EP0160805B1 - Method and apparatus for the recovery of crude oil or refining products from their sludge - Google Patents

Description

The invention relates to a method according to the features defined in the preamble of claim 1 and an apparatus for performing this method.

It is customary in crude oil production to store the crude oil extracted from the ground in a storage container and to keep it ready for distribution after any degassing. The service life, for example in containers in the 10̸0̸'0̸0̸0̸ m3 category, is usually long enough that considerable sedimentation can form, especially in extreme climatic conditions. Since crude oil as a natural product can have a very different composition depending on the provenance, the frequency of sediment formation, the formation and the type of sediment are very different. In a conventional circular cylindrical crude oil tank with a diameter of approx. 10̸0̸ meters, sedimentation layers mean a few 18 centimeters Already a noticeable loss of the crude oil bound in it and as an absolute amount of material a real problem for disposal. Sedimentation layers with a thickness of 10̸0̸ to 150̸ cm are not uncommon, especially if you have to add more crude oil after various withdrawals, without emptying the container or worrying about possible sedimentation.

The type of sedimentation depends on the type of crude oil, it can be excreted asphalt or excreted paraffins, waxes, or any higher molecular weight hydrocarbons; the sedimentation can also consist only of a thickened fraction from the crude oil. The latter is formed, for example, under the influence of heat, which can remain consistently high over long periods in hot desert areas. The result is a kind of oil sludge that can condense into sediments. This oil sludge can be considered in its yogurt-like consistency as a crude oil fraction and it also consists largely of crude oil, or of thickened portions that are redissolvable in crude oil.

However, this oil sludge is primarily an undesirable material that reduces the container capacity, clogs the pumping, etc. In short, a material that should be removed from the tank as a nuisance. This is done, for example, in the form of cleaning the empty pumped containers. This problem is dealt with, for example, in US Pat. No. 3,436,263, and what is obvious is used, a cleaning material with which the oil residues are loosened or removed. The final disposal of the sedient then usually takes place via a landfill of the oil sludge in a "sacrificed" container. A reprocessing of the oil sludge is still not systematically considered or even carried out today.

FR-A 2'211'546, for example, also deals with the dissolution of such sediments, and chemical foreign substances are also used in accordance with the regulation given therein. This is of course a problem for the manufacturing companies entrusted with the refinery.

US Pat. No. 4,426,233 describes a further cleaning method for removing oil sludge from floating roof oil tanks. After the stored oil has been drained, the exposed sediment is loosely sprayed using a liquid pressed through nozzles and washed together with the spray liquid into a storage tank under negative pressure. Due to the direct spraying of the sediment, solids such as stones, pieces of metal and considerable amounts of rust in pieces and flakes also get into the debris. In addition, the spray pressure must always be maintained over a relatively large distance due to the dimensions of a very large oil tank, which requires a very high pumping capacity. If the ejection agent is water, for example, then another container has of course been filled with residues and spray liquor and in turn is waiting for disposal. Basically, the problem is only shifted, but not solved.

When cleaning tanks, the cleaning agent used must be as cheap as possible and therefore water is usually used. Criteria other than this are seldom considered. Only where the use of water is prohibitive are other rinsing liquids used. Usually a solubilizer is added to the water in the case of crude oil sludge. It should also not be neglected that the flushing medium is added to the total amount disposed of, so there are large amounts of oil-water-dirt sludge when using water. This procedure is known and is actually a general cleaning principle.

Oil refineries are usually set up for the specific processing of crude oil and the systems provided for this work with parameters that are set to the provenance of the product to be processed. Foreign substances, i.e. non-crude oil artifacts that have been introduced, may interfere with the refining process, so that the operators of the refineries almost always reject the use of such agents. So it mostly remains with complex cleaning processes and environmentally harmful disposal and not least with a constant reduction in the total storage capacity due to oil-filled containers or a new construction of containers.

It is therefore an object of the invention to provide a method by means of which the crude oil bound in the sediments is recovered, with which disposal which is harmful to the environment is dispensed with and that it is a method which does not require any foreign substances contaminating the crude oil. Furthermore, it is an object of the invention to provide an apparatus for performing this method.

This object is achieved by the invention defined in the characterizing part of claims 1 and 12.

The surprising finding stems from the observation that the sedimented residues, for example in a crude oil storage container, consist essentially of crude oil and that the same material from which the sediment was formed can be used for re-liquefaction for several reasons to dissolve these residues. In the crude oil from which the residues have separated and which is already above the sediment layer, the same is introduced into the sediment as a liquefier under pressure. The hydrodynamic energy of the injected crude oil destroys the gel-like structure of the sediment, for example, and the affine character of the material allows the crude oil released to be dissolved together with soluble particles. The process according to the invention allows an economic gain that significantly exceeds the process costs. Nowhere in the industry has this type of approach been known.

An additional significant advantage of the new process is that increased security is created for the workers involved, since no direct human intervention is required during the liquefaction and thus for the discharge of the sediments and therefore there is no contact with the harmful and flammable substances. Whereas previously the sediments had to be dismantled directly by human workers with the help of hand tools, the new process also ensures maximum safety against fire and explosion.

Another advantage is that the process can run at any temperature. Without heating or cooling measures, it can therefore be used in petroleum-producing areas with a wide variety of climatic conditions and also in areas with frequently fluctuating temperatures.

The new process now enables the containers to be freed from volume-consuming sediments and thus to maintain their original storage capacity, even if they are not empty. With fully or partially filled containers, it can run simultaneously during filling or removal processes without significantly impairing the handling operation.

The method mentioned can be used in any crude oil container in the broadest sense for the prophylactic prevention of thickening or sedimentation or for the removal of existing sedimentation, for example in crude oil tankers, but also in pipelines in which sedimentation has occurred due to a lack of flow velocity.

