Turning wastewater into a resource

Managing wastewater effectively poses significant challenges, particularly in separating solids from clean water during treatment processes. This task can be complicated and inefficient, often leading to operational delays and potential equipment failure. Here’s how Technidrive partnered with a leading American company specialising in washing equipment to implement an innovative dual-gearbox system that enhances sludge management and optimises overall water treatment efficiency.

There is a critical need to reframe the narrative surrounding wastewater, particularly in low- and middle-income countries where resource recovery practices are still emerging. During a recent International Water Association (IWA) webinar, attended by wastewater utility managers, water-energy policy makers and more, the sentiment was clear. “Stop using words with waste. Change it to resources,” commented one participant, emphasising the potential value that lies within wastewater. This shift in perception is essential for encouraging sustainable practices and investments in wastewater treatment.

Wastewater treatment systems face a range of significant challenges, particularly in thickening and sludge management processes. One of the common issues in thickener applications is correctly identifying the build-up of sludge at the bottom of thickener tanks, de sludging too late can impact operational efficiency and lead to equipment failures if not properly monitored and managed. Over-sludging can also reduce the effectiveness of water recovery, increase maintenance costs and disrupt the entire treatment process.

On the other hand, premature desludging can waste resources and energy, making it vital for companies to adopt precise monitoring solutions. Additionally, environmental concerns, such as the risk of oil leaks into water systems, further complicate these processes. The need for reliable, efficient and environmentally friendly technologies has never been more urgent as industries strive to meet rising regulatory standards and sustainability goals.

The potential for resource recovery

A prominent American company, specialising in washing equipment and water treatment solutions across various industries, faced considerable challenges with its thickener systems. The systems are essential for separating clean water from solids during the water treatment process.

The thickener operates by introducing dirty water into a large tank, where a chemical solution promotes the separation of solids from the water. A slow-moving blade within the tank pushes the accumulated solids or sludge to the bottom, allowing clean water to overflow from the top. The primary challenge for the company was accurately determining the optimal timing for desludging, as pumping too early could lead to the loss of clean water, while delaying the process could result in excessive pressure on the system, risking inefficiencies and potential equipment failure.

Innovative solutions for thickener systems

To address these challenges, the company sought an innovative solution that could improve the accuracy of sludge detection without relying on conventional methods that proved inconsistent. They collaborated with Technidrive to develop a dual-gearbox system equipped with a load cell to measure torque directly related to sludge thickness. This approach allowed for precise monitoring of sludge buildup and timely desludging, optimising the thickening process.

Technidrive’s innovative first-to-market solution utilises two planetary gearboxes to achieve significant torque magnification, enabling precise monitoring of the torque at the drive’s input, which directly correlates to the thickness of the sludge at the bottom of the thickener tank. The advancement centres around a new load cell design that significantly enhances the accuracy of torque sensing in thickeners, crucial for effective sludge management.

“The load cell serves as a vital component of the gearbox system, providing precise measurements of the torque exerted,” explained David Strain technical director at Technidrive. “Previous methods of torque sensing, such as monitoring the motor’s current or attempting to gauge sludge levels through the water, were either inaccurate or inconsistent. The new system integrates advanced torque sensing capabilities, eliminating these issues by delivering reliable data on sludge thickness, enabling operators to optimise the cleaning process.

“The successful implementation of this technology not only resolved the company’s immediate operational issues but also positioned it to enhance its water treatment solutions across various sectors, ultimately aiming to improve overall efficiency in an industry facing increasing infrastructure demands.”

By employing a load cell positioned between the gearboxes, Technidrive provides a reliable and accurate means of detecting sludge buildup, allowing operators to determine the optimal timing for desludging. This innovation minimises the risk of premature or delayed desludging, thus enhancing operational efficiency and preventing undue pressure on the system.

Features of the new gearbox

The gearbox design boasts several innovative features, including two separate gearboxes equipped with expansion tanks. These tanks allow for easy monitoring of oil levels, crucial for preventing leaks that could contaminate clean water sources. Integrated glass tubes alongside the tanks provide a clear view of the oil levels, while automated oil level monitoring switches alert operators when oil levels drop below safe thresholds, ensuring immediate attention to potential leaks.

For this project, a WIMES Spec motor, specifically the W22 model from WEG, was selected. A WIMES Spec motor is an electric motor designed according to the Water Industry Mechanical and Electrical Specification (WIMES) standards, ensuring compatibility, performance and reliability in water and wastewater applications.

Renowned for its durability and performance, the W22 motor is backed by a comprehensive build specification and a five-year warranty. The motor’s corrosion-resistant paint finish ensures maximum robustness and an extended service life. Designed for low energy consumption, it significantly reduces operational costs throughout its lifespan. Additionally, factory-fitted condition monitoring features, including PTC thermistors and vibration monitoring provisions, enhance its reliability and performance.

The gearbox selected for this project is a 300 Series heavy-duty planetary gear unit from Bonfiglioli. This gear unit is designed for heavy-duty applications, ensuring robust performance even in harsh environments. With back-to-back taper roller bearings on the output shaft, the 300M Series delivers high flexibility and can be customised to meet a wide range of application requirements. This modular design allows it to operate without unwanted downtime, further enhancing efficiency in water treatment processes.

Sustainability and industry impact

This project aligns with broader sustainability goals in the quarrying industry. Over the last decade, washing processes have become increasingly important as companies seek to recycle materials previously designated as waste. By using water to clean aggregates, operators can minimise reliance on virgin materials, thus reducing their environmental footprint.

As quarry operators shift towards washing waste materials and recycled aggregates, effective sludge management becomes essential. Traditionally, dirty water from these processes would be funneled into settling ponds, which are inefficient and space-consuming. The new gearbox system allows for more effective water treatment, ensuring that waste materials are handled efficiently and sustainably.

Future prospects

It’s therefore no surprise that this innovation in gearbox technology is already making waves in the water treatment industry, particularly for applications involving quarrying. Customer feedback has been overwhelmingly positive, noting the improved accuracy of the torque sensing and the overall effectiveness of the system. Given the successful implementation of this technology, there are expectations for repeated orders and potential applications in other sectors of the water industry.

With increasing focus on water infrastructure and sustainability, this innovative gearbox system not only offers immediate benefits to quarry operators but also positions itself as a pivotal solution for broader water treatment challenges in the future.