Rotating Polymer Feed Tube for High-Pressure Pipe Joint Coating
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Solution Overview
Problem
Existing methods for coating welded pipe joints with polymer layers face challenges in maintaining high pressure and temperature resistance, leading to difficulties in achieving sufficient mass flow and movement of the coating nozzle, especially when dealing with large pipe diameters.
Innovation Solution
A rigid-walled feed tube system using conical roller bearings and journal bearings to connect the extruder to a movable coating nozzle, allowing for rotation around the pipe while preventing movement parallel to the longitudinal axis, thus maintaining pressure resistance and flexibility for large movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a flexible hose system is used to feed molten polymer to the moving nozzle, then the nozzle can move freely, but the system cannot withstand high pressure and temperature, leading to great pressure loss
Solution Approach 1:
The feed tube is divided into multiple rigid sections connected by articulation points with bearings, allowing the tube to bend and follow the nozzle movement while maintaining structural integrity for pressure and temperature resistance
Solution Approach 2:
The feed tube incorporates articulation points that enable dynamic bending and reconfiguration of the tube path as the nozzle moves, while rigid walls maintain pressure containment
2Quantity of substance
If the hose diameter is increased to reduce pressure loss, then sufficient mass flow can be achieved, but the hose becomes too large and difficult to handle for field conditions
Solution Approach 1:
The rigid feed tube is segmented into manageable sections that can be articulated and positioned as needed, reducing handling complexity while maintaining the large diameter required for sufficient mass flow
3Adaptability or versatility
If the extrusion nozzle and polymer feed are carried around the pipe, then coating can be applied to welded joints, but the method is slow due to frequent reservoir filling
Solution Approach 1:
The polymer reservoir is extracted from the moving nozzle assembly and placed in a fixed extruder, eliminating the need to carry and refill reservoirs during the coating process
Solution Approach 2:
The fixed extruder enables continuous polymer feed to the moving nozzle, eliminating interruptions for reservoir refilling and maintaining continuous coating application
4Reliability
If a rigid-walled feed tube system is used, then pressure and temperature resistance is maintained, but the system must allow for large movements around large pipe diameters
Solution Approach 1:
The rigid feed tube is divided into multiple straight sections connected by articulation points, allowing the segmented tube to bend and follow complex paths around large pipes while maintaining rigid walls for pressure resistance
Solution Approach 2:
The articulation points enable the feed tube to move in multiple dimensions and orientations, accommodating the three-dimensional movement required to coat joints on large-diameter pipes
Data Source
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AI summary
Device and connector tube for coating a pipe (1) or portion of a pipe, which has an outer surface determined by the outer circumference of the pipe (1) or portion of a pipe. The device comprises a moving device (5), which can rotate around the outer surface of the pipe (1) or portion of a pipe, and a coating nozzle (8), which is connected to a molten- polymer source (15) in order to form a polymer film, which nozzle (8) is attached to the device (5), which can rotate around the pipe. The feed tube (19, 20) forms at least part of the molten polymer's feed route from the source (15) to the coating nozzle, which feed tube comprises at least two rigid tubes (19) and at least one connector (20), which com¬ prises at least two connector parts (21; 24, 27) for connection to the tube (19) and a bearing arrangement (23) fitted between the connector parts, which permits the connector parts (21; 24, 27) to rotate around their common longitudinal axis and keeps the connector parts (21; 24, 27) parallel to each other.