Alternating Riser Separation Chambers for FCC Catalyst Recovery
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Solution Overview
Problem
Existing riser separation systems in the Fluid Catalytic Cracking (FCC) process suffer from low catalyst and vapor phase separation efficiency, leading to re-entrainment of catalyst and thermal degradation of hydrocarbon vapors.
Innovation Solution
The proposed apparatus features a novel design with alternating separation and collection chambers, including a concave surface and a downward pointing cusp portion in the collection chamber deflector, which enhances gas-solid separation and promotes stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional separation systems are used, then the structure is simple, but the catalyst and vapor phase separation efficiency is low
Solution Approach 1:
The separation system is divided into multiple functional chambers including a separation chamber with a riser outlet, a collection chamber with a deflector, and a dipleg. This segmentation allows each chamber to perform a specific separation function, improving overall separation efficiency while maintaining manageable system complexity through modular design
Solution Approach 2:
The invention introduces a vertical dimension to the separation process by using a downward-pointing cusp portion in the deflector and a dipleg extending into the collection chamber. This three-dimensional configuration creates multiple flow paths and separation zones, enhancing separation efficiency beyond what conventional two-dimensional separators can achieve
2Reliability
If conventional separation chambers are used, then the design is simple, but re-entrainment of catalyst occurs
Solution Approach 1:
The deflector with its downward-pointing cusp portion is positioned to intercept and redirect the gas-solid flow before it can cause re-entrainment. This preliminary action prevents catalyst particles from being lifted back into the vapor phase, ensuring stable separation without requiring additional active control mechanisms
Solution Approach 2:
The deflector features a curved, cusp-shaped surface that smoothly redirects the gas-solid flow. This curved geometry is more effective than sharp edges or flat surfaces at guiding flow patterns and preventing turbulence that could cause re-entrainment, while adding only moderate structural complexity
3Object-affected harmful factors
If conventional dipleg design is used, then the structure is simple, but thermal degradation of hydrocarbon vapors occurs
Solution Approach 1:
The dipleg is designed to extend downward into the collection chamber, extracting the gas-solid flow from the main reaction zone and directing it to a separate collection area. This extraction removes hydrocarbon vapors from the high-temperature environment, preventing thermal degradation while the dipleg structure itself remains relatively simple
Solution Approach 2:
The collection chamber acts as an intermediary zone between the separation chamber and the outlet. This intermediate space allows the gas-solid flow to cool and stabilize before exiting, preventing direct contact between hot vapors and cooler downstream equipment, thereby reducing thermal degradation without requiring complex temperature control systems
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 design improves catalyst and vapor phase separation efficiency, reduces re-entrainment, and minimizes thermal degradation of hydrocarbon vapors, resulting in higher product yield and quality.
Implementation Method 1
a downward pointing cusp portion in the collection chamber deflector, which enhances gas-solid separation
Implementation Method 2
the proposed apparatus features a novel design with alternating separation and collection chambers, including a concave surface and a downward pointing cusp portion in the collection chamber deflector, which enhances gas-solid separation
Implementation Method 3
hot catalyst comes in contact with liquid oil feed causing it to vaporize
Implementation Method 4
finely divided solid catalyst particles promote cracking reactions by providing both the heat for the reaction and the catalytic activity
Implementation Method 5
As catalyst passes through the stripping zone the hydrocarbon vapor between, and inside, the particles are removed by a counter current flow of stripping steam
Implementation Method 6
the coke is burned off, and catalytic activity is restored. The regeneration step releases energy and raises the catalyst temperature
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
An apparatus includes a riser reactor within the reaction vessel. The riser reactor defines a longitudinal axis and including a riser reactor inlet at one end and at least one riser reactor outlet at an opposite end. The apparatus includes a separation vessel including at least one separation chamber and at least one collection chamber distributed in an alternating manner about the longitudinal axis. Each separation chamber comprises two vertical lateral walls which also comprise a wall of an adjacent one of the at least one collection chamber. A lateral separation chamber outlet is defined in at least one of the vertical lateral walls to provide fluid and particle communication from the lateral separation chamber to the adjacent one of the at least one collection chamber. The separation vessel includes at least one collection chamber deflector positioned in the at least one collection chamber.