Fertilizer producer chooses wireless sensor solution

Wireless pressure and temperature transmitters send measurements via a self-organizing network that was easier to install and less costly than wired systems.
By Control Engineering Staff January 16, 2009

Soda Springs, ID — Nu-West Industries has chosen Emerson’s Smart Wireless platform to solve a complex reactor monitoring application. The vessel has 16 pressure and temperature monitoring points that need monitoring as part of the phosphate-based fertilizer manufacturing process. This has solved a logistical problem as the tank is in a difficult-to-reach area of the plant, about 250 ft from the control room.

“Hard wiring this installation would have been very challenging due to the location of the vessel,” says Brian Wood, DCS specialist for Nu-West. “Given the low-risk and simplicity of the application, this seemed an ideal place to try Emerson’s wireless package. The self-organizing architecture was the clincher since having a less than perfect line-of-sight to each device is not a concern with this system.”

Nu-West, a subsidiary of Agrium US , was interested in trying a wireless sensor approach, but it would have to be secure and reliable in operation over the extended distance and difficult location. The remote tank is 40 ft high and has four different beds of gases used to react with certain process chemicals. Even though this is not classified as a hazardous area, the tank layout and distance involved made running wires to the tank and mounting instruments both difficult and expensive.

Emerson says that each device in the wireless network can act as a router for other nearby devices, passing messages along until they reach their destination. If there is an obstruction, transmissions are simply re-routed along the mesh network until a clear path to the gateway is found.

Transmissions from the remote tank at Nu-West are received by a Smart Wireless Gateway and channeled via the PlantWeb control architecture to the DeltaV automation system.

—Edited by Peter Welander, process industries editor, PWelander@cfemedia.com ,
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