A screw conveyor, also known as an auger conveyor, is a highly efficient mechanical device designed to transport various materials, including semi-solid materials and granular substances. It operates by utilizing a rotating helical screw blade, referred to as ‘flighting,’ enclosed within a cylindrical tube. Screw conveyors find extensive applications across numerous industries involved in bulk material handling. They provide a reliable and versatile solution for smoothly moving substances such as grains, powders, chemicals, and more. With their ability to accommodate different angles, lengths, and capacities, screw conveyors offer customizable configurations to meet specific requirements. Whether it’s facilitating the material transfer, aiding in mixing processes, or assisting in bulk storage, screw conveyors play a pivotal role in streamlining industrial operations.
Screw conveyors are a necessity in a number of industries that need to work on a bulk transfer of various materials. They complement manual labor and improve both safety and efficiency in the industry. Based on the fact that there are different bulk materials and other variations in bulk handling, it follows that there’s a lot of important information to learn about them. This knowledge can make it easier to differentiate between the various details that go into finding the right screw conveyor, setting it up, and other details.
Applications of Screw Conveyor
Screw conveyors have several uses in the industrial setting and outlined below are a few of them.
Bulk Material Handling
Screw conveyors play a vital role in industries that require efficient handling of bulk materials, facilitating the transportation of such materials from one point to another. These industries encompass various sectors including construction, mining, agriculture, and more.
Screw conveyors play a crucial role in the agricultural sector, particularly in the transportation of grains from one location to another. This process is essential after harvesting and during various stages of agricultural operations. Typically, a standard configuration includes a hopper that receives the grains from their source, such as a truck or cart. At the upper end, a chute guides the grains to their intended destination, which could be a silo or a packaging area. An electric motor provides the necessary power to operate the entire setup.
Screw conveyors facilitate the movement of various forms of bulk food materials from one point to another. These materials can include food powders, raw ingredients, and ready-to-eat foods. To ensure cleanliness and safe handling, it is essential to employ a screw conveyor setup that meets the appropriate specifications. In this industry, the use of a reliable screw conveyor enables accurate dosing and precise measurement, promoting efficient and precise handling of food materials.
In mining, screw conveyors are used to move either the final material being mined from its origin to a processing point, or from the processing point to a packaging or other final destination. This saves time and ensures that manual labor is used to a minimum degree, securing the safety of miners.
In the pharmaceutical setting, screw conveyors are used in processes like packaging, filling, and capping. It ensures that capsules, tablets, granules, and other pharmaceutical materials are handled safely and efficiently. This means that they end up germ-free, safe from damage, and they’re measured accurately.
Industrial processes are typically those for which there are additional steps that need to be taken after bulk material is moved from one point to another. Various processes screw conveyors can help make them more efficient, and a few are outlined below.
Mixing and Blending
One of these industrial processes is mixing and blending various materials. A screw conveyor can make it easier to accurately and thoroughly mix and blend different powders or granules, for example, before they’re packed or sent to a final process.
Drying and Cooling
Some bulk material calls for cooling or drying before the next process can take place. For this, a proper screw conveyor can help dry or cool bulk materials while at the same time getting them closer to the final point at which they’re required.
Feeding and Discharging
Feeding and discharging are other industrial processes that the right screw conveyor can help with. That’s because the screw conveyor can be set to discharge a specific amount of bulk material at given intervals. This material will either be fed into the next process or discharged to give way to more bulk material.
Screw conveyors are used in packaging and they help by ensuring that a metered amount is fed into the relevant container or bag. Bulk materials such as cement, salt, and various chemicals can be safely measured into their packaging bags and containers, making the entire process more efficient.
Types of Screw Conveyors
Screw conveyors are versatile tools with numerous applications due to the wide range of materials, industrial environments, and safety concerns involved in handling bulk materials. Consequently, different types of screw conveyors have been developed to cater to these diverse needs. Selecting the right type is crucial for achieving optimal results. Here are some common types of conveyors used across various industries and at different stages of bulk material handling.
