Lesson 17: Methods of Pulsation Dampening in Peristaltic Hose Pumps
Objective:
By the end of this lesson, you will understand various methods of pulsation dampening used in peristaltic hose pumps. Pulsation dampening is crucial to ensure the smooth operation of the pump and prevent excessive wear on system components. We will explore different approaches to managing pulsation, their principles, and their applications.
17.1 Introduction to Pulsation Dampening
Pulsation in peristaltic hose pumps occurs due to the nature of their operation. As the rollers or shoes compress and release the hose, a pulsating flow is generated, leading to fluctuations in pressure and flow. These pulsations can cause vibrations, noise, and stress on system components, which may lead to premature failure if not properly managed. Pulsation dampening techniques are employed to smooth out these fluctuations, ensuring a more consistent flow and reducing the strain on the pump and piping system.
17.2 Methods of Pulsation Dampening
Let’s explore the different methods of pulsation dampening commonly used in peristaltic hose pump systems:
17.2.1 Air Injection in the Suction
- Principle: This method involves injecting a small amount of air into the suction line before the fluid enters the pump. The injected air acts as a cushion, absorbing the pressure spikes caused by the pulsation.
- Application: Air injection is particularly useful in applications where the fluid being pumped is not highly sensitive to air entrainment. It is an effective and simple method for reducing pulsation without the need for complex equipment.
- Considerations: Care must be taken to ensure that the amount of air injected does not interfere with the fluid’s properties or cause cavitation. Additionally, the air must be properly managed to avoid issues such as air locking.
17.2.2 Compensation Bellow
- Principle: A compensation bellow is a flexible, expandable component installed in the piping system. As the pressure fluctuates due to pulsation, the bellow expands and contracts, absorbing the pressure spikes and reducing pulsation.
- Application: Compensation bellows are often used in systems where maintaining a consistent pressure is crucial. They are effective in managing pulsation in both the suction and discharge lines.
- Considerations: The material of the bellow must be compatible with the fluid being pumped, and it should be selected to withstand the operating pressure and temperature of the system.
17.2.3 Flexible Hoses
- Principle: Flexible hoses can serve as pulsation dampeners by allowing slight changes in volume as the hose changes shape from straight to curved during operation. This volume change helps to absorb the pressure spikes associated with pulsation.
- Application: Flexible hoses are a simple and cost-effective method for managing pulsation, particularly in systems where installing additional equipment may not be feasible.
- Considerations: The effectiveness of this method depends on the hose’s flexibility and its ability to withstand the operating conditions. The hose material must be compatible with the fluid and should not degrade under repeated flexing.
17.2.4 Air Dome (Without a Bladder)
- Principle: An air dome is a chamber filled with air, installed on the discharge line. As the fluid enters the air dome, the air inside compresses, absorbing the pulsation and smoothing out the flow.
- Application: Air domes without bladders are used in systems where a simple, maintenance-free pulsation dampening solution is needed. They are commonly found in low-pressure applications.
- Considerations: The air dome must be properly sized to provide sufficient dampening, and the air volume may need periodic adjustment to maintain effectiveness as the system operates.
17.2.5 Air Dome (With a Bladder)
- Principle: Similar to an air dome without a bladder, this method involves a chamber filled with air, but with an internal bladder that separates the air from the fluid. The bladder compresses as the fluid enters, absorbing pulsation.
- Application: Air domes with bladders are used in applications where the fluid must not come into contact with air, such as in systems handling aggressive or oxygen-sensitive fluids.
- Considerations: The bladder material must be compatible with the fluid and capable of withstanding the system’s operating pressures. Maintenance may be required to replace the bladder periodically.
17.2.6 Bredel IPA (Inlet Pulsation Absorber)
- Principle: The Bredel IPA is a specialized dampening device that consists of a flexible hose mounted on a T-connection in front of the pump inlet. The hose depletes when the pump is sucking and fills back up at the moment the inlet is closed by the pump’s pressing shoe or roller. This action absorbs the pulsation before it can propagate through the system.
- Application: This method is particularly effective in applications where inlet pulsation must be carefully managed to prevent issues such as cavitation or flow inconsistencies.
- Considerations: The effectiveness of the Bredel IPA depends on the correct sizing and placement of the flexible hose. The hose material must also be selected to match the fluid’s characteristics.
17.2.7 Inline Pulsation Dampener
- Principle: An inline pulsation dampener consists of a hose placed inside a chamber charged with gas pressure. As the fluid pulses through the hose, the gas pressure in the chamber compresses, absorbing the pulsation.
- Application: Inline pulsation dampeners are ideal for high-pressure applications where precise control over pulsation is required. They are often used in systems where maintaining a stable pressure and flow rate is critical.
- Considerations: The gas pressure in the chamber must be carefully controlled to match the system’s operating conditions. Regular maintenance may be required to check and adjust the gas pressure.
17.3 Conclusion
Pulsation dampening is an essential aspect of peristaltic hose pump operation. By employing the appropriate method, you can significantly reduce the impact of pulsation, leading to smoother operation, reduced wear on system components, and longer pump life. Each method has its advantages and considerations, and the choice of dampening technique should be based on the specific requirements of the application.
17.4 Take the Next Step
Do you need help selecting the best pulsation dampening method for your peristaltic hose pump system? Contact us today for expert advice and tailored solutions to ensure optimal pump performance.
Conclusion:
In this lesson, we explored the various methods of pulsation dampening used in peristaltic hose pumps. From air injection in the suction line to inline pulsation dampeners, each technique offers unique benefits depending on the application. Understanding these methods allows you to make informed decisions that enhance the performance and longevity of your pump system.
Open questions: These questions encourage reflection on the various methods of pulsation dampening in peristaltic hose pumps, focusing on their principles, applications, and impact on pump performance and longevity.
- What causes pulsation in peristaltic hose pumps, and why is it important to manage pulsation to prevent excessive wear on system components?
- Explain the principle of air injection in the suction line for pulsation dampening. In what types of applications is this method most effective?
- How do compensation bellows work to absorb pressure spikes, and what considerations must be made when selecting a bellow for a peristaltic pump system?
- Describe how flexible hoses can act as pulsation dampeners in a peristaltic pump system. What factors affect the effectiveness of this method?
- Compare the function and application of an air dome without a bladder and an air dome with a bladder. In what situations would one be preferred over the other?
- How does the Bredel IPA (Inlet Pulsation Absorber) manage inlet pulsation, and why is it particularly effective in preventing cavitation?
- What is an inline pulsation dampener, and why is it suitable for high-pressure applications where precise pulsation control is required?
- Discuss the advantages and disadvantages of using air injection versus inline pulsation dampeners for managing pulsation in a peristaltic pump system.
- How does improper pulsation management affect the lifespan of peristaltic pump components, and what are the risks of not addressing pulsation issues?
- Why is it crucial to select the appropriate pulsation dampening method based on the specific requirements of the application, and how can this choice impact pump performance and system reliability?