Looking for an older Powder Perspectives by Joe Marinelli? Find it here.
Column 1 - Published June 13, 2013
Factors That Impact a Powder’s Flowability
Moisture content, temperature, particle size, and time of storage at rest can have a tremendous impact on your material's flow properties. How your material flows is a function of its cohesive properties. As such, conditions that affect the cohesive strength of a powder will have an impact on its handling capabilities. Read the rest of the story here
Column 2 - Published June 24, 2013
Powder Perspectives: There is a Science to Powder Handling
The field of solids handling was developed mainly through the work of Dr. Andrew W. Jenike, who pioneered bulk solids flow theory. Dr. Jenike developed a scientific approach to the storage and flow of bulk solids in the 1950s that is still relevant today. In fact, the Jenike shear test is now the ASTM standard (1) in the United States and Europe for determining bulk solids’ cohesive and wall friction properties. Read the rest of the story here
When Things Go Wrong: How to Address a Solids Flow Problem
As a consultant to the bulk solids handling industry for so many years, I have been involved in numerous approaches to solids handling problems. The process usually starts problem. This typically results in the submission of a with a telephone conversation concerning a particular proposal for material testing and conceptual design recommendations. Read the rest of the story here
Column 4 - Published July 29, 2013
Storage Silo Selection for Dry Bulk Applications
The process of silo selection starts with a series of questions that require answers before proceeding. This is one of the main problems witnessed in today’s dry bulk storage market. Tank and silo selection many times is based on a preferred “construction type” in lieu of “stored material” performance requirements. Read the rest of the story here
Column 5 - Published September 5, 2013
Frequently Asked Questions - Part 1
Having been a consultant for many years, I have obviously been asked some of the same questions concerning solids flow, time and time again. Here are some more frequently asked questions and answers. 1. How can bulk solids flood or flush out of a bin? Read the rest of the story here
Column 6 - Published November 6, 2013
Handling Carbon Black and Titanium Dioxide
Carbon black and titanium dioxide (TiO2) are two of the most difficult powders to handle in bins, hoppers, and feeders. You may conclude that, as the title of this article indicates, designing a handling system for these "nasty" materials is not black and white. If you are not familiar with TiO2, it is a fine white powder that provides whiteness and opacity to paints, coatings, plastics, paper, inks, fibers and food and cosmetics.? Read the rest of the story here
Column 7 - Published January 10, 2014
Addressing Segregation Problems
This article discusses two major mechanisms of segregation; namely, sifting and fluidization segregation.
What is sifting segregation?
Sifting segregation occurs when small, fine particles move through large, coarser particles. This is the most common means for particles to separate. In order for sifting to occur, they material must be:
Column 8 - Published January 30, 2014
How to Interpret a Solids Flow ReportIn order to determine if a new bin or silo will work reliably, or to be able to make modifications to an existing troublesome bin or silo, you need to know:
· What type of flow pattern can develop (modes of flow)
· Your material’s flow properties Read the rest of the story here
Column 9 - Published March 18, 2014
The State of the Powder Handling Industry
This article is more of an editorial on the state of our powder handing industry. I presented this topic at the Powder Show in Houston in October of 2013, and would like to repeat some of the relevant topics here.
Column 10 - Published May 20, 2014
A Perspective on the Powder Show
I have been attending the Powder Show in Rosemont, IL since 1978. This year's show was much more upbeat than years past, as the show seemed to have gotten somewhat stale. UBM and Powder & Bulk Solids have made significant improvements to the venue.
Column 11 - Published May 22, 2014
Loading Materials via an Aeromechanical Conveying System
A properly designed aeromechanical conveyor system is a proven machine. It was invented in 1959, specifically for the purpose of conveying peanut halves. Since then, it has broadened its ability to convey all types of flakes, granules, and powders in a dust-contained and hygienic manner. It is the rope assembly's speed that allows the versatility of all dry bulk solid materials to convey through the machine.
Column 12 - Published June 24, 2014
Combustible Dust Basics: How to Collect a Sample and What Does a Go/No-Go Test Mean?
We’ve been writing a lot recently on the basics of combustible dust. Makes sense, after all, what safety professional knows exactly how much of their particular dust, in their particular facility under a certain set of circumstances is ok? Read the rest of the story here
Column 13 - Published July 21, 2014
Should My Material Be Tested On-Site?
In the past, we have discussed flow properties testing and the need for this type work to ensure reliable bin and hopper flow. The Jenike Shear Tester is a device that is recognized as the standard for testing bulk solids by ASTM (D-6128-97) in the U.S. and in Europe, and the test procedure is well adapted for a testing laboratory.? Read the rest of the story here
Column 14 - Published September 2, 2014
Factors That Impact a Bulk Solids Flowability
When handling bulk solids, there are several factors that can affect your material flow. Most of these are environmental; all of them need to be taken into consideration. Read the rest of the story here
Column 15 - Published January 22, 2015
How to Design a Belt Feeder Interface
I would like to begin the new year with an article on belt feeder design. In this article, we discuss proper belt feeder design technique so as to maintain reliable flow from bins and hoppers. Belt feeders are used to feed many types of bulk solids. Read the rest of the story here. Read the rest of the story here
Column 16 - Published August 3, 2015
How Wall Friction Affects Hopper Angles
Measuring a bulk solid's wall friction is critical to ensuring reliable flow. The wall friction angle for a given bulk material/wall surface combination is calculated from the results of a wall friction test. Read the rest of the story here