WO1995015287A1

WO1995015287A1 - Apparatus for heating and discharging of a reservoir

Info

Publication number: WO1995015287A1
Application number: PCT/FI1993/000522
Authority: WO
Inventors: Seppo Sainio; Tom Främling; Timo Räisänen
Original assignee: Neste Oy
Priority date: 1993-12-03
Filing date: 1993-12-03
Publication date: 1995-06-08
Also published as: LV11607B; LV11607A; RU2110464C1

Abstract

The present invention is related to a heating/emptying apparatus for tanks or containers containing high-viscosity products, in which apparatus the product is rendered pumpable by heating. The apparatus comprises a suction/pumping unit (9) lowerable to the interior of the tank (1), a heat exchanger unit (11) external to the tank (1) and piping (21, 28) for circulating the product between the suction/pumping unit (9) and the heat exchanger unit (11). The suction/pumping unit (9) comprises a pump assembly arm (14) incorporating a pump (16), a pump-rotating drive means (15), and mounted by a pivotal joint to the upper section of the pump assembly arm (14), one or a greater number of jet pipes (17) suited for discharging the oil product heated in the heat exchanger unit (11) to the interior of the tank (1).

Description

APPARATUS FOR HEATING AND DISCHARGING OF A RESERVOIR.

The invention is related to a heating/emptying apparatus for high-viscosity products stored in a tank or container. The invention is particularly related an apparatus suited for emptying such products from containers at a viscosity too high for pumping.

Heavy oil products, for instance, are known to have a very high viscosity. In cold climates and particularly in freezing conditions, such products are practically in the solid state, making their pumping impossible. This problem is particularly difficult when the tanks are located outdoors and the emptying of the tanks must occur as rapidly as possible, as is the case in rail transport of heavy oil products.

Therefore, removal of high-viscosity products from a tank requires lowering the viscosity of the product by heating. The heating of large tanks without mixing the con¬ tents is extremely slow, because the heat must be transferred by conduction. However, mixing is not possible without first reducing the product viscosity by heating.

In prior-art arrangements the heating of the product has been implemented by introduc- ing an external liquid which is mixed into the product and the mixture is then circulated between the tank and a heat exchanger. Thus, e.g., US patent 4,287,903 discloses a method and apparatus for removing a heavy oil product from a tank located in a cold environment, e.g., from a sunken ship. According to the patent, from a floating ship is lowered a pipe which is connected to a jet pipe that further is inserted into the ship tank through the deck. Water heated in the floating ship is injected via the jet pipe into the ship tank, whereby the water heats the viscous oil contained in the tank. The pumpable oil/water mixture thus forming in the tank is pumped from the upper part of the tank to ship floating above via another pipe. The oil is next separated from the water, which is subsequently first taken to the heat exchanger and then recirculated to the tank of the sunken ship via the jet pipe.

The tank emptying apparatus disclosed in cited US patent 4,287,903 has several serious drawbacks. Water as a heating medium spoils the product being removed from the tank. Although a major part of the water could be separated relatively easily, the reduction of the water content in the remaining product to a level acceptable for salable product grades is difficult and very expensive. Moreover, apparatuses suited to such separation of water in, e.g., rail transport do not exist at all. Further, the use of fixed jet pipes is inefficient, because the stirring effect is weak when a liquid is injected in another liquid, namely, in an oil/water mixture as occurs in the present case. An additional disadvantage in the apparatus according to cited patent is the high negative suction head, which makes the system sensitive to leaks and causes extra wear on pumps due to cavitation, as well as high specific power consumption.

The present invention provides an apparatus for emptying high-viscosity products from tanks without the above-described disadvantages. Accordingly, it is an object of the in¬ vention to achieve a heating/emptying apparatus for tanks, said apparatus being easily transportable and thus being extremely well suited for use in cold climates in the emptying of, e.g. , tank cars used in rail transport. It is another object of the invention to achieve a heating/emptying apparatus for tanks, said apparatus not using water or other media for heating the contents of tank. It is a third object of the invention to achieve a heating/emptying apparatus for tanks, said apparatus integrating the elements for heating/mixing the tank contents into a single, readily transportable unit. It is still another further object of the invention to achieve a heating/emptying apparatus for tanks, said apparatus being suited without modification for emptying both extremely heavy/viscous and light products from different types of tanks or containers.

