Paper—Experimental Assessment of Hydrocyclones with two Inlet (Feed) Gates Experimental Assessment of Hydrocyclones with two Inlet (Feed) Gates https://doi.org/10.3991/ijes.v6i3.9409 Ebrahim Alamatian (*) , Ayda Nasiri-Kalat Khavaran Institute of Higher Education, Mashhad, Iran e.alamatian@profs.khi.ac.ir Abstract—Hydrocyclone is a device to separate sediments in the water Gravel and sand particles are separated based on the specific weight of the sus- pended particles in the water by the ratio of their centripetal force to fluid re- sistance. Generally, hydrocyclone includes inlet (feed) and outlet flow gates. In this paper, one of the hydrocyclone, which is in the Wastewater Treatment Plant of Mashhad, has been investigated with respect to rising of the number of inlet flow gates. In other words, water enters to hydrocyclone with two inlets, which have made by welding and cutting operations. Results of this research show that the device efficiency has been enhanced 77 percent in sediment removal and the shear limit has been decreased 15 percent by increasing the number of the inlet gates. Assessments indicate the local temperature is not effective in the rate of particle removal in hydrocyclone. Keywords—Hydrocyclone, Shear limit, Inlet gate, Efficiency, Pressure drop 1 Introduction The existence of particles such as sand in drinking water has caused consumer's dis- satisfaction, water pollution and an increase in chlorine use. Moreover, the pumps and water network systems have been eroded and the washing cost of the reservoir and water network supply have to be increased by these particles. Entering the gravel and particles into the water network supply declines water quality and settles into pipes, then the pipe would be destroyed and the pipe diameter would be increased as well. Furthermore, the valves and consumption measurement tools have damaged due to the particles. One of the straightforward and essential tools, in order to access to desirable water quality, is hydrocyclone in wells output and water network supply entrance due to high efficiency and low maintenance expenditures. According to Figure 1, hydrocyclone consists of the main cylinder body, which has a central pipe named vortex finder conduct. The underside of the cylinder connects to a cone that ends part of it is called a spigot. In addition, an inlet pipe (feed) connects to the top part of the cylinder. Entry of tangential flow from the pipe causes rotation and centrifugal force. Primary and secondary vortexes are created by flow rotation and cen- trifugal force. Primary vortex takes roughing and suspended particles to the hydrocy- clone wall and then moves towards spigot. Afterward, the second vortex leads to light 86 http://www.i-jes.org