Personal Water Filter with Recirculating Piston for Constant Pressure
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Solution Overview
Problem
Current portable water purification devices face inefficiencies in filtration due to varying membrane pressure between strokes, lack of recirculation, and insufficient operating pressure, particularly when using ultra-filtration, nano-filtration, or reverse osmosis membranes, leading to suboptimal water treatment and high mortality rates from contaminated water sources.
Innovation Solution
A personal water purification device with a pressurized circuit and two pumping means, featuring a high pressure piston and a circulation piston that maintains constant pressure on the membrane filter through recirculation, allowing for efficient filtration using ultra-filtration, nano-filtration, or reverse osmosis membranes, and enabling the device to operate without discharging concentrate, enhancing filtration efficiency and effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single pumping means is used to pressurize water for membrane filtration, then the device structure is simple, but the membrane pressure varies significantly between strokes causing inefficient filtration
Solution Approach 1:
The single pumping means is divided into two separate pumping means: a high pressure piston for generating filtration pressure and a circulation piston for maintaining constant pressure and recirculating concentrate. This segmentation allows each piston to perform its specific function independently, resolving the contradiction between structural simplicity and filtration efficiency.
Solution Approach 2:
The circulation piston continuously recirculates the concentrate back through the membrane filter during both upstroke and downstroke, maintaining constant pressure on the membrane surface. This continuous action eliminates the pressure variations that occur with single-pump systems, ensuring consistent filtration efficiency without significantly increasing overall device complexity.
2Reliability
If high pressure is applied to the membrane filter, then filtration effectiveness increases, but concentrate concentration at membrane surface increases causing osmotic pressure buildup
Solution Approach 1:
The circulation piston continuously recirculates the concentrate solution back through the membrane filter, preventing concentration buildup at the membrane surface. This continuous recirculation maintains high filtration effectiveness while preventing osmotic pressure from rising to counterproductive levels.
Solution Approach 2:
The circulation piston performs reciprocal motion (upstroke and downstroke) to periodically recirculate the concentrate, creating a periodic flushing action that prevents sustained concentration buildup at the membrane surface while maintaining overall high pressure filtration conditions.
3Adaptability or versatility
If manual pumping is used to achieve high pressure filtration, then the device is portable and requires no external power, but the pressure fluctuates between strokes reducing filtration consistency
Solution Approach 1:
The circulation piston operates continuously during both upstroke and downstroke to maintain constant pressure on the membrane filter. This continuous operation smooths out the pressure fluctuations inherent in manual pumping, providing consistent filtration performance while maintaining portability and manual operation capability.
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 device achieves consistent high-pressure filtration, increasing the filtration efficiency and effectiveness by maintaining constant pressure on the membrane, allowing for effective treatment of water using ultra-filtration, nano-filtration, or reverse osmosis membranes, thereby improving water quality and reducing water-borne diseases.
Implementation Method 1
The membrane type filtration can be selected to be: ultra-filtration, nano-filtration or reverse osmosis
Implementation Method 2
The membrane type filtration can be selected to be: ultra-filtration, nano-filtration or reverse osmosis
Implementation Method 3
The membrane type filtration can be selected to be: ultra-filtration, nano-filtration or reverse osmosis
Implementation Method 4
Such recirculation effectively decreases the concentration of the retained substances at the membrane surface, thus decreases the osmotic pressure
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3
AI summary
The invention discloses simple to operate personal water purification device using membrane type filtration with almost constant pressure exerted to the membrane filter during the operation. The water inlet (51) is connected to the high pressure chamber (42) via non-return valve (50). The water from the chamber (42) is injected via the piston (41) into the already pressurized circuit which maintenance filter (11) working pressure. Pressurized circuit is formed in the concentrate cylinder (20) and the filtration unit (10). The fluid circulation within the pressurized circuit is enabled via circulation piston (30) motion. The permeate outlet (13) produces potable water while remaining concentrate is returned to the return chamber (21). Circulation piston (30) and high pressure piston (41) are connected via piston coupling (43) and operated, preferably, by the hand activating reciprocal motion of the piston rod (23). The membrane type filtration can be ultra-filtration membrane, nano-filtration membrane or reverse osmosis membrane.