Horizontal Screw Conveyor
Horizontal screw conveyors are one of the most popular types. This is thanks to its simple nature, coupled with a design that’s easy to use. A horizontal screw conveyor consists of a trough with a drive unit at the discharge end. This design allows for the material to be pulled towards the discharge, resulting in reduced conveyor wear. The straightforward nature of horizontal screw conveyors makes them highly favored in various industries.
The construction of a helicoid conveyor differs from that of other types. It consists of a flat bar or strip of steel that’s been cold-rolled to form a helix. Additionally, a smooth and reinforced flighting material is formed using the same metal strip. As a result, the helicoid conveyor is well-suited for handling materials that range from light to moderately abrasive, such as fertilizer and limestone. This design ensures efficient and reliable material transportation.
A sectional conveyor consists of flights that have been constructed from flat steel discs that have uniform diameters on the inside and the outside. These are cut by laser, water jet, or plasma to extend the length of the conveyor and then pressed to form a helix that has an individual flight corresponding to one revolution. These screw conveyors are ideal for conveying highly abrasive materials, like alumina and glass cullet.
The u-trough conveyor is typically a screw conveyor that’s paired with a u-shaped trough. This makes for a simple construction that’s cost-effective to set up and use.
A tubular conveyor, also known as a tubular drag conveyor, is designed to smoothly transport bulk materials through stainless steel tubing. It utilizes low-friction polymer discs that are connected to a stainless steel cable. The setup is driven by a wheel placed at one end of the circuit, with another wheel placed at the other end for tension.
Inclined Screw Conveyor
Inclined screw conveyors convey and elevate bulk material from one level to another. The correct design is based on the objective as well as the specific bulk material that’s getting conveyed.
A shaftless screw conveyor has a single helix or spiral, but no central shaft. It rotates on a liner that’s usually made out of engineering plastic, connected at the end to a drive. While it can be long and run faster, it’s not well-suited to pasty or fibrous materials.
Vertical Screw Conveyor
This screw conveyor typically elevates bulk material at a steep incline, therefore taking up little space. It has few moving parts and can be constructed from a number of different materials to make it better suited to various consistency of bulk materials.
Flexible Screw Conveyor
A flexible screw conveyor, also known as an auger screw conveyor, is a highly efficient and versatile conveyor system. It is capable of conveying a wide range of bulk materials, including sub-micron powders and large pellets. Whether the materials are free-flowing or non-free flowing, and even when blended, this type of conveyor ensures minimal separation. Due to its high level of customization, the flexible screw conveyor proves to be an excellent choice for various industries.
A screw-lift conveyor is typically used by those who want a solution that takes up minimal floor space. There are various configurations to choose from, meaning that they can be used for a number of materials as long as they’re not extremely abrasive.
Screw Conveyor Components
Screw conveyors are typically made from a number of components. These are put together according to the specifics of a client’s needs, with each one playing a specific role. Have a look at the main components of a screw conveyor to learn more about the inner workings of these equipments.
This component of a screw conveyor is a shaft that’s inserted and bolted into the center pipe of the screw. The shaft has a variable diameter depending on the specific design. Most screw shafts are made out of a carbon steel bar of a given grade. This is because this material is easy to machine, economical, strong, and relatively hard.
Screw flights are scrapers that are mounted at varying intervals on a conveyor trough perpendicular to the direction in which bulk material travels. These are responsible for holding the bulk material and pushing it along the trough on which they sit as it gets moved along the system.
When a screw conveyor has multiple screw sections, these sections are supported by hanger bearings. These components are available either in plain type or as journal bearings. When they wear out, they can be replaced by new ones.
