Positive displacement pumps are applied in a very wide range of scenarios in industrial production, but many practitioners have relatively vague cognition of the classification boundaries of pump products. Many commonly used rotary pumps in daily practice actually fall into the broad category of rotary pumps. Pump types with different structures differ significantly in medium adaptability, operating parameters and maintenance costs. Only by sorting out their performance characteristics can we make reasonable judgments during pump selection for actual working conditions.

-Bonve Pumps Cam-Type Twin Rotor Pump-

 Gear Pumps

Gear pumps convey media through the rotation of a pair of meshing gears inside the casing; the driving gear drives the driven gear to operate synchronously, and a tiny clearance is reserved between the gears and the pump housing. When the gears rotate in a fixed direction, the gear teeth on the suction side disengage from meshing to form a vacuum and suck in the medium, the medium is pushed to the discharge side along with the rotation of the gears, and the cavity shrinks after meshing to discharge the medium.

Internal gear pumps have only two moving parts and adopt a single seal chamber structure. They boast extremely prominent self-priming capacity and deliver stable, pulse-free output at the outlet. Their flow rate is not affected by back pressure fluctuations, they support bidirectional operation with a low required net positive suction head (NPSHr), their end face clearances are adjustable, and they are low in maintenance difficulty. The disadvantages include low upper limit of rotating speed, limited pressure capacity, one-side bearing immersed in the medium, and cantilever load borne by the pump shaft.

External gear pumps support high-speed and high-pressure output, with bearings supported at both ends and lower operating noise. However, all four shaft sleeves are immersed in the medium, so they cannot handle media containing solid particles, and the end face clearances are non-adjustable.

 Screw Pumps

Screw pumps drive the medium to be discharged axially along the spiral grooves through the rotating meshing of screws, and are divided into three categories: single screw pumps, twin screw pumps and triple screw pumps.

Single screw pumps can handle media with high solid content and high viscosity, deliver high output pressure, and have excellent adaptability to mud and silt, with the mechanical seal located on the inlet side. But they do not support dry running, cannot adapt to high-temperature working conditions, involve high maintenance difficulty and cost, require large installation space, and demand high precision in screw processing and assembly.

Triple screw pumps cover a wide range of pressure and flow rates, are compatible with a great variety of media and a wide viscosity span, feature high rotating speed and strong self-priming capacity, deliver uniform flow with slight vibration, exert weak shearing effect on the medium, have high tolerance to gas-liquid impurities, and have a sturdy structure for easy maintenance. The disadvantage is that high precision is required for screw processing, and their performance is sensitive to changes in medium viscosity.

 Lobe Pumps

Cam rotor pumps are driven by external gears, which drive two conjugate cams to rotate reversely and synchronously to push the medium, and are divided into two-lobe and multi-lobe types.

This type of pump can convey media containing medium-sized particles, involves no direct metal-to-metal contact, exerts extremely low shearing action, supports cleaning-in-place (CIP) and sterilization-in-place (SIP), has strong self-priming capacity and delivers pulse-free outlet flow. The disadvantages are that they need to be equipped with synchronous gears and two sets of seals, and their self-priming capacity decreases significantly when handling low-viscosity media.

 Vane Pumps

The cylindrical rotor of a vane pump is provided with radial grooves, in which freely sliding vanes are installed, usually 6 pieces or more.

This type of pump has moderate flow rate and rotating speed, is suitable for low-viscosity media, and is the preferred pump type for solvents and liquefied gases. It supports short-time dry running and has strong self-priming capacity. The disadvantages include two stuffing boxes on some models, complex pump housing structure, and inapplicability to high-pressure, high-viscosity and abrasive media.

 Rotary Piston Pumps

The arc-shaped rotor wings of a rotary piston pump rotate along the circumferential flow channel; the cavity on the inlet side expands to suck liquid, and the cavity on the outlet side meshes to discharge liquid.

This type of pump has high efficiency when handling low-viscosity media; the rotor is made of non-abrasive material with smaller clearance, boasts excellent self-priming performance, features weak shearing and high outlet pressure, can handle media with high solid content, and is easy to disassemble and clean. The disadvantage is that synchronous gears and two sets of seals are required.

 Hose Pumps

Hose pumps, also known as peristaltic pumps, consist of a pump housing, rotor, hose and transmission device, and convey media by the rotor squeezing the flexible hose.

In this pump type, the medium is completely isolated from mechanical components, the hose is the only wearing part in the whole pump, cleaning is convenient and fast, it supports dry running and self-priming, can handle materials with 60% solid content, abrasive media and gas-containing media, and features weak shearing, high precision and low maintenance cost. The disadvantages include low pressure capacity, regular hose replacement required, pulsating flow, and vulnerability to leakage under overload.

Rotary pumps with different structures have their own performance focuses. In actual pump selection, comprehensive judgment must be made in combination with medium characteristics, working condition parameters and maintenance costs, so as to match the most suitable equipment.

Bonve pump always adheres to the philosophy of "Wholeheartedly Making Good Rotor Pumps," committed to providing global customers with customized conveying and mixing solutions. If you have technical inquiries, selection needs, case references, or other cooperation intentions related to Bonve rotor pumps, please feel free to contact us.  

Service Hotline: 0574-87588986 13586591794  

Official Website: www.bvpumps.com  

Business Email: market@bonvepumps.com  

We look forward to working with you to drive efficiency and innovation in industrial fluid transmission with precision technology.