Optimising the Wastewater Treatment Processes

August 3, 2021 7:34 pm

Measurement Challenges in Wastewater Treatment.

Continuous level measurement forms a critical part of the optimisation of wastewater treatment plant processes. Level measurement technologies are part of wastewater treatment applications at various points like inlet pumping stations, sludge treatment, primary and secondary clarifiers, and at the rakes. Level monitoring is a key factor in optimising overall operations at the sewage treatment plant and thereby effectively controlling the cost of the wastewater treatment.

However, level monitoring at the wastewater plants is not as easy as controlling the level in drinking water plants. Sewage treatment plants pose a particular challenge with all kinds of waste products like tissue and fatty food wastes. Along with these substances, the problem is aggravated by the formation of gases and thereby frothing on the surface of the water as well as changing temperature conditions when water flows through open channels. This also makes the microenvironment in wastewater volatile and one can see the changing temperature and pressure conditions while processing such wastewater.

Traditionally, most wastewater treatment plants rely on ultrasonic sensors for level measurement in the processes. However, ultrasonic technology is susceptible to most of the challenges that are already mentioned, which makes the measurement unreliable and inaccurate. Unreliable and inaccurate measurement equals an unoptimised process and increased cost of operation. Now, radar technology has come to its age, which not only addresses all the challenges but it’s also become affordable and cost-effective.

Radar sensors and Waves

Moving surfaces are a common sight in water level applications. Especially in wastewater treatment, water may be constantly flowing or getting stirred, creating a lot of turbulence. However, radar sensors are immune to these and they can reliably measure the level regardless of the water movement.

VEGAPULS Sensors: Keeping check on the ‘Cost’

VEGA developed its prolific radar technology in order to optimise the wastewater treatment processes to reduce the cost of its operation, decrease the energy utilisation and reduce the overall maintenance cost. It was possible due to the new microchip, which is the heart of its new technology. With this new microchip, new VEGAPULS sensors are able to address the cost-sensitive applications in the water industry by keeping the costs of new radars at par with ultrasonic sensors.

Robust and weatherproof design, Reliable Measurement Due to process conditions, sensors are often submerged in water. Mechanical flood protection sleeves in ultrasonic sensors can easily get soiled in such conditions. In contrast, radar sensors from VEGA do not require such protective sleeves as they can operate reliably even when they’re flooded, hence, the maintenance cost is reduced as well. This also takes us to make a special note of VEGA’s radar sensors that have no dead zones and they can measure reliably right up to the top of the vessel where they’ve been deployed.

Focusing: Key to Reliable Measurement

In a wastewater treatment plant, many applications can be found where the level control has to be done in a very small place, such as well, water collection tank. Such small vessels can also form a part of additive storage tanks, which have to be added during the water treatment process at a precise time and in a precise volume. Such vessels can also have internal installations, and if the sensors are installed on these vessels, the measurement may get affected. However, with VEGA’s new 80 GHz VEGAPULS sensors, this particular limitation can be addressed effectively. The beam angle of 80 GHz radar sensors is merely 30 with 3” process connection which helps in better focusing compared to the traditional 26 GHz sensors where the beam angle is about 100. Hence, one is assured of a reliable and accurate measurement throughout the process. Surface Sludge, Foam, Solids: A Non-issue Wastewater typically sees foam, solids and sludge formation in the treatment water tanks and sumps. Such components may get deposited on the sensor surface interfering with the signal that helps the sensor to accurately measure the levels. However, VEGA’s new 80 GHz based radar instruments operate on a frequency that is 3 times larger than the widely used 26 GHz frequency. This ascribes a dynamic range of 120 dB. The dynamic range makes all the difference for 80 GHz radar sensors. This provides sensors with the necessary sensitivity to detect the smallest signals in Low Dk products, condensation & deposition etc.

Easy display with VEGAMET

VEGAMET controllers allow a large display of measured values making way for easy visualisation. However, controllers can do more than just a visualisation. They can also carry out the additional switching tasks, which is useful in overfill protection, dry-run protection and differential rake control. It also houses various pump control settings such as runtime, fixed sequence, staggered and alternating operations, that offer many more advantages.

Secure supply, Easy installation and Maintenance

Additionally, VEGA radars come with Ex approval, which means they can be used for flammable media.

Easy installation and commissioning of devices is the hallmark of VEGA. Thanks to the VEGA Tools app, anyone can set up, adjust the instruments easily. Bluetooth functionality helps users to keep a safe distance while commissioning as well as taking readings.

This way, VEGA’s Radar is better ultrasonic in the true sense.