The invention relates generally to the field of liquid pressurization systems and processes. More specifically, the invention relates to methods and apparatuses for restoring and cleaning rails using pressurized liquid jets.
Liquid pressurization systems produce high pressure (e.g., 20,000 to 90,000 pounds per square inch (PSI)) streams of liquid for various applications. For example, high pressure liquid may be delivered to a liquid jet cutting head, a cleaning tool, a pressure vessel or an isostatic press. In the case of liquid jet cutting systems, liquid is forced through a small orifice at high velocity to concentrate a large amount of energy on a small area. To cut hard materials, a liquid jet can be “abrasive” or include abrasive particles for increasing cutting ability. As used herein, the term “liquid jet” includes any substantially pure water jet, liquid jet, and/or slurry jet. However, one of ordinary skill in the art would easily appreciate that the invention can apply to other systems that use liquid pumps or similar technology.
Railways are an important mode of transportation throughout the world. However, prolonged usage and heavy loads can cause rails to deform and wear over time. Damaged rails create bumpy rides, stresses on train car wheels contacting the rails, and other damage, and replacing damaged railroad tracks can be very expensive. One known method to repair railroad tracks is to use large grinding trains to machine the tracks, but this method is loud, unpleasant and expensive, particularly when applied to damaged areas. The sound and resulting sparks are so offensive that these trains are often referred to as “hell trains.” Moreover, this grinding technique is not effective around corners or at junctions. What is needed is an improved method to treat (e.g., repair, reshape and restore) existing railroad tracks.
The present invention includes a new mobile liquid jet system that uses one or more pressurized liquid streams to treat damaged, worn or dirty railway rails. The system can include a mobile platform (e.g., a truck, a train, a rail car or cars, or other rail-going systems) that supports a waterjet system capable of operating on the move (e.g., as it travels down the very tracks it is treating) while machining the rails via one or more pressurized liquid jets. The system can include a robot or other motion system, which can be placed over or adjacent to the rail being serviced, but does not necessarily have to be attached to the serviced rail. In some embodiments the invention may include a portable truck mounted unit (see, e.g.,
In one aspect, the invention features a translatable, ultra-high pressure liquid jet system. The liquid jet system includes a translatable frame configured to maintain mechanical contact with a rail. The liquid jet system also includes a liquid jet processing head affixed to the frame and configured to maintain a distance from the rail and/or provide a liquid jet that contacts the rail. The liquid jet system also includes an ultra-high pressure liquid pump in fluid communication with the liquid jet processing head. The ultra-high pressure liquid pump is configured to supply pressurized liquid to the liquid jet processing head.
In some embodiments, the frame is attached to one or more wheels configured to contact the rail. In some embodiments, the system is configured to translate along the rail via the one or more wheels during a rail processing operation. In some embodiments, the ultra-high pressure liquid pump is disposed on the frame. In some embodiments, the ultra-high pressure liquid pump is disposed on a unit separate from the frame and is capable of moving independently of, and at a different speed than, the frame. In some embodiments, the system is configured to remove an exterior portion of the rail having a linear dimension between 0.01 mm and 0.1 mm. In some embodiments, the system is configured to remove an exterior portion of the rail having a linear dimension between 0.1 mm and 1.0 mm. In some embodiments, the system is configured to remove an exterior portion of the rail having a linear dimension between 1.0 mm and 5.0 mm.
In some embodiments, the liquid jet processing head is configured to provide the liquid jet to the rail at an angle relative to a ground plane. In some embodiments, the system further includes second and third liquid jet processing heads in fluid communication with the ultra-high pressure liquid pump and configured to provide second and third liquid jets, respectively, to the rail at second and third angles, respectively, relative to the ground plane. In some embodiments, the system further includes fourth, fifth and sixth liquid jet processing heads in fluid communication with the ultra-high pressure liquid pump and configured to provide fourth, fifth and sixth liquid jets, respectively, to a second rail opposite the first rail at fourth, fifth and sixth angles, respectively, relative to the ground plane.
In some embodiments, the liquid jet processing head is affixed to a positioning system attached to the frame. The positioning system is configured to adjustably position the liquid jet processing head with respect to the rail. In some embodiments, the positioning system includes at least one of a gantry or a robotic arm attached to the frame and is moveable independently of the frame. In some embodiments, a second frame is configured to engage the rail. The second frame is moveable relative to the frame during operation of the ultra-high pressure liquid jet system. In some embodiments, the second frame includes a liquid reservoir fluidly connected to the ultra-high pressure liquid pump. In some embodiments, the liquid reservoir has a capacity of at least 1,000 liters.
