Divided Wall Column Layout for Small-Shell External Welding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional methods for building divided wall columns face challenges due to mechanical stresses from temperature and pressure differences, which can lead to increased costs and inefficiencies, especially in smaller applications where space for welding is limited and the use of support members or thicker walls complicates the process.
Innovation Solution
The solution involves using separate preformed divided wall columns that are positioned inside a cylindrical shell column, allowing for welding from outside and reducing mechanical stresses by allowing independent movement of each column section, thus eliminating the need for internal welding and support members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the dividing wall thickness is increased to compensate for mechanical stresses, then the strength of the dividing wall is improved, but the occupation of column area increases leading to less efficient use of available area
Solution Approach 1:
The column is divided into multiple independent cylindrical sections (first cylindrical section, second cylindrical section, third cylindrical section) separated by dividing walls. Each section can move independently to accommodate thermal expansion and contraction, eliminating the need for excessive wall thickness to handle mechanical stresses from uniform heating/cooling.
Solution Approach 2:
The dividing walls are designed to allow relative movement between adjacent cylindrical sections during heating and cooling operations. This dynamic capability enables each section to expand or contract independently, reducing mechanical stress on the dividing walls and allowing thinner wall designs that occupy less column area.
2Stress or pressure
If support members or stiffening members are incorporated to prevent buckling, then the mechanical stress resistance is improved, but the cost increases and the efficiency of the distillation process is detrimentally affected
Solution Approach 1:
The column is segmented into multiple independent cylindrical sections that can move independently. This segmentation eliminates the need for support members or stiffening members to prevent buckling, as each section is structurally independent and can accommodate pressure differentials without requiring additional internal support elements that would interfere with distillation efficiency.
Solution Approach 2:
The design allows dynamic movement of dividing walls and cylindrical sections relative to each other during operation. This dynamic capability enables the column to accommodate pressure differentials and thermal stresses without requiring static support members or stiffening ribs, thereby maintaining clear column interior space for efficient distillation operations.
3Ease of manufacture
If traditional welding methods are used inside the pressure shell column, then the dividing wall can be joined to the column wall, but the welder has limited space to work especially in smaller diameter columns
Solution Approach 1:
Instead of welding dividing walls to the column wall from the interior, the invention inverts the approach by providing sealing members that extend from the exterior surface of the column wall into the column interior. The sealing members are welded to the column wall from the exterior, allowing welders to access welding locations without needing to enter the column, thereby solving the space constraint problem in smaller diameter columns.
Solution Approach 2:
Sealing members act as intermediaries between the column wall and the dividing walls. These sealing members are welded to the column wall from the exterior and then engage with the dividing walls, eliminating the need for direct interior welding of dividing walls to the column wall. This intermediary approach allows all welding operations to be performed from the exterior where adequate workspace is available.
Data Source
AI summary
A divided exchange column includes a shell column having a first longitudinal axis, a cylindrical wall spaced apart from and surrounding the first longitudinal axis and defining a first interior space, a first divided wall column having a second longitudinal axis substantially parallel to the first longitudinal axis, and a second divided wall column having a third longitudinal axis substantially parallel to the first and the second longitudinal axes, where the first divided wall column and the second divided wall column are positioned in the first interior space of the shell column.