The device for carrying out the method according to the invention has an arrangement of at least two liquefaction lances which are functionally connected via a controller (µP, MUX, L / R) and have vortex-generating nozzles (A₂₂, A₃₃) which are arranged and designed to be operable, and so are designed to be operable such that the hydrokinetic energy injected directly into a liquid medium through the nozzles can be successively transferred to a vortex system to form a targeted flow (F). The lances are introduced through existing openings in the transport or storage container, a plurality of lances preferably being used in interactive operation. The liquefaction lances are controlled manually or remotely, if necessary with the help of computers. The device provides for recirculation of the crude oil in order to optimally use the liquefier.

Figur 1 :

Einen Lagerbehälter mit einem Durchmesser von ca. 10̸0̸ m, horizontal geschnitten, mit Blick auf die Topographie der darin abgelagerten Sedimente, in schematischer Darstellung.

Figur 1A:

Ein anderes Sedimentrelief in einem Lagerbehälter mit einem Durchmesser von ca. 85 m.

Figur 2 :

Eine Düsenanordnung an einem Lagerbehälter, zur Zufuhr von hydrodynamischer Energie und Verflüssigungsmittel in einen Bereich der Sedimententopographie.

Figur 3 :

Die hydrodynamische Wirkung von zwei Düsen, die in verschiedenem Drehsinn rotieren.

Figur 4 :

Die ungefähre räumliche Ausbreitung eines ungestörten Flüssigkeitsstrahls aus einem rotierenden Düsenkopf der Vorrichtung gemäss Erfindung.

Figur 5 :

Ein Schaltschema einer Mehrzahl von einzelnen Verflüssigungslanzen mit Düsen, die zu einem Wirbelsystem zusammenwirkende Einzelwirbel erzeugen.

Figur 6 :

Eine erste Ausführungsform der Vorrichtung zur Durchführung des erfindungsgemässen Verfahrens, in schematischer Darstellung.

Figur 7 :

Eine zweite Ausführungsform der Vorrichtung zur Durchführung des erfindungsgemässen Verfahrens, in schematischer Darstellung.

Figur 8 :

Eine schematisch dargestellte dritte Ausführungsform der Vorrichtung zur durchführung des erfindungsgemässen Verfahrens, in den Fällen, wo die Lage, die Menge, das Niveau und/oder die Beschaffenheit des Sediments, diese Ausführungsform erforderlich macht.

Figur 9 :

Eine erste Ausführungsform einer Rotationsdüse für die Vorrichtung zur Durchführung des erfindungsgemässen Verfahrens.

Figur 10̸:

Eine zweite Ausführungsform einer Rotationsdüse für die Vorrichtung zur Durchführung dem erfindungsgemässen Verfahrens.

Figur 11:

Eine dritte Ausführungsform einer Rotationsdüse für die Durchführung des erfindungsgemässen Verfahrens.

Figur 12:

Eine Ausführungsform einer Verflüssigungslanze mit einem Gelenk und einer Mehrzahl von Rotationsdüsen und und Rückstossdüsen für den rotatorischen Antrieb der Verflüssigungslanze.

Figur 13:

Eine andere Ausführungsform einer Verflüssigungslanze mit drehbarem Arm und darauf angeordneten Rotations- und Rückstossdüsen.

Details of the method according to the invention and the device for carrying it out are described in detail below using examples with reference to the drawings. It shows:

Figure 1:

A storage container with a diameter of approx. 10̸0̸ m, cut horizontally, with a view of the topography of the sediments deposited in it, in a schematic representation.

Figure 1A:

Another sediment relief in a storage container with a diameter of approx. 85 m.

Figure 2:

A nozzle arrangement on a storage container for the supply of hydrodynamic energy and liquefier in an area of the sediment topography.

Figure 3:

The hydrodynamic effect of two nozzles rotating in different directions.

Figure 4:

The approximate spatial spread of an undisturbed liquid jet from a rotating nozzle head of the device according to the invention.

Figure 5:

A circuit diagram of a plurality of individual liquefaction lances with nozzles that produce individual vortices that interact to form a vortex system.

Figure 6:

A first embodiment of the device for performing the method according to the invention, in a schematic representation.

Figure 7:

A second embodiment of the device for performing the method according to the invention, in a schematic representation.

Figure 8:

A schematically illustrated third embodiment of the device for performing the method according to the invention, in cases where the location, the amount, the level and / or the nature of the sediment make this embodiment necessary.

Figure 9:

A first embodiment of a rotary nozzle for the device for carrying out the method according to the invention.

Figure 10̸:

A second embodiment of a rotary nozzle for the device for carrying out the method according to the invention.

Figure 11:

A third embodiment of a rotary nozzle for carrying out the method according to the invention.

Figure 12:

An embodiment of a liquefaction lance with a joint and a plurality of rotary nozzles and and recoil nozzles for the rotary drive of the liquefaction lance.

Figure 13:

Another embodiment of a liquefaction lance with a rotatable arm and rotating and recoil nozzles arranged thereon.

Figures 1 and 1A show examples of sediment reliefs as they extend over the bottom of a storage container of approx. 10̸0̸m and another storage container of approx. 85m diameter. In this example, measurements were carried out using lancing probes at various measuring points labeled with the sediment height in cm. It should be mentioned that other known measuring devices can also be used which meet the high requirements for fire and explosion protection. Mixing propellers are located on the inner periphery of the tank. They have the task of keeping the tank contents slightly in motion and possibly preventing sedimentation. These mixing propellers also influence the sediment topography, depending on its position in the container. The two examples are intended to show how sedimentation develops locally if the mixing propellers are evenly distributed around the circumference of the container or if they are only on one side. As a rule, such measures only partially serve their purpose; the mixing propellers presumably only provide for the formation of the topography of the sediment rising towards the container center or against one side of the container wall, such as the actually measured formation of sediment accumulations shown here. As mentioned, it is an indirect object of the invention to bring such a sediment accumulation into the liquid phase and, if necessary, to separate this phase from foreign solid particles in order to recover the crude oil bound by stagnation and precipitation.