To achieve the above-mentioned objects and others, it is possible by virtue of the present invention to provide a heating/emptying apparatus for particularly removing high-viscosity products from tanks or containers, in which apparatus the product is rendered pumpable by means of heating. The apparatus according to the invention is characterized in that the apparatus comprises a suction/pumping unit lowerable to the interior of the tank, a heat exchanger unit external to the tank and piping for circulating the product between the suction/pumping unit and the heat exchanger unit. The apparatus according to the invention is based on using the product contained in the tank for heating/stirring the tank contents, whereby a sufficiently low viscosity for the removal of the product from the tank is attained. To this end the principal components of the apparatus according to the invention comprise a suction/pumping unit lowerable to the interior of the tank via the tank fill hole or manhole; a heat exchanger unit external to the tank for heating the product; and piping for circulating the product between the suction/pumping unit and the heat exchanger unit so long as to heat the entire contents of the tank to a sufficiently low viscosity for circulation pumping and finally pumping out from the tank.

According to the invention, the suction/pumping unit comprises a pump assembly arm incorporating a pump, a pump-rotating drive means, and mounted by a pivotal joint to the upper section of the pump assembly arm, one or a greater number of jet pipes suited for discharging the oil product heated in the heat exchanger unit to the interior of the tank at a high velocity.

Advantageously, the pump is mounted to the lower end of the pump assembly arm. Such an arrangement achieves several benefits over tank-emptying systems having the suction pump located to the outside of the tank. Firstly, the negative suction head remains insignificantly small, and secondly, the product is transferred out from the tank at a positive pressure, not at a partial vacuum. Thus, leak problems associated with a high negative suction head and cavitation effect in the pump are avoided. Further, the product transfer piping can be implemented using conventional pipe or hose types, instead of expensive hoses designed for a vacuum.

In the apparatus according to the invention, the pump is advantageously driven by a hy¬ draulic or pneumatic motor. Then, the ignition hazard of the product is entirely elimin¬ ated, which in the case of using electric motors would require special constructions with explosion-proof enclosures to prevent spark hazard. Moreover, the use of a hydraulic or pneumatic motor achieves stepless pump speed control. Although the pump itself can be selected from a great number of different constructions, rotating positive displacement pumps are particularly advantageously employed in the apparatus according to the invention. Such an internal screw pump construction has a rotor as the rotating element, complemented with a stator as the stationary element, whereby the former element is mounted rotatingly on bearings. The rotor is shaped as a true helical screw with an extremely coarse pitch, great thread depth and small value of minor diameter. The stator has a double helical thread with a pitch twice that of the rotor. Thus, the stator and the rotor, which both rotates in the interior thereof and additionally performs an eccentric movement by virtue of universal-jointed connecting rod, can form closed transfer spaces for the material being pumped, said spaces continuously travelling from the inlet side to the outlet side.

Such a pump assembly comprises an extremely compact, elongated unit which is easy to adapt to the interior cavity of the pump assembly arm casing so that the actual pump unit is situated at the lower end of the arm, wherefrom it is connected by means of a shaft to a motor situated at the upper end of the pump assembly arm.

According to the invention, the upper end of the pump assembly arm has mounted via a pivotal joint at least one, advantageously at least two jet pipes. Particularly in conjunction with the emptying of tanks of circular cross section, the number of the jet pipes can be greater if so desired. The jet pipes are rotatable about a pivotal joint between two extreme positions. In one of the extreme positions, the jet pipes are turned parallel with the pump arm, while in the second extreme position the pipes are turned to point orthogonally sideways or even slightly upward inclined. As is described later, the former extreme position is used when inserting the pump assembly arm into the tank and starting the heating/stirring phase. With the gradual heating to the tank contents, the jet pipes can be rotated sideways about the pivotal joint to a more orthogonally oriented position.

The movement of the jet pipes is advantageously arranged by means of hydraulic or pneumatic cylinders in a conventional manner. The actuator comprising, e.g., one or a greater number of hydraulic or pneumatic cylinders can be adapted to the upper end of the pump assembly arm, either to its interior or, rather, advantageously to its exterior. The movement of the jet pipes can also be implemented using mechanical or electromechanical actuators such as, e.g., linked levers or assemblies comprising screw-electric motor combinations. However, with the help of the hydraulic or pneumatic cylinders it is easier to implement the function in which the jet pipes are turned sideways and upward only when the viscous resistance imposed by the product being handled does not exceed a preset value.

