High Density Temperature Measurement Applications

High density temperature transmitters have many applications in process plants.  These are commonly found on distillation columns to monitor the temperature profile.  The advantage is that multiple temperature measurements can be achieved through one transmitter.  Rather than running a RTD wire from a process to a marshaling cabinet, a high density transmitter can reside near the process with a single wire .  This saves on installation and wiring costs as instrument wire is less expensive that RTD wire.  It is also easier to maintain as RTDs can be replaced much easier.  This same solution can be used for reactor temperature monitoring and control.

Often times a chemical reactor will develop a temperature profile.  Any deviation from the temperature set point can have negative effects on the reaction.  If the temperature is too low, the reaction may not occur.  A high temperature can cause the reaction to occur to quickly or damage the finished product.  In polymerization reactions a high temperature can plug your process.  While it is common to have a single temperature measurement, it only measures a single point in the process.  A high density temperature measurement will allow you to monitor what happening throughout your reactor.

Because a high density temperature measurement uses RTDs rather than individual transmitters, the solution can be used internal to the reactor.  Rather than having RTDs along the reactor wall, a probe can be inserted internal to the vessel.  Using a wireless solution, the RTDs and transmitter can be installed along the shaft of a mixer.  A temperature measurement at the center of the reactor can provide a significant benefit.  For a full temperature profile, have RTDs both internal and along the wall is a solution that should be considered.

Along with providing a monitoring and control measurement there are several other benefits this solutions can provide.  First, it can detect hot spots in the reactor.  This can alert you to a blocked line in a steam jacket or missing insulation.  Second, it can alert you to missing impeller blades on the mixer.  If the product is not being agitated, the internal temperature will be different than the wall temperature.  Finally, a temperature deviation can let you know when additional products should be added, either to slow down or speed up the reaction.

Reactors can benefit significantly with a high density temperature measurement.  It helps you maintain your process control.  It can also provide diagnostic information to detect other process problems.  The best part is they are fairly inexpensive to install and maintain.

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