The mixture of which two components is transferred to the deaerator from the surge tank?

The transfer of condensate and raw makeup water to the deaerator from the surge tank is crucial for effective boiler operation. This choice is correct because the deaerator's primary function is to remove dissolved gases, particularly oxygen and carbon dioxide, from the water used in a steam system.

The condensate, which is water formed from steam after it releases its heat energy, is already at a relatively low temperature and contains less dissolved oxygen compared to raw makeup water. Raw makeup water is typically sourced from a reservoir and can contain higher levels of dissolved gases. When these two components are combined in the deaerator, it allows for the efficient removal of these gases before the water enters the boiler.

By ensuring that the water fed into the boiler is free from oxygen and carbon dioxide, the risk of corrosion and scaling within the boiler is significantly reduced, thus enhancing efficiency and prolonged equipment life. The other choices involve components that do not fulfill the specific purpose of maintaining water quality for steam generation; thus, they are not suitable for the operation of a deaerator.