Flow Measurement and Instrumentation: Critical Components for Sustainable Processes

Flow Measurement and Instrumentation: Critical Components for Sustainable Processes

This post was written by Gregory M. Gomez, vice president of flow instrumentation for Badger Meter.

Consumers, industry, and society in general benefit from a commitment to sustainability. This concept is not purely about conservation or “being green.” Sustainability is not about using less, but about using the right or necessary amount—reducing waste in the process. The value of sustainability as a business opportunity is balanced between altruistic ideas related to protecting the environment and the very practical economic drivers of maximizing process efficiency and revenue. In fact, research indicates that both business and consumers in the mainstream prioritize the related economic benefits of sustainability and view leaving a better environmental footprint as an important bonus. With process efficiency as the goal, cost savings, increased profits, customer goodwill, and yes, environmental benefits, result.

 

Flow measurement and instrumentation are critical components for making usage visible to manage sustainable processes and operations. The hospitality industry is a great example. It is common to see a card on the bathroom sink that asks us to conserve resources by hanging our towel back on the bar. Intuitively it is clear to us that less laundry is less water used by the hotel, but by how much exactly? It is difficult to manage what is not measured. Without an understanding of the true benefits of making the change, actually significantly decreasing water use is difficult.

Using flowmeters and analytics platforms available today, hotel management can make water use much more visible than a single line item on the water bill. Employing near-real-time data and analytics dashboards, management is able to truly see and manage water use across a variety of aspects of its operations (e.g., guest rooms, laundry, bars/restaurants, golf courses, other irrigation, industrial, process operations). The sign will be much more effective at influencing our behavior when the hotel can associate a specific percentage of water actually saved with hanging up the towel. This also produces a related savings in energy, supplies, and labor hours to the hotel. Plus, there is a public relations benefit to the guest who is interested in conserving water.

Accurate and reliable flow measurement and instrumentation directly lead to more efficient use of our precious, often expensive resources, and in turn, benefit the bottom line. More and more corporations see sustainability as a business opportunity, both in terms of maximizing efficiency and attracting “green-minded” customers.

The concept of sustainability has obvious ties to the efficient use of potable water, and it also relates to virtually any commercial or industrial process, including oil and gas production. The increasing use of water in unconventional production processes, like hydraulic fracturing, competes with the need for drinking water and irrigation for agriculture. For some, water use is also an environmental concern. The measurement and efficient use of water in these operations is important to managing costs and environmental impact.

Investors across any number of industries are also increasingly asking corporations to manage and report on their exposure to resource risks, including water, fossil fuels, and other key raw materials. Many publicly traded companies are including sustainability reporting in their annual reports. The interest of investors highlights that sustainability appeals to a variety of corporate stakeholders, including employees. Increasingly, younger generations want to work for a company that operates as a good corporate citizen, pursuing ideals beyond just maximizing profit. Sustainability can help employers attract and retain employees, helping manage critical human resources, an important component of an effective operation.

Finally, population growth and economic development are leading to a water-energy-food nexus. Each facet is critically important to society; each is facing increasing demands over the next several decades; and each competes with the other for use of finite global resources. Resource scarcity makes it important to long-term business success to use only the necessary amounts of limited resources, like water, petroleum, and other raw materials. The widespread understanding of this fact makes practicing sustainability in commercial and industrial processes a powerful opportunity to not only benefit the bottom line, but future generations as well.

About the Author
Gregory M. Gomez is the VP of flow instrumentation for Badger Meter. He joined Badger Meter in 1984 as an intern with the Inroads program while a student at Marquette University. He held several engineering positions at Badger Meter from 1987 to 2009. In 2009, Gomez became VP of business development, where he was responsible for the execution of five acquisitions between 2010 and 2014. Gomez is or has been a member of the following boards: Discover World, Wisconsin Manufacturer’s Extension Partnership, Inroads: Milwaukee Advisory Board, Great Lake Regional Board, and National Board.

Connect with Gregory:
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A version of this article originally was published at InTech magazine.

Book Excerpt + Author Q&A: The Tao of Measurement

Book Excerpt + Author Q&A: The Tao of Measurement

This ISA author Q&A was edited by Joel Don, ISA’s community manager. The Tao of Measurement: A Philosophical View of Flow and Sensors, co-authored by Jesse Yoder, Ph.D., and Richard E. Morley, was recently published by ISA. In this Q&A blog feature, Dr. Yoder provides important insights on the book’s value and significance. Bonus! Click this link to download a free chapter from The Tao of Measurement and learn new solutions that can significantly improve the measurement of time, length and area.

