Research of the process of vegetable oil extracting under the influence of a high frequency wave field

Abstract

Research in a laboratory press equipped with an ultrasonic vibrator was performed to study the nature of a high frequency wave field influence on the process of vegetable oil extracting from safflower seeds. The initial moisture content of safflower seeds, the rotational speed of the press screw, the frequency and amplitude of ultrasonic vibrations have the greatest influence on the oil yield and the cake residual oil content. The analysis of the dependences obtained showed that the parameters of the safflower seed pressing process, the values of which could be varied during the experiments, affect the oil yield identically, namely, with an increase in the rotational speed of the press screw, the oil yield decreases and, consequently, the cake oil content increases. It was found out that moisture content raising increases the oil yield and reduces the residual oil content. Moreover, the most rational value of moisture content in terms of absolutely dry matter is 8.7…11.2%. It was revealed that an increase in the pressure given to the product in the press occurs with a decrease in the effective viscosity inside the surface layer of the mass being pressed due to ultrasonic vibrations imposition. The following parameters should be focused on as rational parameters for safflower seeds pressing providing the minimum residual oil content in the cake: the ultrasonic waves frequency is 22…28 kHz, the amplitude is more than 40 • 10−3 m and the pressure value in the press is from 12…13 MPa. These values obviously depend directly on the grain behavior and its movement in the press during exposure to high-frequency ultrasonic vibrations.

Mathematical model of the influence of geometric parameters of the shaft on the productivity of the screw press

“…The primary parameters ensuring the efficiency of the oil extraction process using such presses are the fullest oil extraction with minimal energy consumption [6]. Achieving these conditions is possible by refining existing designs of screw oil presses intended for using a specific type of oil-containing raw material and selecting optimal operating modes for them [7].…”

Influence of Drying, Pressing, and Antioxidants on Yield and Oxidative Stability of Cold Pressed Oils

“…However, when pressing saffron with a moisture content of 4.87 % and oil content of 22.93 %, the press became clogged and stopped working. Ovsyannikov et al 49 reported that, at moisture content less than 8.7 %, the cellular structure of the membrane destroyed by the screw, adsorbed a certain amount of oil, which could not be separated at appropriate pressures. By pressing safflower with a moisture content of 8.37 % at N = 11 mm, F = 30 Hz, and T = 90 °C, a higher amount of cold pressed oil (225 ml) was produced than with the 16-mm nozzle size, which, as with the other two oilseeds, could be explained by increase in pressure.…”

“…However, according to Ergönül and Özbek 50 , the optimum safflower seed moisture content for cold pressing is 12 %. Ovsyannikov et al 49 pressed safflower seeds with moisture content of 4.2-16.3 %, and stated that moisture content of the initial seeds had a significant effect on the oil yield; as the moisture content increased, the oil yield increased as well, while the residual oil content of the cake decreased.…”