Before starting the selection of equipment, it is necessary to understand where the walnut will be purchased and what quality. Walnuts can be bought from the population, industrial orchards, and imported from abroad.
Walnuts from private farms will be of different varieties and non-varietal, different sizes, humidity, shell thickness. When buying a walnut from the population, it is important to understand that some part will always be of poor quality – a walnut with a thick shell will come across, which is difficult to process and which does not give a whole kernel. The only way to reduce the amount of such a walnut is through a thorough check upon purchase.
Industrial gardens grow a varietal walnut 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 walnuts from the population, 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 walnut 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 walnut cracking machine. The sorted walnut of the same size is sent to the walnut cracker, pre-set to the size of the walnut. This allows you to reduce to zero possible excessive or insufficient cracking, increase the yield of the whole kernel. For industrial processing, conical walnut crackers are used, they provide the most gentle cracking 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 walnut that, for some reason, has fallen into an incomplete cracking, requires re-cracking or manual cleaning.
– Inspection belt 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 kernel. 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 tape of the inspection table, 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:
- The walnut breaker after cracking machine can be used to process freshly harvested still wet walnuts. Wet walnut is highly elastic and cannot be sorted on a vibrating screen and aspiration, therefore it requires manual or automatic cracking, or drying.
- Lifting conveyors to move the walnut between machines 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.