Every year 1.1 billion tons of coal are burned in the U.S., with 90% of that being used for electricity generation.
Several years ago, a University of Illinois professor reported that to produce 109 kWh/year of power, a plant burns 14,000 tons of coal every day. He noted that the coal that goes to a typical coal-fired power plant is crushed to approximately 5 cm in size before it is loaded into the inlet hopper.
As part of its Energy Education information, the University of Calgary reported that:
“Coal plants require enormous amounts of coal. Shockingly: a 1000 MWe coal plant uses 9000 tonnes of coal per day, equivalent to an entire train load (90 cars with 100 tonnes in each!). The amount of coal used during a full year would then require 365 trains, and if each is 3 km long then a single train carrying all of this coal would need to be about 1100 km long; about the same distance as driving from Calgary AB to Victoria BC. If this train were to pass by your house at 40 kilometers per hour, it would take more than a day to pass!”
That is a lot of coal to move and handle. And the interconnected series of steps which takes the coal from the mine to the boiler to deliver reliable electricity to industry and households is aided considerably by a variety of technologies and products.
The coal-fired power plant operations include measuring tonnages, determining coal quality, ensuring personnel safety, and meeting emission regulations. (We’ve discussed many of these steps in our article How to Optimize Coal-Fired Power Plants.)
One of the major steps is the handling of the raw material itself, which involves equipment designed for belt conveyors that move coal and other bulk materials from the mine to the furnace. Here are some of the important technologies utilized in this step of coal raw material handling.
- Belt Scale Systems. Belt conveyor scales help to ensure precise feeding of process materials to maintain product quality. The belt scale system consists of three major elements: the weighing assembly measures the weight of material on the belt, the belt speed sensor and electronic integrator joins the output signals from the scale module and speed sensor to arrive at a rate of material flow and the total material passed over the scale.
- Speed Sensors. As mentioned, conveyor sensors monitor the speed of the belt to help ensure it can carry and move the bulk materials at the correct pace. These sensors can also detect under speed or slippage conditions by checking the rotational velocity of conveyor belts, bucket elevators, and other types of rotating equipment.
- Conveyor protection switches. Conveyor protection switches are important tools in helping to prevent accidents, protect equipment, and reduce unscheduled shutdowns.There are three common types of conveyor protection switches to help ensure the safety of your operations: belt misalignment switch, safety cable pull switch, and a tripper position switch. You can read about them in Stop The Conveyor!… by Using Conveyor Protection Switches.)
- Tramp metal detectors. Tramp metal refers to metallic scrap, including bucket teeth, manganese steel mantles, bore crowns, bar scrap chains, tools, and more, that might break off and land in the raw material. If these pieces of metal are not detected and removed, the expensive crushers, conveyors and other expensive downstream equipment can be damaged.
You can see how all these instruments fit into the basic workflow of a power generation plant. Visit our website and access the interactive app: Coal-fired Power Plant Interactive Workflow.