Nylon Salt Solution Preparation with NIR Molar Ratio Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing nylon salt solution preparation methods face challenges in achieving a consistent molar ratio of dicarboxylic acid to diamine due to errors in volumetric metering and oxidation issues, which affect molecular weight and dyeability, particularly in large-scale industrial production.
Innovation Solution
A preparation equipment and process utilizing a suspension preparation device, high-shear pump, and online near-infrared monitoring equipment to form a nylon salt solution, ensuring precise molar ratio control through continuous feeding and real-time monitoring, while minimizing oxidation risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If batch salt processes with continuous sampling and testing are used to monitor molar ratio, then measurement precision of molar ratio can be improved, but productivity and ease of operation deteriorate due to unsuitability for large-scale industrial production
Solution Approach 1:
The patent replaces manual sampling and laboratory testing (mechanical/chemical analysis methods) with near-infrared spectroscopy technology. The online near-infrared detector continuously monitors the molar ratio in real-time within the reactor system, eliminating the need for batch sampling and external testing, thus enabling both high measurement precision and large-scale continuous production
Solution Approach 2:
The patent implements a closed-loop feedback control system where the online near-infrared detector continuously measures the molar ratio, and the controller automatically adjusts the feeding rates of dicarboxylic acid and diamine based on the measured values. This real-time feedback mechanism ensures precise molar ratio control while maintaining continuous high-speed production capability
2Ease of operation
If volumetric metering methods are used for feeding dicarboxylic acid and diamine, then ease of operation is improved, but manufacturing precision of molar ratio deteriorates due to measurement errors
Solution Approach 1:
The patent replaces volumetric metering devices (which have inherent measurement errors) with mass flow meters that measure the actual mass flow rates of dicarboxylic acid and diamine. This substitution of measurement method maintains operational simplicity while dramatically improving molar ratio precision, as mass measurement is more accurate than volume measurement for these materials
Solution Approach 2:
The patent changes the measurement parameter from volume to mass for the feeding process. By using mass flow meters to measure mass flow rates and the controller to calculate molar ratios based on mass measurements rather than volume measurements, the system achieves both ease of operation and high manufacturing precision
3Ease of manufacture
If aliphatic dicarboxylic acid powder with wide particle size distribution is used, then ease of manufacture is improved, but manufacturing precision of molar ratio deteriorates due to broad range of bulk densities causing feeding errors
Solution Approach 1:
The patent replaces volumetric feeding systems (which are sensitive to bulk density variations) with mass flow meter-based feeding systems. The mass flow meters directly measure the mass flow rate of the powder, making the feeding process independent of bulk density variations caused by particle size distribution, thus maintaining ease of manufacture while achieving high feeding precision
Solution Approach 2:
The patent changes the feeding control parameter from volume-based to mass-based. By measuring and controlling the mass flow rates of dicarboxylic acid and diamine rather than their volumetric flow rates, the system eliminates the impact of bulk density variations on feeding accuracy, allowing use of readily available powder materials with wide particle size distributions
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 achieves a precise molar ratio with minimal measurement errors and reduces oxidation, enhancing the quality and consistency of the nylon salt solution for large-scale production.
Implementation Method 1
a high-shear pump, and a mixing reactor provided with a water inlet pipe, which are sequentially connected with and in communication with each other. The high-shear pump and the mixing reactor are cyclically connected with and in communication with each other through two connecting pipelines
Implementation Method 2
The second salt formation reactor further includes a circulation pipeline of the second salt formation reactor, and the circulation pipeline of the second salt formation reactor is provided with an online near-infrared monitoring equipment. The online near-infrared monitoring equipment is configured for monitoring a molar ratio of the aliphatic dicarboxylic acid to the diamine in the nylon salt solution
Implementation Method 3
The first salt formation reactor is configured for preparing a primary nylon salt solution by reacting the aliphatic dicarboxylic acid suspension with a diamine. The second salt formation reactor is configured for preparing a nylon salt solution by reacting the primary nylon salt solution with the diamine
Data Source
Figure 1
Figure 2
AI summary
A preparation equipment and a process for a nylon salt solution. The preparation equipment includes a suspension preparation device (10), a first salt formation reactor (16) and a second salt formation reactor (18). The suspension preparation device includes a feeding unit (11), a continuous feeding unit (12), a high-shear pump (13) and a mixing reactor (14), the high-shear pump (13) and the mixing reactor (14) are cyclically connected with and in communication with each other through two connecting pipelines; the second salt formation reactor (18) includes a second diamine feed pipe (181), a third diamine feed pipe (182), a circulation pipeline (184) of the second salt formation reactor and an online near-infrared monitoring equipment (185) located on the circulation pipeline (184) of the second salt formation reactor.