Thermal oil is an ideal heat carrier, it can reach 320℃ at atmospheric pressure. It is also widely used in chemical industrial because of the good heat transfer efficiency. Thermal oil normally composed of alkane, cyclane, arene and other organic compounds. Theoretically these organic compounds do not corrode steel equipment. In fact, there are potential risks which is caused by aged thermal oil.
Thermal oil will have an oxidation reaction with oxygen under high temperature condition. If there is no nitrogen protect the thermal oil, they will even react with oxygen in the air during the process. In this way, some acidic substance is produced and corrode the equipment.What is more, the acidic substance promote polymerization of the thermal oil. It will increase the viscosity of thermal oil, cause coking, reduce the heat transfer efficiency. In the end the oxidation reaction cause a chain reaction and lead to perforation accident and explosions.
Operator should firstly avoid the oxidation to protect the whole system and avoid a series problem.
- To protect the thermal oil from contact with oxygen, the best way is to fill the circulation system with nitrogen or other inert gas.
- Dewater the thermal oil strictly. Water, low boiling point substance and other impurity must be avoided to come into the thermal oil heating system
- Make sure the thermal oil is flowing in the system at a proper speed.
- Operator should analysis the thermal oil from time to time to check the oil quality.