Zur Fließfähigkeit von Schüttgütern – Definition und Meßverfahren

Schulze, Dr.-Ing. Dietmar

doi:10.1002/cite.330670105

Cited by 30 publications

(4 citation statements)

References 13 publications

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“…In this case, the flow properties are important for the design of such apparatus in order to avoid flow problems as flow disturbances or demixing. Schulze 22 names suitable processes for such large‐scale industrial applications. If the focus is on such technical apparatus designs, parameters other than the angle of repose and the Hausner ratio are also used.…”

Section: Theoretical Background—characterization Of Flow Properties O...mentioning

confidence: 99%

Flow properties of powdery or granular filling substances of dangerous goods packagings—Comparison of the measurement of the angle of repose and the determination of the Hausner ratio

et al. 2022

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To ensure safety when transporting dangerous goods, it is important to specify the flow properties of the respective solid filling substance of the packagings. For this purpose, the angle of repose is currently used for the UN approvals in Germany. Measurements were carried out on 12 powdery or granular substances applying the angle of repose measuring methods customary in the test centres. The results of the methods differ significantly from each other. In addition, some of the techniques cannot be applied for very cohesive or coarse‐grained materials. The results for the angle of repose show a strong scatter for some constellations (coefficient of variation more than 20%). Safety during transport of dangerous goods cannot be guaranteed with this currently practised system of measuring the angle of repose. As a consequence, an alternative parameter to characterize the flow properties of bulk materials should be used in the recognized test centers for dangerous goods packagings, such as the Hausner ratio. This approach leads to more precise test results for the substances examined (maximum coefficient of variation 2.8%). It also has advantages in terms of applicability and occupational safety. Since the flow properties are safety‐relevant, both in terms of mechanical safety and safety against the release of dangerous substances, the testing practice in the recognized test labs should be improved and standardized.

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Section: Theoretical Background—characterization Of Flow Properties O...mentioning

confidence: 99%

Flow properties of powdery or granular filling substances of dangerous goods packagings—Comparison of the measurement of the angle of repose and the determination of the Hausner ratio

et al. 2022

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“…The flow properties of dry and moist powders were determined according to the analysis method of Schulze (1995Schulze ( , 1998 in the Jenike shearing cell. The pertinent measurement results are given in Fig.…”

Section: Blue Greymentioning

confidence: 99%

Determination of the mixing time in a discontinuous powder mixer by using image analysis

Daumann

Fath

Anlauf

et al. 2009

Chemical Engineering Science

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This study reports on research results in the field of powder mixing in a discontinuously operated charge mixer. The mixing time for a confidence interval can be determined from the mixing efficiency that characterizes the mixing of the participating solid components as a function of the mixing time. The mixing efficiency is determined here with the help of an image analysis method developed for these purposes. The particle fraction, that is interesting in terms of its distribution, is partially replaced for this purpose by a similarly behaving but optically well identifiable tracer material. A dispersion coefficient can be obtained from the analysis of the mixing trial. The practical application of statistics on image analysis is described and discussed along with a description of the possibilities and limitations of the measurement method. The description of the procedure to determine the dispersion coefficient is built on that.

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“…where s 1 is the consolidating stress and s c is the unconfined yield strength. [5] The higher the flow factor was, the better the powder flowed. In this study, the flow factor was determined by a ring shear tester (RST-XS, Schulze Schu ¨ttgutmesstechnik) with a shearcell volume of 30 mL.…”

Section: Experimental Partmentioning

confidence: 99%

“…In this study, the flow factor was determined by a ring shear tester (RST-XS, Schulze Schu ¨ttgutmesstechnik) with a shearcell volume of 30 mL. [5] The untreated lactose powder exhibited ff c ¼ 3.7, which was classified (Table 1) as cohesive. [6] The measurements were carried out at a pre-shear stress of 5 000 Pa and the shear stresses were 1 000, 2 500, and 4 000 Pa.…”

Section: Experimental Partmentioning

confidence: 99%

Plasma Enhanced Chemical Vapor Deposition on Particulate Solid‐State Materials for Improved Powder Processing

Sonnenfeld

Roth

Dimitrova

et al. 2009

Plasma Processes & Polymers

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The surface of fine lactose powder particulates was modified by direct‐plasma exposure in a radio frequency (RF) discharge, in a mixture of oxygen and hexamethyldisiloxane (HMDSO) diluted in argon. Besides, the RF power (100–500 W) and the HMDSO flow rate (0–68 sccm) at constant oxygen‐to‐HMDSO flow rate ratio of 10 was varied in this study. Apart from the relatively high pressure of 2 mbar, the plasma process adopted is very much alike the plasma enhanced chemical vapor deposition of silica‐like material descending from the plasma‐chemical reaction of oxygen and HMDSO. With respect to the processability of powders in production lines to be solely gravity‐driven, as for instance in the event of dye‐filling, compression ratios (based on the powder bulk and mass density) were measured for solely gravity‐driven filling of a graduated glass. A jolting volumeter was used to provide the compressibility of the compacted powder bulk. Higher compressibility of about 20% (improvement rate) was found for both experimental series: variation of HMDSO flow rate and variation of the discharge power. In both cases, an enhancement of the flowability of the powder was found to cause the compressibility improvement.

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Zur Fließfähigkeit von Schüttgütern – Definition und Meßverfahren

Cited by 30 publications

References 13 publications

Flow properties of powdery or granular filling substances of dangerous goods packagings—Comparison of the measurement of the angle of repose and the determination of the Hausner ratio

Flow properties of powdery or granular filling substances of dangerous goods packagings—Comparison of the measurement of the angle of repose and the determination of the Hausner ratio

Determination of the mixing time in a discontinuous powder mixer by using image analysis

Plasma Enhanced Chemical Vapor Deposition on Particulate Solid‐State Materials for Improved Powder Processing

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