As can be deduced from Figures 1 and 1A, the containers in which the sediments with the crude oil which one seeks to recover are located, are generally vertically arranged cylindrical tanks with approximately flat bottoms. As shown in FIG. 6, they are often covered by so-called floating roofs, which have stilts on their underside, usually insertable and extractable through appropriate openings in the roof, by means of which the very heavy cover is prevented from sitting on the bottom and thus on the sediments when the tank is empty. When the tank is completely or partially filled, the lid 'floats' on the stored crude oil. The new process can also be used to recover crude oil from sediments that have settled in tanks with firm roofs. The measured topographies of the sediments deposited on the bottom of the container and shown in FIGS. 1 and 1A represent examples that are still to be discussed.

• 1 -- Vorbereitungen zur Verhütung eines möglichen Brandes oder einer Explosion (wenn überhaupt erforderlich)
• 2 -- Das Anordnen und Montieren der Vorrichtung zum Eindüsen und Absaugen vorzugsweise unter Rezirkulation;
• 3 -- Die Durchführung der Verflüssigung des Sediments oder des Rohoelschlammes.

The implementation of the entire procedure with the method according to the invention is mainly divided into the following work steps:

• 1 - Preparations to prevent a possible fire or explosion (if any)
• 2 - The arrangement and assembly of the device for injection and suction, preferably with recirculation;
• 3 - Carrying out the liquefaction of sediment or crude oil sludge.

1. EVENTAL MEASURES FOR EXPLOSION PREVENTION.

It is, of course, obvious that safety measures should be taken when handling such highly flammable substances, even if they are very complex, have top priority. In the case of tank systems of the order of magnitude described, extreme safety measures against the risk of fire are even necessary. If this is necessary or desired for any reason, the crude oil container is emptied in a first step, ie the excess liquid portion is pumped out of the container. The floating cover lowers until it stands on the bottom of the container with its stilts. Along the circumference of the cover, the gap between the cover and the container wall and all openings in the cover itself, except those with which it is used, are sealed. This precaution prevents the uncontrolled escape of gases and crude oil mists etc. during the injection into the sediment layer on the one hand, and prevents the return of any flushed or displaced oxygen on the other hand. Sealing is done with known means, for example with plastic films or with the help of inflatable sleeves, which nestle tightly into the openings. The procedure is also suitable for cutting a foam mass to size so that the openings are appropriately clogged.

Then a targeted displacement of combustible gases and any oxygen can take place within the container part sealed by the seal, into which an inert gas such as nitrogen, carbon dioxide etc. is introduced through openings provided for this purpose; After flushing, the container is kept under a slight inert gas pressure to prevent new oxygen from penetrating during the injection and suction. It is important to ensure that the combustible gases or vapors that are constantly forming cannot mix to form explosive mixtures with any air oxygen that may still penetrate.

Therefore, the oxygen concentration is constantly monitored analytically during the implementation of the process to ensure that no explosive mixtures can form even after the safety precautions have been carried out and while working. If the oxygen content approaches a prescribed safety limit, new inert gas is supplied immediately.

In this way, the container is protected against ignition by sparks, mainly those from static discharges.

2. ARRANGEMENT OF THE INJECTION AND SUCTION DEVICE.

In parallel to the sealing measures and at the same time for safety reasons, a number of nozzles for injecting crude oil or fractions therefrom are installed in the openings of a floating cover, for example, in the sealed container part. For this purpose, existing openings in which the nozzles are fitted are used in the cover and possibly in the container wall, particularly in the case of "firm roofs". In the case of motorized drives, for example for controlling the nozzles, compressed air or pressure oil-operated units are used for reasons of maximum, even extreme fire protection. Preferably, the pressurized crude oil or fractions therefrom, which are used to dissolve the sediment, are used to drive the rotary nozzles for the specified device. Nozzles of this type for left and / or right hand movements will be described later.

The slurried sediment can then be suctioned off. The existing drainage pipes of the tank are used for this and / or similar to the assembly of the nozzles, through drainage pipes connected to the openings provided for this purpose.

As already mentioned, higher efficiency is achieved with the use of rotating nozzles and with surface-covering, rotating nozzle arms with which the liquid jet can be directed either horizontally, obliquely, vertically or in a combination thereof. In this way, the effect of the hydrodynamic energy can also be brought behind flow obstacles such as the stilts of the cover. With rotary nozzles, the hydrodynamic energy can be added and directed in a targeted manner via vortex formation and the resulting higher flows. Individual rotating nozzles can be regarded as flow generators; the rotating nozzle, which is constantly pressurized with oil, is the energy source of the vortex, which, in a kind of long-distance effect, transmits the aforementioned flow, hydrodynamic energy and, at the same time, liquefier into the sediment topography. Such flow generators can, as will be shown below, be combined to form higher flow systems.

