Safe and efficient coal handling translates into cost savings and a boosted bottom line for coal companies. Selecting the ideal material-handling system is essential, and Dome Technology is an industry leader not only in storage facilities but also in the optimal handling systems inside and outside the dome.
Handling and reclaim
Selecting the right reclaim and handling systems — not just those moving product within the structure, but loading and reclaim systems too — is key for future financial success. Working with a single team that engineers the storage structure and its material-handling systems results in a seamless, efficient facility.
Coal throughput rate is of utmost importance as it determines the material-handling systems. With both low- and high-volatility coal, “the goal is first-in, first-out. That helps to minimize residence time” and the likelihood of fire and explosion, engineer for Dome Technology Adam Aagard said.
The stacker reclaimer is common for more highly combustible varieties of coal handled by a mechanized system, and the greatest benefit is increased control over where the pile is built and what portion is reclaimed. For instance, if a hot spot is detected, site managers can remove product from a specific area in a hurry.
Another option for some types of coal is a full hopper system. Similar to funnels situated side by side as the “floor” of the facility, this model allows coal to flow through the structure under its own weight rather than by loader. Dome Technology has installed this type of 100 percent live reclaim in projects of various sizes, with the largest being in domes that hold 60,000 metric tons.
Indonesian, PRB or similar types of coal require particular attention to detail when designing and operating to ensure safe storage and handling.
Conveying systems
Conveyors require their own monitoring to ensure proper function, and Dome Technology commonly installs and recommends these systems for coal handling:
>> Infrared cameras check coal temperatures while on the belt to prevent off-spec product from entering the dome.
>> Linear heat cables monitor for fire on the belt and examine bearings for sparks, often detecting a fire traveling along the belt before it reaches the thermal scanner. The system then stops conveyance and alerts facility management of the fire. Workers can either extinguish the fire, or an existing fire-suppression system puts out the flames.
>> Specialized admixtures can be added to the water to aid in quicker cooling and suppression. One option is Hazard Control Technologies’ F-500 Encapsulator Agent that, when proportioned into the water system, extinguishes flames and cools the system faster than water alone could, absorbing as much as 10 times more heat energy than plain water, according to the company.
Dust collecting
Dust collection too requires its own set of precautionary measures, and Dome Technology recommends a wet scrubber that pulls dust through a water system, “and that’s what pulls out the dust rather than a bag, so now the dust is wet and not nearly as combustible,” Aagard said. The system pulls the dust through a duct until it can be removed from the facility or destroyed.
Regardless of the type of dust collection, an automatic system can convey dust away, whether pneumatically or on a belt, to a combustor. Another option is for dust to be collected in a bin or super sack to be hauled away.
In addition to these design measures, proper housekeeping is critical for safe operations at a coal facility. For an in-depth discussion about fire prevention, click here.
This is an excerpt from a Dome Technology article that ran in the June 2016 issue of Dry Cargo International.