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Sample Particle Filtration / Sample particle Separation
It is preferable to select analysers that need no sample filtration or sample conditioning equipment. Some analyser techniques can handle big particles as long as they are non abrasive and a soft structure for example TOC’s with ozone oxidation. Other analysers have no problems with these POC’s but do not analyse the content for example UV-persulphate TOC’s.
Some users demand analyser results that are stable and do not have freak peaks due to analysing now and then a big particle. They use filtration.
Many analysers need filtration because particles will clog the wetted parts in the analyser and will cause a lot of maintenance problems.
The sample filtration system should be designed very carefully.
Waste water:
- Preferable is to start using anti-isokinetic or gravimetrical separation techniques to separate particles with high mass and size;
- Use fast sample loops with a velocity of at least 1 m/s in all wetted parts!
- Preferable use analysers that can handle particles;
- Use a sample take off point on the fast sample loop to extract the sample for the analyser(s) and only filter out particles from this smaller stream;
- If necessary, use filter systems with auto blow back or ultrasonic cleaning.
Steam, condensate water and boiler feed water:
- Due to the high pressure and temperature these analyser system use pressure reducers. Pressure reducers should be protected against small particles. Filtration of very small particles is “a must”;
- The levels to be analysed are very low (ppb’s / ugram/litres). Particles will result in fouling of sample lines introducing higher absorption and memory effects;
- Particles will collect/absorb organics and will result in “freak peaks” and false alarms. Another reason to use several filters with different rates (serial);
- The first filter is a pre-filter. This filter system should be engineered in such a way that safe operation is guaranteed. We offer panels including safety block valves or redundant systems with block and bleed valves, manometers, safety instructions, etc..
A smart designed sample filter system reduces the maintenance time of the total analyser system. In a bad designed filter system the maintenance has partly moved from analyser to filter.
We are pleased to offer you specific information:
Contact ODS and/or Send us your enquiry
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