Honoring a Bulk Solids Pioneer
We have all heard of Man of the Year awards, but this one is different. In recognition of outstanding contributions that transformed the storage and handling of bulk solids from an empirical industry to a science, the British Materials Handling Board recently honored Andrew Jenike, Ph.D., as the leading Bulk Technology Pioneer of the Twentieth Century at the American Institute for Chemical Engineers Annual Meeting in Salt Lake City, Utah. Jenike is one of the true pioneers in the field of powder and bulk engineering, which has numerous applications in the ceramic industry and beyond.
BackgroundAndrew Jenike was born in Poland in 1914 and graduated in 1939 from Warsaw Polytechnic Institute with a bachelor’s of science degree in mechanical engineering. After graduation, he entered the Polish Army and served with distinction as an officer in World War II. Soon after he entered the army, Poland was overrun by the Nazis and the Russians.
One day, Jenike found himself at the top of a hill. Advancing on one side of the hill were the Nazis, while the Russians made their approach on the other side of the hill. His unit commander said it was time to leave, so Jenike fled on foot through Eastern Europe and eventually made it to England. He found employment there and attended the University of London, where he received his doctorate in structural engineering in 1949.
While in England, he also met and married a British woman named Una. The couple immigrated to Canada and then to the U.S., eventually settling in Salt Lake City. Along the way, Jenike worked for several engineering design firms as a mechanical and structural engineer. Two sons, Michael and Ian, were born during this time.
On April 16, 1953 (his 39th birthday), Jenike made his decision. The topic he chose was the design of bins and hoppers for the storage and flow of bulk solids. Up to that time, the design of this equipment was mostly a black art. Most hoppers were either 45º or 60º, simply because those were the measurements of common triangles that all engineers carried around with them. No one gave much thought to the material being stored.
Once Jenike made his decision, he promptly threw away box after box that he had collected on the other topics he had considered. He wanted nothing to interfere with his decision, no looking back. (It is interesting to note that one of the topics that didn’t make his cut was computing.)
One key contributor to Jenike’s success in developing the basic theories of solids flow came from an unlikely source. While on a trip back to his native Poland, he came across a Polish translation of Sokolovskii’s now-famous Statics of Soil Media. At the time, this book had just been published in Russian and had not yet been translated into English. Jenike immediately recognized that Sokolovskii’s concept that soil stress could vary directly in proportion to the distance from a point fit nicely with some crude bin pressure measurements that he had conducted using water-filled diaphragms. This gave rise to his Radial Stress Field concept.
During his period at the University of Utah, Jenike had a number of graduate students working for him, including Jerry Johanson. In 1962, Johanson finished his doctorate and went to work at U.S. Steel Research. Jenike decided that the time had come to enter full-time consulting, and he moved his family to Winchester, Mass. Four years later, Johanson joined him and they formed Jenike & Johanson. Jenike was president of the firm until he retired in 1979. After that time, he conducted research for about eight years until a serious automobile accident prevented him from working.
Contributions to IndustryThe contributions of Andrew Jenike in filling the void in our understanding of the rheology of particulate solids in gravity flow were thorough and comprehensive. His first important step was to recognize that the inability to predict the design requirements for bulk storage containers that would discharge reliably was a handicap of immense importance to all industries that handle bulk solids, including ceramics, chemical processing, mining, food and more. Applying himself to solving this puzzle, Jenike produced a theory of converging flow that represented the key parameters and process conditions.
He next developed an instrument with which to quantify the relevant factors of a given product, and then constructed a design methodology to interpret these values and produce a geometry for a bulk storage vessel that would guarantee flow and discharge the contents reliably. His pioneering work, published in “Bulletin 123 of the Utah Experimental Station” in 1964, remains the most quoted reference of all papers published in the field of bulk technology and solids rheology.
Andrew Jenike was a visionary and, indisputably, the founder of the modern theories and industrial applications of bulk solids handling. He developed a theory to fulfill a practical need, and he approached his work with enthusiasm and focus. He changed the way we design and build storage and processing vessels for bulk solids in a very revolutionary way-from an empirical technique to a formal engineering procedure with a predictable outcome. The applications of his work go well beyond small bin designs to include bottom reclaim stockpiles, mammoth silos, purge columns, moving bed reactors, in-bin blenders and more.
Thousands of silos have been built based on Jenike’s method of design, and this has improved the economy of industry by perhaps the order of billions of dollars every year worldwide. He has made a deep impact on our understanding of how particular solids behave during flow, and our understanding of silo flow has been changed forever.
In the glass and ceramic industries, Jenike’s approaches have influenced the design and effectiveness of solids handling and batch preparation facilities throughout the world. Engineering firms have adopted design strategies for fine and cohesive powders to achieve reliable flow. Equipment manufacturers have benefited through the inclusion of features that minimize problems while delivering the desired throughput. Even when problems have arisen at operating facilities, such as a loss of batch homogeneity or furnace feed reliability, Jenike’s strategies have been deployed as modifications to help systems realize their economic potential.
Making a Difference“Some advances are made by serendipity, but the more radical improvements usually come about by dedicated study, based upon insight and a fundamental analysis of the underlying factors,” said Lyn Bates, director of the British Materials Handling Board in a tribute accompanying the naming of Andrew Jenike as the leading Bulk Technology Pioneer of the Twentieth Century. “The result of Jenike’s outstanding work was to change the design of bulk storage hoppers, silos, and other storage and processing vessels from an empirical technique to a formal engineering procedure with a predictable outcome.”
Fundamental phenomena like mass and funnel flow were bound to be discovered sooner or later by someone equipped to make the necessary observations. However, it was Andrew Jenike who first made the discovery, and he formulated vital theories in his own practical way. He initiated a completely new field of research that will continue to challenge new generations of scientists for many years to come.
For more information, contact Jenike & Johanson, Inc. at 400 Business Park Dr., Tyngsboro, MA 01879; (978) 649-3300; fax (978) 649-3399; e-mail the authors at firstname.lastname@example.org or email@example.com; or visit www.jenike.com.