International Journal of Vol.5 (No.1). 2023. pp. 16-25 Innovation in Mechanical Engineering & Advanced Materials (IJIMEAM) Published online: April 1, 2023 https://publikasi.mercubuana.ac.id/index.php/ijimeam ISSN: 2477-541X 16 Copyright © 2023. Owned by Author(s). This is an open-access article under CC BY-SA License. COMPARISON OF THE DRYER AIR INLET POSITION ON THE SPRAY DRYER WITH A DOUBLE CONDENSER TO PRODUCE A ROTATING FLOW THROUGHOUT THE DRYING CHAMBER: CFD ANALYSIS Nanang Ruhyat * Department of Mechanical Engineering, Universitas Mercu Buana, Meruya Selatan, Jakarta 11650, INDONESIA Abstract Simulation of the drying air and the spray of liquid in the spray dryer chamber with Discrete Phase Material (DPM) and Discrete Random Walk (DRW) was presented in this study using CFD methods to analyze the drying liquid. The main problem in spray drying is the adhesion of the material to the drying chamber walls, which causes uneven drying material. This adhesion can slow down the drying process and reduce productivity. The design of the drying air inlet into the drying chamber becomes essential to research. Variations in the position of the drying air inlet into the drying chamber are carried out in the 3D spray dryer room to see the mechanism of the centrifugal velocity of the drying airflow, which can improve uniform mixing with flow resistance due to friction with small walls and the drying air velocity. This phenomenon is impossible to observe in experiments. A geometric model consisting of 1,054,000 hexa-mesh elements at the area around the nozzle, the top spot of the chamber and the remaining area covered with a tetrahedral mesh, was determined to predict velocity, temperature, and fluid flow behavior. The first position, the dryer air inlet, is at an angle from the diameter of the spray drying chamber. The second position is in the middle of the diameter of the drying chamber. The position of the first inlet produces a more even temperature contour with a more tangential velocity due to the small frictional resistance with the walls. At the same time, the second position is not recommended because the flow leads to one side of the wall and creates sticking and even material buildup. A double-heated condenser can dry air at moderate temperatures, and it is a very effective drying product — positioning the dryer air inlet into the drying chamber, achieving the economical production of high-quality products. Keywords: Dry Air Inlet, Drying Process Material, Discrete Random Walk, CFD, Spray-Dryer *Corresponding author: Tel. +62 21 5840815 Ext. 5200 E-mail address: nanang.ruhyat@mercubuana.ac.id DOI: 10.22441/ijimeam.v5i1.21605 1. Introduction Spray-dryers have been known since 1870. Spray-dryers are generally used in the pharmaceutical, chemical, and food industries for drying[1]. The dryer changes the liquid phase of the material to be dried with drying air[2] into a vapor phase and then removes water vapor in the liquid material to become dry powder[3]. Dryers can reduce or eliminate microbial growth on the material by reducing the water content[4]. Several things that the researcher did before in determining dryer product quality as inlet drying temperature[5–7], feed flow rate[8], ambient temperature and relative humidity[9], Feed Concentrated [9], Atomization speed[6, 10–12], Inlet air velocity and pressure operation as well as outlet temperature[13], and droplet diameter[14]. In addition to the seventh thing above, it can also be done by constructing the drying air inlet hole connected to the drying chamber to increase the effect of swirling flow in the material drying chamber. The practical structure of the air-liquid junction mechanism, which is more efficient in producing dry powder, is urgently needed and has yet to be studied. Measurement of airflow, temperature, particle size, and humidity in the drying chamber is challenging and expensive to perform in large-scale dryers. Previously, researchers had conducted experiments with double condensers from the refrigeration system[3]. The humidity of the air that will enter the heater room has been successfully reduced to increase the quantity of the product. Understanding particle collisions in the drying chamber is essential to study because it affects the quality of the final product. A 3D CFD model of the agglomeration of