Dual Filter Sampling Probe for Continuous Process Water Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing process water analysis sampling arrangements using ultrafiltration membranes face challenges in continuous sampling due to the need for frequent backwashing and chemical cleaning, which disrupts the sampling process and reduces the service life of the membranes.
Innovation Solution
A process water analysis sampling assembly with an immersion probe featuring two fluidically separated filter units, a flushing liquid tank, and a fluidics control system that allows for simultaneous sampling and cleaning of one filter unit while the other is in use, using a combination of flushing liquids and a cleaning gas carpet to extend the service life of the membranes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical cleaning of filter membranes is used, then sampling can be performed, but the membranes cannot be cleaned sufficiently in the long run and require backwashing/chemical cleaning which interrupts sampling
Solution Approach 1:
The system divides the single filter membrane into two separate filter units (first filter unit with first filter membrane and second filter unit with second filter membrane). This segmentation allows one membrane to be cleaned while the other continues sampling, eliminating the interruption that would occur if a single membrane required cleaning.
Solution Approach 2:
The system combines mechanical cleaning (gas bubbles) and chemical cleaning (flushing liquid) into a unified cleaning process. The flushing liquid is pumped through the cleaning liquid line to clean the filter membrane from the inside, while gas bubbles provide mechanical cleaning from the outside, creating a comprehensive cleaning solution that extends membrane service life.
2Reliability
If backwashing and chemical cleaning are performed on the filter membrane, then the membrane can be cleaned sufficiently, but sampling is unavoidably interrupted for up to one hour
Solution Approach 1:
By segmenting the filtration system into two independent filter units, the system enables parallel operation where one unit samples while the other cleans. This eliminates the time loss associated with interrupting sampling for membrane cleaning, as the cleaning operation on one membrane does not affect sampling from the other membrane.
Solution Approach 2:
The system maintains continuous sampling by switching between two filter units. While the first filter membrane is being cleaned, the second filter unit continues to provide samples. The fluidics control ensures continuous operation by managing the switching and cleaning sequences, thereby maintaining the continuity of the useful sampling action without interruption.
3Device complexity
If a single filter membrane is used, then the device is simpler, but frequent cleaning interruptions reduce productivity
Solution Approach 1:
The system segments the filtration function into two separate filter units, each with its own membrane. This segmentation increases device complexity but enables continuous productivity by allowing one unit to sample while the other cleans, ultimately improving overall sampling throughput despite the added complexity.
Solution Approach 2:
Each filter unit is designed to perform multiple functions: sampling and cleaning. The fluidics control system manages both filter units universally, switching them between sampling and cleaning modes as needed. This multi-functionality allows the system to maintain high productivity by ensuring that at least one filter unit is always in sampling mode.
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 enables continuous or quasi-continuous sampling while maintaining the integrity and longevity of the ultrafiltration membranes, reducing downtime and extending the maintenance interval.
Implementation Method 1
Filter membranes used today can be micro filtration membranes or ultrafiltration membranes which are almost bacteria-proof but which cannot be cleaned sufficiently in the long run via a purely mechanical cleaning of their outer surface.
Implementation Method 2
The fluidics control comprises a pump arrangement which is fluidically connected to each of the first filter unit and the second filter unit
Implementation Method 3
a valve arrangement which comprises a plurality of switchable valves
Implementation Method 4
rising gas bubbles emerging from cleaning gas outlets in order to avoid a clogging of the filter membranes
Data Source
AI summary
A process water analysis sampling assembly includes an immersion probe having a first filter unit and a second filter unit which are fluidically separated from each other, a flushing liquid tank, and a fluidics control. The fluidics control includes a pump arrangement which is fluidically connected to each of the first filter unit and the second filter unit, at least two liquid pumps which are arranged to be mutually independent from each other, and a valve arrangement having plurality of switchable valves. The fluidics control controls a sampling and a flushing of the immersion probe. The fluidic control fluidically connects the flushing liquid tank to one of the first filter unit and the second filter unit and simultaneously connects an analysis unit to the other one of the first filter unit and the second filter unit.