Ethylene Slurry Reactor Baffle Positioning to Prevent Pump Blockages
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Solution Overview
Problem
Continuous stirred tank reactors in ethylene slurry polymerization systems face operational interruptions due to slurry pump blockages caused by polymer lumps accumulating on reactor baffles and inner walls, leading to reduced flow and frequent cleaning needs.
Innovation Solution
The process involves maintaining the reactor liquid level above the baffle top and cooled slurry discharge point, preventing polymer deposition on baffles and mechanical supports, and using a reactor baffle system with strategically positioned baffles to minimize fouling and splashing, thereby reducing the formation of polymer lumps that could block the slurry pumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooled slurry is discharged into the vapor space above the liquid level in the reactor, then heat exchange efficiency is improved, but polymer deposition on baffles and reactor walls occurs causing pump blockages
Solution Approach 1:
The baffle top is positioned below the liquid level before slurry discharge occurs, preventing polymer deposition on baffles and mechanical supports in advance. This preliminary positioning of the baffle eliminates the condition that leads to pump blockages while maintaining effective heat exchange through the cooled slurry discharge system
2Temperature
If slurry is discharged above the liquid level for cooling, then cooling efficiency is improved, but polymer lumps form and block the slurry pump inlet
Solution Approach 1:
The baffle structure is pre-positioned with its top below the liquid level to prevent polymer deposition before it occurs. This preliminary protective measure stops the formation of polymer lumps that would otherwise block the pump inlet and reduce productivity
Solution Approach 2:
The baffle acts as an intermediary structure that intercepts and contains the discharged slurry within the liquid phase zone, preventing direct contact between the discharged slurry and the vapor space where polymer deposition would occur on pump inlet surfaces
3Reliability
If the reactor liquid level is maintained above the baffle top, then polymer deposition is prevented, but the discharge of cooled slurry may be restricted
Solution Approach 1:
The baffle is positioned at a specific location below the liquid level to create a localized zone that prevents polymer deposition on critical surfaces. This localized quality change allows the rest of the reactor to maintain normal slurry circulation and discharge flow rates
Solution Approach 2:
The baffle structure is pre-positioned to prevent polymer deposition before it can occur during slurry discharge operations, ensuring reliable pump operation without restricting overall slurry flow through the reactor system
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 reduces slurry pump blockages, ensuring consistent operation by preventing polymer accumulation on reactor components and maintaining smooth slurry flow, thereby enhancing the overall performance and reliability of the ethylene slurry polymerization process.
Implementation Method 1
maintaining the reactor liquid level above the baffle top and cooled slurry discharge point
Implementation Method 2
an agitator for mixing the contents of the internal reactor volume
Implementation Method 3
a reactor outlet for feeding a reactor slurry to a cooler
Data Source
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AI summary
A slurry polymerization process comprising polymerizing monomers in a reactor comprising baffles, a first slurry feed line for returning cooled slurry from a cooler and optionally a second slurry feed line for transferring reactor slurry from a previous reactor of a cascade of polymerization reactors, wherein the baffle top, the first slurry feed line discharge end and the second slurry feed line end are located below the reactor liquid level.