As we all know, for many years, the peristaltic pump has been widely used in pharmaceutical industry because of its small size, high transmission accuracy, corrosion resistance, good control and other design advantages, which can generally meet the different special requirements of users in various industries.
For example, it is used in automatic quantitative feeding, batching, filling or injecting various adhesives, cleaning agents, disinfectants and so on in our country's pharmaceutical industry. These applications are either due to the small amount of material, the dosage must be precisely controlled to ensure the mixing or filling accuracy, or because the material has a certain degree of corrosiveness, the general pump used is difficult to meet the requirements of these users, most of them use peristaltic pump.
Xiaobian as a pharmacist in the pharmaceutical industry for decades, in actual production, it is not difficult to find that many users of peristaltic pump operation principle and its advantages and disadvantages are not very well understood, so in production applications can not be very good "with its advantages, avoid its disadvantages". To this end, according to their own learning and understanding, the small edition collected this "on peristaltic pump mechanical principles and their advantages and disadvantages" article, and share it with you, I hope that the appreciator can like it. Because of the limited knowledge level of the Xiaobian, we welcome you to judge!
So let's start with what is called peristaltic pump? How does it work? In fact, the peristaltic pump is also called constant current pump or hose pump, and its mechanical operation principle is very simple. Because it operates by alternately repeating mechanical extrusion and release of the pump pipe to pump the fluid. The reason is called peristaltic pump, but also because the movement of its pump pipe like a worm moving, peristaltic pump is to clamp hose between the mechanical rotor and stator, in order to achieve the purpose of pumping fluid. (See Fig. 1) When a peristaltic pump works, a section of the pump pipe between the two rollers forms a pump chamber. The size of the pump chamber depends on the inner diameter of the pump pipe and the size of the rotor (see Fig. 2, 3, 4). The theoretical flow rate of peristaltic pump is the volume of pump chamber. Comparing with the pump with the same rotating diameter, the pump with larger pump chamber is produced. The volume of fluid transported by the rotor in each rotating circle is also larger, but the pulse is also larger. On the contrary, the pump that produces a smaller pump chamber has a smaller volume of fluid transported by its rotor per turn, but it produces smaller pulses, but rapid and continuous pumping can ideally reduce pulses. Therefore, in some cases of small flow, very small pulse requirements, the choice of pump head is very important.
1. Illustration of the mechanical operation of peristaltic pump.
1.1 when the peristaltic pump works, a pump chamber between the two rollers will form a pump chamber.
1.2 the peristaltic pump head is divided into two parts: rotor and pump housing. The pump tube is fixed between the rotor and the pump housing, and the runner compacts the pump tube in the pump.
1.3 the runner on the rotor passes through the pump pipe in turn to push the fluid in the tube forward. The pump tube after the runner is rolled restores its original shape because of its elasticity, and forms a vacuum at the suction end of the pump tube. The liquid is sucked in because of the vacuum.
1.4 There is a distance between the runners, this distance will make the pump tube into a closed space that is the pump chamber, the volume of the pump chamber is related to the diameter of the pump tube and the rotating diameter of the runner and wheel spacing. The velocity depends on the product of the speed of the runner on the pump head and the pump chamber size.
2, specify:
2.1 The negative pressure and liquid suction of peristaltic pump are produced by the elastic force of the pump tube itself. The rebound speed and time of the pump tube are fixed, and the rebound force of the pump tube is also fixed. Because of this characteristic, the suction stroke produced by peristaltic pump will be affected by the hardness of the pump tube. Common experimental peristaltic pump can not quickly convey the liquid with poor fluidity and slow free flow. To convey the liquid with poor fluidity and high viscosity, it is necessary to adopt higher pressure hardness, higher resilience and stronger peristalsis. Moving pump.
2.2 the peristaltic pump will produce a fixed volume of liquid every turn. Therefore, peristaltic pump can adjust the speed of the pump to change the flow rate, while the transmission accuracy is very high.
3. Advantages of peristaltic pump:
3.1 no pollution: the fluid only contacts the pump tube and does not touch the pump body.
3.2 high accuracy: repeatability, accuracy and stability.
3.3 low shear force: an ideal tool for transporting shear sensitive and aggressive fluids.
3.4 good sealing performance: good self-priming ability, idling, preventing backflow.
3.5 peristaltic pump maintenance is simple: no valves and seals, hose is the only vulnerable parts.
3.6 liquid, gas, solid or multiphase mixture can be pumped.
4, the disadvantages of peristaltic pump:
4.1 peristaltic pump will generate pulses.
4.2 the peristaltic pump tube is easy to damage.
4.3 the peristaltic pump can not achieve too high pressure.
5, common peristaltic pump and pump head type:
5.1 common peristaltic pump type: BT-100EA/153Yx, BT-100CA/153Yx.
5.2 common peristaltic pump head models: 153Yx, 253Yx, 353Yx, 104K, 204K, 304K.