UV LED Photochlorination of PVC Resin
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Solution Overview
Problem
The existing photochlorination method for producing chlorinated polyvinyl chloride resin is limited by long reaction times, which hampers productivity and efficiency, despite its use of mercury lamps for chlorination.
Innovation Solution
The method involves using ultraviolet LEDs, organic ELs, or inorganic ELs to radiate ultraviolet light within specific angles (30° to 115°) relative to the stirring direction of polyvinyl chloride resin, ensuring at least 24% of the total light is directed within this range, enhancing reaction efficiency and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a mercury lamp is used for photochlorination, then the chlorination reaction can be performed, but the reaction time is long which reduces productivity
Solution Approach 1:
The patent changes the wavelength parameter of ultraviolet light from conventional mercury lamp wavelengths (254nm, 365nm) to a specific range of 280nm to 380nm with peak wavelengths of 305nm, 320nm, 340nm, 360nm, or 380nm. This parameter optimization enables more effective photochlorination reactions, significantly reducing reaction time from conventional hours to 1-6 hours while maintaining high productivity
Solution Approach 2:
The patent introduces a stirring mechanism that rotates the polyvinyl chloride resin particles during photochlorination. This dynamic movement ensures uniform exposure of resin particles to ultraviolet light and chlorine, preventing shadow effects and improving reaction efficiency. The stirring speed is controlled at 10-1000 rpm to optimize light exposure and reaction uniformity
2Productivity
If conventional photochlorination methods are used, then chlorinated polyvinyl chloride resin can be produced, but power consumption is high
Solution Approach 1:
The patent optimizes the ultraviolet light wavelength parameters to match the absorption characteristics of chlorine and polyvinyl chloride resin. By using peak wavelengths of 305nm, 320nm, 340nm, 360nm, or 380nm, the system achieves maximum photochemical reaction efficiency with minimum energy input, reducing power consumption compared to conventional mercury lamps that emit across a broader spectrum
Solution Approach 2:
The patent replaces conventional thermal or chemical chlorination methods with photochlorination using optimized ultraviolet light. This substitution eliminates the need for high-temperature heating or excessive chemical catalysts, achieving chlorination at lower energy consumption through direct photochemical activation
3Productivity
If mercury lamps are used for extended periods, then production can continue, but light source degradation occurs requiring frequent replacement
Solution Approach 1:
The patent employs ultraviolet LEDs that, while having finite lifetimes, offer significantly longer operational durability compared to conventional mercury lamps. The solid-state LED technology resists degradation from thermal cycling and mechanical shock, maintaining stable output for thousands of hours without the frequent replacements required by mercury lamps, thereby improving continuous production capability
Solution Approach 2:
The ultraviolet LED light sources are designed with integrated heat sinks and protective enclosures that actively manage thermal dissipation and protect against environmental degradation. This self-protection mechanism extends light source life and maintains consistent performance throughout the operational period
4Area of stationary object
If ultraviolet light is radiated in all directions, then complete coverage is achieved, but reaction efficiency is reduced
Solution Approach 1:
The patent positions ultraviolet LED light sources at specific locations within the reactor and directs their radiation toward regions where polyvinyl chloride resin particles are most concentrated. By optimizing the spatial distribution and directional orientation of light sources, the system achieves uniform illumination across the reaction medium without requiring omnidirectional radiation, thereby maintaining high reaction 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 significantly shortens the chlorination reaction time, maintains mechanical strength and heat resistance comparable to conventional methods, and reduces production costs by minimizing light source degradation and replacement needs.
Implementation Method 1
ultraviolet radiation using a mercury lamp is usually performed in order to generate chlorine radicals
Implementation Method 2
the radiation of the ultraviolet light is performed by using at least one light source selected from the group consisting of an ultraviolet LED, an organic EL and an inorganic EL
Implementation Method 3
polyvinyl chloride resin is chlorinated by radiating ultraviolet light in a reactor into which polyvinyl chloride resin and chlorine have been introduced
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
The present invention relates to a method for producing chlorinated polyvinyl chloride resin in which polyvinyl chloride resin is chlorinated by radiating ultraviolet light in a reactor into which polyvinyl chloride resin and chlorine have been introduced, wherein the radiation of the ultraviolet light is performed by using at least one light source selected from the group consisting of an ultraviolet LED, an organic EL and an inorganic EL, the light source is disposed within the reactor, at least one radiation direction of the ultraviolet light is within a range of 30° or more and 115° or less with respect to a stirring direction of polyvinyl chloride resin, and an amount of ultraviolet light radiated within the range of 30° or more and 115° or less with respect to the stirring direction of polyvinyl chloride resin is 24% or more based on a total amount of ultraviolet light radiated from the light source taken as 100%. It is thereby possible to provide a method for producing chlorinated polyvinyl chloride resin in which the reaction efficiency of the chlorination reaction is higher than a conventional method of photochlorination using a mercury lamp, and that produces chlorinated polyvinyl chloride resin having the same levels of mechanical strength and heat resistance as the chlorinated polyvinyl chloride resin produced by the conventional method.