Monthly Archives: March 2014

A Bench-top Reactor Designed for the Researcher’s Needs

Synthetic hydrocarbons, generated by the Fischer-Tropsch reaction, are commonly used as fuels and lubricants.  In the F-T reaction, syngas (a mixture of carbon monoxide (CO) and hydrogen (H2)) flows into a reactor loaded with a cobalt, iron, or nickel catalyst.  The products are the liquid hydrocarbon and water.  This process is typically done in a large scale reactor and requires a separation mechanism to remove the water.  Now, the Particulate Systems Microactivity Effi and its patented liquid/liquid/gas separator brings this reaction to the bench-top. Continue reading

Measuring Particle Size Average or “Fisher number” of Metal Powders

Metal powders are used in a wide variety of applications.  Many of the items we use on a daily basis include parts molded using metal powders.  One parameter to control the quality of the metal powders is particle or powder size, typically in the form of an average value or “Fisher number.” 

A common metal powder sizing technique is by air-permeability which gives an average size.  Traditionally, a Fisher Model 95 Sub-Sieve Sizer (FSSS), with a particle size range of 0.5 to 50 µm, has been used to get this average size value, or “Fisher number.”  Using this technique is the basis for ASTM Standard B330-12, “Standard Test Methods for Estimating Average Particle Size of Metal Powders and Related Compounds Using Air Permeability” as well.  Since the FSSS has been discontinued, industry has been clamoring to find an alternative to technique or device that gives the same results and agrees with all the historical data collected on the FSSS.

HEL’s Subsieve AutoSizer (SAS) distributed by Particulate Systems, a Micromeritics Brand, is now available to Continue reading