Screw Conveyor Manufacturers and Companies

Screw Conveyors

Screw conveyor systems are mechanisms designed to rotate or transport various materials, including fluids, solids, and granulated substances, from one stage of a process to another. In other words, they facilitate the seamless transfer of materials.

These conveyors are also referred to as auger conveyors, helix conveyors, worm conveyors, or flexible screw conveyors.

The History of Screw Conveyors

In the third century B.C., the ancient mathematician and scientist Archimedes theorized the screw principle and designed the first screw conveyor system, known as Archimedes' screw. This early screw conveyor consisted of a hollow cylinder with a central shaft and a spiral fixed to the inner cylinder wall and the shaft. His contemporaries used this design primarily for irrigating farmland and removing water from ships.

The modern screw conveyor system evolved between the late 1800s and the mid-1900s. Initially, it was introduced in the United States to enhance feed and grain production on farms. It became a critical component of the first feed mills, a role it continues to serve today.

As advancements in construction materials, such as abrasion-resistant alloys and stainless steel, have emerged over the years, screw conveyors have expanded into a wide range of industries. Improvements in production technology, including automation, have further enhanced their quality and cost-effectiveness. One notable example is robotic welding in the screw-making process. A more recent innovation is the shaftless screw conveyor, which eliminates the need for a center pipe. Companies looking to integrate this cutting-edge equipment into their operations can find expert suppliers on IQS Directory .

As bulk material handling technology continues to advance, we can anticipate even more innovations in the field.

Benefits of Screw Conveyors

Low Cost
Portable screw conveyors are among the most affordable conveyor options available, which is a major reason for their widespread adoption. Compared to other conveyor systems, they are the least expensive choice. The overall cost depends on factors such as tube type, conveyor length, motor size, capacity, and additional custom features. Thanks to their compact size and intelligent design, portable screw conveyors are well-suited for a wide range of applications, even for those with budget constraints.

Material Support
These highly efficient machines are designed to handle and transport thousands of different materials. They can move everything from powders and mixtures to pallets and granules with ease. IQS Directory provides access to companies that specialize in designing optimized screw conveyors for various industrial applications.

No Degradation
Modern flexible screw conveyors significantly minimize material degradation. However, to ensure the best results, it is crucial to use them with the appropriate materials for the given process. Selecting a machine specifically suited to your application is essential for maintaining product integrity and achieving optimal performance.

Device Speed
The flow rate or speed of a portable screw conveyor depends on its capacity, as well as the type and amount of material being transported. These conveyors can be designed to achieve the precise speed necessary to support specific processing requirements.

How Conveyors Work

Screw conveyors operate based on the Archimedes’ screw principle, which states that a rotating screw or auger, when properly fitted into a tube or cylinder, can move material in a chosen direction. With each rotation, new material continuously enters the tube, ensuring a steady flow.

Using this principle, screw conveyors transport bulk material from one point to another by means of a rotating helical screw enclosed within a trough or tubular casing. Some screw conveyors are powered by an electric motor, while others operate without a conveyor drive, utilizing energy from nearby machinery, such as a trailer’s power take-off shaft. The material moves at a precise flow rate, typically measured in cubic feet per hour, though in industrial bulk processing, capacity may also be measured in pounds per hour or tons per hour.

Screw Conveyors Images, Diagrams and Visual Concepts

Types of Screw Conveyors

Screw conveyors are available in a variety of types, classified based on their mechanism and placement within a tube or cylinder.

Tubular Screw Conveyor
A general term for any screw conveyor enclosed within a tube. Many screw conveyors, regardless of their conveying style, can also be classified as tubular screw conveyors.

Vertical Screw Conveyors
Designed for bulky material handling in manufacturing and agriculture, these conveyors optimize space by moving materials vertically, reducing the required floor area. Despite their compact design, they handle heavy loads efficiently.

Horizontal Screw Conveyor
Similar to vertical conveyors but designed for horizontal movement, these are commonly used in chemical plants for fluid and gas management, as well as for heating, cooling, mixing, dewatering, drying, aeration, and compaction processes.

Stainless Steel Screw Conveyors
Utilizing an inclined, spiraling plane, these conveyors transport liquids, granules, and semi-solid materials. They are widely used in industries such as food processing, pulp and paper, wastewater treatment, chemicals, wineries, and brewing.

Screw Feeder Conveyor
A specialized version of the horizontal screw conveyor designed to operate at full capacity, unlike standard horizontal conveyors, which typically run at 40-50% efficiency. These are used for the continuous and consistent movement of materials between processes.

Portable Screw Conveyors
Designed for moving granulated and powdered materials, these conveyors can be set at custom angles between 45 and 90 degrees, making them highly adaptable for different applications.