An optimized operating method is based on this idea of a controlled system of fluid vortices, as an example of two vortices running in opposite directions is shown in FIG. 3. A22 denotes the center of a clockwise rotating vortex and A33 denotes a center for a counterclockwise rotating vortex. The vortex is triggered by a rotary nozzle and is energetically maintained by it. In this vortex system, a flow F is formed from the top right to the bottom left, between the vortex the streamlines condense, where the flow velocity is highest. Going back to FIG. 2 shows this a freely chosen swirl system, for example, created on a network with the coordinates A11 to A44. Some of the intersection points are equipped with counter-rotating rotating nozzles and some with counter-rotating rotating nozzles. The nozzles A12, A13, A21, A31 and so on, that is to say the peripheral nozzles, rotate counterclockwise and primarily generate the current F + which also flows counterclockwise; the nozzles A22, A23, A32, A33 primarily generate the clockwise rotating current F-, which is supported by the peripheral nozzles. In the center M, the flow is rather unclear, unordered conditions which can be handled by subsequently operating the nozzles according to FIG. 3. Both figures only show the operating principle and, in order not to overload the figures, are only partially implemented.

Usually for structural reasons the stilts on the container roof are also systematically arranged and, as I said, they are usually slidably guided through the container roof. If the roof is in the "floating" state, any number of stilts can be pulled out and the liquefaction lances with the rotating nozzles can be inserted through the stilts opening. In this case, inerting is not necessary because there is no gaseous oxygen to generate an explosive gas mixture. It is always possible to produce a simple vortex system according to FIG. 3, but mostly it is possible to produce a higher-order vortex system, as is partially shown in FIG. 2, with strong flows F- containing a lot of hydrodynamic energy. If the corresponding layer thicknesses of the sediment are known after measuring the sediment topography, the crude oil (or fractions thereof) containing the hydrodynamic energy can be used in a targeted manner to liquefy the sediment by means of a controlled vortex system. With sediments According to FIG. 1.1A, for example, using only two nozzles (according to FIG. 3), the thicker layers, some of which are almost two meters thick, can be broken down to such an extent that they assume an average thickness. Currents according to FIG. 2 can then be generated.

It is not necessary to attach or insert the nozzles at the selected coordinate points before each operation. Rather, it makes sense to optimally place a plurality of rotary nozzles according to a "flow effect plan" and to control them in terms of height and direction of rotation with respect to one another. The nozzles that are in operation, that is to say rotating, are preferably lowered through a crude oil layer above the sediment to the sediment, and the flow formed is then controlled in height or vertically. During operation, pairs of nozzles can be changed in the direction of rotation for a flow direction reversal, such a nozzle arrangement is described in FIGS. 10̸ and 11. With the underlying flow action plan, the device is advantageously controlled via a computer. Parameters by which the device is switched are, for example, operating times, altitude, direction of rotation and interdependent pairings of rotating nozzles.

FIG. 4 still shows schematically an embodiment of one of the rotary nozzles to be used with its approximate spatial range of action. More precise information can be found in FIGS. 9, 10̸ and 11. For safety reasons, the rotating nozzle heads are oil-driven; if necessary, pressurized gas operation can also be provided. However, it is preferable to use a drive via or with the liquefaction agent itself; the crude oil to be injected in this case is brought to pressure and enforced using conventional feed pumps. The example shown is one of a variety of options; the nozzle head 12 sprays crude oil through openings B in three directions. The idealized lateral surfaces, which are described by an undisturbed rotating liquid jet, are drawn around the nozzle head, with a diameter D of up to 10̸m possible depending on the design. In operation, however, only the macroscopic effects or effects of the nozzle body immersed in crude oil can be described and this is a gradually developing swirling vortex, as described above. In the case shown, crude oil is rotated axially downward in an invariant manner. At best, a nozzle cone is formed here, which, after impacting the bottom of the container, undergoes a presumably trumpet-shaped expansion. The other two cones, in which liquid is directed diagonally upwards and diagonally downwards, are not nozzle cones, but conical lateral surfaces, which are described by the rotating liquid jet. The nozzle head 10̸ consists, for example, of an inner body containing liquid chambers and channels, which is firmly connected to the crude oil supply 15, and a rotatable capsule 14 (FIG. 4) with a plurality of nozzle openings. The capsule can be driven, for example, by a compressed air turbine, the associated turbine either being designed for left-hand or right-hand rotation or a nozzle head being equipped with left / right-hand rotation turbine (s). The compressed air valves are preferably computer controlled in a larger system. Such CNC controls, including software, are now fully developed for general applications; such a control is indicated in FIG. 5. If pressure oil is used to rotate the nozzle, which can be the pressurized oil to be injected, it is advisable to use a nozzle head as described in FIGS. 9, 10̸ and 11 in the later part of this patent application.

3. LIQUIDATION OF THE SEDIMENT.

• das Risiko des Einschleppens von Verunreinigungen in das Rohoel wird erheblich verringert,
• es besteht zwischen Uebertragungs- oder Verflüssigungsmittel eine vollständige Affinität,
• aufgrund dieser Affinität wird die Festphase in höchstem Grad wieder in die herangeführte Flüssigkeit aufgenommen.

According to the invention, the liquefaction takes place with the aid of the hydrodynamic energy of a crude oil jet injected into the solid phase with pressure. The sediments often show a thixotropic behavior, so that when they get into a current, they quickly liquefy. There are several advantages to using crude oil, if possible of the same provenance, for the transfer of energy to the solid phase:

• the risk of contaminants being carried into the crude oil is considerably reduced,
• there is complete affinity between the transfer or liquefier,
• Due to this affinity, the solid phase is absorbed again to the highest degree in the liquid introduced.

However, recirculation is necessary in order to get by with smaller amounts of fresh crude oil or fractions to be used. The liquid phase pumped out by means of drainage is constantly checked for its viscosity and fed back into the nozzle lines for the liquefaction process until the viscosity reaches a predetermined threshold. In this case, a filter can be switched on in the recirculation in order to separate out "crude oil-foreign" impurities, for example sand and rust components of the container. The re-liquefied residue can then be passed, together with the crude oil used for liquefaction, or fractions thereof, into a storage container provided for this purpose or directly into the refinery, in order to return it to normal use as crude oil.

