6.It is strictly forbidden for the floating plate to drop to the bottom during the operation of the internal floating roof storage tank.
6.It is strictly forbidden for the floating
plate to drop to the bottom during the operation of the internal floating roof
This article mainly stipulates the
requirements for the liquid level of internal floating roof storage tanks. The
bottom of the floating plate means that the floating plate falls on the support
leg due to the low liquid level of the storage tank. During normal operation,
when the floating plate falls to the bottom, a gas phase space will be formed
between the floating plate and the oil surface. When the material flow rate is
too fast, static electricity at the pipe orifice of the material pipeline is
likely to accumulate, which can easily cause fire and explosion accidents.
A typical accident case:
On August 29,
2011, a diesel tank of PetroChina Dalian Petrochemical exploded and caught
fire. The main cause of the accident was the low level of oil from the storage
tank. A gas phase space was formed between the floating plate and the diesel
liquid level, causing air At the same time, the operation of the upstream
device fluctuates, and the content of light components in the diesel oil
entering the accident storage tank increases, forming an explosive mixture
below the floating plate; In addition, the flow rate of the oil is too fast, a large
amount of static electricity is generated and cannot be discharged in time,
resulting in discharge, causing an explosion and fire .