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John Marriott Smith, who died 28th March 2015 - Memories of a friend and colleague

by Alvin Nienow, Birmingham, 12th April 2015

I first met John at a conference in Montreal in 1968. It was a Tripartite Chemical Engineering Conference organised by AIChE, CanSocChE and IChemE. It was a memorable day because it was my first meeting of many with John around the world. It was also memorable for me, and perhaps for him too, because it was the only time that I met Professor P V Danckwerts, who was chairman of the mixing session in which we both were presenting. Our chairman was on that occasion notable for being singularly taciturn. My lecture concerned particle suspension and solid liquid mass transfer and John’s was on high viscosity mixing with anchor impellers, from his first academic post in Swansea and co-authored with Colin Peters. Both were subsequently published in the Canadian Journal.

Later, John moved as professor to the prestigious Kramers Chair of Physical Technology at Delft University of Technology where initially he further developed his interest in high viscosity and non-Newtonian mixing and he published a significant amount of work on screw extrusion with Leon Jannsen (who later became a leader in that type of processing with a chair in Groningen). In 1974, we also both attended the First European Conference on Mixing and Centrifugal Separation (my italics-the reason for these strange bedfellows was because the venture was a commercial one by the BHRA conference section and the business leader of that section figured that as both involved rotating bodies, they could usefully be put together, thereby increasing the likely attendance!).  By that time, John was working with Klaas van’t Riet and his paper discussed the trailing vortex of the Rushton turbine, a precursor to the 1975 CES article which was chosen as one of the 21 most influential by NAMF. Later, van’t Riet went on to write one of the best biochemical engineering books, Basic Bioreactor Design, perhaps the only one on the topic which properly recognises the critical role of mixing in bioprocessing.

In January 1975, he invited me to a meeting of the European Federation of Chemical Engineers Working Party on Non-Newtonian Processing at the Technical University of Twente when it had only just opened. It had superb buildings but only about half were occupied; a good example of Dutch forward thinking, with Twente now being a leading player in Dutch technical education. Though the meeting was about non-Newtonian Processing and all talks but mine were about laminar flow, John was using it to try to get a WP on mixing established. He finally succeeded in Mons in 1978 when the EFCEWP on Mixing was established and he became the Dutch delegate. Later, he became the first recipient of the BHRG Prize for his ‘Lifetime Contribution to Mixing Research and Practice’.

In 1983, the industrial consortium, Fluid Mixing Processes (FMP), run by BHRA (now BHRGroup) was established. John was heavily involved advising BHRA on the best structure for the consortium and acted as a consultant to it for many years. It is still going strong with a structure which has grown organically based on the initial one, so it seems the advice was good. In 1989, he and I were the only Europeans to be invited to a meeting in Maryland out of which the decision to establish the North American Mixing Forum (NAMF) grew. NAMF has had a major impact on bringing together, at the many mixing conferences that it organises, academics and industrialist from the US and the rest of the world with an interest in mixing; and it has gone from strength to strength.

Around 1992, John moved back to the UK to a Chair in the Department of Chemical Engineering at the University of Surrey linked to biotechnology. The ‘bio’ never really caught on with him. As he said, for a man interested in rock crystals and fossils (and especially searching for them in quarries wherever and whenever he could), it didn’t seem appropriate. Instead, he established a new area of research based on his earlier great success in gas-liquid mixing, namely mixing in boiling and hot gassed reactors. Until he started, though highly-important and industrially-relevant, it was a little-researched. Again, he published key papers on this, many with ‘Bruce’ Gao from Beijing; and Professor Gao and his team are still continuing studying the phenomena.

From 1983 to about 2011, John also participated in two mixing courses annually, one in Sweden and one in the US with me and Mike Edwards (who was replaced in the late 1980s by Art Etchells when Mike moved from Bradford University to Unilever). With occasional in-house courses during that period too, we ‘taught’ some 800 students over the years, including Jim Oldshue, Julian Fasano and Suzanne Kresta! He loved to introduce joke slides into his lectures from prints in his collection of old books, mostly on technology: one from 1851 of a large multiple paddle mixer driven by a single horse to which he gave the title, ‘1 HP per 1000 US gallons’; another of Stonehenge, which somehow became part of an early rotor-stator mixer. One of the courses was held at the Fort Lauderdale Marriott and on registering, they commented on his middle name being Marriott. They were sufficiently impressed that the next day, they placed a bowl of fruit and a bottle of wine in his room with the compliments of the hotel!

