A peristaltic pump consists of three parts: the driver, the pump head and the hose. The fluid is isolated in the pump tube, the pump tube can be quickly replaced, the fluid is reversible, it can be run dry, and the maintenance cost is low. These characteristics constitute the main competitive advantages of peristaltic pumps.

How do peristaltic pumps work?

A peristaltic pump is like squeezing a fluid-filled hose with your fingers, moving the fluid forward as your fingers slide forward. Peristaltic pumps are also the same principle, but the fingers are replaced by rollers. Fluid is pumped by alternately squeezing and releasing the elastic delivery hose of the pump. Just like squeezing the hose with two fingers, with the movement of the fingers, a negative pressure is formed in the tube, and the liquid flows with it.

The peristaltic pump forms a "pillow"-shaped fluid in a section of pump tube between two rotating rollers. The volume of the "pillow" depends on the inner diameter of the pump tubing and the geometry of the rotor. The flow rate depends on the product of the speed of the pump head, the size of the "pillow", and the number of "pillows" produced by each revolution of the rotor. The dimensions of the "pillow" are generally constant (except when pumping very viscous fluids).

Comparing pumps with the same rotor diameter, a pump with a larger "pillow" volume will deliver a larger volume of fluid per revolution of the rotor, but also generate larger pulsations. This is similar to the case of membrane valves. In a pump that produces a smaller "pillow" volume, the volume of fluid transported by the rotor per revolution is also smaller; moreover, the small "pillow" formed rapidly and continuously makes the flow of the fluid more stable.This is similar to how a gear pump works.

How does a linear pump work

TH152 OEM peristaltic pump  works

PF25 peristaltic pump head works

Advantages

1. No pollution: the fluid only contacts the pump tube, not the pump body;

2. High precision: repeatability, high stability and precision;

3. Low shear force: it is an ideal tool for conveying shear-sensitive and aggressive fluids;

4. Good sealing: It has good self-priming ability, can be idling, and can prevent backflow;

5. Simple maintenance: no valves and seals;

6. It has the ability to convey the same flow in both directions; it will not cause any damage to any part of the pump under the condition of no liquid idle operation; it can generate a vacuum degree of up to 98%; 

there is no valve, mechanical seal and packing sealing device, so there is no leakage of these. and maintenance factors; it can easily transport solid, liquid or gas-liquid mixed phase fluid, allowing the solid diameter contained in the fluid to reach 40% of the inner diameter of the tubular element; 

it can transport various materials with abrasive, corrosion, oxygen-sensitive properties and various Food, etc.; only the hose is the part that needs to be replaced, and the replacement operation is extremely simple; the conveyed product does not come into contact with any part except the hose.

limitation

1.Pressure limitation: The use of flexible pipes will limit the pressure.

2. The pump will generate a pulse flow when it is running,

The solution is:

①Increase the number of rollers, the flow will decrease

②Use the pulse suppressor: The pulse suppressor is a simple positioning container. The working principle is that because the air is more compressible than the liquid, the pulse flow enters the container, and the air bag on the liquid sinks to absorb the pulse and then flows out of the pulse suppressor smoothly.

3. The flow rate changes with time and will attenuate. (due to hose wear)

The outlet pressure of the pump has certain limitations, generally not more than 0.3MPa, usually between 0.1-0.2MPa.

Application field

Chemical industry; mining and metallurgy industry; paper industry; paint and coating industry; food industry; ceramic industry; petroleum industry; water treatment industry; pharmaceutical industry; medical device industry;

Pharmaceutical industry application: The application of peristaltic pump in the pharmaceutical industry is mainly used for drug coating granulation and liquid medicine dispensing. Spray drying granulator is also called drying granulator and fluidized bed granulator. It is a machine used to spray the surface of various granule instant materials with special sugar coating and form granules after drying. These granulators themselves have a specific drying heat source, which can serve the purpose of evaporating water, but water evaporation and particle formation are dynamic, so the amount of liquid and water that needs to be injected must be very accurate to ensure a certain humidity of the particles. Facilitates the perfect formation of particles.

Classification

The peristaltic pump is used to obtain the required flow, so according to the operation and use of the peristaltic pump, it is divided into:

1. Speed-regulated peristaltic pump: It has the basic control functions of peristaltic pump, such as display speed, start and stop, direction, speed adjustment, filling and emptying, power-off memory, external control input and other functions.

2. Flow type peristaltic pump: In addition to the basic functions, functions such as flow display, flow correction, and communication have been added.

3. Distribution type peristaltic pump: in addition to the basic control functions, the functions of flow display, flow correction, communication, liquid volume distribution, back suction, and output control are added.

4. Customized (OEM) peristaltic pump: It has a series of peristaltic pump heads with different flow ranges. Customers can design different peristaltic pump drive circuits to be used together according to the needs of their own equipment.

System composition

The peristaltic pump system consists of three parts: the peristaltic pump driver, the peristaltic pump head, and the peristaltic pump tubing.

select tube

Condition as peristaltic pump hose

It has a certain elasticity, that is, the hose can quickly recover its shape after being radially compressed

Has a certain wear resistance

Ability to withstand pressure

No leakage (good air tightness)

Low adsorption, good temperature resistance, not easy to age, not swelling, corrosion resistance, low precipitates, etc.

Choose a pump head

Choice of single and multi-channel delivery fluids

Is it easy to change the hose

Is it easy to fix the hose

The pressure tube gap is fine-tuned by ratchet or other methods to adapt to different wall thickness of the hose or to achieve fine-tuning of pressure

Roller selection: 6-roller structure with slightly larger relative flow; 10-roller structure with smaller fluid pulsation

Whether the trigger structure is smart and whether it is convenient to open the card

select drive

Whether flow control is required

Whether volume distribution is required

What is the flow range

Whether the overall structure is reasonable and the operation is convenient

Whether the flow accuracy and liquid volume accuracy meet the requirements

Special requirements: protection level, explosion-proof level, etc.

External control requirements: equipment matching, operation methods, etc., such as RS232. RS485 communication, 0-5V external control speed regulation, pulse speed regulation, etc.

routine maintenance

In the process of daily use, try to replace the hose after long-term use, so as not to cause the silicone tube to rupture, the liquid will flow out of the hose into the roller of the pump head, and the corrosive liquid will flow into the gap of the roller. The pump head should be disassembled and cleaned so as not to freeze in the roller gap after weathering, which will cause the pump head to be stuck. During use, the hose should be replaced in time according to the frequency of use of the specific pump, or the position should be moved frequently. If the liquid is highly corrosive, please select the imported hose of the corresponding material to avoid damage to the pump.