Q. Why do you believe the book is a “must-read” for all those involved in instrumentation or process control?

A. This book provides indispensable information for anyone involved in instrumentation or process control. It explains the principles of operation pertaining to all the main types of temperature sensors, pressure sensors and transmitters, and flowmeters. It includes a discussion of the relative advantages and disadvantages of different types of temperature sensors and their applications, and covers the main types of pressure sensors and how they work.

It explains the theory behind differential pressure (DP) measurement, and describes the operating principles behind the various types of primary elements used with DP transmitters to measure flow. These include orifice plates, Venturi tubes, flow nozzles, and other types.

The-Tao-of-Measurement-07-03

Many people involved in flow and other instrumentation topics are familiar with the types of products they specialize in, but are less familiar with the operating principles and applications of other types of instrumentation they encounter every day. This is the only book I am aware of that presents a non-technical and understandable explanation of all the main product types related to temperature, pressure, and flow. In three easy-to-read chapters, the book provides practical knowledge that enables anyone involved in these product types to become familiar with the essential information on all these products in one source.

Blog Author Q&A Bonus! Click this link to download a free chapter from The Tao of Measurement and learn new solutions that can significantly improve the measurement of time, length and area.

Q. Could you provide summaries of the book’s chapters and what makes them so valuable to read?

A. Well, first I would like to start with the chapters on time, length, and area. They all have a similar structure:

  1. A review of the history of the development of the units of measurement used to describe the relevant subject
  2. A discussion of how these terms are used today
  3. A proposal for completely new units of measurement that avoid some of the difficulties with past and present methods of measurement.

These three chapters describe how the units of measurement that everyone is familiar with and that we use today have developed over time. Some of these terms are rooted in concepts older than Roman chariot wheels. The proposals for new units of measurement attempt to bring our terminology up to date and take advantage of the technology that has been developed over the past 50 years. Each chapter has a handy glossary that defines the key terms related to the subject of the chapter.

The chapter on time explains the development of different types of calendars, and how we arrived at the calendar we use today. It explains how clocks evolved, from sundials and water clocks on through mechanical clocks and today’s digital clocks. The concept of flowtime presented in this chapter is an attempt to take our units of time out of the Babylonian era and into the era of decimal thinking that prevails in much of our methods of measurement today.

The chapter on length reviews the development of our commonly used terms for feet, yards, and meters. It examines paradoxes that are present in our concepts of “point” and “line.” Many of these paradoxes become apparent by examining Zeno’s Paradox. It describes why the concept of infinity is needed, given the assumptions present in our geometry. Wide Line Geometry is presented as a way to avoid some of these paradoxes. It presents the idea that lines have width and points have area. These new ways of looking at old concepts avoid the paradoxes uncovered and point the way towards a more coherent understanding of our fundamental geometric concepts.

The chapter on area describes some of the difficulties inherent in Euclidean geometry, which was developed around 300 B.C. Chief among these is the Euclidean method of defining circular area in terms of square inches. Just as a square peg will not fit into a round hole, Euclid’s method requires the introduction of pi (π) to make the equation for circular area work out. This chapter proposes a new geometry based on the round inch, which is a proposed new unit of measurement for circular area.   It also looks at other non-Euclidean geometries.

The chapter on flow is a comprehensive look at the different types of flowmeters, including Coriolis, ultrasonic, turbine, and many others. Besides the operating principles, the book describes the applications of each type. It includes an informative paradigm case application for each type and describes the paradigm case method of selecting flowmeters.

The chapter eight on the world of sensors and measurement defines sensors and measuring devices. It presents a theory of measuring and concludes with a listing of different types of meters.

Q. What new content or new information does it bring compared to other books on the subject?

A. Unlike other books on the subject, this book presents an easy-to-understand and intuitive explanation of temperature, pressure, and flow technology. Besides including a history of our units of measurement, it presents previously unpublished alternative approaches to these units that avoid paradoxes in our existing terminology and bring our units of measurement in line with 21st century advances and thinking.

Q. Why do you feel it provides a “fresh” look or approach to these subjects?

A. This is a fresh approach because it consolidates intuitive explanations of many types of sensing and measuring technology into a single volume. It also proposes new ways of thinking that, if adopted, would improve our units of measurement and free them from the influence of ancient and out-of-date concepts. These approaches have not been proposed elsewhere and they are proposed for the first time in this revolutionary book.

