In the fluid conveying link of industrial production, pump equipment selection directly affects production efficiency, operating costs and system stability. Centrifugal pumps, as the most widely used pump type, often suffer from sudden performance drops and frequent failures when facing special working conditions such as high-viscosity media and gas-containing fluids. At this time, rotary pumps among rotary positive displacement pumps have become an ideal choice to solve these conveying problems with their unique structure and working characteristics.

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Conveying high-viscosity and non-Newtonian fluids is one of the core applicable scenarios of rotary pumps. It can handle an extremely wide range of medium viscosities, from low-viscosity media such as liquefied petroleum and liquid ammonia to ultra-viscous fluids with a viscosity of up to 2,500,000 cp. For centrifugal pumps, performance conversion is required when the medium viscosity exceeds 20 mm²/s; when NPSHr is close to NPSHa and the viscosity is high, cavitation is very likely to occur. Even under ideal conditions, the upper limit of applicable viscosity is usually only 550 mm²/s. For rotary pumps, as the viscosity increases, the internal leakage decreases, the volumetric efficiency increases, and the overall efficiency improves instead. It can stably convey shear-thickening non-flowing liquids such as grease, starch paste and mud, avoiding problems such as insufficient flow and motor overload that occur with centrifugal pumps.

Working conditions with self-priming requirements should give priority to rotary pumps. Ordinary centrifugal pumps do not have self-priming capability and must be primed and vented before starting, otherwise they cannot work normally. Rotary pumps, however, inherently have self-priming characteristics. When the rotor is only in a wet state (no need to be completely submerged), it can form a vacuum to suck liquid into the pump chamber from a low position, greatly simplifying the system startup process and pipeline design.

In scenarios of conveying gas-containing liquids, rotary pumps perform far better than centrifugal pumps. Centrifugal pumps are extremely sensitive to the gas content in liquids. When the gas content exceeds 5%, problems such as reduced flow and head, increased vibration and noise will occur. In severe cases, it will also cause intensified cavitation, flow interruption and even shaft breakage accidents. Due to their strong self-priming capability, rotary pumps allow the gas content in liquids to reach up to about 20%. Although the increase in gas content will lead to a slight decrease in flow and efficiency, serious failures such as flow interruption or component damage generally do not occur.

Conveying requirements of small flow and high pressure are suitable for selecting rotary pumps. Centrifugal pumps have extremely low efficiency under small flow conditions and are difficult to achieve high outlet pressure. Rotary pumps, however, have excellent outlet pressure performance. Ordinary series products can reach 1.2 MPa, which can meet the special requirements of high-pressure conveying.

When conveying shear-sensitive media, low-shear rotary pumps are the best choice. Some media, such as biological agents, food emulsions and liquids containing suspended solids, will suffer from structural damage and quality degradation when subjected to strong shear. Cam rotary pumps and low-shear rotary pumps exert extremely gentle impact on the media during operation, and can maintain the original characteristics and integrity of the media to the greatest extent.

Working conditions requiring bidirectional operation of the pump body can select rotary pumps with reverse rotation function. Some production devices need to realize bidirectional conveying of fluids, or the inlet pipelines are prone to blockage and require backflushing for cleaning. Centrifugal pumps cannot operate in reverse, while most rotary pumps support bidirectional conveying. Only by installing safety valves on both inlet and outlet pipelines and matching reversible motors and valve systems can the demand for bidirectional operation be met.

In summary, with its unique advantages in viscosity adaptability, self-priming capability, gas tolerance, high-pressure performance, low-shear characteristics and bidirectional operation, rotary pumps have become key equipment for solving complex fluid conveying problems. In the actual selection process, it is necessary to combine medium characteristics and working condition requirements, comprehensively compare the performance characteristics of different pump types, and select the most suitable equipment to ensure the efficient and stable operation of the production system.

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.  

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