Process Chamber Gas Flow Layout for Cleaner Powder Bed Fusion
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Solution Overview
Problem
In additive manufacturing, impurities generated during selective laser sintering or laser melting, such as splashes, fumes, and gases, negatively affect the manufacturing process by absorbing or deflecting the laser beam and depositing on building material layers, requiring efficient removal from the process chamber to maintain quality and efficiency.
Innovation Solution
A method and device for providing a flow in the process chamber with a main gas flow and a secondary flow, where a boundary zone is created between the main and secondary flows to enhance the removal of impurities by guiding and modifying the flow properties, using guide elements or adjusting the flow velocity and direction to improve the homogeneity and efficiency of the main flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a gas flow is introduced into the process chamber through a gas inlet in a lower altitude region and discharged through a gas outlet to generate a main flow, then impurities can be removed from the process chamber, but the main flow spreads into lateral regions and flow velocity decreases
Solution Approach 1:
The gas inlet is divided into multiple separate inlet openings arranged in a specific pattern, allowing the gas flow to be segmented into multiple streams that maintain higher velocities and reduce lateral spreading compared to a single large inlet
Solution Approach 2:
Different regions of the process chamber are provided with different flow characteristics by strategically positioning and sizing the inlet openings, creating localized flow patterns that optimize both impurity removal and velocity maintenance in different areas
2Ease of operation
If the gas inlet and gas outlet have a width smaller than the width of the process chamber, then the flow can be directed from inlet to outlet, but regions with no deliberate flow form at the sides, creating turbulences that negatively affect the main flow
Solution Approach 1:
The inlet openings are arranged asymmetrically or with different dimensions to create a flow pattern that naturally fills the process chamber width, preventing dead zones and lateral turbulences while maintaining directed flow from inlet to outlet
Solution Approach 2:
The gas flow is distributed across multiple inlet openings positioned at different locations, transforming a single-dimensional flow problem into a multi-dimensional flow pattern that covers the entire chamber width more uniformly and reduces lateral instabilities
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 method effectively improves the flow properties of the main gas flow, leading to enhanced removal of impurities and improved object quality by maintaining a stable and homogeneous flow, which reduces the impact of secondary flows on the main flow, thereby increasing the efficiency and quality of the additive manufacturing process.
Implementation Method 1
a process gas is supplied to the process chamber in a lower altitude region of the process chamber... and the process gas flows in a main flow from the gas inlet to the gas outlet
Implementation Method 2
a boundary zone is positioned at least in a section between the secondary flow and the main flow... due to at least one of the following influencing measures: positioning at least one guide element as boundary zone... with at least one guide face for guiding the main flow and/or the secondary flow
Data Source
AI summary
In a method of providing a flow for a process chamber of a device for producing a three-dimensional object by layer-wise application and selective solidification of a building material in a build area a process gas is supplied to the process chamber in a lower altitude region of the process chamber, wherein the process chamber includes a gas inlet for introducing the process gas into the process chamber and a gas outlet for discharging the process gas from the process chamber. The gas inlet and the gas outlet are provided in the lower altitude region of the process chamber and the process gas flows in a main flow from the gas inlet to the gas outlet, and wherein a secondary flow is located in a sub-region of the lower altitude region, which sub-region is located above a bottom surface of the process chamber surrounding the build area.