Rotary lobe pump advantages and disadvantages vs EODD pumps

What is the purpose of a rotary lobe pump?

Rotary lobe pumps are common in the manufacturing industry as a gentle, effective solution to handle a wide range of viscosities across various industries. These pumps do, however, have limited compatibility with fluids containing chemistry and are susceptible to damage because of their complex design, which can lead to hazardous situations and high maintenance costs. Electric diaphragm pumps address these common issues.

Advantages of rotary lobe pumps

• High efficiency
  Rotary lobe pumps are designed to provide a smooth and consistent flow for efficient fluid transfer, which makes them a good choice for industries where energy consumption is important. Even so, Graco’s electric diaphragm pump can cut energy usage and costs by up to 80%, providing an even lower cost.
• Versatile
  Rotary lobe pumps are able to handle a wide variety of liquids, including high viscosity materials. This makes them a common choices for industries such as food processing, wastewater treatment, chemical processing, and other highly viscous fluids applications.

Disadvantages of rotary lobe pumps

• Reduced lift with thin liquids
  Extra care is needed when selecting a rotary lobe pump for pumping thin non-lubricating liquids. All pumps have a small amount of liquid that goes from the discharge point back to suction. This is called slip, and varies according to liquid viscosity and differential pressure. Some rotary lobe pumps can be used with thin liquids, and most manufacturers offer several options to handle the low lubricity and viscosity typically associated with thin liquids, but it adds more complexity to the pump selection procedure and maintenance processes after installation compared to using electric diaphragm pumps.
• High maintenance costs
  Rotary lobe pumps have a number of rotating parts that need precision tolerances, which makes them more expensive to manufacture and maintain. Furthermore, the rotating parts utilise expensive and sensitive seals that can easily lead to leaks if the pump is pushed beyond its performance limits and is not properly cleaned or maintained according to the service intervals. The QUANTM electric pump’s efficient and seal-less design ensures that it is not sensitive to wear and erosion and is easy to repair.
• High investment costs
  Rotary lobe pumps are designed with rotors, which are synced by a separate gear in the back of the pump. This increases manufacturing cost. Add to this the two relatively expensive mechanical seals and it is not surprising that investment costs are high in comparison with other pump technologies on the market.
• Unsatisfactory solution for abrasives
  The rotary lobe pump’s intricate and sensitive design is not ideal for abrasives, which are bound to damage the system and its expensive parts. The pump’s lifecycle can be slightly extended by reducing pump speed and using hardened parts in key wear areas, but electric diaphragm pumps are clearly a better fit when you need higher flow rates and long-lasting durability.
• Cannot be allowed to run dry for extended periods of time
  A rotary lobe pump cannot run dry without destroying its expensive stators and rotors due to the pumped fluid acting as a lubricator between the rotor and stator. QUANTM electric pumps can run dry without causing any damage to the system, avoiding expensive repairs.

Common applications of rotary lobe pumps

• Food and beverage industry
  Due to the gentle pumping action and sanitary design, rotary lobe pumps are commonly used in the food and beverage processing industry for various applications. These applications include transferring liquids, handling viscous products like sauces and creams, and pumping delicate food items without damaging their texture or integrity
• Pulp and paper industry
  Common applications for rotary lobe pumps in the pulp and paper industry include metering and dosing chemicals, transferring adhesives and coatings, and transporting various high-viscosity fluids. It is crucial to transfer slurries without damaging the pump or material. Air pockets in the system can impact its efficiency and may damage product.
• Pharmaceutical industry
  The gentle product handling and precise flow of rotary lobe pumps makes them a common choice for use in various pharmaceutical manufacturing processes. These applications require safe transfer of sensitive materials, accurate metering of ingredients, and a consistent temperature to not impact the material being transferred.

Electric diaphragm pumps (EODD) vs rotary lobe pumps

Compared to a traditional rotary lobe pump, the QUANTM EODD provides much more flexibility and a significantly lower maintenance cost. Take a look at the benefits: