A peristaltic pump can be used to transport air, but there are the following issues:
1. Airtightness. Based on the principle of a peristaltic pump, there are three points where airtightness is an issue.
① Inlet and outlet: The airtightness of the inlet ensures that the desired gas is transported, therefore a certain level of airtightness is required. Similarly, the outlet needs a certain level of airtightness for the gas collection device.
② Hose material: Generally, hoses have a certain degree of airtightness, but if the gas being transported is volatile, slight leaks may occur. Therefore, if a high gas volume is required, a high-airtightness 3603 hose should be considered; otherwise, a peristaltic pump-specific hose is sufficient.
③ Number of Rollers: The principle of a peristaltic pump is that a sealed space is formed between every two rollers. As the motor drives the rollers, the rollers push this sealed space forward, creating a conveying effect. Therefore, to achieve a better gas conveying effect, it is essential to ensure that a sealed space is formed when the rollers squeeze the tubing. Thus, choosing a peristaltic pump with 3 or 4 rollers will result in better air delivery.
2. Pressure Issues: Since air is stored in a sealed space, when a peristaltic pump delivers air, it draws air out of this sealed space, creating a vacuum. This means the passive suction at the inlet increases, making the peristaltic pump’s delivery increasingly difficult. To solve this problem, a venting device needs to be added to the sealed space or pipeline.
3. Application Issues: The actual application of peristaltic pumps for air delivery is not widespread, but each application is a high-tech or technically challenging device. The most typical application is in online water quality monitoring instruments. These instruments use fluorescence analysis to analyze the composition of wastewater by irradiating it with infrared light or other special light. Therefore, the wastewater sample only needs to be drawn to a certain height, and the remaining pipe is still filled with gas (air).