Maximum precision with Rotovalve Plus for transfer and dosing of various consistencies of polyamide from a tipping hopper system to containers

Maximum precision with Rotovalve Plus for transfer and dosing of various consistencies of polyamide from a tipping hopper system to containers

The case of a multinational company with a subsidiary in Germany, specialized in the design and production of equipment for powder handling in the chemical, food, polymer, and metallurgical sectors.

The Case: the client contacted us to find a solution that would allow for speedy feeding and precise dosing of +/- 100 g of different types of polyamide present on their site, with varying particle sizes, densities, and flow characteristics. The client’s application involves a tipping hopper that feeds the product in transit into a discharge cone; subsequently, it’s discharged through the rotary valve into various containers. The batch to be transferred ranges from 30 to 300 kg, with a required time interval between 1 and 10 minutes and a precision of +/- 100 g.

Issue: the products in transit are not uniform but consist of a series of polyamides with varying densities and flow properties. The client’s initial challenge included:

  • Handling an uncommon and not easily manageable parallelepiped-shaped container.
  • Dealing with transit products that vary in terms of density and flow properties.
  • Managing a high flow rate that needed to be transferred in a short time.
  • Demand for high precision of +/- 100 g.

Analysis Method: the technical feasibility was assessed by considering valve models capable of accurately discharging and dosing the mentioned transit products, while adhering to the client’s requested timelines and accommodating different densities. Several theoretical calculations were performed regarding the required flow rate, taking into account various variables such as bulk density ranging between 300 and 480 kg/m³. Finally, to validate the estimates, the client was proposed to conduct tests at Sterivalves using the Rotovalve Plus. The tests measured product density, discharge accuracy, and maximum flow rate. The test results confirmed the predictions from theoretical calculations. The test was conducted using the product with the poorest flow characteristics and lowest density.

Solution: the proposed model is a Rotovalve Plus DN 200 with 8 lobes, equipped with Tri-Clamp 6″ BS 4825-3 connections, an EPDM seal, and an electric gear motor. The valve seamlessly integrates with the client’s components due to its compact, lightweight, and essential design. Additionally, the model is suitable for WIP/CIP/SIP cleaning processes with hot water at 50-85°C or steam at 2 barg (130°C).

Conclusion: the utilization of Rotovalve Plus enabled:

  • Ensuring the high precision demanded by the client.
  • Rapid and seamless discharge of substantial product quantities.
  • Managing products with diverse characteristics (density, particle size, flow properties).
  • Seamless integration with the existing system due to its specialized design

Client Feedback: “We are extremely pleased with the test results, far beyond our expectations. The tests allowed us to validate the process. We believe that, in our case, the opportunity to directly test the product at Sterivalves was crucial in resolving doubts about managing a complex system. The Rotovalve Plus proved to be not only a versatile solution but also an astonishing response to an extraordinary technical challenge.”