We ask Greg:
What role do you see dynamic simulation playing in the future of best distillation column temperature controller tuning?
Greg's Response:
Dynamic simulations running faster than real time are key to ensuring the best column temperature controller tuning. Except for high purity
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We ask Russ:
How does one Test Dynamic Models?
Russ' Response:
Test means to review the model predictions (output values) with both data and logical expectations. If your model outputs adequately match the process data and expectations over a wide range of operating conditions, then you
...We ask Greg:
What role do you see dynamic simulation playing in the future of best distillation column temperature control strategy?
Greg's Response:
Dynamic simulations running faster than real time are key to ensuring the best column temperature control strategy. The manipulation of separ
...We ask Russ:
How does one develop First-Principles Dynamic Models numerically?
Russ' Response:
Here are eight steps in developing a dynamic model. Details and examples can be accessed under the Modeling/Simulation menu on my web site, www.r3eda.com.
- Inventory - Decide the inventory that ...
We ask Greg:
What role do you see dynamic simulation playing in the future of best distillation column pressure control?
Greg's Response:
Dynamic simulations can be help ensure distillation column pressure does not cause instability from operation at the weep point or flood point. The opera
...We ask Russ:
What are the pros for first-principles models?
Russ' Response:
Earlier I shared that I typically classify models as empirical or phenomenological.
In phenomenological models, the mathematical functions are grounded in a mechanistic relation. These models could be termed rigoro
...We ask Greg:
What role do you see dynamic simulation playing in the future of best crystallizer temperature control?
Greg's Response:
Batch-operated stirred cooling crystallizers are the most common type in the industry, but they tend to yield poor quality, primarily due to the high cooling
...We ask Russ:
What are the pros for empirical models?
Russ' Response:
I would broadly classify models as empirical or phenomenological.
Empirical models are developed by matching flexible mathematical functions to data. The functions might be neural networks, or classic statistical power
...We ask Greg:
What role do you see dynamic simulation playing in the future of best dryer temperature control?
Greg's Response:
The basic loop arrangement for dryer temperature control would use cascade control of outlet temperature to set inlet temperature. However, a constant outlet temper
...We ask Julie:
How has simulation contributed to operator training and control strategy development in your organization?
Julie's Response:
Many years ago, one site had an incident where an interruption in the flow of an organic fuel led to a deflagration. As a result, the operators always r
...We ask Russ:
Why use phenomenological models based on first principles over data-based modeling options?
Russ' Response:
I would broadly classify models as empirical or phenomenological.
Empirical models are developed by matching flexible mathematical functions to data. The functions migh
...We ask Greg:
What role do you see dynamic simulation playing in the future of best kiln and calciner temperature control?
Greg's Response:
In kilns and calciners, there are typically four zones. First is a drying zone of constant temperature, followed by a heating zone of rising temperature
...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
...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
...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
...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. Most analysis of processes and textbook instruction on how processes work use SS r
...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
...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
...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
...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
...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
...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
...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
...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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