According to the invention, to the ends of the jet pipes are adapted one or a greater number of nozzle elements, by means of which the heated product discharged from the jet pipe can be directed in different directions at a high velocity. Thus, faster heating of the product as well as transfer of the heated product into all parts of the tank is achieved.

The required length of the jet pipes from the pivotal joint to the distal end of the jet pipe is determined by how far the nozzles extend sideways. The length of the jet pipes is advantageously selected so long as to leave the jet pipe ends in their lowered position slightly higher than the lower end of the pump assembly arm. This is advantageous when commencing the heating of the tank contents and lowering the pump assembly arm into a high-viscosity, even almost solid product.

According to a preferred embodiment of the invention, the lower end of the pump as¬ sembly arm, which incorporates the inlet opening to the pump, is provided with a heat¬ ing means. Such a heating means is advantageously implemented in the form of an electric heater element. The heater element can be placed to the interior of pump as¬ sembly arm lower end, more specifically, close to the inlet channel of pump, on the wall of the arm lower end, or to the inside of the wall. Further, the electric heater element, or a heater assembly containing the same, can heat the product either directly or via a heat-transfer medium such as oil. This kind of a preheating facility is necessary at the start of the heating operation as the pump assembly arm is being introduced to the interior of the tank. Then, the product enclosing the lower end of the arm can be heated by a sufficiently large volume to commence the pumping of the product to a heat exchanger unit. According to the invention, to the upper end of pump assembly arm are connected pipes or hoses for pumping the product to a heat exchanger unit, and respectively, returning the heated product back to the tank via the jet pipes. Accordingly, the former pipe is connected to the outlet of the pump unit situated in the interior of the pump assembly arm, while the latter pipe is connected to the jet pipes. The transfer of the product between the heat exchanger unit and pump assembly arm can take place via separate pipes. However, according to a preferred embodiment of the invention, a coaxial dual pipe is used for transferring the product. Then, the product heated in the heat exchanger can deliver heat on its return flow along the outer pipe to the tank to the colder product flowing in the inner pipe from the tank toward the heat exchanger. This arrangement shortens the preheating period, whereby the pumping can be commenced with a shorter delay.

The suction/pumping unit according to the invention is advantageously moved with the help of a transfer means suited for transferring the apparatus to the tank fill opening and then lowering the apparatus into the tank and lifting it up therefrom. To this end, the transfer means is formed by an apparatus capable of moving the suction/pumping unit both vertically and horizontally. The transfer means employed is advantageously an articulated boom assembled from a number of pivotally jointed arm sections, whereby the angles between the sections can be altered with the help of hydraulic or pneumatic cylinders. The above-described piping arrangement for transferring the product between the suction/pumping unit and the heat exchanger unit is advantageously adapted to run in the piping along the transfer boom, either on its outside, or even more advantageously, in its interior where the piping is better protected. In a similar manner, the interior of the boom can be utilized for routing the piping and cables necessary for the hydraulic/pneumatic or electric powered components of the system.

In the product transfer arrangement, e.g., between the articulated beam and the suction/pumping unit is advantageously adapted a vibration isolator which can be of any conventional type. With the help of the vibration isolator, any pulsations resulting from the pumping action and the movement of the jet pipes or any other cause can be eliminated.

In certain cases it may be advantageous to provide the suction/pumping unit lowered into a tank with an additional means of rotation about its vertical axis. Such a rotation means can be implemented in multiple different ways by, e.g., adapting a hydraulic or pneumatic rotating actuator either to the end of the transfer boom, or alternatively, to the upper end of the suction/pumping unit. Such a function can also be arranged by mechanical or electromechanical means in a number of conventional fashions.

In the following, the invention is described in greater detail with reference to the annexed drawings in which

Figure 1 illustrates diagrammatically a heating/emptying apparatus according to the invention adapted to an unloading station suited to the emptying of an on rails transferrable oil tank;

Figure 2 is a detailed view of the heating/emptying apparatus shown in Fig. 1;

Figure 3 is a diagrammatic view of a suction/pumping unit according to the invention; and

Figure 4 is a diagrammatic view of an arrangement for moving the jet pipes.

