Two-Stage PET Flake Washing for Heavy Contamination Removal
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Solution Overview
Problem
Existing methods for washing PET flakes from municipal PET bottles are insufficient for heavily contaminated commercial PET bottles, leading to inadequate removal of foreign matters.
Innovation Solution
A two-stage washing process involving a batch washing tank followed by a continuous washing tank, utilizing a turbo washer and multiple dehydrators, with separate circulation paths for the washing solutions, to enhance the washing performance and ensure thorough cleaning of PET flakes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single washing method is used for PET flakes, then the washing process is simple, but it cannot sufficiently remove foreign matters from heavily contaminated commercial PET bottles
Solution Approach 1:
The washing process is divided into two distinct segments: a batch washing tank for initial washing and a continuous washing tank for subsequent washing. This segmentation allows each tank to be optimized for its specific function, with the batch tank handling initial contamination removal and the continuous tank providing thorough cleaning, thereby resolving the contradiction between washing quality and process complexity.
Solution Approach 2:
The batch washing tank performs preliminary washing of PET flakes before they enter the continuous washing tank. This preliminary action removes a significant portion of foreign matters and contaminants, reducing the burden on the subsequent continuous washing process and enabling achieving high washing quality without excessive overall process complexity.
2Manufacturing precision
If a batch washing tank is used alone, then the washing process is simple to operate, but it cannot achieve sufficient washing for heavily contaminated PET flakes
Solution Approach 1:
The washing system is segmented into a batch washing tank (easy to operate) and a continuous washing tank (provides thorough cleaning). The batch tank maintains operational simplicity while the continuous tank, positioned downstream, enhances washing quality through continuous flow and prolonged washing action, thus resolving the contradiction between ease of operation and washing quality.
Solution Approach 2:
The batch washing tank acts as an intermediary between the initial state of heavily contaminated PET flakes and the final washing requirement. It performs the first stage of cleaning, reducing contamination levels, and then transfers partially washed flakes to the continuous washing tank for final thorough cleaning, thereby achieving high washing quality while maintaining operational simplicity in the first stage.
3Productivity
If a continuous washing tank is used alone, then washing efficiency is improved, but it cannot effectively handle the variability in contamination levels from different PET bottle sources
Solution Approach 1:
The washing system is segmented such that the batch washing tank handles the variability in contamination levels from different PET bottle sources (municipal vs. commercial), while the continuous washing tank provides efficient continuous processing. This segmentation allows the batch tank to adapt to varying contamination severity and the continuous tank to maintain high productivity, resolving the contradiction between productivity and adaptability.
Solution Approach 2:
The batch washing tank performs preliminary washing that adapts to the specific contamination level of the input material, whether from municipal or commercial bottles. This preliminary adaptation reduces contamination variability before the flakes enter the continuous washing tank, enabling the continuous process to operate efficiently regardless of the original contamination severity, thus resolving the contradiction between productivity and adaptability.
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 cleans PET flakes from both municipal and commercial sources, ensuring high-quality recycled PET flakes by improving washing efficiency and reducing contamination.
Implementation Method 1
a first stirrer for stirring the washing solution and the washing targets in the first container
Implementation Method 2
a second stirrer for stirring the washing targets and the washing solution in the washing flow path
Implementation Method 3
a first dehydrator between the extraction tank and the turbo washer, and a second dehydrator positioned further downstream than the receiving tank
Data Source
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AI summary
An object of the present disclosure is to provide a PET flake washing apparatus and a PET flake washing method capable of obtaining sufficiently washed recycled PET flakes under conditions where PET flakes obtained from commercial PET bottles are included, and even under conditions where only PET flakes obtained from commercial PET bottles are used. A PET flake washing apparatus 100 according to the present disclosure includes: a batch washing tank 6 including a first feeding part 1 for feeding a washing solution and crushed PET flakes as washing targets 50, a first container 2, a first stirrer 3, a first discharge port 4, and an opening and closing tool 5 for the first discharge port; a supply device 7 positioned further downstream than the batch washing tank and supplying a predetermined portion of the washing targets washed in the batch washing tank per unit time; and a continuous washing tank 12 including a second feeding part 8 into which a washing solution and washing targets are fed, a second discharge port 9, a washing flow path 10 connecting the second feeding part and the second discharge port, and a second stirrer 11.