Emerson Process Experts

I received an email from a university student with a great question the other day. It prompted a great answer from Pete Sharpe, a Principal Advanced Automation Consultant. You may recall Pete from earlier posts on process optimization.

I've retained the anonymity of the person asking the question by editing the question:

I am doing my thesis on estimation of benefits by implementation of advanced control, I read your articles in this field and it help me so much, but I still have some questions, I would like to know if you could give me information about how to calculate the benefits to pour point, viscosity and Research Octane Number (RON). I will be grateful for your help.

Pete responded:

I was forwarded your request about calculating benefits. I've had some experience in this area. Are you estimating benefits for a blending process? If so, the opportunity is to reduce variability and approach the specifications closer using less of the more valuable components. So instead of making 87.5 RON on the average, you reduce it to 87.1. The value is the total blend rate times the difference in average octane times the octane barrel cost.

Anyhow, I'm attaching a paper that perhaps might help describe how these benefits are calculated.

I contacted the ISA and received permission to re-host this paper, Estimating Benefits from Advanced Control (Copyright © 1986 ISA. Reprinted by permission. All rights reserved.)

In the paper, the authors (Pete, P.L. Latour, and M.C. Delaney) apply statistical methods to estimate savings from dynamic control improvement and steady state optimization. At the end of the article, they run through a distillation column example calculating annual dollar savings by reducing process variability and thus allowing the column to operate more closely at its limits.

Whether you're a student or a project engineer, you might find the calculations in this "oldie but goodie" paper useful in trying to estimate and quantify the benefits for your project.

Tags: research octane number | benefits estimation | process optimization | advanced control | advanced process control | APC | steady state optimization | distillation column |

May 9, 2008 in Distillation Column, in Process Optimization, in Refining | Comments (0)

Emerson's Jonas Berge is an active member in the ISA SP104 committee, responsible for advancing the Electronic Device Description Language (EDDL) standard (also known as IEC 61804-3.) You may recall Jonas from earlier EDDL posts. This standard creates interoperability between digital field devices from simple sensors to complex devices (drives, analyzers, etc.) with control and asset management systems. Interoperable communications include device diagnostics, asset management and user interface displays.

Jonas has written a short piece, OPC Made Easy, in the April issue of Control Engineering Asia magazine. In this article, he describes how EDDL can save many hours of OPC server configuration, which can help speed up a project's completion. For background, he begins by reminding readers how this important standard makes sharing data between OPC servers and OPC clients easy:

…external software in HMI clients and other users can easily access the wealth of detailed diagnostics and information in hundreds or thousands of intelligent devices around the plant.

Configuring OPC clients is easy: just point and click on data in the OPC server.

The challenge is in the configuration of the OPC server:

Configuring the OPC server includes entering device addresses and communication settings as well as creating the "namespace" which entails entering tag or descriptor for each and every piece of information along with the memory register address for the parameter as well as its data type, and range where applicable. This parameter "mapping" is the most time consuming and error prone part of OPC integration, but once done the rest is easy.

Jonas explains how EDDL can automate the creation of the OPC server configuration for devices digitally communicating via HART, Foundation fieldbus and Profibus. He writes:

Automatic OPC server configuration is made possible because EDDL is a descriptive technology similar to XML or HTML, declaring the properties of the data in the device for use by the auto-configuration mechanism. EDDL is the only device integration solution that is declarative.

Although not in the article, Jonas relayed an example to me where an AMS OPC Server was used to pass a slug flow alert from a Micro Motion HART device to an older distributed control system (DCS) that did not support HART communications pass-through. Before the solution was implemented to send this alert to the DCS via OPC, slug flow would cause over-charging of materials added to a batch. Now, the operators are alerted to slug flow conditions and can pay special attention to the surrounding process equipment.

The EDDL.org website remains the best source for information about this standard. You can also join the EDDL email list hosted by ISA to keep up and participate in the conversation around this standard.

Tags: EDDL | electronic device description language | SP104 | IEC 61804 | OPC | OLE for Process Control | HART communications | Foundation fieldbus | Profibus |

May 6, 2008 in Alarm Management, in Interoperability, in Measurement | Comments (0)

I mentioned submittal of two social media-based abstracts to the Emerson Exchange in an earlier post. Each year, the Emerson Exchange board members receive way more submittals than they can accept, so anyone who wants to present has to keep their fingers crossed.

