Modern Mining

HYDAC seeks SADC expansion of IIot-powered oil lubricration systems

HYDAC South Africa is scaling up its oil-based lubrication systems in the southern African mining industry. Setting the company apart in this field is the integration of sensors and IIoT in its offering to enable remote diagnostics, thus being more proactive in servicing customers, especially those operating in remote parts of Africa, writes Munesu Shoko.

Having set up shop in South Africa some 13 years ago, HYDAC South Africa, part of Germany headquartered HYDAC International, has over the years been on a drive to expand its footprint and offering into new markets and indus-try sectors. Traditionally renowned for its hydraulic accumula-tors and filtration systems, the company has in the past five years broadened its offering with oil-based lubrication systems, with a specific focus on turnkey project solutions for the mining sector. Central to this approach is the integration of the Industrial Internet of Things (IIoT) in its oil-based lubrication units, ush-ering in a new era in this sector. “Having initially focused on component sales, we have grown our project business significantly over the past five years, with initial focus on South Africa,” says Tinus Vermeulen, national project sales man- ager at HYDAC South Africa.

To support this growth, the company has recently expanded its footprint in South Africa with the addi- tion of operating branches in Durban and Cape Town, complemented by resident sales engineers situated in different parts of the country, including Bloemfontein, Richards Bay and Gqeberha (formerly Port Elizabeth). In addition, the engineering team has been increased to support customers with regards to the design, manufacture and project management of the HYDAC systems.

The focus now turns to the Southern Africa Development Community (SADC), says Vermeulen, where the company is establishing a strong footprint in big mining markets such as the DRC and Zambia. “We have recorded some notable successes in the DRC in the past year, making a breakthrough on some of the large mines in the country,” he says. “We seek to expand our oil-based lubrication sys-tems in these mining markets. With the integration of IIoT, we believe we have a unique value proposition for the mining sector, where downtime is out of the question.

In principle, a lubrication unit isn’t neces-sarily a complicated piece of equipment, but the functions that we offer with it are critical in ensuring that mining equipment, which generally runs at high duty cycles in adverse envi-ronments, operates at optimum conditions (temperature, water content and dirt),” explains Vermeulen.

HYDAC engineer Dustin Pereira, tells Modern Mining that the lubri-cation market has traditionally been dominated by one or two strong players. The situation has, however, changed in the past 10 years with the influx of many smaller suppliers. It is how-ever critical to select quality products when designing and manufacturing the lubri-cation skids as any downtime can affect the user’s outputs, stresses Pereira.

HYDAC’s offering
HYDAC South Africa is looking at supplying lubricat-ing oil to moving machinery including gearboxes, bearings and pinions, among others. The viscosity of the oil is usually elevated to supply a lubricating film at elevated temperatures.

HYDAC develops oil-based lubrication systems. Shown here is a hydraulic powerpack for a white metal bearing jacking and lubricating system.

Tinus Vermeulen, national project sales manager at HYDAC
South Africa.

Izak Lombaard, project engineer at HYDAC South Africa

Dustin Pereira, engineer at HYDAC

In order to design a successful lubrication system, says Pereira, it is imperative that oil cleanliness and contaminant levels are maintained within a tight ISO tolerance rating. The equipment requiring lubrication is kept within a strict temperature range to maximise efficiencies and prevent breakdown of the lubrication oil. 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.

“When it comes to the health status of machinery, there is need for early warning mechanisms to prevent serious damage to plant equipment. HYDAC has a line of products for conditioning and monitoring of lubricating systems on various ranges of plant equipment. For example, our screw pumps allow for large viscosity oils and large flow rates to be pumped without cavitation, while offering a higher dirt tolerance when compared with various other positive displacement pumps. These pumps run quietly and with low ripple and can incorporate internal pressure bypass valves to protect equipment from overpressure spikes,” explains Pereira.

Where slipper pads require jacking, adds Pereira, HYDAC also has a range of high-pressure multioutlet pumps capable of providing each pad with its own supply of oil, and not rely on problematic flow dividers. Each line can be individually monitored and settings adjusted for drive end and non-drive end jacking force requirements.

Oil conditioning
Oil conditioning is key to lubrication systems, and is therefore one of the key focus areas for HYDAC.

Pereira explains that the oil in most applications is only gravity fed back to a sump/reservoir. This oil therefore does not have the effective head or pressure to allow for efficient filtration or cooling. Consequently, a reservoir must be designed to allow for oil to return under gravity and for conditioning before feedback to the plant equipment. Some key elements in the conditioning leg comprise the following:

Reservoir/sump design:
High performance systems may require the oil to return to the reservoir through a basket strainer in order to remove any larger particles that may be picked up during equipment operation that can cause damage to the lubrication system. The basket strainer is made of stainless steel and is washable/serviceable. The reservoir design, stresses Pereira, is key to allow for settling of the oil. It must have compartments to allow for the settled particles to be removed during maintenance. The settling compartment is therefore separated into an intermediate section to allow for oil to be circulated through a large capacity filter and heat exchanger, before returning the conditioned oil to the ‘clean’ compartment.

The clean compartment ensures that the jacking pumps are exposed to the filtered oil before supplying it back to the bearing. The reservoir allows for monitoring of the oil level, temperature and cleanliness.

Conditioning of the oil:

This is a key process in the lubrication process. Plant equipment operates at high duty cycles and in most instances under difficult conditions, whereby wear particulates are washed away by the conditioning oil. To ensure the longevity of the moving components, the lubricating oil must be replenished with fresh, clean and cool oil. To remove particulates from the oil, high efficiency filters with a large dirt holding capacity are installed to remove the dirt from the high viscosity oil throughout the operating temperature range.

