Our Water Cart Auto-Fill System

AUTOMATING & INCREASING WATER CART EFFICIENCY

Many mining operations are yet to automate the filling process of their water carts at in-pit fill points. Typically, water carts use hand held remotes to open and close the valve at the fill point manually. The manual remotes do not provide any over-fill protection as they rely on the operator to hit the close button once they notice the tank overflowing, the time to close once command is given for the valves is approx. 30-45 seconds while the tank is already overflowing. For large water carts, the average water lost per fill without any form of automated system is anywhere between 5,000-15,000L.

We wanted to address this problem with a workable solution to automate and optimise the filling process of water carts. Our system constantly measures the level in the water cart tank & displays a live visual indication to the operator, when re-filling at the in-pit fill points the system uses the live tank level data and automatically sends the close signal to the fill point valve at a level that allows the valve to close and all remaining water in the pipe to empty, leaving the water truck 100% full without overflowing any water. The water cart can be brought to the fill point and any level (0%, 30%, 70%) and the system will automatically adjust to these levels without affecting operation.

The starting of the filling process is achieved by a singe press of the start button by the operator once he is comfortable he is positioned correctly beneath the discharge pipe, there is built-in redundancy in the system that allows for a manual close signal to be sent by the operator in the unlikely event of failure of the automatic system.

Our objective was to design a cost-effective system to eliminate overfilling of water carts at fill points & improve operational efficiency by providing operators with a visual indication of tank level to aid route planning.

The system has been designed using standard instrumentation components & simple programming to aid maintainability and avoid issues inherent with proprietary products.

The system consists of a display screen in the cab in view of the operator to display a live feed of current tank level, control module outside of the cab and level measurement device either on top or beneath the tank.

The display screen allows the operator understand when to head back to the fill point, once aligned beneath the discharge pipe the “start” button is pressed to begin the filling process. Once the tank level reaches a pre-determined level the system automatically sends a signal to the fill point to close the valve and stop the filling process, by the time the valve closes and all water leaves the pipe the truck is left filled to an optimum level without overflow.

Production Benefits

• Increase watercart efficiency by providing operator with visual indication of tank level
• Allow operators to assess when to return to fill point to reduce empty truck operating time
• Eliminates truck overfilling time and wasted water during the filling process
• On board water capacity known for emergency fire-fighting situations

Maintenance Benefits

• Reduce maintenance cost from corrosion to components as a result of overfilling raw water onto the truck
• Simple modular component changeout and transferable to other machines