The benefits of preventative heat transfer fluid maintenance

Author : Clive Jones, Founder & Managing Director, Global Group

01 December 2022

In manufacturing facilities, proactive maintenance is vital to productivity – it can reduce the risk of downtime, reduce waste and improve efficiency. Condition monitoring and preventative maintenance is particularly important when working with thermal fluids as manufacturers must maintain production, protect staff and remain compliant with regulations.

Image: Global Heat Transfer

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Here Clive Jones, Managing Director of thermal fluid specialist Global Heat Transfer, explains how proactive thermal fluid management is the key to safe and efficient operations.

Manufacturers that require indirect heating processes for production routinely benefit from using thermal fluid systems. These systems can reach the high temperatures required for production without the high pressure needed to maintain heat when using other methods such as steam-based systems. The versatility of heat transfer fluids also enables manufacturers to select an oil designed specifically for the application, further increasing its efficiency.

Thermal fluids operate at high temperatures for long periods of time and will have a long lifespan and deliver great service when they are properly monitored and maintained. When working with thermal oils, engineers should be aware of the potential risks so that they know when and how to intervene.

Thermal oils can be heated to very high temperatures for extended periods during operations, which will, over time, cause the fluid to degrade – the rate of this process will accelerate if the fluid is not properly maintained. Fluid degradation can cause a fluid’s flash point, the minimum temperature at which the fluid’s vapours will ignite in the presence of a source of ignition, to drop, which will also lower the auto ignition temperature, further increasing the risk of an incident.

To improve safety when working with thermal fluids, manufacturers must adhere to local regulations. In the UK, The Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) of 2002 and the Explosive Atmosphere Directive (ATEX 137) outline the mandatory requirements for system maintenance. These regulations also lay out how manufacturers should evidence the prevention of fire or explosion where flammable materials are present.

The benefits of early intervention

Once a thermal fluid enters the system engineers are unable to visually monitor its condition and manufacturers will only be alerted to the condition of the fluid once it has degraded to an extent where it impacts production – for example, food cooks inconsistently or chemicals will not blend. At this stage it is often too late, and manufacturers must cease production to solve the problem and prevent damage, which can be time consuming and costly.

Image: Global Heat Transfer

When working with thermal oils, effective maintenance can ensure regulatory compliance, while reducing the risk of costly downtime and the risks associated with explosive atmospheres. By regularly monitoring and maintaining the fluid and system as part of a preventative maintenance programme, engineers can gain better visibility over operations and intervene earlier. Specialists should regularly sample the fluid when the system is hot, closed and circulating to gain an accurate representation of what is happening inside the system. A heat transfer fluid specialist can provide an analysis of the sample to give the manufacturer a complete understanding of its condition, so that manufacturers can take action and conduct any maintenance required.

For example, as part of a flash point management routine, engineers can limit the risks of degradation by installing a Light Ends Removal Kit (LERK). The LERK collects volatile light ends that cause the flash point to drop and drain them from the system, improving heat transfer efficiency and extending the lifespan of the fluid. Tracking the lifespan of the fluid also gives engineers the opportunity to intervene when they see signs of degradation, at which point they can dilute the fluid.

As well as monitoring fluid inside the system, how manufacturers store new oil before use can impact its lifespan. To save on space, some manufacturers store oil outside, but leaving the barrels or intermediate bulk container (IBCs) to the elements can impact oil quality. For example, if rainwater sits on top of containers and then the air temperature heats up, it may expand. Once it cools down, no matter if the container is open or sealed, it will contract, syphoning water from the top of the container and rendering the new oil unusable.

Similarly, when replacing oil, manufacturers should ensure that the labelling of waste oil and new oil is clear, as well as keeping them separate in the facility until it can be removed by a licensed company. Mislabelling could cause problems further down the line, such as topping up a system with old waste oil, which can accelerate degradation of the fluid already in the system, reducing heat transfer efficiency and increasing the risk of downtime.

System monitoring

The by-products of fluid degradation will impact the condition of the thermal fluid system, so proactive system maintenance is as important as fluid maintenance. Conducting regular system walk-rounds enables engineers to detect system issues before they impact production. During the inspection, engineers can monitor gauges to understand what is happening inside the system and look out for shaking pipes or slow production areas. Early intervention to solve these problems, by proactively cleaning, fixing or replacing parts, can increase uptime, reduce energy usage and lower maintenance costs.

Over time, parts of a heat transfer system will begin to wear, reducing overall efficiency. As well as concentrating on proactively maintaining core components of the system, manufacturers can prepare for when that part breaks down. Keeping critical spares on site, such as pump cartridges, parts for the heater or burner and spare fluid for topping up the system, can be integral to system management.

Clive Jones, Founder & Managing Director, Global Group

Around the facility

Just like fluid and system maintenance can improve productivity, making changes around the facility can also positively impact operations. In particular, environmental conditions, such as temperature or humidity, can affect how a heat transfer fluid system operates. Temperature control is important in processes that require indirect heat transfer as the operating temperature of fluid will impact product quality, for instance products may burn if overheated.

When controlling the temperature of the fluid and system, manufacturers must also consider how the heating process will impact the entire facility. If the system, or other machines in the facility, exceed their intended operating temperatures it can lead to equipment failure – electronic panels, for instance, can begin to fail once they exceed 40 degrees Celsius. Installing insulation across the system pipework enables engineers to better regulate temperature. Non-porous insulation, such as blown glass, works well in these applications because if the fluid leaks, the insulation will not absorb the fluid, reducing the risk of fire.

Good housekeeping is also integral to regulatory compliance when working with thermal fluids. Any small leaks or spillages should be cleaned up immediately to reduce the risk of slips or fires. As a part of a proactive maintenance strategy, engineers can install flange guards where leaks could occur. The guard ensures any fluid that leaves the system is a drip instead of a fine mist – which is far less flammable – increasing the visibility of a leak and reducing the risk of fire to keep workers safe. By having spill kits on site, engineers can then quickly remove the fluid and keep employees safe. Additionally, a clean working environment can greatly aid safety – clearing pathways of electrical wires or equipment not in use ensures that engineers can move safely around the facility.

In order to comply with industry regulations, manufacturers using heat transfer fluids must take proactive steps to assess potential risks and implement measures to eliminate them as much as possible. Thermal fluid is classed as a dangerous substance, but when monitored routinely and proactively managed, it will give great service for many years which is safer, more sustainable and financially viable for manufacturers.

About the author:

Clive Jones is the Founder and Managing Director of the Global Group of companies which he set up when he was just 17 years old. The Global Group of Companies has a range of business interests from the supply of hygiene and industrial consumables, storage and distribution through to oil and thermal fluids. Clive is heavily involved in business development, nurturing overseas partnerships and distribution agreements in new territories along with strategic planning and developing new ways of solving problems for heat transfer in manufacturing industries.