Rice processing is the core function of a rice mill, transforming raw paddy into marketable rice. This involves multiple stages to ensure high-quality output that meets customer expectations.
a. Cleaning
- Purpose: Remove impurities such as dust, straw, stones, and other foreign materials from raw paddy to ensure clean, high-quality rice.
- Implementation:
- Use modern cleaning machines like vibratory pre-cleaners, destoners, and magnetic separators to efficiently remove impurities.
- Install multi-stage cleaning systems to handle different types of contaminants (e.g., large debris, fine dust, and metal particles).
b. Husking/Dehusking
- Purpose: Remove the outer husk from paddy to produce brown rice, a critical step in milling.
- Implementation:
- Use pneumatic or rubber-roll huskers for gentle and efficient husk removal, minimizing grain breakage.
- Adjust husking machines to accommodate different paddy varieties (e.g., long-grain vs. short-grain).
- Integrate aspiration systems to separate husks from brown rice effectively.
c. Whitening and Polishing
- Purpose: Remove the bran layer from brown rice to produce white rice and polish it for a shiny, marketable appearance.
- Implementation:
- Use friction or abrasive whitening machines to remove bran layers, followed by polishing machines to enhance appearance.
- Offer customizable polishing levels (e.g., light polish for nutritional retention, heavy polish for premium white rice).
d. Grading and Sorting
- Purpose: Sort rice by size, quality, and type to meet specific market requirements and ensure uniformity.
- Implementation:
- Use grading machines like rotary sifters or vibratory graders to separate rice into categories (e.g., head rice, broken rice, small grains).
- Employ color sorters to remove discolored or defective grains for premium products.
- Integrate automated systems for high-speed, accurate sorting
e. Parboiling and Drying
- Purpose: Parboil paddy to enhance nutritional value and shelf life, and dry it to optimal moisture levels for milling and storage.
- Implementation:
- Set up parboiling units with soaking tanks, steamers, and dryers to partially cook paddy before milling.
- Use modern dryers (e.g., LSU dryers or fluidized bed dryers) to reduce moisture content to 12-14% for safe milling and storage.
- Automate temperature and moisture control to ensure uniform parboiling and drying.