Inclined (Incline) Conveyor
Used when materials need to be transported at an angle, these conveyors require more space and power but provide an economical way to move bulk materials between facility floors. Some models are portable and mounted on stands, carts, or vehicles for mobility.

Bucket Elevator
A vertical or inclined conveyor that moves materials using one or more buckets. Used for conveying flowable bulk material up and down, bucket elevators function similarly to screw conveyors but have a different design.

Coreless Screw Conveyor
Also known as shaftless screw conveyors, these conveyors lack a central shaft, making them highly resistant to clogging and effective for capturing and transporting stringy materials.

Sand Screw Conveyor
Primarily used for dewatering sand or granules, this type also helps remove fine particles from materials.

Grain Screw Conveyor
Common in agriculture, this conveyor, also known as an agricultural screw elevator, is used for lifting and loading grain into trucks.

Plastic Screw Conveyor
A lightweight bulk material transport system that moves raw materials using a rotating helical screw inside a trough or tubular casing.

Cement Screw Conveyor
A specialized screw conveyor designed explicitly for transporting cement efficiently and reliably.

Applications of Screw Conveyors

Industries use screw conveyors primarily to reduce maintenance and production costs by efficiently transporting materials along a linear path—whether moving them down, across, or upward. In addition to transportation, screw conveyors can also mix, agitate, or break down materials.

Because the screw mechanism cuts through materials during operation, it is not ideal for processing sticky substances like gels. Instead, screw conveyors handle dry to semi-dry bulk materials, both free-flowing and non-free-flowing. Common bulk materials include powders, sludge, dust, flakes, granules, boiler ash, and other loose products like seeds, food waste, wood chips, cereal, grain, fuels, process fluids, feed, and cement. More specific examples of processed materials include carbon black, caffeine powder, gypsum, ferric sulfate, cocoa beans, flour, garlic powder, animal feed, Epsom salts, vitamins, fiberglass, whey, and lead oxide.

Many industries rely on screw conveyors, including bulk handling, food and beverage, agriculture, chemical production, pharmaceuticals, construction, wood products, mining, minerals processing, oil and gas, pulp and paper production, rubber manufacturing, plastics production, stone cutting, glass manufacturing, concrete supply, environmental protection, and waste management.

Equipment Components

Screw conveyor systems typically consist of a spiral blade, also known as a helicoid flighting or flight, enclosed within a tubular casing or trough and mounted on a shaft. The spiral is coiled around the shaft and housed inside the tube. In most designs, the shaft and coil assembly, or shaft screw, is driven at one end and supported at the other. However, in the case of a "shaftless spiral," the screw is driven at one end and left free at the other. Due to this coiled design, screw conveyors are sometimes referred to asspiral conveyors.

Rotating screws, also called augers, are commonly fabricated from spring steel, carbon steel, or stainless steel. The enclosing tubes are typically made of steel, though alternative materials such as plastic or thermoplastic resin are also used depending on the application.

Operating a Screw Conveyor

To use your screw conveyor, begin by installing it in your system, whether it’s part of an exhaust drain, a wood chip machine, or another material handling setup. Ensure that you establish a proper feed system, as auger conveyors must be control-fed at the inlet. Many operators achieve this by integrating another conveyor or metering device, such as a screw feeder, tubular drag conveyor, chain conveyor, belt conveyor, or rotary valve.

Screw feeders are specifically designed to complement screw conveyors, providing precise control over the material flow rate. These feeders can be programmed to volumetrically meter material at a controlled rate, regulating both the amount processed per minute and the blade speed.

Notes on Safe Operation

Check the discharge port of the tube before and during operation to ensure it remains unblocked. If a blockage occurs, employ proper corrective measures, such as an interlocked switch, level detector, or safety coupling, to resolve the issue. A clogged discharge port prevents the screw from efficiently moving material, leading to a decline in system performance.

Ensure the casing size is appropriate for the material being conveyed. When processing bulkier or irregularly shaped materials like wood chips, paper waste, foam granules, or hard flakes, improper casing dimensions can cause material accumulation, forcing the auger to work harder while delivering suboptimal performance. Setting the screw in a way that allows it to apply force effectively will prevent material buildup.

Avoid frequent or unnecessary overloading of the casing cross-section, particularly in systems with hanger bearings. Excessive feed surges can lead to overfilling of the screw’s cross-sections, negatively affecting efficiency. Additionally, material should not bypass an open or intermediate outlet, as this can compromise product quality. To prevent this, consider an expanded outlet port with an intermittent flight arrangement. If frequent flight stoppages occur, adjusting the flight offset may help by allowing material to fall from the screw blade into the intended space more effectively.

