The adoption of multi screw pumps has increased exponentially over the past half-decade, with the consumption volume rising from 146,000 units in 2015 to 202,000 units in 2022.
This rapid rise has been fueled by several factors, including major growth in the industries of end users, such as power generation, food and beverage, and chemical and petrochemicals. Other reasons include the modernization of the water and wastewater industries, the use of these pumps in hydraulic fracturing, and the sustained rise of urbanization and industrialization in the developing world.
In addition to increasing demand, there is also a growing awareness and understanding of the advantages of multi screw pump technology. Indeed, these technologies have benefited from significant improvements, including new designs and the ability to machine within tighter tolerances. Specialized products have also become available with varying levels of performance for a range of specific applications.
The advantages of multi screw pumps
Multi screw pumps provide a range of advantages across their various applications. First, these pumps are distinguished by their energy and operating efficiency, leading to significant reductions in energy cost and cost of maintenance. NETZSCH NOTOS multi screw pumps, for example, lead to 23.3% more efficiency when compared to other pumps on the market.
These pumps can also handle a range of media, including incompressible and highly-viscous products. This includes product that is abrasive, aggressive, corrosive, shear-sensitive, solids laden, low or high viscosity, and lubricating or non-lubricating.
High pressure and leak free, the performance of multi screw pumps is consistently high level. They handle the conveyed product gently and smoothly, also reducing the noise of the process. Because they are entirely made of metal, multi screw pumps can also tolerate temperatures, above 572° Fahrenheit or 300° Celsius.
Multi screw pumps are also hygienic by design, making them ideal for applications in near-sterile environments, such as in the food, beverage, pharmaceutical, and cosmetics industries. These pumps are easy to clean because they are made of stainless steel and are rigorously polished, such that a pumped product cannot stick to the surfaces. This design allows for effective cleaning-in-place (CIP) and sterilization-in-place (SIP) processes.
How multi screw pumps work
The working principle of multi screw pumps is inherent in how their interlocking screws move the product. These pumps function via a drive spindle that transmits torque to multiple rotating, intermeshing spindles. As these screws rotate, the chambers move continuously from the suction side to the pressure side, effectively conveying the product. This operating principle is what drives the smooth and gentle pumping and high performance of screw pumps.
The importance of precision machining in manufacturing multi screw pumps
Precision machining is imperative for modern manufacturing. It ensures effective and smooth production, reduces costs and errors, increases efficiency, and demonstrates top quality. Using the High Efficiency Unique Design (HEUD) concept, NOTOS® multi screw pumps are crafted to achieve precise tolerances and an optimized spindle profile, ensuring long service life and low life cycle costs. Moreover, the pumps have no axial forces acting on the ball bearing, as they are hydraulically balanced. This subjects the bearings to significantly less stress, minimizing the maintenance required for the pump.
Types of multi screw pumps
Multi screw pumps are available in two screw, three screw, and four screw varieties, each is particularly suitable for a specific set of industry applications. These pumps are the preferred choice of industries including oil and gas, maritime and shipping, power generation, process industries, tank farms, and petrochemicals.
A two screw pump, the NOTOS® 2NS has one drive screw that transfers torque to the rotating intermeshing driven screw via a hydrodynamic film. These pumps are ideal for liquids with a range of qualities, from non-abrasive to slightly abrasive, corrosive and non-corrosive, as well as low to highly lubricating mediums. The NOTOS® 2NS is distinguished by its long service life when conveying non-abrasive to slightly abrasive product.
Three screw pumps are designed with two rotating, intermeshing driven screws. Three screw pumps are effective at conveying non-abrasive and non-corrosive product, in addition to liquids with low to medium viscosity. The NOTOS 3NS is a three screw pump that is lightweight and universally applicable with its small footprint, suitable for applications across industry verticals.
Four screw pumps, or geared twin screw pumps, such as the NOTOS 4NS, have two shafts and four screws. Here, torque is transmitted to the driven shaft by way of helical gears. Being hydraulically balanced, this design prevents metal to metal contact between single screws, reducing maintenance by considerable degrees and minimizing turbulence. These pumps are used widely across industries, achieving universal applicability.
Why multi screw pumps are made for modern industry
The positive displacement pump with the highest flow rate, multi screw pumps are ideal for myriad applications across modern industry. The rise of urbanization and industrialization in the developing parts of the world and the increased use of hydraulic fracturing are all factors that account for the increased use of multi screw pumps.
Moreover, these pumps provide immense value in many of the most technologically advanced endeavors in the world, including large scale scientific experiments such as space simulation chambers, gravitational wave detectors, and ultra-high vacuum chambers.
Antonio Castilhos is vice president of national sales for NETZSCH Pumps North America. NETZSCH has been a leading manufacturer of these pumps for decades, having produced these pumps since 1979. Their use of the most advanced technology, combined with their decades-long depth of experience, enables NETZSCH to craft pumps with the highest levels of reliability and durability.
