For more than 40 years, Valencia-based Maquienvas has been specializing in machinery and equipment for the packaging industry. Alongside capping machines, labeling systems and complete packaging lines, their wide range of products includes filling machines for different challenging fluids such as fertilizers. To meet highest product standards and achieve maximum precision in dosing these products, Maquienvas initially utilized electromagnetic and mass flow meters.
The challenge of reliably dosing varying fertilizer types
However, electromagnetic and mass flow meters are not ideally designed for this application. The corrosive nature of ingredients like potassium hydroxide and phosphoric acid contained in different fertilizers led to equipment degradation. The requirement of the product storage tank to be pressurized further increased the risk of leakage as well as maintenance efforts. As a result, certain components of the dosage system had to be replaced frequently, and overall maintenance costs were relatively high.
Varying physical properties of the fluids, some containing organic particles of up to 1 mm, posed additional hurdles in maintaining consistent flow rates while dosing the fertilizers. These difficulties propelled Maquienvas to seek a more effective and efficient approach – prompting them to turn to NETZSCH, renowned for their innovative fluid management solutions.
“For this application, we recommended PERIPRO® peristaltic pumps, because they are very reliable, compact, as well as easy to install and maintain,” Borja Tarin, Area Sales Manager at NETZSCH. “They also allow to precisely control the flow rate – no matter the corrosive or organic nature of the fluids.” In 2023, Maquienvas thus installed the first two PERIPRO® C10/2.7 hose pumps in their fertilizer dosage system.
Maquienvas‘ fertilizer dosing machine features two filling stations, each operated by a PERIPRO® C10/2.7 peristaltic pump.
Reducing maintenance while ensuring a continuous flow rate
As the name suggests, PERIPRO® peristaltic pumps operate based on the principle of peristalsis, mimicking the natural movement found in biological systems such as the human gastrointestinal tract. Their main characteristic is a flexible hose installed within the pump housing. A pair of large, robust and resistant rollers rotating on a rotor systematically compresses and releases the hose, creating a seal. As the rollers rotate, they move the pinch-off point along the hose, thus pushing the pumped product ahead of them. This movement combined with the elasticity of the hose material also generates a suction vacuum behind the roller to draw more fluid into the hose.
The resulting continuous flow allows for the highly precise dosing demanded by Maquienvas – even when the conveyed fertilizers contain solid particles. To prevent degradation of organic components as well as potential foaming, the fluids are pumped at a steady 37 revolutions per minute at a pressure of 0.5 bar, which results in a flow rate of 1,941 l/h at 50 Hz. This is well within the performance range of the PERIPRO® C10/2.7 model, which allows for a flow rate of up to 3,700 l/h at a pressure of up to 10 bar.
Minimizing points of contact with the fluid
Due to the pump design, the fluid does not come into contact with the internal parts of the pump, as all of the product flows inside the peristaltic hose. “This minimizes the risks of contamination and corrosion caused by chemicals such as potassium hydroxide and phosphoric acid”, adds Tarin. As sole point of contact with the fluid, the hose made of EPDM has already proven its durability: it has not required replacement since the initial installation at Maquienvas in December 2023. Additionally, the straightforward construction of the PERIPRO® makes it easy to maintain, as there are no mechanical seals, valves, or other intricate components that are prone to wear and tear. The system also requires very low amounts of lubricant, further simplifying maintenance and improving longevity.
To precisely control the flow rates in the batch dosing system, Maquienvas installed an encoder between the reducer and the motor. For the repetitive dosing process metering a fixed product volume, the encoder divides each revolution into a specific number of pulses. Given the constant volumetric capacity per revolution, this ensures the exact amount of fluid poured into each jerrycan and bottle – which the operator defines via an electrical control panel. “For a specific volume, you need a certain number of revolutions. Therefore, simply by counting revolutions, you will achieve the final volume to be dosed”, further explains Tarin.
Proven excellence paves the road for further collaboration
The collaboration between Maquienvas and NETZSCH underscores the importance of precise, reliable technology in fertilizer dosing applications. For Maquienvas, adopting the PERIPRO® peristaltic pump provided a robust and efficient solution for a rather challenging type of application. On top of that, NETZSCH has proven to be a reliable partner, providing excellent service, technical expertise, and follow-up support. The successful project has already prompted Maquienvas to invest in identical PERIPRO® pumps for three more systems – with the most recent order only being placed in 2025.
