Batch Reverse Osmosis System with Integrated Circulation
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Solution Overview
Problem
Reverse osmosis systems face high costs due to the need for reinforced components to withstand pressures exceeding 1,000 psi, which increases the number of components required and reduces practical permeate recovery from seawater.
Innovation Solution
A batch-operated reverse osmosis system with a pressure tank divided into three volumes, where membranes generate permeate and a circulation pump recirculates brine, reducing the need for reinforced components by using lightweight materials for tube sheets and optimizing fluid passage and circulation within the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If reinforced components are used to withstand high pressures exceeding 1,000 psi, then system strength and reliability are improved, but system cost and device complexity increase
Solution Approach 1:
The patent extracts the high-pressure containment function from multiple distributed components (membrane housings, brine tanks, pipes) and concentrates it into a single pressure vessel. This eliminates the need for multiple reinforced components throughout the system, reducing overall complexity while maintaining the required strength to withstand pressures exceeding 1,000 psi.
Solution Approach 2:
The patent combines multiple high-pressure components into a single integrated pressure vessel that houses the membranes and contains the high-pressure feed stream. This merging eliminates the need for separate reinforced membrane housings, brine tanks, and interconnecting pipes, thereby reducing the number of components that require reinforcement while maintaining system strength.
2Reliability
If multiple reinforced components are used throughout the system, then pressure containment reliability is improved, but manufacturing cost increases
Solution Approach 1:
The patent extracts the pressure containment function from multiple distributed components and concentrates it into a single pressure vessel. This reduces the number of components requiring expensive reinforced manufacturing, thereby lowering overall manufacturing cost while maintaining pressure containment reliability through the single robust vessel design.
Solution Approach 2:
By concentrating pressure containment into a single vessel, the patent allows other components (membranes, pumps, manifolds) to be made from less expensive materials. While the pressure vessel requires reinforcement, the elimination of reinforced membrane housings, brine tanks, and pipes results in net manufacturing cost reduction.
3Productivity
If standard seawater RO systems are used, then permeate recovery reaches about 50%, but further recovery becomes impractical due to increasing solution concentration
Solution Approach 1:
The patent implements continuous operation by integrating a brine recirculation system that continuously returns concentrate from the pressure vessel back to the feed stream inlet. This continuous recirculation allows the system to maintain productive operation at high recovery ratios by preventing excessive concentration buildup, enabling permeate recovery to exceed the traditional 50% limit of batch systems.
Solution Approach 2:
The patent recovers the concentrate stream by recirculating it back into the feed stream rather than discarding it. This recovery and reuse of the concentrated solution allows the system to operate at higher permeate recovery ratios by continuously managing solution concentration, thereby improving productivity without being limited by the 50% recovery constraint of standard systems.
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 system reduces the number of components needing reinforcement, lowers operational costs, and maintains effective permeate recovery by optimizing pressure management and fluid circulation, allowing for continuous operation with reduced turbulence and mixing.
Implementation Method 1
A reverse osmosis system involves pressurizing a solution with an applied pressure greater than an osmotic pressure created by the dissolved salts within the solution. The osmotic pressure is generally proportional to the concentration level of the salt.
Implementation Method 2
The osmotic pressure is generally proportional to the concentration level of the salt. The approximate osmotic pressure in pounds-per-square-inch is the ratio of the salt mass to water mass times 14,000.
Data Source
AI summary
A reverse osmosis system and method for operating the same includes a pressure tank having a first end and a second end, the pressure tank has a first volume adjacent to the first end and a second volume adjacent to the second end and a third volume between the first volume and the second volume and a fluid passage fluidically coupling the second volume to the first volume. The reverse osmosis system also includes a plurality of membranes disposed within the third volume generating permeate and a permeate manifold receiving permeate from the membranes and fluidically communicating permeate out of the pressure tank. A feed line couples feed fluid into the pressure tank. A first pump pressurizes the feed line. A second pump is disposed within the tank and circulates brine fluid from the second volume through the fluid passage.