Design of a vertical Loss-in-Weight feeder prototype with experimental proof of concept validation

Pharm Dev Technol. 2021 Jun;26(5):559-575. doi: 10.1080/10837450.2021.1901915. Epub 2021 Apr 19.

Abstract

Loss-in-Weights (LiW) feeders are commonly oriented in a horizontal way. In this work, an experimental proof of concept, including mechanical and electrical design, construction, and operation, of a vertical LiW feeder prototype is performed. In a systematic design process, based on functional design specifications, the semi-automated vertical LiW feeder for dosing a wide range of powders, especially cohesive ones, is developed. The new dosing machine is assessed with regard to a number of key features such as high dosing accuracy, first-in-first-out powder discharge, easily interchange of the powder container, and flexibility in controlling the speed of the auger and stirrer motors independently. An experimental sensitivity analysis to study the functionality of the dosing machine and to investigate the weight variability of the weighing platform, i.e. mass flow rate, and quantity of dosed mass, is carried out. The results of the sensitivity analysis and the powder dosing tests of five diverse powders using different auger and stirrer geometries verified the proof of concept prototype.HighlightsA systematic design approach for validating a proof of concept of a vertical loss in weight feeder is appliedA full mechanical CAD design and implementation along with electric installation and software programming are executedSensitivity analysis approach is performed to validate the functionality of the semi-automated machine and successfully dispense dissimilar powders tested with different process parametersThe machine is characterized with a number of key features: first-in-first-out powder discharge, high dosing accuracy, flexible and modular concept design, flexibility in controlling the speed of the auger and the stirrer independently, lightweight and user-friendly design.

Keywords: Loss-in-Weight feeder; Machine design; auger dosing; mass flow rate; powder dosing; proof of concept.

Publication types

  • Comparative Study
  • Validation Study

MeSH terms

  • Drug Compounding / instrumentation
  • Drug Compounding / methods*
  • Equipment Design
  • Excipients / chemistry*
  • Powders
  • Proof of Concept Study
  • Technology, Pharmaceutical / instrumentation
  • Technology, Pharmaceutical / methods*

Substances

  • Excipients
  • Powders