Unloading system and method for continuously moving rapid discharge railcars

An unloading station and method for unloading bulk material from a moving railcar with a bottom discharge while the railcar is moving includes a track with a pair of rails. A synchronized parallel conveyor is oriented parallel with the pair of rails and forms a movable platform capable of receiving the bulk material in a pile extending into the railcar and drawing the pile along in synchronization with the railcar as the railcar moves. A hopper is disposed below a break in or end of the parallel conveyor to receive the bulk material. A lateral conveyor disposed under the hopper to convey the bulk material away from the hopper.

PRIORITY CLAIM

Priority is claimed to U.S. Provisional Patent Application Ser. No. 61/072,182, filed Mar. 27, 2008, which is hereby incorporated herein by reference in its entirety.

BACKGROUND

1. Field of the Invention

The present invention relates generally to rapid discharge railroad cars, and more particularly to devices that unload rapid discharge railroad cars.

2. Related Art

Coal is often transported to processing or power plants by railroad cars. In the past, the plants have kept the railcars and unloaded the coal as needed. Unfortunately, such an unloading system utilized the railcars themselves for storage, so that the railcars are unavailable for use delivering coal. Therefore, coal processors have had to find other ways to unload coal trains and return the railcars to the railroad in shorter time periods, such as within eight hours for a 100 car train.

It has been suggested to unload the railcars by dumping the coal into a large pit, and then using conveyor belts to move the coal out of the pit. It will be appreciated, however, that the construction of a large pit required a large capital expense that is difficult to recover. In addition, construction of a large pit requires permits which can be difficult to obtain because they can interfere with underground water sources. Furthermore, deep pits can be difficult to maintain because they can interfere with the water table.

SUMMARY OF THE INVENTION

The inventor of the present invention has been recognized that it would be advantageous to develop a method and device for unloading aggregate material, such as coal, from a continuously moving railcar. Additionally, the inventor of the present invention has been recognized that it would be advantageous to develop a method and device that can receive an aggregate material from a moving railcar and move the aggregate material simultaneously with the moving railcar while removing or relocating the aggregate material away from the railcar. Furthermore, the inventor of the present invention has recognized that it would be advantageous to develop a method and device that can rapidly unload bulk material while requiring less capital expense.

The invention provides an unloading station for unloading bulk material from a moving railcar with a bottom discharge. The station includes a track having a pair of rails with the railcar movable on the track with the bulk material receivable around the pair of rails when the bottom discharge is opened. A synchronized parallel conveyor is oriented parallel with the pair of rails and forms a movable platform capable of receiving the bulk material in a pile extending into the railcar, and drawing the pile along in synchronization with the railcar as the railcar moves along the track to resist force from the pile against bottom discharge gates of the railcar. A break in or end of the parallel conveyor is disposed away from a proximal end of the parallel conveyor and is configured to allow the bulk material to pass therethrough. A hopper is disposed below the break in or end of the parallel conveyor configured to receive the bulk material. A lateral conveyor is disposed under the hopper and oriented transverse to the parallel conveyor configured to convey the bulk material away from the hopper.

In accordance with a more detailed aspect of the present invention, the station can include a frame positioned in a shallow excavation, less than 12 feet deep measured from a bottom of the pair of rails in line with existing rails from a railroad track.

In addition, the invention provides a method for unloading bulk material from a railcar with a bottom discharge including moving the railcar through an unloading station with a track having a pair of rails. The bottom discharge of the railcar is opened and the bulk material is released therefrom into a pile on a parallel conveyor while the railcar is moving. The parallel conveyor is moved with the pile of the bulk material thereon with the railcar. The bulk material on the parallel conveyor is allowed to fall into a hopper while the railcar is moving. The bulk material is laterally conveyed from the hopper and away from the unloading station with a lateral conveyor.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENT(S)

