MCA talks to Stephan Bergh of Howden, a Chart Industries Company, about Ventsim CONTROL, the company’s ventilation optimisation solution, which offers five levels of control for on-demand mine ventilation, ranging from manual remote control to advanced algorithms. Already in widespread use, energy consumption for ventilation systems can be reduced by between 10 and 70%.
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Mine ventilation and cooling systems typically comprise between 40 and 50% of a mine's total energy consumption.
Howden has long been known in South Africa as an OEM of ventilation fans, cooling and engineered solutions for underground mining, tunnels and wastewater facilities, as well as solutions for power industries. “Howden was founded by James Howden in Scotland in 1854 and quickly became an established designer of rotary blowers and compressors,” begins Stephan Bergh, Mining Lead for Howden Africa, Middle East and India, adding that the company has donned many caps to support different mission critical processes across multiple industries over its 170-years of history.
“In March of 2023, Howden was acquired by Chart Industries, the US-based molecule handling specialist and world leader in cryogenics, liquefied natural gas and hydrogen amongst others. This is a good fit for Howden, which has always been an air and gas handling solutions provider.
The combination of the Chart and Howden products and solutions is very exciting, and we look forward to supporting our customers in new, and more comprehensive ways ,” he tells MCA.
“As an OEM, we traditionally supported our customers at ‘the request for proposal stage’ with regards to mine cooling or fan applications. Howden wanted to get involved earlier in the value chain to support our customers more comprehensively and to build mutually beneficial relationships.
This led to the establishment of a consulting arm that offers specialised engineering services to support mines from the inception stage all the way to the end of the asset’s life,” he says.
The Ventsim Family of Products and Solutions
At the core of Howden’s offering for underground mine developers and operators is Howden’s Ventsim software solution, which is a critical component Howden’s total mine ventilation solution (TMVS).
“Ventsim is split into two distinct packages; Ventsim DESIGN and Ventsim CONTROL. Ventsim DESIGN is a complete and integrated mine and tunnel ventilation software package for the design, simulation and testing of ventilation circuits. It affords the user the opportunity to perform detailed scenario planning and analysis of different factors including airflow, pressure, heat, gases, power consumption, radon, fire and others, and to design a system that is robust and efficient to support customers on their journey to ZERO HARM and ESG excellence,” Bergh continues.
Ventsim CONTROL is an intelligent, customisable underground Ventilation Optimisation/Ventilation on Demand (VOD) software solution that communicates with hardware devices, allowing remote monitoring, control, automation and optimisation of airflow, heating, and cooling.
“As for specialised consulting services, our team of engineers, leveraging the power of our solutions, global footprint and collective experience, are able to design robust, and efficient ventilation and mine cooling solutions to support our customers’ operations across the life of the asset. Truly an all-encompassing single point of contact solution,” notes Stephan Bergh.
Ventilation optimisation
Mine ventilation and cooling systems typically comprise between 40 and 50% of a mine's total energy consumption. “The rise in energy cost and availability of energy, paired with ESG/carbon footprint reduction commitments and more stringent health and safety standards, are forcing engineers and mine planners to design more efficient operations. Fan and compressor motors often have to run continuously, which leaves room for optimisation: based on the level of activity as well as changes in conditions underground,” he argues.
Mine ventilation and cooling systems are critical from a health and safety point of view. Fundamentally, they are responsible for providing oxygen, controlling airborne pollutants, diluting gases, and controlling temperatures underground. Each case must be thoroughly investigated to establish the most optimal solution and optimisation strategy, with health and safety remaining top of mind, while also considering the financial metrics and economic impacts.
Solutions might include fans only, or a combination of fans and cooling equipment to mitigate sub-standard environments and to minimise exposure to stressors at permissible levels.
“Apart from the control of fans, doors and regulators, Ventsim CONTROL further allows mines to optimise their cooling installations. The cooling plant duties can be modulated based on changes in ambient conditions and the level of activity underground. We are cognisant of the fact that reducing the duty of the cooling plant could have knock on effects downstream, such as a build-up of residual heat in the workings.
“In our pursuit of optimising energy usage, we are currently in the process of harnessing the power of machine learning and predictive modelling to develop a new Temperature Prediction Controller designed to determine the optimal timing for initiating cooling or heating processes in specific areas. Our aim is to avoid wasteful energy consumption that often results from starting heating or cooling processes too early, ensuring that the desired temperatures are achieved exactly when activities are set to begin,” Bergh explains.This is where Ventsim CONTROL comes in: Historically, he continues, mine ventilation solutions were designed with the end view in mind, and mines were ventilated at full capacity for the duration of their life, irrespective of the conditions or level of activity underground. But tonnage profiles change and their associated varying levels of activity allow room for optimisation. Thinking short term – every hour of the day or day of the week – there are travelling and maintenance windows, pre- and post-blast events, etc. Each of these are associated with varying levels of activity and running ventilation and mine cooling installations at peak capacity on a continual basis will likely lead to energy wastage.”
Ventsim CONTROL is firstly focused on improving workplace conditions underground. Automated control of these devices eliminates manual intervention, ensuring a seamless and safe operation. Monitoring and control of contaminant gases ensures compliance with regulations. “In addition to the health and safety benefits and energy savings, gas dispersal can be accelerated following blasts to reduce production downtime,” he explains.
Five levels of Ventsim CONTROL
To cater to various levels of sophistication at different mines, Howden has incorporated five levels of control into its Ventsim CONTROL solution.
Level 1 is manual remote control. This enables the mine to remotely manipulate ventilation devices. This could be switching fans on or off, speeding them up or down, and/or opening and closing doors and regulators.
“Level 2 is where we apply programmed automated scheduling for events. For example, if the mine has a maintenance window between 6:00 am and 8:00 am every Tuesday and Thursday with consistently limited mining activity, the surface fan speed might be reduced from 100% to 90% during those periods and auxiliary underground fans would be switched off in areas where it is safe to do so,” Bergh says.
Level 3 involves the installation of flow, gas and temperature sensors to collect and monitor key underground conditions. The software then computes and calculates the air and cooling demand required to comply with and maintain acceptable standards underground. The Ventsim CONTROL software in turn communicates with hardware underground to ensure ventilation devices react accordingly to support conducive conditions.
Level 4 adds tracking and tagging integration for underground equipment. “A mine can then track the movement and activity of its vehicle fleet to see if and where they are operating. Ventsim CONTROL collects that data and responds by extracting pollutants and heat based on the location and status of the equipment.
And in Level 5, the highest level of integration, as much data as possible is collected from each area of the mine. By using carefully designed algorithms, Ventsim CONTROL continuously looks to reduce the system resistance in the mine. This enables fans to run at a lower pressure, leading to reduced power consumption brought on by a reduction in fan speed. “The cubed relationship between fan speed and power leads to significant energy savings with small reductions in speed. This is how we have supported our customers to achieve their energy savings commitments with some mines reducing ventilation related power consumption by up to 70%,” he notes. “The primary goal of Ventsim CONTROL is not to save power, though. That is a by-product. The goal is to guarantee safe and healthy working conditions by coupling real time monitoring with real time action.
“If a mine can see sub-standards occurring in real time and has the ability to mitigate the event through either manual or autonomous intervention in real time, we would have made enormous strides on our collective journey to ZERO HARM,” Stephan Bergh concludes.
www.chartindustries.com/Businesses-Brands/Howden
