Method for Modifying a Cargo Container for Delivery of Proppant to a Frac Site
A cargo container is modified to carry a fracing proppant such as sand from a quarry or source to the frac site. Openings are cut in the top and bottom of a cargo container and hydraulically operated sliding doors are placed there under. A hopper module with the walls being inclined to approximately the angle of repose for the proppant is installed inside the cargo container. The hopper module is sealed inside the cargo container so that a proppant enters through the top opening at the quarry and flows out through the bottom opening at the fracing site.
1 . A method of modifying a cargo container having cargo doors on one end thereof to transport a fracing proppant such as sand from one location to another, said method of modifying comprising the steps of:
cutting an upper opening and a lower opening in a top and bottom, respectively, of said cargo container;
inserting a hopper module through said cargo doors and anchoring said hopper module in said cargo container, said hopper module having hopper walls mounted on a frame with the angle of said hopper walls being approximately equal to an angle of repose for said proppant;
coating said hopper walls and part of inside walls of said cargo container with a slick material to aid in flow of said fracing proppant therein;
securing an upper hatch with an upper sliding door therein at said upper opening and a lower hatch with a lowering sliding door therein at said lower opening;
operating said upper sliding door and/or said lower sliding door to insert said proppant into said hopper module or to remove said proppant from said hopper module.
2 . The method of modifying a cargo container to transport said proppant therein as recited in claim 9 includes during said operating step wedging said upper sliding door and said lower sliding door against said upper opening and said lower opening, respectively, to prevent flow of proppant there through.
3 . The method of modifying a cargo container to transport said proppant therein as recited in claim 10 wherein during said operating step includes activating (a) an upper hydraulic cylinder to open/close said upper sliding door and (b) a lower hydraulic cylinder to open/close said lower sliding door.
4 . The method of modifying a cargo container to transport said proppant therein as recited in claim 11 further includes locating an upper control panel and a lower control panel in said cargo doors, said upper control panel controlling said upper sliding door and said lower control panel controlling said lower sliding door.
5 . The method of modifying a cargo container to transport said proppant therein as recited in claim 12 wherein said upper control panel and said lower control panel have both a manual and a remote way to operate said upper hydraulic cylinder or said lower hydraulic cylinder, respectively.
6 . The method of modifying a cargo container to transport said proppant therein as recited in claim 9 wherein said coating step includes spraying inside of said hopper module and said cargo container with a liner to aid flow of said proppant from said cargo container.
7 . A method for modifying a cargo container for delivery of proppant, said cargo container having a plurality of doors at one end thereof, said method comprising the steps of:
cutting a top opening into a top of said cargo container;
cutting a bottom opening into a bottom of said cargo container;
cutting a plurality of control panel openings into said plurality of doors of said cargo container;
constructing a hopper module;
inserting said hopper module within said cargo container;
securing a plurality of hatch assemblies within said cargo container; and
actuating said plurality of hatch assemblies from an opened position to a closed position or from said closed position to said opened position.
8 . The method of modifying a cargo container, as recited in claim 7 , wherein said constructing of said hopper module step further comprises:
forming a base having a quadrilateral configuration;
extending a front wall and a back wall from the top of said cargo container to the bottom center of said cargo container;
connecting side walls to said front wall and said back wall, said side walls extending from the sides of said cargo container to the bottom center of said cargo container;
connecting a plurality of braces between said front wall and said back wall and said base wherein each of said front, back and side walls is at an angle near the angle of repose of said proppant; and
welding cross support members to said front wall and said back wall, said welding step forming a plurality of weld spots uniformly spaced on the outside surfaces of said front and back walls; and
mounting said hopper module on said base.
9 . The method of modifying a cargo container, as recited in claim 8 , wherein in said securing step, each of said plurality of hatch assemblies comprising:
a top plate having an opening therein;
a flap attached at one end to said opening of said top plate and having the other end of said flap hanging in a vertical configuration relative to said top plate;
a trough having a wedge-shaped configuration with grooves and an opening therein, said trough connected to said top plate defining a volume therebetween and wherein said trough angles away from said top plate;
a sliding door having a wedge-shaped end and a shouldered end, said sliding door slidable along said grooves of said trough, said volume adapted to receive said sliding door; and
a cylinder connected to said sliding door at one end for extending and retracting said sliding door and connected to a hydraulic fluid source at the opposite end.
10 . The method of modifying a cargo container, as recited in claim 9 , wherein said actuating step further comprises using at least one control panel in fluid communication with said plurality of hatch assemblies, said control panel mounted within said plurality of control panel openings.
11 . The method of modifying a cargo container, as recited in claim 10 , wherein one of said plurality of hatch assemblies is in communication with said top opening of said cargo container.
12 . The method of modifying a cargo container, as recited in claim 11 , wherein one of said plurality of hatch assemblies is in communication with said bottom opening of said cargo container.
13 . The method of modifying a cargo container, as recited in claim 12 , wherein said top opening of said cargo container is in vertical alignment with said bottom opening of said cargo container.
14 . The method of modifying a cargo container, as recited in claim 13 , wherein when in said closed position, said wedge-shaped end of said sliding door is received by a corresponding wedge-shaped slot within said trough when said wedge-shaped end of said sliding door is inserted within said volume.
15 . The method of modifying a cargo container, as recited in claim 14 , wherein said flap is in a horizontal configuration when said sliding door is in a closed position.
16 . The method of modifying a cargo container, as recited in claim 15 , further comprising the step of coating the inside of said hopper module with a liner material.
17 . The method of modifying a cargo container, as recited in claim 16 , wherein said liner material is slick.
18 . The method of modifying a cargo container, as recited in claim 17 , wherein each of said plurality of hatch assemblies is controlled independently.
19 . The method of modifying a cargo container, as recited in claim 18 , wherein said sliding door of each of said plurality of hatch assemblies is actuated remotely.
20 . The method of modifying a cargo container, as recited in claim 19 , wherein said modified cargo container is stackable.