1. CAVITATION
- Cavitation is the formation of vapour cavities in a liquid.
i.e. small liquid- free zones ("bubbles" or "voids") that are the consequence of forces acting upon the liquid due to pressure variation in flow.
- In many cases, an undesirable occurrence. In ID fan such as fan blade, cavitation causes a great deal of noise, damage to components, vibration, and a loss of efficiency.
2. IMPACT
- Due to cavitation high impact force produced bubbles on blade surface in a liquid rapidly collapses, producing a shock wave.
- Due to that action impact force more then stress - strain level of the material which causes damage of blades.
3. EROSION
- Erosion corrosion is a degradation of blades surface due to mechanical action, often by impinging liquid, abrasion by a slurry, particles suspended in fast flowing liquid or gas, bubbles or droplets, cavitation, etc.
4. CORROSION
- Corrosion is a natural process, which converts a refined metal to a more chemically-stable form, such as it's oxide, hydroxide, or sulfide. It is the gradual destruction of materials (usually metals) by chemical and/or electrochemical reaction with their environment.
5. FRICTION
- Friction is the force resisting the relative motion of solid surface, fluid layers, and material elements sliding against each other.
- When surfaces of beads and casting of ID fan move relative to each other, the friction between the two surfaces converts kinetic energy into thermal energy (that is, it converts work to heat) which increase the temperature of blades surface.
6. TEMPERATURE
- High - temperature corrosion is chemical deterioration of metal as a result of heating. This non- galvanic form of corrosion can occur when a metal is subjected to a hot atmosphere containg oxygen, sulfur, or other compounds capable of oxidizing of the material concerned.
- For example, material used in ID fan blades have to resist sustained period at high temperature in which they may be exposed to an atmosphere containg potentially highly corrosive product of combustion.
- Cavitation is the formation of vapour cavities in a liquid.
i.e. small liquid- free zones ("bubbles" or "voids") that are the consequence of forces acting upon the liquid due to pressure variation in flow.
- In many cases, an undesirable occurrence. In ID fan such as fan blade, cavitation causes a great deal of noise, damage to components, vibration, and a loss of efficiency.
2. IMPACT
- Due to cavitation high impact force produced bubbles on blade surface in a liquid rapidly collapses, producing a shock wave.
- Due to that action impact force more then stress - strain level of the material which causes damage of blades.
3. EROSION
- Erosion corrosion is a degradation of blades surface due to mechanical action, often by impinging liquid, abrasion by a slurry, particles suspended in fast flowing liquid or gas, bubbles or droplets, cavitation, etc.
4. CORROSION
- Corrosion is a natural process, which converts a refined metal to a more chemically-stable form, such as it's oxide, hydroxide, or sulfide. It is the gradual destruction of materials (usually metals) by chemical and/or electrochemical reaction with their environment.
5. FRICTION
- Friction is the force resisting the relative motion of solid surface, fluid layers, and material elements sliding against each other.
- When surfaces of beads and casting of ID fan move relative to each other, the friction between the two surfaces converts kinetic energy into thermal energy (that is, it converts work to heat) which increase the temperature of blades surface.
6. TEMPERATURE
- High - temperature corrosion is chemical deterioration of metal as a result of heating. This non- galvanic form of corrosion can occur when a metal is subjected to a hot atmosphere containg oxygen, sulfur, or other compounds capable of oxidizing of the material concerned.
- For example, material used in ID fan blades have to resist sustained period at high temperature in which they may be exposed to an atmosphere containg potentially highly corrosive product of combustion.
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