Sometimes progress occurs so slowly that it appears that nothing is changing. Looking back over the last two decades, it is clear that the importance of characterizing and using the flow properties of bulk solids in design is becoming mainstream.
Twenty years ago I joined a group of industry professionals and consulting engineers to form an ASTM subcommittee to address issues involving powders and bulk solids. The subcommittee, titled D18.24 “Characterization and handling of powders and bulk solids”, has to date produced ten ASTM Standards. Their (abbreviated) titles are shown below:
- D6128 “Shear testing using the Jenike Shear Cell”
- D6393 “Characterization by Carr Indices”
- D6682 “Measurements using the Peschl Rotational Split Level Shear Tester”
- D6683 “Measuring bulk density values of powders and other bulk solids”
- D6773 “Shear testing using Schulze Ring Shear Tester”
- D6940 “Measuring sifting segregation tendencies of bulk solids”
- D6941 “Measuring fluidization segregation tendencies of powders”
- D7481 “Determining loose and tapped bulk densities of powders using a graduated cylinder”
- D7743 “Measuring the minimum fluidization velocities of free flowing powders”
- D7891 “Shear testing of powders using the Freeman Technology FT4 Powder Rheometer Shear Cell”
I have had the honor of chairing this subcommittee since 2007.
We are currently working on several new standards, one of which involves an effort to develop a procedure for a test method to determine entrainment and saltation velocities in dilute phase conveying using small-scale equipment. This is a challenging task, since duplicating full-scale conditions in lab-scale or small-scale equipment with a small quantity of powder poses unique and difficult challenges.
We are also exploring developing standards on deaeration of powders, jet cup attrition, and others.
The ASTM process provides a forum for discussion amongst practitioners and experts in the field, and develops consensus standards that reflect practical experience and proven methods. If you have an interest in joining or would simply like more information, please feel free to contact me at firstname.lastname@example.org.