Request Quote for Professional Bulk Solids Testing

Depending on laboratory capacity, results of bulk solids testing are available approximately two weeks after sample receipt. Measurements for time consolidation may extend processing time accordingly.

After completion of measurements, we provide results online for you to access, process, and print. Additionally, you receive a cumulative evaluation of results with scatter coefficients, flow function σc(σ₁), evaluation of effective friction angle φ_e(σ), density functions ρ(σ), and wall friction evaluation φ_w(σ). This allows direct integration of results into your further calculations.

For standard-compliant performance of bulk solids measurements, sample material should not exceed 2 mm particle size. Larger particles can impair measurement accuracy and lead to unreliable results. For special applications or materials with larger particles, please contact us directly so we can individually assess measurement feasibility.

Depending on the selection of measurements, approximately 1-2 liters of sample material per specimen is required for a complete bulk solids analysis for technological silo calculation. For simple flowability factor measurements, 0.5 liters is already sufficient. When creating the quote, we provide you with a precise specification of the sample volume based on the selected measurements and the number of samples.

Please ensure that the samples have a representative composition of the entire material to guarantee accurate and reliable results. Please do not send us unnecessarily large quantities of material. All delivered material is homogenized during sample preparation and reduced to the required quantity. Unless otherwise specified, the initial moisture content of the material is maintained for the measurements.

For determining reference stresses, approximate specifications are sufficient for the following points:

• Silo shape: rectangular or round + dimensions/diameter
• Silo shaft height
• Hopper inclination (relative to vertical)
• Hopper height and/or outlet diameter
• Wall material (polished, smooth, rough, etc.)
• Approximate density

To create a technological silo calculation according to DIN EN 1991-4 the following measurements are required:

• Flow function (multiple yield loci at different consolidation stresses)
• Wall friction (wall friction angles and coefficients)
• Bulk and compression density (density change under load)
• Angle of repose
• Optional: Time consolidation (time-dependent flow behavior)

The flowability factor represents a single value at one consolidation stress for material comparisons.
The flow function shows flow behavior over a larger stress range.

For wall friction measurement we need a wall sample according to drawing from you. Standard materials are available in our laboratory on request. The wall samples should have the same surface characteristics as the planned silo material.

All measurements are performed on standardized and certified instruments in our laboratory. The bulk solids measurements for the yield locus, wall friction, compression density, and time consolidation are carried out with standardized shear testers according to ASTM D6682. This ensures reproducible and comparable results.

After performing the measurements, you receive from us a detailed test report with assessment of the physical flow behavior of the material. For the existing silo geometry, we identify possible flow problems and make possible improvement suggestions for prevention. The report contains all relevant parameters and recommendations for practical application.

After completion of all necessary measurements for technological silo design, a calculation tool for silo geometry design and flow profile estimation is additionally available to you. This enables the calculation of stresses and flow conditions in the silo based on common methods: stresses in filling and emptying state, bridging (critical outlet diameter), limit criterion for mass flow vs. funnel flow, load on the discharge device, etc.

You can set the silo geometry and calculation bases yourself and have them calculated automatically. The results serve as a design aid and estimation of the stresses and flow conditions of the bulk solid in the silo. Please note that some calculation methods are based on generally used empirical foundations and the software does not replace engineering silo calculation.