Annular Divided Wall Column Design for Independent Thermal Expansion
Find Innovative SolutionsGenerate Solutions
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 conical transition wall to isolate the annulus and core column regions, allowing independent thermal expansion and contraction, and uses structured packing elements with varying surface area densities and geometries in both regions, along with specialized collectors and distributors to enhance vapor and liquid distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a divided-wall column is used to reduce capital cost and space requirements, then the number of columns is reduced, but maldistribution of vapor and liquids occurs
Solution Approach 1:
The column is divided into multiple independent sections (core column region and annulus column region) separated by a divided wall, with each section having its own packing elements and distribution systems. This segmentation allows independent optimization of each region while maintaining overall system efficiency.
Solution Approach 2:
Different packing elements with varying surface area densities are used in different regions of the column. The core column region and annulus column region have tailored packing configurations to optimize local mass transfer performance and ensure proper vapor-liquid distribution in each specific zone.
2Ease of manufacture
If a divided-wall column is used to reduce capital cost and space requirements, then the number of columns is reduced, but thermal expansion differences between inner and outer shells reduce performance
Solution Approach 1:
The divided wall structure incorporates flexible connection elements and expansion joints that allow the inner and outer shells to expand and contract independently in response to thermal changes. This flexibility prevents stress buildup and maintains structural integrity and separation efficiency under varying thermal conditions.
3Productivity
If structured packing is used in divided-wall columns, then mass transfer efficiency is improved, but liquid maldistribution due to large wall surface areas worsens
Solution Approach 1:
Collection and distribution systems are introduced as intermediary structures between the vapor-liquid flow and the packing elements. These systems include collection channels and distribution channels that actively manage liquid flow, ensuring uniform distribution across the packing surfaces and preventing maldistribution caused by the divided wall geometry.
4Strength
If the second annular column wall is rigidly connected to the first annular column wall, then structural stability is improved, but independent thermal expansion is prevented
Solution Approach 1:
The connection between the first and second annular column walls transitions from rigid to dynamic, allowing relative movement between the walls. The pivoting arms provide a mechanism that maintains structural connection while accommodating differential thermal expansion, enabling each wall to respond independently to thermal conditions.
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 the efficiency and performance of the rectification process by reducing capital costs and space requirements, while maintaining effective vapor and liquid distribution and thermal management.
Implementation Method 1
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
Implementation Method 2
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
Implementation Method 3
an annular divided wall column for the cryogenic rectification of air or constituents of air
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.