Seed Drying Via Hydraulic Mechanism, ANSYS Fluent

Description

Seed Drying via Hydraulic Mechanism Project Description

The present problem simulates seed drying via a hydraulic mechanism process using ANSYS Fluent software. Removing moisture from the grain is called drying. The seed drying process should reduce the moisture content of the seeds to a safe moisture level to maintain their viability and stability during storage; otherwise, the seeds may spoil quickly due to mold growth, heating, and increased microbial activity.

In this project, a simple semi-cylindrical chamber is designed for the drying process. Inside the chamber, a set of grains are moderately quickly due spherically, representing wet seeds. The hot airflow from the bottom of the chamber with a temperature of 303.15 K and a speed of 0.15 m.s^-1 moves upwards and exits from the upper part.

The movement of this stream of hot air can carry moisture inside the seeds. Note that, it is not evaporating! It is just a moisture transmission from the seeds region to the surroundings. Therefore, we can call that a hydraulic mechanism of drying. By the way, if you are interested in dying via the evaporation mechanism, you can check the “Grain Drying Device” or “Rice Dryer” projects in which the grains are modeled using the Discrete Phase Model module and evaporation is taken into account.

The present geometry is designed in a 3D model via Design Modeler. The computational zone of the interior is a semi-cylindrical chamber in the middle of which a set of spherical shapes are designed as seeds.

The mesh of the present model has been done via ANSYS Meshing. Mesh is done unstructured, and the number of production cells is equal to 6286496.

Methodology

In this modeling, a combination of air and h₂O is defined in the computational zone of the model, and for this reason, we use the species transport model.

It is also assumed that these spherical seeds are in the form of porous mediums where moisture has penetrated the cavities inside these mediums.

Also, the porosity coefficient of these mediums is equal to 0.418. Note that, the seed zone is wet and has initial moisture which needs to be dried.

Results

After calculation, 2D and 3D contours related to temperature, pressure, and velocity are obtained. The contours show that the moisture or h₂O in the seeds inside the chamber decreases by moving the hot air stream upwards.