of the invention

Technical problem to be solved by this invention is the shortcoming overcoming existing heat-transfer pipe, heat exchanger tube or fluid hose, provides that a kind of cost is low, heat exchange efficiency is high, inside and outside pair of rifled pipe of long service life.

Solving the problems of the technologies described above adopted technical scheme is: have the reflex wire casing a being at least 2 left-handed or dextrorotation in outer surface of tube body roll extrusion, the cross section of reflex wire casing a is circular arc line.

The angle β that twines of reflex wire casing a of the present invention is 50 ° ~ 80 °, twines apart from L to be

$L=\frac{d\mathrm{\π}}{tg\mathrm{\β}}$

In formula, L is for twining distance, and d is the external diameter of body 1, and β is for twining angle.

The angle β that twines of reflex wire casing a of the present invention is 65 °.

The central angle alpha of circular arc line of the present invention is 90 ° ~ 150 °, radius R is 5 ~ 20mm.

The cross section of reflex wire casing a of the present invention is circular arc, and the central angle alpha of circular arc is 120 °, radius R is 12mm.

The characteristic (density, viscosity, concentration etc.) of the medium that the present invention circulates according to inside and outside and the pressure of medium and flow velocity and flow, select different to twine angle β.When internal circulation medium is the less liquid of water that gas, gas or temperature, pressure are larger and other viscosity, density, selects to twine inside and outside pair of rifled pipe of β >=55, angle °, supercharging can be reached, improve the effect of flow velocity; When internal circulation medium is the larger liquid of water that gas-liquid mixtures, vapour-gas mixture or temperature are lower and other viscosity, density; select the inside and outside pair of rifled pipe twining angle β < 55 °; decompression can be reached, reduce the effect of flow velocity; play protection body, improve the service life of body.

In practical application, under the effect of the reflex wire casing a of recessed convex outside, the medium of tubular body circulation is dispersed into multiply, the medium of outside circulation can form strong cross-flow, reduce and be thinned the thickness in boundary layer, improve heat exchange efficiency during heat exchange, and many reflex wire casing a add the ability of the dilation of body, improve the ability that the expansion of body is self-cleaning; Meanwhile, when body expanded by heating or stretching, many reflex wire casing a can comply with Impact direction and extend, and on the contrary, during by cold events, also can comply with Impact direction and tighten.The present invention is in roll-forming process, any destruction can not be produced to the passivation layer of tube surfaces (being also metal watch tunic), any machining stress can not be there is, extend service life, the present invention can be widely used in heat exchanger, condenser, heater etc., wide market, high financial profit.

Accompanying drawing explanation

Fig. 1 is the structural representation of one embodiment of the invention.

Fig. 2 is the left view of Fig. 1.

Detailed description of the invention

Below in conjunction with drawings and Examples, the present invention is described in more detail, but the invention is not restricted to following embodiment.

Embodiment 1

To have 2 reflex wire casing a in the outer roll extrusion of body 1, the structure of inside and outside pair of rifled pipe is as follows:

In Fig. 1,2, the inside and outside pair of rifled pipe of the present embodiment is made up of body 1, has 2 reflex wire casing a in the outer surface roll extrusion of body 1, and the direction of rotation of reflex wire casing a is dextrorotation, and the angle β that twines of reflex wire casing a is 65 °, twines apart from being:

$L=\frac{d\mathrm{\&pi;}}{tg\mathrm{\&beta;}}$

In formula, d is the external diameter of body 1, and β is for twining angle.The cross section of reflex wire casing a is circular arc, and the right central angle alpha of circular arc is 120 °, and arc radius R is 12mm.Above-mentioned twine angle β, the design parameter twined apart from the right central angle alpha of L, circular arc, arc radius R specifically determines that according to the outside diameter d of body 1 inside and outside pair of rifled pipe of this structure can reach supercharging, improve the effect of flow velocity.

