Inclined Polymer Transfer Lines for Loop Reactor Drainage
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Solution Overview
Problem
The existing polymerization plants face challenges in completely emptying and cleaning the transfer pipes between loop reactors during emergency stops, leading to prolonged downtime, increased costs, and reduced productivity due to polymer agglomerations.
Innovation Solution
The apparatus features a connection line with pipes sloped at an angle greater than the polymer's angle of rest, equipped with an on-off valve at the higher end, allowing for automatic drainage of polymer slurry back to the first loop reactor during shutdowns, preventing reflow and facilitating quick cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If horizontal transfer lines are used to connect loop reactors, then the plant layout is simplified and installation is easier, but polymer slurry accumulates in the transfer lines during emergency stops causing obstructions and prolonged downtime
Solution Approach 1:
Instead of using horizontal transfer lines that facilitate installation but cause slurry accumulation, the patent inverts the approach by using inclined transfer lines with slopes greater than the polymer's angle of rest. This inversion prioritizes easy drainage and obstruction prevention over installation convenience, allowing slurry to drain back to the first loop reactor during emergency stops.
Solution Approach 2:
The transfer lines are designed to automatically drain polymer slurry back to the first loop reactor using gravity alone, without requiring external pumping or manual intervention during emergency stops. The inclination angle exceeds the polymer's angle of rest, ensuring self-drainage and preventing obstructions.
2Productivity
If polymer slurry is transferred between loop reactors during normal operation, then continuous polymerization is maintained, but during emergency stops the slurry cannot be emptied from transfer lines leading to polymer agglomerations and costly cleaning operations
Solution Approach 1:
The transfer lines are pre-designed with inclination angles greater than the polymer's angle of rest before any emergency stop occurs. This preliminary design ensures that when an emergency stop happens, the slurry can immediately drain back to the first loop reactor without requiring any additional action or equipment, preventing obstructions and maintaining system reliability.
3Device complexity
If the transfer line is positioned horizontally, then equipment arrangement is simplified, but complete emptying of the transfer line during shutdowns becomes difficult requiring manual cleaning
Solution Approach 1:
The patent transitions from a horizontal (2D plane) transfer line arrangement to an inclined (3D spatial) arrangement. By introducing a vertical dimension through inclination angles greater than the polymer's angle of rest, the system enables complete drainage of polymer slurry back to the first loop reactor, making cleaning unnecessary and significantly improving ease of maintenance.
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 arrangement ensures the transfer line can be quickly emptied, reducing the risk of obstructions and minimizing downtime, thus avoiding costly cleaning operations and maintaining plant productivity.
Implementation Method 1
one or more adjacent pipes arranged at progressively increasing heights, each pipe forming with a horizontal direction (x) an angle α greater than the angle of rest of the obtained polymer
Data Source
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AI summary
An apparatus for the liquid-phase polymerization of one or more a-olefins comprising: a first reactor selected from a loop reactor or a continuously stirred tank reactor; at least a downstream loop reactor; a connection line for transferring a polymer slurry from said first reactor to said downstream loop reactor, said connection line comprising: one or more adjacent pipes arranged at progressively increasing heights, each pipe forming with a horizontal direction (x) an angle a greater than the angle of rest of the obtained polymer; an on-off valve positioned flush with the wall of said downstream loop reactor.