Troughs and Casings
The casing or trough is the housing that contains the screw itself. Powder bulk material rides on the trough or casing, and it can be made out of various materials, in different shapes, and mostly comes in standard lengths. It’s important to choose the right specifications depending on things like the abrasiveness of the material in question and the space available.
This final component is mounted on the end of a screw conveyor and consists of a shaft-mounted speed reducer, an adapter with shaft seals, a removable steel shaft, and a steel motor mounting bracket. This part powers the entire conveyor and maybe a simple motor or an assembly of parts.
Advantages of Screw Conveyors
Screw conveyors offer several advantages that make them a popular choice over other types of conveyors. These reasons explain why people often prefer them:
- Versatility: They’re versatile enough to be used with different types of materials and in a number of different-sized spaces.
- Efficiency: They’re also very efficient because the setup is fast and easy. Most moving parts are easy to replace when they wear out, ensuring continued service for a long time.
- Space-Saving Design: As they’re available in different designs, it’s possible to get a screw conveyor no matter how small or hectic the space available for one is.
- Customizability: It’s possible to customize screw conveyors and make them meet a specific set of requirements. This makes them some of the best options to pick for a number of bulk material processes.
Limitations of Screw Conveyors
These conveyors also have some limitations to their use and outlined are a few of them.
- Material Limitations: There are limitations to the type and nature of material that can be conveyed with screw conveyors.
- Potential Jamming or Clogging: When the bulk material is sticky or particularly fine, a number of screw conveyors will typically clog and jam up.
- Higher Initial Investment: While screw conveyors are easy to maintain, they typically have a higher initial investment cost to buy and set up.
- Maintenance Requirements: It’s important to know that without regular and proper maintenance, many things can go wrong with a screw conveyor.
Screw Conveyor Maintenance
Regular inspection and cleaning of a screw conveyor is necessary to address clogs and other issues:
- Inspection and Cleaning: A screw conveyor will have to be inspected and cleaned regularly by a professional to deal with clogs and more.
- Component Replacement: Some components in a screw conveyor may be longer-lasting than others, but most will need to be replaced at one point or another.
- Troubleshooting: Whenever something goes wrong, it will generally take a professional to troubleshoot the issue in question.
- Safety Guidelines: Failure to follow the safety guidelines of a screw conveyor can lead to unprecedented problems.
Screw Conveyor Safety
Ensuring the safe operation of screw conveyors is of utmost importance to prevent accidents and maintain productivity. Proper safety measures should be implemented to protect workers and prevent equipment damage. The following aspects are crucial for screw conveyor safety:
- Guarding and Enclosures: These are put in place to ensure that there’s minimal risk of something ending up in the system of the conveyor that should not be there.
- Emergency Stop Systems: Given the risk of something getting caught in some types of screw conveyors, it’s crucial to have functional emergency stop systems in place.
- Training and Awareness: Anyone who will operate a screw conveyor must be trained on the right way to operate it so that they don’t cause an issue.
- Hazard Identification and Risk Assessment: It should be possible for those operating and manning screw conveyors to identify hazards before they get out of hand.
Innovations in Screw Conveyor Technology
Innovations in screw conveyor technology have brought significant advancements to improve the efficiency, safety, and customization of these systems. The following are some key developments in the field:
- Automated Control Systems: It’s currently possible to automate the control system of a screw conveyor system and make the process more efficient.
- Material-specific Design Enhancements: Thanks to advancements in materials and other details of screw conveyors, you can get the perfect conveyor for your specific needs.
- Energy-efficient Drive Systems: To enhance the energy efficiency of conveyor systems, there are multiple implementations available.
- Integration with IoT and Industry 4.0: As industries change and grow, it’s becoming possible to integrate screw conveyors with IoT and Industry 4.0.
Screw conveyors can be the perfect addition to several industries. To get the best outcome from them, it’s important to get advice from a team of professionals knowledgeable in this field. Sodimate offers extensive solutions in this regard, ensuring that you can get a functional and efficient setup for your needs, give us a call.