In the last issue, we introduced the problem of filling dripping with peristaltic pumps (1), and today we will continue to talk about it.
Phenomenon 2: After the peristaltic pump is stopped, there will be viscous liquid hanging on the filling needle at the filling port. Cause analysis: In this case, the main reason is that the viscous liquid is high, and the flow speed of the liquid at the filling port is not enough to overcome the adhesion between the liquid and the needle mouth, resulting in the liquid hanging on the filling needle.
Solution: In the filling process, the filling needle should be moved up and down, so that the filling needle can contact the liquid to be filled during the filling process, and then the filling needle is lifted after the filling is completed, so that the situation of the liquid hanging needle can be effectively solved. After the filling is completed, the suck-back function of the drive is adopted (the dispensing type peristaltic pump has this function), so that after the filling is completed, the viscous liquid hanging on the needle can be quickly cut off through the back-sucking of the pump head, which can also effectively solve the situation of liquid hanging on the needle.
Precautions for use.
1. The pump relies on the compression hose for fluid and transmission. When the pump is not working, the pressure block can be loosened to keep the hose in its natural uncompressed state, thus extending the service life.
2. When selecting the parameters of the pump, the theoretical flow rate is greater than the actual flow, generally greater than 30%. Because the pump tubing is soft, it generates very little negative pressure and discharge pressure. If the liquid being conveyed has a certain viscosity or the pipe has a certain length, part of the actual flow will be lost. So in order to achieve the required flow rate, the theoretical flow rate is slightly higher than the actual flow rate.
3. Peristaltic pump hoses are divided into many types, including imported hoses and domestic hoses. Due to the high wear of the hose at the pump head, good compression elasticity and tear resistance are required, and special hoses can be used, which can save the time of replacing the hose and increase the time of pump operation.