Liquid-Solid Sampling System for Loop Slurry Reactors

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Solution Overview

Problem

Existing methods for rapid and frequent sampling of liquid streams in liquid-solid mixtures, such as centrifugation and sieving, result in excessive waste and are inefficient, necessitating a more effective separation technique that minimizes waste generation.

Innovation Solution

A method involving the withdrawal of a liquid-solid mixture from a vessel, flowing it through a vertical settling tube to separate solids from liquids, removing a small fraction of the liquid for analysis, and returning the unused mixture, which includes a system with inlet and outlet valves, a sample valve, and a controller to manage the flow and sampling process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If centrifugation or sieving is used to separate liquid from liquid-solid mixture, then separation speed is improved, but waste generation increases

Engineering Contradiction:
Improveseparation speedVSAvoidwaste generation
Core Design Contradiction:
SpeedVSLoss of substance

Solution Approach 1:

The patent changes the separation parameter from mechanical force (centrifugation) or filtration (sieving) to gravitational settling. By allowing the mixture to stand undisturbed, solids naturally settle to the bottom due to gravity, enabling liquid withdrawal from the top without mechanical separation equipment, thus minimizing waste while achieving separation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts only the liquid portion needed for analysis from the liquid-solid mixture by withdrawing it from the top layer after settling. This selective extraction allows rapid sampling with minimal waste, as only the required liquid fraction is removed while the settled mixture can be reused or processed further.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If centrifugation or sieving is used for liquid-solid separation, then separation effectiveness is improved, but device complexity increases

Engineering Contradiction:
Improveseparation effectivenessVSAvoidequipment complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a self-service approach where the liquid-solid mixture automatically separates itself through gravitational settling without requiring external mechanical intervention. The system uses the natural density difference between liquid and solid phases to achieve separation, eliminating the need for complex centrifuges or sieving equipment while maintaining reliable separation effectiveness.

Inventive Principle:
Principle #25Self-service

3Quantity of substance

If traditional separation techniques are used, then liquid can be obtained for analysis, but sampling frequency is reduced due to waste constraints

Engineering Contradiction:
Improveliquid sample obtainedVSAvoidsampling frequency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent implements periodic sampling by allowing the liquid-solid mixture to settle, withdrawing the liquid phase at intervals, and returning the settled mixture to the process stream. This periodic action enables frequent sampling without depleting the system, as the mixture is restored after each sampling event, thereby increasing sampling frequency while maintaining adequate liquid quantity for analysis.

Inventive Principle:
Principle #19Periodic action

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 allows for quick and effective liquid-solid separation without centrifugation or sieving, reducing waste and enabling more frequent sampling, thereby improving the timeliness and consistency of data for polymerization process control.

Implementation Method 1

periodically stopping the flow of the sample of the liquid-solid mixture in the tube for a time period sufficient for the solid to settle to a bottom portion of the tube and for the liquid to occupy an upper portion of the tube

Methodology Applied
Scientific EffectGravitational settling: Sedimentation

Data Source

PatentEP3300503B1Liquid-solid sampling system for a loop slurry reactor
Publication Date: 2020.12.30 CHEVRON PHILLIPS CHEMICAL COMPANY LP
  • EP3300503B1 patent drawingFigure 1~2

AI summary

Polymerization reactor systems providing integrated liquid-solid sampling systems are disclosed. Methods for operating such polymerization reactor systems and for measuring a property of the liquid portion of liquid-solid mixture are described.