01 / The challenge
Inconsistent heat was slowing production.
The asphalt plant's thermal fluid heating system could not consistently maintain thermal balance. Production suffered, while extra manual work and component wear increased the burden on maintenance. Crews sometimes had to heat pumps and injection pipes manually to restart the process.
The plant needed more consistent heat delivery from the oil already circulating through the system. The case appears in a Fluitec and ExxonMobil paper on heat-transfer fluid degradation, which explains how carbon-rich deposits can interfere with heat transfer. Treatment therefore had to be assessed through both plant performance and the condition of the oil.
02 / The approach
Treat the existing fluid and follow the system response.
Treat the oil already in service
The plant added Mobil™ Solvancer® to its existing heat-transfer fluid at a reported concentration of 3.3%. This was the treatment used in the documented case; selection and dosing for another system depend on its fluid and operating conditions.
Check thermal balance and startup behaviour
The paper reports restored thermal balance after a few weeks, with faster startups. The plant had previously needed crews to manually heat pumps and injection pipes when restarting the system.
Follow fuel use and oil condition
After more than six months, the plant reported lower fuel consumption and improved operating reliability. Oil testing showed improvements in viscosity and micro carbon residue, with no change in the fluid's flash point.
03 / The results
Lower fuel use and more reliable heat delivery.
The paper reports the following observations after more than six months. Thermal balance had improved after a few weeks; the later account also describes longer production runs, faster startups and reduced pump wear.
| Measure | Reported outcome |
|---|---|
| Fuel consumption | 20% decrease reported |
| Thermal balance | Restored after a few weeks |
| Hot-oil breakdowns | Zero reported during the follow-up |
| Oil condition | Improved viscosity and micro carbon residue; unchanged flash point |
| Oil replacement | Full system oil change avoided |
The 20% figure is the plant's reported reduction, rather than a forecast for another site. The paper does not publish raw fuel-use records or a production-adjusted comparison, and notes that operating and weather conditions can affect results.
04 / Applying the findings
Review the oil alongside the heat-transfer problem.
Higher fuel use, slow startups and uneven heat delivery need a system-level investigation. This case shows why oil condition belongs in that review: the plant reported improvements in the fluid alongside changes in operating performance. Fuel consumption should be compared with production output and operating conditions so the effect of treatment can be assessed fairly.
Bring the fluid name, operating temperatures, system volume, recent analysis and the history of the problem to NATCOM. Our oil analysis service can help define the testing needed for a treatment decision. The partner paper considers viscosity, deposits and flash point together; a deposit-removal result alone does not establish that an oil remains suitable for service.