The device for carrying out the method according to the invention is discussed in more detail below.

This device consists essentially of pressure medium-operated liquefaction lances, i.e. rigid oil feed pipes with attached nozzles or hollow joints, multi-section liquefaction lances, as well as pumps for the supply of the fresh liquefaction agent, such as crude oil or fractions thereof, intended for liquefaction. The pumps also build up the required operating pressure and pump out the liquefied crude oil sediments in the drainage, together with the supplied crude oil and ultimately also to maintain the recirculation of the liquefied phase back to the nozzles and, if necessary, to discharge the liquefied phase into another Container in which it is used as normal crude oil, or directly in the refinery for further processing.

Furthermore, filters are advantageously used in the recirculation lines in order to be able to remove solid impurities which are foreign to crude oil. The pipes required are provided with branches and taps to divert the liquid flow as required. It is advantageous to use flow meters with which the yields can be controlled. Measuring devices for viscosity measurements, for oxygen measurements and other means used for analysis are used in accordance with the known procedure.

Figure 6 now shows a schematic representation of an example of a device for performing the inventive Method in a partially emptied crude oil container 18 with the so-called floating cover 3 lowered onto its stilts 4. It should not be overlooked here that the proportions were chosen completely freely in favor of good presentation. The cover is sealed all around with sealing material 17 which adheres to the container wall 6 and the cover 3 with fastening material 18. As a result, the sliding gap 7 is sealed from the outside. This seal is not always essential, but it serves possible safety requirements. The sediment layer now located in the space 9 sealed to the outside is shown as an irregular accumulation of a residue. Figures 1 and 1A show examples of measured topographies of sediment layers, as occurs in large storage containers. The container bottom 1 is inclined against a container outlet 5, to which a line 22 is connected for leading away the slurried sediment.

In this example, two liquefaction lances with rotatable nozzles 12 are lowered into the closed space 9 by leaving open working openings 8. According to the method, fresh crude oil or, if necessary, fractions thereof or recirculated solution are injected into the sediment under an adapted pressure of, for example, in the order of magnitude of 5 to 30 bar. In addition to their rotation, the nozzles can also be moved in the direction of arrow Z, which allows a very specific radius to be sprayed. These individual pressure lines 13 are brought together to form a main pressure line 14, which is connected to a multi-way valve 15. The arrangement shown here allows the necessary recirculation and the formation of a strong flow between the nozzles shown in FIG. 3 due to its arrangement.

Although two pumps are used in this example, in principle one can be used. Figure 7 shows this embodiment. A pump 21 is via two reusable cocks 15 and 16, there are 3-way cocks, wired so that on the one hand, if necessary, fresh crude oil or fractions thereof can, if necessary, be passed from the fresh oil container 30̸ via line 32 into the nozzles, or on the other hand, as in Picture shown, recirculation is possible.

The embodiment according to FIG. 6 with two pumps allows better process compensation, in which, for example, new crude oil or fractions thereof can be pumped in without interrupting the delivery in the drainage. It is thus possible to carry out a small recirculation directly back into the nozzles, or in order to obtain a desired dilution, a large recirculation via line 26 into the container 30̸ and from there via line 32 and the first pump 21 and then into the nozzles 12 to execute. The drawn position of the two taps 15 and 16 shows the phase of introducing fresh crude oil or fractions therefrom into the sealed container part 9. For the "small" recirculation, the tap 15 is turned by 180 ° and the second pump 20 ° on, the first Pump 21 switched off. If after a certain time the tap 16 is turned 90 ° clockwise, the drainage takes place in the storage container 30 ', which storage container can also be a different one. This gives you the option of specifying any work cycle; The cocks and pumps, as well as the nozzles, can be controlled via a computer, which in turn uses program-related measurement results from the system for the process.

Such measurement results come from measuring devices such as the viscometer 24 drawn into the drainage lines 22 and 25. Other measuring points are also conceivable that feed the process with data that are used for control and regulation. A filter 23 can also be provided in the drainage in order, for example, to protect such measuring devices and the nozzles measuring in the flow and also to generally clean the slurried solution of foreign particles.

Flow meters can be installed at suitable points to check the yield. If, for example, the fresh amount of crude oil withdrawn through line 32 and the slurry solution returned through line 26, but returned to another storage container, are measured, it can easily be compared how good the yield of the process is. Since the yield measurements can be carried out in many different ways, the arrangement of the flow devices has not been specified in the figures.

There are cases in which, for some reason, the quickest possible cleaning of a container is important and the purity of the recovered crude oil is not so important. In these cases it may be permitted to use a very specific additive in the prescribed amount to accelerate the liquefaction process; these are means which increase the flow rate, reduce the viscosity, etc. Such additives, usually solvents, are determined by careful laboratory tests and their concentration in use; they are then advantageously added to the fresh crude oil or fractions thereof.

FIG. 5 shows in the diagram as a device a plurality of individual nozzles connected to form a controlled vortex system. Each rotatable, liftable and lowerable nozzle head 10̸ is schematically drawn with three inputs: an input for the crude oil to be injected, an input for pressurized fluid, for example compressed air or pressurized oil for counterclockwise rotation and an inlet for pressurized air or pressurized oil for clockwise rotation. The compressed air or the pressurized oil is switched on via an L / R distributor (L / R = left / right). A common liquid pressure line supplies all nozzles, a common fluid pressure line supplies all L / R distributors. The L / R distributors are, for example, switchable pneumatics or hydraulic blocks, the control lines of which are connected to a multiplex circuit. The multiplexer is computer controlled and capable of switching several addressed outputs simultaneously. In FIG. 5, each pair of vertebrae is illustrated at different heights; the outputs activated on the L / R distributor are marked with an asterisk. An n-line connected to the MUX should indicate that the number of nozzles to be operated can be freely selected.

