At approximately 10:45 p.m. on February 8, 2017, a fire and explosion occurred involving a high-boiling-point solvent tank at Hengxing Chemical Co., Ltd. in Tongling, Anhui Province, China. 

According to information cited from the Tongling Work Safety Administration in the original report, the company had been using steam to heat the solvent oil tank since February 5.

Rising Temperature and Pressure Preceded the Explosion

According to the incident report, a valve connected to the steam pipeline may not have been completely closed.

This may have caused the temperature of the solvent oil inside the tank to rise, resulting in vaporization and increasing pressure within the tank. 

As the pressure increased, gaseous and liquid high-boiling-point solvent escaped through the atmospheric vent pipe.

The released material subsequently ignited after coming into contact with a high-temperature source, resulting in the explosion. 

Temperature Monitoring in Petrochemical Environments

Temperature is an important operating and safety parameter in many petrochemical processes, particularly where combustible materials, storage tanks, pipelines, heating systems, and other thermal processes are involved.

Abnormal temperature changes can provide valuable information about changing operating conditions and may help plant personnel identify situations requiring further investigation.

For large industrial assets and extended monitoring areas, distributed fiber optic temperature sensing can provide continuous temperature measurements along the sensing fiber rather than relying solely on individual point sensors.

Fiber Optic Sensing for Industrial Fire Monitoring

Distributed Temperature Sensing (DTS) is used in a range of industrial temperature and fire-monitoring applications.

In suitable applications, fiber optic sensing offers advantages including continuous temperature monitoring over extended distances and the absence of electrically powered sensing elements along the optical fiber itself.

DEAN Technology's current petrochemical solutions include Distributed Temperature Sensing (DTS) fire detection for oil storage tanks as part of its fiber optic sensing applications. 

Monitoring technology, however, should form only one part of a broader industrial safety strategy incorporating process control, equipment inspection, maintenance, fire protection, operating procedures, and emergency response.