In some embodiments, a generator is disposed on the second frame and operably connected to the ultra-high pressure liquid pump. In some embodiments, the liquid jet processing head is configured to process the rail while the second frame translates along the rail. In some embodiments, the system includes a nozzle fluidly connected to the liquid jet processing head. In some embodiments, the liquid jet system includes an abrasive feed system fluidly connected to the liquid jet processing head and configured to introduce a flow of abrasive into the liquid jet. In some embodiments, the ultra-high pressure liquid pump is configured to generate a liquid jet of at least 20,000 PSI for a rail cutting operation or a re-profiling operation, or optionally a higher threshold, e.g., 30,000 PSI, 40,000 PSI, 50,000 PSI, 60,000 PSI, 70,000 PSI, 80,000 PSI, 90,000 PSI, or 100,000 PSI. In some embodiments, the ultra-high pressure liquid pump is configured to generate a liquid jet of between 200 to 2,000 PSI for a rail cleaning operation or a surface treatment operation (e.g., is also capable of a low-pressure application).
In another aspect, the invention features a method of operating an ultra-high pressure liquid jet system. The method includes positioning, relative to a rail, a translatable frame having a liquid jet processing head fluidly connected to an ultra-high pressure liquid pump. The method also includes providing, to the liquid jet processing head, via the ultra-high pressure liquid pump, a pressurized fluid forming a liquid jet that contacts the rail. The method also includes translating the liquid jet processing head relative to the rail, thereby performing a processing operation on a linear length of the rail along a direction of translation of the rail.
In some embodiments, the frame includes one or more wheels configured to engage the rail. In some embodiments, a movement of the ultra-high pressure liquid pump corresponds to translation of the frame. In some embodiments, the ultra-high pressure liquid pump is fixedly connected to the frame. In some embodiments, the ultra-high pressure liquid pump is disposed on a unit separate from the frame and is capable of moving at a different speed than the frame. In some embodiments, the liquid jet processing head is configured to provide the liquid jet to the rail at an angle relative to a ground plane. In some embodiments, the pressurized fluid is at least 20,000 PSI during a rail cutting operation or a re-profiling operation, or optionally a higher threshold, e.g., 30,000 PSI, 40,000 PSI, 50,000 PSI, 60,000 PSI, 70,000 PSI, 80,000 PSI, 90,000 PSI, or 100,000 PSI. In some embodiments, the pressurized fluid is between 200 to 2,000 PSI during a rail cleaning operation or a surface treatment operation. In some embodiments, the ultra-high pressure liquid pump is included in a second frame moveable independently of the first frame during operation of the liquid jet system. In some embodiments, the method further includes translating the second frame at a different speed than the frame during operation of the liquid jet system.
In some embodiments, the liquid jet processing head is configured to provide the liquid jet to the rail at an angle relative to a ground plane. In some embodiments, the frame further includes second and third liquid jet processing heads fluidly connected to the ultra-high pressure liquid pump. In some embodiments, the method further includes providing, to the second and third liquid jet processing heads, via the ultra-high pressure liquid pump, pressurized fluid forming second and third liquid jets, respectively, that contact the rail at second and third angles, respectively, relative to the ground plane. In some embodiments, the ultra-high pressure liquid jet system includes fourth, fifth and sixth liquid jet processing heads in fluid communication with the ultra-high pressure liquid pump. In some embodiments, the method further includes providing, to the fourth, fifth and sixth liquid jet processing heads, via the ultra-high pressure liquid pump, pressurized fluid forming fourth, fifth and sixth liquid jets, respectively, that contact the rail at fourth, fifth and sixth angles, respectively, relative to the ground plane.
In another aspect, the invention features a curved jet nozzle for an ultra-high pressure liquid jet system. The curved jet nozzle includes a frame configured to engage a rail. The curved jet nozzle also includes at least two liquid jet processing heads attached to the frame at different angles with respect to a ground plane. The curved jet nozzle also includes an ultra-high pressure liquid pump fluidly connected to the at least two liquid jet processing heads and configured to provide pressurized fluid to each of the at least two liquid jet processing heads to form one liquid jet that contacts the rail. In some embodiments, the at least two liquid jet processing heads are positioned to provide liquid jets that intersect each other at an acute angle to create a stream with a different trajectory that creates a smooth finish on the rail during a processing operation free of burl that remains after an initial cutting operation.
