Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
  • B01D21/0006—Settling tanks provided with means for cleaning and maintenance
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
  • B01D21/26—Separation of sediment aided by centrifugal force or centripetal force
  • B01D21/262—Separation of sediment aided by centrifugal force or centripetal force by using a centrifuge
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G11/00—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
  • C10G11/14—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils with preheated moving solid catalysts

Definitions

• the present invention relates to a method and a device for clarifying a viscous petroleum product at room temperature.
• the product concerned in the first place by the invention is the "slurry" product derived from the base of a catalytic cracker or a steam cracker.
• the "slurry” is a petroleum product that leaves the cracker at a temperature of about 35O 0 C which is cooled by circulation in several stages of tubular exchangers and then stored before recovery by incorporation into the heavy fuels. This product is loaded with fine solid particles which come from catalyst pellets.
• the solid products in question are most often alumina and / or vanadium dioxide. These examples are not limiting: these particles may be of the nature of each particular catalyst used. These products have adverse effects in the treatment of "slurry" at the exit of the cracker. Upon cooling, there is a rapid fouling of the tubing associated with significant erosion of their wall. It is then necessary to proceed with their slagging resulting in a significant operating loss by stopping the cracker. It is also necessary to remove the sediment deposited at the bottom of the storage tank or tanks, extremely clogged, so a withdrawal so difficult that sometimes it requires the complete elimination of the tank itself.
• the invention therefore has for its first object a method for treating "slurry" from a cracker, by decanting the solid particles contained in the slurry, comprising introducing said slurry as soon as it leaves the cracker, thus at a high temperature.
• temperature about 350 0 C
• a second object of the invention is an apparatus for implementing the aforesaid method in that the decanter bowl and rotating screws is coupled to a hydraulic drive motor mechanism, for example two hydraulic motors, one coupled to the bowl and the other to the Archimedes screw inside the bowl.
• the mechanism may be a differential mechanism conforming, for example, to those made by Viscotherm, which comprises a motor with a first output and a secondary output in a given transmission ratio.
• the advantage of hydraulic drive is the ability to cool the drive oil by a suitable cooling circuit outside the motor group. between, for example, the return cover and the pump needed to supply the hydraulic power to the power unit.
• the vertical decanter is suspended from the floor of a parallelepipedal support structure which divides this support into two superimposed compartments, each box-shaped, the lower box surrounding the decanter and some of the various accessories necessary for control and control of its operation, the upper compartment / box being equipped with a handling means such as a crane or a pivoting bracket with which it is possible to take care of the decanter for maintenance operations so to depend on the floor t out of the built sound and to present at least an inspection outside the lower box.
• a handling means such as a crane or a pivoting bracket
• the apparatus is thus in the form of a container having the shape of a parallelepiped tower that can be placed on the side of the refining plant producing these slurries.
• the container is sealed and continuously supplied by a source of inert gas, nitrogen for example, at slight overpressure to prohibit any air penetration outside.
• the device will finally include means for extracting solid or pasty waste at the base of the decanter (extraction by a screw conveyor) and a pump intended to ensure the evacuation of the clarified fluid.
• FIG. 1 is a diagrammatic elevational view of a container according to the invention equipped with the centrifugal decanter,
• FIG. 2 is a schematic and partial side view of this container
• FIG. 3 is a schematic top view of this device.
• FIGS. 1 and 5 illustrate a parallelepiped-shaped box-shaped container 1 having lateral outer walls 2, 3, 4 and 5, the partition 5 being movable to cover and reveal an opening 6 for access to the interior volume of the box.
• This structure has a bottom 7, a ceiling 8 with an intermediate floor 9.
• the frame of this box is equipped with a lifting and handling means represented here in the form of a crane 10 but which could very well be a pivoting bracket whose vertical amount would be arranged by example in an interior corner of the box near the opening 6.
• the floor 10 supports a hollow frame 11 in which is housed the rotating bowl 12 of a vertical centrifugal decanter and the central conveyor 13 associated therewith. Bowl and conveyor are suspended at the top of the frame via an upper bearing not shown. In the case of the figure, the bowl is rotated by a pulley 14 driven by a motor 15 and a transmission belt.
• the inner conveyor 13 (an Archimedean screw) is rotated by a hydraulic motor 16 whose outer casing rotates with the bowl.
• This differential bolt / screw drive system is well known; it is placed on the market by a Viscotherm company under the trademark "Rotodif".
• the oil supply of the hydraulic motor is provided by an installation comprising a pump 17, a filter 18 while the return of the fluid passes through a cooler 19 which allows to maintain a suitable temperature at this engine malqré the operation at high decanter temperature.
• the belt drive of the bowl is replaced by another hydraulic motor whose power oil is also vigorously cooled through a heat exchanger.
• the lubricating oil of the supporting bearing of the decanter rotating crew can also be circulated between the bearing and a pump through a cooler.
• a pump through a cooler.
• the pumps, filters and exchangers in the lower compartment of the box located under the floor 9. The upper compartment, above this floor, is then completely cleared and makes the handling of the bowl and conveyor much easier.
• the liquid to be clarified is fed to the base of the centrifugal decanter via a conduit 20 having outside the box a connection flange 21 at the outlet of the cracker (not shown).
• the solid or pasty fraction of the inlet liquid is collected at the base of the decanter and is led outside the housing by a duct 22 provided with a connecting flange 23.
• the clarified liquid is collected at the top of the decanter by a conduit 24, connectable by a connection flange 25 external to the existing plant downstream of the cracker.
• the invention makes it possible to obtain a much better clarification of the slurry, thus a quality of the latter compatible with the next requirements for solid content in these products.
• the internal volume of the box is fed by a source 26 of inert gas such as nitrogen, slightly overpressurized, so as to maintain an inert atmosphere in the box where the risk of explosion and fire are important, given the high temperature at which the products are processed.
• a source 26 of inert gas such as nitrogen
• the installation will include extraction means adapted to the viscosity of the product conveyed (screw conveyor for solids or pastes, pumps for the clarified liquid).
• the treatment device according to the invention is particularly advantageous because it can be set up very quickly, next to the cracker without having to make significant changes to the existing installation.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Centrifugal Separators (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Extraction Or Liquid Replacement (AREA)
• Treatment Of Sludge (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Cites Families (8)

• 2006
  • 2006-02-10 FR FR0601195A patent/FR2897278B1/fr not_active Expired - Fee Related
• 2007
  • 2007-02-09 US US12/278,936 patent/US20090039036A1/en not_active Abandoned
  • 2007-02-09 EP EP07730948A patent/EP1981607A2/de not_active Withdrawn
  • 2007-02-09 WO PCT/FR2007/000234 patent/WO2007093691A2/fr not_active Ceased

Non-Patent Citations (1)

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