With reference to Fig. 1, an unloading station for railroad tank cars is shown having a tank car 1 parked at an unloading dock structure 2. To the dock structure is fixed a support column 3 having mounted at its upper end supported by means of a rotatable support arrangement 4 a transfer boom 5, whereby the support arrangement 4 facilitates the rotation of the transfer boom 5 about its vertical axis of rotation. The transfer boom 5 is advantageously constructed from a number of boom sections 6, 7 which are connected to each other by means of pivotal joints, whereby the angle between the boom sections is alterable with the help of hydraulic cylinders 8. The transfer boom 5 supports a suction/pumping unit 9 shown lowered into the interior of the tank car 1, said unit further carrying vertically pivotally rotatable jet pipes 17. On the unloading dock structure 2 is further located an equipment cabinet 10 housing a heat exchanger unit 11 for heating oil products and a hydraulic machinery (not shown) for driving the hydraulic components of the system. The support arrangement 4 can be mounted to the support column 3 at a fixed height, or alternatively, its mounting height may be adjustable. By a proper arrangement of the hydraulic cylinders 8, an articulated transfer boom 5 can equally well be replaced by a boom constructed from fixed boom sections provided that the transfer boom 5 is capable of moving the suction/pumping unit 9 to above the unload/fill opening 12 of the tank car 1 being emptied, as well as lowering the unit to the interior of the tank car. It must be further noted that the entire heating/emptying apparatus shown in Fig. 1 can be placed onto a movable under¬ carriage if desired.

With reference to Fig. 2, the heating/emptying apparatus according to the invention is shown in greater detail. The transfer boom 5, which is rotatably mounted by means of the support arrangement 4 to the support column 3, is comprised of boom sections 6, 7 which are connected to each other by means of pivotal joints, whereby the angle between the boom sections is alterable with the help of hydraulic cylinders 8 to the end of lifting/lowering the suction/pumping unit 9 mounted to the distal end 13 of the transfer boom 5. As seen in the diagram, the suction/pumping unit 9 lowered via the hole 12 into the tank 1 comprises a pump arm 14 having at its lower end mounted a transfer pump 16 driven by means of hydraulic motor 15 and a shaft (not shown). To the upper end of the pump arm 14 are pivotally mounted jet pipes 17, shown in the diagram turned upward close to the upper extreme position. During lowering the suction/pumping unit 9 into the tank 1, the jet pipes 17 are held turned downward.

Further in Fig. 2, it is denoted by arrows 18 the flow of the oil product which is rendered pumpable by heating, from the lower end of the pump arm 14 into the pump 16, and further therefrom, in the direction indicated by arrows 19, upward to the upper end of the pump arm 14, wherefrom it is routed out via an outlet pipe 20. Denoted in dashed line 21 is the flow of the oil further in the piping adapted to the interior of the transfer boom 5 to a pipe 22 ending at a heat exchanger 11. Heat to the heat exchanger 11 is introduced in the form of a suitable medium such as hot steam or water via a valve 23 and a pipe 24. After delivering its heat content, the cool medium is taken away from the heat exchanger 11 via a pipe 25 and a valve 26.

In the heat exchanger 11 the temperature of the oil product is elevated to a temperature determined by the required viscosity reduction for the oil product in the specific conditions. However, to attain the shortest possible emptying time for the tank 1, the oil product is advantageously heated to a maximal temperature not yet causing detrimental changes in the properties of the oil product. Generally, a proper temperature range for the heated product is 50-150 °C.

With still further reference to Fig. 2, the oil product heated in the heat exchanger 11 is taken via a pipe 27 and a pipe 28 running in the interior of the transfer boom 5 as denoted by dashed line 28 to the suction/pumping unit 9, and therefrom via pipes 29 and jet pipes 17 to the tank 1. In the diagram there are denoted by reference numerals 30, 31 two oil product jets aimed to discharge in two different directions, whereby the jets effectively distribute the heat transferred along with the heated oil product to all parts of the tank 1. Further shown in the diagram is a product discharge pipe 33 connected to the inlet pipe 22 of the heat exchanger 11 via a valve 32, said discharge pipe serving for derouting the product rendered pumpable to a site of use or other storage tank by means to be described later in detail.

With reference to Fig. 3, the different components of the suction/pumping unit 9 according to the invention and the connections between them are illustrated in a diagrammatic manner. In the diagram is shown lowered into the oil product tank 1 the suction/pumping unit 9 comprising a pump assembly arm 14 and jet pipes 17 pivotally mounted to said arm 14, said pipes being shown in the diagram in their lowered position. To the interior of the pump assembly arm 14, close to its lower end is adapted a pump 16, which advantageously is a rotating positive displacement pump such as an internal screw pump, for instance. The pump 16 is rotated via a shaft 34 by a hydraulic motor 15 mounted to the upper end of the pump assembly arm 14, the hydraulic oil supply inlet and outlet lines to said pump being denoted in the diagram by reference numerals 35 and 36, respectively.

