Lion Oil adds wireless technology at US facility
7 May 2010
El Dorado, Arkansas – Lion Oil is using Emerson’s Smart Wireless technology to check product inventory, prevent overfill and remediation costs, monitor UPS power for the radio tower, and monitor safety shower use in areas over 1,600 feet from the control room at its El Dorado facility.
The nine Smart Wireless applications cost $165,000 less to install, set up, and commission than traditional wired networks and has saved the company $20,000 in operating costs, according to an Emerson press statement.
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’ 4-20 milliamp signal 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 were also installed to measure temperature on a crude oil storage tank as well as a slop oil tank.
The company installed three wireless Rosemount 702 discrete switches on safety showers in three remote areas. The switches alert operators when a shower has been turned on so they can send help. Another wireless discrete switch was installed on the UPS (uninterruptible power supply) for the radio tower because of the distance from the control room.
“A wireless solution was required because of the long distances; a wired solution was not even considered” said Wilson Borosvskis, Lion Oil instrumentation and control engineer.
Due to the large distances involved in all the measurements, two additional wireless Rosemount temperature transmitters were installed as signal repeaters. All 14 devices form a self-organising 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.
“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,” said Borosvskis. “The discrete switches on the showers would easily have cost $10,000 each to wire.”
The sodium hydrosulfide level information sent to the control room from the wireless transmitter has an additional benefit. “Sodium hydrosulfide is a by-product that is sold to a local company, who sends trucks to this remote tank to be filled,” said Borosvskis. “The company that buys this by-product can remotely monitor the level, to prevent sending trucks out when the tank is empty”.
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.
