Tank trucks acid unloading

About a year after the system was put in service, the tank was filled via a tank truck, instead of being supplied by the usual pipeline. As the delivery tank truck was unloaded, the acid level rose in the small storage tank. The company representative wanted to top off the tank. 

N Chemical Unloading Facility. The 108-N chemical unloading facility was used for storage and transfer of 93 percent sulfuric acid and 50 percent sodium hydroxide solutions received by railroad tank car or tank truck. The unloading station french drain (120-H-7) was used for neutralization of small releases from the overhead transfer boom. The french drain was used from 1963 until March 1987 (DOE-RL 1990). The french drain was 0.9 m (3 ft) in diameter by 1.2 m (4 ft) deep and consisted of a clay pipe filled with lime (DOE-RL 1990). 

Figure 2-6 Tank truck unloading acid just before failure. Courtesy of Jack M. Jarnagin.

Before the acid truck was unloaded, acid started to overflow and pour through the six-inch (15 cm) line into the scrubber. The alert truck driver quickly responded. He abruptly shut the delivery valve on his truck. Unexpectedly, the partial vacuum created by the siphoning action of the overflowing liquid, exceeded the tank s vacuum rating and the storage tank was totally destroyed (see Figures 2—7, 2—8, and 2—9). [2]... 

N-7 Unloading Station French Drain 93 percent sulfuric acid and 50 percent sodiim hydroxide. French drain for receiving incidental spills during railcar or tank truck unloading. 

A truck driver arrived at the facility to deliver a load of sodium hydrosulfide solution. The delivery took place on the night shift. During prior deliveries on this shift, the shift supervisor had received only pickle acid. (The material commonly known onsite as pickle acid was actually ferrous sulfate.) He assumed that the sodium hydrosulfide was pickle acid and directed the truck driver to unload at the facility s pickle acid tank. Hydrogen sulfide gas was produced when the sodium hydrosulfide solution was unloaded into the ferrous sulfate tank. The truck driver was exposed to the gas and died one Whitehall Leather employee was injured (NTSB, 2000). 

The plant manager is quoted as saying that the chemical company was expecting four acid trucks on that Friday morning. Three of the trucks were carrying sulfuric acid and one was delivering nitric acid. The nitric acid truck was misdirected and partially unloaded in the sulfuric acid tank. 

A tanker truck of hydrochloric acid was inadvertently unloaded into a large storage tank used for sulfuric acid. After about one-half of the 3000-gal load had been discharged, a violent explosion occurred, breaking the inlet and outlet lines and buckling the tank. What might be the cause of the explosion ... 

Chemical hoses must be designed for a specific service. Hoses are required to convey compressed gases, slurries, petroleum products, solvents, bulk chemicals, such as acids and caustics, and a full array of other chemicals that may exhibit flammable, toxic, corrosive, cryogenic, or other harsh properties. Chemical hoses are used for loading and unloading trucks, tank cars, barges, and ships. They may also operate to bypass equipment that has been taken out of service. 

N (1106-N) Chemical unloading facility Unloading area for trucks and tank cars containing sulfuric acid or sodium hydroxide. Three abovegrour d sulfuric acid tanks, one aboveground sodium hydroxide tank and six french drains. 

N Chemical Unloading Facility 93 percent sulfuric acid and 50 percent sodium hydroxide. Unloading area for trucks or railcars. Has three aboveground sulfuric acid tanks and one aboveground sodium hydroxide tank. 

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