Conveying Screws for Sludge for Pyrolysis

Conveying screws for sludge for a pyrolysis plant fully manufactured by BEMA. The conveying screws were produced based on customer drawings, where BEMA has handled:

• Preparation of drawings for use in the manufacturing of conveying screws in the workshop
• Manufacturing of conveying screws
• Carrying out trial assembly after manufacturing
• Execution of FAT test runs in collaboration with the customer
• Handling transportation of the conveying screws to the final destination

What is a conveying screw?

• A conveying screw is a screw rotor enclosed within a housing. The conveying screw is equipped with a unit that drives the screw rotor – typically a gear motor
• A conveying screw is designed to transport material from the inlet to the outlet
• The housing of a conveying screw can either be a pipe – a tubular screw conveyor – or a formed trough – a trough screw conveyor
• Conveying screws transport all types of bulk materials
• Conveying screws can be manufactured in a wide range of steel types depending on the application or the properties of the material

What is special about these conveying screws for sludge in a pyrolysis plant?

• Sludge can be slightly aggressive. Therefore, the housings are at minimum made of stainless steel 1.4401 / AISI-316
• In the conveying screw where pyrolysis takes place, heat-resistant steel 1.4835 / MA-253 has been used to withstand high temperatures
• The conveying screw for steam drying is a triple screw, where three screw rotors operate in mesh with each other. This is particularly demanding in terms of manufacturing the screw rotors
• The installation consists of a total of 7 conveying screws, requiring extensive coordination during manufacturing

What tasks has BEMA carried out for these conveying screws?

• BEMA has handled the preparation of working drawings and advised the customer on various design questions
• BEMA has manufactured all conveying screws in its own workshop
• All welds have been carried out by workshop-certified welders
• All production processes have been documented and provided to the customer
• Performed complete assembly after manufacturing of the steel components. In this connection, BEMA provided workshop facilities for the customer, enabling them to install various process components
• Assisted the customer during all test runs for final customer approval

This project for the manufacturing of conveying screws for sludge in pyrolysis is part of the green transition in Denmark, where biochar is produced during the pyrolysis process. In this project, BEMA has been the company responsible for manufacturing the conveying screws based on designs from the customer’s process and mechanical engineers.

Read about another conveying screw project carried out by BEMA

FAQ: Conveying screws for sludge for pyrolysis

What are conveying screws used for in a pyrolysis plant?

Conveying screws are used to move sludge safely and in a controlled manner through the different process stages in a pyrolysis plant. They ensure stable material transport from inlet to outlet and are designed to handle both high temperatures and aggressive materials.

What materials are the conveying screws made of?

Since sludge can be aggressive, the housings are manufactured at minimum in stainless steel 1.4401 / AISI-316. In the pyrolysis zone, heat-resistant steel 1.4835 / MA-253 is used to withstand the very high temperatures in the process.

What makes the triple screw special?

The triple screw is used for steam drying and consists of three screw rotors operating in mesh with each other. This construction requires high manufacturing precision and ensures an efficient and uniform drying process.

What tasks does BEMA handle in the project?

BEMA manages the entire process: preparation of working drawings, manufacturing of conveying screws, certified welding, documentation, trial assembly, FAT test runs, and support to the customer during installation and approval. This ensures a complete and reliable solution.