Composite Refractory Contact Device for Riser Reactor Catalyst Distribution
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Solution Overview
Problem
In catalytic cracking riser reactors, existing contact devices suffer from inhomogeneous catalyst distribution due to core-annular flow patterns, leading to sub-optimal hydrocarbon feedstock conversion and are prone to erosion and temperature-induced shape changes, lacking secure fastening methods.
Innovation Solution
The use of a composite refractory material and metal structure with a multi-toothed fork shape, fastened to the outer wall via a metal support strip, providing secure fixation, reinforcement, and protection against erosion, while maintaining turbulence and minimizing pressure drop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contact devices are made from refractory material only, then they provide erosion resistance, but they change shape due to temperature effects and are not securely fastened
Solution Approach 1:
The contact device is constructed as a composite structure comprising a metal skeleton framework embedded in refractory material. The metal skeleton provides structural stability, resistance to thermal deformation, and secure fastening capability, while the refractory material maintains erosion resistance. This composite approach resolves the contradiction by combining materials with complementary properties.
Solution Approach 2:
The metal skeleton acts as an intermediary structural element that mediates between the refractory material and the reactor wall. It provides a stable framework that secures the refractory material in place while resisting thermal effects, thereby enabling reliable fastening without compromising erosion resistance.
2Stability of the object's composition
If contact devices are added to create turbulence, then catalyst distribution improves, but pressure drop increases
Solution Approach 1:
The contact device is segmented into multiple fingers or protrusions extending from the reactor wall into the riser. This segmentation creates controlled turbulence that improves catalyst distribution while minimizing the overall obstruction to flow, thereby reducing pressure drop compared to a solid continuous structure.
Solution Approach 2:
The contact device is designed with varying finger dimensions and spacing to create localized turbulence where needed. The structure provides intense mixing in specific regions while maintaining open flow paths in other areas, achieving improved catalyst distribution with minimal pressure penalty.
3Loss of energy
If the riser reactor is provided with insulation, then heat loss is reduced, but the outer wall temperature increases
Solution Approach 1:
The metal skeleton framework serves as a thermal intermediary that conducts heat away from the refractory material toward the reactor wall and cooling systems. This allows the insulation to function effectively while preventing excessive outer wall temperature buildup through controlled heat pathways.
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
Ensures stable catalyst distribution, enhanced conversion efficiency, and reduced erosion risk through secure attachment and reinforcement, protecting internal tools and allowing for modular assembly and repair.
Implementation Method 1
These contact devices create a turbulence and thereby a more homogeneous distribution of the catalyst particles
Implementation Method 2
the refractory lining protects the steel outer wall from the erosive effect of the reaction mixture. At the same time it provides a layer of insulation to keep the outer wall cool
Implementation Method 3
catalytic cracking is a well-know process that is being used in many refineries. In catalytic cracking a hydrocarbon feedstock is fed to a riser reactor into which also a cracking catalyst is fed. During the residence time in the riser reactor the hydrocarbon feedstock is being cracked into lighter products
Implementation Method 4
The heat for the catalytic cracking reaction is supplied by the regenerated catalyst
Data Source
Figure 1~2
Figure 3~4
AI summary
Catalytic cracking riser reactor extending between an inlet for hydrocarbonaceous feed and catalyst particles and an outlet for discharging cracked products and spent catalyst particles, which riser reactor has been provided with at least one contacting device, wherein the contacting device comprises a composite of refractory material and a metal structure, which metal structure is connected to the outer wall of the riser reactor. If more contacting devices have been provided, they are preferably axially spaced apart and are disposed along the inner surface of the riser reactor.