As a further embodiment, FIG. 8 shows a device of the type that can be used in storage containers with a fixed cover, the so-called firm roofs. Such a storage container 80̸ has usually distributed a number of manhole entries 81 around its circumference, one of which is shown in the drawing. How to proceed with storage containers with a fixed cover is discussed in detail below in connection with FIGS. 12 and 13. However, a special case has to be considered separately. It can happen that the thickness of the sediment layer, i.e. the height of the sediment, completely obscures such an opening and prohibits the intended opening of the closure and that roof openings are either not available or cannot be used for any reason. In this case, such a Manhole 81, a collection tank 82 is tightly attached, which begins to fill with oil sludge after successive, partial opening of the manhole cover. A conveying line 83 connected to the collecting tank 82 with a screw conveyor 84 conveys the oil sludge swelling into the collecting tank into a preferably mobile liquefaction tank 85, which is only shown here in a stylized manner, into which the liquefaction lances can then be introduced. The oil sludge mixed and liquefied therefrom with the supplied crude oil or fractions is led away via a line 87. According to the description according to the devices of FIG. 6 or 7, a recirculation can take place via the line system 86, as well as filtering via a filter 88, viscosity measurement with a device 89 etc. in the outgoing line system 87. With 90̸ a recirculation line is designated, with 91 and 92 each a 3-way valve, 95 and 96 are pump units and the fresh oil supply is designated with 93, the removal, for example. for warehousing or for refinery with 94. In general, what has been said in connection with FIGS. 6 and 7 applies to this special embodiment of the device shown in FIG.

A liquefaction lance will now be discussed in more detail below. A single or several liquefaction lances of this type, which are combined by control to form a vortex system, essentially form the instrument with which crude oil or fractions thereof are injected into a container as a liquefying agent and as a carrier of the kinetic energy, so that the oil sludge sediments can be liquefied. Each lance is essentially formed by a pipe system and a nozzle. The pipe system connects the vertically adjustable nozzle to a supply line, via which the nozzle is fed with the pressurized crude oil or fractions therefrom. In the preferred embodiment, the nozzle is used for actually injecting this crude oil or fractions therefrom into the sediments. Each nozzle head of the lance can be Fig. 9 with a single or gem. Fig 10̸ be equipped with two alternative nozzle heads.

A rotary nozzle 10̸1 acc. Fig. 9 has a distribution head 10-2, which is rotatably mounted on a tubular connector 10-3; in the present embodiment, the bearings are carried out with the help of ball bearings 10̸4, but other bearings, such as roller bearings or plain bearings, etc., can also be provided. Two securing elements 10̸5, for example yoke rings, hold the two parts which can be rotated relative to one another in the axial direction. The connector 10-3 in turn is fixed, for example by a thread, to the inlet end of the pipe system, not shown. The distribution head 10̸2 has a central cavity 10 ,6, in which several bores 10̸7 open, the axes of which point in different spatial directions. In each bore 10̸7 a sleeve 10̸8 protruding beyond the distribution head 10̸2 and forming the actual nozzle mouth is inserted; these sleeves, which are subject to heavy wear, can be detached in a simple manner, for example with the aid of a screw connection, and can therefore be replaced. It is essential for the function of this nozzle that the axes of the bores 10̸6 are not directed radially or axially with respect to the distribution head 10̸2, but that at least one bore axis has a tangential component for the rotary drive.

The crude oil or fractions from it is conveyed by the pump into the pipe system of the liquefaction lance and passes through the tubular connector 10̸3 into the cavity 10̸6 of the distributor head 10̸2, and exits from there through the holes 10̸7 into the container. Because the holes are like this are directed that the oil has at least one tangential speed component, the nozzle is rotated by the reaction. As already mentioned above, this means that the oil streams injected into a storage container wash practically every point, even those that are difficult to reach through the installation of containers.

FIGS. 10̸ and 11 show nozzle heads with two superimposed rotary nozzles 110̸ and 111, which are fastened to a connecting piece 112 in approximately the same way as in FIG. 9, this connecting piece being axially longer and projecting through the nozzle heads. The nozzle heads also each have an annular cavity 113, in which outlet bores 114 open with nozzle sleeves 115. These bores 114 are directed in such a way that, when oil flows out, they can set the relevant nozzle heads in rotation in different directions. Arranged in the interior of the connecting piece 112 and coaxially thereto is a control piston 116 which is vertically displaceable with respect to the connecting piece and which here has an axially directed outlet nozzle 112. This axially directed opening is rotationally invariant, it is used here as an additive to increase the total hydrodynamic energy.

In the embodiment according to 10̸, the control piston 116 has one or more radial openings 117 at the height of the upper rotary nozzle 110̸, which can be aligned with the corresponding openings 118 of the connecting piece when the piston is rotated, which openings 118 in turn open into the annular cavity. At the level of the lower rotary nozzle 111, the tube 116 also has one or more openings 119, which can be aligned with corresponding openings 120̸ of the connecting piece. The Tube 116 can be rotated from a closed position into a first flow position, specifically in such a way that the openings 117 and the openings 118 are aligned, or else into a second flow position, such that the openings 119 and 120̸ are aligned. Depending on one of the three positions of the tube, one or the other nozzle head is pressurized with pressure oil, so that the same liquefaction lance can produce oil vortices in different directions of rotation. In this case, the tube 116 is open at the bottom and the connecting piece is provided at the bottom with a further nozzle orifice 121 pointing downwards.

