Tar sands include a combination of clay, sand, water, and bitumen, which is a black viscous mixture of hydrocarbons obtained naturally or as a residue from petroleum distillation. Tar sands can be mined and processed to extract the oil-rich bitumen, and the bitumen can be refined into oil. The recovery of oil from the bitumen in tar sands requires extraction and separation systems to separate the bitumen from the clay, sand, and water that make up the tar sands. Bitumen also requires upgrading before it can be refined. Because it is so viscous, bitumen also requires dilution with lighter hydrocarbons so that it can be transported by pipelines or tank cars.
Aspects of the present disclosure can be better understood with reference to the following drawings. It is noted that the elements in the drawings are not necessarily to scale, with emphasis instead being placed upon clearly illustrating the principles of the embodiments. In the drawings, like reference numerals designate like or corresponding, but not necessarily the same, elements throughout the several views.
As noted above, the recovery of oil from bitumen in tar sands requires extraction and separation systems to separate the bitumen from the clay, sand, and water in the tar sands. Because it is so viscous, bitumen typically requires dilution with lighter hydrocarbons (i.e., diluents) so that it can be more easily transported by pipelines, tank cars, etc. To create a fluid better capable of transportation, bitumen can be mixed with a fluid having a much lower viscosity, creating Dilbit. Natural gas condensate (NGC), for example, is a common diluent used to dilute bitumen into Dilbit. Once diluted into Dilbit, it can be more easily transported by pipeline, rail tank car, or other suitable means. There are other industry dilutions other than Dilbit, such as Railbit, which has less diluent than Dilbit.
A rail tank car or tank wagon is a type of railroad or railway car designed to transport liquid and/or gaseous substances. Once diluted into Dilbit, bitumen can be transported in rail tank cars. Because of the variety of different types of liquids and gases that can be transported in tank cars, different types of tank cars can be pressurized or non-pressurized, insulated or non-insulated, and designed for carrying one or several different types of substances. Depending upon the type of substance it is designed to transport, the interior of a tank car can be lined with glass or another suitable coating to isolate the contents of the tank from the shell of the tank. Tank cars carrying dangerous goods are generally made of different types of steel, depending on the intended cargo and operating pressure. Such cars can also be lined with rubber or coated with specialized coatings for the protection of the tank or to protect the purity of the product being transported.
The U.S. DOT-111 is one example of an unpressurized tank car used in North America. Tank cars built to the U.S. DOT-111 specification should be circular in cross section, having a minimum plate thickness of 7/16 inch and a maximum capacity of 34,500 US gallons. Tank cars built to the U.S. DOT-111 specification can be constructed from carbon steel, aluminum alloy, high alloy steel, nickel plate steel, or another suitable material by fusion welding. Once diluted into dilbit, bitumen can be transported in tank cars such as those built to the U.S. DOT-111 specification, among others.
It would be preferable (e.g., cheaper, safer, less time consuming, etc.), however, to transport bitumen without the need to use a diluting agent, such as NGC. To transport bitumen without a diluting agent, bitumen can be reduced in viscosity by heating. Bitumen can be heated in a variety of ways. According to aspects of the embodiments, bitumen (and/or other substances) can be heated in rail tank cars, truck tank cars, pipelines, etc., using electromagnetic induction.
An electrically conducting object (e.g., a metal) can be heated by electromagnetic fields using electromagnetic induction. Specifically, in electromagnetic induction, an electrically conducting object is heated by eddy currents induced in it by electromagnetic induction. As one example of the process of induction heating, a high-frequency alternating current (AC) can be passed through a wire or coil positioned closely to or wrapped around an electrically conducting object. A high-frequency alternating magnetic field is then generated around the wire or coil and penetrates the electrically conducting object. Due to the high-frequency alternating magnetic field, electric currents, called eddy currents, are generated inside the electrically conducting object. The eddy currents heat the electrically conducing object by the magnetic resistance inherent in the heated object.
For ferrous metals like iron and some types of steel, an additional heating mechanism beyond eddy currents occurs. Particularly, the alternating magnetic field inside the coil repeatedly magnetizes and de-magnetizes iron crystals in the electrically conducting object. This rapid flipping of the magnetic domains causes considerable friction and heating inside the object. Heating due to this mechanism is known as hysteresis loss and is greater for materials having a large area inside their magnetic flux density (B)/magnetic field strength (H) curve. Hysteresis loss can be a large contributing factor to heat generated through induction.
Using induction heating, an electrically conducing object can be directly and rapidly heated without using conduction. Because conduction is not relied upon, there is no need to make contact with the object being heated. Induction heating is used in many industrial processes, such as heat treatment in metallurgy, crystal growth in the semiconductor industry, and to melt refractory metals which require very high temperatures. Induction heating is also used in certain cooktops for cooking.
