Annular divided wall column with ring shaped collectors and distributers
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Solution Overview
Problem
Existing annular divided wall column systems for cryogenic rectification face challenges such as maldistribution of vapor and liquids, lower performance due to thermal expansion/contraction differences, and inadequate pressure boundaries, leading to increased capital costs and space requirements.
Innovation Solution
The design incorporates a first and second annular column wall with a plurality of structured packing elements, ring-shaped cantilevered collectors, and ring-shaped distributors, where the second annular column wall's thermal expansion and contraction are independent of the first, and the use of support structures like pivoting arms and rolled angle rings to reduce structural complexity and enhance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If divided-wall columns are used to reduce column cost and space requirements, then capital cost and space are reduced, but maldistribution of vapor and liquids occurs and performance deteriorates
Solution Approach 1:
The column is divided into multiple independent distillation sections (annulus column region and interior core column region) separated by an inner annular wall, allowing each section to function independently while sharing the same column shell, thereby reducing overall capital cost and space requirements while maintaining separation efficiency
Solution Approach 2:
An intermediate fluid barrier wall is positioned between the annulus column region and interior core column region to prevent direct mixing of vapor and liquid streams while allowing thermal interaction, thereby maintaining proper phase distribution and preventing maldistribution issues
2Ease of manufacture
If divided-wall columns are used to reduce column cost and space requirements, then capital cost and space are reduced, but maldistribution of down-flowing liquids occurs due to large wall surface areas
Solution Approach 1:
The fluid barrier wall is extracted from direct contact with liquid streams and repositioned as an intermediate thermal barrier, eliminating its negative impact on liquid distribution while preserving its thermal function, thereby improving liquid flow distribution in the annulus region
Solution Approach 2:
Different regions of the column are designed with different structural characteristics - the annulus column region has optimized wall surface area and liquid distribution structures tailored to its specific flow patterns, while the interior core column region has its own optimized configuration, allowing each region to operate at optimal performance
3Productivity
If divided-wall columns are used with structured packing, then mass transfer efficiency is improved, but transient thermal expansion/contraction differences between inner and outer shells cause performance degradation
Solution Approach 1:
The column design accommodates dynamic thermal expansion and contraction by allowing the inner annular wall and fluid barrier wall to move independently relative to the outer shell, preventing stress buildup and maintaining structural integrity and performance stability during transient thermal conditions
Solution Approach 2:
The intermediate fluid barrier wall acts as a thermal buffer between the inner and outer shells, absorbing and distributing thermal stresses to reduce the impact of thermal expansion differences on the structured packing and overall column performance
4Area of stationary object
If divided-wall columns are used to reduce space requirements, then column footprint is reduced, but the pressure boundary between interior core and annulus regions becomes inadequate
Solution Approach 1:
The pressure boundary functions are merged into the common outer column shell, which is designed to withstand the combined pressure loads from both the annulus column region and interior core column region, thereby providing adequate pressure containment while maintaining a compact footprint
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 vapor and liquid distribution, enhances performance by allowing independent thermal expansion, and reduces capital costs and space requirements, resulting in a more efficient and cost-effective cryogenic rectification system.
Implementation Method 1
a plurality of packing elements or trays disposed within the interior core column region and the annulus column region
Implementation Method 2
one or more ring-shaped distributors disposed in the annulus column region above or below the plurality of structured packing elements
Implementation Method 3
one or more ring-shaped cantilevered collectors disposed in the annulus column region above or below the plurality of structured packing elements
Implementation Method 4
wherein thermal expansion and contraction of the second annular column wall in a radial direction and in an axial direction is independent of the thermal expansion and contraction of the first annular column wall in radial and axial directions
Data Source
AI summary
An annular divided wall column for the cryogenic rectification of air or constituents of air is provided. The annular divided wall column includes a first annular column wall and a second annular column wall disposed within the first annular column wall to define an annulus column region and an interior core column region. The present annular divided wall column further includes structured packing elements disposed within at least the annulus column region as well as a ring-shaped cantilevered collector; and a ring-shaped distributor disposed in the annulus column region above or below the plurality of structured packing elements. The thermal expansion and contraction of the second annular column wall in a radial direction and in an axial direction is independent of the thermal expansion and contraction of the first annular column wall in the radial and axial directions.