How is the flow of natural draft controlled?

The flow of natural draft is typically controlled by dampers that are operated by automatic controls. This method allows for precise regulation of air flow in response to changing conditions within the system. Dampers can be adjusted to either open or close, allowing hot gases to rise and exit the system while simultaneously regulating the amount of fresh air entering. This automatic adjustment is crucial to maintaining optimal operating conditions and efficiency.

While manual switches could theoretically control the draft, they lack the responsiveness and precision needed for effective operation in a dynamic environment. Gravity does play a role in the natural draft process, as it helps move gases upwards, but it cannot be adjusted or controlled in a manner that achieves the needed regulation for operational efficiency. Maintaining a constant temperature is important for certain operations, but it does not directly control the flow of natural draft; instead, it can be a byproduct of how well the draft is managed through the use of dampers.

Therefore, dampers operated by automatic controls best represent the most effective and efficient method for controlling the flow of natural draft.