In the context outlined above, aspects and embodiments of inductively heated tank cars are described. In one embodiment, an inductive heating system for tank cars includes a radially-curved pancake coil, a coil housing that surrounds at least a portion of the radially-curved pancake coil, and a frame structure comprising at least one attachment mechanism to secure the frame structure to an exterior surface of a tank car. The system can also include an induction heating power supply to supply power for inductively heating the tank car using the radially-curved pancake coil. When installed to the tank car, the coil housing is assembled with the frame structure to secure the radially-curved pancake coil to the exterior surface of the tank car. Any number of radially-curved pancake coils can be secured to the exterior surface of the tank car to heat the contents of the tank car through inductive heating.
The tank car 10 can be built to the U.S. DOT-111 specification, for example, or another suitable specification. The tank car 10 can be filled with and used to transport various substances. According to the examples described herein, the tank car 10 can be filled with a substance to be heated such as bitumen, and the inductive heating modules 21-26 can be used to inductively heat the tank car 10 and the substance contained in the tank car 10. Aspects of the inductive heating modules 21-26 are described in greater below with reference to
As shown in
A sparging pump 40 is also shown in
As described in further detail below, the inductive heating modules 21-26 can be permanently or releasably secured to the tank car 10. Each of the inductive heating modules 21-26 can include one or more radially-curved pancake coils. When the alternating current from the inductive power supply 30 is electrically coupled to the radially-curved pancake coils, the radially-curved pancake coils generate alternating magnetic fields which induce eddy currents in the tank hull of the tank car 10. The alternating magnetic fields lead to resistive and/or hysteresis losses in the tank hull of the tank car 10, heating the tank car 10 and the contents of the tank car 10.
The alternating magnetic fields can heat the tank car 10 and the contents of the tank car 10 relatively quickly and to a relatively high temperature as compared to other conventional methods, such as using steam. The alternating magnetic fields can also be used to heat the tank car 10 and the contents of the tank car 10 to a desired temperature with relative accuracy and level or repeatability as compared to conventional methods. When heated, the contents of the tank car 10, such as bitumen, Dilbit, or Railbit, can be on-loaded and off-loaded more quickly.
Although not shown in
If the contents of the tank cars 10 and 50 is relatively viscous, such as the case with bitumen, the contents can be heated within the tank cars 10 and 50 using the inductive heating modules 21-26 or the inductive heating modules 61-66. In that way, it can be possible to reduce the viscosity of the contents of the tank cars 10 and 50 to a level that it can be relatively easily poured into and out of the tank cars 10 and 50. Thus, it can be possible to transport bitumen and other viscous substances without the need to use diluting agents, saving significant costs.
To further illustrate the concepts of the embodiments,
The axially-extending coil 120 is provided an example of a coil other than a radially-curved pancake coil for inductive heating. The axially-extending coil 120 can be wrapped around the circumference of the exterior of the tank 100 and extend (e.g., wrap) about any portion of the longitudinal length L of the tank 100.
The radially-curved pancake coils 110-116 and the axially-extending coil 120, any of which can be omitted and/or repositioned, can be formed from any suitable materials for the purpose of inductive heating. In one embodiment, the coils 110-116 and/or 120 can be formed from copper wire or copper pipe, but other types of metals can be used. If formed using pipe, water or another coolant fluid can be pumped through one or more of the coils 110-116 and 120 by a water pump. In that way, the coils 110-116 and 120 can be cooled while being simultaneously used to inductively heat the tank 100. As described in further detail below with reference to
When assembled together, the coils 110-116 and 120 can be positioned closely proximate to but with a gap or mechanical and/or electrical clearance from the exterior surface of the tank 100. To achieve that gap or clearance, the coils 110-116 and/or 120 can be insulated with plastic, rubber, or other suitable materials, encased in plastic, epoxy, or other suitable materials, or spaced-off the exterior surface of the tank 100 using bridges made of wood, plastic, etc.
As shown in
The inductive heating module 500 is designed to be attached or secured to (and removed from) a tank car, such as the tank car 100 shown in
In use, the inductive heating module 500 can be placed up against the exterior surface of a tank car with the curved rails 511 and 512 facing the exterior surface. Before placing the inductive heating module 500 against the exterior surface of the tank car, the levered cam linkage assemblies 531-533 can be actuated to recess the magnetic bars 520 and 521 into the frame structure 510. Once the inductive heating module 500 is positioned at a suitable location against the exterior surface of the tank car, the levered cam linkage assemblies 531-533 can be actuated to extend the magnetic bars 520 and 521 out from (or nearly out from) the frame structure 510. In that configuration, the magnetic attraction from the magnets in the magnetic bars 520 and 521 secures the inductive heating module 500 to the external surface of the tank car, holding it in place for inductive heating. An example of inductive heating modules secured to the external surface of the tank car 100 is shown
The radially-curved pancake coils 550 and 551 can be secured within the frame structure 510 in any suitable manner. To increase the efficiency of induction heating, however, the radially-curved pancake coils 550 and 551 should be secured relatively close (or as close as possible) to the inside panel 560 of the inductive heating module 500. When installed on a tank car, the inside panel 560 of the inductive heating module 500 faces the exterior surface of the tank car. Thus, the radially-curved pancake coils 550 and 551 can be secured relatively close (or as close as possible) to the inside panels of the inductive heating module 500. In that way, the radially-curved pancake coils 550 and 551 can be secured within at least a predetermined spacing to the exterior surface of the tank car to which the inductive heating module 500 is secured.
