Caldic adds radar for level measuring and data control

Redditch, UK -  Chemicals distributor Caldic UK Ltd, part of Rotterdam-based Caldic BV, has enhanced its stock management performance through the installation of  a TDR ( time domain reflectometry) radar level measuring and data recording system. The ATEX-certified system - designed, installed and commissioned by Hyconttrol of Redditch, UK - is monitorign nineteen 55,000 litre bulk storage vessels at Caldic's Chesterfield site. 

Caldic UK is focused on the storage, handling, blending, repacking and distribution of industrial chemicals for applications, ranging from petrochemical and refinery operations to cleaning products and water treatment. Typical chemicals which are being accurately measured include toluene, ethyl acetate and trichloroethylene.

Hycontrol's  multi-point VF guided wave radar units send low-power electromagnetic pulses of one nanosecond width along the instrument’s probe. Upon reaching the surface of the vessel contents, the pulses are reflected back with a signal strength that is dependent on the dielectric constant of the medium being measured. The instrument measures the time between the emission and the reception of the signal, converting this into a 4-20 mA output current. Weak or spurious signals are analysed and ignored by the electronics.

At the Caldic site, the level measuring transmitters are linked back via intrinsically safe barriers to a central control panel, incorporating a paperless chart recorder. This shows pictograms of the changing tank contents so that operators and management, either locally or remotely via the Caldic LAN, can readily see how much stock they have in real time.

According to Hycontrol, the TDR units provide an accuracy of better than ±3 mm over the 9.5 metre measuring range, while an external ATEX certified flashing beacon and siren warn of any potentially dangerous high level excursions in any of the tanks during filling.

Roger Collis, MD of Caldic UK, said: “Our previous vessel level measuring system gave very limited and often unreliable results. We needed to upgrade the instrumentation but were concerned about the disruption to production ... A key benefit of the TDR units is that they can be calibrated prior to installation. This removed the need for the tanks to be emptied and then filled to effect calibration, thereby causing minimum disruption to our plant operation.

Part of Caldic's stockholding is held on a consignment basis and the radar system provides important information for managing this, Collis continued. "We are confident that the availability of real time accurate level data will bring important efficiency and operational benefits to us and our suppliers, ensuring all parties concerned can optimise their production and delivery schedules.”