The present invention provides for an unloading station for continuously unloading aggregate or bulk material from a bulk material transport vehicle, such as a railcar with a bottom discharge, as the transport vehicle continuously moves along a pair of tracks or a roadway. The unloading station can include a track with a pair of rails disposed on a frame that can be placed in a shallow excavation (less than twelve feet). The rails can be aligned with existing rails of a fixed railroad track. A synchronized parallel conveyor, such as a chain belt, can be oriented parallel with the rails to receive the bulk material from the bottom discharge of the railcar and into a pile on the conveyor that moves with the railcar. A break in or end of the parallel conveyor can allow the bulk material to pass therethrough into a hopper. A lateral conveyor can be disposed under hopper to transport material to a remote location away from the unloading station.

In use, a belly dump railcar, such as a rapid discharge railcar, can be pulled onto the station and the contents of the railcar can be dumped while over the frame or rails such that a lower portion of the contents of the railcar fall and pile onto the synchronized parallel conveyor below while an upper portion remains in the railcar. The parallel conveyor can then move the pile along with the railcar simultaneously, or in sync with the railcar as the railcar moves along the pair of rails. The lower portion of dumped material can then be removed by the lateral conveyor while the dumped material and railcar simultaneously move along the rails. In this way, the upper portion of the dumped material remaining in the railcar exerts only minimal forces against the railcar and the discharge doors while the railcar is moving and the lower portion of the material is being removed. Thus, the railcar can be unloaded while still moving along the tracks.

As illustrated inFIGS. 1-11, an unloading station, indicated generally at10, is shown in accordance with an example of the present invention for use in unloading a continuously moving bulk material transport vehicle, such as a rapid discharge or bottom discharge railcar, indicated generally at14, while the railcar moves along a railroad track. Such an unloading station can be utilized for rapidly unloading coal from belly dump or rapid discharge railcars to coal processing plants or power plants. The unloading station10can include a track with a pair of rails18which can be placed in-line with the railroad track to receive railcars.

The track and pair of rails18can be carried by and supported by a frame22. The frame22can extend in a direction that is in-line with the railroad tracks. The frame can be sized and shaped to support and carry the track and pair of rails18over the shallow excavation. For example, the frame22can include a pair of I-beams26extending longitudinally along the frame and substantially parallel to the railroad tracks. Each I-beam26can be sized and shaped to support and carry one of the rails18. The pair of rails18can be alignable with existing rails of the railroad track so as to provide a continuous pathway for railcars14traveling on the railroad track and onto the unloading station10. The frame, or sections thereof, can have a length of approximately 50 feet. In one aspect, the frame can have an overall length of approximately 100 feet, formed by two sections of approximately 50 feet each. In addition, the frame can have a width of approximately 16.5 feet. Therefore, the frame, or sections thereof, can be manufactured remotely or off-site, and transported on highways in accordance with Department of Transportation regulations. The frame can also include sidewalls30on opposite lateral sides parallel with the track and pair of rails18. The sidewalls can extend higher than the rails. The sidewalls and I-beams can be coupled together with cross-members.

The frame22with the track and the pair of rails18can be positioned in a shallow excavation34. In accordance with one aspect of the present invention, the excavation can have a depth less than 12 feet (measured from the bottom of the track or pair of rails). In accordance with another aspect of the present invention, the excavation can have a depth less than 10 feet. It will be appreciated that the shallow excavation provides an advantage in that less capital expenses is involved in installing the unloading station, and water table issues can be avoided. In one aspect, a portion of the frame can be above a ground level and the remaining portion of the frame can be below ground. The excavation can include footings or retaining walls or the like upon which the frame is supported. All or a portion of the frame can be elevated above a bottom of the excavation to receive a hopper and a lateral conveyor as discussed in greater detail below.

