Coal bulk handling systems often work as an integrated value chain combining the operations of both fixed and mobile plant elements. Whilst the hardware that constitutes the elements of the system is quite well developed, there are ways in which the entire system can be brought into more unified operational control with relatively low capital investment, this offers many safety and cost saving opportunities. The key to understanding these opportunities is to analytically review and evaluate the value propositions available through the recent advances in mobile plant automation.
What is a Coal Handling System?
Coal Handling systems pervade the entire value chain from the literal coal face to the end users’ final infeed point. These systems include combinations of mobile and fixed plant systems which consist of individual fixed plant elements such as conveyors, trippers and feeders as well as individual mobile plant elements such as stackers, reclaimers, bulldozers, hydraulic excavators, trains, dump trucks and ships. These systems are also interconnected through storage systems incorporating elements including hoppers, silos and stockpiles.
Figure 1: Bulk Handling Systems – Interconnected Elements
The design of these systems involves selecting and deploying individual mobile plant units into fleets and matching them with engineered fixed plant components. This ensures that the required and targeted capacities are met within selected plant availability requirements.
This is a tried and tested approach to bulk solids handling system design. However, modern technology is now at the point where the existing systems that have been designed, built and operated for many years can now be significantly improved with the integration and retrofitting of low cost and high benefit automation systems.
Automation of Mobile Plants
Most modern bulk handling facilities have well designed and automated control systems to operate the fixed plant equipment including items such as conveyors, hoppers and stockpiles. They are usually controlled by PLC (Programmable Logic Controllers) or DCS (Distributed Control Systems) and have a centralised control room from which all operations are controlled and monitored. These systems employ a high level of instrumentation and feed data back to the operators in the control room for their review and action.
In contrast, much of the mobile fleet including trucks, hydraulic excavators and bulldozers working in close co-ordination with the highly automated fixed plant are run through independent control systems usually under the direct supervision of a localised driver/operator. They also often reside in different parts of the operating facility and have varying degrees of alignment with each other even though they are all part of a common coal handling system value chain.
Developments in automation are now allowing new possibilities for the integration of these two historically different styles of operation into a common control system, which has become possible through low cost and off-the-shelf automation options for the mobile fleet. This is made possible through the adoption by mobile plant OEM’s (Original Equipment Manufacturers) and aftermarket systems suppliers of remotely controlled, semi-autonomous and autonomous technologies.
These technologies combine existing equipment hardware such as bulldozers, excavators and trucks with computer based AI (Artificial Intelligence), wireless communication technology and with industrial sensors and actuators to provide a machine that can demonstrate substantial financial and safety benefits for many types of coal bulk solids handling operations.
Safety Drivers for Automation
A common theme with mobile fleet is the removal of the driver or operator from the machine during operations. The technology allows the operator/driver to relocate form the machine into areas such as a common control room located in the operating plant that can be located hundreds of kilometres from the site, a fixed remote control room near the machine or standing behind the machine itself.
Through the lens of the Hierarchy of Controls, elimination of the person from the machine is the best way of reducing the possibilities of harm to the individual hence the method has significant inherent safety benefits.
Other benefits include health and safety related issues where the driver/operator is removed from long term exposure to riding heavy mobile plant on variable grade surfaces as the noise, vibration and emissions exposure can have long term exposure consequences. There are also several other benefits that are equipment type specific and need to be understood and quantified for objective management decision making when considering such systems.
Financial Drivers for Increased Automation
The financial analysis to determine which approach is best suited for the operation at hand consists of both the benefits and costs of adoption and successful deployment and integration of automated mobile plant technologies. In many cases the change management issues are equally as important to the success of any decision to adopt.
The financial benefits normally centre on mobile plant utilisation and productivity improvements, which allow the more efficient use of existing or new assets. Furthermore, significant advantage can be found in the closer integration of the fixed and mobile plant elements that are historically not possible as they have been of different control management platforms. With this type of automation it is possible to concentrate the entire suite of coal handing systems (fixed and mobile) in one control room if appropriate.
Figure 2: Centralisation of Total Bulk Handing Systems Controls
Other financial benefits can be found in the areas of the reallocation of coal tonnage handling between different cost per tonne machine types once the economic factors are weighed against operational considerations. Other areas include workforce redistribution, however, this issue often requires accurate analysis as the answer is not always straightforward or predictable and is highly situation dependent.
How These Developments Can Help your Business
It has been clearly demonstrated that for some coal handling operation types, the automation of the mobile fleet can have significant safety and cost benefits. This is not true for all operations, it is important to assess the potential costs and benefits to determine the true costs and benefits on a case by case basis. It is also important to engage with engineers who understand both the technical and operational aspects of the coal handling value chain and can work with the plant designer, mobile plant OEM’s as well as the plant operations and maintenance teams.
It is important for the engineer undertaking the analysis to be able to understand and unite the various components of the coal handling value chain and produce a realistic analysis to allow the business to make a well informed decision regarding adopting the new technology.
Engenium has significant experience with undertaking such studies and project implementation for clients in the coal industry. Please contact Leon Fabrikanov in our Newcastle office on +61 (0)2 4940 4100, for more information about understanding if these new opportunities are right for your business.
Project Manager, NSW - Engenium Pty Ltd