EP1293267A2 - Fluidising lances and their arrangement - Google Patents

Abstract

Lances are arranged in groups, each with its own fluid supply. An Independent claim is included for the corresponding method of grouped distribution of pumps and pumping power. Preferred features: There is a common pump (26) and drive, for each group in the tank (1). A suitable pump and drive is provided for each single-lance group. Each lance (10) used in the arrangement, has a pump delivering fluid through its interior, a pump connection and a pump drive. Pump and drive are directly connected to the lance. Direct connection obviates individual couplings. Nozzles and/or screws(s) on the lance, generate flow.

Description

The invention relates to a liquefaction lance for one of essentially identical liquefaction lances constructed arrangement for liquefying large on the bottom Sediments deposited in liquid containers but soluble in the same liquid or thickenings, e.g. when storing crude oil or other liquid Petroleum products are created.

The crude oil extracted from the ground in the extraction of crude oil is initially without any treatment in storage tanks, the crude oil tanks, with large Capacity stored and kept ready for distribution. The service life of the oil in such containers are usually long enough that considerable deposits accumulate Above all, crude oil sludge can collect at the bottom of the same container. The fat this thickened crude oil layer deposited on the ground is often more than one Meter. This thickened mass, which consists of up to 90% of thickened crude oil, can with the introduction of hydrodynamic energy in the form of injected fresh Crude oil liquefied in the same and, for example, immediately the processing process (e.g. refining).

In the patent documents EP-0'160'805 and PCT / CH97 / 00152 methods and the corresponding devices have been described with which such sediments in crude oil tanks or similar storage or transport containers in a recyclable Be brought into shape. For this purpose, according to these publications Injecting crude oil directly above or in the sediment layer special in it Described flow conditions created which a successive, partial dissolution and resuspending of the sediment layer result.

Furthermore, US Pat. No. 4,828,625 describes a method and apparatus for eliminating Sediments in crude oil tanks described, in which crude oil immediately above the Sediment layer and that according to the profile of the sediment over special liquefaction lances are injected. The specified procedure is required due to hydrodynamic losses on the type of feed and distributors and for the operation of the special liquefaction lances an enormously high pumping capacity at 1000 gallons per minute per pump through the supply lines. at This process means 4 times 1000 gallons, which is over 16,000 liters of crude oil pumped into the container per minute. Such pumps with their aggregates are weighing several tons and must be operated by specialists.

The crude oil is injected into the sediment layer in all three Process with either rotating or non-rotating liquefaction lances, which through the openings in the floating lid of the crude oil tanks, in which the stilts normally support to support the lid on the Tank bottom are introduced. These hollow leading the crude oil to be injected Lances are essentially vertical in the manner described above Openings are inserted and their lower end with the nozzles in the for the procedure brought necessary position. Your other end protruding from the top of the container is can be connected to a feed line through which feed line is liquid under pressure is feedable.

The feed system essentially contains feed lines, a central pump and a suction point. A main feed line connects the suction point to one For example, a central pump stationed outside the tank which generates the pressure that is required to inject the crude oil through the lances. At least one additional line is laid on the floating cover and at the end with at least a distribution fitting. At this at least one distribution valve are more Lines coupled. The other ends of these lines are roughly even Spaces positioned on the floating lid and in turn with distribution fittings stocked. Again, several lines are connected to each distribution valve connected and the other ends, if not another distribution to others Lines is necessary to the upper ends of the floating protruding from the Lances coupled.

It is easy to see that a feeding system, which consists of several hierarchies of There are supply lines and a central one located outside the tank Pump is connected, has major disadvantages. Firstly, for big ones Tanks up to 100 meters in diameter and at least many hundreds of meters of pipes be relocated, which means a very large amount of work and material and up the process has significant adverse effects. The hydrodynamic Resistance in this very long feed system causes a large one Amount of energy from the central pump for the transportation of the crude oil through it Lines must be used. A leak somewhere in the pipe system affects negative on the whole device. The closer the leak is to the pump, the more the disruption is perceived to be greater in the overall network.

If the central pump fails, the whole process cannot be completed become. Such a system has insufficient redundancy.

