A chain grate stoker can successfully burn coal with _____.

A chain grate stoker is specifically designed to efficiently burn solid fuels, particularly coal. The correct answer reflects that chain grate stokers are particularly effective with coal that has a high volatile content. High volatile content means that the coal releases a significant amount of gases when it is heated, which is beneficial for combustion. This gas release can enhance the ignition process and contribute to a more efficient and complete burn due to the ample supply of combustible gases.

Coal with high volatile content tends to ignite more readily and can provide a higher flame temperature, making it easier for chain grate stokers to manage the combustion process. These types of stokers are well-suited for handling the ash produced and can accommodate the necessary air supply to properly combust the volatile gases released.

In contrast, lower volatile content coals do not produce as many combustible gases and require higher temperatures and more precise control for efficient burning, which can be less compatible with the operation of a chain grate stoker. Thus, while it may be possible to burn coal with lower volatile content in some contexts, the design and efficacy of a chain grate stoker align best with coal that has a high volatile content, ensuring optimal combustion performance and operational efficiency.