Screw conveyor is divided from the perspective of the displacement direction of conveyed materials, and screw conveyor is divided into two types: horizontal screw conveyor and vertical screw conveyor.
Screw conveyor made of high-strength plastic according to the conveyor chain, also known as food screw conveyor, screw elevator, is mainly suitable for conveying large products. Such as cartons, turnover boxes, bottled water, etc.
According to the different characteristics and requirements and structure of the conveyed materials, screw conveyors include horizontal screw conveyor, vertical screw conveyor, bendable screw conveyor, spiral pipe (roller conveyor) conveyor.
Vertical screw conveyor
The speed of the spiral body of the vertical screw conveyor is higher than that of the ordinary screw conveyor, and the added material has a friction force between the casing under the action of centrifugal force, which prevents the material from rotating with the spiral blades and overcomes the gravity of the material falling, so as to realize the vertical conveying of the material. The conveying capacity of the machine is small, the conveying height is small, the speed is high, and the energy consumption is large. It is especially suitable for conveying powdery materials with good fluidity, mainly used to lift materials, and the lifting height is generally not more than 8 meters.
Horizontal screw conveyor
When the material is added to the fixed groove, due to the gravity of the material and the friction between it and the groove, the material accumulated in the lower part of the groove does not rotate with the spiral, but only moves forward under the push of the rotating spiral blades, just like the non-rotating nut along the rotating screw for translational movement, to achieve the purpose of conveying materials. The machine is convenient for multi-point loading and unloading, and the functions of mixing, stirring or cooling can be completed at the same time during the conveying process. Sensitive to overload, easy to block; There is crushing loss for materials, and the structure of horizontal screw conveyor is simple, which is convenient for installation and maintenance and fault handling. It is suitable for horizontal or slightly inclined (below 20º) continuous and uniform conveying of loose materials, the working environment temperature is -20-+40 °C, and the temperature of the conveyed materials is -20-+80 °C. Its speed is lower than that of the vertical conveyor, mainly used to transport materials horizontally or at small inclination angles, and the conveying distance is generally not more than 70 meters.
Spiral pipe (roller conveyor) conveyor
The spiral pipe conveyor is welded with continuous spiral blades in a cylindrical casing, and the casing rotates with the spiral blades. The added material rotates and is lifted together randomly by the centrifugal force and friction, and then slides down the spiral surface under the action of gravity of the material, so that the material rotates with the spiral tube to realize the forward movement of the material, just like the non-rotating screw along the rotating nut for translational movement, to achieve the purpose of conveying materials.
The machine has low energy consumption and low maintenance cost; When feeding at the end, it can adapt to the requirements of uneven feeding, and can complete various process requirements such as conveying, stirring and mixing at the same time, and there will be no jamming phenomenon when the material enters too much; It is convenient for multi-point loading and unloading, and can transport materials with higher temperatures. Suitable for horizontal transportation of high-temperature materials; It has good adaptability to high temperature, uneven feeding, materials with anti-crushing requirements, anti-pollution requirements and processes that require multi-point unloading. Practice has proved that it has a good effect when conveying materials such as cement clinker, dry limestone, phosphate ore, ilmenite powder, coal and slag.
The particle size of the material added by the end feed port cannot be greater than 1/4 of the spiral diameter; The particle size of the material fed from the middle feed port shall not be greater than 30 mm. In order to ensure that the cylinder does not deform, the feeding temperature must be controlled below 300 °C. The machine has extremely serious wear on the blades and troughs when transporting abrasive materials. The screw conveyor designed this time is mainly used to transport silicon powder, and its grinding ability is very large, so it is not suitable for screw pipe conveyor.
Bendable screw conveyor
The spirochete mandrel is flexible, so the conveyor line can be arranged according to the spatial curve according to the needs. According to the length ratio of the horizontal and vertical (large inclination) sections in the layout line, its working principle is designed according to ordinary screw conveyor or vertical screw conveyor.
It is used for occasions where the conveying line needs to be arbitrarily arranged according to the spatial curve to avoid material reloading; When too much material enters the casing or there are hard materials, the spiral body will float freely and will not cause jamming; Low noise. It is mainly used to complete the horizontal and vertical conveying of materials at the same time. When conveying vertically, the speed is generally required to be high, not less than 1000r/min.