Embodiment 2

To have 2 reflex wire casing a in the outer roll extrusion of body 1, the structure of inside and outside pair of rifled pipe is as follows:

Have 2 reflex wire casing a in the outer surface roll extrusion of body 1, the direction of rotation of reflex wire casing a is dextrorotation, and the angle β that twines of reflex wire casing a is 50 °, twines apart from being:

$L=\frac{d\mathrm{\&pi;}}{tg\mathrm{\&beta;}}$

In formula, L is for twining distance, and d is the external diameter of body 1, and β is for twining angle.The cross section of reflex wire casing a is circular arc, and the right central angle alpha of circular arc is 90 °, and arc radius R is 5mm.Inside and outside pair of rifled pipe of this structure, can reach decompression, reduce the effect of flow velocity, plays the service life that protection body 1 improves body 1.

Embodiment 3

To have 2 reflex wire casing a in the outer roll extrusion of body 1, the structure of inside and outside pair of rifled pipe is as follows:

Have 2 reflex wire casing a in the outer surface roll extrusion of body 1, the direction of rotation of reflex wire casing a is dextrorotation, and the angle β that twines of reflex wire casing a is 80 °, twines apart from being:

$L=\frac{d\mathrm{\&pi;}}{tg\mathrm{\&beta;}}$

In formula, L is for twining distance, and d is the external diameter of body 1, and β is for twining angle.The cross section of reflex wire casing a is circular arc, and the right central angle alpha of circular arc is 150 °, and arc radius R is 20mm.

Embodiment 4

To have 6 reflex wire casing a in the outer roll extrusion of body 1, the structure of inside and outside pair of rifled pipe is as follows:

In above embodiment 1 ~ 3, have 6 reflex wire casing a in the outer surface roll extrusion of body 1, the direction of rotation of reflex wire casing a is dextrorotation, reflex wire casing a twine angle β, twine apart from L identical with corresponding embodiment.The cross section of reflex wire casing a is circular arc, and the right central angle alpha of circular arc, arc radius R are identical with corresponding embodiment.

Embodiment 5

To have 8 reflex wire casing a in the outer roll extrusion of body 1, the structure of inside and outside pair of rifled pipe is as follows:

In above embodiment 1 ~ 3, have 8 reflex wire casing a in the outer surface roll extrusion of body 1, the direction of rotation of reflex wire casing a is dextrorotation, reflex wire casing a twine angle β, twine apart from L identical with corresponding embodiment.The cross section of reflex wire casing a is circular arc, and the right central angle alpha of circular arc, arc radius R are identical with corresponding embodiment.Inside and outside pair of rifled pipe of this structure, adds the dilation ability of body 1, improves the expansion self-cleaning ability of body 1.

Embodiment 6

In above embodiment 1 ~ 5, have 8 reflex wire casing a in the outer surface roll extrusion of body 1, the direction of rotation of reflex wire casing a is left-handed.Reflex wire casing a twine angle β, twine apart from L identical with corresponding embodiment.The cross section of reflex wire casing a is circular arc, and the right central angle alpha of circular arc, arc radius R are identical with corresponding embodiment.Inside and outside pair of rifled pipe of this structure, adds the dilation ability of body 1, improves the expansion self-cleaning ability of body 1.

Claims (5)

1. a two rifled pipe inside and outside, is characterized in that: have reflex wire casing (a) being at least 2 left-handed or dextrorotation in body (1) outer surface roll extrusion, the cross section of reflex wire casing (a) is circular arc line.

2. inside and outside two rifled pipe according to claim 1, is characterized in that: the angle β that twines of described reflex wire casing (a) is 50 ° ~ 80 °, twines apart from L to be

$L=\frac{d\mathrm{\&pi;}}{tg\mathrm{\&beta;}}$

In formula, L is for twining distance, and d is the external diameter of body (1), and β is for twining angle.

3. inside and outside two rifled pipe according to claim 2, is characterized in that: the angle β that twines of described reflex wire casing (a) is 65 °.

4. inside and outside two rifled pipe according to claim 1, is characterized in that: the central angle alpha of described circular arc line is 90 ° ~ 150 °, radius R is 5 ~ 20mm.

5. inside and outside two rifled pipe according to claim 1, is characterized in that: the cross section of described reflex wire casing (a) is circular arc, the central angle alpha of circular arc is 120 °, radius R is 12mm.