Contribute to a Holistic Approach to Unit Operations!

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As the chemical industry changes and becomes more integrated worldwide, there is a need for information exchange. This must include not only principles of operation but practical knowledge transfer. That’s why I have agreed to edit a new book for Elsevier, “Integration and Optimization of Unit Operations.”

As my readers know, in 2015, I published the “Handbook of Solid-Liquid Filtration” with Elsevier, UK. This new project offers up-to-date and practical information on chemical unit operations from the R & D stage to scale-up and demonstration to commercialization and optimization.  

For this exciting and unique book to work, I need your help. I’m currently seeking contributing authors who have skills at each stage of the process from lab-scale/R&D, through pilot plants to full-scale production and finally optimization or as I call it, Putting-It-All-Together, for actual case histories / war stories.  We will also cover decommissioning of plants. Check out the preliminary Table of Contents.

Currently, most books look unit operations, each in a silo.  In this book, at each stage, the information presented differs as the technology and issues faced at the lab scale differ through commercialization and optimization. So, we will move from a silo approach to an integrated – holistic approach.

Why this Book is Needed

This book addresses a need for engineers with a broader training background. In the early 70’s, companies wanted staff with an I-shaped skill level. Someone with I-Shaped Skills is a person with a deep (vertical) expertise in one area and practically no experience or knowledge in other areas. This person is typically known as a specialist.  

Then, in the 1980s, the industry wanted T-shaped professionals. The vertical bar on the T represents strong knowledge in a specific discipline. The horizontal bar represents a wide (horizontal) yet shallow knowledge in other areas. This allows the person to be able to collaborate across other disciplines and acquire new skills or knowledge. 

Yet what we need today, with the rapid proliferation of technological advances and the cross- disciplinary nature of our work, is key-shaped engineers who can address several areas of expertise with varying degrees of depth.  

This book aims to address the needs of engineers who want to increase their skill levels in various disciplines so that they are able to develop, commercialize and optimize processes. The engineers must be able to ask questions of experts to develop creative solutions.

What Can You Contribute?

Contributing authors should be able to discuss unit operations at each stage and then relate how these technology/process decisions impacts the next stage. I am targeting the first draft by the end of the year. I will provide technical guidance and assistance as well as from my associate who is skilled in technical writing along with the Elsevier requirements.

The book will be listed on ScienceDirect, Elsevier and others and chapters will receive individual indexing so they can be searched. Review the preliminary Table of Contents and let me know what interests you to write about!

I hope you’re as excited about this opportunity to share knowledge about unit operations as I am! I look forward to hearing from you.

Dryer Selection and Bulk Solids Handling 

 

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Image source: https://www.toolshero.com/decision-making/blindspot-analysis/

Solids handling is not a unit operation. Therefore, it’s not covered in engineering courses. This leaves process engineers struggling to understand the “flowability” of bulk solids. This blind spot is huge. So, let’s talk about dryer selection and bulk solids handling.

Recently in The Chemical Engineer, Grant Wellwood described bulk solids handling as the biggest industrial activity on the planet. The article estimated “that >70% of everything we use or consume involves bulk solids handling somewhere in its lifecycle.”

Mishandled, this process can quickly and efficiently destroy product value, careers, projects and even organizations. Yet, bulk solids flow is often an afterthought once the separation and drying equipment is selected. This article aims to bring bulk solids handling to the forefront.

Bulk Solids Handling Parameters

Bulk solids are defined as materials (solids) handled in various volumes and counts. Their flowability is impacted or controlled by friction (particle-particle or particle-surface). During the drying process, solids go through different phases such as free moisture, bound moisture, thixotropic and finally (and hopefully) free flowing.  

The selected dryer must be able to handle each phase without creating fines, balls that can trap liquids, and without adding additional heat due to friction.  

Here are some of the process and design parameters engineers need to consider for dryer selection:

  • Dryer Process: Batch, Continuous, Atmospheric/ Vacuum, Turbulent, Gentle, Ring-Layer, Feeding  (Volumetric or Gravimetric), Upstream and Downstream Equipment
  • Recipes: Number of ingredients, Frequency of campaigns, Cleaning operations, Product integrity (fines generation) after drying and  Residence time
  • Dryer Performance: Batch size, Filling levels, and  Production volume
  • Product Characteristics: Quality, Bulk density, Tendency of segregation & agglomeration, Thixotropic phase, Shape, Size, Homogeneity, Risk of separation, Flow properties, Abrasiveness, and Moisture & Temperature
  • Mixer design: Material of construction,  Surface quality, Heating/cooling, Liquid feeding, Type of mixing tools, Speed of mixing tools and degree of back mixing
  • Dryer Integration: Material flow, Physical space, Process sampling, safety requirements, etc.

It’s a lot to think about. Westwood observed in his thorough article, “When handling bulk solids, it’s always important to take a holistic or systems view because of the complex dependencies.”

BHS & Bulk Solids Handling

As my readers know, BHS provides for thin-cake filtration, cake washing and dewatering based upon pressure or vacuum, for batch or continuous operations from high solids slurries to clarification applications with solids to 1% and trace amounts.  

In 2018, BHS acquired AVA mixers and dryers based in Herrsching (Munich) Germany.  VA is in the unique position to provide both vertical and horizontal technologies providing for turbulent as well as gentle mixing, reacting and drying of wet cakes, powders and process slurries. The technologies are vacuum or atmospheric, batch and continuous, for final drying to “bone-dry” powders. The BHS technical article, Dryer Selection, explains the designs as well as selection parameters.  

We know that solids change when processed from a wet-cake to bone-dry powder. Process engineers need to do the tests and trial and error to better understand these changes. As I often say, we can’t jump to conclusions.

Our process engineers would be happy to help at the BHS test center. With an understanding of how the flow properties change, depending on “complex interactions between particle size and distribution, moisture content and distribution, process history (time and manner), mineral composition, surface texture and condition as well as ambient conditions, just to name a few…” the dryer selection can begin in an educated manner. 

Good luck and feel free to contact me for help with your bulk solids handling questions.