A variable speed peristaltic pump is a type of pump that operates using a principle called peristalsis. Peristalsis refers to the rhythmic contraction and relaxation of muscles to create a wave-like motion. In the case of a peristaltic pump, this motion is used to move fluid through a tube or a flexible hose.
Working principle of a peristaltic pump
The basic working principle of a peristaltic pump involves squeezing and releasing a flexible tube or hose at regular intervals. The pump typically consists of a rotor with several rollers or shoes that compress the tube against a fixed housing or track.
Here’s how it works:
- Tube arrangement: The fluid to be pumped is contained in a flexible tube or hose. The tube is positioned between the rotor and the housing in such a way that the rotor’s rollers or shoes can squeeze and release the tube.
- Squeezing action: As the rotor rotates, the rollers or shoes come into contact with the tube and squeeze it against the housing. This squeezing action creates a seal and prevents fluid from flowing backward.
- Fluid displacement: As the rotor continues to rotate, the squeezing action moves along the length of the tube, pushing the fluid ahead of it. This creates a positive displacement effect, where a fixed volume of fluid is moved with each rotation of the rotor.
- Tube relaxation: After the rollers or shoes pass, the tube relaxes, allowing new fluid to enter behind the roller and be ready for the next squeezing action.
The speed of the peristaltic pump can be adjusted by controlling the rotational speed of the rotor. By changing the rotational speed, you can vary the frequency and speed of the squeezing action, which in turn affects the flow rate of the pumped fluid. Slower rotation speeds result in lower flow rates, while faster rotation speeds increase the flow rate.
Variable speed peristaltic pumps are commonly used in various industries, including medical, laboratory, and industrial applications. They are particularly useful when precise control of flow rate and gentle pumping action is required, as the peristaltic pumping mechanism is non-invasive and does not contaminate the fluid being pumped since it only comes into contact with the tube or hose.
Design characteristics of variable speed peristaltic pump
When it comes to more details about variable speed peristaltic pumps, here is some further information:
- Pump head design: Variable speed peristaltic pumps usually have a replaceable pump head design. This means that pump heads of different sizes and materials can be replaced to suit different application needs. The pump head usually consists of one or more peristaltic channels, each with a corresponding compression element (such as a roller or shoe).
- Flow control: By adjusting the speed, the flow control of the variable speed peristaltic pump can be achieved. Higher RPM will result in higher flow, while lower RPM will reduce flow. This makes variable speed peristaltic pumps ideal for applications requiring precise flow control.
- Countercurrent prevention: Due to the working principle of peristaltic pump, the liquid will not backflow when the pump stops running. This is because when the pump stops, the compression element no longer squeezes the pipe, so no liquid flows through it.
- Low shear applications: Because of the way peristaltic pumps work, they produce low shear forces on liquids. This makes the variable speed peristaltic pump ideal for handling liquids that are sensitive to shear, such as cell culture fluids in biomedical applications.
- Accurate flow and metering: Due to the positive displacement characteristics of the peristaltic pump, accurate flow and metering can be achieved. This makes variable speed peristaltic pumps useful in applications where precise dosing or filling of liquids is required.
- Highly controllable: The variable speed peristaltic pump is highly controllable and can be adjusted precisely according to the need. This makes them ideal for laboratory research, pharmaceutical manufacturing, food processing, etc., where the precise movement and metering of liquids is required.
All in all, the variable speed peristaltic pump is a reliable and versatile pump that provides precise flow control and low shear liquid delivery through peristaltic motion and adjustable speed. They are widely used in many industries, including medical, laboratory, industrial and environmental fields.
