Types and uses of rotary pumps

Rotary pump is a type of positive displacement pump that delivers liquid by changing the volume of the working chamber through the rotational motion of the rotor. Its types are diverse and widely used. The following are common types and their uses:

**1、 The main types of rotary pumps**

1. * * Gear pump**

-External gear pump: Two gears with external meshing, simple structure, used for conveying low viscosity liquids such as lubricating oil, fuel, hydraulic oil, etc.

-Internal gear pump: The gear meshes with the internal ring gear, resulting in minimal flow pulsation, making it suitable for conveying high viscosity liquids (such as in the chemical and food industries).

-* * Purpose * *: Automotive lubrication system, machine tool hydraulic system, fuel delivery, etc.

2. * * Screw pump**

-Single screw pump: The rotor is a spiral screw and the stator is a rubber liner, suitable for conveying media containing particles or fibers (such as sewage and sludge).

-Twin screw pump: Two screws engaged, non pulsating conveying, used for high-precision applications (such as crude oil transportation and chemical media).

-Triple screw pump: High pressure, low noise, suitable for high-pressure delivery of hydraulic oil and fuel.

-* * Purpose * *: Petrochemical industry, sewage treatment, ship fuel system.

3. Sliding vane pump (vane pump)**

-The rotor slot is equipped with sliding plates, which are tightly attached to the pump chamber under centrifugal force during rotation, and the volume changes to achieve conveying.

-Purpose: Automotive fuel pump, hydraulic system, vacuum equipment.

4. * * Cam pump (rotary piston pump)**

-The rotor is cam or petal shaped, which squeezes liquid through rotation and is suitable for media with high viscosity or solid particles.

-* * Uses * *: Food industry (jam, chocolate), chemical industry (adhesive), wastewater treatment (slurry).

5. Roots pump (double rotor pump)**

-Two "8" - shaped rotors rotate in opposite directions, delivering smoothly and efficiently, suitable for high viscosity or gas containing liquids.

-* * Purpose * *: Petrochemical, papermaking industry, and liquid medicine transportation.

6. * * Piston pump**

-The rotor drives the plunger to reciprocate, with strong high-pressure capability but complex structure.

-* * Purpose * *: High pressure cleaning equipment, hydraulic systems, oil extraction.

7. * * Peristaltic pump (hose pump)**

-The rotor squeezes the hose for conveying, which is pollution-free and suitable for sensitive media.

-* * Purpose * *: Laboratory, pharmaceutical, food and beverage industries.

2、 The core use of rotary pumps**

1. High viscosity liquid transportation: Gear pumps, cam pumps, screw pumps are suitable for transporting asphalt, glue, syrup, etc.

2. * * Medium containing particles or fibers * *: Single screw pumps and cam pumps can treat sewage, mud, pulp, etc.

3. High pressure scenario: Piston pumps and three screw pumps are used for hydraulic systems and high-pressure cleaning.

4. * * Hygiene grade applications * *: Cam pumps and peristaltic pumps made of food grade stainless steel or designed for hygiene are used for beverages and dairy products.

5. * * Precision flow control * *: Twin screw pumps and gear pumps are used for chemical quantitative injection and fuel injection.

6. Corrosion resistant medium: Rotary pumps made of special materials (such as fluoroplastics) are used for transporting acidic and alkaline liquids.

**3、 Key factors for selection**

1. * * Medium characteristics * *: viscosity, corrosiveness, solid content.

2. * * Working condition requirements * *: flow rate, pressure, temperature.

3. * * Industry standards * *: The food industry requires hygiene certification, and the chemical industry requires corrosion-resistant design.

4. * * Maintenance cost * *: The slide pump requires regular replacement of slides, and the peristaltic pump requires replacement of hoses.

**Summary**

There are various types of rotary pumps, suitable for various fields such as industry, agriculture, food, medicine, etc. When selecting, it is necessary to consider the characteristics of the medium, working conditions, and maintenance costs to choose the most suitable type.

For example, a single screw pump can be used to transport sewage, a cam rotor pump is suitable for high viscosity food media, and a plunger pump or three screw pump is required for high-pressure scenarios.