Radial-Crossflow Distillation Tray Assembly for Divided Wall Columns

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Solution Overview

Problem

Conventional divided wall exchange columns face inefficiencies in vapor-liquid contact and area utilization, particularly in cryogenic air separation processes, due to the limitations of traditional crossflow tray designs which result in suboptimal vapor flow areas and tray component sizing.

Innovation Solution

The design of a radial-crossflow tray assembly with radially oriented downcomers and liquid receiving areas, where each tray is positioned alternately in a stacked arrangement, optimizing vapor flow paths and liquid distribution across the trays, and incorporating radial downcomers and liquid receiving areas at specific angles to enhance mass transfer efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If conventional crossflow tray designs are used in divided wall exchange columns, then the tray structure is simple and easy to manufacture, but the vapor flow area is suboptimal and area utilization is inefficient

Engineering Contradiction:
Improvevapor flow areaVSAvoidtray structure complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent applies curvature by transitioning from conventional straight-line tray layouts to radial configurations where downcomers and liquid receiving areas are arranged in arcs and circles. The radial downcomers extend from the column center outward at specific angles, creating curved flow paths that increase vapor flow area while maintaining structural feasibility through standardized radial components.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent utilizes angular positioning in the radial plane to optimize vapor flow area. By arranging downcomers at specific angles (e.g., 45°, 90°, 135°, 180°) and configuring liquid receiving areas with radial axes at predetermined angles to the dividing wall, the design adds angular dimensionality to the tray layout, maximizing space utilization without increasing vertical or radial complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If radial downcomers are positioned at specific angles to the dividing wall, then mass transfer efficiency is enhanced and vapor-liquid contact is improved, but tray assembly complexity increases

Engineering Contradiction:
Improvemass transfer efficiencyVSAvoidtray assembly complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies local quality by positioning downcomers and liquid receiving areas at specific angular locations relative to the dividing wall. Each radial downcomer is configured with its radial axis at a predetermined angle (e.g., 45°, 90°, 135°, 180°) to optimize local vapor-liquid contact conditions in different regions of the column, enhancing mass transfer efficiency where needed while maintaining simpler configurations in other areas.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs asymmetric angular positioning of tray components relative to the dividing wall. Rather than symmetric placement, downcomers are positioned at specific non-uniform angles to optimize vapor flow distribution and liquid-vapor contact patterns, creating asymmetric flow paths that enhance mass transfer efficiency while managing assembly complexity through standardized angular increments.

Inventive Principle:
Principle #4Asymmetry

3Area of stationary object

If trays are stacked alternately with optimized radial configurations, then column space utilization is maximized and vapor flow area increases by over 10%, but manufacturing and assembly difficulty increases

Engineering Contradiction:
Improvecolumn space utilizationVSAvoidtray manufacturing and assembly
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

The patent segments the tray assembly into modular radial components: radial downcomers with standardized angular positions, liquid receiving areas with predetermined radial axis orientations, and vapor flow paths configured in radial zones. This segmentation allows each component to be manufactured independently using standardized radial patterns, facilitating assembly while achieving over 10% increased column space utilization through optimized radial configurations.

Inventive Principle:
Principle #1Segmentation

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 increases vapor flow area by over 10% compared to conventional designs, improving the efficiency of vapor-liquid contact and making more effective use of the available column space, especially in larger columns, while allowing for efficient mixing of liquid compositions.

Implementation Method 1

Vapour generated in the lower portion of the column passes upward through perforations in the decking, while the liquid flows downward from tray to tray countercurrent to the vapour

Methodology Applied
Scientific EffectMass transfer: Diffusion

Implementation Method 2

the liquid flows downward from tray to tray countercurrent to the vapour

Methodology Applied
Scientific EffectGravity flow: Gravitation

Implementation Method 3

In divided wall columns, a dividing wall is located in the interior space of the column. The dividing wall generally is vertical. Two different mass transfer separations may occur on either side of the dividing wall.

Methodology Applied
Scientific EffectPhysical separation: Physical Containment

Data Source

PatentEP2286885B1Radial-crossflow distillation trays for divided wall column applications
Publication Date: 2016.05.18 AIR PROD & CHEM INC
  • EP2286885B1 patent drawingFigure 1~2
  • EP2286885B1 patent drawingFigure 3~4
  • EP2286885B1 patent drawingFigure 5~6

AI summary

An assembly of trays (10, 20) in a divided wall column having an inner column wall (11), a dividing wall (14), and an interior space comprising a first tray (10) comprising at least one radial downcomer (12, 32, 52) adjacent the dividing wall (14) and extending radially toward the inner column wall (11) a first substantial distance, and a first liquid receiving area having a radial axis at a first angle to the dividing wall (14) and extending radially toward the inner column wall (11) a second substantial distance; and a second tray (20) below the first tray (10), the second tray (20) comprising at least one other downcomer (26, 46, 66) having a radial axis at a second angle to the dividing wall (14) and extending radially toward the inner column wall (11) a third substantial distance, and at least one second liquid receiving area adjacent the dividing wall (14) and extending radially toward the inner column wall (11) a fourth substantial distance.