In South Africa, where local mills must remain competitive in a global industry, reliable instrumentation is vital to ensuring operational efficiency and maintaining product quality, says process instrumentation sensor developer Vega Instruments group marketing manager Miguel Petersen.

He explains that the paper manufacturing process is a demanding operation that relies on consistency, precision and control at every stage.

“From the preparation of raw pulp to the continuous operation of bleaching towers and storage systems, each phase presents unique measurement challenges,” he adds.

Importantly during stock preparation, pressure screens are tasked with removing contaminants and filtering out usable fibres.

With constant pressure changes, abrasive materials and flow variability, these units require accurate pressure monitoring.

The VEGABAR 82 pressure transmitter is well-suited to these harsh environments, offering a robust ceramic measuring cell that delivers stable readings even in the presence of pressure surges and solids-laden media.

“Maintaining the correct pressure differential across the screen is critical and continuous monitoring helps ensure that only clean, well-prepared stock moves forward in the process,” stresses Petersen.

Bleaching

The bleaching stage involves the use of strong oxidising agents such as oxygen, ozone or hydrogen peroxide to remove lignin and whiten the pulp.

These chemicals are introduced into towers that are 25 m high and operate continuously at temperatures close to 95 °C.

“Given their size and operational demands, these towers are never emptied and require continuous level monitoring.”

In this application, a combination of Vega’s VEGAPULS 6X, VEGABAR 82 and VEGACAP 64 instruments provide reliable measurement data to the operator.

The VEGAPULS 6X, with its radar-based, non-contact level sensing, handles high temperatures and steam-laden environments without loss of accuracy, while the VEGACAP 64 – a capacitive level switch – adds redundancy and ensures safe, reliable operation under variable conditions.

“Together, these instruments allow process engineers to maintain chemical dosing and pulp consistency at optimal levels, avoiding overflows, dry runs or chemical waste,” Petersen comments.

No Blockages

Petersen says that at the start of the papermaking process, wastepaper or pulp bales are introduced into the pulper by conveyor belts, where they are combined with process water and broken down by mechanical stirrers.

“The aggressive motion of the stirrers, coupled with possible foreign objects like wires or metal debris, creates a demanding measuring environment,” he says, adding that in this instance the VEGAMIP 61 and VEGABAR 82 are critical instruments used to prevent breakdowns.

For these conditions, the VEGAMIP 61, a microwave-based sensor, provides non-intrusive level detection, even through thick vessel walls or turbulent product surfaces, which, when used in conjunction with the VEGABAR 82, allows for accurate detection of water-to-fibre ratios, to maintain fibre consistency.

“Additionally, conveyor monitoring with VEGAMIP ensures that blockages or jams from bale congestion are quickly identified and addressed before they cause downtime,” says Petersen.

Once prepared, the stock is stored in large vertical towers with high throughput.

Constant agitation within these towers ensures homogeneity, but also creates turbulent surfaces, foam and steam, all of which interfere with less capable sensors.



Designed for difficult conditions, the VEGAPULS 6X provides accurate, continuous level readings regardless of condensation or agitation.

When paired with VEGABAR 82, which can handle temperature fluctuations and mechanical stress, this setup helps avoid dry running of agitators, ensures consistent material availability and prevents unplanned stoppages in the production line.

Vega Instruments’ Input/Output-Link, myVEGA and non-contact radar, meanwhile, keep calibration and diagnostics friction-free.



This connectivity supports more agile operations, where maintenance teams and operators can make process adjustments in real time or access diagnostics without delaying the process, Petersen adds.



With the range of instrumentation offered by Vega Instruments, South African mills are better equipped to meet the demands of both local and global markets.

“These tools support better decision-making, reduce production risks, and enable smarter, more resilient operations from pulp to finished product,” concludes Petersen.