The good news is that one of the two was accepted. Deb Franke and I will be presenting:

Feeding that Inner Geek

Join Deb Franke and Jim Cahill in a conversation on using the internet, high-tech gadgets, and social media technologies that will enable you to be more productive and effective in all that you do, especially in your working career.

We picked this title because it was the title one of the most visited blog posts on this site to date. And with the Emerson Exchange's hundreds of sessions to choose from, we wanted a title that might stand out.

The goal is to build on presentation we did last year, Getting the Most Value from the Internet: How New Web 2.0 Tools and Techniques Can Help You Innovate.

Social media tools continue to proliferate as people learn the value they can bring. Two examples that we did not discuss last year are Twitter and Friendfeed. Friendfeed is new and Twitter is rapidly growing. I have been looking into the utility of Twitter for people with interest in the DeltaV system, to connect and communicate directly with one another. As learning occurs along the way, I'm sharing tips with our nascent DeltaV Twitter community.

The common thread with these social media applications is that they connect people with other people who have similar interests. Our hope is that one of these interests is around our world of process automation.

One final note, we have the honor of being one of the blogs mentioned in the new book, Groundswell. Written by Forrester Research principal analysts, Josh Bernoff and Charlene Li, it helps you and your business clearly formulate your strategy with respect to social media. I just finished the book the other night, and in the spirit of the groundswell, put my review of it on Amazon.com. Hint… I liked it.

Tags: emerson exchange | web 2.0 | social media | groundswell |

May 2, 2008 in Education, in Emerson Exchange | Comments (2)

Courtesy of Emerson's VP of wireless technology, Bob Karschnia, I received a draft copy of a whitepaper circulating about redundancy in WirelessHART device networks. It's not yet finished so I don't have a link, but here are some of the key thoughts I gleaned from it.

Redundancy, in this context, is defined as a duplication of critical system components to reduce the probability of a failure caused by a single component. This redundancy is available at three levels including the network of wireless field devices, the access points and the gateways to the control and/or asset management systems.

Starting with the wireless field devices, the WirelessHART standard supports communications redundancy through multiple paths (spatial diversity), multiple transmission frequencies (frequency diversity) and multiple timing possibilities (time diversity).

Consider a wireless temperature transmitter mounted in your process communicating with other wireless devices—say a pressure and level transmitter. This device creates a self-organized communications path through one of the other devices back to an access point or directly to a wireless gateway. If the path through this device is obstructed, the temperature transmitter will retry at a slightly different time, frequency and path to the other device. If it fails, it will retry—again adjusting time, frequency, and path.

As we discussed in an earlier post, Planning Your Wireless Instrument Installation, it's important that each wireless device have at least two other devices to communicate with to provide alternative paths when needed.

An access point is a specialized WirelessHART device with a high-bandwidth communication interface to the gateway. Multiple access points can be connected to the gateway to provide path diversity and increased bandwidth across the network. There is no limit to the number of access points in the field network.

At the highest level of the field network is the gateway, network manager software and security manager software. The network manager performs scheduling and routing services. The security manager performs security key generation and storage as well as field device authentication services. All three components can reside within a physical gateway or can be distributed in separate gateways.

Using a mechanism similar to redundant controller pairs available in most automation systems, primary/backup redundancy management is being developed and stress-tested for these gateways.

I'll keep a sharp eye out for the finished whitepaper and update this post with a link.

Tags: WirelessHART | sensor network | field network | wireless transmitters | wireless device network | communications redundancy |

May 1, 2008 in Interoperability, in Technologies, in Wireless | Comments (0)

I received an email with a great question to an earlier post, Improving Local Control around Safety Shutdown Valves. The question was:

Can you provide more information on your Local Control panel with Safety Shutdown Valve that haves a quick exhaust systems; can the partial stoke test not close the valve do to differential pressure on the quick exhaust system. Also if a shutdown signal is given during a test will it close the valve?

I spoke to Riyaz Ali, who shared his expertise in the earlier post. Here's his great answer in its entirety with picture and hyperlink added by me:

It is true that use of quick exhaust valve (QEV) on large valve with DVC6000 SIS for partial stroke test may dump large air during test. Generally, QEV operates on water column pressure differential and are sensitive. However, we recommend using volume booster on those applications where stroking speed is concern. One may argue that Volume Booster is for "Fill" time and not for "Exhaust". However, we have done test in the lab and established that volume booster will be much better pneumatic accessories, specifically when used with DVC6000 SIS for partial stroke test without causing instability in the operation during partial stroke test and as well meeting stroking speed requirements.

