ProNamics Control Inc.

ProNamics is very pleased to announce that we are now an authorized distributor and provider for Control Station's LOOP-PRO Products. The LOOP-PRO product suite is outstanding software for loop optimization.. For more information visit our Control Station Page.

Opportunities for Feedforward Control

The primary virtue of feedforward control is that it produces an immediate control action in response to a load disturbance. Unlike the feedback controller it does not wait until the controlled variable is disturbed to take control action. As such it has the potential to more completely attenuate the effects of a load variable. The benefits of feedforward control can be particularly high if the feedback control capability is limited by a high amount of process deadtime and process lag time.

Please click on Feedforward control to read more about implementing this strategy and to take the feedforward quiz .

Opportunities for Cascade Control

Developing optimum tuning for PID controllers requires an understanding of both the system dynamics and the process objectives. This is a straight-forward and inexpensive first step in process optimization. Optimum tuning does not mean that the controller will be effective at responding to all disturbances. An important insight is that the PID control performance is largely dictated by the process dynamics. Control loops with slow dynamics will usually require slow tuning . Attempting to speed up the PID controller beyond the inherent loop dynamics usually ends up increasing process variability. If the process dynamics are highly non-linear even more conservative tuning will be necessary – further limiting the overall performance.

For important control loops, if the process objectives cannot be achieved with a simple PID controller, a more sophisticated strategy needs to be considered. There are no shortage of model based controllers on the market and these can be very effective in process systems with slow dynamics, interacting process dynamics and a high level of non-linearity. For these advanced packages to succeed in the long term, there must be a commitment to investing in the human technical resources to develop and maintain the process models/controller performance. All too often, the model based controllers are placed into the ‘black box’ category and tend to be ‘turned off’ when unexplained process upsets occur.

It is our view that intermediate level strategies such as cascade, ratio, feed-forward and decoupling control are underutilized and can often deliver the required performance improvement . Recognizing opportunities for these strategies will be the focus of our web updates over the next several months. In this update, we are focusing on opportunities for Cascade control.

Optimizing Pumping System Performance

Pumping systems are composed of pumps, pipelines, control valves and other process equipment. A program to improve pump system performance needs to consider the entire system - not just the pump. Proposed modifications to the pumping system need to be assessed according to the impact on energy consumption. process variability, control performance and maintenance costs. Please refer to our Pump System Performance Survey information sheet for further details on ProNamics approach to this important activity.

Click on the November 08 challenge answers to view the answers to our challenge questions posted in the last update. The ProNamics ‘Stock Flow Simulator’ was used to generate the detailed results for each option under consideration. This simulator was designed to assist in pumping system optimization and considers the impact of process modifications on pumping cost, control performance and process variability. Click on the Process Simulator 2009 brochure for more information.

ProNamics Loop Monitoring System Surveys

The most popular systems are LoopScout from Honeywell, PlantTriage from ExperTune, PC Doctor from Matrikon, and ControlTrac from Capstone Technologies. While these systems have the potential to improve process performance, many fail to deliver value. This is due in large part to the misconception that only minimal human resources are required to realize the full potential of systems. The reality is that the loop monitoring system can help to improve the efficiency of existing optimization personnel. Moreover, the optimization group needs to understand concepts of process dynamics, controller performance, process non-linearities, time series analysis techniques, economic benefits analysis and troubleshooting procedures. Otherwise, the monitoring system will add little value.

ProNamics Loop Monitoring System Optimization Program can play an important role in helping the mill realize the full benefit of these systems in the following areas.

Establish realistic and achievable loop performance standards for the process loops
Improve the troubleshooting skills of E&I and process control personnel
Conduct Periodic Workshops to prioritize the Loop Monitoring system recommendations and document improvements

Please refer to our Loop Monitoring System survey information sheet for further details.

Upgrading the troubleshooting skills of the mill process control and process optimization personnel is critical to the success of these programs. ProNamics Process Optimization & Troubleshooting Techniques course will give the mill personnel the skills to better appreciate the benefits of these systems.