Design and Customization for Conveyors

When designing screw conveyors, manufacturers take into account factors such as safety requirements, material characteristics (including size, flowability, density, flammability, roughness, and corrosiveness), application load volume, frequency of use, and other specific operational needs.

Using these considerations, they determine the appropriate materials, orientations, and optional features. For food processing applications, they often construct the trough and screw from food-grade rubber (UHMWPE). Similarly, when handling explosive materials, they may select anti-static UHMWPE for both the trough and screw. For general applications, screw conveyor machines are typically made from steel. Depending on the system’s material flow direction, manufacturers design screw conveyors in one of three basic orientations: horizontal, vertical, or inclined.

Screw conveyors are also highly customizable. While they are usually stationary, manufacturers can design portable models as well. Additional features may include a flexible discharge hose, wash-down section, mobile base unit, right-angle gear reducer, integral bag dump hopper, and control panel variations. Access and inspection ports can also be added near the outlet, allowing for easy monitoring and maintenance to ensure consistent and reliable performance.

Safety and Compliance Standards for Conveyor Equipment

The most important safety and compliance certification for a screw conveyor is a CEMA certification.

Conveyor Equipment Manufacturers Association (CEMA)
CEMA sets the industry standards for screw conveyor sizing and capacity calculations. These calculations account for factors such as the outside diameter of the screw, the outside diameter of the pipe, the pitch of the screw, and the trough loading. The final calculation determines the capacity in cubic feet per hour that the screw conveyor will move per revolution per minute.

Operators and buyers do not need to memorize these calculations. Most CEMA-approved screw conveyor manufacturers integrate these guidelines into their screw conveyor design software, ensuring precise and efficient system configurations.

Things to Consider When Purchasing a Conveyor

Because there are so many types of screw conveyors available, finding the right one can feel overwhelming. The best way to ensure you get exactly what you need is by working with a reputable screw conveyor supplier—but how do you find one? The simplest way is to use a trusted directory. Since you’re here, you likely already knew that, and now you’re looking for the next step.

Start by reviewing the list of high-quality providers we’ve compiled at the top of this page. Explore their capabilities, services, and areas of expertise, then narrow your choices down to a top three or four. With your specifications and requirements in hand, reach out to each supplier individually. Communicate your exact needs, paying attention not just to whether they can fulfill your request but also to their lead times, pricing, and delivery options. The ideal manufacturer will provide the best combination of quality, reliability, and cost-effectiveness while ensuring your order arrives on time and within budget.

Screw Conveyors Terms

Conveyor Screw
The driving force of a screw conveyor, consisting of a spiral flight fused to a metal pipe that rotates within the conveyor trough.

Discharge End
The point of exit for conveyed materials.

Double Pitch Screw
Conveyor screw containing two flights.

Flight
The metal spiral ridges or threads on a screw.

Flow
A product’s direction of travel on a conveyor.

Frame
The structure that supports the various components of the conveyor.

Hanger
Screw conveyor mechanism that aids in the correct alignment of the conveyor screws.

Helicoid Flighting
Screw conveyor flight that consists of a continuous metal strip configured in a spiral shape.

Horsepower
A measure of the time rate of doing work.

Inlet Opening
The point of entry for conveyed materials.

Liner
A barrier placed between a conveyor screw and a screw conveyor component, such as a trough, to reduce friction between the screw and trough.

Long Pitch Screw
Conveyor screw in which the pitch is greater than the diameter of the screw.

Motor
The machine on the conveyor that converts electrical energy into mechanical energy.

Multiple Ribbon Screw
Conveyor screw containing more than one ribbon flight along the length of the screw.

Paddle Screw
Conveyor screw containing blades attached at different angles, depending on the industrial application, used for mixing, blending, or similar applications.

Pitch
Distance between conveyor screw flights.

Ribbon Screws
Conveyor screws that contain sectional flighting and are used to prevent sticky conveyor materials from accumulating inside screw conveyor pipes.

Sectional Flighting
A screw conveyor flight consisting of individual bends or sections, fused together into spiral form. Sectional flighting is created by inserting a ring in a hydraulic press. It is a durable yet sometimes expensive type of flighting that is useful in tough applications, such as those in the construction and mining industries.

Shaft
The portion of the screw that provides support onto the flight to which it is fused.

Short Pitch Screw
Conveyor screw in which the diameter is greater than the pitch. Short pitches are used on inclined screw conveyors with slopes measuring 20° or greater.

Total Load
The total amount of material being conveyed at any particular moment in time.

Trough
A duct inside of which the screw is inserted and through which the materials are conveyed.

Variable Pitch Screws
Conveyor screws in which the pitch increases along the length of the screw.