In continuation with the cashew nut production, steps: Cooling and Ventilation!
In this new post we will explain how the process of cooling, decortication and ventilation of the cashew nut kernel occurs.
In the previous post we stopped at the part where the cashew nuts were being centrifuged. After this phase is completed, the cashew nuts that are still at high temperature are resting in a cooling silo for 1:30 to 2:00 hours, where they will be subjected to forced ventilation to reduce the temperature to approximately 44°C, depending on the cashew nut type. When the cooling time is insufficient, the cashew nut become too breakable to the point of compromising the kernel, causing a high rate of breakage. At the other hand, when the cashew nuts receive a prolonged cooling, they become " rubbery " (flexible) and their cut is compromised.
After this part is finished, the cashew nut proceed to the next stage, the decortication, which is where the cutting or opening of the cashew nuts occurs, thus separating the kernel from the shell. The mechanical process of decortication is done by shock or impact of the cashew nut on a disc that throws it in high rotation against a target plate, and for this process to occur more efficiently we at Onvit have 7 decorticators with different powers, thus mitigating as much as possible the breakage of the kernel.
After the decortication, the kernel goes to the ventilation, since a large amount of kernels remain attached to the shell, the cashew nuts continue their journey through a circuit of fans where, by projection against fixed surfaces, the kernel is separated from the shell, with the supporting action of vibrating sieves. The semi-open nuts return to the cutting mechanism to complete this stage.
The shells and shelled kernels proceed to a vibrating sieve. The shells go to the storage silo, and the pieced kernels pass through two more ventilators. In one ventilator it comes out more kernels in pieces, and in the other more shells. After this stage, these products pass through another ventilator, where the separation of the shell, testa and pieced kernels with shell takes place. The return ( kernels plus shell ) goes back to the decorticator. The process is then continued for unshelled kernels. In the case of the shells, they go to a storage silo.
Thus, after having learned about these three processes, we can observe how one of the main stages in the transformation of cashew nuts into cashew nut kernels occurs, the decortication or more commonly known as cutting. In the next post we will continue addressing the next steps of our cashew nut manufacturing process.