Emerson Process Management’s Smart Wireless network has replaced local hardwired high-temperature trip protection on 20 hazardous duty chemical pumps at the Dyno Nobel Inc. ammonium nitrate production facility at Louisiana, Missouri. The new Ammonium Nitrate Pump High Temperature Protection & Monitoring System has produced a significant improvement in plant safety, increased operator awareness of the condition of these pumps, and reduced the potential for plant or environmental damage due to a fire and/or chemical release. In addition, the company saved $30,000 to $40,000 on system engineering and installation.
The new WirelessHART network, comprising 20 new Rosemount wireless temperature transmitters and 20 new Rosemount wireless discrete switches plus dual-element temperature sensors and high-temperature switches, extends about 1500 feet from end-to-end. The transmitters are connected by a self-organizing wireless mesh network to one Smart Wireless Gateway which relays the data to a DeltaV digital automation system for monitoring, alarming, and trending purposes. The wireless discrete switches transmit system “fault” and high temperature “trip” signals from the temperature switches to the DeltaV console, where operator graphics display temperature and switch data for each pump along with a wireless network overview and status screen for operations and maintenance personnel.
If the discharge temperature of a pump rises beyond the safe operating setpoint, a high alarm is issued by the DeltaV system. If the temperature continues to rise, the DeltaV system issues a high-high temperature alarm to notify operators that the temperature at that pump is reaching a dangerous level. If the temperature rises still further, the local high temperature switch shuts the pump off before it reaches the critical temperature at which the ammonium nitrate could begin to decompose. Operators are alerted to a safety trip fault by a signal from the discrete wireless switch.
Emerson’s AMS Suite predictive maintenance software sends predictive diagnostics generated by the smart field devices to operations and maintenance so a high temperature alarm condition can be addressed before a safety trip is required. In addition, the AMS Wireless SNAP-ON application aids in planning, installation, and diagnostics of the wireless network. All of the devices on this network were powered up and commissioned in just one day in July, 2009.
According to Dyno Nobel plant operations manager Sam Correnti, “All the factors