It was during the evenings on these courses that I got to know him best, especially in snug bars on cold winters nights in Sweden and at the outdoor pool bar on balmy ones in Florida! In addition to his beautifully-presented rock and fossil collection at his house, he loved good wine, food and conversation; old technical books, classical music and rugby; and was proud of his Welsh background. In the summer of 1984, I also spent about a month with my wife Helen house-sitting in Delft for him and his wife Joyce while they were away in Buffalo with Jarda Ulbrecht. Our main task, carried out by Helen, was to ensure that the cat took its tablets each day. By carefully wrapping it in the cat’s favourite food, the tablets got taken and Helen escaped with only minor bites and scratches!

John made a major impact on the ubiquitous chemical engineering unit operation of mixing, especially his research related to gas-liquid and boiling reactors; and in the development of the infrastructure that supports academic-industrial collaboration. His work was recognised by the EFChEWP on Mixing by making him the first recipient of its Lifetime Award; and many of his co-workers are still continuing to move the field forward. He was a good friend to many, particularly in the UK, in Europe (and especially Holland) and in the US and his company was always sought at the many conferences that he attended, often by invitation.  He will be greatly missed.

A ‘Mixer of Mixers’ at Ramesh‎ Hemrajani’s House in New Jersey During a CfPA Mixing Course; An Evening, Nov 2007 (l. to r.; John Smith, Alvin Nienow, Ramesh, Brian Johnson, Art Etchells, Ed Paul)

John Smith & his contribution to mixing and life

by Suzanne Kresta

John was a mentor and friend to many in the mixing community, and to his colleagues at Delft University of Technology, University of Swansea, and University of Surrey. He made very significant contributions to the gas-liquid mixing literature, with important and quite different chapters in both Harnby, Edwards and Nienow, and in the Handbook of Industrial Mixing. These cornerstone chapters remain the major reference points for design of gas-liquid mixing equipment. His paper with van't Riet on the trailing vortices associated with Rushton turbines was a landmark contribution listed in the 21 Most Significant Contributions to Mixing Literature in 2011. While at the University of Swansea, he was involved with an early edition of the classic series of chemical engineering texts by Coulson and Richardson (first edition, 1971).

John loved classical music and hiking (walking) in the hills of southern England, and at many NAMF conferences over the years. His beloved collection of old technical books yielded a number of images of ancient mixing equipment, which he shared with the community over the years. He had warm and loving relationships with three wives, and is survived by a son and a daughter, Ralph Smith and Andrea Dimbleby. He had been suffering from cancer for a long time, but kept up correspondence with a number of colleagues and was always responsive to questions about his earlier work.

John Smith

by Piero M. Armenante

I am deeply saddened by John’s passing.  He was actually the person who, literally, first introduced me to mixing, and with long-lasting and significant consequences for the rest of my professional life.  Back in the spring of 1980, I was in my second semester of graduate school at the University of Virginia, and John was Visiting Professor at UVa for just that semester.  It so happened that during that semester he offered a graduate course in mixing and I decided to take it, not knowing exactly what it was about (I still have the course notes somewhere in my basement).  Only four Ph.D. students took it and I was one of them.  Clearly I enjoyed the course, and at the end of that semester I decided to change project and advisor, and I started working on mass transfer in stirred vessels with Don Kirwan and Elmer Gaden.  I guess that John’s course played a critical role in my decision, not to mention my future professional career.  We met again only several years later at my first (European) mixing conference in Würzburg.  From that time on, we met often, especially at mixing conferences on both sides of the ocean, but, as it often happens, I do not think that ever mentioned to him how significant he and the course that he taught a long time ago were for my future academic life.  And this is why I now feel compelled to share this with you now.
P.S.  He gave me an A-.