Introduction to the Flow Rate of Peristaltic Pumps - Flow Range, Maximum Flow Rate, and Methods for Calculating Peristaltic Pump Flow Rate

Overview: The flow rate of peristaltic pumps is an important parameter that determines the overall efficiency and cost-effectiveness of the pump. Choosing the appropriate flow rate range can meet the requirements while reducing the overall investment and maintenance costs, resulting in high value for money. The flow rate calculation method formula for peristaltic pumps can quickly determine the required pump speed and maximum flow rate range.

I. Flow Rate Range and Maximum Flow Rate of Peristaltic Pumps

1. The flow rate of peristaltic pumps is typically tested using water at a suction head of 0.5 meters and a lift head of 0.5 meters.

2. The minimum and maximum flow rates of common peristaltic pump products are usually within the range of 0.001-30L/min. JieHeng Peristaltic Pump has more than 70 different product options with various flow rate ranges, catering to various applications ranging from 0.001ml/min to 36L/min. Some peristaltic pumps can also achieve double the flow rate by stacking two pump heads in series through a Y-shaped tee joint, combining the inlet and outlet of both heads into one.

3. The corresponding speed adjustment range for peristaltic pump flow rate is generally 0-600rpm. There are very few peristaltic pump products with higher rotational speeds, but the conventional rotational speed of peristaltic pumps is limited to 600rpm. This is because if the speed is too high, the hose will not have enough time to rebound, so increasing the speed will not significantly increase the flow rate. Additionally, a higher speed will result in faster wear on the hose.

4. Different models and specifications of peristaltic pumps can achieve different flow rate ranges by installing different peristaltic pump hoses and setting different speeds. Of course, the larger the inner diameter of the hose, the greater the flow rate of the peristaltic pump.

II. Relationship between Peristaltic Pump Flow Rate and Related Parameters

The flow rate of peristaltic pumps is affected by several parameters, including the diameter of the pump's pressure wheel, the inner diameter of the hose, rotational speed, fluid viscosity, specific gravity, suction head, lift head, and fluid temperature.

1. Generally, the flow rate of peristaltic pumps is positively correlated with the diameter of the pump's pressure wheel, the inner diameter of the hose, and rotational speed. The flow rate is also influenced by factors such as fluid viscosity, specific gravity, suction head, lift head, and temperature during operation.

2. At constant rotational speed, if viscosity, specific gravity, or suction head increases, the flow rate will decrease. This is because a higher viscosity or specific gravity, as well as a higher suction head, will offset the recoil force exerted by the hose more effectively, resulting in a lower flow rate per revolution.

3. The flow rate of peristaltic pumps is relatively unaffected by changes in lift head when operating within the rated pressure range. However, if the lift head exceeds the rated pressure and limit of the peristaltic pump, it may cause the peristaltic pump hose to expand and become thinner, leading to backflow in the pump.

4. The flow rate of peristaltic pumps is directly proportional to fluid mobility; that is, the better the fluid's mobility, the higher its flow rate. In general, as temperature increases, fluid viscosity decreases, improving fluid mobility and consequently increasing the flow rate of peristaltic pumps.

III. Determining Flow Rate

1. The flow rate of peristaltic pumps is typically determined based on the application's process requirements, aiming to meet process needs while selecting an intermediate value within that range. It is essential not to choose a too-large flow rate value since a higher flow rate can increase the speed of liquid injection but may require a larger pump size, resulting in increased volume, power consumption, and costs. Conversely, choosing a too-small flow rate value may result in longer sample injection times and inefficiencies that cannot meet efficiency requirements.

2. When determining the required flow rate, it is necessary to consider potential losses due to factors such as high fluid viscosity and specific gravity, as well as losses caused by increased suction head and decreased temperature. Based on these losses, it may be necessary to select a slightly larger flow rate peristaltic pump. If there are significant differences between the actual parameters and those of clean water, experimental testing may be required to obtain accurate reference flow rates. JieHeng Peristaltic Pump has accumulated extensive experience in fluid delivery over many years of application and provides additional guidance on flow rate determination through consultation with sales consultants.

IV. Flow Rate Calculation Method for Peristaltic Pumps

Peristaltic pumps are positive displacement pumps that generate a fixed flow rate output per revolution, making it easy to obtain desired flow rates by adjusting rotational speed. By measuring the flow rate at any given rotational speed for a peristaltic pump, it is possible to calculate the flow rate at different rotational speeds through calculations. Typically, these calculated flow rates deviate from actual flow rates by no more than 2%.

JieHeng Peristaltic Pump's flow rate parameter table provides information on pump model, tube model, rotational speed, and corresponding flow rates. For example, using Model 104KA/BT Peristaltic Pump with a 25# tube at a rotational speed of 300 revolutions per minute results in a flow rate of 279ml/min (test conditions are based on using clean water at room temperature).

If an application requires a flow rate of 200ml/min, what rotational speed should be set?

1. Calculate the flow rate generated per minute per revolution = 279/300 = 0.93ml/min based on the flow rate parameter table.

2. Set the required rotational speed = 200/0.93 = approximately 215.1rpm to achieve the desired flow rate.