| 摘要 |
A bitumen filtration system includes bringing in a hot pressurized bitumen from either a feed tank followed by a heater or a HTHP unit. The raw bitumen is pumped at around 400.degree. F and 250 psig through a system of tubular filter cartridges disposed within a chamber. As such bitumen is introduced into the filter, the pressure downstream of the filter is controlled above the initial vaporization point, pressure bubble point, with a back pressure regulator. Such maintenance of the minimum downstream pressure prevents the uncontrolled vaporization of the lighter hydrocarbons, and promotes a uniform deposition of solids over the entire filtering surface. As a filter cake on the filter screens builds up, the upstream pressure increases to maintain a constant flow rate. Downstream of the back pressure regulator the filtered bitumen enters a flash separator at lower pressure where the lightest hydrocarbon and water vapor are separated from heavier components. These lightest materials are passed out of the top of the flash separator to a cooling condenser and an overhead accumulator that collects the light ends. Any condensed water is removed as a separate phase. The cooled and accumulated light ends are both returned to the flash separator in a recycle flow and mixed in with the cooled heavy material liquid product. The result is a final filtered product, with a designed flash point, that can be sent to storage. The light, condensed and cooled overhead that is recycled to the flash separation vessel provides a way to both control the overall operation of the system and a way to control the downstream equipment pressure.
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