A synchronized parallel conveyor, indicated generally at40, can be carried by the frame22and oriented parallel with the track and the pair of rails18. The parallel conveyor can include one or more conveyors disposed between and on opposite sides of the pair of rails. The parallel conveyor(s) can include two conveyors between the rails, and two conveyors on each side of the rails. Thus, the parallel conveyor(s) can have a width greater than five feet in one aspect, and can have a width of approximately 14 feet in another aspect. The parallel conveyor can extend substantially the entire length of the frame, approximately 90 feet, from a proximate end around a proximate sprocket(s)44which first encounters the railcar to a distal end around a drive sprocket(s)48where the railcar exits the station. The drive sprocket(s) can be coupled to a motor52, such as an electric motor or hydraulic motor. The parallel conveyor40can include one or more continuous chains56looped around the sprockets44and48. The chain(s)56can include opposite lateral links60coupled by pins64, as shown inFIG. 9. The pin spacing can be approximately 8 inches and the pin length, or chain width, can be approximately 1 foot, 9 inches, creating an opening68of approximately 94 square inches. It will be appreciated that teeth on the drive sprocket can engage the openings and pins of the chain to move the chain.

In addition, the parallel conveyor40can include one or more stationary decks, such as preliminary and subsequent stationary decks72and76, respectively. The stationary decks can include a top layer80of low friction material supported by a lower layer84of structural material, such as metal or steel, as shown inFIG. 8b. The stationary decks can be supported on the frame by the I-beams, side walls, and/or cross-members. The chain56can be pulled across the stationary decks or low friction material thereof. The parallel conveyor or continuous chain movable across the decks can form a movable platform capable of receiving bulk material88. The movable platform can have a preliminary portion defined by the preliminary stationary deck, and a subsequent portion defined by the subsequent stationary deck. In use, the station10receives a plurality of moving railcars14with bottom discharge along the track and the pair of rails18. While in motion, the bottom discharge of the railcar14on the station10is opened and the bulk material88is received around the pair of rails and into a pile(s) on the parallel conveyor40. It will be appreciated that only an initial portion of the bulk material is received onto the parallel conveyor, while a remaining portion of the bulk material remains in the railcar. Thus, the pile extends into the railcar. The parallel conveyor40draws the pile along synchronized with the movement of the railcar along the track, as shown inFIGS. 5aand5b. The motor52can drive the conveyor so that it is synchronized with the railcar. It will be appreciated that gates of the bottom discharge hang down from the railcar about the pile of bulk material. Moving the pile of the bulk material along with the railcar resists the gates from plowing through the bulk material causing stress on the gates and/or derailment of the railcar.

One or more openings can be formed in the parallel conveyor, movable platform or stationary decks. For example, a preliminary break92can be disposed between the preliminary and stationary decks72and76. As the chain56moves across the break92, the bulk material88can fall or pass through the openings68(FIG. 9) in the chain and through the movable platform or stationary decks. It will be appreciated that the openings in the chain also grade the material. It will also be appreciated that the bulk material passes through the chain twice, once on the top, and again as the chain returns on the bottom. The preliminary break92can be disposed away from the proximal end of the parallel conveyor, such as more than 50 feet from the proximal end. Thus, an entire railcar can be received on the parallel conveyor prior to the preliminary break92. In addition, a subsequent break96can be disposed near the distal end of the parallel conveyor. As another example, a subsequent end100of the parallel conveyor can be open. Thus, a preliminary portion of the bulk material can be received on the preliminary deck, and can pass through the preliminary break; while a subsequent or remaining portion of the bulk material can be received on the subsequent deck, and can pass through the subsequent break or fall off the subsequent end of the conveyor. A distance at the end of the parallel conveyor between the parallel conveyor and hopper can be greater than the openings in the chain to allow larger pieces of bulk material into the hopper.

In another aspect, the parallel conveyor can include one or more conveyor belts. The conveyor belts can extend parallel to the pair of rails and can move about a head pulley and a tail pulley in the direction of the travel of the railcar on the pair of rails. The conveyor belts can engage a lower portion of bulk material discharged from a railcar and move the bulk material parallel to the pair of rails to a discharge end of the conveyor system.