To the lower end of the pump assembly arm 14 is advantageously adapted a heater ele- ment 37, e.g., an electric heater serving to the end of providing sufficient initial heating of the product to facilitate the lowering of the suction/pumping unit 9 into a solidified or almost solidified oil product at the start of the emptying operation of the tank, and to convert the product into a pumpable form prior to starting the pumping to the heat exchanger 11. Accordingly, the lower end of the pump assembly arm 14 provides a preheater end 38 with a extremely useful function particularly at the start of the heating operation. The heater element 37 can be located to, e.g., inlet opening at the lower side of the pump 16, or alternatively, to the wall of the lower end 37 of the pump assembly arm 14, or to the inside of the wall. Obviously, the lower end 38 of the pump assembly arm 14 can be equipped with a strainer (not shown) to prevent the entry of foreign objects or aggregations of the oil product into the pump 16.

To the upper end of the pump assembly arm 14, pivoting at points 39 are mounted jet pipes 17. Thus, the jet pipes 17 can be turned upward and downward about the pivot points 39. In their upper position the jet pipes 17 subtend with the pump assembly arm 14 an angle α, whose maximum value is determined by the internal height of the tank 1, the length of the jet pipes 17 and the height difference between the pivot points 39 and the uppermost inside point of the tank 1. Generally, it is sufficient to make the jet pipes 17 upwardly rotatable to at least 90° angle with respect to the pump assembly arm 14, that is, directly orthogonal to said arm, while a slightly larger elevation angle is also feasible.

With a further reference to Fig. 3, the flow of the oil product is shown passing via the preheater end 38 and the pump 16, then upward within the interior of the pump assembly arm 14, next routed out via, e.g., a pipe 20 and further along transfer piping 40 to the heat exchanger 11. The transfer piping may be comprised of separate pipes, while advantageously a coaxial dual pipe is used in which an outer pipe 40 houses a return pipe 41 running back from the heat exchanger 11. Then, the hot oil product flowing in the inner pipe 41 heats the considerably colder product running in the outer pipe, which arrangement achieves faster and more effective heating of the product. From the return pipe 41 the heated oil product is taken via pipes 42 to the jet pipes 17. The ends of the jet pipes 17 are advantageously provided with a nozzle manifold 42 designed to divide the oil flow into multiple jets directed in different angles.

With reference to Fig. 4, a mechanism suited to moving the jet pipes 17 is shown. To the jet pipes 17, spaced at a distance from the pivot points 39, are connected pull/push rods 44 by means of pivotal joints 43, whereby one ends 45 of the rods are pivotally connected to a pull/push action piston rod 47 of a hydraulic cylinder 46. The vertical movement of the pull/push action piston rod 47 is thus imparted via the pull/push rods 44 to the jet pipes 17 forcing them to rotate upward/downward. Obviously, any conventional arrangement can be employed to this end.

With reference to Figs. 1-4, the function of the apparatus shown in these diagrams during the emptying of tank car spaces is as follows. The tank 1 to be emptied is transferred to the unloading dock 2 and the suction/pumping unit 9 according to the invention is lowered with the jet pipes 17 in their lower extreme position to the interior of the tank 1 via the fill opening 12. Heating of the preheater end 38 at the lower end of the pump assembly arm 14 is turned on, thus commencing introduction of heat from the preheater end 38 to the oil product bulk underneath. With the increasing temperature of the oil product, its viscosity is reduced, thus permitting further lowering of the suction/pumping unit 9. When a sufficient volume of the oil product bulk has reached a sufficiently low viscosity for pumping, the pump 16 is started and circulation of the oil product to the heat exchanger unit 11 and thereof back to the tank 1 via the jet pipes 17 is commenced. As the viscosity of the oil product bulk surrounding the pump assembly arm 14 and the jet pipes 17 assumes a sufficiently low viscosity, the jet pipes 17 can be turned from their vertical downward position pointing to the sides. The actual discharge of the contents of the tank 1 via the valve 32 and the pipe 33 can be started when the entire contents of the tank has reached a temperature sufficiently high for pumping. An alternative possibility is to start discharging via the pipe 33 already at an earlier stage than this. Such a procedure may even be advantageous, because it permits the elevation of the jet pipes 17 to above the oil product upper level in the tank at an appreciably faster rate. Then, the oil product jets discharged from the jet pipes 17 meet much less resistance and reach even the most distant points of the tank interior. Accordingly, an appreciable shorter heating time is attained.

