Many models for accurately predicting the performance of gasket plate heat exchangers were developed in the last decades, grouped in three categories: empirical, semi-analytical or theoretical/numerical, with the view to saving materials and energy through correct design of industrial equipment. This work addresses one such model, namely Lévêque correlation modified by Martin and by Dović, which is promising due to the correct assumption of the flow in sine duct channels and the consideration of energy losses caused by flow reversal at plate edges and the flow path changing when entering the chevron angle. This model was validated by our own experimental data under industrial conditions for vegetable oils processing, both in laminar flow (Re = 8–42) and fully developed turbulent flow (Re = 446–1137). Moreover, in this study, particular values for constants/parameters of the model were determined for the corrugation inclination angle relative to vertical direction equal to 30°. Through statistical analysis, this study demonstrates that this particularized form of the generalized Lévêque correlation can be used with confidence.

In the present paper we have experimentally determined the density, saponification value, iodine value, acid value, peroxide value for four different edible oils: sunflower oil, corn oil, rapeseed oil and peanut oil. Density was determined in the temperature range of 20 o C -50 o C, with a 10 degree step increase. The physicochemical properties of the investigated oils were within the requirements of food domain: saponification value varied from 164.84 to 206.45 mg KOH/g, peroxide value varied from 9.99 to 24.49 mEg O 2 /kg of sample, acid value varied from 0.22 to 3.97 mg KOH/g, iodine value varied from 94.35 to 102.02 g I 2 /100 g sample, and density varied from 0.9031 to 0.9208 g/cm 3 . Based on experimental data, density were correlated with others properties of edible oils. An empirical model was proposed to correlate oil density with iodine value and temperature. The results of the proposed model were compared with a model from literature. The accuracy of the proposed model was very good, the AAD varying in the range of 0.078 % to 0.092 %. The proposed model can be recommended for density of vegetable oils evaluation based on their IV, at different temperatures in the range of 20 o C to 50 o C.

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The major objective of this study is to report physico-chemical properties of sunflower oil samples collected from different stages of the technological process for sunflower oil refining for food industry. The samples of oil were crude oil, washed oil, bleached oil and deodorized oil. The physico-chemical properties of sunflower oil experimentally determined were density, saponification value (SV), iodine value (IV), and acid value (AV). It was found that the density of sunflower oil remains approximately constant over the different stages of the manufacturing flow of cooking oil, except the crude oil. The acid value significantly decreases from crude oil (2.588) to deodorized oil (0.366). The iodine value and saponification value of the different samples of the sunflower oil corresponding to different stages of oil processing varies slightly. The capacity of different models to accurately correlate and/or predict the density of vegetable oil was tested. The density of sunflower oil can be accurately estimated from its SV and IV or with an empirical equation, when density data are available.

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