AERODYNAMIC DRAG OF THE SCREW CHANNEL IN THE CYCLONE-SEPARATOR

A large number of dust collectors differing in their design (geometric) parameters are currently used for purifying process air from dust. Centrifugal dust collectors - cyclones, such as U-38, UCM-38, 4BTSH, OTI, CN, etc., have been widely used for air dedusting in pneumatic transport systems and aspiration systems at grain processing enterprises and at the enterprises of food industry and agriculture. The efficiency of gas purification achievable in these apparatuses is often insignificant in practice. Therefore, a lot of centrifugal gas purification apparatuses are mainly used as the first stage before using more efficient dust and ash collectors. The aero- screw cyclone - separator, whose construction is protected by the patents (1, 2) and based on the screw insert placed between a conic shell and a cylindrical exhaust pipe, enables to achieve the purification degree of process air up to 99.9% on the grain processing products. High efficiency of the aero-screw cyclone is caused by the creation of the swirled helical aero-dispersed flow inside the apparatus with an increasing centrifugal effect due to the variable geometry of the flow-restricting walls. To introduce the aero-screw cyclone at grain processing enterprises, coal industry, power engineering, etc., it is necessary to provide acceptable energy indices during the operation of the given apparatus. The main element which determines the aerodynamic drag of the entire cyclone design is a screw channel. A model is proposed for calculating the aerodynamic drag of the screw channel in the aero-screw cyclone; the influence of the geometric cyclone parameters and of the kinematic and dynamic characteristics of the air flow is analyzed.