System intelligence in Oil-based Lubrication Systems for Mining Projects

HYDAC South Africa’s sensor-based lubrication systems are highly regarded in the lubrication niche market in Southern Africa’s mining sector. The addition of system intelligence has turned the lubrication systems into a tool that can be deployed in remote monitoring of moving equipment, enabling effective predictive maintenance. Eventually, end-users can benefit through reduced damage and downtime, as well as increasing productivity.

Currently, mines in Southern Africa (Southern Africa Development Community (SADC) countries are ramping up production. HYDAC South Africa recognises that it is essential for mining companies to ensure that their moving machinery, which operates at high duty cycles and under difficult conditions, performs optimally at all times in order to sustain the momentum. For this reason, the company has introduced a solution that involves the integration of Industrial Internet of Things (IIoT) and sensors to its flagship oil-based lubrication units to enable remote diagnostics of components of equipment, including but not limited to gearboxes, bearings and pinions. The integration allows for predictive maintenance, which reduces downtime, guaranteeing equipment availability and increased productivity.

Ushering a new era

With the ground-breaking launch, HYDAC South Africa’s National Project Sales Manager, Tinus Vermeulen, says HYDAC is excited to be ushering mining companies into a new era in which oil-based lubrication systems perform a function beyond merely oiling machinery. He acknowledges that there is nothing complicated about oil-based lubrication systems. However, the integration of IIOT and sensors brings the certainty of equipment availability at all times – something that the market is urgently in need of.

In actual fact, the launch of system intelligence has been perfectly timed. While HYDAC’S lubrication units have been consistently meeting industry’s expectations (even exceeding expectations), in the past ten years, the entry of small players has increased the range of products available to clients. So, uniquely, what sets HYDAC’s IIOT integrated lubrication solution apart from other  lubrication units is that it provides the client with increased scope of functions. “Our value proposition is that what we offer with IIOT integrated lubrication units is critical in ensuring that mining equipment, which generally runs at high duty cycles in adverse environments, operates at optimum conditions in terms of temperature, water content and dirt),” explains Vermeulen, envisaging mining companies in the SADC region benefiting more from the strategic integration of a range of HYDAC sensors in the lubrication system.

Strategic integration of sensors

System intelligence, Industry 4.0 and predictive maintenance can be realised through the strategic integration of a range of HYDAC sensors – such as flow rate transmitters and switches, pressure sensors and temperature sensors – throughout a lubrication system. Using historic and live information, HYDAC sensors are capable of giving feedback to control systems of both return oil from plant equipment and the supply of conditioned oil into the field. Feedback on the condition of returning oil from the sensors can indicate the health status of the plant equipment, which can be used as an early warning mechanism for predictive maintenance. Based on the result, proactive measures can be taken to prevent serious damage and downtime to equipment.

Wider scope of capabilities

The strategic integration has created a solution with a wider scope of capabilities. HYDAC’s CAN open sensors, ATEX and SIL rated sensors are able to gather vital data on issues such as filter clogging, wear, water and contamination, which is utilised to map out predictive maintenance.

• Filter clogging 

The filter clogging sensors can trend wear and serve as an early warning, when a spike of contaminants is recovered from the field with the lubrication oil.

• Wear

Sensors in the return line compartment can pick up the amount of metallic ferromagnetic particles that return from gearboxes, besides trending wear characteristics on the gears where setpoints may be programmed to signal maintenance requirements.

• Water ingress

Aqua-sensors may be installed to monitor the ingress of free water molecules into the gearbox or bearings, relating to issues with plant equipment breathers or labyrinth seals, among others. Once the ingress of moisture is found, HYDAC rental equipment can be installed to remove any dissolved water particles within the system.

• Contamination

Contamination sensors can give real-time feedback on the lubricating oil’s ISO cleanliness levels. Trending this may serve as an early warning signal for ingress of foreign particles into systems from wear or damaged parts. Returning oil is capable of indicating the health status of the machinery and can therefore be used as an early warning mechanism for predictive maintenance, thus preventing serious damage and downtime to plant equipment.

A holistic system health matrix

Usually, the condition of the returning oil is a direct indication of the health of the moving machinery. It serves as an early warning signal for ingress of foreign particles into systems from wear or damaged parts. “Generally, by tracking and trending metrics from sensors, a holistic system health matrix can be created. Then, the data gathered can allow the system integrators to build a preventative and predictive maintenance model into the system intelligence of the gearbox/bearing/crusher lubrication system are able to identify changes timeously and take appropriate action,” Vermeulen elaborates.

