Horizontal screw conveyors for cutting material

Horizontal screw conveyors for cutting material manufactured for an off-shore application. BEMA has designed and manufactured 2 pcs. horizontal screw conveyors to transport cutting material from the shaker to an outlet system on a drill rig. The 2 horizontal screw conveyors have a length of app. 23 meter.

What is the key points for screw conveyors for off-shore?

1. Specific design rules and related off-shore specification must be obeyed
2. Design has to meet a rough environment off-shore
3. Placement of the horizontal screw conveyors are often in ATEX zones
4. Documentation requirements for the screw conveyors are comprehensive

In the actual application the ATEX demands for electrical equipments in the ATEX zone is: II2G Ex eb IIB T3 GB

ATEX: This refers to the European Union directive for equipment used in potentially explosive atmospheres.

II: Equipment group. In this case, it’s suitable for all above-ground explosive environments.

2G: Device category for gas. It indicates that the equipment is suitable for areas 1 and 2.

Ex eb: Type of protection. “eb” stands for increased safety.

IIB: Gas group. It specifies the type of gas (in this case, IIB).

T3: Temperature class. The equipment can operate safely up to a maximum surface temperature of 200°C.

GB: Geographical area. It’s relevant for the European Union and EFTA countries.

During the design phase, BEMA has clarified the ATEX requirements in cooperation with the customer, and ensured that all used electrical equipment confirms to the specifcation.

Follow this link for another ATEX approved solution

Other key design elements for the cutting screw conveyors

1. The screw rotors are supplied with intermediate bearings to ensure that they are self carried
2. A chain coupling between the gear box and the screw rotor is applied for easier maintenance on-site
3. Support cribs delivered with the screw conveyors for smooth and fast installation off-shore

See another example of a cutting screw conveyor here

What documentation level can be deliver for our screw conveyors?

1. EC-conformity declaration
2. ATEX approval documentation for our screw conveyors and used components
3. Machine drawings with part lists
4. User manuals and other relevant technical manuals
5. Material certificates – we have incoporated a material control system in our quality system
6. Welding towards own WPQR’s
7. Welders certificates
8. FAT test reports
9. Test certificates on demanded tests during the manufacturing

In BEMA we have an experienced design department that support our prodution department with drawings and descriptions to ensure that we can meet the requirement towards the screw conveyors.

FAQ – Horizontal screw conveyors for cutting material

What are these horizontal screw conveyors used for?

They are designed to transport cutting material from the shaker unit to an outlet system on an offshore drill rig. Each conveyor is approximately 23 meters long and built to operate reliably in harsh offshore environments where exposure to vibration, salt, and heavy wear is common.

What ATEX requirements apply to this installation?

The electrical equipment used in this application must comply with II2G Ex eb IIB T3 GB, meaning it is suitable for gas zones 1 and 2, uses increased‑safety protection, meets gas group IIB, and can operate safely up to 200°C. BEMA clarified all ATEX requirements with the customer and ensured full compliance.

What design features make the conveyors suitable for offshore use?

The screw rotors include intermediate bearings so they are self‑supporting over the long distance. A chain coupling between gearbox and rotor allows easier maintenance, and support cribs are supplied to ensure fast and smooth installation offshore. These features increase durability and serviceability in demanding conditions.

What documentation can BEMA deliver for these conveyors?

BEMA provides extensive documentation, including EC‑conformity declarations, ATEX documentation for conveyors and components, machine drawings, user manuals, material certificates, welding documentation, FAT test reports, and any required manufacturing test certificates. This ensures full traceability and compliance.