Please call or send us an email if you'd like to learn more about our Loop Monitoring Systems survey or our Process Optimization & Troubleshooting Techniques course.

Energy Consumption and Control Performance

ProNamics has conducted over 100 process and control surveys in the last 8 years. A common survey finding is that oversized pumps and control valves compromise the performance of the control loop and result in higher process variability. The tendency of the design engineer to oversize is understandable. Uncertainties about pipe friction losses, the accuracy of pump performance and valve Cv curves, and future production requirements all drive toward higher pump and valve capacity. Nonetheless, oversizing results in higher operating costs (more energy to run the pump), higher process variability (greater vulnerability to backlash and stiction), and higher maintenance costs (higher risk of cavitation at the pump and valve).

The ‘best solution’ to oversized pumping systems could involve valve re-sizing, trimming the pump impeller, installing a VFD, replacing the pump/motor, modifying the operating strategy or a combination approach. While a reduction in energy consumption is typically the most easily quantifiable benefit, it is often not the most important. The impact of proposed process modifications on control loop performance, process variability and maintenance costs all need to be considered in order to make the best decision

ProNamics can help, both in identifying opportunities and in recommending the best solutions. Our field tools, which include power loggers, pressure transmitters and high speed data acquisition equipment, are used to document operating conditions, identify opportunities and quantify any implemented improvements. Our dynamic simulation tools assist us in quantifying the impact of process modifications.

We will be posting a series of ‘Energy and Control Performance’ challenge questions over the next several months. These challenges are based on process systems that ProNamics has recently audited. Click on Sept08 challenge to review this months challenge . We will be posting the answers in our October/November update.

Wet End Troubleshooting
'Effective wet end troubleshooting requires not only good tools but well defined procedures and good follow through as well' C.A King TAPPI editorial board

The Lean Stock system is often the most important contributor to BW variability in the 1 to 60 sec/cycle range and an important contributor to process inefficiency. The lean stock system process dynamics are complicated and sometimes counterintuitive. Moreover, the troubleshooting task is complicated by the lack of reliable instrumentation. An analytical approach is particularly important.

Please refer to Lean Stock System survveys for more details on our approach to wet end troubleshooting.

Maximizing the Value of a Loop Monitoring System

In the past year or so we have been requested to review and assist with the evaluation of Loop Monitoring Systems and the system reports. To help us better understand the capabilities of these systems and their reporting, we conducted a brief survey of a select few systems and interviewed the users of these systems to see how they are performing. We collated our findings into a paper which we presented at the PACWest Conference in Harrison Hotsprings, BC.

Introduction:
Process variability directly impacts operating efficiency, the amount of chemical and energy consumed, and product quality. As such, variability management programs offer major opportunities. Knowing the amount of variability in key processes and its impact on production and cost should mean that the key process loops are optimized and the right equipment is fixed at the right time. The ultimate result is lower production costs and higher maintenance efficiency. An on-line tool that identifies and prioritizes control loop problems should provide an important assist in process optimization. Yet this has not been the most common outcome. After an initial period of interest, these tools too often fall into disuse. The reasons for the limited amount of success and the keys to improving the long term usefulness of these tools are the primary focus of this Maximizing the Value of a Loop Monitoring System paper.

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Please send us an email if you'd like to learn more about Loop Monitoring Systems.

Benefits of Optimization Services

Paper Machine Optimizations
ProNamics recent paper machine optimization surveys have increased machine efficiencies, improved registration and reduced cull.

Control improvements to stock blending eliminated excessive fiber flow and consistency cycling improving machine efficiencies during light weight grades.
Reductions in totalhead variability by eliminating cavitation in the lean stock piping through adjusting cleaner pressures eliminated high rush/drag variability and mis-registration.
Control valve and control performance improvements to the dearator overflow level contol reduce machine direction basis weight variability reducing cull during light weight grades.

Boiler Optimizations
ProNamics recent utility, hog and recovery boiler optimization surveys have increased boiler uptime, increased hog consumption, reduced gas usage, improved boiler efficiency and reduced steam header pressure variability.

