Parallel Flow Downcomer Tray Layout for High Liquid Capacity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional mass transfer columns face limitations in high-capacity vapor-liquid contacting due to restricted active area and downcomer configuration, leading to inefficiencies in mass transfer, particularly in high-pressure distillation systems where liquid handling capacity is critical.
Innovation Solution
The design incorporates a multiple pass, parallel flow downcomer tray with features such as weirs, liquid receiving pans, perforated baffles, bubble forming structures, and dividers to enhance liquid distribution and flow directionality across mass transfer decks, aligning with Lewis Case 2 parallel flow patterns and multiple pass configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional single pass or two pass tray configurations are used, then the tray structure is simpler, but the liquid handling capacity and mass transfer efficiency are limited
Solution Approach 1:
The tray is divided into multiple active areas separated by chordal downcomers, allowing liquid to flow in multiple passes across the tray surface. This segmentation increases the effective liquid handling capacity by distributing liquid flow across multiple paths rather than a single path, while maintaining reasonable structural complexity through the use of standard downcomer components.
2Productivity
If the active area of the tray is increased to improve vapor-liquid contacting capacity, then more mass transfer occurs, but the downcomer area becomes insufficient leading to flooding
Solution Approach 1:
The invention transitions from a single-pass linear liquid flow to a multi-pass flow pattern that utilizes the tray surface in a two-dimensional manner. Liquid flows across the tray in one direction, then returns in the opposite direction through separate active areas, effectively doubling the liquid handling capacity without increasing the vertical height or downcomer cross-sectional area, thereby preventing flooding while maintaining high contacting capacity.
3Productivity
If liquid flow rate is increased to handle high liquid rates, then more liquid is processed, but mass transfer efficiency decreases due to reduced interaction time
Solution Approach 1:
The multi-pass configuration ensures continuous liquid flow across multiple active areas, maintaining consistent liquid-vapor interaction throughout the tray. Liquid that does not fully react in the first pass continues to interact in subsequent passes, ensuring complete utilization of the liquid flow for mass transfer purposes, thereby maintaining efficiency even at high flow rates.
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 configuration improves mass transfer efficiency by optimizing liquid flow paths, reducing weir loading, and maintaining uniform driving forces across trays, resulting in enhanced capacity and performance compared to conventional designs.
Implementation Method 1
bubble forming structures, and dividers to enhance liquid distribution and flow directionality across mass transfer decks
Implementation Method 2
perforated baffles, bubble forming structures, and dividers to enhance liquid distribution and flow directionality
Implementation Method 3
a plurality of weirs disposed proximate each downcomer and configured to impede the traversing liquid flow to the downcomers
Data Source
Figure 1~3
Figure 4A~4G
Figure 4H~4K
AI summary
A multiple pass, parallel flow downcomer tray for a mass transfer column and method for liquid-vapor contacting in a mass transfer column is provided. The multiple pass, parallel flow downcomer tray has at least four mass transfer decks configured to provide contact between an ascending vapor passing upward through apertures on the tray surface and a traversing liquid on the tray surface. The tray further includes a central downcomers disposed near a central axis of the tray and two or more peripheral downcomers disposed near the edge of the tray and spaced apart from the central axis, wherein at least two of the four mass transfer decks are configured to discharge the traversing liquid into the peripheral downcomers and two of the four mass transfer decks are configured to discharge the traversing liquid into the central downcomer.