Q. Are there any specific topic areas of the book that you would specifically like to draw attention to?

A. I would specifically call attention to the chapters on flow and time. The chapter on flow is an authoritative look at all the flow technologies, along with the paradigm case method of flowmeter selection that I first proposed. It also presents the distinction between new-technology and traditional-technology flowmeters, which I first presented to the industry in 2001, and which has become standard terminology within the flowmeter industry.

The chapter on time deserves special attention because it presents a fascinating and illuminating look at the history of time measurement. It looks at the historical development of different calendars, and explains how today’s clocks and 60-minute hours have evolved from concepts older than 2,000 years. It proposes the concept of flowtime as a way to divide time into smaller units and bring our time-keeping units into harmony with the decimal thinking that is pervasive elsewhere in the world, especially in the metric system.

Q. Do you have any other comments or perspectives to add?

A. In all, this book combines intuitive explanations of technology with fascinating discussions of our most familiar ideas. It challenges many long-held assumptions, but proposes new solutions that, if adopted, would revolutionize our ways of measuring time, length, and area. The book does more than point out paradoxes in our ordinary way of thinking; it proposes new solutions to avoid those paradoxes. All this is done in a clarity of style that can only come from someone (me) who has spent 45 years writing philosophy, including 28 years writing about instrumentation and flow.

Click this link to download a free chapter from The Tao of Measurement.

Meet The Authors

Jesse-YoderJesse Yoder, Ph.D., is president of Flow Research, Inc. in Wakefield, Mass., a company he founded in 1998. He has 28 years of experience as an analyst and writer in process control. He has authored more than 180 market research studies in industrial automation and process control and has written more than 230 published journal articles on instrumentation topics. He has published in Flow Control, Processing, Pipeline & Gas Journal, InTech magazine, Control, and other instrumentation publications.

Study topics include coriolis, magnetic, ultrasonic, vortex, thermal, differential pressure, positive displacement, and turbine flowmeters. He has authored two separate six-volume series of studies on gas flow and oil flow, and is a regular speaker at flowmeter conferences, both in the U.S. and abroad.

Dr. Yoder studied philosophy at the University of Maryland, The Rockefeller University, and the University of Massachusetts Amherst, where he received a doctorate degree in 1984. He served as an adjunct professor of philosophy for ten years at the University of Massachusetts Lowell and Lafayette College. In 1989 he co-founded the InterChange Technical Writing Conference, which he directed for six years.

He is a recognized authority and expert in the area of flow measurement and market research. As an entrepreneur, author, consultant and inventor, he has helped define the concepts used in flow measurement, and is widely respected as an innovator in this field.

Dick-MorleyRichard E. Morley, best known as the father of the programmable logic controller (PLC), is a leading visionary in the field of advanced technological developments and entrepreneur who has founded high technology companies over more than three decades.

Among his many accomplishments include the attainment of more than 20 U.S. and foreign patents on products such as the parallel interface machine, hand-held terminal and magnetic thin film. His education in physics at the Massachusetts Institute of Technology formed the basis for his interest and expertise in computer design, artificial intelligence, automation and futurism.

As an inventor, author, consultant and engineer, Morley has provided the research and development community with many innovations. His peers have acknowledged his contributions with numerous awards, honors and citations. Morley has been honored by several leading organization, such as Inc. magazine, the Franklin Institute, the Society of Manufacturing Engineers and the Engineering Society of Detroit. He also has been inducted into the Manufacturing Hall of Fame.

How to Achieve Greater Manufacturing Efficiency With Online Process Metrics

How to Achieve Greater Manufacturing Efficiency With Online Process Metrics

The following tip is from the ISA book by Greg McMillan and Hunter Vegas titled 101 Tips for a Successful Automation Career, inspired by the ISA Mentor Program. This is Tip #61.

