In recent years, there has been growing awareness when considering the correct transfer chute during the design phase of a plant. This is, in part, due to current trends that have resulted in a new approach to design methodologies.
MARK BALLER, MD of Weba Chute Systems, discusses the topic with GERARD PETER and points out the numerous benefits in ensuring that the correct transfer chute is identified during the plant design process.
In the past, Baller has raised concerns that transfer chute systems were considered an afterthought in plant design even though it is a vital piece of equipment in any material handling process.
“For many years, the perception existed that there was no design thought process that went into manufacturing a chute, rather it was just something that a boilermaker knocked together in a yard,” he states. Thankfully, this perception has slowly changed over the years.
This change, says Baller, is a result of a distinct shift in mentality over the past 40 years when it comes to frontend engineering and design (FEED). “In the past, from a planning point of view, designers tried to make everything as compact as possible, to make it as cheap as possible. This was a nightmare for clients when it came to maintenance and operations.
“Also, the design of a plant only considered the structure and didn’t consider other aspects such as water pipes and electric cables that also need to be installed. Because everything was so compact, it was difficult to access areas to do maintenance or change parts.”
Fast track four decades and this has changed. Baller explains that today clients and engineers have a far better grasp of the challenges that were previously experienced. As a result, they are applying the lessons learnt and using new technologies in the design process to overcome obstacles that could be faced further down in the project pipeline – way before commission and operation.
Baller adds that three aspects must be considered when designing a plant: profitability, safety, and the environment. “A company can invest hundreds of millions of rands in their plant’s infrastructure, so it is very important to ensure that the plant is profitable,” he says.
He adds that there is a lot more emphasis placed on safety during a plant design process. “Designers now look at ease of maintenance and the challenges of working in confined spaces by making areas more accessible. If you can achieve this, you minimise the dangers involved in operating and maintaining equipment.”
There is also a substantial emphasis on protecting the environment and reducing the impact of mining operations on nearby communities. Currently, FEED methodologies consider, among others, gas and dust emissions, water usage and dealing with wastewater.
Selecting the right shoot is paramount
Since it was founded in 1984, Weba Chute Systems has an ongoing commitment to educate the industry about why choosing the correct transfer chute not only benefits safety and the environment, but also provides financial benefits when it comes to maintenance, performance, and longevity of its equipment.
During the early 1990s, the company conducted a comprehensive study into the negative and cost-incurring aspects of conventional chute design and set out to create a transfer chute that would eliminate these problems. This resulted in the development of the Weba Transfer Chute System — a streamlined, scientific approach to the dynamics of bulk material handling at transfer points. Today, the company has installed more than 5 000 transfer chutes in more than 50 countries.
Because of this experience and expertise, both EPCMs and clients now engage with the company during the design phase of a plant. “Our clients recognise what Weba Chute Systems brings to the table and this is why they get us involved incredibly early in a project. At this stage, we can assist them with the positioning of a chute and equipment such as pulleys as well as the configuration of transfer points to ensure optimal performance,” Baller explains.
Such consultations not only result in ensuring the correct transfer chute is selected for a mining operation, but also have other financial benefits for clients. A case in point: dust reduction in transfer chutes is of paramount importance. In many instances, companies invest substantially in peripheral equipment to deal with this issue.
However, this is not always necessary, says Baller. “You cannot transfer material without making dust, but the amount of dust you make depends on the impact, velocity, and the material within the transfer chute. By designing a chute properly, you can reduce dust by up to 80%. In this way, instead of putting a plaster on it, you are addressing the wound. As a result, the amount you spend on a dust suppression system is far less.”
Selecting the correct transfer chute at an early stage has already reaped positive results for Weba Chute System’s clients. “Already, we’ve managed to achieve the emissions targets without any peripheral equipment. This is because we ensure that we provide clients with a chute that performs better, is maintenance-friendly and produces less harmful emissions,” adds Baller.
Ensuring that the correct transfer chute is installed, all starts at the design stage. To that end, Weba Chute Systems has invested heavily in discrete element modelling (DEM), a technology that uses numerical methods to model interaction between individual particles and boundaries to predict bulk solids behaviour. However, while many companies use DEM to design their transfer chutes, Weba Chute Systems has a different approach.
“We do our mathematical calculations and apply our extensive knowledge at the design phase. We only run the DM software after the design as a verification tool to check the design. In this way, we ensure that a client can visualise the performance of our transfer chutes and is confident about the performance we have outlaid for our equipment,” Baller says.
Getting involved in the early design stage is already reaping dividends for mining companies. “It is not only good for us but also for EPCMs and projects companies. At the end of the day, client satisfaction is what we are all striving for, and we want to ensure that they are satisfied with our transfer chutes’ performance. That is why our clients come back to us,” Baller concludes.