Single Pump Filtration System for UF Membrane Backwash
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Solution Overview
Problem
Conventional water and wastewater filtration systems, particularly ultrafiltration (UF) membrane systems, face issues with frequent pump cycling leading to maintenance problems and high capital costs due to the need for large backwash pumps and associated infrastructure, which are not adequately addressed by current technologies.
Innovation Solution
A filtration system comprising multiple membrane modules arranged in parallel flow, with a dedicated pump for both filtration and backwashing, utilizing automatically controllable valves and a variable-speed prime mover to manage pressure and flow, allowing for continuous operation without pump shutdowns and reducing the need for large backwash systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional UF membrane systems employ dedicated feed and backwash pumps with large backwash pumps and large diameter piping to handle high backwash flow rates, then backwash effectiveness is improved, but pump maintenance issues increase due to frequent cycling on and off
Solution Approach 1:
The patent combines the feed pump and backwash pump functions into a single pump system. The feed pump discharge is configured to also serve as the backwash pump, eliminating the need for separate backwash pumping equipment. This merging reduces the number of pumps that require maintenance and eliminates frequent cycling operations.
Solution Approach 2:
The feed pump is designed to perform multiple functions: it serves as both the feed pump during normal operation and as the backwash pump during backwash cycles. The pump's discharge conduit is configured to deliver feed to membrane modules and to deliver backwash water to the backwash distributor, enabling one pump to fulfill multiple roles in the system.
2Reliability
If conventional systems use large backwash pumps and large diameter piping to handle high backwash flow rates, then backwash performance is improved, but capital costs increase
Solution Approach 1:
The system merges the backwash pumping function with the feed pumping function, eliminating the need for separate large-capacity backwash pumps and associated large diameter piping. The feed pump and its discharge conduit are utilized for both feed delivery and backwash water delivery, significantly reducing capital equipment requirements.
Solution Approach 2:
The feed pump serves itself by also functioning as the backwash pump. The system uses its own existing infrastructure (pump and piping) to perform backwash operations, eliminating the need for dedicated backwash equipment and reducing overall system capital costs.
3Productivity
If dedicated feed pumps are used for each train to operate more efficiently, then pump efficiency is improved, but system complexity increases with multiple pumps
Solution Approach 1:
The patent merges multiple pump functions into a single pump per train, where the feed pump also serves as the backwash pump. This reduces the total number of pumps in the system while maintaining dedicated operation for each train, balancing efficiency with simplified equipment requirements.
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 solution reduces pump maintenance, lowers capital expenses by eliminating the need for large backwash systems, and enables efficient handling of sudden solids loading conditions, while maintaining consistent water supply for downstream processes.
Implementation Method 1
a pump having a pump feed conduit and a pump discharge conduit... configured to deliver feed to the membrane modules during filtration and to deliver backwash water to the backwash distributor
Implementation Method 2
a plurality of membrane modules, each having filter media therein... producing a filtrate stream
Data Source
AI summary
Water or wastewater filtration processes and systems have a plurality of membrane modules, each having filter media therein, the plurality of membrane modules arranged in parallel fluid flow, a main bottom feed conduit, a main top feed conduit, and separate feed conduits fluidly connecting the main bottom feed conduits and the main top feed conduits to respective membrane modules. A main filtrate conduit, and separate filtrate conduits fluidly connect respective membrane modules to the main filtrate conduit. A backwash conduit fluidly connects the main filtrate conduit to respective membrane modules through the main top and bottom feed conduits. A pump having a pump feed conduit and a pump discharge conduit, the pump discharge conduit fluidly connected to the main top and bottom feed conduits, and a plurality of automatically controllable valves positioned in the main top and bottom feed conduits, the main filtrate conduit, the pump discharge conduit, and the backwash conduit, with a controller configured to actuate the plurality of automatically controllable valves to control feed and backwash flows through the membrane modules using pressure developed only by the pump. The pump is preferably operated by a variable-speed prime mover.