~Understanding heat transfer systems saves time and money~
There are some paintings that reveal more detail the longer you look at them. At glance you may see a countryside landscape, then you spot that the scene makes a face. Optical illusions both confuse and intrigue, but other objects or systems can also be more detailed than they first appear. If manufacturers look in more detail at their heat transfer systems, they may find problems they could prevent.
In this article, Dave Dyer, technical sales engineer at heat transfer specialist Global Heat Transfer, discusses how a detailed understanding of a heat transfer fluid system can help manufacturers maintain efficiency and prevent costly downtime.
Thermal fluid systems are used to provide indirect heat in production in a number of industry sectors including pharmaceuticals, food and chemical processing. Thermal fluid systems transport thermal fluid through a production line to perform actions such as processing chemicals, deriving electricity or cooking food. Many manufacturers run their plants using this system to optimise productivity.
Manufacturers must ensure their plants run safely and efficiently to meet equipment regulations. However, in many ways, regulatory compliance is only a minimum in terms of safety checks and maintenance. Plant managers can inspect their systems to prevent system problems with proactive and early maintenance. In order to do so, manufacturers can draw from their understanding of the system.
The better the operator’s understanding of the system, the more able they are to spot issues early and prevent, costly downtime. The plant manager is not the only person that needs to understand the ins and outs of the system though. Staff should be trained across the board, to ensure that there is always a member of staff on site that is capable of tackling any problems.
To avoid problems that cause safety hazards and system failure, everyone in a manufacturing plant should know the specifics of the systems they work with. Staff training should include the ins and outs of the system in how it functions and the best practice for plant maintenance to optimise productivity and prevent issues. Starting up and shutting down a heat transfer system, for example, are fundamental skills needed to ensure efficient production.
The ins and outs
The main function of a heat transfer system is to distribute heat around a facility, and to a specific area of the production line. The heating process begins at the main heater, which is comprised of a burner and coil which is cited inside the heater. The burner heats the coil containing the heat transfer fluid. A pump circulates the fluid through the system and controls the pressure. An expansion tank holds any excess oil so that the correct amount of oil is in the system at any one time. This main circuit of the system allows the fluid to travel around the plant efficiently, but more components are needed to ensure the system is safe and stable to use.
One of the most overlooked pieces of equipment in the system is the gasket, which connects flanges that seal the system containing the fluid. At any sign of gasket failure, the heat transfer system must be shut down to prevent hazards and to isolate the issue. Automatic valves are also in the system to regulate temperature and adapt to the product specifications.
When the system is first installed, manufacturers must consider that some components are designed to perform functions specific to a new system. During installation, a strainer is added to catch debris, as anything from metal shavings to bolts can get into the system during construction. General practice for engineers is to remove the strainer after the system has been up and running for around 5 working days. When the strainer is not removed, problems can arise if there is a carbon build up in the system This will cause flow issues.
A clean working environment aids productivity and keeps workers safe. In some cases, there is a lack of general housekeeping of heat transfer systems. Manufacturers can improve plant efficiency by cleaning and fixing leakages immediately as well as using the correct equipment based on temperature and other environmental factors. Leaving oil spills unattended or using plastic equipment can be a health and safety hazard.
As well as protecting workers through cleanliness, purchasing and maintaining safety equipment can improve the efficiency of the heat transfer system. Spray guards are used around flanges and known potential leak points, causing the oil to coalesce back to a liquid and rendering it non-hazardous. This makes the leak safe but visible so manufacturers can solve the issue. Maintaining insulation across the heat transfer system is important as any human contact with exposed equipment may cause serious injury. Using a range of safety protocols can benefit the system operator, meaning they are more equipped to operate the system and manage the risks in the long term.
Though a system is only required to have one major and one minor service in a year, plant managers have a lot to gain from proactive maintenance and checks. Many inspections can be done visually, by a simple walk around check. Maintenance staff should proactively check the system as frequently as possible to look for wear and tear, leaks or other changes.
In order to know what to look for during visual checks, staff should be aware of which parts of the system will need the most maintenance. Workers should monitor the heater daily to ensure that it works efficiently. Monitoring gauges is the principal way to monitor efficiency and discover problems within the system. Another visual cue of a problem in the system would be pipes shaking or slower systems from dust build-up in the vents. Noticing these problems early on can reduce the risk of downtime as parts can be cleaned, fixed or replaced accordingly.
Some visual checks denote external issues, yet visual cues such as inconsistent heating of final products, may be an internal maintenance issue. A lack of representative routine testing and analysis of oil and proactive maintenance can lead to the fluid degrading and carbon forming in the system which may cause the heating fluid, such as Global Heat Transfer’s Thermocare, can reassure manufacturers that it is not the fluid that has caused production issues.
Looking at a heat transfer system alone does not always tell manufacturers how the system in their plant works. Just like an optical illusion, more details are revealed after studying each component. With knowledgeable, trained staff and preventative maintenance, manufacturers can optimise productivity of their heat transfer system, creating satisfaction for workers just like when you spot both hidden images in an illusion.