What is the temperature at which a non-azeotropic blend first begins to evaporate called?

The temperature at which a non-azeotropic blend first begins to evaporate is known as the Bubble Point. This term describes the point at which the first bubble of vapor forms when heating a liquid mixture. When you reach the Bubble Point, the liquid starts to turn into vapor, which is a critical concept in understanding phase changes in refrigerants and mixtures.

In the context of non-azeotropic blends, different components evaporate at different temperatures. Therefore, the Bubble Point is specific to the composition of the mixture and indicates the temperature where the first vapor phase appears. This distinction is important for technicians working with refrigerants, as it helps in the effective management of refrigerant mixtures in various applications.

Other terms such as Melting Point, Boiling Point, and Critical Point describe different phenomena or characteristics of substances. The Boiling Point refers to the temperature at which the entire liquid phase turns into vapor, not just the first part. The Melting Point pertains to the temperature at which a solid becomes a liquid, while the Critical Point is defined as the conditions at which the phase boundaries between liquid and vapor cease to exist. Understanding the unique definition of the Bubble Point is essential for effectively working with refrigerants and ensuring proper handling and management in HVAC systems.