Approach for correcting particle size distribution measured by optical particle counter in high-pressure gas pipes

Abstract. An optical particle counter (OPC) is used in conjunction with lidar measurements to examine the characteristics of the particle size distribution in cirrus cloud in the tropical tropopause layer (TTL) over Thailand where the TTL is defined as the height at which temperature is lower than −75°C in this paper. Of 11 OPC launches, cirrus cloud was detected at 10–15 km high on 7 occasions, cirrus was detected in the TTL in 6 cases, and simultaneous OPC and lidar measurements were made on two occasions. Comparison of lidar and OPC measurements reveal that the cloud heights of cirrus in the TTL varies by several hundred meters over distances of tens kilometers; hence the height is not always horizontally uniform. The mode radii of particles constituting the clouds are estimated by lidar and OPC measurements to be less than approximately 10 μm. The regression lines of the particle size distribution with and without cirrus cloud exhibit similar features at equivalent radii of <0.8 μm. Enhancement in the integrated number concentration at radii greater than 0.8 μm indicates that liquid particles tend to be frozen at a radius of 0.8 μm, with cirrus clouds above 10 km exhibiting similar features. On the other hand, enhancement in the particle size distribution at radii greater than 0.9 μm and a peak at around 0.8 μm in the ratio of the standard deviation of count values to that of the Poisson distribution of the averaged count values are common features of cirrus clouds in the TTL, where the ratio shows the vertical homogeneity of the particle number. These typical features suggest that the transition from liquid, sulfuric acid aerosol, to ice is more observable in the TTL and the timing of freezing may vary with height in the TTL.

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Characteristics of particle size distributions in the tropical tropopause based on optical particle counter and lidar measurements

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-7-1595-2007 ◽

2007 ◽

Vol 7 (1) ◽

pp. 1595-1622

Author(s):

S. Iwasaki ◽

K. Maruyama ◽

M. Hayashi ◽

S. Y. Ogino ◽

H. Ishimoto ◽

...

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Cirrus Clouds ◽

Cirrus Cloud ◽

Particle Counter ◽

Tropical Tropopause ◽

Cloud Models ◽

Lidar Measurements ◽

Optical Particle Counter

Abstract. An optical particle counter (OPC) is used in conjunction with lidar measurements to examine the characteristics of the particle size distribution in cirrus cloud at the tropical tropopause (TT) over Thailand. Of 11 OPC launches, cirrus cloud was detected at 10–15 km high on 7 occasions, cirrus was detected at the TT in 6 cases, and simultaneous OPC and lidar measurements were made on two occasions. Comparison of lidar and OPC measurements reveal that the cloud height of cirrus in the TT varies by several hundred meters over distances of tens kilometers; hence the height is not horizontally uniform. The mode radii of particles constituting the clouds are estimated by lidar and OPC measurements to be less than approximately 10 μm. The regression lines of the particle size distribution with and without cirrus cloud exhibit similar features at equivalent radii of <0.7 μm. Enhancement in the integrated number concentration at radii greater than 0.7 μm indicates that liquid particles tend to be frozen at a radius of 0.7 μm, with cirrus clouds above 10 km exhibiting similar features. In addition, common features of cirrus clouds at the TT include a local maximum in the particle size distribution at 2.0 μm and a peak between 0.5 μm and 1.7 μm in the ratio of the standard deviation of count values to that of the Poisson distribution of the averaged count values. Each feature implies that all ice particles in the clouds may be nucleated by the same mechanism and particles in this size range are actively frozen at the TT. These parameters are thus good indicators for checking the results of cirrus cloud models in the TT.

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Particle Size Effects on Selectivity in Confined Bed Comminution

Minerals ◽

10.3390/min11040342 ◽

2021 ◽

Vol 11 (4) ◽

pp. 342

Author(s):

Holger Lieberwirth ◽

Lisa Kühnel

Keyword(s):

Particle Size ◽

High Pressure ◽

Particle Size Distribution ◽

Size Distribution ◽

Size Effects ◽

Experimental Investigations ◽

Ore Processing ◽

Tumbling Mills ◽

Particle Bed ◽

Vertical Roller

Confined bed comminution in high-pressure grinding rollers (HPGRs) and vertical roller mills (VRMs) was previously used preferably for grinding comparably homogeneous materials such as coal or clinker. Meanwhile, it started to complement or even replace tumbling mills in ore beneficiation with ore and gangue particles of rather different breakage behaviors. The selectivity in the comminution of a mixture of particles with different strengths but similar particle size distribution (PSD) of the constituents in a particle bed was investigated earlier. The strength of a material is, however, also a function of particle size. Finer particles tend to be more competent than coarser ones of the same material. In industrial ore processing using confined bed comminution, this effect cannot be neglected but even be exploited to increase efficiency. This paper presents research results on this topic based on experimental investigations with model materials and with natural particles, which were stressed in a piston–die press. It appeared that the comminution result substantially depends on the material characteristics, the composition of the mixture and the PSD of the constituents. Conclusions will be drawn for the future applications of selective comminution in mineral processing.

