Annular Injector Structure for LDPE Mixing Without Back Mixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing reactor systems face issues with back mixing and material build-up/fouling during the injection and mixing of reactive fluids in turbulent process flows, leading to unbalanced reaction profiles and gel-like by-products in ethylene polymer production.
Innovation Solution
A device with a cylindrically shaped injector part and a downstream-facing nozzle, integrated into an annular part with a fin-shaped support structure made from a single piece of metal, which minimizes asymmetrical turbulence and reduces back mixing by streamlining the fluid flow and preventing fouling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional injector nozzle is used to introduce reactive fluid into the reaction vessel, then the reactive fluid can be injected into the process flow, but back mixing occurs and material build-up/fouling happens on the injector surfaces
Solution Approach 1:
The injector nozzle is designed with a cylindrical shape and rounded edges instead of sharp corners. This curvature prevents fluid separation and reduces areas where material can accumulate and foul the surfaces, directly addressing the material build-up problem while maintaining injection efficiency
Solution Approach 2:
The nozzle is positioned asymmetrically at an offset from the central axis of the annular part, and the supply channel is configured to deliver fluid in a direction that creates asymmetrical flow patterns. This asymmetry prevents symmetrical back-mixing zones and reduces fouling on injector surfaces
2Stability of the object's composition
If the reactive fluid is injected at high pressure to maintain balanced reaction profile, then the reaction uniformity is improved, but asymmetrical turbulence increases causing unbalanced reaction zones
Solution Approach 1:
The cylindrical injector part with rounded edges creates localized flow characteristics that differ from the bulk flow. This local quality control ensures that the injection zone maintains stability and uniformity without creating large-scale asymmetrical turbulence that would disrupt overall reaction balance
Solution Approach 2:
The curved cylindrical surfaces of the injector guide the high-pressure fluid flow smoothly, preventing sharp eddies and asymmetrical turbulence. The rounded geometry distributes the high-pressure injection more evenly, maintaining reaction uniformity while reducing flow distortion
3Ease of manufacture
If the injector structure is made from multiple components for ease of assembly, then manufacturing and maintenance become easier, but mechanical integrity and sealing performance deteriorate under high pressure
Solution Approach 1:
The support structure and injector nozzle are merged into a single integrated component. This eliminates the interfaces between separate parts that would create potential leakage paths, ensuring reliable sealing under high pressure while maintaining ease of assembly as a single unit
Solution Approach 2:
The integrated support structure and injector assembly serves multiple functions: structural support, fluid distribution, and sealing. This multi-functionality reduces the number of separate components needed, simplifying assembly while maintaining high pressure integrity through the unified design
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 device ensures even distribution and reduced back mixing of the reactive fluid, preventing material build-up and fouling, thus enhancing the production of ethylene polymers by maintaining a balanced reaction profile and improving mechanical integrity in high-pressure environments.
Implementation Method 1
The device ensures even distribution and reduced back mixing of the reactive fluid, preventing material build-up and fouling
Data Source
AI summary
The invention relates to a device (100) for injecting and mixing a reactive fluid in a flow of a process fluid for the preparation of polyolefins, comprising: •an annular part (101) having an outer wall and an inner wall (102), wherein the annular part (101) is arranged for having a flow of the process fluid in a transport direction (F); •a support structure (103) connected to the inner wall (102) of the annular part (101); •an injector part (104) mounted on the support structure (103), wherein the injector part (104) is cylindrically shaped and wherein the cylindrical axis A-A′ of the injector part is parallel with a central axis of the annular part and is in the central part of the annular part (101); wherein the injector part (104) comprises a nozzle (105) for injecting the reactive fluid, disposed at a downstream side of the injector part relative to the transport direction (F); •a supply channel (106) extending from the outer wall of the annular part (101) through the support structure (103) to the nozzle (105) of the injector part (104), and wherein the annular part (101), the support structure (103) and the injector part (104) are made from a single piece of metal.