Design and Testing of Water Jet-Based Fresh Lotus Seed Peeling Machine

Abstract

Highlights Lotus seed coats are often peeled using water jets, which has not been studied in-depth. A water jet-based lotus seed peeling system is proposed and investigated in detail. Response surface method experiment was used to enhance peeling-machine performance. Proposed system performs well in terms of cost, stability, and percentage of seed peeled and damaged. Abstract. Lotus seed coats are often peeled using water jets. However, currently, existing fresh lotus seed peeling machines could process lotus seeds only if their size differences are small. Due to a lack of research on water jet operation parameters, the peeling process is often associated with a low percentage of seed peeled (PSP) and a high percentage of seed damage (PSD). A new type of water jet-based fresh lotus seed peeling machine was designed and tested to solve the aforementioned problems. Three-factor, three-level response surface method (RSM) was used in experiments to enhance peeling-machine performance, and quadratic polynomial regression equations were obtained via analysis of the experimental data. Results show that these independent variables had significant effects on PSP and PSD: water jet pressure (X1), water jet angle (X2), and processing speed (X3). Specifically, X1 and X2 had an interactive effect on PSD, whereas X1 and X3 both had a strong interactive effect on PSP and PSD. The optimal parameters were a water jet pressure of 0.60 MPa, water jet angle of 20°, and processing speed of 62 rpm, leading to predicted PSP and PSD of 93.13% and 1.65%, respectively (similar to the validation experimental PSP and PSD of 93.89% and 1.76%, respectively); thus, proving the accuracy of the RSM model. In general, the proposed peeling machine provided a high machine capacity (19.65 kg/h), a high percentage of seed peeled, and a low percentage of seed damaged, and all performance indices fulfilled the requirements for use. Keywords: Lotus seed, Parameter optimization, Peeling, Water jet.