Polysilicon Packaging Clamping and Sieving
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Solution Overview
Problem
Existing automatic packaging systems for polycrystalline silicon fragments often result in contamination and high levels of fines, leading to increased downtimes, contamination, and additional work for customers due to the sharp-edged, non-free-flowing nature of the material and inefficiencies in filling and sealing processes.
Innovation Solution
A method involving a dosing system with a conveying chute and separate dosing channels for coarse and fine fragments, using sieves to separate fines before filling, and a clamping device to control the drop height and ensure precise filling into plastic bags, minimizing contamination and fines production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If conventional packaging machines are used to package polysilicon fragments, then packaging automation is achieved, but the sharp-edged fragments puncture plastic bags causing contamination and machine downtime
Solution Approach 1:
The patent applies preliminary action by rounding the edges of polysilicon fragments through controlled crushing and classification before packaging. The fragments are processed through a classification device that separates them by size and shape, ensuring only fragments with rounded edges suitable for safe packaging are used. This preliminary modification of the material properties prevents bag puncturing during automated packaging operations.
2Productivity
If automatic filling systems are used for polysilicon packaging, then productivity increases, but fines content increases to unacceptable levels
Solution Approach 1:
The patent applies preliminary action by implementing a classification device that pre-sorts polysilicon fragments by size and shape before the filling process. This classification step removes fine particles and ensures only uniformly sized fragments with rounded edges are fed into the filling system, preventing fines generation during packaging while maintaining high productivity.
Solution Approach 2:
The patent applies feedback by using a weighing device that continuously monitors the weight of polysilicon being filled into each bag. The system provides real-time feedback to control the filling process, adjusting the feed rate to maintain target weight accuracy and prevent overfilling or undersfilling, thereby ensuring packaging precision while operating at high speed.
3Manufacturing precision
If manual packaging methods are used, then fines content is reduced, but personnel costs and operational complexity increase
Solution Approach 1:
The patent applies preliminary action by preparing polysilicon fragments in advance through controlled crushing and classification to ensure they have the correct size distribution and rounded edges. This pre-processing enables automatic packaging systems to operate with manual-level precision regarding fines content, eliminating the need for complex manual handling procedures while maintaining low contamination levels.
4Productivity
If polysilicon fragments are dumped directly into bags, then filling speed increases, but contamination from bag contact materials increases
Solution Approach 1:
The patent applies the intermediary principle by introducing a conveyor system with a protective coating as a mediator between the polysilicon fragments and the packaging environment. The conveyor belt is coated with a material that prevents direct contact between the silicon fragments and the conveyor surface, thereby preventing contamination during the high-speed filling process while maintaining efficient material transport.
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
Significantly reduces fines content to less than 1400 ppmw for fragment sizes 20-60 mm, improving packaging efficiency and reducing contamination, while maintaining a low level of personnel effort and operational costs.
Implementation Method 1
a clamping device which acts on the plastic bag in such a way that it is laterally compressed at a specific point by a clamp, so that its cross section is reduced there
Implementation Method 2
separating mechanisms for screening off fines are attached
Data Source
AI summary
The method involves supplying polycrystalline silicon in a metering system. The polycrystalline silicon transferred from the metering system is separated into fine fractions by sieving, and filling into a synthetic bag arranged under the metering system. The weight of synthetic bag filled with the polycrystalline silicon is determined. The filling operation is terminated after reaching a target weight of synthetic bag. The height of the polycrystalline silicon filled in synthetic bag is set to less than 450 mm by a clamping device during entire filling operation. An independent claim is included for a clamping device for packing polycrystalline silicon in synthetic bag.