In another aspect, the invention features another method of operating an ultra-high pressure liquid jet system. The method includes positioning, on two rails spaced at a distance from each other, a translatable frame having (i) a set of wheels for contacting the two rails, and (ii) two sets of three liquid jet processing heads fluidly connected to an ultra-high pressure liquid pump, each set of three liquid jet processing heads aimed at one of the two rails. The method also includes providing, to the two sets of three liquid jet processing heads, from the ultra-high pressure liquid pump, pressurized fluid forming two sets of three liquid jets that contact the two rails. The method also includes translating the frame relative to the rails, thereby performing a processing operation on a linear length of the rails along a direction of translation.
In another aspect, the invention features a translatable, ultra-high pressure liquid jet system. The system includes first means for maintaining mechanical contact with a rail. The system also includes second means for providing a liquid jet that contacts the rail, the second means attached to the first means and configured to maintain a distance from the rail. The system also includes third means for supplying pressurized liquid to the second means, the third means in fluid communication with the second means.
In some embodiments, the invention is capable of re-profiling a rail (e.g., repairing or re-surfacing a damaged rail area or volume), removing the need for maintenance and removing only a small width (e.g., about 0.03 mm) of rail material in the process. In some embodiments, a “curved jet” abrasive waterjet nozzle can fan the liquid jet and/or reorient the waterjet in a curved manner. Such a curved jet nozzle can be formed by intersecting two linear or curvilinear water jets at an acute angle such that a merged stream is formed and flows with a changed trajectory before encountering a rail, or can be curved via another means. In some embodiments, the invention uses two connected mobile units that may have different speeds relative to one another (e.g., they may have different or intermittent movement, with one carrying the cutting head and another carrying the liquid reservoir). In some embodiments, motion of the cutting head can have multiple components (e.g., movement of the system itself along the rail and movement of the gantry or arm relative to the system). In some embodiments, a waterjet cutting head positioning mechanism can slide along one or more rails being treated. In some embodiments, the surface of the rails can be surface-treated with a liquid jet (e.g., a lower pressure water jet of less than about 20,000 PSI, e.g., 200-2,000 PSI).
Using one or more of the above distinctive features, the entire liquid jet system (e.g., including the pump, fluid supply, cutting head, etc.) can function while moving and process (e.g., repair and perform preventative maintenance on) one or more rails. The invention can thus provide a quick, inexpensive and clean way to recondition old or damaged rails, and to perform preventative maintenance on existing rails. The invention can perform processing most anytime and anywhere, including around corners and through junctions. In some embodiments, the invention is highly flexible from a logistical perspective, particularly as compared to hell trains, which can be very difficult and time consuming to move. In some embodiments, the invention provides negligible heat input into the rails (e.g., the rail temperature does not exceed 90° C., which has no appreciable influence on the rail), and this can increase the overall lifetime of the product and the rails.
In some embodiments, the invention is environmentally friendly, e.g., is capable of using recycled water, sand and metal. In some embodiments, the invention produces low noise levels as compared to existing technologies. In some embodiments, the invention does not produce any sparks, which can make the invention uniquely suited to resurfacing rails in certain higher risk environments, e.g., near chemical plants, in tunnels, and above water ways. In some embodiments, the invention produces high accuracy results, which causes less rework or fewer adjustments to need to be performed. In some embodiments, the invention provides a high quality surface finish, e.g., using a burl removal tool, which can operate on the rail after the main cutting operation is performed, and/or can include one or more “curved” jets (or “curved jet nozzles”) as described herein.
In some embodiments, the invention supports at least two types of treatment: surface and re-profiling. Surface treatment can involve removing a chemical layer only (e.g., not steel or rail material), and for such applications no abrasive is typically used. Re-profiling can involve removing a surface layer of track, and for such applications an abrasive is typically used. In some applications, only 0.1-0.2 mm of rail is removed. In other applications, the invention can remove 1.0-2.0 mm of rail. Such treatments can help the rails endure for another 5-10 years of normal use before requiring further repair or replacement. In some embodiments, the cutting heads can be positioned anywhere between 0.1 mm to 60 mm away from the rail (e.g., 0.1 mm, 0.125″, 0.5″, or 1.5″) for cutting applications. In some other embodiments, the cutting heads can be positioned anywhere between 20-50 cm away from the rail for spraying applications. In some embodiments, a polishing machine can be applied to the rails behind the cutting heads (e.g., using sandpaper) without imparting any substantial heat into the track. In some embodiments, only the inside edge of each rail is processed, as the outside edge does not contact the wheel of the rail-mounted train and thus does not need to be treated. In some embodiments, a diameter of the nozzle (e.g., orifice size) can be selected based upon the operation to be performed. For example, an orifice size of about 0.010″-0.045″ can be used, optionally 0.010-0.025″, optionally 0.010-0.016. In some embodiments, a mixing tube having a diameter of about two to three times as large as the orifice can be used.