“HYDAC has a full range of low-pressure highcapacity filter housings and elements to achieve conditioning of the high viscosity oil to a pre-determined ISO cleanliness level, incorporated with the inline low and high pressure filter assemblies, both singular and duplex. In fact, we have a full filter portfolio available. Intelligent electrical clogging indicators allow for cold start-up bypass. This in turn allows for a cost effective design for the ideal operating range of plant equipment. Smart sensors also give feedback on the filter cleanliness capacity trends for predictive maintenance applications,” explains Pereira.

HYDAC’s CSM 1000 metallic contamination sensor, an online condition monitoring system for the continuous measurement of solid particle contamination in hydraulic and lubrication fluids.

HYDAC’s HFT 2100 flow transmitter is used for monitoring the flow rate of systems with viscous fluids.

Temperature control:

This is one of the important factors in the process. Many gearboxes and moving machinery are sized based on thermal capacity and heat dissipation properties. A gearbox may have to be oversized for an application based on the thermal capacity rather than the performance of the gears, and this may make the selection impractical or unsellable. Therefore, removing excess heat from moving machinery is a key feature of lubrication systems.

HYDAC offers 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 are able to integrate various electric motor fan drives, allowing these units to be adapted for various voltages and frequencies based on the client’s needs. “Thermo-bypass valves can be integrated into systems whereby efficient cooling can be supplied all year round, regardless of the fluctuation in the cooling media temperature (within limits). Therefore,
oil from the reservoir/sump is cooled through the conditioning leg and returns to the clean chamber of the reservoir for the supply pumps delivery to plant equipment,” says Pereira.

System intelligence
Given the shortage of skills on mines in some countries, Pereira says system intelligence is the next big thing in lubrication. System intelligence, Industry 4.0 and predictive maintenance can be achieved through the strategic integration of a range of HYDAC sensors throughout a lubrication system. Simple feedback from key features is achievable with HYDAC sensors such as flow rate transmitters and switches, pressure sensors and temperature sensors. These are all capable of giving feedback to control systems of both return oil from plant equipment and the supply of conditioned oil into the field.

The feedback from these sensors can give trip commands or sequence additional equipment. With HYDAC, it can be achieved from CAN open sensors, ATEX and SIL rated sensors. “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. Sensors in the return line compartment can pick up the amount of metallic ferromagnetic particles that return from gearboxes and may also trend wear characteristics on the gears where setpoints may be programmed to signal maintenance requirements. Aqua-sensors may be installed to monitor the ingress of free water molecules into the gearbox or bearings – this may again point to issues with plant equipment breathers or labyrinth seals, among others,” says Pereira.

Once the ingress of moisture is found, HYDAC rental equipment can be installed to remove any dissolved water particles within the system.
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. “All of these sensors may be integrated into cloud setups with a dashboard development, allowing remote access by specialists capable of identifying mechanical issues before they become serious breakdowns,” says Pereira.

Enter IIoT
The Industrial Internet of Things (IIoT) is unleashing enormous value in plants around the world. IIoT, involving real-time sensing and predictive maintenance, is viewed as an easy win for lubrication. With data being the new currency for businesses, says Izak Lombaard, project engineer at HYDAC South Africa, IIoT is quickly moving from being optional to a requirement and will soon become an invaluable
part of business operations in order to gain a competitive edge and remain one step ahead in tough economic times. Explaining IIoT, Lombaard says it is basically the IoT (Internet of Things) at an industrial scale.

IoT is a term that refers to all things that get connected to the internet, he says. IoT was pioneered in home automation, allowing users to remotely control devices in the home like turn the lights on, turn the thermostat up and control a robot vacuum cleaner, among others- demonstrating the significant role internet-connected devices can play in the modern lifestyle.

On an industrial scale, says Lombaard, industrial ‘things’ such as automated controllers (PLCs and electronic controllers), individual devices and sensors, as well as other items such as cameras, vehicle fleets and telephone systems, can now be connected to the internet. “Once connected to a local network, these components can individually communicate with each other, allowing for a large information network. This provides us with continuous information from the devices. This info is on demand, extremely detailed, live or historical, follows trends and predicts maintenance and failure. All this can be done remotely. The remote part is very important because we can
now quickly assist a client who is far away from our Johannesburg office without having to send a technical person to site, for example, up in Africa,” explains Lombaard.

How it works
HYDAC installs an internet gateway on a system, for example a lubrication unit. “To connect to the internet, we can use a mobile SIM card, WiFi or Ethernet connection,” says Lombaard. The system can have an existing network (PLC or controller) or only a few analogue and digital sensors without any controller. The existing network can then be accessed from anywhere in the world via a VPN connection. The
VPN allows HYDAC to connect to the gateway. The data and information from the devices connected to the gateway is stored in the internal memory of the gateway. This information can also be forwarded to a local server or the cloud. “We can also create a web server on the gateway.

This web server can host several custom designed web pages. The web pages can be designed to show information such as live sensor values, historic trends and alarm & error messages, to name a few,” says Lombaard. “We can also use the web pages to change values on the system – set points can be changed, systems can be started and stopped remotely.” Automated emails can be configured on the gateway, and reports at set intervals. Emails can be based on sensor values. Web pages can be accessed from any device that is capable of browsing the internet. This includes computers, mobile devices, tablets or smart TVs at home.

“Most systems are already fitted with digital and analogue sensors which can connect to the gateway which HYDAC installs. The additional hardware cost to get a system connected to the internet is very affordable when compared to the early failure of equipment,” explains Lombaard. “The real benefit can be seen if you compare the cost to implement IIoT on a system to that of a single flight and accommodation for a technician or engineer to visit a site for a few days. COVID-19 has also cast the spotlight on the importance of these systems, given the difficulties of travelling to sites during lockdowns,” concludes Lombaard.