Discussion Overview
The discussion revolves around the formation of a substance described as "limescale" in a heater made of Aluminum 5083 used for heating hydrogen peroxide (H2O2) at 150°C for disinfecting plastic bottles. Participants explore potential causes of this deposit, including chemical reactions, water chemistry, and material properties.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant suggests that the presence of hard water may contribute to the formation of deposits, speculating on the dilution of peroxide with water.
- Another participant raises the possibility of corrosion or deposition occurring near junctions due to temperature changes or electrochemical reactions between different materials.
- A different viewpoint proposes that the deposits could be porous alumina or other compounds formed from cations in the water, emphasizing the importance of using demineralized water to prevent such issues.
- Concerns are raised about the solubility of materials being temperature-dependent, questioning the inlet temperature of the peroxide solution.
- One participant hypothesizes that the deposits could be Al2O3, suggesting that its growth is facilitated by the presence of liquid H2O2, which could explain the localized formation at the beginning of the heater.
- Another participant questions the implications of Al2O3 formation, noting that it should lead to pitting or material loss in the aluminum substrate.
- A participant seeks clarification on the nature of the deposits, asking whether they are chalky or hard, which could indicate different underlying causes.
Areas of Agreement / Disagreement
Participants express various hypotheses regarding the nature and cause of the deposits, with no consensus reached on a single explanation. Multiple competing views remain regarding the chemical and physical processes involved.
Contextual Notes
Participants mention factors such as water chemistry, temperature effects, and material interactions, but do not resolve the implications of these factors or their specific contributions to the observed phenomenon.