In some cases, the radially-curved pancake coils 550 and 551 can be surrounded by a coil housing, such as an epoxy or plastic-based casting. The coil housing can be seated and secured within the frame structure 510 to position the radially-curved pancake coils 550 and 551 inside the frame structure 510. In that context, the frame structure 510 and the inside and outside panels 560 and 561 can be used as a casting mold to create the coil housing surrounding the radially-curved pancake coils 550 and 551.
Although not shown in
In some cases, the frame structure 510 can include one or more coil housing seats 540-543, among others, to position and secure one or more coil housings within the frame structure 510. Additional examples of coil housing seats and the manner in which they can be used are described with reference to
The inductive heating module 600 is designed to be attached or secured to (and removed from) a tank car, such as the tank car 100 shown in
In use, the inductive heating module 600 can be placed up against the exterior surface of a tank car with the curved rails 611 and 612 facing the exterior surface. Before placing the inductive heating module 600 against the exterior surface of the tank car, the levered cam linkage assemblies 631-633 can be actuated to recess the magnetic bars 620 and 621 into the frame structure 610. Once the inductive heating module 600 is positioned at a suitable location against the exterior surface of the tank car, the levered cam linkage assemblies 631-633 can be actuated to extend the magnetic bars 620 and 621 out from (or nearly out from) the frame structure 610. In that configuration, the magnetic attraction from the magnets in the magnetic bars 620 and 621 secures the inductive heating module 600 to the external surface of the tank car, holding it in place for inductive heating. An example of inductive heating modules secured to the external surface of the tank car 200 is shown
Radially-curved pancake coils can be secured within the frame structure 610 in any suitable manner. In the embodiment shown in
While the inductive heating modules 500 and 600 are described as being secured (and removed) from a tank car using magnets, the inductive heating modules 500 and 600 can be secured using other mechanisms, such as clips, pins, bolts, welds, or other suitable means.
The mobile assembly and power source 800 can be embodied as a tractor-trailer that carries the equipment needed to install inductive heating modules, including the inductive heating modules, for example, onto the tank cars 710 and 720. The mobile assembly and power source 800 includes an electric generator 802, an inductive power supply 804, and wires or cables 806 to electrically couple alternating current from the inductive power supply 804 to the inductive heating modules 730-735 (among others). The mobile assembly and power source 800 further includes additional frame structures 810 and coil housings 820 for the assembly and installation of more inductive heating modules, for example, on the tank car 720. The crane 830 can be used, if necessary, to support the frame structures 810 against the tank car 720 while they are being secured to the tank car 720. Once the frame structures 810 are secured, the crane 830 can also be used to lift the coil housings 820 into the secured frame structures 810. Afterwards, the wires or cables 806 can be connected for inductive heating.
Although rail tank cars are shown in
Although embodiments have been described herein in detail, the descriptions are by way of example. The features of the embodiments described herein are representative and, in alternative embodiments, certain features and elements may be added or omitted. Additionally, modifications to aspects of the embodiments described herein may be made by those skilled in the art without departing from the spirit and scope of the present invention defined in the following claims, the scope of which are to be accorded the broadest interpretation so as to encompass modifications and equivalent structures.
This application claims the benefit of U.S. Provisional Application No. 62/188,744, filed Jul. 6, 2015, titled “Inductive Rail Tanker and Storage Tank Heating,” U.S. Provisional Application No. 62/251,765, filed Nov. 5, 2015, titled “Induction Heater for Portable and Stationary Tanks,” and U.S. Provisional Application No. 62/270,028, filed Dec. 20, 2015, titled “Portable Inductors for Stationary Marine Tanks and Other Uses (HYDRA+).”
Number | Name | Date | Kind |
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3809846 | Baumgartner | May 1974 | A |
20020195019 | Woodall | Dec 2002 | A1 |
20120048801 | Hong | Mar 2012 | A1 |
Number | Date | Country |
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2014280 | Jun 1994 | RU |
Entry |
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Machine Translation of RU2014280, published 1994; Translated Jan. 2019 (Year: 1994). |
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20170008537 A1 | Jan 2017 | US |
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62188744 | Jul 2015 | US | |
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62270028 | Dec 2015 | US |