Keywords: walnut processing; shell breaking; shell and kernel separation; nut production line
In recent years, with the development of China's economy and the continuous improvement of people's living standards, the demand for walnuts in the domestic market has rapidly increased, which has led to the rapid expansion of walnut plantings. At present, most pecans use artificial shell breaking to remove kernels, which has low productivity, high labor intensity, and high costs. When the shell is broken, there are problems such as a large kernel breaking rate and poor sanitary conditions. To this end, we have developed the first domestic walnut shell breaking and shell kernel separation production line, which better solves these problems. This production line is also suitable for the processing of walnut shells.
1. Status of Pecan Shell Breaker
The cultivar that is commercially cultivated in a large area and is the best-selling in the international market is Pecan. American pecan (also known as pecan) is shown in Figure 1-2. The fruit is oblong or ovate, about 5 cm long, with a thin outer peel and split into 4 petals. It is easy to break the shell and remove the kernel. There is no production of processed goods. In the United States, after grading, washing and shredding, the nuts are mostly used for making candy, bread, ice cream or snacks. The history of processing pecans and edible pecan food abroad is relatively long. Pecans are generally used to make a variety of foods such as pie, salads, cakes, and beverages, such as pecan pie. It is also widely used in the production of pharmaceuticals and cosmetics. Compared with pecan varieties in China, American pecans have thin shells and are easy to take kernels. They are suitable for machining. From 1948, more than 80% of pecans in the United States are sold for shelling. Some large pecans are shelled. Factories process throughout the year, and other small factories or farms process seasonally, most commonly in the fall months. The large pecan processing plant has more than 14 large shelling machines, which can process 150,000 pounds of pecans every day, and can reach 30 million pounds in the first quarter. The storage rooms in these factories are usually equipped with refrigeration facilities. Large factories can have millions of pounds of processed and unprocessed pecans. Hickory from the factory to the factory is basically an automated or semi-automated production line.
1. Grading device with vibrating screen and hair dryer: The pecans are classified according to the fruit diameter.
2. Cleaning equipment: a container with a large volume for cleaning and sterilizing pecans and preparing for pecan peeling.
3. Shelling machine: shell the pecan with its outer shell removed, and separate the inner shell of the pecan from the nut.
4. Breaking device: remove the shell from the nuts.
5. Drying device: remove excess water from nuts.
6. Electric eye impurity removing device: use computer and image processing technology to remove impurities.
7. Conveying device: automatic weighing, packing or manual sorting of nuts on the conveyor by workers. China's pecans are rounder and thicker than the American pecans, making breaking the shell much more difficult. In the process of hand peeling pecans, shell breaking is an important and difficult process. Because the shell of pecans needs to be broken into pieces without breaking, the husk rupture must be appropriate and the nuts must be intact, so as to meet the "hand peeling" requirement.