While the above description mostly deals with the application of the apparatus according to the invention to the emptying of heavy, almost solidified oil products from tanks, it must be noted that the apparatus according to the invention is suited to emptying of all such products which at room temperature have too high a viscosity for pumping and whose viscosity can be reduced by heating. Moreover, the apparatus according to the invention is also suited to emptying of lighter products having a viscosity sufficiently low for pumping even without heating. Then, the preheating arrangement at the inlet end of the pump assembly arm 14 can be omitted, as well as the heating of the product in the heat exchanger 11 and recirculation thereof via the jet pipes 17 back to the tank 1.

The apparatus according to the invention entirely overcomes the drawbacks associated with the use of auxiliary media, which may be detrimental to the product, for the purpose of reducing the product viscosity. Accordingly, firstly, the product is not brought in contact with any incompatible medium, and secondly, the heating of the system components is implemented without any media, whose use would cause problems in extreme conditions such as cold climates through, e.g., freezing. The apparatus, and particularly, its suction/pumping unit, are characterized by a remarkably compact construction and pumping of the product out from the tank under pressure. Such an arrangement entirely overcomes disadvantages of systems in which the pumping of the product is implemented using pumps external to the tank being emptied, whereby such pumps suffer from sealing problems, as well as pump impeller cavitation and excessive erosion-corrosion resulting thereof.

Claims

1. A heating/emptying apparatus for tanks containing high-viscosity products, in which apparatus the product is rendered pumpable by heating, characterized in that said apparatus comprises a suction/pumping unit (9) lowerable to the interior of the tank (1), a heat exchanger unit (11) external to the tank (1) and piping (21,28) for circulating the product between the suction/pumping unit (9) and the heat exchanger unit (11).

2. An apparatus as defined in claim 1, characterized in that the suction/pumping unit (9) comprises a pump assembly arm (14) incorporating a pump (16), a pump-rotating drive means (15), and mounted by a pivotal joint to the upper section of the pump assembly arm (14), one or a greater number of jet pipes (17) suited for discharging the oil product heated in the heat exchanger unit (11) to the interior of the tank (1).

3. An apparatus as defined in claim 2, characterized in that said drive means is a hydraulic or pneumatic motor (15).

4. An apparatus as defined in claim 2, characterized in that the pump assembly arm (14) additionally incorporates elements for pivotally rotating the jet pipes (17) from their vertical downward position toward a horizontal position.

5. An apparatus as defined in claim 4, characterized in that said elements comprise one or a greater number of hydraulic or pneumatic cylinder(s) (46), or alternatively, of electromechanically functioning actuator means.

6. An apparatus as defined in any of claims 2-5, characterized in that the distal ends of said jet pipes (17) are provided with a nozzle means (42) for discharging the product in one or a number of directions.

7. An apparatus as defined in any foregoing claim, characterized in that the lower end (38) of the pump assembly arm (14) is provided with a heating means.

8. An apparatus as defined in claim 7, characterized in that the lower end (38) of the pump assembly arm (14) is provided with an electric heater element suited for heating the lower end (38) and/or the product either directly or via a medium.

9. An apparatus as defined in any of foregoing claims 2-8, characterized in that said pump (16) is a rotating positive displacement pump such as, e.g. , a screw pump.

10. An apparatus as defined in any foregoing claim, characterized in that said suction/pumping unit (9) is supported by an articulated transfer structure (5) movable both vertically and horizontally.

11. An apparatus as defined in claim 10, characterized in that said transfer structure (5) comprises an articulated and/or rotatable transfer boom.

12. An apparatus as defined in claims 10-11, characterized in that the suction/ pumping unit (9) is connected to said transfer structure (5) via a vibration isolating element.

13. An apparatus as defined in claims 10-11, characterized in that the piping (21,28) for recirculating the product is mounted to the inside of the transfer boom (5).

14. An apparatus as defined in any foregoing claim, characterized in that said piping (21,28) is formed by a dual pipe in which the product heated in the heat exchanger unit (11) can deliver heat on its return flow to the tank (1) to the colder product flowing from the tank (1) toward the heat exchanger unit (11).

15. Use of an apparatus defined in any foregoing claim for removing high-viscosity products from stationary or movable tanks such as, e.g., railroad cars and tank trucks.