101 Tips for a Successful Automation CareerI never have quite understood why every raw material, utility, vent, reactant, recycle, and reagent flow rate and total is not ratioed to the product flow rate and total for each unit operation. The operator screens should display flow ratios (e.g., kg/kg or lb/lb), cost ratios (e.g., Euros/kg or $/lb), production rate ratios (e.g., kg/hr or lb/hr), and profit ratios (e.g., Euros/hr or $/hr). I have heard that major ethanol and pet food manufacturers do this, and have seen an increase in competitiveness between plants and shifts. I have seen energy ratios for boilers and kilns (e.g., kJ/kg or BTU/lb) but not much in terms of ratios for chemical and pharmaceutical plants. Knowing how process performance changes with changes in operators, maintenance, and process technical support may be disconcerting at first but ultimately productive, possibly spurring competition between operators, engineers, technicians, and plants to do better. Here the old adage applies, “You cannot control something you don’t measure.” In order to improve the performance of each unit operation, you need to measure the performance of each unit operation. As with anything measured, automatic control is better than manual control. A linear program (LP) in model predictive control (MPC) can do automatic optimization of the metrics by the use of cost ratios and profit to find the optimum intersection of operating conditions.

Nearly every process input that is set by operators or automatically manipulated by controllers is a flow. There should be a measurement of every flow for process analysis besides metrics. We are accustomed to flow measurements of raw material, reactant, and product streams, but wireless transmitters and insertion-type flowmeters (e.g., annubars) make flow measurement affordable for the remaining streams.

If we have all the flows, we can do a material balance and implement plantwide feedforward control (Tip #101). We can correct for pressure disturbances and valve nonlinearities by flow control, making the job of PID control (and particularly model predictive control) much easier. Because process gain is a nonlinear function of the ratio of manipulated flow to total flow, the process time constant is proportional to residence time, and transportation delay is inversely proportional to flow rate, we can intelligently schedule tuning settings.

We can add wireless temperature measurements and do energy balance, heat release, and heat transfer calculations. We can develop inferential measurements of concentrations using neural networks, projections to latent structures, and first principles. We can improve the fidelity of a virtual plant. Since we have flow control, we do not need to have a pressure flow-solver in the virtual plant to know the flow through valves, and can adapt model parameters based on flow ratios (Tip #98 and Tip #99).

Concept: Operating efficiency can be computed from a ratio of flows and assigning dollars per unit flow. Online metrics open the door to process understanding and innovations by the quantification of benefits and first principle relationships.

Details: For continuous processes, compute the increase in production flow or onstream time or the reduction in the ratio of a utility, raw material, recycle, or reagent flow to a production flow. You should compute the ratios on a filtered instantaneous basis and as a ratio of totals for a representative period such as a shift. For batch processes, compute the ratios as flow totals to product total per batch and estimate the batch cycle time to get a production rate. For batch processes, efficiency is increased by higher batch end point concentration or lower total utility use and raw material feed per batch. Batch process capacity is increased by a shorter cycle time. Use ballpark estimates of dollars per unit mass (e.g., lb or kg) and normal production rates to get to the bottom line ($/hr or $/batch). Coriolis meters provide the ultimate in terms of accuracy of flow and density measurements and two-component composition measurements (Tip #73). Total heat release measurements can provide an inferential measurement of reaction conversion and the heat release rate can provide an indication of conversion rate and batch completion.

Watch-outs: Signal filters may be needed to reduce the noise in flow and cost ratios. To synchronize an upstream flow or utility flow with a downstream product flow, flows may have to be passed through a deadtime block and filter block to simulate transportation delays and residence time lags. There may be an inverse response and a temporary decrease in efficiency from the action of an LP and MPC that can cause impatient operations personnel to think the advanced process control (APC) system is doing the wrong thing. For example, if a reactant feed is increased to be closer to the optimum stoichiometric ratio, the yield would decrease if the change in reactant flow is not delayed and lagged to match the change in measured product concentration and flow out of the reactor.

Exceptions: The synchronization of raw material flows with final product flows after many batch and continuous processes may not be possible, causing metrics to be erratic. Synchronization is particularly difficult when there are several unit operations between a flow being manipulated and a product flow being measured for optimization.

Insight: Process metrics depend upon flow measurements.

Rule of thumb: Add flow measurements to every important stream and compute online metrics for the process efficiency and capacity of each key unit operation.

Improving Distillation Tower Operation

This is an excerpt from the January/February 2013 InTech Web Exclusive feature by Daniel P. Lucey. For the entire article, please see the link at the bottom of this post.

Fuel Production

The distillation process uses enormous amounts of energy, consuming up to 50 percent of a refinery’s operating costs due to intense heating and cooling cycles. Proper distillation tower operation can reduce energy consumption, but plant personnel need the right information in order to improve operation.

Specifically, operators must have precise measurement and control of numerous variables, including feed and vapor flow rates, tray levels, process pressures, and temperatures. In practice, measurement of all these variables, except for temperature, is often made with pressure transmitters.