Control improvements implemented to drum level control have reduced boiler trips due to drum high/low level trips.
Control improvements implemented on boiler master controls and constraint controller dramatically increase hog consumption and reduced gas usage while reducing steam header pressure control induced variability.
Process and control testing identified several damper and control loop health issues resulting in poor air/fuel ratio control resulting in high boiler excess air/O2 reducing the boiler efficiency.

Pipeline Pressure Control Optimization
ProNamics recent petroleum pipeline pressure control optimization services have resulted in dramatic improvements in line operation reducing line trips, manifold over pressure and maintenance.

Control improvements implemented on a meter back pressure application has greatly reduced shipper line pressure cycling which was resulting in line trips under certain operating conditions.
Control improvements implemented on a holding pressure application greatly eliminated extremely high manifold pressure excursions during line rate changes and greatly improving the line operation at low rates. The line was not controllable under low line rates, resulting in the customer to consider other shipper options.

Boiler Optimization Surveys

ProNamics regularly conducts boiler and steam system optimization surveys. These surveys have shown that it is often possible to significantly improve steam system production and stability through control strategy upgrades, control loop health improvements and optimized controller tuning. Some of the results from our past surveys have included:

Increased black liquor firing rate
Increased hog fuel firing and reduced gas/oil usage
Improved steam header control performance and reduced pressure variability
Improved drum level control performance and reduced drum level trips.
Improved boiler efficiency

Our boiler surveys initially focus on the base level regulatory controls such as fuel and air flow controls, furnace draft, feedwater flow and drum level. This examination often reveals weaknesses in field instrumentation. Backlash and stiction in dampers and control valves, sensor calibration issues and poor tuning are typical findings during this initial phase. Once the base level controls are optimized the plant master and supervisory controls are evaluated. These advanced controls are often not setup to recongnize system dynamics and the limitations of the base level controls. Improvements to the advanced controllers are identified and implemented.

Please send us an email if you'd like to learn more about our approach to boiler optimization surveys and past results.

Control Valve Testing Kit

The ProNamics valve testing kit improves the ability of the E&I mechanic to evaluate and improve control valve performance. The kit is ideal for testing the performance of new or rebuilt control valves prior to installation and for testing valve performance during shutdowns (for valves difficult to test on the run). The kit can assist in evaluating control valve performance during normal operation, particularly when the process measurement is noisy or the process does not respond to small valve changes.

The system includes a 50 mm high precision LVDT that is capable of measuring valve position changes of 0.05%, a 4 to 20 mA transmitter, data acquisition cable and the necessary hardware for mounting to a variety of control valves.

ProNamics utilizes this valve test kit during our surveys and we’ve had great results. You can find more detailed information and pictures at

ProNamics Control Valve Test Kit

Petroleum Pipeline Pressure Control Optimization
ProNamics petroleum pipeline pressure control optimization services have resulted in dramatic improvements in line operation reducing line trips, manifold over pressure and maintenance. Our extensive knowledge of fluid dynamics, control valve dynamics and flow and pressure control have been integral to the successes achieved in our pipeline projects. Part of our ongoing projects with a major North American pipeline company is to validate the pressure control performance as determined by a dynamic simulation of the pipeline process.

ProNamics Control / Enero Solutions
ProNamics Control and Enero Solutions have agreed to partner on a range of process optimization activities. Enero Solutions is an energy consulting company offering auditing services, training and process simulations to assist clients in meeting their business objectives. Benoit Janvier, principal consultant, has over 8 years of steam plant optimization experience that includes on-site troubleshooting, control strategy optimization, and training. Much of this work has been in the pulp and paper industry. Contact us to learn more about our steam plant optimization services.

Process Troubleshooting Surveys
While ProNamics is known primarily as process control optimization specialists, our ability to troubleshoot process problems that are compromising product quality or process efficiency has always been one of our most important strength's. Process control is only as good as the process it is applied to and we spend a good part of the survey time troubleshooting process problems in order to optimize the controls.

