Pneumatic polishing of rice in a horizontal abrasive pipe: A new approach in rice polishing

• A new type of pneumatic rice polisher has been developed.
• The developed polishing system does not have any moving parts
• It gives uniform polishing of rice with less breakage of kernels
• At same polishing level, system gives less broken than commercial abrasive polisher

A pneumatic rice polishing system, based on jet-polishing technique of metal surface, has been developed to minimize broken. This consists of 5 cm diameter polythene pipe; inner surface is lined with hard abrasive material, a blower and a collection system, and no moving part. Brown rice and air are fed through 180° scroll and flow through abrasive pipe. The system used 28.2 m s− 1 airflow, 0.45 kg min− 1 feed rate and different pipe lengths (1.0–4.0 m; interval 0.5 m). Degree of polish and broken varied with both pipe length (L) and number of passes (N; 5–50). System showed uniform polishing, and degree of polish (Dp) varied from 3.72% (1 m) to 9.97% (4 m), and linearly with N. 8.52% broken was obtained (4 m pipe) while laboratory abrasive polisher yielded 20% at equal Dp level. Effects of N and L and their interactions were found significant (p < 0.05) on Dp.Industrial relevance
• The technology will yield higher head rice and less breakage of kernels
• System is very simple with no moving part
• Maintenance and operating cost will be much less.