Conveyor screws Manufacturers online

Conveyor screws consist of a spirally wound screw helix that moves bulk materials such as grain, flour, sand, granulates or sludge along a trough or pipe from the inlet to the outlet.

They are the central components of screw conveyors. Screw conveyors are used in numerous applications, from agriculture to the food industry and heavy industry.

Here is a brief overview of how conveyor screws work, the materials and thoughts on screw geometry and rotational speed, plus details of their use in screw conveyors:

How conveyor screws work:

By rotating, the conveyor screw moves the material along a closed tube or an open trough.
Conveyor screws can be operated horizontally, vertically or inclined to move material over different distances and heights.

Materials of conveyor screws:

The choice of material for a conveyor screws depends on the material being conveyed and the environmental conditions.

1. For abrasive materials such as sand, gravel or cement, the screw conveyor should be made of wear-resistant material. Hardened steel or bimetallic coatings are often used here, which significantly extend the service life of the screw.
2. In environments that convey chemically aggressive or moist materials, stainless steel or special corrosion-resistant coatings are required to protect the screw from damage.
3. In the food and pharmaceutical industries, the material of the screw must be food-compliant; stainless steel is generally used here, which is easy to clean and meets hygiene requirements.

Screw geometry and rotational speed of conveyor screws:

1. The screw profile (the shape and pitch of the turns) should be matched to the material and the conveying process. Materials with different flow properties, such as powders, granulates or sewage sludge, require adapted screw shapes.
2. The speed of the screw influences the conveying speed and the conveying capacity. Too high a speed can damage the material, too low a speed can lead to blockages. The speed must be adjusted according to the material properties and the area of application.

Use of conveyor screws:

1. Transportation of bulk materials:
Conveyor screws are used to transport bulk materials such as grain, flour, cement, coal or plastic granules. They can efficiently transport the material in small or large quantities over short to medium distances.

2. Dosing and control:
In addition to transportation, conveyor screws can also be used for dosing materials. This is particularly important in the chemical and food industries, where precise quantities of material need to be conveyed or mixed.

3. Conveying under special conditions:
Conveyor screws are used in environments where other conveying methods, such as belt conveyors, do not work efficiently. They are ideal for use in confined spaces, under high temperatures or in dusty or potentially explosive environments.

Conveyor screws are the key components of screw conveyors used for the efficient and continuous transportation of bulk materials in various industries. Their robustness, flexibility and ability to adapt to different conveying conditions make them a popular choice in many applications.

Here is an overview of the most important points to consider when buying conveyor screws:

When purchasing conveyor screws, there are a number of technical, economic and quality aspects that should be carefully considered to ensure optimum performance and longevity

• The material to be conveyed largely determines the material and coating of the conveyor screw:
• Corrosion resistance: depending on the conveyed material, e.g. food, chemicals or moist materials, stainless steel e.g. V2A or V4A or coated steel is required.
• Abrasion resistance: For abrasive media such as sand, glass or minerals, hardened steels or wear-resistant coatings such as hardfacing or plastic coatings are recommended.
• Food and hygiene standards: For applications in the food or pharmaceutical industry, materials must be FDA-compliant or approved in accordance with EU directives.
• The screw geometry and design are further determining factors:
• Screw diameter: Matched to the desired conveying capacity and the existing trough.
• Pitch (flight height): Dependent on the conveying speed and material properties.
• Shaft or shaftless design: Shaftless screws are suitable for fibrous or sticky materials, while shaftless screws are more stable.
• Left or right-handed: Must match the direction of rotation of the drive.
• Single or multi-start auger: Multi-start augers increase the conveying capacity in confined spaces.
• The accuracy of fit and the interfaces should also be taken into account:
• Length and connection: exact dimensions so that the auger fits into the existing conveyor.
• Connection to shaft coupling and bearing: Must match the existing flanges and drive shafts.
• Tolerances: Precise manufacturing is crucial for smooth running and service life.
• Torque absorption: Screw must be designed for the maximum torque of the drive.
• Bending stiffness: Risk of deflection with long lengths → Plan for additional support bearings or a stronger shaft.
• Wear reserve: Thicker bars for highly abrasive conveyed material.
• The surface quality should be matched to the conveyed material:
• Smooth or textured: Smooth surfaces reduce sticking, e.g. with moist or sticky goods.
• Polished (Ra value): Important for hygienic areas to minimize cleaning effort.
• The operating conditions play a decisive role:
• Temperature resistance: Adapt for hot media or thermal processes.
• Chemical resistance: Against aggressive substances, alkalis, acids.
• Moisture: Rust protection or stainless steel for moist media.
• Responsible purchasing also keeps an eye on the economic aspects:
• Life cycle costs instead of pure purchase price: High quality can significantly reduce downtimes and maintenance costs.
• Availability of spare parts: Standardized screws are easier to procure, while custom-made products extend delivery times.
• Service and support: Suppliers should offer technical advice, installation assistance and aftercare.
• Standards and certifications play an important role in use, especially in the food industry:
• Hygiene regulations for food applications (EHEDG, FDA).
• Machinery Directive (EU): Observe for safety-relevant parts.
• DIN standards for screw conveyors and materials.

When purchasing conveyor screws, it is not only the price that matters, but also the careful matching of material, geometry, wear protection and interfaces to the respective application. Those who precisely define the chemical, mechanical and hygienic requirements and pay attention to precision and quality will significantly reduce downtime, maintenance costs and failures. Close coordination with the manufacturer and consideration of standards and spare parts availability are crucial to ensure a durable and economical solution.

Conveyor screws can be purchased from various suppliers. Comprehensive information about manufacturers and suppliers of Conveyor screws from all over the world can be found on Exportpages.