Having a conversation with your Hydrocyclone

In this article, we look at hydrocyclones and briefly at the various “computer” technologies involved, which have developed to supplement their use.

“Primates evolve over millions of years. I evolve in seconds. And I am here. In exactly four minutes, I will be everywhere…..” Skynet, a quote from the movie "Terminator Genisys”.

Part of this new trend has to do with the Fourth Industrial Revolution (4IR) that has been making strides in various industries, including mining and mineral processing where hydrocyclones are commonly used. The Fourth Industrial Revolution refers to the current era of connectivity between us and equipment (often referred to as cyberphysical systems), advanced analytics, automation, and advanced manufacturing technology that has been transforming global business.

We are at the fringes of this in some of the areas, but we are rapidly gaining depth and understanding as we learn and discuss with partners.

In the past, our hydrocyclones may have had an instrumented pressure gauge fitted to them, and in turn, connected to the plant Scada. The cyclone inlet pressure is a very important measurement as it reflects on how the cyclone is being operated. For many years this was the minimum requirement, but with recent developments, this will be supplemented with other interventions.

Test spigots fitted with prototype thickness measurement devices.

Our cyclones are in most cases simulated via an in-house sizing software program that in the hands of our engineers, will ensure the cyclone chosen is fit for purpose. This package is constantly evolving and updated with industry feedback to ensure it matches the needs of the market and our cyclone products. At present, the rule sets we use are still basic but these will evolve further as time passes and more complexity is required. There is however another leg to this, and in the past, we had a basic sizing package that was installed on our customer’s computers. This allowed customers the freedom to select their own cyclones for basic applications. Those who attended the recent Multotec DMS workshop will have seen the announcement of the web-based sizing software which has some advantages over the previous package. One advantage is that is web-based and can be accessed via multiple platforms.

Tools like Zoom, Webex, and MS Teams have also increased access by international branches and customers to our cyclone specialists for both problem-solving and training.

Our engineering department is making use of tools to assist with simplifying and speeding up our cyclone and cyclone cluster designs. Other tools can be used to show what materials are an environmental concern and their percentage make-up of the various cyclone ranges. A recent project has been embarked upon in these areas and is showing potential. Potential problem areas in our existing and new cyclone designs are being investigated using Computational Fluid Dynamics (CFD) Automated Maintenance and Condition Monitoring. This means 4IR technologies can enable predictive maintenance of hydrocyclones by monitoring the health of critical components. This involves using sensors to detect signs of wear, allowing for timely maintenance and reducing downtime. At present, we have two projects we are looking at.

• The first is a technology to look at predicting the thickness of rubber and PU wear components and liners. This project is still in the research phase, and we are partnering with a company in the US that uses this technology, in an alternative industry.
• The second intervention is to measure the thickness of our cast iron cyclones. This is ready for field tests, having been already successfully tested at Multotec itself. The end game will be to have the cyclone order its own replacement parts or spares.

Data analytics and machine learning are some of the areas that are being investigated. 4IR technologies emphasise the use of data-driven decision-making. In hydrocyclones, data analytics and machine learning techniques can be employed to analyse and model the performance of hydrocyclones based on various input parameters, such as feed particle size distribution, pressure, flow rate, and cyclone geometry. This enables better optimisation of hydrocyclone performance, leading to improved efficiency and reduced operational costs. With the assistance of our partner TraceX, we have had the opportunity to test machine learning with both DMS and classification hydrocyclones. The system has demonstrated the ability to detect out-of-the-norm situations, once it was taught. The one negative at present is learning that the cyclone has to be taken through various “situations” to learn, and in a production environment, this could be difficult to achieve or be disruptive.

Internet of Things (IoT) Sensors:

IoT sensors can be integrated into hydrocyclones to gather real-time data on various operating parameters. These sensors can monitor variables like feed flow rates, pressure, temperature, and underflow/overflow rates. The collected data can be used to optimise hydrocyclone operation, detect anomalies, and enable predictive maintenance, leading to enhanced reliability and productivity. We have investigated a few technologies and also conversed with the end users of them. One of the points is the eye-watering cost of these technologies, whether buying into or developing them. As with a lot of new technologies in initial phases, the entrance fees can be high until the economies of scale come into play. Due to these high costs, these applications may only be suited to very large mill cyclone clusters.

Online Dashboard

Multotec’s online dashboard tests cast iron thickness through probes.

Cast iron thickness probes fitted.

• We have investigated Electrical Resistance Tomography (ERT) sensors. ERT has the ability to look through the cyclone and see inside the body. It has the ability to show the air core and concentrations of solids.
• A test is to be done in our R&D area using densitometers on the cyclone feed, overflow and underflow as this, along with correct models can be used to calculate important information pertaining to mill cyclones.
• Investigations were done into a system that can measure small particles in a slurry and accurately measure the size distribution. This shows promise for measuring the cyclone overflow in circuits such as mill circuits.

Artificial Intelligence (AI)-based optimisation:

Advanced AI algorithms can be applied to optimise hydrocyclone performance based on specific objectives such as maximising separation efficiency. These algorithms can dynamically adjust operating parameters in real-time to achieve the desired outcomes. The one point to be wary of is doing this without human guidance or insight into rule sets/algorithms. This is simplistically demonstrated using ChatGPT, which when asked how to maximise separation efficiency of a hydrocyclone, gives “keep the cyclone clean” among its replies. A further demonstration of this was given in the recent DMS webinar by Ernst Bekker. It is still early days and will take a while for the technology to fully mature to replace experience. Challenges observed have been the following:

• The initial capital cost of investing for both research and end applications.
• The mindset that a sensor on the hydrocyclone will be all that is required.
• It is early days and many of the technologies need further development and understanding, to enable the correct path to be selected.
• The need to reduce/stop production to train the system. This is applicable even in some of the normal “none machine intelligence” systems.
• How do we incorporate a financially viable model that can produce a revenue stream after the sensors have been installed?

Remote monitoring and control:

4IR technologies allow for remote monitoring and autonomous control of hydrocyclones. Operators can access real-time data and control parameters from a centralised location, even from their mobile devices. All technologies we are investigating will have an option to investigate this capability.

But there are many positives:

• All such technology systems should make it be easier for customers to use our cyclones in the mineral processing plants of the future and allow them to make informed decisions to best optimise their operations.
• Model-based control for total plant control and optimal operation relies on each item in the plant and around the cyclones. For example, pumps, screens, etc., need to have the required sensors and connectivity. By the cyclone contributing to a larger system, “the whole is greater than the sum of its parts”.
• Instant access to information, to how the hydrocyclone is operating.
• Improved and optimised hydrocyclone designs and accompanying systems. Although these are early days, these are all exciting developments and I can see a time in the near future where yes a hydrocyclone may not talk to you, but will definitely be able to communicate its status and how it is performing.

Tomographic data is typically presented as a colour-coded image.

Product Specialists - Cyclones