Guided Wave Radar Transmitters

By means of the radar wave technology of Honeywell’s SmartLine® transmitter, distributed exclusively in Italy by Precision Fluid Controls, it is possible to obtain accurate level measurement in every phase of the hydrocarbon refining process, with high levels throughout the plant’s cycle

by Vittoria Ascari

The refining process begins at the moment of the delivery of the crude fluid hydrocarbon at the plant, and carries on through the various phases which separate and optimize the plant’s final products.
A continuous flow and accurate monitoring of the process are fundamental. A reliable measurement level is essential to succeed in optimizing orders and delivery of stocks, and of additional chemical substances needed for the process. Reading the levels in real time allows to improve the capacity of the tanks, the control of the process and to guarantee protection in case of overfill. The variability of the sources and quality of stocks and the need for flexible, fast and convenient regulation imply the need for regulation instruments capable of managing different types of liquid within the same tank, and to ensure accurate and reliable level measurements. This is the case especially for the flow of stocks and for storage and process tanks of the various chemical substances used in the refining process. The presence of different liquids in the tank causes a change in the property of the liquids being measured; density, viscosity, flammability, storage temperature and pressure, dielectric constant and other properties will vary. This condition requires a universal measurement level immune to product variations, so as to ensure a fast and coherent adaptation to the process.

Maintenance and inventory costs reduced using level transmitters
Guided wave radar (GWR) technology is an effective solution to measure the level of liquids, even in the case of operations which involve the presence of hydrocarbons. It is a direct top-down technology which measures the distance at the surface of the product. Honeywell can count on a solid experience in the field, thanks to the SmartLine SLG700 range of level transmitters, offered on the Italian market by Precision Fluid Controls. These transmitters are designed to guarantee ease of use, reduced maintenance and contained inventory costs. One of the main advantages of the GWR solution is the internal level traceability algorithm, which guarantees the absence of impact deriving from fluctuations in pressure, temperature and conditions linked to the space of the vapour on the precision of measurement. A continuous and totally electronic level measurement allows to measure simultaneously both the level and the interface (separation). By means of internal calculations the SmartLine level transmitter can report, for a given tank, the level measured, distance, percentage, volume and mas (based on the filed conversion tables). Besides, SmartLine Connection Advantage, along with the Experion® monitoring system, offers messaging functions, maintenance method indications and tampering alarms which allow improvement of repair times and communication with the control room, hereby avoiding faults of the unit and increasing productivity The operator may take action more rapidly to prevent process issues.

Modular design for transmitters and level traceability technology
Just like all SmartLine devices, even level transmitters have a modular design which simplifies replacement operations and hardware updated on the filed even with reduced power. All of this does not compromise the general performances of the system or the certifications of the approval authority.
The instrument is equipped with a patented level traceability technology, which includes the automatic amplitude traceability function, allowing to trace levels continuously and reliably even if the amplitude of the level reflection varies on account of alteration of lots, turbulence or foam. Besides, the level measurement exploits the dynamic background function, which considerably reduces the maintenance efforts which would otherwise be necessary because of the build-up within the tank. Thanks to the advanced visualization and local configuration functions, by using the SmartLine level transmitter operators may solve any problems more efficiently. The display with advanced graphics shows the process data in graphic format and communication messages sent by the control room.

Ease in configuring and carrying out operations
Besides allowing configuration using any portable device by means of the new DTMs, users may configure the transmitters using buttons accessible from the outside even in an intrinsically safe environment. Configuration operations, changes in information or in the language used are simple to carry out, both from the work bench and on the field, and they do not require any portable device. The local level display allows visualization of the measurement values for the position of the flanges, the interface and the available volume levels. With user interfaces, such as the Experion monitoring system or DTMs, it is possible to visualize the entire echo curve by means of ordinary configuration tools, such as, for instance, Honeywell’s Field Device Manager (FDM). The SmartLine level transmitter uses an application validation instrument which simplifies the purchasing phase. Thanks to this online tool, users insert the technical data relative to the specific process tank, and verify that the correct level transmitter will be delivered on site ready to install. The plant’s personnel will then be able to entrust Precision Fluid Controls specialists by means of a joint online engineering session. l