Fluid Distribution Device for Multibed Reactors
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Solution Overview
Problem
In co-current flow reactors with multiple beds, existing systems face challenges in efficiently distributing fluids, particularly in reducing temperature and composition differences between catalyst beds, leading to uneven reactions and hot spots due to limited space for quench fluid injection and mixing, which affects catalyst life and product quality.
Innovation Solution
A device and method involving a collection tray, mixing chamber, rough distribution tray, and vapor chimneys with radially inwardly tapered cross sections to enhance fluid mixing and distribution, allowing for reduced space between reactor beds while maintaining effective fluid distribution, including vapor chimneys that reduce radial pressure gradients and vapor flow restrictions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If complex mixing and distribution systems are used to improve temperature and composition distribution, then mixing effectiveness is improved, but device complexity increases and valuable reactor space is consumed
Solution Approach 1:
The distribution system is segmented into multiple functional components: a collection tray for receiving fluid from the upper bed, a mixing chamber for quench fluid injection and mixing, a rough distribution tray for initial distribution, and a fine distribution tray for final uniform distribution. This segmentation allows each component to perform a specific function efficiently, improving overall mixing effectiveness while managing system complexity through modular design
Solution Approach 2:
A quench fluid is introduced as an intermediary substance in the mixing chamber to facilitate heat transfer and improve temperature distribution. The quench fluid acts as a mediator between the hot reactor effluent from the upper bed and the catalyst bed below, enabling effective cooling and composition mixing without requiring complex mechanical mixing devices
2Stability of the object's composition
If more space is allocated for quench fluid injection and mixing between beds, then mixing effectiveness is improved, but the reactor height increases and catalyst loading space is reduced
Solution Approach 1:
The distribution trays utilize radial flow patterns and circumferential distribution mechanisms to achieve effective mixing and distribution in the horizontal plane rather than relying solely on vertical space. The rough distribution tray creates radial outward flow while the fine distribution tray creates radial inward flow, enabling efficient fluid distribution across the bed cross-section without increasing reactor height
Solution Approach 2:
The system employs hydraulic principles to achieve effective mixing and distribution in a compact vertical space. The collection tray, mixing chamber, and distribution trays work together to create controlled fluid flow patterns that utilize pressure gradients and flow dynamics to achieve thorough mixing without requiring additional vertical space for mechanical mixers or extended quench zones
3Volume of stationary object
If the interbed space is reduced to minimize reactor size, then capital expenditure is reduced, but the ability to install new internals for improving mixing is limited
Solution Approach 1:
Multiple functions are merged into a single integrated distribution assembly that fits within the existing interbed space. The collection tray, mixing chamber, rough distribution tray, and fine distribution tray are combined into one unit that performs fluid collection, quench injection, mixing, and distribution functions simultaneously, eliminating the need for separate internals that would require additional space
Solution Approach 2:
The distribution assembly serves multiple functions within a compact design: it collects effluent from the upper bed, injects quench fluid, mixes the fluids together, and distributes the mixed fluid to the lower catalyst bed. This multi-functional design achieves effective mixing and distribution without requiring dedicated space for each function, allowing installation in existing reactors with limited interbed space
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 solution improves fluid distribution and temperature uniformity between catalyst beds, reducing the risk of hot spots and extending catalyst life, while minimizing the reactor's size and capital expenses by optimizing the use of space within the reactor shell.
Implementation Method 1
a vapor chimney body having a radially inwardly tapered cross section to reduce restriction of outward fluid flow along the rough distribution tray
Data Source
Figure 1~2
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AI summary
A fluid distribution device is presented for the collection and distribution of fluid between reactor beds. According to various aspects, the device includes a collection tray, a mixing chamber in fluid communication with the collection tray, a rough distribution tray in fluid communication with the mixing chamber, and a fine distribution tray in fluid communication with the rough distribution tray. The rough distribution tray includes a vapor chimney.