Polyamide Granulation Liquid Recycle for Extraction Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The production of polyamide 6 granules is hindered by excessive lactam and oligomer concentrations in the cutting water, leading to foam formation, filter clogging, and quality fluctuations, which necessitate the continuous addition of demineralized water, increasing energy consumption and potentially resulting in suboptimal granule quality.
Innovation Solution
Part of the granulation liquid is fed into the extraction liquid stream at multiple points in the extraction column to adjust temperature and lactam concentration, allowing for a higher inlet temperature and reduced lactam concentration, thereby enhancing extraction performance and efficiency without the need for additional cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If demineralized water is continuously added to cutting water to maintain lactam concentration, then granulation quality is maintained, but energy consumption increases due to additional evaporation processing
Solution Approach 1:
The invention combines the granulation liquid circuit and extraction liquid circuit by feeding part of the granulation liquid into the extraction liquid stream. This merging allows the granulation liquid to serve dual purposes: cooling the extraction liquid and providing lactam for extraction, thereby eliminating the need for separate demineralized water addition and reducing evaporation energy consumption.
Solution Approach 2:
The granulation liquid is given multiple functions: it cools the extraction liquid, maintains the lactam concentration in the extraction stream, and serves as extraction liquid. This multi-functionality eliminates the need for separate cooling and concentration control systems, reducing overall energy consumption while maintaining granulation quality.
2Productivity
If cutting water temperature is increased to improve granulation efficiency, then granulation performance improves, but lactam concentration in cutting water increases leading to foaming and filter clogging
Solution Approach 1:
The invention extracts the harmful concentrated cutting water from the granulation circuit by feeding it into the extraction column. The extraction process removes lactam and oligomers from the granulation liquid, preventing foaming and filter clogging while allowing the granulation process to operate at higher temperatures for improved efficiency.
Solution Approach 2:
The invention converts the harmful concentrated cutting water (which causes foaming and clogging) into a beneficial extraction liquid. By feeding the concentrated cutting water into the extraction column, the lactam and oligomers are recovered and reused, transforming a waste stream into a valuable resource for the extraction process.
3Productivity
If extraction liquid temperature is increased to improve extraction performance, then extraction efficiency improves, but additional cooling equipment and energy are required
Solution Approach 1:
The invention merges the cooling function with the extraction liquid feed. The granulation liquid, which is at a lower temperature, is fed into the extraction column to cool the extraction liquid in-situ. This eliminates the need for separate cooling equipment while maintaining high extraction efficiency through optimal temperature gradients.
Solution Approach 2:
The extraction system cools itself by utilizing the cooler granulation liquid as the cooling medium. The granulation liquid absorbs heat from the extraction liquid as it flows through the extraction column, providing self-cooling without external cooling equipment and maintaining energy efficiency.
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
This approach increases extraction performance, reduces the volume of the extraction column, and maintains efficient operation by maintaining a favorable concentration gradient, thus avoiding the need for additional cooling and optimizing energy use.
Implementation Method 1
Part of the granulation liquid is fed into the extraction liquid stream at several feed points in the extraction column to adjust temperature and lactam concentration
Implementation Method 2
the subsequent extraction of monomeric and oligomeric components from the PA granules in an extraction column
Implementation Method 3
The concentrated cutting water stream is fed into the evaporation unit, wherein the stream is heated in order to concentrate and/or separate the lactam
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a method for producing polyamides, the flow management of the process being rendered more efficient. The method is based on the polymerization of lactam to a polyamide-containing polymer melt, the subsequent granulation of the polymer melt to polyamide granules using a granulation liquid, and the subsequent extraction of monomer and oligomer components from the PA granules in an extraction column. The invention further relates to a device for carrying out the method.