Slurry Loop Polymerization Catalyst Inlet Design
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Solution Overview
Problem
In slurry loop polymerization reactors, the protrusion of catalyst injection nozzles into the reaction zone leads to fouling and non-uniform flow, which increases with larger reactor sizes, affecting the polymerization process.
Innovation Solution
The catalyst inlet pipe is designed to protrude no more than 1/10th of the reactor diameter into the reaction zone, with a minimal internal diameter and optimized linear velocity to minimize fouling and ensure even dispersion of the catalyst.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the catalyst injection nozzle protrudes into the reaction zone to ensure central injection and rapid dispersion, then the catalyst is quickly dispersed into the reaction mixture, but the protrusion causes fouling and non-uniform flow, especially in larger reactors
Solution Approach 1:
The harmful protruding part (injection nozzle) is extracted and replaced by introducing catalyst through the wall of the reaction zone. This removes the source of fouling while maintaining the function of catalyst introduction and dispersion through optimized injection geometry into the flowing slurry.
Solution Approach 2:
A diluent stream is introduced as an intermediary to carry the catalyst into the reaction zone without direct contact between the injection system and the reactive slurry. This mediator prevents fouling while ensuring proper catalyst distribution through the combined flow of diluent and slurry.
2Productivity
If the reactor size is increased to meet production demands, then the productivity increases, but the propensity for fouling of the injection nozzles increases
Solution Approach 1:
By removing the protruding injection nozzle from the reaction zone entirely and introducing catalyst through the wall, the invention eliminates the fouling problem that scales with reactor size, allowing continuous operation in large reactors without the fouling limitations that would otherwise restrict productivity.
3Object-affected harmful factors
If the injection nozzle is designed with multiple conduits and shielding to prevent fouling, then the fouling at the tip is reduced, but the complexity of the injection device increases
Solution Approach 1:
Instead of adding complexity to the injection nozzle with multiple conduits and shielding structures, the invention extracts and removes the problematic protruding nozzle entirely, replacing it with a simpler wall-introduction system that achieves fouling prevention through geometric design rather than complex structures.
4Manufacturing precision
If the injection nozzle protrudes into the reaction zone to ensure central injection, then the catalyst is introduced into the center of the flow, but the protrusion creates flow non-uniformity and deposition
Solution Approach 1:
The protruding injection nozzle that causes flow disruption is extracted and replaced by a wall-introduction system. The injection geometry is designed to deliver catalyst to the central flow region without physical protrusion, maintaining precise catalyst positioning while preserving flow uniformity and preventing deposition.
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 design minimizes fouling and maintains uniform flow, allowing for high space-time yields and high monomer concentrations without significant fouling risks, even in larger reactors.
Implementation Method 1
the catalyst, which is relatively concentrated at its point of injection, is quickly dispersed away from the tip of the injection nozzle
Implementation Method 2
Slurry loop reaction zones are in the form of continuous loop in which polymerisation occurs in the circulating slurry
Data Source
Figure 1~2
Figure 3
AI summary
The present invention relates to a process for polymerisation in a slurry loop polymerisation reactor, which reactor comprises: a) a reaction zone in the form of a slurry loop, b) at least one feed inlet for monomers, diluent and optionally comonomers, c) at least one catalyst inlet for polymerisation catalyst, and d) at least one discharge conduit for removal of polymer, and which process comprises passing monomer, diluent and catalyst, and optionally comonomer, into the reaction zone through their respective inlets, wherein they react to form a slurry of polymer solids, and wherein the at least one catalyst inlet is in the form of an inlet pipe and no part of the inlet pipe protrudes beyond the wall of the reaction zone and into the reaction zone by more than 1/10th of the diameter of the reaction zone at the point where the inlet pipe joins the reaction zone.