Thursday, 30 June 2016

Chemical Process Plant Layout

 

I uploaded my new book on process plant layout to the publisher's website yesterday. It's three times as big as my first one on process and plant design, and it was quite a job of project management to make sure it was complete, current and correct with respect to consensus professional design practice. It also required the assistance of hundreds of plant layout designers. I am grateful to everyone who helped make the book a reality.

The book is an update of Mecklenburgh's Process Plant Layout from the 80's, and the table of contents of the new version goes like this:

CONTENTS
Dedication
Acknowledgements
Part I. GENERAL PRINCIPLES
1              Introduction
2              Layout in context
3              Site layout principles
4              Plot layout principles
5              Planning of layout activities
6              Methods for layout, conception and development
7              Layout analogues and visual aids
8              Hazard assessment of plant layout
Part II. DETAILED SITE AND PLOT LAYOUT
9              Transportation
10           Bulk Fluid storage
11           Bulk solids storage
12           Warehouse storage
13           Pollution Control
14           Utilities I : General
15           Utilities II : Water and Steam
16           Central services
17           Construction and layout
18           Details of plot layout
19           Layout within buildings
Part III. DETAILED LAYOUT OF EQUIPMENT
20           Tanks and Drums
21           Furnaces and fired equipment
22           Distillation columns and towers
23           Heat exchangers
24           Reactors
25           Mixers
26           Filters
27           Centrifuges
28           Solids handling plant
29           Dryers
30           Filling and packaging
PART IV: Detailed Layout: Materials Transfer Systems
31           Pumps
32           Compressors
33           Conveyors
34           Piping
PART V: Detailed Layout: Other
35           Pipe Stress Analysis
36           Instrumentation
Part VI APPENDICES       
A             CAD
B             Hazard assessment calculations
C             Typical data for preliminary layouts
D             Variants on the methodology
E              Masterplanning
F              Conversion factors for some common units
G             Consolidated Terminology / Glossary
H             Consolidated Standards and Codes of Practice

Managing the content of these thirty-six chapters and eight appendixes, such that all were in agreement and cross-referenced was a major task, as was updating and adding hundreds of illustrations, and seventy five case studies to illustrate the consequences of not following best practice.  

The book which was uploaded was my revision 9. My next book will not be such a logistical challenge, but I might be up for producing another tome like Process Plant Layout after that.

Friday, 24 June 2016

The Voice of Chemical Engineering

I love to write. As well as the technical and expert witness reports which are so much of my professional practice at this stage of my career, my second textbook is about to be submitted to the publishers, and I do a lot of blogging to keep the writing muscles limber. For anyone who has never read my "Voice of Chemical Engineering" blogs for Elsevier, you can see them here. There are also my posts on LinkedIn, as well of those on "Expertise Unlimited". I am also currently writing articles for "Chemical Engineering", "Chemical Engineering Practice", and "Engineering and Technology Reference" magazines, and a piece on Reactor Selection and Design for Ullmanns Encyclopaedia of Chemical Technology. I also have a research paper on my teaching practice at Nottingham to write up. Oh, and a PhD. Luckily I write quickly...

Friday, 17 June 2016

Water Engineering Expertise : Evaluation of Management of the Process of Water and Sewage Plant Design and Operation

Though both are covered by confidentiality agreements, all my current expert witness engagements are to do with my evaluation of management of the process of process plant design and operation. This is the most common area on which I offer expert evidence.

There are a number of ways in which process design can go wrong. The best way to ensure it goes wrong seems in my experience to decide to dispense with the process engineer completely - they are after all expensive(but not, it turns out, as expensive as deciding to do without therm)

The second best is to assume that anyone with a degree in engineering is an engineer. Green engineering grads are not engineers yet. They require close supervision by a proper engineer. They may be cheaper than proper engineers, but this often proves a false economy.

The third best is to be unsure of who is responsible for process design. This either shades into the first example, or comes down to bad paperwork.

The fourth is to fail to manage the design process. Active management and formal quality control is required to produce a good design.

The fifth is to fail to manage the construction and commissioning process. Active management and formal quality control is also required to build a good plant .

The sixth is to fail to manage operation and maintenance properly. Operators are human, and left to their own devices, do what is easiest. I see a lot of dusty O+M manuals on site visits, unopened since the day the plant was started up.

To really screw things up usually requires a combination of these approaches. Figuring out which were responsible for plant failure is a fascinating task.  

Friday, 10 June 2016

Process Plant Layout Engineering

Process Vessel Harburg Docks
















I am putting the final polish on my Process Plant layout book, (now available for pre-order). My submission deadline is the end of the month, and though the book has been finished for some time, it is always possible to check and tweak and make a book just a little bit better.

Here's an image that didn't make it into this edition of a process vessel in Harburg, Germany. Sometimes blending in to the environment is not the way to go. This giant minion positively enhances an ugly industrial area by the docks.

Friday, 3 June 2016

Expert Witness Water Process Engineering: Data Analysis

Things are progressing with my latest expert witness report. I'm producing a Part 35 compliant report alongside analysing a mass of data about the operation of a tertiary sewage treatment plant.

Expert witness work of the kind I do often involves process troubleshooting. There can be no proper process troubleshooting without stats. I have never had to carry out a three way ANOVA with interactions or use Duncan's multiple range test professionally, but if you have tens of thousands of data points, plotting them on a scatter diagram isn't going to tell you much.

At a minimum you are going to need to use summary statistics to make some sense of the data. Using MS Excel to show you the mean, minimum, maximum, and the upper limits of the 95% confidence interval of your dataset is a good place to start. You might generate correlation coefficients for relationship between parameters.

In some posts here and elsewhere I have criticised the kind of mathematics taught on chemical engineering courses for being too "pure", and insufficiently relevant to modern practice. Some have interpreted this as me saying no maths should be taught, and refuting that quite different idea, what is known in philosophy as a "straw man" fallacy.

I find people who cannot find an valid argument to counter what I am saying frequently wish to discuss what I am almost implying, what they feel about what I am saying, or something I am not saying at all. So, in the interests of clarity, I am saying that maths is good, necessary and useful to the practising engineer. Laplace transforms may not be of much use, but stats are essential. It is a pity that university curricula view things the opposite way around.

I could teach my twelve year old to get Excel to produce summary statistics in fifteen minutes. What an expert offers is not the knowledge of how to do this, but an understanding of what the results mean and what they do not mean. It is commonplace even amongst supposed experts to misunderstand what we are 95% confident about within the 95% confidence interval, to never check whether the assumptions underlying the valid use of parametric statistics are true, and to be unaware of when and how to apply non-parametric statistics.

If you were to hire a statistician, they would hopefully understand all of the above better than I do. They would not however understand what the outputs mean because these are not just numbers. These are clues as to the state of a process. Chemical/ process engineers understand processes. Maths is just a tool to help them see more clearly, and inform their answer to the questions they are being asked. These questions usually add up to the same thing. "How well does this process work?"

The answer to this question is often "It doesn't", and then we sometimes get back to those discussion of what I am almost implying, what they feel about what I am saying, or something I am not saying at all. I'm pretty sure these arguments do not impress courts any more than they impress me.