Rotary Vane Pumps

What are Vane pumps

Rotary vane pumps are a very popular form of positive displacement pump that have been used around the world for many decades. They consist of vanes mounted on to a rotor that rotates inside the pump chamber. In some cases, these vanes can have variable length and/or be tensioned to maintain contact with the walls as the pump rotates.

BENEFITS OF ROTARY VANE PUMPS

Rotary vane pumps deliver a gentle low shear action so that the structure of the pumped fluid is not affected.

By virtue of their inherent energy and mechanically efficient designs, positive displacement rotary and sliding vane pumps are perfectly suited to offering operators immediate high value advantages and solutions in fulfilling their energy saving initiatives. In reviewing a list of the most common system characteristics that need to be considered in pumping applications, positive displacement pumps outperform centrifugal pumps is almost all of them.

Depending on the technology chosen, rotary vane pumps may offer:

• Ability to self-prime.
• Constant flow that is relatively independent of changes in system pressure.
• Constant flow that is relatively independent of changes in viscosity.
• Ability to handle low and medium viscosity products.
• Can handle thin liquids at relatively higher pressures.
• Develop a good vacuum.
• Ability to run dry for short periods.
• Higher efficiency across varying system pressures.

WHERE TO USE ROTARY VANE PUMPS

Rotary vane pumps are used in many different applications due to their all-round versatility. They can deliver flows up to 450 m3/hr and differential pressures of 14 bar.  They are typically found in dispensing applications, transferring fuels, low flow circulation duties and some specialist applications such as pumping chocolate.

Rotary Vane pumps are also commonly used for pumping viscous fluids such as oils and syrups, as well as this Vane pumps can are excellent at handling a variety of solvents such acetone. When it comes to light, non-lubricating fluids such as alcohols and solvents then vane pumps are very often the best solution as they are self-lubricating and can (with the correct design) cope with low net positive suction head (NPSH).

WHY BUY ROTARY VANE PUMPS FROM AXFLOW

AxFlow UK has been supplying rotary vane pumps for over 50 years as a result we are one of the leading experts when it comes to rotary vane pumps in the UK.

AxFlow offers 10 different ranges of vane pumps from three manufacturers; Blackmer,  Gruppo Aturia,  and Mouvex giving us the widest selection of vane pumps in the UK. Our range of vane pumps includes cast iron and stainless steel models, mag drive options, vane pumps designed for low viscosity liquids such as LPG, API 676 and pulseless pumps.

How to select Vane Pumps

When selecting a rotary vane pump, a range of factors should be taken into consideration to ensure that it meets your specific needs and application requirements. Here are three key factors to consider:

• Flow Rate and Capacity: Determine the required flow rate and capacity for your application. This involves calculating the volume of gas or fluid that needs to be pumped per unit of time. Make sure the rotary vane pump you choose can handle the necessary flow rate without excessive backpressure, which could affect performance.

• Vacuum Level or Pressure Range: Different applications require specific vacuum levels or pressure ranges. Consider the required vacuum level (e.g., deep vacuum, high vacuum, low vacuum) or pressure range (positive or negative pressure) that your application demands. Ensure that the selected rotary vane pump can achieve and maintain the desired level within your application's operating conditions.

• Chemical Compatibility and Material Selection: Evaluate the compatibility of the pump's materials with the gases or fluids you will be handling. Some applications may involve corrosive or abrasive substances, so it's crucial to choose a pump with materials that can withstand these conditions. Pay attention to the materials used for the pump housing, vanes, seals, and other critical components.

OPERATING PRINCIPLES

Standard rotary vane pumps operate on the principle of the eccentricity between the shaft and the pump casing bore (stator). Rotary vane pumps come in two types: the flexible vane and sliding vane.

FLEXIBLE VANE PUMPS

In flexible vane pumps the vanes are made from a malleable material. The tips of the vanes used in flexible vane pump are lobe shaped and when rotating they flex in order to maintain contact with the walls of the stator, thereby trapping the fluid in small pockets or cavities. When the discharge pipe is reached the trapped fluid is released from the pockets.

SLIDING VANE PUMPS

In sliding vane pumps, the vanes are made from a rigid material and do not flex when rotating. The rigid vanes that are free to slide into or out of slots in the pump rotor by way of springs or pressure-activated pins in the rotor. As the rotor turns, the vanes move out of the rotor slots creating a void at the inlet port and drawing fluid in. The fluid is transferred from the inlet port to the discharge port between the vanes. At the outlet, the fluid is discharged and the pumping chamber is reduced and the vanes slide back into the

CHOOSING THE RIGHT vane PUMP

When it comes to selecting a pumping system, the choice commonly comes down to rotary positive displacement and centrifugal types, as both types can often be used for the same applications.

By virtue of their inherent energy and mechanically efficient designs, positive displacement rotary and sliding vane pumps are perfectly suited to offering operators immediate high value advantages and solutions in fulfilling their energy saving initiatives. In reviewing a list of the most common system characteristics that need to be considered in pumping applications, positive displacement pumps outperform centrifugal pumps is almost all of them.

If you have a relatively low flow and a relatively high-pressure requirement, or if you require the pump to be self-priming, then a vane pump will often be the best solution.

When selecting a rotary vane pump you should, among other things, consider whether it should be:

• Using alternating or direct current
• Oil-sealed or dry

Do you need help choosing the right pump for your industry and needs? Get in touch, our team of knowledgeable experts would be happy to advise you!