The foregoing discussion will be understood more readily from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
The waterjet system 116 includes at least one cutting head (e.g., as shown and described below) to process the rail 124. The cutting head may be connected to the pump of the waterjet system 116 via flexible tubing or hosing to account for movement in the system. In some embodiments, the waterjet system 116 can include multiple (e.g., six) cutting heads. The waterjet system 116 can also include a gantry, robot arm, or other positioning mechanism to orient the waterjet cutting head relative to the rail 124 being repaired (e.g., as shown and described below). The waterjet system 116 can also include a CNC controller, such as an Edge® Connect system offered by Hypertherm, Inc., to position the cutting head and/or control its processing parameters. Thus, the invention can include a platform housing the generator, the waterjet pump and/or intensifier, the cutting head, the cutting liquid, the abrasive, and the controller, all fully operational while moving.
The MCU 100 includes a rail engagement motion system 120, which can engage and maintain mechanical contact with the rails 124. Before operation, the truck 104 can drive as it would normally (e.g., as shown in
The current invention can provide improved positioning and movement of a traditional liquid jet cutting head. Typical cutting heads are movable on a fixed grid (e.g., in an x-y direction), but in the present invention, an angular adjustment mechanism can be provided to move the angle of the liquid jet relative to the rail. Such a mechanism can have distinct advantages in the context of the invention because of the unique angles and proximity to the ground that can be desirable. For example, in a typical liquid jet cutting setup, it is immaterial how wide the cutting head is, but in the current context, there are tighter geometrical constraints. For example, the cutting head needs to be positioned high enough off the ground so that it does not encounter debris on the ground, such as stones, or bolts that ascend upward from the base of the tracks—but low enough to actually contact the rails, and adjustable to contact the rails at the desired angle. The available space for cutting heads becomes particularly tight in setups involving multiple cutting heads, especially if they are positioned low to the ground. For such cases, the invention can include a narrower, thinner cutting head.
The liquid jet itself is typically circular, as it emerges from the nozzle of the waterjet cutting head and has a diameter that is controlled by the orifice and/or mixing tube of the liquid jet cutting head. The diameter of the liquid jet as it emerges from the nozzle tip is in the range of about 0.005 inches to about 0.120 inches; and is optionally in the range of about 0.0075 inches to about 0.045 inches; and is optionally in the range of between about 0.010 inches and 0.025 inches. In some embodiments, the preferred range is between about 0.010 inches and 0.016 inches. Typically the mixing tube is about three times as large as the orifice, although in some embodiments it can be about 2 times as large. The diameter of the liquid jet stream can be adjusted and/or selected based upon the chosen process. The cross-sectional area of the liquid jet stream at the impact and/or focus point on the rail is typically in the range of about 0.00002 in2 to about 0.06 in2; and can be in the range from about 0.00004 in2 to about 0.0016 in2; and can be in the range from about 0.00008 in2 and 0.0005 in2. In some embodiments, the range is preferably between about 0.00008 in2 and 0.0002 in2.
These configurations are exemplary and demonstrate the wide variety of cutting and grinding operations made possible by the current invention. In some embodiments, the invention can be used for re-profiling and/or conditioning. For example, in a re-profiling operation, multiple nozzles may be positioned lengthwise, perpendicular to the rail, or at another angle to the rail. In some embodiments, to remove material, the nozzles are positioned close to the rail (e.g., so the stream velocity is high and not as impacted by dissipative forces such as air resistance). In some embodiments, in a finishing operation, the nozzles are positioned further away from the rail. In some embodiments, the angle of impingement can depend on the force needed at impact, which can in turn depend on the operation to be achieved (e.g., heavy damage may warrant a different angle than lighter damage). In a conditioning operation, to remove an undesirable layer off the rail, one or more nozzles can be positioned lengthwise with respect to the rail, e.g., as in
While the invention has been particularly shown and described with reference to specific preferred embodiments, it should be understood by those skilled in the art that various changes in from and detail may be made therein without departing from the spirit and scope of the invention as defined by the following claims.
This application is a non-provisional of U.S. Provisional Patent Application No. 62/732,175, filed on Sep. 17, 2018 and entitled “Mobile Waterjet Rail Repair System.” The contents of this application are incorporated herein by reference in their entirety.
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