Remote access

Conveniently, all of HYDAC sensors may be integrated into cloud setup with a dashboard development, allowing remote access by specialists capable of identifying mechanical issues before they become serious breakdowns. The user can connect to the lubrication unit from anywhere in the world using either a mobile sim, Wi-Fi or Ethernet connection. Therefore, key metrics can easily be monitored remotely.

Furthermore, the benefit of IIOT integration is more evident when comparing the system access and information it provides to the alternative of flying an engineer to a site in a remote country. Onsite user intervention can therefore be minimised to the execution of basic manual tasks like changing a filter element. It makes lubrications handling complicated lubrication tasks less skills-intensive.

Investment in increased plant availability

Farsighted, the team at HYDAC South Africa see system intelligence in lubrication as the next big thing in a world in which preventative maintenance has become more relevant than ever. “The user is not buying a smart lubrication system, but rather increased plant running and production time,” Vermeulen assures potential clientele about investing in system intelligence enabled- lubrication systems.

As part of the HYDAC International Group, HYDAC South Africa focuses on the SADC region, which includes all of the Southern African states up to the DRC and Tanzania, as well as the Islands of Madagascar, Mauritius and the Seychelles off the East Coast of Africa.

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HYDAC’s turnkey lubrication solution

HYDAC strives to produce premium custom-made oil-based lubrication systems for moving equipment that always prevail when subjected to tough conditions in harsh environments.  While the addition of system intelligence has created a buzz, the company’s technical team remind potential clientele in the Southern African mining sector that the company offers a turnkey oil lubrication solution.

The company provides a turnkey lubrication solution, which encompasses designing and manufacturing of the system, The company’s lubrication systems are specifically engineered to maintain oil cleanliness and contamination strictly within the ISO tolerance rating to minimise downtown. “The oil provides a lubricating film to these moving items and conditioning of the oil reduces the thermal loading of the piece of equipment, thus extending the life of the machinery,” says Vermeulen, underlining the significance of meticulousness in the design and selection of products to be used in manufacturing to improved oil conditioning and temperature control.

The design   

The design by engineers at HYDAC is done to the specific piece of machinery’s specifications, taking into account the operating environmental conditions. The advanced tank design and layout integrating high-capacity filtration allow for a high level of system availability.

The reservoir is used for monitoring of the oil level, temperature and cleanliness. That is why a suitable reservoir design is key.

There are two common elements that are catered for in the design in respect of high-performance systems. Firstly, in most applications, oil settles to the sump/reservoir under gravity, and, secondly, the need for removal of settled particles during maintenance.

Relating to the issue of gravity, a reservoir must be designed to enable the oil to return to the reservoir (settle) under gravity for thorough conditioning before feedback to the plant equipment. Typically, a steel basket strainer, which is washable, is incorporated into the reservoir design. The aim is for the oil to go through a steel basket strainer to remove large particles that may have been picked and can cause damage to the lubrication system.

Additionally, the design must have an intermediate and settling compartments to allow for the settled particles to be removed during maintenance. In the settling compartment, the oil is circulated through a large capacity filter and heat exchanger, and after conditioning returns to the ‘clean’ compartment. Finally, the clean compartment ensures that the jacking pumps, which are screw positive displacement, are exposed to the filtered oil before supplying it back to the bearing. Screw pumps are specified as they are able to pump large viscosity and large flow rates without cavitation, giving the lubrication systems a higher dirt tolerance when compared with various other positive displacement pumps. These pumps can incorporate internal pressure bypass valves to protect equipment from overpressure spikes.

Conditioning of the high viscosity oil

HYDAC recognises conditioning of the high viscosity of the oil to a predetermined ISO cleanliness level for longevity of the moving components as a key process in the lubrication process. For this reason, the lubricating oil must be replenished with fresh, clean and cool oil/ low-pressure high-capacity filter housings and elements. To remove particulates from the oil, high efficiency filters with a large dirt holding capacity are installed throughout the operating temperature range. HYDAC has a full range incorporated with the inline low- and high-pressure filter assemblies, both singular and duplex. Smart sensors also give feedback on the filter cleanliness capacity trends for predictive maintenance applications.

Temperature control

Many gearboxes and moving machinery are sized based on thermal capacity and heat dissipation properties. Thus, they need to be kept within a strict temperature range to ensure efficient operation and protection of various temperature sensitive components.

By controlling the oil temperature and keeping it within a strict range, this can be realised. Accordingly, HYDAC is able to realise temperature control through the use of a full range of well-defined heat exchangers capable of dissipating large heat loads with various media, including air, water, sea-water and other fluids. The air/oil heat exchangers can be adapted for various voltages based on the client’s needs.

In the end, the client is offered the best possible lubrication solution tailored for the destined site. “The user is not buying a smart lubrication system, but rather increased plant running and production time,” Vermeulen reiterates in conclusion.