Instruments that provide accurate data monitoring and, that are well suited for use, are the cornerstone of supporting research experiments. In order to verify and guarantee the compliance of the dust collector discharge with the national air quality standards, the particle size distribution and concentration of dust-containing gases need to be measured online. A research team from the School of Chemical Engineering of a university in Sichuan in the research project “Application of Dilution Technology in Particle concentration Detection of High-humidity Aerosol”. A variety of instruments such as Palas® Light scattering aerosol spectrometer were selected for experimental testing. Thanks to Palas® instrument, reliable data on the number and size distribution of particles in aerosols can be obtained. The university’s research team has completed several research results in this project.
Palas® Measurement Solutions
The university is a major national university. Its School of Chemical Engineering has established a range of chemical research, from basic to the transformation of engineering applications, Integrated scientific research system from chemical process development to chemical equipment design. The research team encountered Palas® through the recommendation of a professor at the Technical University of Vienna, Austria, after the experimental project was in the preparatory phase. After a careful review of the performance of the Palas® instruments. The RBG 2000 powder generator, VKL 10 aerosol dilution system, and Welas® Digital 2000 light scattering aerosol Spectrometer were selected as the instruments for the experiment.
Based on the measurement principle of light scattering detection device, a combined dilution and heating method was used to design an online detection system for high humidity aerosol particle concentration. The research team has achieved online detection of the emission concentration and particle size distribution of dust-containing gases. Pural NF particles in a naturally dry hygroscopic state are dispersed as aerosols by various instruments such as Palas® Welas® Digital 2000, RBG 2000 and VKL 10. The particle size distribution of particles in different states was then monitored and compared with Spectrometer to characterize the offset of particle size distribution in different humidity. The test results are shown in the following figure:
Particle size distribution of raw aerosol gas in unused condition
From the figure above, it can be seen that the particle size distribution of the hygroscopic particles is obviously different from that of the dry particles. The particle size distribution of the particles after moisture absorption was shifted to the direction of particle size reduction as a whole, and the concentration ratio of particles around 0.3 μm increased significantly. Take a particle size of 0.294μm as an example: the number concentration ratio was 0.069 in the dry state and 0.084 in the natural hygroscopic state, an increase of 22.7%. It was verified that the particle size and its distribution change in aerosol due to moisture absorption and condensation in high humidity environment. This leads to biased test results. The particle size distribution of the aerosol after dilution and drying by the diluter is basically the same as the particle size of the dry aerosol.
Schematic diagram of online inspection system
Constantly optimized stability monitoring
The main detection instrument in the experiment, the Welas® Digital series, has now been upgraded to a Promo® series aerosol spectrometer. The unique design of the Palas® Promo® particle size spectrometer family allows for:
· Up to 106/cm3 particle number concentration limit, no dilution system required
· 256 raw sampling channels support up to 128 channels of output particle size distribution information
· Interchangeable sensors provide greater flexibility for different applications
· High temperature and high-pressure sensors are available, allowing for use at pressures up to 10 bar and temperatures from -120°C to 470°C.
Palas® is pleased to provide strong technical support for research projects at Sichuan universities. In the future, we expect more opportunities to cooperate with universities and research institutions to help achieve research breakthroughs in aerosol detection.
If you are interested in the technical article “ Application of Dilution Technology in Particle concentration Detection of High-humidity Aerosol “, please register now to download the pdf file.
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Promo® 3000 Aerosol Spectrometer
Advantages
· Measuring range of 0.2 to 100 µm (4 measuring ranges selectable in one device)
· Up to four measuring ranges in only one device:
– 0,2 µm – 10 µm
– 0,3 µm – 17 µm
– 0,6 µm – 40 µm
– 2 µm – 100 µm (additionally for sensors 2300 and 2500)
· Up to 128 size channels per measuring range
· Concentration range of 1 particle/cm3 to 106 particles/cm3
· Calibration curves for different refractive indices
· Very high and reproducible counting efficiency rate starting at 0.2 µm
· Optical fiber technology
· Simple operation with a large touch display
· Calibration, cleaning and lamp replacement can all be performed independently by the customer
· External control by RS 232 or Ethernet
· With analysis software PDAnalyze
· Optional: Software PDControl for operation as Welas® digital available
· Low maintenance
· Reliable function
· Reduces your operating expenses
Applications
· Emission monitoring of installations
· Control of grinding and classification processes
· Monitoring of production processes in the food, pharmaceuticals and chemicals industries
· Testing of complete filters, inertial and wet separators or electrostatic precipitators
Palas® China will arrange a series of online webinars both in English and Chinese for Ambient air quality continuous monitoring system, Palas® SMPS scanning mobility particle sizer, Palas® Promo® & Aerosol Generator & Dilution system, ISO 16890 filter media tester, Palas® MFP 3000 G, ISO 29463-3 filter media tester, Palas® MFP Nano plus 4000, ISO 17536 Fractional filtration efficiency tester of Oil Mist Separator, Palas® HMT 1000, as well as Particle Distribution Measurement Devices Introduction – Optical Scattering Method and many other solutions. If interested in the webinars for our products, you are more than welcome to register on our official website and get the latest webinar plan!
Topic: Ultrafine Particle Monitoring and Research
Time: Friday, October 28, 2022 15: 00 – 16: 00
Speaker: Mr. Yi Fangjie
Market Manager Industry and Science at Palas® China
You are welcome to register for the conference!
Click here now to register for the conference