Mass Transfer Tray Circulation to Prevent Monomer Polymerization
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Solution Overview
Problem
Existing thermal separation columns face issues with unwanted polymerization of (meth)acrylic monomers, leading to polymer formation in dead zones within the mass transfer trays, which can block passage orifices and pose an explosion risk due to exothermic polymerization.
Innovation Solution
A column with a circulation device featuring a drain orifice and recycling orifice is used to generate liquid circulation on the mass transfer tray, reducing residence time and preventing dead zones, thereby preventing polymer formation and reducing the risk of explosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If liquid is allowed to collect on the mass transfer tray during thermal separation, then heat and mass transfer efficiency is improved, but polymerization occurs in dead zones leading to passage orifice blockage
Solution Approach 1:
The circulation device continuously pumps liquid from the collecting area back onto the mass transfer tray, ensuring continuous liquid movement and preventing stagnant dead zones where polymerization could occur. This continuous circulation maintains both heat transfer efficiency and prevents polymer occlusion.
Solution Approach 2:
The circulation device extracts liquid from the collecting area and redistributes it, removing the harmful stagnation effect while preserving the beneficial heat and mass transfer function. By taking out the stationary liquid and replacing it with circulating liquid, the system eliminates polymerization risks.
2Productivity
If liquid residence time on the mass transfer tray is extended, then thermal separation efficiency is improved, but polymerization risk increases due to exothermic reaction
Solution Approach 1:
The circulation device creates periodic liquid movement patterns, continuously removing liquid from and returning it to the mass transfer tray. This periodic action prevents extended residence time in any single location, thereby preventing the accumulation of heat from exothermic polymerization while maintaining thermal separation efficiency.
Solution Approach 2:
The circulation device creates a feedback loop where liquid is continuously monitored and redistributed. This feedback mechanism ensures that liquid does not remain stationary long enough to polymerize, while still allowing sufficient contact time for efficient thermal separation to occur.
3Reliability
If a circulation device is added to prevent polymerization, then operational safety is improved, but device complexity increases
Solution Approach 1:
The circulation device is designed to be self-regulating, using the liquid's own weight and the pump's continuous operation to maintain circulation without requiring complex external control systems. This self-service approach enhances safety while minimizing the increase in device complexity.
Solution Approach 2:
The circulation device serves multiple functions simultaneously: it prevents polymerization by maintaining liquid movement, enhances heat transfer efficiency through continuous circulation, and can be integrated into existing column structures. This multi-functionality justifies the added complexity by providing multiple benefits from a single device addition.
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 circulation device effectively prevents polymer occlusion of passage orifices and reduces the risk of explosions by ensuring uniform liquid distribution and reducing residence time on the mass transfer tray, enhancing the operational stability and safety of the thermal separation process.
Implementation Method 1
A column with a circulation device featuring a drain orifice and recycling orifice is used to generate liquid circulation on the mass transfer tray
Implementation Method 2
reducing residence time and preventing dead zones, thereby preventing polymer formation
Implementation Method 3
ensuring uniform liquid distribution and reducing residence time on the mass transfer tray
Data Source
AI summary
The present disclosure includes a column (1) having a cylindrical, vertical column body (2) forming a column cavity (3), and a mass transfer tray (4) disposed in the column cavity (3) and forming a collecting area (5). The column (1) is characterized by a circulation device (9) having at least one drain orifice (10) formed in the column body (2) above the collecting area (5), a circulation line (11) in fluid connection with the drain orifice (10) and at least one recycling orifice (14; 14-1 to 14-3) which is in fluid connection with the circulation line (11) and is formed in the column body (2) above the collecting area (5). Also disclosed herein is a thermal separating process in which a gas ascends within a column (1) of the present disclosure, and a liquid descends within the column (1), said gas and/or liquid containing (meth)acrylic monomers.