The picture illustrates a schematic of a large spring-return piston actuator with a DVC6000 and a volume booster to achieve a stroking speed requirement of less than two seconds.

During PST test, if demand arises DVC6000 SIS will take valve to safe state.

Here is more information about the LCP100 (Local Control Panel) for your perusal.

I hope that pulling this process safety-related question out of the realm of email into the open might help someone else with similar questions.

Update: I'd like to thank commenter JM for pointing out my LCP100 hyperlink going to the wrong spot. I've fixed. Thanks, JM!

Tags: safety instrumented system | SIS | process safety | safety shutdown | quick exhaust valve | QEV | piston actuator | volume booster |

April 29, 2008 in Final Control Element | Comments (1)

The ControlGlobal.com site has a great article on process safety, Leading the Way to Process Safety. Author Peter Montagna describes the importance of leadership:

With strong leadership, a process safety program can achieve many goals. It can satisfy shareholders and company management with improved productivity and profitability; satisfy the community with fewer incidents; and satisfy employees with a healthy and safe working environment.

I ran this by Emerson's Chuck Miller whom you may recall from earlier posts on process safety. He's been preaching the critical importance of competency in functional safety management.

When I forwarded the RSS feed of the ControlGlobal.com story his way and asked his thoughts, Chuck as usual had some good ones. He wholeheartedly agrees that leadership is an important component:

…safety culture and competency … that is culture creation has to be a driven from the top down. The leadership must set the standards and evaluate the process of the program. Management relates to the implementation of the process.

Chuck adds that there is a distinction between management and leadership. He writes:

However, many do not separate management and leadership, but instead combine the two. I place this as the leading metric of success or failure of the process. Changing culture in a work environment requires that you have the right people in place. They are hard to find but they are out there. To be effective it takes someone from the outside (of the work group) with the right credentials to drive the mission—no relationships or baggage to complicate the change agent with compromises.

Peter expressed a point in the article, "Then the process safety specialist leader has to form a team and help it create a compelling vision…" Chuck took a different view. He writes:

I put this responsibility on leadership (visa vie our Functional Safety Management Board) whose visionary commitment sets the goal and strategies to get there. For me it takes leadership PLUS a commitment from all levels of the organization—these implementers are the safety specialists and they drive the commitment.

For your process safety efforts, what are your experiences?

Tags: functional safety | process safety | safety leadership | safety competency |

April 25, 2008 in Safety | Comments (0)

There's a great article on The Institution of Engineering and Technology's website, Industry Unplugged, by Emerson's Mike Ferris. Mike is with the Smart Wireless team in the Rosemount Measurement business of Emerson Process Management.

Mike's conclusion describes why process manufacturers might consider wireless field networks (a.k.a. wireless sensor networks.) He writes:

Wireless offers the ability to add additional measurement points to previously unreachable or unaffordable places throughout the process plant. This means greater access to information about the process and also the health of devices. Wireless mesh networking solves the problem of reliability within tough non wireless-friendly areas. Security issues have been addressed and in WirelessHART the process industry has an open standard to work with. By adding plant wide wireless networks it is now possible to improve the availability of this extra data to those that need it most.

Mike notes the adoption of wireless networks in our homes and offices and how it has become a part of our daily lives. This has not been the case in process manufacturing plant applications. A number of reasons he cites include a limited range of sensors and transmitters for acquiring data, security concerns, power concerns, and a lack of industry standards. Most wireless solutions were point-to-point, which prevented the ability to scale if the application required it.

These concerns led to the WirelessHART standard that I discussed in an earlier post. The architecture scales, installs in a straightforward way, and has well thought through security. For more on the underlying IEEE standards and protocols, this data sheet provides a good summary.

The main objective of WirelessHART is to be fully complementary to the wired HART standard. As such, it extends standard functionality like electronic device description language (EDDL) and provides process manufacturers a similar user experience whether the HART device connects wirelessly or via wires.

In the article, Mike offers application examples as opportunities where process manufacturers might give wireless field networks a try. I'll summarize his ideas in a bulleted list:

• Applications not justifiable when wiring installation costs included
• Remote devices in hard-to-reach areas
• Uninstrumented operational blind spots
• Existing HART devices with no way to deliver diagnostic information
• Manual readings done in hazardous locations
• Automating operator rounds
• Incremental measurement points
• Measurements on rotating or moving plant equipment (ex. lime kilns, rail cars, portable skids, etc.)
• Safety relief valve emissions monitoring
• Safety shower flow

Of course, many of these examples are possible. It's more the case that they are not practical once you factor in the wiring installation. It's kind of like your home. Some things are more trouble than their worth to do when wiring is involved. With a wireless option, things get a whole lot simpler and more doable.

