Nov
28
At Emerson Exchange, 2011, I had the pleasure of working with Frank Seibert, Technical Manager and Eric Chen, Associate Researcher, Pickle Research Center, University of Texas at Austin SRP and John Caldwell, Advanced Control Marketing Manage, and Willy Wojsznis, Senior Technologist, Emerson Process Management, to host a workshop that addresses how data analytics may be …
Nov
14
At Emerson Exchange, 2011, I had the pleasure of working with Daniel Coyne, Manager, Automation, BP America Inc., to host a workshop on Recovery from a Process Saturation Condition. The workshop addresses the improved recovery from a process saturation condition that is provided by the PIDPlus option of the PID function block in the DeltaV …
Oct
27
Heat exchangers in a coil or jacket recirculation system are used to provide tempered water. This allows the use of colder or hotter utility streams as inputs to exchangers rather than as inputs to a coil or jacket, moderating temperature extremes that could cause heat transfer surface coatings or product degradation from localized cold and hot spots …
Oct
20
Heat exchangers in a process recirculation steam are also used for reactor temperature control. The high velocities on the process side in the exchanger increase the heat transfer coefficient and reduce fouling. For cascade control the reactor temperature PID output is the setpoint of the exchanger outlet temperature. For the exchanger to do its job …
Oct
17
This year Emerson Exchange will be held October 24-28 at the Gaylord Opryland Resort & Convention Center in Nashville, Tennessee. Emerson Exchange is a forum for the free exchange of non-proprietary information among the global user community of all Emerson Process Management’s products and services. The technical sessions in this conference cover a wide range of industry …
Oct
12
Whether the secondary loop uses coil or jacket inlet or outlet temperature is often a matter of tradition for a particular company or process industry. The dynamic response of the cascade control system to reactant disturbances such as feed and reaction rate are the same for jacket inlet and outlet temperature control. However, the coil or …
Oct
06
The cooling and heating system is critical for reactors since temperature plays such a huge role in determining reaction rate and selectivity (formation of desired product). The limit to what a valve position controller (VPC) can do to increase production rate depends upon the capability of the cooling and heating system. The system can also be the …
Sep
29
Batch and fed-batch reactors are designed so that the product concentration is always increasing in the reaction phase of the cycle whereas continuous reactors are designed to hold a constant product concentration. These fundamental differences have enormous implications in terms of composition control. Conventional control of product concentration in a batch and fed-batch reactor is …
Sep
23
Reactors are the pivotal unit operation that sets plant capacity and efficiency besides product quality. Reactors provide good examples of the common and distinctive opportunities for the PID control of batch, fed-batch, and continuous unit operations. Here we examine pressure, temperature, and endpoint control. The pressure control of batch, fed-batch, and continuous reactors may have …
Sep
16
Batch and continuous temperature loops can have vastly different responses. Fortunately, temperature loops have a characteristic early in the response that enables a fast identification of the process dynamics. The resulting models can be used for process control improvement, tuning, and rapid deployment of models for plantwide simulations. Temperature is the most important common measurement …