In yet another aspect, the parallel conveyor can include one or more chains or belts in series or tandem with the opening or break therebetween. Thus, the preliminary portion of the movable platform can be defined by one or more continuous chains movable over the preliminary stationary deck by one motor; and the subsequent portion of the movable platform can be defined by one or more separate continuous chains movable over the subsequent stationary deck by another motor.

One or more hoppers, such as preliminary and subsequent hoppers104and108respectively, can be disposed bellow the preliminary and subsequent breaks92and96, and subsequent end100. The hoppers can include walls to contain the bulk material. The walls can be inclined to funnel the bulk material. The hoppers can have an inlet opening with a width as wide as the parallel conveyor, and a length of approximately 11 feet. The hoppers can have an outlet opening that is smaller.

One or more lateral conveyors, such as preliminary and subsequent lateral conveyors112and116, respectively, can be associated with the hoppers104and108. For example, a beginning end of the lateral conveyors can be disposed under the hoppers. The lateral conveyors112and116can be oriented transverse, i.e. angled with respect to, the parallel conveyor. In addition, the beginning end of the lateral conveyors can be disposed in the excavation34, and inclined with respect to the ground. It will be appreciated that the size of the lateral conveyors, width of the hoppers or outlet openings thereof, and inclination of the lateral conveyors contribute to the depth of the excavation below the frame and parallel conveyor. The lateral conveyors convey the bulk material out of and away from the hoppers. It will be appreciated that another conveyor system (not shown) can receive the bulk material from the lateral conveyors. The hoppers can extend from the decks or platform to the lateral conveyors to reduce coal dust from escaping.

The two lateral conveyors, and preliminary and subsequent breaks with their associated preliminary and subsequent decks, allow the railcar to be unloaded in two stages. Unloading the railcar in two stages allows the bulk material to be unloaded more continuously or constantly; which can be desirable if the coal is being processed.

In addition, having two removal points facilitates continuous movement of the railcars, as shown inFIG. 11. For example, when a first car passes the first discharge end and removal point and moves to the second chain belt, a second railcar can dump its material onto the first chain belt and together the two railcars can continue to move along the rails while the material transfer device simultaneously moves the dumped material along the rails in sync with the moving railcars. Thus, when the first railcar passes the second discharge end and is empty, the second car passes to the second chain belt and is partially empty, and a third car enters the unloading station and dumps its material onto the first chain belt. In this way, a very long train of railcars can be unloaded while the railcars are continuously moving.

Although two lateral conveyors have been shown and described, it will be appreciated that the station can be provided with a single lateral conveyor associated with a single break or end in the parallel conveyor and a single hopper. Alternatively, three or more lateral conveyors with associated breaks or ends and hoppers can be provided. In addition, although the lateral conveyors are shown extending from the same side of the station, it will be appreciated that they can extend from different sides of the station.

Furthermore, any number of unloading stations can be coupled together in series in order to unload the railcars of a multiple railcar train in a relatively quick and efficient manner. In this way, the unloading station of the present invention can be configured to unload a predetermined number of railcars in a predetermined amount of time. For example, the station can be configured to unload 100 railcars in an eight hour period, as currently required by some rail carriers.

As described above, the frame can be formed in two sections. The second section can include the openings, or break(s) and end. Thus, the excavation can be deeper (less than 12 feet, or less than 10 feet) for the second section, and shallower for the first section. In addition, the excavation can be wider for at the second section to accommodate the lateral conveyors. In addition, the frame can be separate from the hoppers and lateral conveyors. Thus, the configuration of the lateral conveyors with respect to the frame can be more easily reconfigured. Furthermore, the shallow excavation and transportability of the frame allow the station to be more easily repositioned.

The station can further include a lift120disposed between the frame and the excavation, as shown inFIG. 2b. The lift can include one or more hydraulic cylinders. Thus, the frame can be lifted with respect to the hoppers and lateral conveyors for service.

