Concentric Pipe for Hot Isostatic Pressing
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Solution Overview
Problem
Large diameter pipes used for filling and evacuating containers in hot isostatic pressing are prone to weld failure and unpredictable collapse, complicating the manufacturing process and increasing the risk of clogging and bridging of powder material.
Innovation Solution
A pipe with a continuous outer and concentric inner wall defining a flow channel where the cross-sectional area increases from the inlet to the outlet, minimizing clogging and bridging, and allowing predictable collapse to reduce stress on the welds, featuring angled or conical walls and convolutions for controlled collapse and smooth flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a large diameter pipe is used for filling and evacuating, then powder material flow is improved and clogging is reduced, but the weld between pipe and canister becomes vulnerable to failure during hot isostatic pressing
Solution Approach 1:
The pipe is segmented into two concentric walls (outer wall and inner wall) defining an annular flow channel. This segmentation allows the pipe to maintain a large effective flow area while reducing the outer diameter, thereby improving powder flow without compromising weld integrity during hot isostatic pressing.
Solution Approach 2:
The invention transitions from a single-wall pipe to a dual-wall annular structure, utilizing the radial dimension to create an annular flow channel. This dimensional change enables the pipe to provide sufficient flow area through the annular space while maintaining a smaller overall diameter for reliable welding.
2Productivity
If a large diameter pipe is used, then evacuation efficiency is improved, but the pipe collapses in an unpredictable manner causing unpredictable forces on the weld
Solution Approach 1:
The pipe wall is segmented into outer and inner walls with a defined spacing, creating an annular structure. This segmentation provides structural stability during collapse while maintaining adequate flow area, making the collapse behavior more predictable and controllable during hot isostatic pressing.
Solution Approach 2:
The pipe walls are designed as thin-walled structures that can flex and collapse in a controlled manner. The annular configuration with specific wall thicknesses allows predictable collapse behavior while maintaining evacuation efficiency during the pressing cycle.
3Reliability
If multiple smaller diameter pipes are used instead of a single large pipe, then weld reliability is improved, but the manufacturing process becomes more complex with increased number of welds
Solution Approach 1:
The invention merges multiple flow paths into a single annular flow channel between concentric walls. This combines the benefits of smaller pipe reliability with the flow capacity of a larger pipe, reducing the number of welds required while maintaining both reliability and productivity.
Solution Approach 2:
The annular pipe structure serves multiple functions simultaneously: it provides adequate flow area for powder filling and gas evacuation, maintains weld reliability through reduced diameter, and simplifies manufacturing by requiring only a single weld connection to the canister.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables free flow of powder material with reduced clogging and bridging, and predictable pipe collapse, thereby reducing weld failure rates and simplifying the manufacturing process.
Implementation Method 1
providing a pipe having two concentric walls defining a flow channel where the (radial) cross section (and volume) of the flow channel increases from the inlet to the outlet allows free flow of powder material from the inlet to the outlet with minimal clogging, bridging or 'rat-holing' of the powder material
Implementation Method 2
because the flow channel has a reduced radial dimension, the pipe collapses in a more predictable manner thus allowing for improved prediction of the stresses on the join between the pipe and the container
Data Source
AI summary
The present invention provides a pipe for transferring powder material from a reservoir to a container e.g. prior to hot isostatic pressing. The pipe comprises a continuous outer wall and a concentric continuous inner wall enclosed within and spaced from the outer wall. The spacing between the inner and outer walls defines a flow channel extending from an inlet to an outlet. The radial cross sectional area of the outlet is greater than the cross sectional area of the inlet.