Another embodiment for the control of the direction of rotation is shown in the arrangement according to FIG. 11. Here, the control piston 130̸ is rotatable instead of about its axis, it can be displaced vertically along; it also has oil passage openings 131 only at a height. The connecting piece in turn has openings 132 aligned with it, on the one hand at the height of the upper and openings 133 at the height of the lower rotary nozzles. In this case, the control piston is closed at the bottom. It can be displaced vertically such that it either assumes a closed position in which its openings 131 are covered by the connecting piece 112 so that no oil can flow out, or that it assumes a first flow position in which the openings 131 and 132 are aligned, or that it assumes a second flow position in which openings 131 and 133 are aligned. In the last two positions, one of the rotary nozzles is supplied with oil, so that the liquefaction lance can also generate vortices of different directions of rotation. In this arrangement described last, the control piston 130̸ and the connecting tube 112 are closed at the bottom because the downward nozzle orifice is omitted.

Known means can be used to adjust the control piston. In both embodiments according to FIG. 10 and FIG. 11, a screw adjustment that can be operated by hand is specified. A sleeve 140̸ which is firmly connected to the control piston 116 or 138 is fitted into an annular groove 143 of an adjusting wheel 141 with an annular adjusting handle 142. In the event of only rotation without axial displacement (FIG. 10̸), sleeve 140̸ and annular groove 143 are fixedly connected to one another and the adjusting wheel 141 has no means for axial displacement along the connecting piece 112. In the event of an axial control displacement (FIG. 11), the sleeve 140̸ runs freely in the sliding groove 143 and, for example, a helix 145 is provided on the connecting piece 112, along which the adjusting wheel 141 can run and thereby pull the control piston 130̸ attached to the sleeve 141 in the axial direction .

Figure 12 now shows a device according to the invention for use in storage containers with a fixed cover with a liquefaction lance, which can be partially transversed with the help of a hollow joint in the container space. In the stretched state, the liquefaction lance 10̸0̸ with the rotating nozzles 10̸1 and recoil nozzles 163 on the lance front part 161, which is connected to the lance shaft 160̸ via the hollow joint 162, can easily be inserted through a mostly existing central opening 180̸ in the lid of the container 80̸ '. In order to position the lance front part 161 transversely after the lance has been inserted, a cable pulling device is provided in which a metal cable 165 is attached to a fastening 164 on the lance front part 161 and runs over a roller 166 arranged on the lance shaft 160̸. The rope 165 is wound up or unwound via a winding drum 167. A suitably sturdy support bracket 168 holds the lance shaft 160̸ and the winding drum 167 in this way via a ball bearing 169 ' stored that the entire liquefaction lance 10̸0̸ can be rotated in one direction or the other according to the arrow Z. The oil feed 170̸ is also rotatably supported by another bearing 169. With this schematic representation, you always have to be clear that the actual size relationships are strongly recorded. The container can have a diameter of, for example, 50 μm and the lance shaft, however, only from 10 to 20 cm, that is a ratio of 5'0̸0̸0̸: (1-2). The length of the lance shaft is 16-17m and the length of the front part of the lance is approx. 20̸-25m. In this size ratio, the trestle is also to be understood and above all, this note is still important for what is stated below.

The two bearings 169 are designed in a similar bearing technology, preferably ball (169 ') or roller bearings, as in the case of the rotating nozzles according to FIG the liquefaction lance is rotated by the transversely positioned front part 161 with the recoil nozzles 163 pointing in the same direction by the liquefying agent flowing out under pressure. The transverse positioning of the lance front part 161 to the lance shaft 160̸ takes place by means of the cable pull described; to pull out the lance, the cable is loosened and the front part of the lance drops due to the action of gravity until it is linear to the shaft. The hollow joint connecting the two parts is designed according to the prior art.

It can be seen from FIG. 12 immediately that the conical nozzle action (see FIG. 4) of a plurality of rotary nozzles 10-1 on the 20-25 m long lance front part 161 and the simultaneous sweeping over of the sediment topography 2 with the horizontal one swung out lance front part by rotation around the lance shaft axis, the whole amount of sediment can be sprayed. It is therefore possible with this device to process 180̸0̸ to 190̸0̸ m2 sediment in practically one operation. As mentioned, this embodiment of a liquefaction lance with a multiple number of nozzles and with the swiveling device for storage containers with fixed covers is provided. This embodiment can also be seen as a specialized one for vertical insertion into the container.

A further special embodiment of the device for use in storage containers with fixed covers is shown in FIG. 13. It is a specialist for horizontal insertion into the container. The insertion takes place through lateral manhole openings 81, 81 '. Instead of a hollow joint 162, this embodiment has a rotary projection 171, around which the lance front part 161 can be rotated, as is shown by the rotary arrow Z. This lance front part 161 is equipped approximately the same as that shown in Figure 12; a plurality of rotary nozzles 10-1 serve to liquefy the sediment, recoil nozzles 163 set the lance front part 161 in rotary motion by the impulse of the liquefying agent flowing out. The lance front part itself is rotatably mounted on a right-angled tube extension on the lance shaft 160̸, as was mentioned in connection with FIG. 12, on the rotatable projection 169 of the liquefier supply 170̸. Here, too, a similarly designed rotary attachment 169 with ball or roller bearing 169 'is provided for the rotatable mounting of the front part of the lance. Because of the horizontal position, a support 172 is additionally required, which is shown only schematically here. Secure and tilt-free support of the liquefaction lance with dimensions as discussed in connection with FIG. 12 can be regarded as being removable from the prior art.

In this embodiment, it is immediately apparent that the entire sediment topography cannot be processed in a single operation. The liquefaction lance will have no effect in the area of the support and beyond. It is therefore envisaged to insert the liquefaction lance through the manhole openings which are also present (as a rule) in a plurality of successive work steps. Thus, dimensions of the lance front part 161 are advantageously used, which correspond approximately to 1/3 of the container diameter. It follows that the lance shaft is about 2/3 of the same. Expressed in dimension values, this results in approx. 15-20̸m for the lance front part 161 and approx. 30̸-40̸m for the lance shaft 160̸. It is roughly the inverse proportions of the embodiment for vertical insertion.

