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Detecting Leaks Along a Coal Slurry Pipeline
Challenge
Coal slurry is the dirty water used to wash coal during mining. After the washing process is complete, the slurry is pumped to a slurry retention pond.
To keep the slurry out of streams and local water supplies, the retention ponds are usually created within valleys between hills. While the slurry is pumped from the mine site over hills into the retention pond, the flow rates are measured at the origination site and at the retention pond. Several additional sensors are positioned at pipeline splices to detect leaks.
Solution
When the topography of a coal mine and its slurry retention pond involves mountains or hills, a clear line of sight between radios is not possible. To allow for a wireless data monitoring solution, a MultiHop radio network was used.
The MultiHop master radio was installed at the mine facility. Of the seven additional MultiHop radios, four radios act as repeaters powered by solar panels or 10 to 30V dc, and three slave MultiHop radios are powered by batteries.
Two 4–20 mA flow sensors are mounted at each end of the pipeline to detect changes in the flow rates. Optical sensors are mounted at all pipeline splices to detect the presence of liquid. When a leak is detected, signals sent from the MultiHop radios back to the control location shut down the pumps.
Because the total length of the pipeline is about two miles, a wireless solution eliminates the need to run power and data cables the length of the pipeline.
Even though there are many environmental obstructions, the MultiHop slave and repeater radios reliably transmit leak detection data back to the master radio.
Featured Products
MultiHop Modbus I/O Data Radios
MultiHop Modbus Data Radios extend the range of Modbus or other serial communication networks. Each radio may be set to act as either a master, repeater or slave. Models are available with built in discrete and analog I/O, which can be accessed using the Modbus protocol.