Another serious disadvantage of a device as described above is therein to find that the system is not sufficiently modular, i.e. the whole The device is designed for a certain tank size. A feeding system, which for is designed for a tank of 50 meters in diameter, a device for one Tank with a diameter of 100 meters, which needs a lot more lances, no longer with can supply enough pressure. The pump size must match the respective Tank size can be adjusted. This leads to pumps of different sizes Must be available to sludge tanks of different sizes can, which in turn is associated with high costs.

Another problem is the essentially fixed main lines, which in the event of a level change in the tank, e.g. to lower the floating lid or to lower the lances attached to the floating lid during the Liquefaction process to be performed for various reasons must be dismantled, as this mostly depends on the regulations to which the Operator of such tanks has to be kept is required. The liquefaction process must be interrupted in this case and it is caused by the uncoupling of Lines an enormous amount of time and manpower.

It can be shown that these serious disadvantages with the use of the Invention can be remedied.

According to the invention, autonomous are modular combinable liquefaction lances, which have their own suction point and advantageously their own Pump and feed system have a facility compiled, which e.g. in patent documents EP-160805 and PCT / CH97 / 00152 mentioned methods reliably and without the previously explained Disadvantages of the procedures described in these patents.

The liquefaction lance according to the invention essentially comprises Means for injecting the liquid and at least a suction point. It is possible to use an appropriate number of im essentially identical liquefaction lances according to the invention any desired tank size to be treated without providing a device specifically designed for each type of tank to have to.

The liquefaction process can be carried out with a certain number of liquefaction lances according to the invention are carried out. By the modular system of different autonomous injection points, which the crude oil through the openings in the floating roof, mainly those for the stilts, over the Suction points, you are able to fill any tank size with optimal effort to treat. The feed pump, which advantageously integrated in the condensing lance can be done in the shortest possible way the suction point with the injection point connect. It goes without saying that with such an arrangement a lot fewer lines have to be laid than with the conventional, previous described central feed systems. The only lines, which may be from the floating lid to the area outside of the tank must be guided, are the relatively thin and easy to install Power or hydraulic lines that supply the energy required to operate the pumps positioned on the roof is required if the energy producers (e.g. electrical unit with a possibly required hydraulic pump) not also on the Roof can be operated. It is easy to see that with a Liquefaction plant, which consists of autonomously operating liquefaction lances with suction point there are the disadvantages of a central Feeding system with increasingly heavy and thicker feed lines, which from the roof over the outer wall of the tank to the central one, in the area outside the Storage tank stationed pump must be installed, no longer has. On Another advantage of a modular liquefaction plant is that its system redundancy is guaranteed redundancy of the system. falls a liquefaction lance during the operation of the system, so it can quickly and without interruption the entire process can easily be replaced by a spare lance.

Figur 1

Eine schematische Darstellung des Prinzips des Eindüsens von Flüssigkeit in eine zu bewegende Kreisstromschicht eines zylinderförmigen Rohöltanks mit einer Mittelachse als Strömungszentrum um welches das Fluid, das sich in der bewegten Schicht befindet, kreisförmig dreht.

Figur 2

Eine schematische Darstellung einer autonom arbeitenden Verflüssigungseinheit mit in die Verflüssigungslanzen integrierten Ansaugstellen.

Figur 3

Eine schematische Darstellung einer bevorzugten Ausführungsform einer Lanze mit integriertes Ansaugstelle.

Figur 4

Eine schematische Darstellung einer bevorzugten Ausführungsform einer Verflüssigungslanze mit integrierter Ansaugstelle, bei welcher die eigentliche Förderpumpe durch mindestens eine im Lanzenrohr integrierte und von einer Antriebseinheit angetriebene Schraube oder Turbine ersetzt wird.

Figur 5

Eine schematische Darstellung einer kompletten Verflüssigungsanlage mit einer Mehrzahl von in Figur 3 dargestellten Verflüssigungseinheiten.

The invention is discussed in detail below with the aid of the figures listed below. Show it:

Figure 1

A schematic representation of the principle of the injection of liquid into a circular flow layer to be moved of a cylindrical crude oil tank with a central axis as the flow center around which the fluid located in the moving layer rotates in a circle.

Figure 2

A schematic representation of an autonomously operating liquefaction unit with suction points integrated in the liquefaction lances.

