Accessories for Ring Shear Testers RST-XS and RST-XS.s


Generally, Ring Shear Testers RST-XS and RST-XS.s are delivered with a shear cell and a software package, so that different types of tests can be performed with this equipment, namely flowability tests (yield locus tests), and time consolidation tests (caking tests). For special applications, e.g. for time consolidation tests conducted on several specimens simultaneously, for wall friction tests, and for tests with very small powder samples we offer accessories as listed below.


Time consolidation bench

A time consolidation bench serves for the storage of a shear cell with a presonsolidated power specimen. Therewith the storage of a powder under stresses as occurring e.g. in a silo or a container is simulated. For such a test, at first a specimen is consolidated in the ring shear tester, then the shear cell with the specimen is removed from the tester and placed in a time consolidation bench, where it is stored for a defined time period (e.g. one day or one week). The stress is exerted on the specimen through weights. After the consolidation period is over, the powder specimen is sheared again with the ring shear tester in order to measure the strength of the consolidated powder. Thus, one obtains a quantitave result on the increase of strength during the consolidation time, which is known as "caking".  

Time consolidation bench for one cell (with cover)

In principle, the specimen also can be stored on the ring shear tester instead of the time consolidation bench, but in this case only one specimen at once can be investigated, and the ring shear tester cannot be used for other tests during the consolidation period.

The time consolidation bench with cover (type XS-1C, see photograph to the right) serves for the storage of one shear cell. The cover minimizes the contact of the specimen with the ambient atmosphere. The consolidation load is transferred to the powder specimen through a vertical loading rod provided with a disk, on which an appropriate amount of weights is placed.

The time consolidation bench without cover (type XS-1O, see photograph to the left) is provided with a special loading mechanism with counterweight. The counterweight compensates the weight of the loading mechanism, so that small consolidation loads can be exerted on the powder specimen.

The design without cover allows a more intensive contact between the powder specimen and the ambient atmosphere. This is preferable if the behavior of the powder in dependence on the ambient conditions has to be studied, e.g. by storing the time consolidation bench with the shear cell and the powder specimen in a climate chamber.


Shear cells

The ring shear tester RST-XS is generally delivered with one shear cell type XS-Mr. For somewhat coarser powders a larger shear cell, type XS-Lr, is available (data see below).

If only very limited amounts of powder are available for testing, the shear cell types XS-MV4 or XS-SV3 with a specimen volume of only about 9 cm³ or 3.5 cm³, respectively, can be used. Due their small volume, thiese shear cells are especially suited for testing very fine powders.

Overview on the shear cells available:

  • Type XS-Mr (standard shear cell, cross-section ca. 24 cm2, specimen volume ca. 30 cm³, maximum particle size depends on the type of powder and is about 1 mm for broad particle size distributions and 0.5 mm for narrow particles size distributions).
  • Type XS-Lr (larger shear cell, cross-section ca. 46 cm2, specimen volume ca. 70 cm³, maximum particle size depends on the type of powder and is about 1.5 mm for broad particle size distributions and 0.75 mm for narrow particles size distributions).
  • Type XS-MV4 especially suited for small amounts of powder (cross-section ca. 24 cm2, specimen volume ca. 9 cm³, maximum particle size depends on the type of powder and is about 0.5 mm for broad particle size distributions and 0.25 mm for narrow particle size distributions).
  • Type XS-SV3 especially suited for very small amounts of powder (cross-section ca. 13.5 cm2, specimen volume ca. 3.5 cm³, maximum particle size depends on the type of powder and is about 0.3 mm for broad particle size distributions and 0.2 mm for narrow particles size distributions).
  • Type XS-Lr0 "low stress" (larger shear cell with "hanging" lid for Ring Shear Tester RST-XS.s, cross-section about 46 cm2, specimen voluem about 70 cm³, max. particle size depends on the type of powder and is about 1.5 mm for broad particle size distributions and 0.75 mm for narrow particle size distributions)

Material:
Standard: AlMg3 (aluminum), internal parts: 1.4301 (stainless steel).
Optional: 1.4305 (stainless steel), internal parts: 1.4301 (stainless steel).
Other material on request.

Each shear cell consists of a bottom ring, a lid, and a crossbeam attached to the lid.


Wall friction cell

for the measurement of the wall friction angle or coefficient of wall friction (friction between a powder and a wall material). For the test, an annular wall material specimen is to be placed in the shear cell. Wall material specimens can be made by the customer according to dimensions given in the tester's manual..

Size:

  • Type WM (standard, approx. 20 cm³ sample volume, diameter of the wall material specimen: approx. 75 mm),
    Material: AlMg3 (aluminum)

Each shear cell consists of a bottom ring, a lid and spacer disks for the adjustment of the vertical position of the wall material sample.


Weights

For time consolidation tests in combination with the time consolidation bench (see above) weights are required for the adjustment of the consolidation load.

Available sizes:
2 kg, 1 kg, 0.5 kg, 0.2 kg, 0.1 kg.
Accuracy: min. +/- 1%
Dimensions: thickness 10 mm to 14 mm, dimensions depend on weight.
Material: nickel plated mild steel, or brass.

Weights are available as set or separately.


HOME - www.dietmar-schulze.de

Technical modifications excepted.
© 1996-2014 Dietmar Schulze. All rights reserved.
Last updated: August 27, 2014.