Description

High quality mineral oil used as a heat transfer fluid, where the operating temperature reaches up to +320°C. It can also be used for cooling metals and painting steel.

Applications

• Closed heat transmission systems up to +320°C.
• Open heat transmission systems up to +220°C.

Properties – Benefits

• Large temperature range from -18°C to +320°C.
• Extremely high heat transfer coefficient.
• Extended oil life thanks to its high thermal stability and resistance to the breakdown of its molecules.
• Increased oxidation resistance.
• It is non-toxic and non-corrosive and has a low vapor pressure.

Operation instructions

An important factor for the lifespan of the mineral oil is the heater. In order to avoid problems and extend the lifespan, the circulator must be able to create a turbulent flow inside the heater with surface velocities of 2.0 – 3.5 m/sec depending on the surface geometry. Thus, the heat transfer will occur uniformly throughout the mass of the oil, without local overheating in the boundary layer of the oil (that is, that which comes into contact with the heated surfaces), which would result in the breakdown of its molecules and its oxidation. The permissible temperature limit for this layer is +340°C. For the same reason, the heating flames must not hit the oil pipes directly.

It is necessary to have an expansion tank, which will allow changes in the volume of the mineral oil during heating or cooling. The container must be large enough to accommodate the increase in volume of the mineral oil due to its expansion. For this calculation, the approximate tables of density change with temperature, which we list, are useful. The piping system must be provided with sufficient vents to remove steam and entrapped air, which at high operating temperatures has a tendency to oxidize the oil.

Finally, the constant flow through the heater regardless of the conditions in the treatment vessel can be realized with a by-pass piping along this vessel, which will carry a constant pressure valve, capable of accepting the entire supply of oil.

Lifespan –  Maintenance

TRANSFIRE ‘s lifespan, in any system it is being used, depends on the design and use of the system. So, if it is well designed and does not receive uneven heat loads during use, the mineral oil can last for many years. It is very important to regularly check the condition of the mineral oil, since the rate of change of the physical characteristics is more important than the actual values. We must take a sample from each system newly filled with mineral oil about a week after start-up to create a record. Later on, we have to take samples every 6 months and compare the results with those of the previous samples. The properties of mineral oil that must be checked are viscosity, acidity, flash point and its content of insoluble components.