Permselective membrane module cleaning via segmented air scrubbing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hollow fiber membrane modules face challenges in efficiently cleaning suspended solids from the center of large modules, leading to re-deposition on the membrane surface, and existing manufacturing methods are prone to defects and complexity.
Innovation Solution
A method for manufacturing a permselective membrane module using premolded holders with slit holes for air scrubbing and a cleaning pipe system that effectively discharges suspended solids, ensuring efficient cleaning and reducing manufacturing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If air is introduced from the lower part of a hollow fiber membrane module for cleaning, then suspended solids can be discharged from the outer periphery, but air cannot reach the hollow fiber membranes near the center of large modules, resulting in incomplete cleaning
Solution Approach 1:
The module is divided into multiple sections with air inlets distributed at different locations (lower part and side surfaces). This segmentation allows air to reach both the outer periphery and center regions of the membrane bundles, ensuring complete cleaning coverage without requiring a single complex air introduction system.
Solution Approach 2:
Air inlets are provided not only at the lower part but also at the side surfaces of the module. This multi-dimensional air introduction approach ensures that air bubbles can reach hollow fiber membranes at various positions (center and periphery) through different pathways, solving the limitation of single-point air introduction.
2Ease of operation
If hollow fiber membranes are strongly shaken during air scrubbing to discharge suspended solids, then cleaning effectiveness improves, but membrane breakage increases due to friction with binding members
Solution Approach 1:
The binding members that cause friction and membrane breakage are removed from the module structure. Instead of binding membranes together, the invention uses a partition wall structure that separates bundles without contacting the membranes, eliminating the source of mechanical damage during shaking operations.
Solution Approach 2:
A partition wall structure is introduced as an intermediary element to separate and support hollow fiber membrane bundles. This partition wall does not directly contact the membranes, allowing them to be shaken for cleaning without the friction and damage caused by direct binding member contact.
3Productivity
If the number of hollow fiber membranes in a module is increased to handle larger water volumes, then filtration capacity improves, but the difficulty of efficiently discharging suspended solids from the center of membrane bundles increases
Solution Approach 1:
The module is segmented into multiple sections with distributed air inlets at the lower part and side surfaces. This segmentation ensures that even with increased number of membranes, air can reach center regions through multiple pathways, maintaining effective cleaning capability as filtration capacity increases.
Solution Approach 2:
The air scrubbing system is designed to serve multiple functions simultaneously: it cleans membranes at the outer periphery, reaches center regions through side surface inlets, and discharges suspended solids efficiently. This multi-functional design maintains effectiveness regardless of the number of membranes in the module.
4Ease of manufacture
If a U-shaped region is used to bind hollow fiber membranes, then membrane arrangement is simplified, but strong shaking during air scrubbing causes membrane breakage through friction with binding members
Solution Approach 1:
The binding members that cause friction and membrane breakage are completely removed from the structure. The U-shaped binding concept is replaced with a partition wall system that separates bundles without contacting the membranes, eliminating the source of mechanical damage while maintaining structural organization.
Solution Approach 2:
Partition walls serve as intermediaries to organize and separate hollow fiber membrane bundles without directly contacting them. This allows the membranes to be freely shaken for cleaning while the partition walls provide the necessary structural separation, eliminating the friction problem of direct binding.
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
The method improves production yield, durability, and quality, allowing effective discharge of suspended solids and reducing cleaning costs, while extending the life of the membrane module and lowering filtration costs.
Implementation Method 1
In air scrubbing, air is introduced from the lower part of a hollow fiber membrane module. The resulting bubbles rise through membranes and shake the hollow fiber membranes, thereby widening the gap between membranes and efficiently discharging the suspended solids to the outside of the module.
Implementation Method 2
When raw water is filtered using a permselective membrane module directly or after pretreatment, a pressurized or submerged type module is generally employed. With the pressurized type, permselective membranes are housed in a vessel, and raw water is fed to the membranes by means of external pressure produced by, for example a pump, and filtered.
Data Source
AI summary
To provide a method for manufacturing a module having a selectively permeable membrane wherein the surface of the selectively permeable membrane thereof can be washed with good efficiency and further contaminants having been exfoliated from the surface of the membrane by a washing operation can be discharged from the inside of a housing with good efficiency; and the above module having a selectively permeable membrane. A module wherein a selectively permeable membrane is held in a housing and both ends of the above selectively permeable membrane are fixed, the both ends of the above selectively permeable membrane are fixed to an upper holder and an under holder connected by at least one washing tube, and then, the membrane is held in the housing; and a module having a selectively permeable membrane manufactured by the above manufacturing method.