Tags: WirelessHART | wireless field network | wireless sensor network | operator rounds | safety relief valve | safety shower |

April 23, 2008 in Wireless | Comments (2)

ModelingAndControl.com's Greg McMillan and Solutia's Mark Sowell will be presenting at the upcoming ISA 54th International Instrumentation Symposium. Their paper, Advances in pH Modeling and Control, describes the use of embedded simulation, coined "Virtual Plant" and model predictive control to improve the control of pH levels in a plant waste water treatment application.

The authors begin by describing the challenge of pH control:

The pH electrode offers by far the greatest sensitivity and rangeability of any industrial process measurement in terms of the measurement of concentration (hydrogen ions). To realize the full potential of this opportunity requires extraordinary performance of mixing equipment, control valves, reagent delivery systems, flow meters, control system design, and controller tuning.

The virtual plant is described:

A virtual plant can be used to sort out fact from fiction important for insuring performance and reducing capital and operating costs. The virtual plant consists of a download of the actual control system configurations and displays, embedded advanced control tools, and a dynamic process model running on personal computer...

The articles details the control strategy used:

We developed and prototyped model predictive controllers (MPC) to replace the fuzzy logic control system. MPC-1 adjusted the 1st stage pH set point to keep the second stage reagent valve at a minimum position for good response and reliability. MPC-2 trimmed the 2nd stage set point to keep the pH in the tank at an optimum pH.

The authors describe the interaction of the virtual plant with the real plant. They write:

In order to study and improve performance of the control system and the fidelity of the process model for actual process conditions, we put the virtual plant in a read-only mode online running real time. A simple interface module was configured that used object link[ing and] embedding for process control (OPC) to read indicated waste flows, controller set points, and controller modes from the actual plant.

If you are battling pH control in a waste water treatment application, you'll want to give this paper a read. You might also want to get your hands on one of Greg's books, Advanced pH Measurement and Control, if pH control is currently vexing you.

Update: Greg wrote me that the presentation went well and the room could have been bigger to hold all the folks interested in hearing about this topic. He has done a slight revision on page 1 to better tie in the results to the general situation with pH systems. This version is now posted on the original hyperlink above.

Tags: pH modeling | pH control | virtual plant | process simulation | waste water treatment |

April 21, 2008 in Control Strategies, in Process Optimization, in Regulatory Compliance, in pH Control | Comments (0)

My spy utility, WatchThatPage, alerted me to another good article, this time on the Fisher control valves and regulators area of the Emerson website. The article, Getting ready for the nuclear renaissance, from the April issue of Valve World magazine, features Bill Fitzgerald, director of the Fisher Valves nuclear business unit.

As more and more people around the world climb the economic ladder, the global demand for energy continues to grow. A nuclear power renaissance is underway, according to Bill driven by:

…issues like global warming and a desire for energy independence... It can never be the only solution, but it is a logical part of the solution.

Bill describes his team tracking forty U.S. projects. He estimates two-thirds of these will actually be built. The first ones may come on-line as soon as 2015. Bill describes the large engineering firms as well as the U.S. Nuclear Regulatory Commission (NRC) staffing up anticipating the work required to completely design, build and commission the first wave of these plants over the next seven years. This expected growth is by no means limited to the U.S.

As part of this process, the engineering firms' procurement people need to identify and begin to purchase the long-lead items like reactor vessels, which may take three years from order to delivery. Control valves also fall into this long-lead item category. As Bill explains:

…control valves have long lead times because the ASME has just issued new qualification requirements. So to use a valve in a given safety related application will probably require 18 months of qualification testing. We also have to factor in ever-tighter seismic requirements. Then materials procurement, machining, assembly and testing will probably take an additional 9-18 months, depending on valve type. So, we believe that if we get an order today for a nuclear grade valve it could take as long as three years to actually deliver it to the end user.

And Bill notes that these valves are used in safety critical areas. Not having them will delay the startup of the plant. Based upon this expected global increase in nuclear power plants, Emerson and other automation suppliers are increasing their capabilities to meet this demand.

Technology has changed greatly since these types of plants were built in the U.S. a generation ago. Bill describes digital technologies like Foundation fieldbus, which can be used in the balance of plant applications to provide better control and diagnostic information. Devices like digital valve controllers have completed Electric Power Research Institute (EPRI)-certification for use in this demanding application.