The key requirements for successful troubleshooting are an analytical approach, an in-depth understanding of process fundamentals and equipment, and strong communication skills. High-speed data acquisition equipment and statistical methods to analyze trend data are important tools that can provide insight into the source of the problem. Without a strong understanding of process fundamentals, an ability to communicate effectively across a wide range of disciplines, and the proper tools, the troubleshooting effort will often be unsuccessful in identifying root cause or providing an enduring solution.

During these surveys, we work closely with the mill operators to define the problem clearly. Analyzing process trend data focuses the troubleshooting effort to a specific process area. Tests are designed to further isolate the source of the problem. Once the root cause is defined, we will ensure that the problem and the cause of the problem is communicated to all affected disciplines. We will work with the mill personnel to determine an enduring solution to the problem. We complete the troubleshooting survey with a detailed report documenting the tests and analysis conducted and the findings, recommendations and improvements. The report serves as a reference document for future problems.

Process Simulators
Dynamic simulation has recently emerged as an effective and affordable process optimization tool. There are many potential benefits, including improved process design, a faster and more analytical approach to process troubleshooting and more effective operator training. These important tools are underutilized in our industry. ProNamics Control Inc. has developed a series of first principles simulations that will minimize the barriers to mill application.

These 'unit operation' simulations cover pulp and paper processes from High Density Stock Systems to Paper Machine Dryers. The simulators have a graphical DCS-like interface that is ideal for use in a training environment. The process and control design is configurable, allowing the design engineer to test the impact of different equipment options or identify process limitations. Your process control specialist can explore controller-tuning options, investigate process non-linearity or study the impact of sensor re-location. Disturbances can be injected into the system, allowing the process engineer to conduct 'sensitivity' analyses or to understand key process relationships.

Please refer to the Process Simulators brochure for more details. Contact us if you would like more information or to arrange a site demo.

Chemi Washer Process Optimization Surveys
The objective of a ProNamics Chemi Washer process optimization survey is to increase operational efficiency in order to increase washer production, increase black liquor solids and improve product quality. These objectives will be achieved by reducing process variability in the key process variables.

ProNamics chemi washer optimization surveys have resulted in significant production increases through implemented control improvements to the stock feed consistency control and washer vacuum and level controls while maintaining black liquor and stock quality targets.

Refer to "Process Studies - Chemi" for more details or select ProNamics Chemi Washer Process Optimization

Variable Speed Drives
ProNamics presented a 'VFD Applications for Process Control' seminar at the TAPPI conference in March 2002. VFD technology has matured and now represents an attractive optimization option for pumping systems. VFDs not only provide energy savings but the potential for vastly improved control performance and lower process variability. ProNamics can assist you in identifying and quantifying the opportunities for VFDs at your mill. Find out more about the ProNamics 'VFD applications survey' from our survey menu. Download an excerpt of the TAPPI VFD seminar. If you would like to receive a full hardcopy of this seminar, please send us an e-mail.

Calculating Financial Benefits of Process Variability Reduction
The Pulp & Paper industry has experienced a significant economic downturn over the past two quarters. Reducing process variability is particularly important now because of it's potential to decrease operating costs and increase production rates. The low cost of conducting and implementing recommendations from a process variability survey compared to the large potential financial gains further increase it's importance. There are no set formulas for calculating the economic benefits of reducing process variability. The potential benefits are discussed in "Economic Benefits of Process Optimization and Reducing Process Variability", to be published in the January 2002 ISA PUPID Logger.

Improving control loop performance by retuning P I D controllers is the 'low hanging fruit' of process optimization surveys. There is minimal capital investment required, yet there is the potential for very substantial economic benefits. The retuned controller may be more capable of attenuating disturbances and keeping a key process variable on target. Alternately, implementing a tuning strategy which is based on optimizing the process objectives may move variability away from key processes. The retuned controller may reduce equipment wear and premature failure of loop elements. Whatever the case, the re-tuning effort can provide economic benefits by improving product quality and process efficiency, and reducing maintenance costs.

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