90 ton HF tank car two bay unloading plant with a devoted building. Built 1998, used for only several months. The building ( can be transported in parts) is equipped with an air conditioning system that cools the bay and tank car contents to below 67 degrees F (19.4 degrees C) in less than 56 hours when ambient temperature is above 67 degrees F, (19.4 degrees C). A track position censor prevents the car from being unloaded should it be moved. The position censor is interlocked through DCS control, to a temperature-timer subroutine that will not allow opening of automatic block valves until sufficient time has passed with the tank car at the required building temperature. A track derailer equipped with a limit switch ensures that another rail car in the neighboring bay cannot be removed in the vicinity of the HF rail car while it is hooked up inside the building. The rail tank is hooked up for flow to the vaporizer. A Nitrogen pad pressure of 8 PSIFG (0.55 Bar) , reduced from 90 PSIG ( 6.2 bar), is supplied to the car from an outside source. Once the tank is positioned, hoses and all connections are automatically pressure tested with 50 PSIG ( 3.4 bar) nitrogen to ensure no leaks. HF is fed to the vaporizer at a rate of 2-7 GPM ( 7.5 Liter- 26 liter) ( 1000-3500 LB./Hr- [454- 1590 KG/Hr] ), depending on production requirements. The feed flow is accomplished by variable speed control of a double diaphragm metering pump. A totalizer is used to help determine when the tank car is empty. Once determined the car to be empty, the vaporizer is allowed to boil empty. Any liquid HF will be purged back into the car. Then, any residual pressure in the system is bled off to the HF Unloading Fume Scrubber. Automated dumpers are installed in both unloading bays of the bldg. Upon detection of HF by any censor, one of the sets of dampers and an automated valve in the vent header system will open. This will allow 4000 ACFM (6798 CBM/Hr) venting of outside air to be drawn through the bay only to the HF scrubber. A 42 gallon trap tank is located in the inlet of the tank to capture snow melt from the tank cars. The trap is emptied prior to initiating the HF unloading by a wet-dry portable vacuum system. A sump pump pumps any HF spills to the HF Fume Scrubber reservoir for neutralization. The two tank car unloading lines are connected to the HF vaporizer. It is located in a separate, unrefrigerated room, in the building. The room is ventilated through the HF Unloading Fume Scrubber. The vaporizer operates at 45-50 PSIG ( 3 - 3.44 bar) and deliver vaporized HF to the reactor. Automated dampers installed in the vaporizer room of the HF unloading bldg. Provide for the normal make-up air to room when vent system is operating. Upon detection of HF by any sensor, the dampers close, confining vaporized HF to the room until it is exhausted by the ventilation system. The HF Fume Scrubber consists of a 5000 gallon ( 18900 liter) steel storage tank to hold 25% KOH solution, an FRP scrubber with plastic packing, pumps for unloading and circulating KOH solution. Air from the vaporizer room, tank cars unloading lines, local vents, and sump tank vents in the building pass through the scrubber and contact KOH. About 4000 ACFM ( 6798 CBM/Hr) are drown through the scrubber. A pump circulates 25% KOH solution from a 600 gallon ( 2268 liter) reservoir in the bottom of the scrubber back over the packing. The scrubber is designed to remove 99% of the HF when operated at peak anticipated HF loading. The HF Unloading Ventilation Fan provides proper dispersion of any unreacted HF vapor , water vapor and air and is sized to comply with all state regulations. Main equipment components: 2 x HF unloading pumps, mfg. by American Lewa, made of Hastelloy C276/ PTFE rated 7 GPM @ 64 PSI (26.4 liter/ Min @ 4.4bar). Driven by 5 HP 3/60/460V, 1800 RPM motor. 2 x HF Pulsation Preventers, mfg. by Liquid Dynamics type A-28/ Hypalon, 200 degrees F/ 300 PSI (93 degrees C @ 20.6 bar).