| 摘要 |
A system for drying and ventilating jet fuel tanks for reducing the fuel fume level from residual fuel in an emptied fuel tank operates in four modes. In a recirculation mode, a blower recirculates air through the tank in a closed loop. The blower suctions air from the tank and forces it through a vapor recovery unit having a cooling section with a refrigeration coil causing condensation of fuel vapor and a reheater section which reheats the air entering the tank to enhance evaporation of residual fuel. A heat recovery system circulates glycol/water mixture through a first heat recovery coil in the cooling section for absorbing heat from the air and a second heat recovery coil in the reheater section for returning the heat to the air. After fuel vapor has dried from the walls of the tanks, the system operates in a vacuum mode in which a vacuum hose, obtaining negative pressure through a pipe from the suction side of the blower, is used to remove residual puddles of fuel from the tank. After a hand-held vapor sensor determines that the fuel vapor has dropped to a safe level, a ventilation mode is used, circulating fresh air through the tank to the atmosphere, bypassing the vapor recovery unit. A temperature sensor monitors air returning to the tank. When the temperature approaches the flashpoint of the jet fuel vapor, an alarm is actuated. In a test mode, pressure is applied to the system to test it for leaks.
|
