Sunday 6th Dec, 2020

Harvesting the benefits of linear actuators

As part of a trial, CBH Group has installed linear actuators across five key sites in its network, resulting in a significant boost to its efficiency and reduced labour costs.

As part of a trial, CBH Group has installed linear actuators across five key sites in its network, resulting in a significant boost to its efficiency and reduced labour costs.

Every year, millions of tonnes of grain are grown and harvested across the wheatbelt region of Western Australia. In order to export them, a vast network of railways and storage facilities are required.

Established in 1933, the CBH Group is Australia’s largest co-operative and biggest grain exporter. It currently receives and exports more than 90 per cent of the state’s grain harvest across more than 120 sites dedicated to storing, handling and transporting it.

CBH operates a rail fleet dedicated to the most efficient methods of moving grain from its receival sites to export at its four port terminals.

In February, the co-operative announced it would invest more than $150 million into its infrastructure and add more than 800,000 tonnes of storage and associated inloading and outloading equipment.

Jason Zuglian, CBH Project Engineer – Electrical, says finding ways to reduce maintenance and streamline operations is vital to remaining competitive in the global grain market.

Gate valves are predominantly used across CBH systems to regulate flow of grain through its receival systems. Gate valves across the network have been typically actuated with a motor, gearbox and chain drive arrangement that requires independent control devices such as limit switches. This increases the complexity of the design and the potential for increased failure points thought the system.

To simplify this arrangement, Danish equipment manufacturer LINAK (short for Lineær Aktuator) reached out to CBH and offered a potential solution using electric linear actuators. These have been used in other industries to control actuated systems for a wide variety of solutions.

The company, designs and manufactures full actuator systems for smooth and reliable movement in diverse environments.

LINAK’s LA36 actuators are able to convert rotational motion in low voltage DC motors into linear push/pull movements, providing safe and clean movement with accurate motion control. They were designed for applications involving tilting, lifting, pulling or pushing with thrusts of up to 10,000 newtons.

Mr Zuglian says CBH began trialling the technology on a handful of sites to see how it would integrate with the current systems and infrastructure.

“The actuators incorporate integrated limit switches which give end of stroke positioning. There are also options to include multi-position sensing that can inform the exact position of the actuator allowing increased control,” he says.

“The control over the actuator position allows the plant to be operated more effectively.”

The actuators have been used on slide valves or knife gates, sampling systems and loading chutes. Each can also be incorporated into a programmable logic controller for additional connectivity in the network and enhanced precision.

LINAK’s design also reduces the amount of moving parts. There are no sprockets, chains or guards that can act as potential pinch points, which helps improve safety and make installation significantly easier.

Mr Zuglian has installed around 100 actuators across CBH’s project sites and says the installation process is much simpler. Installation only requires two mounting plates and two cables to be bolted into place, as opposed to a gearbox and motor with foot mounts and mounting plates.

“The ability to replace any faulty components is relatively quick and easy and means we now have access to speed control and real time positioning,” he says.

“Some manual valves are located in confined spaces and explosive environments due to dust, but because the actuators are easy to retrofit and automate, they can remove the need for operators in potentially hazardous areas.”

The LA36 is one of LINAK’s most powerful actuators and has been designed to operate under extreme conditions. It offers almost no maintenance and can provide a long service life. Each actuator is IECEx and ATEX certified, allowing use for dusty, explosive environments.

Mr Zuglian says during the actuator trial, outloading turnaround times were faster, which had flow-on effects through the supply chain.

“Timeframes for loading and unloading were reduced,” he says.

“Improvement of our engineering design is a continuous process and this small element is a good example of how technology is being incorporated in our systems to increase efficiency.”