This website uses cookies primarily for visitor analytics. Certain pages will ask you to fill in contact details to receive additional information. On these pages you have the option of having the site log your details for future visits. Indicating you want the site to remember your details will place a cookie on your device. To view our full cookie policy, please click here. You can also view it at any time by going to our Contact Us page.

Close

Minimising heat transfer risk

08 February 2021

Richard Franklin explains how adherence to five simple rules can enable food companies to operate heat transfer systems in such a way as to minimise risk, while promoting safety, reliability and efficiency. 

Thermal fluid systems are often used to transfer heat around food manufacturing plants for processing of products. However, when it comes to assessing the risks associated with food processing, the heat transfer plant component is often forgotten or misunderstood. From inefficiency, system failure and downtime, to explosions and loss of life, the risks of a poorly understood and poorly maintained thermal fluid heat transfer system can be catastrophic.

Rule one – make meeting and demonstrating compliance a minimum expectation: The efficient operation of thermal fluid systems promotes cost-effective process manufacturing. Usually, an efficient system is a safe one, incurring minimal risk of fire and explosion, achieving regulatory compliance and minimal insurance premiums. 

A total of 54% of all thermal fluid-related fires and explosions are said to be due to poor system maintenance (FM Global, January 2006, Heat Transfer by Organic and Synthetic Fluids). The risk of fire and explosion relates to the fact that thermal fluid systems’ operating temperatures are typically higher than the closed cup flashpoint of the thermal oil within – the minimum temperature at which, in the presence of a source of ignition (such as electrical sparks or pump failure) a fluid’s vapours will ignite.

To achieve cost-effectiveness of a thermal fluid solution, it is necessary to begin by identifying the relevant compliance requirements. Adherence to these – and possession of the relevant paperwork – will mean that should a safety incident take place, it is possible to demonstrate that you have been acting responsibly. Thermal fluid system compliance involves meeting requirements relating to system pressure (PED), flammable atmospheres (DSEAR) and operational and original equipment manufacturer (OEM) stipulations (PUWER). 

The next step is to take the rules which have been set to achieve compliance parameters and make the key performance indicators. Doing this makes compliance a tool to indicate the health of the thermal fluid system. As well as achieving compliance, this also achieves operational efficiently – and both will promote cost-effectiveness.

Rule two – make heat transfer fluid condition a critical indicator: The condition of thermal oil is critical to the performance, cost-effectiveness, safety and compliance of the thermal fluid system, and regular sampling and analysis are necessary to ensure that key criteria are met.  A thorough understanding of how the system works is also vital.

When selecting the best laboratory to undertake sampling, it is important to choose one capable of testing thermal oil both in terms of its performance as a heat transfer fluid and its safety.  

It is important to also be aware that some providers may have vested interests that can result in inappropriate analysis. The default advice of equipment vendors is often to suggest that purchasing new equipment instead of treating oil; alternatively oil may be blamed, rather than the equipment. Fluid suppliers can also be too quick to suggest the replacement of oil.

Important as regular fluid sampling is to ensure that your thermal oil is kept in good condition, it is essentially a reactive monitoring method, and the process manufacturers who get the best out of their heat transfer systems are those who understand how they actually work.  They use their knowledge to ensure that they run their thermal fluid systems to proactively protect the oil, promoting peak performance.  

Rule three – understand your layers of protection: It is important to be the master of your detection devices, not the slave! Understand the risks inherent within the heat transfer system, where they lie, what protective devices original equipment manufacturers (OEMs) have installed and crucially, what they protect you against. Do they meet your specific needs? If not, it will be necessary to adapt them so that they identify potential issues before they become problematic.

Rule four – apply the hierarchy of protection and detection rules to ensure that your entire system is protected: Thermal fluid operation is an integral part of the manufacturing system, and taking control of the former, can help protect the latter. A thermal fluid system should meet minimum standards of pressure and temperature and it should be closed-loop, with oil safely enclosed. Visual indicators and instrumentation devices should be checked and serviced regularly to ensure that they are working properly. 

The inline protection needs to protect the utility as well as the process. The release detection needs to be appropriate for the thermal fluid primary circuit as well as for the implications of the process and the primary assets. OEM supply rarely takes into account the process risk and the implications of a thermal fluid release and the subsequent fluid and flammable vapour.

Rule five – through training, ensure system integrity is maintained: Training is sometimes mistakenly perceived simply as a costly exercise necessary to meet health and safety compliance regulations. In fact, training is an investment, empowering entire teams not only to minimise risk, but to simultaneously maximise system performance.

A working understanding of thermal fluids and the risks they incur is rarely provided by OEMs, so it is vital that process manufacturers enlist the help of thermal oil specialists to provide the appropriate training to the key people.

They need to be aware of the in-built devices that enable the workforce to monitor the system’s key variables such as fluid and system temperature and pressure. They need to understand why the relevant parameters exist, how to monitor them to detect changes and crucially, what to do if changes occur – before the parameters are broken and the devices sound the alarm. Good training will also help process manufacturers to modify their detection devices to enable teams to monitor the key variables with greater efficiency.

In essence, training is as important as maintenance. It helps to create a culture of knowledge and curiosity that not only helps to prevent incidents, but that will also help promote system efficiency and so profitability.

Richard Franklin is managing director at Thermal Fluid Solutions.


Contact Details and Archive...

Print this page | E-mail this page