Vertical Screw Conveyors

How do Vertical Screw Conveyors Work?

Vertical Screw Conveyors are used to convey materials vertically or at a steep angle from low to high locations. Their operating principle is unique and ingenious. The core of a Vertical Screw Conveyor's operation is to utilize high-speed rotating spiral blades to exert centrifugal force and thrust on the material within a closed vertical housing, achieving continuous lifting. When material enters the feed port at the bottom of the device, it falls onto the rotating spiral blades. As the spiral blades rotate at a high linear speed, they generate a strong centrifugal force, throwing the material toward the inner wall of the casing. Simultaneously, the inclination angle and rotation direction of the spiral blades generate an upward axial thrust. This thrust, combined with the friction between the material and the inner wall of the casing, prevents the material from sliding downward due to gravity. The high-speed rotation of the blades continuously pushes the incoming material into the gaps between the previous blades, forming a continuous, upward spiraling flow of material within the casing. Unlike horizontal screw conveyors, which rely on blades to propel the material along the bottom of the trough, vertical screw conveyors rely primarily on centrifugal force to maintain the material against the outer wall of the casing, combined with the thrust of the spiral blades to achieve vertical lift. This operating method ensures that the material does not accumulate at the bottom due to gravity during the lifting process and reduces relative slip between the material and the blades, thereby improving conveying efficiency. This unique operating mode makes vertical screw conveyors particularly suitable for handling free-flowing bulk materials such as grain, flour, cement, and sand. They can stably lift materials to a predetermined height, making them indispensable vertical material conveying equipment in many industrial production lines.

What is the structure of Vertical Screw Conveyors?

The structure of Vertical Screw Conveyors mainly consists of the following core parts. The screw is its key component, which includes a screw shaft as the core, which is usually solid or hollow, responsible for supporting the blades and transmitting power; and a spiral blade fixed on the shaft. The screw is usually wrapped in a cylinder, most of which are circular and closed, to ensure that the material does not fall when it is lifted vertically, and to maintain the internal pressure and conveying efficiency. The feed port is located at the bottom of the conveyor and is the port for the material to enter. It can be fed in by gravity or forced feeding. After reaching the preset height, the material is discharged from the discharge port at the top to connect to the silo, weighing bucket or other equipment. The drive device that provides the power for the screw to rotate is usually composed of an electric motor, a reducer and a coupling. It is generally placed at the top or bottom of the conveyor. Its power selection is related to the conveying capacity, lifting height and material characteristics. Bearings are used to support the screw shaft and reduce friction, including the bottom, top, and intermediate suspension bearings that may be set when the lifting height is large. They bear different loads and ensure operational stability. Finally, the support structure is the frame or bracket that supports the entire conveyor equipment to ensure its stable operation.

What are the product specifications of Vertical Screw Conveyors?

The technical parameters of Vertical Screw Conveyors are usually determined and adjusted according to the nature of the conveyed material, conveying capacity, lifting height and on-site working conditions. The conveying capacity is usually expressed in cubic meters per hour (m³/h) or tons per hour (t/h). Its size is affected by factors such as screw diameter, speed, screw pitch, material properties (such as bulk density, repose angle) and filling factor. For example, the conveying capacity of ordinary cement can range from 3 m³/h to 95 m³/h. The lifting height generally ranges from a few meters to tens of meters. When the height is large, special design may be required to avoid bending and deformation of the screw shaft. The screw diameter, that is, the outer diameter of the screw blade, directly affects the conveying capacity, usually ranging from 100mm to 600mm or more. The screw speed (r/min) must ensure that the material can move upward. If it is too low, it may not be lifted, and if it is too high, it will increase wear. The drive power (kW) is provided by the drive motor and is related to the conveying capacity, lifting height, material properties and equipment efficiency. Material properties include bulk density, particle size, humidity, abrasiveness, viscosity, temperature, etc., which directly affect the selection, design and material selection of the conveyor. For example, highly abrasive materials require wear-resistant materials to make the spiral blades and barrel. Common materials for the trough or cylinder are carbon steel and stainless steel. The feeding methods are divided into self-flowing (suitable for materials with good fluidity) and forced feeding (suitable for materials with poor fluidity or stable feeding).

What are the uses of Vertical Screw Conveyors?

The main function of Vertical Screw Conveyors is to achieve vertical lifting of materials. They usually work in conjunction with other conveying equipment to jointly build a complete material conveying system. Its core function is to lift materials from a lower receiving point to a higher position, such as from a ground silo or hopper to a high storage tank, weighing hopper or subsequent processing equipment. The lifting height can reach 1 meter to 15 meters or even higher. Some equipment also has a forced feeding function. Through a horizontal screw feeder or a special feeding device, it ensures that the material enters the vertical lifting section evenly and stably to prevent blockage; at the same time, its discharge port design supports multi-point unloading at high altitudes, or directly conveys to the next processing link. Compared with other vertical conveying equipment, Vertical Screw Conveyors usually occupy less space and are suitable for working conditions with limited space. In addition, its closed cylinder structure helps reduce dust and material loss, which is beneficial to environmental protection. It is especially suitable for scenes with high cleanliness requirements or for conveying toxic, flammable, and explosive materials. In some applications, through special spiral blade design or additional devices in the barrel, Vertical Screw Conveyors can also achieve auxiliary process operations such as mixing, stirring, cooling or heating of materials during the conveying process, such as ensuring constant feeding speed and further mixing of sludge in sludge treatment.

Vertical Screw Conveyors Manufacturers

Vertical screw conveyors face diverse requirements across various industries and operating conditions. One of their manufacturers' core capabilities is customization. This capability enables the equipment to precisely match specific material properties, conveying capacity, lifting height, and on-site installation conditions.

Vertical screw conveyors customization primarily involves adjusting core parameters. For example, manufacturers adjust the material, thickness, and pitch of the screw blades based on the bulk density, abrasiveness, or viscosity of the material. For applications handling corrosive materials, stainless steel screw bodies and casings are typically chosen. For conveying highly abrasive materials, wear-resistant steel or hardened blade edges are used. Secondary flexibility is the equipment's size and structure. The diameter, lifting height, and inlet and outlet locations of Vertical Screw Conveyors are not fixed, but can be precisely designed based on the customer's actual production line layout. Based on the on-site drawings provided by the customer, the manufacturer will adjust the overall height of the equipment and design a suitable inlet hopper and outlet to ensure it can seamlessly integrate into the existing production system. For example, in areas with limited space, a customized compact design can maximize space utilization; in situations where frequent movement is required, Vertical Screw Conveyors with a mobile base can meet their flexibility needs.

The selection of Vertical Screw Conveyors requires comprehensive consideration of the specific characteristics of the material, including its bulk density, particle size, abrasiveness and viscosity, which directly affect the selection and material requirements of the equipment. At the same time, clarifying the required conveying volume and lifting height is the basis for determining the screw diameter, speed and drive power. For applications that require the handling of special materials or face complex working conditions, customized equipment can be selected, and the manufacturer can adjust the spiral blades, barrel material or feeding method. In addition, our manufacturer's services are perfect, including the ability to install, debug and provide subsequent maintenance support. Choosing the right Vertical Screw Conveyors is a practical consideration to ensure the stable operation of the material conveying process.