In the production and processing of paddy rice, the presence of impurities can significantly impact the quality of rice, reduce the efficiency of equipment, and even lead to equipment malfunctions.
To ensure the quality of the final product and the smooth operation of machinery, effective cleaning methods are crucial. Here, we explore the basic principles and detailed methods of paddy rice cleaning.
1. Screening Method
Screening is one of the most common and widely used cleaning methods. This technique relies on the differences in size and shape between impurities and rice grains, using screens to separate them. Different screening devices can be employed at various stages of the cleaning process:
- Primary Screen: Used to remove large impurities from raw grain, such as hemp ropes, straw, and stones. The primary screen helps improve the efficiency of subsequent cleaning equipment.
- Vibrating Screen: Widely applied to separate large, medium, and small impurities, as well as lightweight impurities. Through vibration, this screen effectively removes various impurities.
- Flat Rotary Screen: Suitable for further separating medium, small, and lightweight impurities, excluding long fibrous impurities.
2. Density Separation Method
The density separation method is based on the relative density differences between rice and impurities. It utilizes the flow of water or air to separate them according to their physical characteristics. Common density separation equipment includes:
- Wet Density Stone Remover: Uses water as a medium to separate impurities from rice based on their different settling rates in water. This method is typically applied during the processing of steamed rice.
- Dry Density Stone Remover: Utilizes air as a medium to remove impurities with higher relative density, such as stones. This enhances the efficiency of the cleaning process.
3. Magnetic Separation Method
Magnetic separation is employed to remove magnetic metal impurities from paddy rice, including items like iron nails and screws. Common magnetic separation devices include:
- CXP Magnetic Separator: Utilizes a magnetic field to attract and separate magnetic metal impurities.
- Permanent Magnetic Drum: Rotates to separate magnetic metal impurities from rice.
The comprehensive application of these cleaning methods efficiently removes various impurities, ensuring the quality of paddy rice and the proper functioning of equipment.
The effectiveness of cleaning directly influences product quality and equipment lifespan, making it essential to choose suitable cleaning methods based on specific production conditions.