Screw Feeder & Conveyor Models: Options and Accessories
Screw feeders and conveyors are available in a wide range of models, types, and configurations to meet the specific needs of different industries, material characteristics, and process requirements. Depending on factors such as material characteristics, flow rate requirements, hygiene standards, and layout constraints, different screw conveyor models can be selected. Polimak offers a diverse portfolio of screw conveyor and feeder solutions tailored to a wide range of industries and applications.
Our common models and configurations include:
Based on the shape of the conveyor:
• Tubular Screw Conveyors
• U Type Screw Feeders
Based on the material of construction:
• Stainless Steel Screw Conveyors
• Hardox Screw Conveyors
Based on the number of inlets or outlets:
• Screw Conveyors with Multiple Inlet Ports
• Screw Conveyors with Multiple Outlet Ports
Other specialized configurations:
• Mobile Screw Conveyor with Hopper
• Dosing Screw Feeder
• Microdosing Screw Feeder
• Custom-Designed Screw Feeders and Conveyors
Screw Conveyor Types, Models, and Configurations
There are several types of screw feeders and conveyors. Depending on process requirements, screw conveyor configurations may vary.
Tubular Screw Conveyors
Tubular screw conveyors are widely used for moving bulk materials in a controlled and enclosed manner. These systems feature a cylindrical housing that fully encloses the internal components, ensuring minimal spillage and protection from external contaminants.
Inside the tube, a rotating helical blade, also known as an auger, is installed on a central shaft. As the screw turns, it pushes material along the length of the tube from the loading point to the discharge outlet.
Tubular screw conveyors are commonly used in the food, chemical, and polymer industries, as well as in various other industrial applications.
U Type Screw Feeders
U-type screw feeders are designed with a trough-like structure, shaped like a “U” or sometimes a shallow “V”. This structure helps maintain a steady flow of material while minimizing blockages during operation.
The open design allows for easy monitoring of how materials move through the feeder during operation. This is particularly useful when handling sticky or viscous products such as clay, adhesive resins, pastes, or polymer blends, which are prone to buildup or clogging.
Removable lids installed above the screw mechanism make routine maintenance easier and help maintain sanitary operating conditions. The removable cover makes it convenient to clean the interior and perform inspections or part replacements without dismantling the entire system, reducing downtime and maintenance effort.
Stainless Steel Screw Conveyors
Stainless steel screw conveyors are widely used in industries requiring high hygiene standards. They are used to transport dry ingredients like flour and sugar in food production, move powdered products during processing, and handle granulated supplements in packaging. Also, in pharmaceuticals, they safely transport active ingredients while ensuring strict cleanliness.
Hardox Screw Conveyors
Hardox screw conveyors are specifically designed to handle abrasive materials that would quickly wear down standard equipment. The helicoid screws in these conveyors are manufactured from Hardox steel, a highly durable and wear-resistant material.
This special construction extends the lifespan of the screws, allowing them to withstand harsh conditions and abrasive substances such as minerals, ores, and heavy-duty industrial powders. As a result, Hardox screw conveyors provide a reliable and cost-effective solution for industries dealing with tough, abrasive products.
Screw Conveyors with Multiple Inlet Ports
Screw conveyors equipped with multiple inlet ports are designed to collect bulk solids from various locations within a process or production line. These inlets allow different products or batches to be fed simultaneously or sequentially into the conveyor system. The conveyor then transports the combined material efficiently to a single receiving point for further processing, packaging, or storage. This configuration improves operational flexibility, reduces the need for multiple screw conveyors, and optimizes material handling in complex industrial environments.
Screw Conveyors with Multiple Outlet Ports for Controlled Distribution
Screw conveyors with multiple outlet ports are designed to distribute material to several processes either simultaneously or sequentially. Additionally, slide gate valves or butterfly valves are installed at each outlet to regulate the flow of material. These valves allow precise control over how much material is released, ensuring each downstream process receives the correct amount. This configuration enhances efficiency and flexibility in complex production lines requiring controlled material distribution.
Mobile Screw Conveyor with Hopper
Mobile screw conveyors with hoppers offer great flexibility by allowing easy relocation within different areas of a production facility. Equipped with wheels, these conveyors can be moved and positioned wherever bulk material transfer is needed, reducing downtime and improving workflow efficiency.
In addition, mobile conveyors can be equipped with weighing equipment, making them ideal for applications where precise measurement of bulk materials is necessary. This integration allows operators to monitor and control the amount of material being conveyed in real-time, ensuring accuracy and consistency in production processes.
Dosing Screw Feeder
A dosing screw feeder is a specialized equipment designed to control the quantity of bulk material delivered into a production process. It is widely used across various industries such as food processing, chemicals, and plastics, where accurate dosing is essential for maintaining product quality and consistency.
