How do factories shell walnuts?

The traditional method for cracking walnuts involves the use of specialized machines called walnut crackers or shelling machines. These machines employ an array of rotating rollers or blades that gently squeeze the walnuts, breaking the shells without damaging the kernels.

1. Sorting and Pre-Processing: Before the walnuts enter the cracking process, they undergo initial sorting to remove any foreign materials or damaged nuts. This ensures efficient and consistent cracking.

2. Roller System: The walnut cracking machines consist of a series of rollers that are precisely positioned and calibrated. As the walnuts pass through the rollers, pressure is applied to crack the shells. The design of the rollers minimizes the risk of crushing or damaging the kernels.

3. Adjustment of Pressure: The machines allow for adjustments in the pressure applied by the rollers, allowing for optimal cracking based on the nut variety and hardness of the shells.

4. Separating Kernels and Shells: After the walnuts have been cracked, the machine incorporates mechanisms for separating the kernels from the shells. This can be achieved using vibrating screens or air blowers that expel the lightweight shells while collecting the heavier kernels.

Ultrasound Technology

Ultrasound technology has emerged as an innovative method for shelling walnuts. It offers a more precise and efficient cracking process compared to traditional mechanical methods.

1. High-Frequency Soundwaves: Ultrasound shelling utilizes high-frequency sound waves that target and vibrate the walnuts, causing the shells to rupture. The sound waves can be focused or directed to specifically affect the shell without harming the kernel.

2. Separation of Kernels: Once the shells have been broken, the system employs various separation techniques to isolate the kernels from the shell fragments. This can involve screens, air classification, or other sorting mechanisms.

3. Reduced Waste: Ultrasound technology offers reduced waste and greater kernel recovery compared to mechanical cracking methods.

4. Energy-Efficient: Ultrasound shelling is relatively energy-efficient, as it does not require extensive physical force or rotating parts, leading to lower energy consumption.

Both mechanical cracking and ultrasound shelling techniques are employed in the industrial processing of walnuts. The specific choice of method depends on various factors such as the desired production scale, nut variety, and the level of automation required in the manufacturing process.