The present invention also provides a method for using the unloading station described above or a method for unloading bulk material88from a railcar14with a bottom discharge. The railcar14is moved through an unloading station14with a track having a pair of rails18. The bottom discharge of the railcar is opened, releasing the bulk material88from the railcar and into a pile on a parallel conveyor40while the railcar is moving. The parallel conveyor is moved with the pile of the bulk material thereon with the railcar. The movement of the parallel conveyor and the railcar can be synchronized so that they move together at substantially the same speed. Synchronization can be accomplished in numerous ways. For example, an operator of the unloading station can manually control the speed of the locomotive pulling the railcar with a wireless remote control so the speed of the locomotive and railcar match the speed of the parallel conveyor. As another example, an operator of the unloading station can manually control the speed of the motor52driving the parallel conveyor so that the speed of the parallel conveyor matches the speed of the railcar. As another example, sensors can be associated with the unloading station to sense or measure the speed of the railcar and automatically adjust the motor52via a controller.

The bulk material88in a pile on the parallel conveyor extends into the railcar, and is moved along with the railcar as the railcar moves by the parallel conveyor. The bulk material88can pass through the openings68(FIG. 9) in the continuous chain56and onto the stationary deck72. The continuous chain56pulls the bulk material along the stationary deck72. The bulk material88on the parallel conveyor and stationary deck is allowed fall into a hopper104while the railcar is moving. The continuous chain56pulls the bulk material over an opening or break92in the moving platform, such as an end of the preliminary stationary deck72. The bulk material is laterally conveyed from the hopper104and away from the unloading station by a lateral conveyor112.

The bulk material88can be unloaded entirely on the preliminary deck72and allowed to pass through the preliminary break92into the preliminary hopper104. It will be appreciated that the preliminary break92can be the end of the continuous chain which can terminate in the vicinity of the preliminary hopper, i.e. somewhere above the hopper. Alternatively, the bulk material can be unloaded in stages, with an initial amount of the bulk material received onto the preliminary deck and through the preliminary break into the preliminary hopper. A remaining portion of the bulk material can be released from the railcar and onto a subsequent portion of the parallel conveyor beyond the preliminary hopper while the railcar is moving. The subsequent portion of the parallel conveyor can be a subsequent portion of the parallel conveyor, or a separate subsequent parallel conveyor separate from a preliminary parallel conveyor. For example, the remaining portion of the bulk material can be released onto a subsequent stationary deck76and moved along by the continuous chain56. Thus, the subsequent portion of the parallel conveyor moves the remaining portion of the bulk material thereon with the railcar. The remaining portion of the bulk material on the subsequent portion of the parallel conveyor is allowed to fall into a subsequent hopper108while the railcar is moving. The remaining portion of the bulk material can pass through a subsequent opening or break96in the stationary deck76or moving platform, and/or subsequent end100of the parallel conveyor. The remaining portion of the bulk material is laterally conveyed from the subsequent hopper and away from the unloading station while the railcar is moving by a subsequent lateral conveyor116. Again, it will be appreciated that any number of intermediate portions of the bulk material can pass through intermediate openings into intermediate hoppers.

The method can further include installing the unloading station10by causing an excavation34to be excavated less than 10-12 feet deep (measured from a bottom of the pair of rails in line with rails from a railroad track). The track with the pair of rails18can be formed on a frame22to carry the track. In addition, the stationary decks72and76, I-beams26, sidewalls30and/or cross-members can be formed on the frame. As described above, the frame can be formed in segments or portions, such as two portions as shown. The frame with the track is transported to the excavation. A proximal end of the lateral conveyor(s)112and116can be disposed in the excavation. The hopper(s)104and108can be disposed over the proximal end of the lateral conveyor(s) in the excavation. The frame with the track can be placed in the excavation, such as with a crane. The continuous chain56can by placed around the decks.

The method can further include raising the frame22with the track and the parallel conveyor with respect to the excavation34containing the frame and with respect to the lateral conveyor(s) with the lift120.