Wireless Technology Helps Lion Oil
Called Smart Wireless, Emerson Process Management’s wireless technology designed to the IEC-62591 WirelessHart standard cost $165,000 less to install, set up and commission than traditional wired networks. In addition, the wireless solution has saved the company $20,000 in operating costs, according to the two companies.
Lion Oil connected three of Emerson’s wireless Rosemount 648 temperature transmitters to radar level gauges on an asphalt storage tank, a sodium hydrosulfide tank and a crude oil storage tank. The wireless temperature transmitters scale the gauges’ 4 to 20 mAsignal to send a level measurement to the DeltaV control system. The information provides a redundant measurement of tank levels to prevent overflow and provide a check for the custody transfer of asphalt. Two wireless temperature transmitters also were installed to measure temperature on a crude oil storage tank as well as a slop oil tank.
The company installed three wireless switches on safety showers in three remote areas that alert operators when a shower has been turned on, so they can send help. Another wireless discrete switch was installed on the uninterruptible power supply for the radio tower because of the great distance from the control room. Due to the large distances involved in all the measurements, two additional wireless Rosemount temperature transmitters were installed as signal repeaters. All fourteen devices form a self-organizing field network and transmit their signals to a Smart Wireless Gateway. The gateway sends the data to the facility’s DeltaV digital automation control system also from Emerson.
“These tanks are isolated from process areas where we have available junction boxes for conventional I/O. The wiring and conduit required for a traditional network would easily have cost $135,000 for the three tanks,” says Wilson Borosvskis, Lion Oil instrumentation and control engineer.
In another plant area, the company installed two wireless Rosemount temperature transmitters to monitor a crude oil tank and a slop oil tank. Temperature is critical to calculate the correct volume of oil. The company estimates it saved $150 per day in operations costs - nearly $20,000 total - by installing wireless on the slop oil tank. The temperature sensor on the existing transmitter that measured both level and temperature had failed. The temperature sensor could not be fixed until the tank was emptied during turnaround, four months later. The plant saved the operators two trips a day for four months to read and record the temperature, and calculate the volume.