Problems can occur when operators and engineers have insufficient information about operating conditions. Failing to properly monitor and control process variables can result in decreased product quality and throughput, increased energy costs, and unsafe operations that put employees and capital equipment at risk.

Using a purpose-built electronic remote sensor system is one way to calculate differential pressure (DP) and to provide additional process information that can be used by plant personnel to increase efficiency, save energy, and boost throughput. Such a system can also cut required maintenance and increase uptime.

DP measurements indicate tower health

Figure 1. Conditions at the bottom of the distillation tower are different from those at the top of the tower, so the more DP measurements made, the better the operator’s process insight.

Figure 1. Conditions at the bottom of the distillation tower are different from those at the top of the tower, so the more DP measurements made, the better the operator’s process insight.

Vapor flow rates and feedstock levels are calculated by measuring tower pressures. Flow, pressure, and temperature measurements allow the operator to detect process upsets, such as foaming, entrainment, weeping, and flooding.

A sudden decrease in tower pressure can cause tower feedstock to boil, which in turn drastically increases the vapor flow rate. Entrainment or flooding occurs when vapor flow rates are too high. A rapid increase in pressure can cause immediate vapor condensation, resulting in tray dumping, and ultimately requiring a total tower restart.

DP measurements provide information needed to better control the distillation process. When a distillation column is in an ideal state and operating consistently, the DP within the tower will remain stable. Strategically raising or lowering the pressure will improve product separation and quality. Energy savings can be dramatic, saving up to one-third as compared to operation at a fixed pressure, as heating and cooling cycles can be controlled more efficiently.

At a minimum, a single DP measurement should be made across the entire tower. An even better solution is to additionally measure the DP across the stripping and rectifying sections, as well as individual trays. (Figure 1) Pressure measurements can be implemented as needed across trays to further improve the operator’s process insight.

To read Daniel P. Lucey’s full article, click here.

Daniel P. LuceyAbout the Author

Daniel P. Lucey is a marketing engineer for Emerson Process Management’s Rosemount Measurement Division. Dan joined Emerson in 2011, and his primary focus is on the 3051S Electronic Remote Sensors (ERS) System. He received a B.S. in Mechanical Engineering from the University of Saint Thomas. Contact: Daniel.Lucey@Emerson.com

Are changes in pipeline pressure affecting your loop?

This guest post is authored by Greg McMillan.

In the ISA Automation Week Mentor Program, I am providing guidance for extremely talented individuals from Argentina, Brazil, Malaysia, Mexico, Saudi Arabia, and the USA. We will be sharing a question and the answers each week. If you would like to provide additional answers, please send them to Susan Colwell at ISA. The tenth question in the ISA Mentor program is from Danaca Jordan (USA):

“How can you tell if changing pressure in a pipeline is affecting your process control loop?”

While it is well known changes in pressure change the control valve flow, less recognized is the changes in the installed characteristic and the prevalence of pressure upsets. Liquid flow (unless there is flashing) through a control valve is proportional to the square root of the pressure drop across the valve. The installed characteristic changes as the ratio of the valve to total system drop changes. You can track down disturbances by finding what flow changed first (see “Tracking Down Disturbances”). If you don’t have a flow measurement for each control valve, it gets difficult. If there are multiple users of the stream, then a pressure change in the stream will cause coincident changes in the controller outputs of the users. If there is only one user of the stream with the pressure change, the first process controller output that starts to change was first affected by the stream pressure change either as a disturbance flow or manipulated flow. Different loop deadtimes can mess up this analysis depending upon disturbance type and path. Data analytics packages can determine correlations between process variables and flows but multivariate statistical process control assumes linear relationships and synchronization of inputs with outputs for continuous processes. Unmeasured disturbances, inputs that are valve positions (nonlinear installed characteristics) rather than flows, and process deadtime are problematic for applications in continuous operations. If you had wireless pressure transmitters, you could move them around to track down the source pressure changes. If you had secondary flow loops (see “Secondary Flow Loops Offer a Primary Advantage”, the question would go away because the flow loop would correct for the pressure change before it affected the primary process loop. Changes in stream temperature, composition, and density are also disturbances. If you don’t have measurements of these stream variables, you are relegated to identifying the first flow to be affected. Often a process controller changes a manipulated flow to counteract the stream changes. For ratioed flows (flow feedforward), the primary process controller adds a feedback correction for stream changes. Secondary flow loops are essential for flow feedforward.

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