Figure 3

A schematic representation of a preferred embodiment of a lance with an integrated suction point.

Figure 4

A schematic representation of a preferred embodiment of a liquefaction lance with an integrated suction point, in which the actual feed pump is replaced by at least one screw or turbine integrated in the lance tube and driven by a drive unit.

Figure 5

A schematic representation of a complete liquefaction plant with a plurality of liquefaction units shown in FIG. 3.

FIG. 1 shows a schematic representation of the procedure for injecting liquid into a circular flow layer 5 to be moved of a cylindrical crude oil tank 1 with a central axis 34 as a flow center around which the fluid located in the moving layer 6 rotates in a circular manner. Liquefaction lances 10 are immersed in the tank 1 through the surface of the liquid. These liquefaction lances extend into the area of the bottom of the tank 1. The liquefaction lances 10 have rows of nozzles 11 arranged one above the other, which rows of nozzles extend from the end of the liquefaction lances 10 facing the tank bottom to the shear surface 3. The nozzles take on the function of kinetic energy sources.

There are several liquefaction lances 10 evenly on a concentric circle arranged to the tank surface. The liquefaction lances 10 are oriented in such a way that the axis of the nozzles 11 is essentially tangential to the surface of the tank is directed. The openings of the nozzles 11 are in the direction of movement of the circular flow directed. The ends of the liquefaction lances protruding from the tank are included can be connected to a known feed system, which is shown schematically in FIG. 1 by feed lines 20, a distributor 29, a pump 26 and a suction point 21 in the area of the moving Circular current layer 6 is shown. It is thus possible to remove liquid from the circuit current layer to suck it off and pump 26 into the individual liquefaction lances 10 to pumps, where they through the nozzles 11 back into the moving layer 5 can be injected.

The fluid 2, which is pumped through a nozzle, generates a liquid jet which is represented by the directional arrow 36 in the drawing. Are the liquefaction lances 10 in the arrangement and orientation as described above in the fluid 2 introduced, the liquid is injected into the kinetic energy by injecting the liquid Layer 6 introduced that essentially after a constant pump output stationary circuit current develops for some time.

The arrangement and number of liquefaction lances 10 shown in FIG. 1 only shows the principle of creating a circular current layer. Crude oil tanks usually have a diameter between approx. 30 and 100m. It goes without saying that at such dimensions much more liquefaction lances to create a circular flow layer must be used, but also how essential an energy-saving Pumping is as soon as you have to process such enormous amounts of fluid.

FIG. 2 schematically shows an exemplary embodiment of liquefaction lances 10 according to the invention which have integrated suction points 21. The two suction lance elements shown are operated with a common pump 26. The suction point 21 is designed here so that it is designed as a tube in which tube the liquefaction lance 10 can be carried out or is permanently installed.

By choosing the length of the suction pipes 21 and the insertion depth of the suction lance unit is defined from which height of the container 1 the liquid is removed and is supplied via pump 26 to the liquefaction lance 10. The liaison office 17 between the condensing lance and the intake pipe 21 can either be fixed, e.g. sealed by a weld seam or by a suitable non-material fit Seal to be executed. In the second case, the liquefaction lance longitudinally displaceable integrated into the intake pipe relative to the intake pipe become. The end of the intake pipe directed towards the inside of the tank can with one device - e.g. with a sieve - which is the inflowing Fluid 2 filters to a certain extent and prevents solid foreign objects get into the pump 26 via the suction line 22.

Figure 3 shows a schematic representation of a preferred embodiment of a liquefaction lance with an integrated suction point. The liquefaction lance 10 can be constructed modularly. It then essentially consists of the lance end part 15 in which the rotatable or fixed nozzles 11 are integrated, one or more lance extensions 14, if these are required at all, and the lance head 13, in which the suction pipe 21 with the suction openings 12 and the connecting element 18 - shown here as flange 18 - and the upper end of the lance tube 10, which is integrated in the suction tube 21 and is provided at its upper end with a connecting element 19.

