Injection Nozzle Design for Fluidized Bed Erosion Control
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Solution Overview
Problem
Gas distribution devices in fluidized bed processes, such as those used in the FCC process, face significant erosive wear issues due to the high velocity and pressure of gas and solid particles, leading to frequent repairs and maintenance challenges.
Innovation Solution
The design of injection nozzles with multiple fluid pathways parallel, perpendicular, or transverse to the nozzle axis, which creates a stable and uniform gas velocity profile, reducing the risk of erosion by minimizing high-velocity jets and negative axial velocities, thereby extending the lifespan of the nozzles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gas is injected at high velocity to prevent solids backflow into the nozzle, then solids backflow is prevented, but erosion of the injection nozzle increases
Solution Approach 1:
The patent changes the velocity profile parameters by creating a stable, uniform distribution that eliminates negative axial velocities and excessive jet velocities. This is achieved through multiple fluid pathways with specific geometric configurations that transform the gas flow characteristics, maintaining sufficient velocity to prevent solids backflow while avoiding the excessive velocities that cause erosion.
Solution Approach 2:
The patent applies different flow characteristics to different regions of the nozzle by creating multiple fluid pathways with varying orientations (parallel, perpendicular, transverse to the nozzle axis). Each pathway is designed to deliver gas at appropriate local velocities, ensuring uniform distribution while preventing both solids backflow and excessive erosion at any single location.
2Stability of the object's composition
If uniform gas distribution is achieved through pressure drop across injection nozzles, then gas distribution uniformity is improved, but the complexity of the distribution system increases
Solution Approach 1:
The patent segments the gas distribution function into multiple fluid pathways within the nozzle structure itself. By dividing the gas flow into multiple streams that travel through different orientations (parallel, perpendicular, transverse pathways), the system achieves uniform distribution across the bed cross-section while keeping the overall device structure relatively simple and integrated.
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 proposed nozzle design results in reduced erosion, decreased catalyst attrition, and improved gas distribution, leading to longer maintenance intervals and increased operational efficiency.
Implementation Method 1
The fluid inlet may include multiple fluid pathways parallel, perpendicular, or transverse to the nozzle axis... creates a stable and uniform gas velocity profile... minimizing high-velocity jets and negative axial velocities
Data Source
Figure 1A~1B
Figure 1C~1H
Figure 2A~5B
AI summary
Injection nozzles for use in a gas distribution device are disclosed. In one aspect, the injection nozzle may include: a tube having a fluid inlet and a fluid outlet; wherein the inlet comprises a plurality of flow restriction orifices. In another aspect, embodiments disclosed herein relate to an injection nozzle for use in a gas distribution device, the injection nozzle including: a tube having a fluid inlet and a fluid outlet; wherein the fluid inlet comprises an annular orifice surrounding a flow restriction device. Injection nozzles according to embodiments disclosed herein may be disposed in a gas distribution manifold used in a vessel, for example, for conducting polymerization reactions, spent catalyst regeneration, and coal gasification, among others.