The Model 400 double chain buried scraper conveyor features a simple structure and light weight. Classification and Structural Features:(1) The spiral blades of the screw conveyor come in three types: solid spiral surface type, belt spiral surface type, and blade spiral surface type. The solid spiral surface is referred to as the S method, with a spiral pitch of 0.8 times the blade diameter for the GX type. The LS type screw conveyor is suitable for conveying powdered and granular materials. The belt spiral surface, also known as the D method, has a spiral pitch equal to the blade diameter and is suitable for conveying powdered and small lump materials. The blade spiral surface is less commonly used, mainly for conveying highly viscous and compressible materials. During conveying, it simultaneously completes processes such as stirring and mixing, with a spiral pitch approximately 1.2 times the blade diameter. (2) The spiral blades of the screw conveyor come in two rotation directions: left-hand and right-hand. (3) Types of screw conveyors include horizontal fixed screw conveyors and vertical screw conveyors. The horizontal fixed screw conveyor is the most commonly used type. The vertical screw conveyor is used for short-distance lifting of materials, with a conveying height generally not exceeding 8m. It uses a solid surface type spiral blade and requires a horizontal screw feeder to ensure the necessary feed pressure. (4) For the material outlet end of LS and GX type screw conveyors, a 1/2 to 1 loop reverse spiral blade should be installed to prevent powder blockage at the end. (5) The screw conveyor consists of three parts: the conveyor body, the inlet and outlet, and the drive unit. The conveyor body includes the head bearing, tail bearing, hanging bearing, screw, casing, cover plate, and base. The drive unit consists of an electric motor, reducer, coupling, and base.The Model 400 double chain buried scraper conveyor features a simple structure and light weight.