Dual purpose bitumen/diluent railroad tank car

Abstract

A dual-purpose railcar is provided, designed for hauling of bitumen or diluent, optimized to provide transport of bitumen to a destination and transport of diluent in the return trip of the car.

1 . A dual purpose railway tank car designed to safely load, carry and unload diluent as well as to cost-effectively load heated bitumen, carry bitumen in an insulated tank, and heat and unload bitumen. 
     
     
         2 . A tank car of  claim 1  that when loaded with bitumen reaches the weight capacity of the rail system, but is less than 90% of the volumetric capacity of the tank car. 
     
     
         3 . The tank car of  claim 1  which has tank shields, end-caps, bottom sump and valve protection, and top side valve locations and is suitable for transport of low vapor pressure diluent. 
     
     
         4 . The tank car of  claim 1  which is insulated and coiled to preserve heat in the bitumen present at loading and so that heat can added to the bitumen prior to unloading. 
     
     
         5 . The tank car of  claim 1  with heat exchange units in or on its tank for heating bitumen with steam provided from sources external to the tank car. 
     
     
         6 . A process of efficient bitumen transport by a dual purpose railway tank car comprising the steps of:
 a. Heating bitumen and flowing the bitumen into the tank car's insulated tank until the car reaches its maximum weight load;   b. Transporting the heated bitumen to a destination by rail;   c. Heating the bitumen in the insulated tank by application of steam supplied at the destination through a heat exchanger in or on the insulated tank containing the bitumen;   d. Flowing the heated bitumen out of the insulated tank until the tank is emptied;   e. Sufficiently cooling the insulated tank by provision of water or a fluid at suitable temperature to the heat exchanger in the insulated tank to avoid flash evaporation of its next load;   f. Loading the tank car to its maximum volumetric capacity with diluent;   g. Transporting the diluent by rail to another destination; and   h. Unloading the diluent from the tank car.   
     
     
         7 . The process of  claim 5 , but with the steps in the order f, g, h, a, b, c, d, e. 
     
     
         8 . The process of  claim 5 , including only steps a through d. 
     
     
         9 . The process of  claim 5  including only steps f through g.