Laboratory
Our laboratory is equipped with the most modern devices. We measure for you:
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Flowability or bulk solids strength (depending on consolidation stress, storage time, temperature, humidity, composition),
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angle of internal friction,
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Wall friction (friction between bulk material and any silo wall materials such as steel, aluminum, concrete, plastic etc.),
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Bulk density (also dependent on compression stress),
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Abrasion (important for sensitive bulk goods),
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Stress ratio, wall friction coefficient and specific weight for the strength-related silo design according to DIN 1055 Part 6 or according to the new DIN EN 1991-4,
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aeration / fludization behaviour,
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specific surface according to Blaine,
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particle size distribution,
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humidity.
Depending on the application, we use the following shear testes for flowability and friction angle:
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To determine the lambda value (horizontal load ratio), also known as the K value, we use one of the world's rarest Lambda-meter.
Translation shear tester according to Jenike
The Jenike shearing tester was developed in the 1960s by Dr. Andrew W. Jenike and is therefore the forerunner of the ring shear tester. Building on the fundamentals of soil mechanics, Jenike described the behavior of bulk materials using the yield locus. He developed a theory for assessing stresses in silos. He coined the terms mass flow and funnel flow. To this day, the Jenike method is the most widely used design method for silos worldwide. We use the Jenike shear device for, for example, measurements of wall friction.
Er prägte die Begriffe Massenfluss und Kernfluss. Bis heute ist das Jenike-Verfahren das weltweit am meisten benutzte Auslegungsverfahren für Silos. Wir verweden das Jenike- Schergerät für z.B: Messungen zur Wandreibung.
Ring Shear Tester RST-01.pc
The Ring Shear Tester RST-01.pc is a shear tester. This is important because shear tester are the only internationally recognized, partially standardized, devices for measuring flow properties. The ring shear tester RST-01.pc measures the flow properties of powders and bulk materials under conditions that also prevail when the products are handled. The most important flow properties are the compressive strength (unconfined yield strength), from which the flowability is determined, the time consolidation (increase in compressive strength with storage time),
the internal friction and the wall friction, the bulk density and the compactibility (compressibility). Although these parameters result from the particle size distribution, the particle shape, the surface properties and the moisture content of your product, there is no direct correlation with which one could draw conclusions about the flow properties from these parameters. Therefore, only measuring devices that directly measure the flow properties are suitable. The ring shear tester can also be used to measure the abrasion sensitivity of granules or pellets, for example, under defined conditions.
Our ring shear tester was developed by the founder of the company, Prof. Dr. Dietmar Schulze developed and is now the internationally most used device for shear analysis next to the RST-XS.s.
Ring Shear Tester RST-XS.s
The ring shear tester RST-XS is a shear tester according to ASTM standard D6773. This is important because shear tester are the only internationally recognized, partially standardized, devices for measuring flow properties.
The RST-XS.s was developed based on the RST-XS series, which has been used successfully in industry and research since 2002. The aim was to be able to offer an even more compact and versatile device. The sample volume is only 3.5 to 70 ml (depending on the shear cell used). This makes the device particularly suitable for the characterization of fine-grained materials.
Which flow properties can be measured?
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flowability ffc
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Compressive strength (unconfined yield strength)
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Time consolidation (increase in consolidation strength with storage time ("caking"))
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Wall friction (friction of the powder e.g. against stainless steel sheet, coatings or linings)
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bulk density and compressibility.
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For comparative measurements, quality control, etc., the flowability ffc, which is calculated from the compressive strength, is the decisive variable.
Our ring shear tester was developed by the founder of the company, Prof. Dr. Dietmar Schulze developed and is now the internationally most used device for shear analysis next to the RST-01.pc.
Lambda-meter
The lambda-meter is a measuring device for determining the stress ratio K. The stress ratio describes the ratio of the stresses in a bulk solid sample that is loaded with a vertical stress. The resulting horizontal stress is then related to the applied vertical stress. The measurement of such stress ratios is measured most accurately with a lambda meter. It was also developed by the company's founders together with Prof. Kwade in the 1990s and quickly found its way into the world of standards. In chapter "C8 Stress ratio" of Eurocode 1 (DIN EN 1991-4) Effects on supporting structures - Part 4: Effects from silos and liquid containers, the stress ratio for the static dimensioning of silos is implemented.
zur aufgelegten vertikalen Spannung gesetzt. Die Messung solcher Spannungsverhältnisse wird am genauesten mit einem Lambdameter durchgeführt. Es wurde ebenfalls von den Gründern des Unternehmens zusammen mit Prof. Kwade in den 90er Jahren entwickelt und fand schnell Einzug in die Normenwelt. In Kapitel „C8 Horizontallastverhältnis“ des Eurocode 1 (DIN EN 1991-4) Einwirkung auf Tragwerke – Teil 4: Einwirkung aus Silos und Flüssigkeitsbehälter ist das Horizontallastverhältnis zur statischen Dimensionierung von Silos implementiert.