Before starting the selection of equipment, it is necessary to understand where the walnut will be purchased and what quality. Walnuts can be purchased from the public, industrial orchards, and imported from abroad.
Walnuts from the population will be of different varieties and non-varietal, different sizes, humidity, shell thickness. When buying a nut from the population, it is important to understand that some part will always be of poor quality - a greedy nut will come across, which is difficult to process and which does not give a whole kernel. The only way to reduce the amount of greedy nut is through careful checking when purchasing.
Industrial gardens grow a varietal nut that has a thin shell. The same walnut is imported from countries where there are many industrial orchards of varietal walnut (China, USA, Turkey, etc.).
The processing of varietal and non-varietal walnuts is different and requires different equipment.
When processing large volumes of local walnuts from the public, the emphasis is on automation. Often, processors are guided not by obtaining a whole kernel, but by volumes, respectively, equipment is selected that cracks the nut as much as possible.
When processing high-quality walnuts, the entrepreneur expects to receive whole kernels, since a lot of labor and finances are invested in growing a garden.
For the processing of high-quality walnuts, a set of equipment is required:
- Calibrator for sorting walnuts in shell by size.
- Industrial nutcracker. The sorted walnut of the same size is sent to the walnut splitter, pre-set to the size of the walnut. This makes it possible to reduce to zero the possible splitting and undershotting, to increase the yield of the whole kernel. For industrial processing, only cone nut crackers are used, they provide the most gentle split and preserve the integrity of the kernel.
- Vibrating sieve with aspiration. To minimize damage to the kernel during transfers and processing, an installation is used that combines two functions at once - separating the kernel from the shell and sorting the kernel into fractions. As a result of the operation of the vibrating sieve with aspiration, you get a sorted kernel into fractions of 1/2, 1/4, 1/8. A part of a nut that, for some reason, has fallen into an incomplete splitting, requires re-splitting or manual cleaning.
- Inspection table. The kernel sorted on the hardware needs visual quality control. The equipment cannot provide 100% sorting, so random pieces of shell or partition can get into the mixture with the core. Also, the equipment does not sort by color, which means that darkened or dried kernels will fall into the total mass. Quality control takes place on the inspection table tape, where the staff selects from the total mass of the kernel what should not fall into the package.
Additional equipment for the processing of high-quality walnuts:
- Walnut breaker after industrial nutcracker can be used to process freshly harvested still wet nuts. Wet walnut is highly elastic and cannot be sorted on a vibrating screen and aspiration, therefore it requires manual or automatic splitting, or drying.
- Elevating conveyors to move the nut between plants and process continuity.
- A color sorter for sorting the kernel by color and / or separating the kernel from the shell is used for large volumes of processing.