The fluid to be sprayed through the nozzles 11 in the lance end part 15 is through the Suction openings 12 sucked, flows through the suction area 16 to the connecting element 18, via a possibly interposed feed line 22 into the Suction opening of the pump 26. The pump 26 pumps the fluid through a possibly intermediate conveyor line 20 - not shown in the figure - in the upper Part of the liquefaction lance, from where it enters the lance end part 15 via the lance tube and is pressed out of the nozzles 11

The suction openings 12 can be designed so that particle sizes could damage the pump 26 or otherwise obstruct the injection cannot get into the suction space 16 at all. This can e.g. through narrow slits, correspondingly small holes or a corresponding screen grille in front of the openings be accomplished.

The pump 26 can be placed directly on the floating lid and through delivery lines 20 and 22 are connected accordingly with the connecting elements 18 and 19. The pump 26 can also be connected directly to a corresponding connecting element 18 or directly to the corresponding connecting element 19 (as shown in FIG. 6b) be connected.

If the liquefaction lance 10 has a modular structure, there are at the corresponding connection points appropriate relatively tight connection means attached, which relatively are easily separable. A liquefaction lance 10 constructed in this way allows the operator the sludge plant an optimal adjustment of the lance length to the respective Requirements. This also avoids that a defective part on the Liquefaction lance leads to failure of the entire liquefaction lance, since the unit with the defect can easily be replaced by a spare part. In the Figure 3 shown liquefaction lance can be assembled from cheap steel. No special precision of the individual components is necessary.

FIG. 4 shows a schematic representation of a preferred embodiment of a liquefaction lance with an integrated suction point. The characteristic feature of this lance design is that an actual expensive and maintenance-intensive feed pump and the supply lines can be dispensed with. A drive unit 27, for example an electric motor, is coupled to the upper end of the liquefaction lance 10 protruding from the stilt opening. The drive shaft 32 of the drive unit is coupled to a transmission shaft 28 which drives at least one liquid screw or turbine 31. The drive shaft or the at least one screw or turbine 31 are rotatably mounted on the bearing block 33.

The fluid is through the top of the pump screw or turbine 31 suction openings 12 located in the lance tube of this screw or turbine 31 sucked in and accelerated downwards and out of the at least one nozzle 11 pressed out lower end of the liquefaction lance 10. It goes without saying that all suction openings in the lance tube are immersed in the fluid must be located.

FIG. 5 shows the schematic representation of a partial liquefaction system or liquefaction device on a tank, which is constructed from a correspondingly required plurality of liquefaction lances with an integrated suction point according to FIGS. 3 and 4 and is driven by an electrical energy source 40 with relatively thin feed lines from outside the tank becomes.

Claims (7)

Liquefaction lance for an arrangement on a storage container (1) for liquids, in particular on a storage container designed for the storage of crude oil with a floating lid, which arrangement is used to liquefy sediments collected on the bottom of the container and which arrangement a plurality of liquefaction lances (10) which penetrate through the surface of the liquid and reach into the region of the bottom of the storage container, at least one nozzle (11) being arranged at the ends of each liquefaction lance directed against this bottom, characterized by the liquid being sprayed out in that the liquefaction lance (10) further above the at least one nozzle (11) has a suction point (21) connected to a suction opening of a pump (26). Liquefaction lance according to claim 1, characterized in that the liquefaction lance with suction point (21) is assigned its own pump (26). Liquefaction lance according to claim 1 or 2, characterized in that the suction point (21) is designed as a suction pipe, the suction pipe surrounding a lance pipe and having at least one suction opening (12). Liquefaction lance according to claim 3, characterized in that the suction tube surrounding the lance tube is displaceable relative to the lance tube. Liquefaction lance according to claim 3, characterized in that it has a lance end part (15) with the nozzles (11), at least one lance extension (14) and a lance head (13) with the suction pipe and the at least one suction opening (12), the lance end part (15), the lance extension (14) and the lance head (13) are separable. Liquefaction lance according to claim 2, characterized in that the pump (26) is designed as a rotating screw or turbine (31) arranged in the lance tube and that the suction point (21) opens into the lance tube at least one above the screw or turbine (31) Has suction opening (12). Liquefaction lance according to claim 6, characterized in that the screw or turbine (31) is driven via a transmission shaft (28), the transmission shaft (28) being coupled to a drive unit (27) and the drive unit (27) at the lance end with the nozzles (11) opposite lance end is arranged.

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