Sunday 22nd Sep, 2019

Pulsar’s ultrasonic success with super-light fumed silica measurement

When a Welsh silicon manufacturer couldn’t accurately measure its lightweight fumed silica, it reached out to Pulsar for a personalised solution.

When a Welsh silicon manufacturer couldn’t accurately measure its lightweight fumed silica, it reached out to Pulsar for a personalised solution.

Fumed silica is a common thickening agent, used in a wide variety of products from gel batteries to non-drip paint to a toothpaste abrasive or even as a light scattering agent in cosmetics.

It has a bulk density of around 30 grams per litre, with a surface area that can reach hundreds of square metres per gram.

Because the material is so light, it presents significant difficulties for bulk measurement. Silicon manufacturing company Cabot Carbon had begun running into these issues at its Welsh plant.

The company required accurate level measurement of its finished fumed silica product for stock control and to check tanker loads. Cabot Carbon tried a number of approaches to measure the contents, including radar, but all failed due to the lightness and absorbency of the product.

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Eventually, the company turned to Pulsar, which installed its non-conducting ultrasonic technology to monitor Cabot Carbon’s 11-metre-tall silo.

“The Pulsar equipment has cured a headache for us,” says Jason Jones, Cabot Carbon’s Electrical Engineer.

“We were really struggling to find something that worked and was cost-effective, and Pulsar’s kit ticks both boxes.”

Non-contacting measurement methods often rely on being able to bounce a signal back from a material surface and measure the time taken for it to reach the transducer. The challenge is to supply a signal with enough energy and then discriminate that signal against a background of competing noise.

Pulsar’s approach was to supply its highest power transducer, the dB50, along with an Ultra 5 ultrasonic control unit. The dB50 is designed to measure up to 50 metres and so puts a great deal of ultrasound energy into the measurement.

Even with that enhanced energy, the signal that returns to the transducer from the absorbent silica was small. To overcome this, Pulsar incorporated its latest generation Digital Adaptive Tracking of Echo Movement (DATEM) software to identify and dynamically track the material level.

The DATEM software maintains a link to the true material level, even as it changes and other signals from the internal features of the vessel compete.

Bintech Systems is the Australian distributor of Pulsar products. The company offers level measurement devices from a number of different suppliers, which helps it provide the best fitting solution for its customers.

The company prides itself on its personalised services and offers on-site commissioning telephone assistance, workshop repair, servicing and calibration services.