Fluid Solids Contacting Device Grid Assembly for Bubble Breaking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In fluid bed systems operating at low superficial velocities, gas voidages such as bubbles form, reducing contact between the gas and solid phases, which is exacerbated by the need for internals like subway grating to prevent flooding and ensure adequate contact, requiring precise control of open area and gas velocities, and a unique mechanical design to withstand high temperatures and forces.
Innovation Solution
A fluid solids contacting device comprising a vessel with a grid assembly section of horizontal chords and grid platforms, supported by chairs, designed to withstand fluidized forces and prevent bubble formation, allowing for controlled gas and solid interaction while maintaining structural integrity under high temperatures and pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If internals such as subway grating are used to break bubbles and prevent flooding, then gas-solid contacting is improved, but the open area is reduced and gas velocity control becomes more restrictive
Solution Approach 1:
The internal structure is segmented into multiple horizontal chords with grid platforms positioned between them, creating multiple levels of bubble-breaking surfaces. This segmentation allows the gas flow to be divided and redirected multiple times, improving gas-solid contacting efficiency while maintaining adequate open area for gas passage.
Solution Approach 2:
The internal structure extends in the radial direction with horizontal chords positioned at different heights, creating a three-dimensional arrangement. This dimensional approach allows bubble breaking to occur throughout the vessel height rather than at a single plane, improving contacting efficiency without significantly reducing the cross-sectional open area.
2Reliability
If internals are added to break bubbles and prevent flooding, then gas-solid contacting is improved, but the device complexity increases
Solution Approach 1:
The horizontal chords and grid platforms serve multiple functions simultaneously: they break bubbles, prevent flooding, provide structural support for the internal assembly, and define the flow paths. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.
Solution Approach 2:
The support structure and the bubble-breaking structure are merged into a single integrated internal assembly. The horizontal chords that provide structural support also serve as the bubble-breaking surfaces, eliminating the need for separate support frameworks and reducing overall structural complexity.
3Strength
If the structural member is designed to withstand fluidized forces at high temperatures, then mechanical strength is improved, but the manufacturing difficulty increases
Solution Approach 1:
The structural members are designed with specific geometric parameters (I-beam or inverted T-beam cross-sections, predetermined spacing) that optimize their strength-to-weight ratio for withstanding fluidized forces at high temperatures. These standardized parameter choices simplify manufacturing while ensuring adequate mechanical strength.
Solution Approach 2:
The structural members have enhanced strength properties localized at critical regions (flanges and web connections in I-beams) where fluidized forces are most intense, while other portions can be lighter. This localized quality enhancement achieves the required mechanical strength without uniformly increasing material usage and manufacturing complexity throughout the entire structure.
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 effectively breaks bubbles, maintains solid-gas contact, and prevents flooding, enabling efficient catalyst conditioning and dehydrogenation processes by optimizing gas and solid flow dynamics within strict mechanical and thermal constraints.
Implementation Method 1
subway grating is an excellent choice as it breaks large bubbles into small bubbles while not restricting radial motion in the bed
Implementation Method 2
each horizontal chord comprises a structural member with sufficient mechanical strength to withstand fluidized forces in the vessel
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A fluid solids contacting device comprising a vessel; a first grid assembly section which comprises a plurality of horizontal chords spaced horizontally apart from each other and a plurality of grid platforms inserted between the horizontal chords; wherein each horizontal chord comprises a structural member with sufficient mechanical strength to withstand fluidized forces in the vessel; a plurality of chairs attached to an inside surface of the vessel and spaced circumferentially apart to support the structural member; and wherein each structural member is supported on one or more of the plurality of chairs is provided.