The number of the rotating nozzles 10-1 arranged on the front part 161 of the lance is measured by the effective diameter of the nozzle itself (see also FIG. 4). As a rule, 5 nozzles, which are arranged at an even distance, are sufficient. the recoil nozzles 163 are placed in the spaces, 4 of which are usually sufficient.

It is of course clear that drainages are also provided in the embodiments according to FIGS. 12 and 13. However, this fact has been dealt with so extensively that it is tacitly assumed here and omitted to relieve the burden on the presentation.

Claims (22)

1. Process for the recovery of compacted or compressed crude oil (bound in residues) or refinery products obtained therefrom by liquefaction, partly comprising thixotropic residues essentially constituted by sludge-like, compressed and sedimented crude oil or refinery products recovered from crude oil and which have sedimented in storage or transportation containers to a more or less compact deposit and in which for dissolving such residues a chemically affine liquefying agent is jetted in under pressure at several points of the container, characterized in that the hydrodynamic energy introduced by the jetting process is distributed into a liquid layer over the entire sediment by planned flow formation, by bringing it into a system of fluid eddies in such a way that by at least two flow generators constructed in this way contrarotating eddies are formed, between which flows form, with whose hydrokinetic energy the oily deposit is successively returned to the originally liquid aggregate state.
2. Process according to claim 1, characterized in that by a plurality of individual eddies matched to one another in the rotation direction hydrodynamic energy is added to superimposed, controlled flows having a loosening, suspending and dissolving action on the sediment relief.
3. Process according to claims 1 or 2, characterized in that the fluid transferring the hydrodynamic energy is jetted by means of pivotable and/or rotatable nozzles and the components of the sediment transferred into the liquid phase are sucked off by drainage.
4. Process according to claim 3, characterized in that at least part of the liquid phase removed by drainage is reused for further jetting.
5. Process according to one of the claims 1 to 4, characterized in that the liquefying agent is removed from the liquid layer above the sediment.
6. Process according to claim 4, characterized in that the liquid phase removed by drainage is checked with respect to its viscosity level and is recycled for jetting until a predetermined viscosity threshold is reached.
7. Process according to claims 5 or 6, characterized in that fresh crude oil or a refinery agent obtained from the crude oil is added to the liquefying agent.
8. Process according to one of the claims 1 to 5, characterized in that prior to the liquefaction of thickened residues from the deposits of a storage container portions are transferred into a special liquefaction container and in said second container brought into the original liquid form.
9. Process according to claim 6, characterized in that material is transferred from the deposits of the storage container by continuous screw conveying from said storage container into the liquefaction container.
10. Process according to one of the claims 3 to 8, characterized in that liquid from the drainage and containing liquefying agent and liquefied sediment, is supplied for crude oil processing.
11. Process according to claim 10, characterized in that the drainage liquid is supplied to an oil refinery.
12. Apparatus for performing the process according to claim 1, characterized in that it has an arrangement of at least two liquefaction lances with eddy-producing nozzles (A₂₂,A₃₃) functionally connected by means of a control (µP,MUX,L/R) and which are arranged and operated in such a way that the hydrokinetic energy jetted directly by the nozzles into a liquid medium can be successively transferred into an eddy system for forming a planned flow (F).
13. Apparatus according to claim 12, characterized in that it has an arrangement with a plurality of liquefaction lances with eddy-producing nozzles (A₁₁ ..... A₄₄), which are so arranged in vertical and/or horizontal manner in a reciprocal interactive spacing over the storage container cross-section, that the hydro-kinetic energy introduced is transferred into a plurality of planned acting liquid flows (F₊,F₋).
14. Apparatus according to claims 12 or 13, characterized in that the nozzles (10,12,13,14) are arranged on raisable and lowerable lances.
15. Apparatus according to one of the claims 12 to 14, characterized in that control means (µP,MUX,L/R) are provided for controlling the position and the rotation of each raisably, lowerably and rotatably constructed nozzle (10,12,110,111).
16. Apparatus according to one of the claims 12 or 13, characterized in that pumps (20) and deflecting valves (16) are provided for pumping out or round the liquefied residues from the container area, either for recirculation or for transferring into another container.
17. Apparatus according to one of the claims 12 to 16, characterized by an eddy-forming nozzle or jetting means (101), which is rotatable about an axis (A) and has several nozzle ends (108) directed in different directions in space, whereof at least one is so inclined away from the radius that it has a tangential component for the rotary drive.
18. Apparatus according to claim 17, characterized in that the jetting means is provided with a hollow pin-like connection (103) for connection to a supply and lance tube (103) and has a distributing head (102) connected in rotary manner therein and having a cavity (106) from which pass to the outside openings (107) for the nozzle ends (108).
19. Apparatus according to one of the claims 16 or 17, characterized by two nozzle heads (110,111), whose nozzle ends (115) are so arranged that their tangential components are directed in opposition and by a control means (116-120,130-133,140-145) for the alternative supply of crude oil or fractions thereof to the nozzle ends (115).
20. Apparatus according to one of the claims 14 to 19, characterized by a liquefaction lance (100) with a lance shaft (160) and a lance front part (161) movable relative thereto and having a plurality of rotary nozzles (163) for jetting out the crude oil or fractions thereof.
21. Apparatus according to claim 20, characterized in that means (169,169') are provided for rotating the liquefaction lance (100) with the lance front part (161).
22. Apparatus according to claim 21, characterized in that the drive means (163) are thrust nozzles operable with the crude oil or fractions thereof and which are located on the lance front part (161).

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