18 February 2009

Most industries involved with bulk materials are familiar with the frustrations of continuous belt weighing. Load cell support structures become clogged with product and require regular cleaning, and accuracy drift as a result of load pounding on the load cells necessitates frequent calibration, causing losses due to downtime and the interruption of the production process.

However, Tshwane-based Rand Technical Services offer Procon inflo belt weighers that operate without load cells, obviating these problems and delivering a precise, consistent accuracy that requires very little maintenance. This is according to Ian Fraser, Managing Director of RTS.

Says Fraser: “Procon belt weighers are used throughout the world in countries such as China, Sweden, United Kingdom, Scotland and the United States. Suitable for the toughest, harshest environments, they function throughout a broad industry spectrum- particularly in mining, quarrying, power generation, pharmaceutical, chemical and general engineering. Materials weighed range from coal to chemicals, ore, crushed stone, cement and even food processing.”

Fraser continues: “At the heart of the Inflo Resometric belt weigher is the Digital Resometric Force Transducer, or resonator, which provides high measurement performance levels over a long working life. With no moving parts, the fine wire of the resonator is tuned to the standard, zero-weight level of the applied force from the weigh carriage itself.

This resonant frequency then changes in proportion to the weight of the load passing over the carriage rollers. The change in frequency is measured and processed by the electronics and, when combined with the belt travel speed (as measured by a tachometer) provides an accurate weight reading per unit time.”

As there is minimal physical stress on the resonating wire itself, it suffers little wear and tear, and retains accuracy for long periods of time. Nevertheless, roll-over calibration weights allow for easy, periodic calibration checks. Normally parked across the conveyor stringers, these dead weights are easily and simply lowered by a cam mechanism whenever calibration is required, and provide a good indication of the measurement consistency achieved.

Interference from poor belt tracking, or badly aligned loads, is prevented by the lateral chains fitted between the weigh carriage and the rigid conveyor. These chains ensure that, once the weigh carriage has been installed and aligned, it will only be sensitive to vertical forces.

Inflo belt weighers have also been used extensively on mobile equipment such as ship loaders and stackers or reclaimers. Despite the belt weighers being continually subjected to changing angles of operation, no significant cosine weighing errors occur. Procon’s proprietary Astatic Mass Zero Compensation system automatically compensates for the changing angles, ensuing accurate weighing of the suspended weigh carriage mass.

The Inflo belt weigher meets international weights and measures requirements, and is certified according to OIML recommendation R50 (continuous totalising automatic weighing instruments.)

Concludes Fraser: “RTS service backup and service optimizes an already robust product. This technology is relatively new to the local market, but it is well-known, and well-proven internationally, under a broad range of operating and climatic conditions. Saving time, downtime, resources and maximising profit for our customers, the belt weighers allow highly accurate commercial product transfer and supply for anything from power station coal stocks and iron ore, to agricultural produce such as wheat or sugar. The applications for this innovative technology are almost endless.”

-Ends-
(563 words)

Note to Editors

Rand Technical Services, or RTS, is a specialised, Tshwane-based company offering innovative technologies and solutions to industrial problems.

Run by Managing Director Ian Fraser since its inception in the early 1990’s, the company offers globally-sourced, quality products such as continuous belt weighers without load cells, laser-based gas detection devices for hot or corrosive areas, and electrolysers for hydrogen production.

Product delivery and technical consultation by highly-trained staff is offered throughout Southern Africa to a range of clients in industry sectors such as mining, glass, steel and energy.

Editorial Contacts

Richard Cooper
Marketing manager
Rand Technical Services
012 - 993 9620
info@rtsafrica.co.za
www.rtsafrica.co.za

Kendal Hunt
PR Consultant and Writer
Kendal Hunt Communications
011 – 7045649 or kenh@mweb.co.za