There are two main types of dosing: volumetric and gravimetric. In volumetric dosing, the amount of material fed is regulated by adjusting the rotational speed of the screw feeder’s shaft. This mechanism controls the volume of product moved over time. On the other hand, gravimetric dosing systems are used for applications requiring even greater accuracy. They combine the screw feeder with weighing scales, allowing the material flow to be continuously measured and adjusted based on weight, ensuring precise and consistent feed rates during the handling process.
Microdosing Screw Feeder
Microdosing screw feeders are engineered to deliver very small and highly accurate quantities of material, making them ideal for processes that require exact dosing on a minute scale.
These special feeders are used in industries such as pharmaceuticals, food additives, and specialty chemicals, where precision is critical. Their design ensures consistent and controlled flow of fine powders, granules, or other materials, preventing overfeeding or underfeeding. This level of accuracy helps improve product quality, reduce waste, and optimize overall process efficiency.
Custom-Designed Screw Feeders and Conveyors
In addition to a wide selection of standard screw feeders and conveyors, Polimak offers custom-designed solutions tailored to specific process needs.We are committed to creating equipment that meet unique requirements, ensuring efficient and reliable material handling. Our expert engineering ensures solutions that enhance performance and effectively overcome complex industrial challenges.
These valves are typically actuated by pneumatic actuators and are used to automatically open and close the product flow to discharge material to downstream equipment.
Installed below silos or hoppers, these valves are used for maintenance operations of equipment such as rotary valves, screw feeders, etc., that are positioned below the butterfly valve.
These valves are typically actuated by pneumatic actuators and are used to automatically open and close the product flow to discharge material to downstream equipment.
In this design, the butterfly valve is sandwiched between two flanges. Rubber sealing at both faces of the valve provides a tight seal between the flanges and the wafer butterfly valve.
One side of the valve has a bolted flange connection, while the other side features a built-in short pipe designed for fixing a flexible sleeve.
These valves have bolted flange connections on both sides, making them suitable for installation on silos, hoppers, screw feeders, and similar applications.
Bulk tanker trucks or open trucks can be filled with powdered materials delivered within FIBC bags. These systems generally consist of bulk bag discharging station, mechanical or pneumatic conveyor and loading bellow. Big bag discharge station transfers the bulk solid from big bag to conveying system. Conveying system transfers it to truck loading area. And loading bellow is used to fill tanker truck without any dust emission. Since truck loading operations are done within limited time, high capacity big bag discharge systems and bulk material conveying systems are used. For short distances, screw conveyors are preferred to transfer material from big bag discharge station to truck loading chute. For long conveying distances, pneumatic conveying systems provide better service. There may exist a storage hopper or silo above bulk truck loading bellow to compensate material flow between inlet and outlet. Bulk bag discharge and truck filling systems have automatic control system that monitors product level in truck and operates all equipment accordingly. Optional weighing system can be added to measure the amount of material that is filled to truck.
Big bag discharge systems can deliver dry bulk solids in powder and granular form to weighing and batching systems. The loading hopper of the weighing system should remain full during dosing and batching. Big bag discharge systems can monitor the product level in the loading hopper and maintain a constant level automatically. Depending on the dosing speed and conveying distance, mechanical conveying systems or pneumatic loading systems may be used. Dust collectors can be employed to prevent dust emissions during hopper loading, especially for materials with high dust content.
Dry bulk packaging systems are used to fill powdered or granular materials into bags, drums, jars, sacks, etc. Bulk materials delivered in big bags must be transferred to packaging machines without interruption. The loading hopper of the packaging system should remain full during the filling and packaging process. Big bag discharge systems can monitor the product level in the loading hopper and maintain a constant level automatically. Depending on the packaging speed, mechanical conveying systems or pneumatic loading systems can be selected. Dust collectors can be used to prevent dust emissions during hopper loading, especially for materials with high dust content.
Mixer automation systems are used to mix dry bulk solids according to specific recipes. Raw materials delivered in FIBC bags can be transferred to mixing units through a combination of conveying equipment and bulk bag discharge systems. Depending on the type of application, pneumatic conveying or mechanical feeding systems can be used to fill mixers. Big bag discharge stations can be manufactured with built-in dosing systems. The amount of raw material to be loaded into the mixer is automatically controlled with the help of a weighing and dosing system. Dust collectors can be used to prevent dust emissions during the mixer filling process.
Bulk material stored in big bags can be automatically filled into small bags. Big bag discharge systems come with optional built-in bag filling units. For low filling capacities, these units are installed below the big bag discharge hopper, providing a practical and cost-effective solution. Both big bag discharging and bag filling operations can be handled by a single, compact system. For higher bag filling needs, bag filling machines are installed near the bulk bag discharge stations. Pneumatic conveying systems or mechanical conveyors can be used to transfer bulk material from the FIBC bag discharge station to the bag or sack filling system.
