Enabling process optimisation with optek inline control

For over 30 years, optek has focused on measuring process liquids through its interaction with light in facilities all over the world. Although global, optek remains a family-owned company with a team of more than 100 qualified, customer-driven professionals. With the expertise of more than 30,000 installations worldwide, the company’s value to the customer resides in providing a superior product that pays back. High-quality materials withstand the toughest process conditions including aggressive media, high temperature, and high-pressure applications.

Cleanability is ensured using high-quality wetted materials, superior design, as well as sapphire optical windows. As a global partner to various industries, optek offers advanced technologies including superior signal amplification, inline calibration support, PROFIBUS PA, FOUNDATION Fieldbus and multilingual user interfaces for easy onsite operations. The company’s support provides long-term satisfaction with programs such as “Speed-Parts” and “SwapRepair” to provide sustainable operations and minimised downtime at a low cost of ownership.

Colour measurements

Process colour measurements of liquids are critical in maintaining precise process control and meeting product quality specifications. Colour changes indicate other process variables such as overheating, dilution ratios, dissolved impurities and finished product appearance. Monitoring colour inline using optek photometers enables precise, real-time control of colour dosing, colour removal or colour avoidance.

Dual wavelengths

Selected combinations of optical filters make it possible to focus on specific wavelengths ensuring suitable adaptation to the application. The AF26 is equipped with a beam splitter making it possible to measure two wavelengths simultaneously. The second wavelength can be used to compensate for (varying) background turbidity. Subtracting the absorbance signal of the reference channel from the primary, visible channel signal gives a pure colour measurement. Using the C4000 converter, the measured value is easily correlated to any required unit, such as APHA/Hazen, Saybolt, ASTM, ASBC, EBC, ICUMSA or others. The converter displays the measurement locally and transmits the signal to a PLC or DCS using analogue outputs or PROFIBUS PA communication or FOUNDATION Fieldbus.

Concentration measurement

The measurement is represented in concentration units (CU) at a given wavelength and relates to the concentration of constituents in question that interact with light.

Process optimisation

The detection of impurities, reduction of product losses and the real-time assurance of product quality can be obtained by the use of inline photometers. In addition, inline photometers greatly reduce laboratory and production costs, eliminate human error and prevent environmental damage.

Clean-in-place (CIP)

Many manufacturing facilities require CIP systems to clean tanks, pumps, valves, filters, heat exchange units as well as the process piping. The use of CIP increases plant efficiency, improves safety and ensures product quality. However, achieving these benefits requires monitoring and control of the CIP process to optimise heat, cleaning agents and water consumption.

CIP optimisation

Precise process interface detection with a single channel NIR absorption based photometer (optek AF16-N or AS16-N) is typically installed at the CIP return points where it is beneficial to measure the exact interface on rinse water. Inline photometers can also be used to monitor the sanitiser concentration to control the CIP process, for validation routines, and in some cases, to monitor the residual after cleaning.

Sanitiser concentration

Chemical concentration has always been a difficult measurement using traditional conductivity sensors. Changes in pH, temperature, or other unexpected compounds can all affect conductivity devises. To compensate for these issues, plant operators often overdose chemicals to ensure adequate sterilisation, then extend line flushes to ensure it is removed.

Sanitiser optimisation

By installing an optek UV/VIS or NIR absorption sensor on the feed line, exact concentrations are monitored, optimising performance, while reducing chemical usage. These sensors are also compensated to eliminate any influence from turbidity or the presence of other compounds. In addition, with immediate response times, sanitiser and water usage is greatly reduced.

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