Greg's Response:

Even a fast feedback controller is unable to get a compressor out of severe surge because of the huge jumps in flow. What is needed is an open-lo

Greg's Response:

The surge controller is a suction low controller with a remote set point that is parallel to the surge curve. Not only is surge prevented for all po

Russ' Response:

Yes!  It is very useful for some economic, operational, and control evaluations. Environmental vagaries would include continually drifting raw material

Greg's Response:

Equations have been developed to show the compressor map to the left of the surge point not commonly known that is the key to understanding the

Russ' Response:

Calibrate means to adjust coefficient values. In process instruments calibration usually means to adjust the zero and span knobs to convert the sensor response to the measurement (for instance conductivity to conce

Greg's Response:

Process simulations or plant tests can be run to determine the tray with the largest and most symmetrical (linear) response to a change in the sp

Greg's Response:

Dynamic simulations running faster than real time are key to ensuring the best column temperature controller tuning. Except for high purity

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

Greg's Response:

Dynamic simulations running faster than real time are key to ensuring the best column temperature control strategy. The manipulation of separ

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.

1. Inventory - Decide the inventory that
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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

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

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

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

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

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

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

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

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

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

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

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

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