definition of cavitation in centrifugal pump|when does pump cavitation occur

This project was concerned with the analysis and development of a decanter centrifuge. The aim of the project was to increase the understanding of the operation of the machine, and identify .

Cavitation is a phenomenon that occurs in centrifugal pumps when the pressure of the liquid being pumped drops below its vapor pressure, causing the formation of vapor bubbles. These vapor bubbles collapse as they move to a higher pressure region, leading to the formation of tiny implosions. This process creates intense shock waves and high-velocity liquid jets that can cause damage to the pump components. In this article, we will delve into the definition of cavitation in centrifugal pumps, its impacts on pump performance, the reasons for cavitation, and how to avoid it.

Cavitation in a centrifugal pump occurs when the pressure of the liquid drops below its vapor pressure, leading to the formation of vapor bubbles. As these bubbles collapse in high-pressure zones, they generate shock waves, causing erosion and damage to pump

Impacts of Cavitation on Pump Performance

Cavitation can have detrimental effects on the performance and efficiency of a centrifugal pump. Some of the key impacts of cavitation include:

1. **Decreased Pump Efficiency**: Cavitation reduces the pump's ability to generate the required flow rate and pressure, leading to a decrease in overall efficiency.

2. **Vibration and Noise**: The implosion of vapor bubbles creates vibrations and noise within the pump, which can be detrimental to the pump's structural integrity and lead to premature failure.

3. **Damage to Pump Components**: The high-velocity liquid jets produced during cavitation can erode pump impeller blades, casing walls, and other components, leading to reduced pump lifespan and increased maintenance costs.

4. **Loss of Performance**: Cavitation can result in a loss of pump performance, causing fluctuations in flow rate and pressure, which can impact the overall system operation.

Reasons for Cavitation & How to Avoid the Same

# Why is Cavitation Bad?

Cavitation is considered bad for centrifugal pumps due to the following reasons:

1. **Damage to Pump Components**: Cavitation can cause erosion and pitting on the pump impeller and casing, leading to reduced efficiency and increased maintenance costs.

2. **Noise and Vibration**: The noise and vibration produced during cavitation can be detrimental to the pump's operation and lead to premature failure.

3. **Loss of Performance**: Cavitation can result in a loss of pump performance, affecting the overall system efficiency and operation.

# Pump Impeller Cavitation Damage Pictures


The image above shows the damage caused to a pump impeller due to cavitation, highlighting the erosion and pitting on the impeller blades.

# When Does Pump Cavitation Occur?

Pump cavitation can occur under the following conditions:

1. **High Pump Speed**: Operating the pump at a speed higher than the recommended limit can lead to cavitation.

2. **Low NPSH**: Insufficient Net Positive Suction Head (NPSH) can cause cavitation as the pressure at the suction side drops below the vapor pressure of the liquid.

3. **Blockages or Restrictions**: Any blockages or restrictions in the suction line can create conditions for cavitation to occur.

# Causes of Pump Cavitation in Centrifugal Pumps

Some common causes of pump cavitation in centrifugal pumps include:

1. **High Pump Speed**: Operating the pump at speeds higher than recommended can create low-pressure zones, leading to cavitation.

2. **Incorrect Pump Sizing**: Selecting a pump with a capacity that exceeds the system requirements can lead to cavitation.

3. **Air or Gas Entrapment**: Air or gas entrapped in the pump casing can cause cavitation during operation.

# Positive Displacement Pump Cavitation

Positive displacement pumps can also experience cavitation, which occurs when the pressure within the pump drops below the vapor pressure of the liquid being pumped. This can lead to damage to the pump components and a decrease in pump efficiency.

# How to Solve Pump Cavitation

To solve pump cavitation issues, the following steps can be taken:

1. **Increase NPSH**: Ensure that the Net Positive Suction Head (NPSH) available is greater than the required NPSH to prevent cavitation.

2. **Reduce Pump Speed**: Operating the pump at a lower speed can help reduce the likelihood of cavitation.

3. **Eliminate Blockages**: Ensure that the suction line is free from any blockages or restrictions that could lead to cavitation.

4. **Proper Pump Sizing**: Select a pump that is appropriately sized for the system requirements to prevent cavitation.

Reasons for Pump Cavitation

Some common reasons for pump cavitation include:

1. **High Pump Speed**: Operating the pump at speeds higher than recommended can create low-pressure zones, leading to cavitation.

2. **Insufficient NPSH**: Inadequate Net Positive Suction Head (NPSH) can result in cavitation as the pressure at the suction side drops below the vapor pressure of the liquid.

3. **Air or Gas Entrapment**: Air or gas entrapped in the pump casing can cause cavitation during operation.

Cavitation in Well Submersible Pump

Pump cavitation is a potentially damaging problem in pumps that are not properly configured or being used for their intended application. Here, we’ll explore what causes …

FLSmidth’s Decanter brand has earned its proud reputation throughout 20 years of serving the centrifuge industry. Decanter centrifuges and services are found on 6 conti-nents. No matter where a customer is located, no matter what the application, FLSmidth is ready to provide the very best Decanter products, parts and services available.

definition of cavitation in centrifugal pump|when does pump cavitation occur