Mechanical conveyors can be used for silo loading from big bag discharge stations. Screw feeders, bucket elevators, rotary valves, or chain conveyors are connected to big bag discharge stations to fill silos. The selection of conveying equipment directly depends on the conveying distance, height, transferred material, and capacity. Bucket elevators are preferred for high silos, while screw feeders are preferred for shorter silos and short distances. The big bag discharge system can be installed on top of the silo for faster filling. In this case, rotary valves or butterfly valves are better choices as they provide simple flow control. Dust collection systems may be required depending on the dust content of the bulk solid. During silo loading, air content in the silo escapes to the atmosphere and carries some dust along with it. Vacuum fans and jet filters in dust collectors prevent dust emissions into the environment. The collected dust is sent back to the silo, thus preventing product loss.
Pneumatic conveying systems installed after bulk bag discharge units transfer bulk material through conveying pipelines to fill silos. This configuration is useful in applications where high transfer rates and long conveying distances are needed. In production lines where raw materials are stored in warehouses far from storage silos, bulk bag discharge stations can be installed close to the warehouses, and pneumatic conveying systems are used to fill silos from long distances. This design reduces the need for forklifts and cranes for bulk material transfer on the production site and increases overall efficiency.
Pneumatic conveying systems used for silo loading utilize blower pumps or compressors. Motor power, pipeline diameter, and equipment selection depend on the type of bulk material, transfer distance, silo height, and transfer capacity. Level sensors, jet filters, and other equipment are installed on storage silos to ensure the proper operation of the silo filling system.
Pneumatic conveying systems installed after bag dump units transfer bulk material through pipelines to fill silos. This configuration is ideal for applications requiring high transfer rates and long conveying distances. In production lines where raw materials are stored in warehouses far from storage silos, bag dump stations can be installed close to warehouses, allowing pneumatic conveying systems to transport materials over long distances. This design reduces the excessive use of forklifts and cranes for bulk material transfer within the production site, improving overall efficiency.
Pneumatic transfer systems used for silo loading utilize blower pumps or compressors. Motor power, pipeline diameter, and equipment selection depend on factors such as the type of bulk material, transfer distance, silo height, and transfer capacity. Level sensors, jet filters, and other equipment are installed on storage silos to ensure the proper operation of the silo filling system.
Mechanical conveyors can be used for silo loading from bag dump stations. In this configuration, screw feeders, bucket elevators, rotary valves, or chain conveyors are connected to bag dump stations to fill silos. The selection of conveying equipment depends on factors such as conveying distance, height, material properties, and capacity. Bucket elevators are preferred for high silos, while screw feeders are ideal for shorter silos and short distances. Bag dump systems can be installed on top of the silo for faster filling. In such cases, rotary valves or butterfly valves are better choices as they provide simple flow control.
Dust collection systems may be required depending on the dust content of the bulk solid. During silo loading, air inside the silo escapes to the atmosphere, carrying dust particles with it. Dust collectors equipped with a vacuum fan and jet filter capture airborne dust. The collected dust is returned to the silo, preventing product loss and ensuring a cleaner environment.
The inlet skirt is an optional feature designed to extend the lifespan of the flexible connector sleeve. Its upper portion is attached to the outlet port of the upstream equipment and extends down into the bin activator’s inlet port. The primary function of the inlet skirt is to serve as a protective shield, safeguarding the flexible connector seal from wear and damage.
A vibratory motor is externally mounted to the bin activator. When powered, the motor generates vibrations that facilitate a steady flow of dry bulk materials within the system. Depending on the application requirements, one or two vibratory motors can be installed externally.
To accommodate a bin activator, the cone of a silo must be shorter than usual, resulting in a wider outlet. A flange supplied with the bin activator is separately welded to the silo’s outlet, slightly above the opening, at the production site. Once installed, the vibrating bin discharger is securely bolted to the flange, ensuring a stable and reliable connection.
Special spring suspension links and an engineered polymer seal work together to create a flexible connection between a vibrating bin discharger and the equipment positioned above it.
The proper design and installation of the polyurethane seal prevent it from slipping off and ensure a secure seal, eliminating the risk of dry bulk material leakage. Additionally, the seal offers high stress resistance and long-term durability, withstanding stresses caused by motor vibrations, pressure conditions, and other operational factors.
Externally installed spring suspensions provide full resilience to the vibrations of the cone head. They ensure that the generated vibrations affect only the cone itself rather than the upstream equipment structure.
An internally tapered, conical-shaped baffle plate is positioned at the center of the bin activator’s diameter. The baffle is rigidly attached to the equipment body using structural steel components. It facilitates bulk material flow from upstream equipment by directly inducing vibrations into the material.
A secondary deflector plate reduces the weight of the bulk material in the lower portion of the bin activator by acting as a wedge beneath the material, directing it around the areas adjacent to the cone’s surface.
Polimak baffle plates are available in various configurations, including convex and cone plates, and in different angles (15°, 30°, 45°, or even 60°) depending on the flow characteristics of the handled bulk material and the specific application requirements.
