How to judge the wear or corrosion of the impeller of horizontal centrifugal pump

Performance Curve Monitoring
Identification Method: Compare the pump operating curves (flow-head curve, efficiency curve) with the design curves to observe decreased pump efficiency or insufficient head. Long-term head below the design value may indicate impeller surface wear or corrosion, resulting in increased fluid flow resistance.
Professional Analysis: Impeller wear reduces the pump's energy conversion efficiency, potentially reducing pump flow and shifting the head curve to the right. Corrosion can cause impeller surface roughness, increasing friction losses and reducing pump efficiency.

Vibration and Noise Monitoring
Identification Method: Install a vibration sensor to monitor the vibration amplitude and frequency of the pump shaft and casing. Impeller wear or localized corrosion can cause unbalanced pump operation, increased vibration amplitude, and possibly abnormal noise.
Professional Analysis: Abnormal vibration is typically concentrated in multiples of the impeller frequency and the bearing frequency range. Localized corrosion or blade notches can produce periodic impulse signals that can be identified through spectrum analysis.

Pump Outlet Flow and Pressure Testing
Identification Method: Regularly record the pump outlet flow and pressure values and compare historical data. Impeller wear typically results in decreased flow and pressure. Severe corrosion can cause unstable pump performance. Professional Analysis: Impeller blade wear changes the shape of the pump's internal flow path, reducing flow and increasing energy consumption. Corrosion creates holes or pits, which can cause localized flow rate abnormalities and lead to outlet pressure fluctuations.

Visual Inspection and Impeller Inspection
Identification Method: Regularly disassemble the pump body for an impeller visual inspection, inspecting the blade surface for signs of wear, corrosion spots, or material flaking.
Professional Analysis: Wear typically manifests as thinning, smoothing, or grooves on the blade edge. Corrosion manifests as blackening, pitting, or intergranular corrosion on the blade surface, and in severe cases, perforation.

Vibration Analysis and Infrared Thermography
Identification Method: Use a vibration analyzer and infrared thermal imaging equipment to detect abnormal localized temperature and vibration on the pump shaft and casing. Wear or corrosion causes uneven fluid flow, increased friction, and localized temperature increases.
Professional Analysis: Impeller imbalance or localized blade wear increases friction and pump body temperature. Infrared imaging can quickly locate abnormal areas, allowing the severity of corrosion or wear to be determined without disassembling the pump.