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Difficulty: MediumDrawing Logical Conclusions

Read the passage below about industrial steam boilers. Which words logically complete the concluding statement about the system's operation?

Answer:In high-pressure steam boilers, dissolved oxygen in the feedwater causes severe pitting corrosion along internal steel pipes. To prevent metal degradation, feedwater is routed through a thermal deaerator where injected steam heats the water to its saturation temperature, driving out dissolved gases before the water reaches the boiler. If the deaerator's steam pressure drops and fails to reach saturation temperature, the concentration of dissolved oxygen entering the boiler will 【increase】, which directly leads to increased 【corrosion】 of the internal piping.

Answer

The concentration of dissolved oxygen entering the boiler will increase (or rise), leading directly to increased corrosion (or pitting/damage) of the internal piping.
The passage explains that heating water to saturation temperature removes dissolved oxygen, which otherwise causes pitting corrosion. If the deaerator fails to reach that temperature, oxygen is not driven out, causing its concentration to rise and consequently escalating pipe corrosion.

Step-by-Step Solution

1
Identify the primary mechanism of gas removal and protection described in the text.
The text states that steam heating water to its saturation temperature in the deaerator drives out dissolved oxygen, which prevents corrosion.
Understanding the baseline operational cause-and-effect relationship is necessary before analyzing a system failure.
2
Determine the direct consequence when steam pressure drops below saturation requirements.
Without reaching saturation temperature, the deaerator cannot drive out dissolved gases, meaning dissolved oxygen remains in the water and increases in concentration entering the boiler.
Deducing the failure state requires reversing the protective effect when the prerequisite condition is not met.
3
Synthesize the final outcome on the boiler piping.
Higher dissolved oxygen levels entering the boiler directly accelerate metal degradation, leading to increased pitting corrosion.
Connecting the increased oxygen level back to the initial premise establishes the logically complete conclusion.

Key Concept

Drawing logical deductions from technical cause-and-effect relationships
Estimated Time:1m 0s
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Topics

Drawing Logical Conclusions

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