Improving the drying process of fruits using convective method

Development of science and technology Scientific and technical journal №1/2026 24 Texnika, texnologiya va jihozlar The drying process is studied using a fullfactorial experimental method to determine the optimal regimes for drying fruits using the rollingpallet device. Investigation under optimal conditions is carried out using the second-order rotatable composite method. To increase the volume of dried product production, measures are being implemented to improve production technologies, process raw materials comprehensively, and re-equip network enterprises with modern technologies and highly efficient equipment. The general view of the proposed continuous convective drying device with tilting trays is shown in Figure1. The device operates as follows: the raw material is loaded into the system through the raw material feeding mechanism (2). The hot air flow enters the vertical drying chamber casing (1) via the inlet duct (10) and is supplied to the lower side of the horizontal trays, which are positioned at the lowest end at an inclination angle of 5°. The direction of the raw material and the drying agent in the tilting tray dryer is shown in Figure 2, while the arrangement of the fruits on the trays is illustrated in Figure 3. The trays (3) are installed consecutively at alternating angles (5° and 175°). This arrangement ensures that the drying agent moves in a “zigzag” pattern along the height of the chamber, thereby drying the product placed on the trays. The product on the lowest tray exiting the device comes into contact with the fresh drying agent supplied to the chamber. The product and the drying agent move in opposite directions. The drying agent, having high temperature, low relative humidity, and high enthalpy, maximizes the removal of moisture from the product. The used air passes between the trays and is discharged into the atmosphere through the duct (11), or it can be mixed with fresh air entering through the shutter (9), heated to the required temperature in the heater (4), and returned to the drying chamber via the circulation pipe (6) with the help of the fan (5). To maintain a uniform flow of the drying agent and prevent accumulation in the chamber, a cover (7) of a conveyor shape is provided. The bottom (8) is also of a conveyor shape, where the dried product is initially collected and, under the influence of gravity, is transferred from the device to the tray via the weight doser (15). The weight doser opens when the product reaches a Figure 1. General view of the convective dryer Figure 2. Arrangement of the rotating trays “Fan va texnologiyalar taraqqiyoti” Ilmiy-texnikaviy jurnal №1/2026 25 Technique, technology and equipment predetermined weight and remains closed otherwise, preventing heat loss. The device is installed on a support frame (12). The process ensures uniform distribution of airflow over each tray and allows the product to transfer from one tray to the next in a different position relative to its initial state. This increases the drying intensity and ensures uniform drying of the product. The distance between the trays is selected so that any product that might stick to the upper tray is dislodged by the rotation of the lower tray [3]. Inside the chamber, there are several rows of horizontally rotating trays, each supported on both sides by bearings. All the horizontal trays are mounted on a single shaft and move in parallel. The shaft is driven by a chain transmission (13). Figure 3. Movement of the drying agent Figure 4. Arrangement of fruits on the tilting trays. In the proposed device, the drying process is organized continuously. The rotation of the raw material and the complete interaction of the product with the trays ensure uniform drying of the product surface. This design minimizes energy consumption, increases the operational efficiency of the device, and enables the production of high-quality dried products. Development of science and technology Scientific and technical journal №1/2026 26