We ask Julie:
What strategies have you found effective for starting small, low-risk simulation projects to build credibility and trust?
Julie's Response:
Back in 2019, the new DuPont was formed after the merger and split with Dow. Many sites were struggling to continue their migration proje
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We ask Greg:
What role do you see dynamic simulation playing in the future of best vessel temperature control?
Greg's Response:
A vessel is defined here as storage, recycle, blend, or surge volume where there is no heat of reaction and no agitator. Fortunately, most vessel volumes are so la
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We ask Russ:
What are some of the benefits of dynamic simulation over steady state simulation?
Russ' Response:
Traditionally, process design uses steady state (SS) simulation, and it serves its purpose well. Â Most analysis of processes and textbook instruction on how processes work use SS r
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We ask Greg:
What role do you see dynamic simulation playing in the future of best heat exchanger temperature control?
Greg's Response:
Flows much lower than design causes a high process gain and high process deadtime that can lead to temperature oscillations and possible instability. Low v
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We ask Greg:
What role do you see dynamic simulation playing in the future of best temperature measurement installation?
Greg's Response:
Temperature RTD sensors should use 4 wires and TC sensors should use extension wires of same material as sensor with length as short as possible to minim
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We ask Greg:
What role do you see dynamic simulation playing in the future of best temperature measurement selection?
Greg's Response:
Temperature is often the most important of the common measurements because it is an indicator of process stream composition and product quality. Temperature
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We ask Greg:
What role do you see dynamic simulation playing in the future of best lime system design for pH control?
Greg's Response:
Lime feeders have a transportation delay that is proportional to the length of the feeder divided by its speed. This transportation delay may be several min
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We ask Greg:
What role do you see dynamic simulation playing in the future of best liquid reagent dilution for pH control?
Greg's Response:
A common misconception is that the slope of the titration curve and, therefore, the system sensitivity can be decreased by reagent dilution. Reagent di
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We ask Greg:
What role do you see dynamic simulation playing in the future of best liquid reagent delivery for pH control?
Greg's Response:
If the reagent pipeline is partially filled or empty or a dip tube is backfilled with process fluid, the regent delivery delay becomes the biggest sour
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We ask Greg:
What role do you see dynamic simulation playing in the future of best reagent selection for pH control?
Greg's Response:
For a reagent dose to be precise enough, the reagent’s logarithmic acid dissociation constant (pKa) should be close to the pH set point so that it tends to f
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We ask Greg:
What role do you see dynamic simulation playing in the future of best control valve deign for pH control?
Greg's Response:
Stick and slip generally occur together and have a common cause of friction in the actuator design, stem packing, and seating surfaces. Rotary valves with
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We ask Greg:
What role do you see dynamic simulation playing in the future of best static mixer use for pH control?
Greg's Response:
Static mixer have noisy pH measurements. Signal filtering can help but a downstream volume is needed to provide smoothing of pH oscillations that can be large
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We ask Greg:
What role do you see dynamic simulation playing in the future of best vessel design for pH control?
Greg's Response:
pH systems are extremely sensitive to the vessel design. A poor design can make good pH control impossible in nearly all systems despite the use of the most adva
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We ask Aaron:
You’ve mentioned the desire to avoid “replacement in kind” and to deliver ROI a couple of times.  It’s not intuitive where that return would come from on a DCS replacement project – where is the value? What’s the role for simulation there?
Aaron's Response:
When we talk about
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We ask Aaron:
How has dynamic simulation changed the way you approach control system upgrades?
Aaron's Response:
Fundamentally, I think this is a two-way street. The way that simulation has changed the way I approach system modernization projects has shifted almost hand-in-hand with the wa
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We ask Greg:
What role do you see dynamic simulation playing in the future of best titration curve critical for pH system design?
Greg's Response:
The titration curve is the most important piece of information for designing, commissioning, and troubleshooting pH control systems. Lab titrati
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We ask Aaron:
What is the role of dynamic simulation in control system modernization?
Aaron's Response:
In control system modernization projects – that is, brownfield projects designed to replace and improve the automation systems in plants – the focus is on risk.  Risks come from changes
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We ask Greg:
What role do you see dynamic simulation playing in the future of best minimization of pH system cost?
Greg's Response:
Because of the pressure to minimize capital costs, a project may sell itself short on the number of stages required. The basic rule from the 1970s was that a w
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We ask Greg:
What role do you see dynamic simulation playing in the future of developing the best maximization of reactor production rate?
Greg's Response:
Production rate can be maximized by a valve position controller (VPC) monitoring coolant valve position. The VPC setpoint is the maxim
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We ask Greg:
What role do you see dynamic simulation playing in the future of developing the best fluidized bed gas reactor temperature control?
Greg's Response:
For gas reactants and a gas product, a pressure loop controls the material balance and provides the time available for reaction
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We ask Greg:
What role do you see dynamic simulation playing in the future of developing the best multiphase reaction completion control?
Greg's Response:
For both batch and continuous reactors, reaction completion control seeks to provide a complete conversion of all reactants and consequ
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We ask Greg:
What role do you see dynamic simulation playing in the future of developing the best liquid single phase continuous reactor composition control?
Greg's Response:
For reactions that are all in one phase (gas, liquid, or solid), inventory control (pressure or level control) canno
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We ask Greg:
What role do you see dynamic simulation playing in the future of developing the best liquid single phase continuous reactor temperature control?
Greg's Response:
Temperature loops control the energy balance and the reaction rate through the Arrhenius equation. A cascade tempera
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We ask Greg:
What role do you see dynamic simulation playing in the future of developing the best Flow Measurement Specifications?
Greg's Response:
Lack of recognition of the adverse effects of changes in process stream composition and operating conditions, upstream and downstream piping, a
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