As energy producers seek ways to meet the increasing global energy demand, these preparatory activities are critical to meet challenging project schedules.

Update: I was just pointed to a great Béla Lipták article, The Third Industrial Revolution by a member of our DeltaV Twitter community. Béla describes the post fossil fuel world based on solar power and the role of process automation. It's well worth your read and I look forward to his book due out in August.

Tags: nuclear power | control valve | safety valve | digital valve controller | valve regulator | Foundation fieldbus | NRC | ASME | EPRI |

April 16, 2008 in Foundation Fieldbus, in Plant Equipment, in Power, in Regulatory Compliance, in Safety | Comments (0)

I read Dick Caro's, Which Way Wireless article published last Friday on the ControlGlobal.com site. It discusses WirelessHART and ISA100.11a and their paths to standards. He describes ISA100:

ISA100.11a is the name of the first standard being developed by the ISA SP-100 standards committee. The committee was officially chartered in 2005, with an editing team created in early 2007 to actually write the standard. Completion of the standard's first draft is scheduled for November 2008, and it may be that this schedule will be met.

Let's check this schedule against past standards to get a reading of when products might be expected.

The only standards effort in which I was fortunate to participate was the original launch of the OPC standard—then called "OLE for Process Control." A task force with Microsoft in a consulting role and five automation suppliers: Emerson (then Fisher-Rosemount), Intellution, Rockwell Software, Opto 22, and Intuitive Technologies announced the initiative at the ISA show in October 1995. The objective was to create a real-time communications standard based on Microsoft's OLE and COM technologies. Emerson served as master editor for this initiative.

The first draft of the specification was released in December 1995 and a second draft in March 1996. Three global seminars were held to teach interested parties about the standard's scope from April through August of 1996. Version 1.0 of the specification was release at the end of August 1996.

A beta release of the initial DeltaV system came out late in the fall of 1996, and the general release occurred in the spring of 1997. It was one of the first, if not the first, OPC server and OPC client commercially available. From the announcement of the task force in the fall of 1995 to commercially available products in the spring of 1997, this has to be one of quickest standards development efforts in process automation history. This standard, now referred to as OPC-DA, is maintained by the OPC Foundation and is still widely used today as a way to integrate software, systems, and devices.

I think this effort progressed quickly because Microsoft technologies were becoming increasingly important in process automation solutions and the existing method of communication, DDE, had its limitations that most acknowledged.

I haven't been real close to the WirelessHART path to standard, so I called Terry Krouth, Emerson Process Management's Chief Technology Officer, to understand its path to a standard. The wireless portion came with the HART 7 specifications formally approved by the HART Communication Foundation (HCF) members last June and authorized for release by the HCF board in September.

The HCF launched the WirelessHART initiative in November 2004. Its objective was to establish a wireless communication standard for process applications and enable wireless access to existing HART devices whose installation numbers more than 20 million. More than 25 companies were involved in its development including most of the major automation system suppliers. This HCF whitepaper, Why WirelessHART, shows a timeline with the major milestones on its successful path to ratification.

Terry noted that while the WirelessHART spec was being written, an extensive field-testing program was designed and conducted. Hundreds of prototypes were installed in actual field conditions to verify that the specification correct and workable. To make sure the standard would meet its objective, use cases of application scenarios were developed to make sure the standard could be used. HCF also donated these use cases to the ISA100.11a effort in June 2006.

Just last month, Emerson announced it is taking orders for the first products compliant to the WirelessHART standard. This comes a year and a half after the first wireless field network products became available in October 2006. Like the OPC standard, it takes time once the final standard is ratified until products become orderable and commercially available from the automation suppliers.

Like the immediate value OPC standard created around interoperability, the WirelessHART standard is making around "hard to get at" diagnostic information. I've chronicled some of the successful applications like wellhead pressure measurement and tank farms level measurement.

Other applications that have been spotlighted include railcar temperature measurement, temperature profiling, hot strip mill water flow, and remote pumping.

WirelessHART-based field networks open up possibilities to provide diagnostic information that is not practical or perhaps even possible to get at with conventional wiring. Process manufacturers are quickly realizing the value when they install these networks as these examples demonstrate.

Update: I'd also like to point out a webcast, The Range of Wireless, that Automation World magazine is hosting. It will be held April 17, at 2pm Eastern U.S. time.

Tags: WirelessHART | field network | SP100 | ISA100.11a | OPC | OPC-DA | HART Communications | device diagnostics |

April 14, 2008 in Interoperability, in Wireless | Comments (0)