Inventory Control Gas Tank Farm
Back To [Automation Articles]
"It's all in the mix"
Endress-Hauser uses new instrumentation to make sure that the hydrocarbon composition in the gas tank farm of solvadis cpc GmbH is correct and that the required safety standards are met. Installing Proservo high-pressure level instruments and the FuelsManager inventory software solvadis has paved the way for the future.
The Krefeld based solvadis cpc GmbH supplies hydrocarbons of any composition used, for example, as an environment friendly and non-toxic propellant in sprays, solvadis has many years of experience in highly volatile hydrocarbons. Its service program comprises the production and sale of aerosols as well as the storage and distribution of specialty gases.
Since hydrocarbons may be mixed with each other in any proportion, compositions are realised accordingto customer requirements and legal provisions. The resulting product, AeronÂ©, is used as a propellant, refrigerant or inflating agent.
Materials and products arrive by ship and are stored in horizontal tanks of 60 m in length and a diameter of 6 m. Servo and radar Instrumentation not suitable for custody transfer has been used previously.
Data was visualised by a display and manually entered for processing. Authorities required the instrumentation and data evaluation to be adapted to the latest standard and safety regulations.
The horizontal tanks are slightly inclined with their instruments at the highest point. This causes a dead space which cannot be measured. To minimise the dead space, the instrument must be able to measure right down to the bottom of the tank in ahighly precise fashion.
solvadis chose Proservo NMS of Endress-Hauser because this precision enterprise does not only have a convincing performance in the area of instrumentation but also in inventory control.
Media properties (low dielectric constant) decided for Proservo as compared to other measuring principles. In addition, Proservo guarantees highly precise measurement in liquid gas tanks right down to the bottom.
The liquid gas mass calculation was realised by FuelsManager Endress-Hauser software. solvadis uses SCADA software -FuelsManager- for safe and fast data exchange with the higher-ranking system via an OPC client/server. This guarantees the compliance with official requirements for solvadis. In addition, productivity and safety are improved.
The Proservo tank measurement system is based on the displacement method. A small displacer is precisely positioned in the liquid using a servo motor. As soon as the level of the liquid rises or falls, the drive motor tracks the displacer position. The rotation of the calibrated drum is evaluated to determine the level with an accuracy of up to Â± 0.7mm. Additional variables like interface and density measurement of individual layers do not present any problem to Endress-Hauser Proservo.
The FuelsManager SCADA software calculates the liquid and gas phase mass of liquid gases from level, pressure, temperature and, ofcourse,densityvalues. The level measured above Proservo is read invia the RTU8130 Endress-Hauser fieldbusinterface. Theotherprocess data, pressure and temperature enter the system via the opeclient/server interface. Afterdata hasbeencalculatedthere,itis available to the higher-ranking system.
The accuracy of the instrumentation installed as well as the FuelsManager calculations are more precise than the values demanded by authorities. solvadis now has a modern server/workstation concept. SCADA functionality permits the integration of pumps, valves or PLCs. Groups of tanks may now be displayed
graphically or in form of tables and every screen can be adapted to individual requirements. Endress-Hauser makes sure current inventory data is available and safely integrated.