Recovered refrigerant may contain which of the following impurities?
a. Ammonia, carbon dioxide, and methyl chloride
b. Sodium chloride, potassium nitrate, and silicone oil
c. Sulphur dioxide and methane
d. Acids, moisture, and oil
The Correct Answer and Explanation is :
The correct answer is d. Acids, moisture, and oil.
When refrigerants are recovered from refrigeration systems, they may contain various impurities that can degrade their performance or damage equipment. Let’s break down why “acids, moisture, and oil” are the most common contaminants:
1. Moisture:
Moisture can enter a refrigeration system through leaks or during service procedures. If left unchecked, water can react with the refrigerant, leading to the formation of acids. Moreover, moisture can freeze within the system, forming ice that could block valves or capillary tubes, leading to inefficient operation or system failure.
2. Acids:
Acids are typically formed when refrigerants break down due to exposure to high temperatures or moisture. These acids can corrode internal components of the refrigeration system, including metal parts and seals, leading to leaks, mechanical failure, and reduced efficiency. Acid formation is especially common in systems where the lubricant or refrigerant has decomposed due to extreme operating conditions or contaminants.
3. Oil:
In many refrigeration systems, oil is used to lubricate the compressor. However, during the recovery process, oil can mix with the refrigerant. This can be problematic because oil can alter the thermodynamic properties of the refrigerant, decreasing the system’s efficiency. Furthermore, oil contamination can lead to clogged filters and other operational issues.
Why not the other options?
- a. Ammonia, carbon dioxide, and methyl chloride: These are refrigerants themselves, not typical contaminants.
- b. Sodium chloride, potassium nitrate, and silicone oil: These chemicals are not commonly found in recovered refrigerants.
- c. Sulphur dioxide and methane: While these gases can be harmful, they are not typical contaminants of recovered refrigerant in most systems.
Therefore, the most likely impurities in recovered refrigerant are acids, moisture, and oil.