LOAD CELLS BRING PRECISION WEIGHING TO PORTUGUESE PVC PLANT

Precision weighing equipment from Thames Side Sensors has transformed the tanker-loading process for a major producer of PVC in Portugal.   Installed on new and existing silos, the British manufacturer's load cells now ensure highly accurate out-loading of PVC powder from the CIRES plant at Estarreja in western Portugal.

Supplied through Bristol-based silo manufacturer Braby, the load cell assemblies form part of a £1.5 m contract for storage and handling equipment.
This includes three new aluminium silos standing 28 m high and 5 m wide, each of which is able to hold approximately 300 tonnes of PVC powder.   These are mounted on twelve Thames Side Sensors VC3500 load cell assemblies which are designed especially for high capacity vessels and individually rated to 100 tonnes.

Because of the exceptional height of the silos, the impact of wind displacement on weighing accuracy was an important consideration when the units were specified.   However, pre-installation tests using Finite Element Analysis (FEA) showed that the loading assemblies, which are designed with an integral lift-off prevention feature, would return consistently accurate readings despite the silos' size.

In addition to the VC3500 units, Braby has supplied 64 Thames Side Sensors T40 loading assemblies for retrofitting to 8 stainless steel silos already used at the CIRES plant.   The T40 units, which are individually rated to 25 tonnes, provide a more accurate replacement for the high-level measuring probes previously used to gauge the contents of the silos.

CIRES - the Companhia Industrial de Resinas Sintéticas s.a. - is Portugal's only PVC manufacturer, and specialises in the production of suspension and emulsion PVCs (S-PVC and E-PVC respectively).   The S-PVC stored in the silos at Estarreja has a wide range of applications including cable insulation, hoses and rigid mouldings.   The company's total annual production is approximately 130,000 tonnes.