Connection between a cooled double-wall pipe and an uncooled pipe and double-pipe heat exchanger including said connection

1. Connection between a single wall of an uncooled pipe and two walls of a cooled double-wall pipe having a hollow space run through by a cooling fluid let into the hollow space and taken from the hollow space through side passages connected to a cooling fluid inlet duct and a cooling fluid outlet duct in a linear quench exchanger, said connection comprising

a connection zone with a longitudinal cross section generally in a fork form having a single tubular end connected by a weld to the uncooled pipe and an opposite double-wall tubular end connected to the two walls of the cooled double-wall pipe by plural welds so that a bottom of the fork form constitutes a terminal closing of the hollow space and a side passage is present at the connection to the double-wall pipe and a portion thereof nearest the uncooled pipe is almost at a height of the bottom of the fork.

2. Connection in accordance with claim 1 , wherein the side passage is a passage for entry of the cooling fluid into the hollow space.

3. Connection in accordance with claim 2 , further comprising a baffle arranged in the hollow space near the side passage to guide flow of cooling fluid near the fork form bottom.

4. Connection in accordance with claim 3 , wherein the baffle describes an arc of approximately 180° to embrace half of a circumference of an inner wall of the hollow space on a side of the side passage.

5. Connection in accordance with claim 3 , wherein the baffle is fastened on an external wall of the hollow space.

6. Connection in accordance with claim 2 , wherein a fork connection zone is realized with a separate connection member generally in a fork form at one end of which is located the uncooled pipe and at an opposite end of which is located the double-wall pipe with an external wall of said opposite end of the connection member there is said side passage.

7. Connection in accordance with claim 6 , wherein a welding zone between an external wall of the cooled double-wall pipe and the connection member is farther from the fork form bottom than a welding zone between an inner wall of the cooled double-wall pipe and the connection member.

8. Connection in accordance with claim 1 , wherein the side passage is a passage for outlet of the cooling fluid from the hollow space.

9. Connection in accordance with claim 1 , wherein the fork form bottom is nearly contained in a plane.

10. Connection in accordance with claim 9 , wherein the cooling fluid duct has near the side passage an axis nearly parallel to the plane of the bottom of the fork form.

11. Connection in accordance with claim 9 , wherein the plane of the bottom of the fork is perpendicular to an axis of the double-wall pipe.

12. Connection in accordance with claim 9 , further comprising a baffle arranged in the hollow space near the side passage to guide flow of cooling fluid near the fork form bottom, said baffle is nearly contained in a plane parallel to the plane of the fork form bottom.

13. Connection in accordance with claim 12 , wherein the baffle describes an arc of approximately 180° to embrace half of a circumference of an inner wall of the hollow space on a side of the side passage, and a thickness of the baffle is a little less than a thickness of the hollow space.

14. Connection in accordance with claim 1 , wherein the cooling fluid duct has near the side passage an axis nearly perpendicular to an axis of the cooled double-wall pipe.

15. Double-pipe linear quench heat exchanger comprising

a double-wall pipe for heat exchange between a fluid contained in an internal pipe of the double-wall pipe and fluid flowing in a hollow space between the internal pipe and an external pipe of the double-wall pipe with said double-wall pipe being connected by a weld to a single-wall pipe for inlet of fluid to be cooled through a first connection and being connected to a single-wall pipe by another weld for outlet of the cooled fluid through a second connection, said first connection between the single-wall pipe and the cooled double-wall pipe allowing the cooling fluid into the hollow space and taken from the hollow space through side passages connected to a cooling fluid inlet duct and a cooling fluid outlet duct, a connection zone with a longitudinal cross section generally in a fork form having a single tubular end connected to the single-wall pipe and an opposite double-wall tubular end connected to the cooled double-wall pipe by plural welds so that a bottom of the fork constitutes a terminal closing of the hollow space, a side passage being made at the first connection and a portion thereof nearest the single-wall pipe is almost at a height of the bottom of the fork.

16. Double-pipe linear quench heat exchanger in accordance with claim 15 , wherein the side passage is a passage for entry of the cooling fluid into the hollow space and the cooling fluid duct has near the side passage an axis nearly perpendicular to an axis of the cooled double-wall pipe.

17. Double-pipe linear quench heat exchanger in accordance with claim 15 , wherein the side passage is a passage for entry of the cooling fluid into the hollow space and in the hollow space is arranged a baffle near the side passage to guide the flow of cooling fluid near the fork bottom.

18. Double-pipe linear quench heat exchanger in accordance with claim 15 , further comprising second connection between the single-wall pipe and the cooled double-wall pipe having a portion thereof nearest the single-wall pipe being almost at a height of the bottom of the fork form.