Since 1990, peristaltic pumps have been developed in China and have been widely used in various related industries and fields. peristaltic pump, English translation is Peristaltic pump. However, there are many names in the industry: peristaltic pump, metering pump, constant flow pump, hose pump, hose peristaltic pump. In terms of pumping accuracy, it belongs to metering pump and constant current pump. From the structure is a hose pump; In principle, it is a peristaltic pump. However, peristaltic pumps in the industry usually indicate that the mouth pressure is low and the flow rate is small. In the industry, the hose pump is a pump that points out that the mouth pressure is larger and the flow is larger. Let's take a comprehensive look at the peristaltic pump:

First, the composition of peristaltic pump

The 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 can be retrograde, can be dry run, and the maintenance cost is low, which constitute the main competitive advantages of peristaltic pumps.

Second, the principle of peristaltic pump

The working principle of the peristaltic pump is also well understood:

A peristaltic pump is like squeezing a fluid filled hose with a finger clamp, and the fluid moves forward in the tube as the finger slides forward. The peristaltic pump is the same principle except that the roller replaces the finger. Fluid is pumped by alternately squeezing and releasing the pump's elastic delivery hose. Just like squeezing a hose with two fingers, as the fingers move, negative pressure forms in the tube and the liquid flows with it.

Peristaltic pump is a section of pump tube between two rollers to form a "pillow" shape fluid. The volume of the "pillow" depends on the inner diameter of the pump tube and the geometry of the rotor. The flow rate depends on the product of three parameters: the speed of the pump head and the size of the "pillow" and the number of "pillows" produced by each turn of the rotor. The size of the "pillow" is generally constant (except when pumping fluids with particularly high viscosity).

Compared with a pump with the same rotor diameter, a pump with a larger "pillow" volume has a larger fluid volume transported by the rotor per revolution, but the pulsation is also larger. This is similar to the case of membrane valves. The pump that produces a smaller "pillow" volume has a smaller volume of fluid transported by the rotor per turn; Moreover, the small "pillow" formed quickly and continuously makes the flow of fluid more stable. This is similar to the way a gear pump works.

Three, the advantages of peristaltic pump

1, no pollution: fluid only contact pump pipe, not contact pump body;

2, high accuracy: repeat accuracy, high stability accuracy;

3, low shear force: it is an ideal tool for transporting shear-sensitive and erosive fluids;

4, good sealing: has good self-priming ability, can idling, can prevent reflux;

5, simple maintenance: no valves and seals;

6, with two-way equivalent flow transmission capacity; No damage will be caused to any parts of the pump under the condition of empty operation without liquid; Can produce up to 98% vacuum degree; There are no valves, mechanical seals and packing seals, and there are no such factors that create leakage and maintenance; 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 tube; Can transport a variety of grinding, corrosion, oxygen sensitive properties of materials and a variety of food; Only the hose is the part that needs to be replaced, and the replacement operation is very simple; The delivered product does not come into contact with any part except the hose.

Four, the shortcomings of peristaltic pump

1. Pressure limitation: With flexible tubes, the pressure will be limited.

2. The pump will produce a pulse flow during operation,

The solution is:

① Increase the number of rollers, the flow will be reduced

② Use pulse suppressor: The pulse suppressor is a simple positioning container, the working principle is that the air is more compressible than the liquid, the pulse flow into the container, the air bag on the liquid sinks to absorb the pulse and then gently flow out the pulse suppressor

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

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

5. Application fields

Peristaltic pump is widely used in all walks of life, including the chemical industry; Mining and metallurgical industries; Paper industry; Paint and coating industry; Food industry; Ceramic industry; The oil industry; Water treatment industry; The pharmaceutical industry; Medical device industry, etc

Six, peristaltic pump classification

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

1, speed control type peristaltic pump: with the basic control function of peristaltic pump, display speed, start and stop, direction, speed adjustment, fill and empty, power down memory, external control input and other functions.

2, flow type peristaltic pump: in addition to the basic functions, increase the flow display, flow correction, communication and other functions.

3, distribution type peristaltic pump: in addition to the basic control function to increase the flow display, flow correction, communication, liquid distribution, suction, output control and other functions.

4, custom (OEM) peristaltic pump: with a series of different flow range of peristaltic pump head, customers can design different peristaltic pump drive circuit supporting use according to the needs of their own equipment.

7. Daily maintenance

In the daily use process, try to replace the hose after a long time of use, so that it is not easy to cause the silicone tube to break, the liquid from the hose into the roller of the pump head, accompanied by corrosive liquid into the roller gap, the pump head should be removed and cleaned in time to avoid freezing in the roller gap after weathering, which will cause the phenomenon of the pump head stuck. The hose should be replaced in time according to the frequency of use of the specific pump during use, or often move the position, if the liquid is highly corrosive, please select the appropriate material of the imported hose to avoid damage to the pump.