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The effects of fermentation conditions on yeast cell debris particle size distribution during high pressure homogenisation

Bioprocess Engineering ◽

10.1007/bf00369846 ◽

1995 ◽

Vol 14 (1) ◽

pp. 1-8 ◽

Cited By ~ 16

Author(s):

S. F. Siddiqi ◽

M. Bulmer ◽

P. Ayazi Shamlou ◽

N. J. Titchener-Hooker

Keyword(s):

Particle Size ◽

High Pressure ◽

Particle Size Distribution ◽

Yeast Cell ◽

Size Distribution ◽

Cell Debris ◽

Fermentation Conditions ◽

Debris Particle

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Effect of high-pressure treatment on oscillatory rheology, particle size distribution and microstructure of microalgae Chlorella vulgaris and Arthospira platensis

Algal Research ◽

10.1016/j.algal.2021.102617 ◽

2022 ◽

Vol 62 ◽

pp. 102617

Author(s):

Jasim Ahmed ◽

Vinod Kumar

Keyword(s):

Particle Size ◽

High Pressure ◽

Particle Size Distribution ◽

Size Distribution ◽

Chlorella Vulgaris ◽

Pressure Treatment ◽

High Pressure Treatment ◽

Oscillatory Rheology

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Simulation of particle size distribution changes occurring during high-pressure disruption of bakers' yeast

Biotechnology and Bioengineering ◽

10.1002/(sici)1097-0290(19960420)50:2<145::aid-bit4>3.0.co;2-m ◽

1996 ◽

Vol 50 (2) ◽

pp. 145-150 ◽

Cited By ~ 28

Author(s):

S. F. Siddiqi ◽

N. J. Titchener–Hooker ◽

P. Ayazi Shamlou

Keyword(s):

Particle Size ◽

High Pressure ◽

Particle Size Distribution ◽

Size Distribution

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Modelling the Effect of Processing Parameters of Continuous Flow High Pressure Throttling System and Microfluidizer on Particle Size Distribution of Soymilk

International Journal of Food Engineering ◽

10.1515/ijfe-2012-0005 ◽

2013 ◽

Vol 9 (2) ◽

pp. 217-225 ◽

Cited By ~ 1

Author(s):

Litha Sivanandan ◽

Romeo T. Toledo ◽

Rakesh K. Singh

Keyword(s):

Particle Size ◽

High Pressure ◽

Particle Size Distribution ◽

Size Distribution ◽

Temperature Rise ◽

Continuous Flow ◽

Volume Fraction ◽

Emulsion Stability ◽

Processing Parameters ◽

Flow Rates

AbstractTexture, appearance, and emulsion stability of soymilk are affected by the size and distribution of suspended particles. To produce soymilk which contains all solids in the soy, whole dehulled beans were used in the study. A microfluidizer with throttling valve attachment was used to study the influence of various pressure levels on the particle size distribution of soymilk. Soymilk was processed with a continuous flow high pressure throttling (CFHPT) system to study the effects of different pressures and flow rates in the temperature rise and particle size distribution of soymilk. The results showed that there existed a significant effect of flow rate through the CFHPT on the particle size suspended in soymilk. Temperature rise was proportional to increase in pressure of the CFHPT system. Significant decrease in particle size of soymilk was obtained by increasing pressure for both CFHPT and microfluidizer. Empirical models were established between the pressure applied, volume fraction of particle size, and particle size diameter obtained for soymilk in each system.

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An Improved High-Pressure Roll Crusher Model for Tungsten and Tantalum Ores

Minerals ◽

10.3390/min8110483 ◽

2018 ◽

Vol 8 (11) ◽

pp. 483 ◽

Cited By ~ 7

Author(s):

Hernan Anticoi ◽

Eduard Guasch ◽

Sarbast Ahmad Hamid ◽

Josep Oliva ◽

Pura Alfonso ◽

...

Keyword(s):

Particle Size ◽

High Pressure ◽

Distribution Function ◽

Particle Size Distribution ◽

Size Distribution ◽

Single Particle ◽

Pressing Force ◽

Product Particle ◽

Compression Condition ◽

Roll Crusher

An improved approach is presented to model the product particle size distribution resulting from grinding in high-pressure roll crusher with the aim to be used in standard high-pressure grinding rolls (HPGR). This approach uses different breakage distribution function parameter values for a single particle compression condition and a bed compression condition. Two materials were used for the experiments; altered Ta-bearing granite and a calc-silicate tungsten ore. A set of experiments was performed with constant operative conditions, while varying a selected condition to study the influence of the equipment set-up on the model. The material was comminuted using a previously determined specific pressing force, varying the feed particle size, roll speed and the static gap. A fourth group of experiments were performed varying the specific pressing force. Experimental results show the high performance of the comminution in a high-pressure environment. The static gap was the key in order to control the product particle size. A mathematical approach to predict the product particle size distribution is presented and it showed a good fit when compared to experimental data. This is the case when a narrow particle size fraction feed is used, but the fit became remarkably good with a multi-size feed distribution. However, when varying the specific pressing force in the case of the calc-silicate material, the results were not completely accurate. The hypothesis of simultaneous single particle compression and bed compression for different size ranges and with different parameters of the distribution function was probed and reinforced by various simulations that exchanged bed compression parameters over the single particle compression distribution function, and vice versa.

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