Why is proper draft significant for the plant operator?

Proper draft is essential for a plant operator because it directly affects the efficiency of combustion within the system. Efficient combustion means that the fuel is burned completely, which maximizes energy output while minimizing waste. When draft is correctly maintained, it ensures that there is enough air supplied to the combustion process, which allows for optimal burning of the fuel.

When combustion is efficient, several benefits arise: it leads to improved thermal efficiency, reduced greenhouse gas emissions, and lower fuel costs due to better fuel usage. Conversely, insufficient draft can result in incomplete combustion, leading to the production of soot, carbon monoxide, and other pollutants, thus harming environmental compliance and operational safety.

The other options, while related to operation and maintenance of the system, do not capture the essential relationship between draft and combustion efficiency as clearly as the correct answer does. Keeping the furnace from overheating, preventing flue gas leaks, and reducing ash production may contribute to a well-functioning system, but they do not address the fundamental importance of draft in achieving an efficient combustion process.