US 20050189358 A2
Abstract of the Disclosure
A tank for transporting liquids is provided. The tank includes a tank vessel having an internal baffle system including an X-shaped baffle arrangement that extends through the interior of the tank vessel in the longitudinal direction. A plurality of entry hatches can be provided in the tank vessel for permitting access into the interior of the tank vessel. Each entry hatch has a removable hatch plate and is sized to allow a person to enter the tank therethrough. At least selected ones of the baffles in the tank have access openings therethrough. Each access opening has an associated pivotal baffle door that is movable between open and closed positions. The access openings are provided in the baffles such that a person can traverse through the interior of the tank between two of the entry hatches. The tank also is equipped with a variable volume system.
19. A tank for transporting liquids having an interior space; a plurality of baffles in the interior forming compartments; one or more doors in the plurality of baffles sized to allow personnel to walk between compartments, at least two openings in any one or more exterior surfaces of the tank allowing the personnel to enter the interior at one of the openings on the exterior surfaces, walk through the one or more doors and exit the interior at another of the openings in the exterior surfaces.
20. The tank of
21. The tank of
22. The tank of
23. The tank of
24. The tank of
25. The tank of
26. The tank of
27. A tank for transporting liquid comprising an interior having a baffle network spanning the top and the floor so as to provide structural support for an exterior surface of the tank; and, a door in at least one of the baffles allowing humans to move between chambers of the tank defined by the baffle network when opened and substantially isolating the liquid in each chamber from liquid in others when closed.
28. The tank of
29. The tank of
30. The tank of
31. The method according to
32. The tank of
33. The tank of
34. A tank for transporting liquids comprising a plurality of baffles defining compartments in a interior of the tank; at least some of the compartments having personnel access openings in the baffles allowing personnel ingress and egress into and from the compartments by moving through the openings; at least one of the access openings including a door pivotable between open and closed positions to substantially inhibit the flow of the liquid through the access opening in the closed position.
35. The tank of
36. The tank of
37. A tank for transporting liquids comprising a plurality of baffles in an interior space defining compartments; a personnel access opening in at least one of the plurality of baffles sized to allow humans to walk through the opening; and the personnel access opening having a door supported by a surface of the tank to allow the door to move between open and closed positions.
38. The tank of
39. The tank according to
40. The tank according to
41. The tank according to
42. The tank of
43. A tank for holding fluids comprising a closed interior accessible through a opening in the top of the tank for filling the tank with the fluids; a fill tube extending from the opening into the closed interior; at least one valve for releasing air from the interior at a point above a lower edge of the fill tube; and the at least one valve operable for selecting a maximum fluid fill line in the interior either at the lower edge of the fill tube or at a higher level at which the at least one valve releases air from the interior of the tank.
44. The tank of
45. The tank of
46. The tank of
47. A method for making an opening in a baffle of a tank for transporting liquids, where the baffle separates the tank into chambers that prevent substantial flow of the liquid between the chambers, the method comprising:
cutting an opening in the baffle large enough for a human to walk through;
creating a door from material removed from the baffle or another baffle to create the opening; and
hanging the door on the baffle to operate between open and closed positions, where the closed position substantially prevents flow of the liquid between the chambers and the open position allows ingress and egress by a human between the chambers.
48. The method of
49. A tank for transporting fluid comprising:
a pump for discharging fluid from the tank driven by a hydraulic motor;
a supply line for directing hydraulic fluid to an inlet of the hydraulic motor;
a return line for directing hydraulic fluid from an outlet of the hydraulic motor to a hydraulic fluid storage tank; and
a hydraulic valve in a fluid line for bypassing the hydraulic motor and extending between the supply line and the return line, the hydraulic valve operable during a start-up of the hydraulic motor to allow some fluid to bypass the hydraulic motor through the bypass line until the hydraulic motor substantially reaches normal operating speed.
50. The tank of 49 wherein the hydraulic valve comprises a pressure relief valve.
51. The tank of
52. The tank of
53. A tank for transporting fluids comprising a plurality of baffles defining compartments in an interior; an agitation system for agitating fluid in the tank including (1) a draw tube having an opening in communication with the interior of the tank, (2) an agitation tube having a plurality of outlets in communication with the interior of the tank, and (3) a pump drawing fluid from the interior and supplying pressurized fluid to the agitation tube for discharging into the tank and agitating the contents of the tank.
54. The tank of
55. The tank of
56. A method for making a door for a baffle of a tank comprising cutting an opening in the baffle; creating a door to match the opening, where the door includes parts shaped to function as hinges when mated to the baffle in a manner allowing the door to operate between open and closed positions.
57. The method of
58. The method according to
59. A method for making a tank baffle comprising cutting an opening in the baffle, with the opening being associated with a plurality of slots for receiving tabs integral with a door for mating with the opening such that the mated tabs and slots form hinges enabling the door to operate between open and closed positions such that the open position allows humans to ingress and egress chambers of the tank defined by the baffle and the closed position substantially isolates fluid in each of the chambers.
60. The method according to
61. A plurality of lifting eyes disposed on the upper surface of a tank to facilitate installation and removal of the tank from a tanker truck chassis, each lifting eye comprising a body and a reinforcing plate, the body includes a keyed lower portion and an upper portion having an eye formed therein, the reinforcing plate including an opening for receiving the upper portion of the body such that the keyed lower portion of the body, which is larger than the opening in the reinforcing plate, abuts against the lower surface of the reinforcing plate, the upper portion of the body extending through an opening in a top wall of the tank such that the eye is positioned above the upper surface of the tank top wall.
This patent application is a continuation-in-part of U.S. Patent Application 09/873,032 filed June 1, 2001. This patent application also claims the benefit of U.S. Provisional Patent Application 60/371,778, filed April 11, 2002 and U.S. Provisional Patent Application 60/391,556 filed June 25, 2002.
This invention pertains to tanks for storing and dispensing fluids, and in particular, to such tanks which are mobile and mounted on vehicles.
Dust control can be a particular problem on construction sites, building demolition sites, excavation sites and mine sites. For example, in a mining operation, the mine haul roads essentially consist of dirt and gravel. Dust control is necessary on the haul roads so that the operators of mining vehicles can readily see the other mining vehicles using the roads. Thus, dust control on mine haul roads is a safety issue. Moreover, dust clouds caused by vehicles operating on the haul roads can adversely impact air quality potentially creating environmental issues particularly where the dust clouds drift beyond the mine site.
Typically, mines have water tanker trucks, which are used to water down the haul roads in order to control dust. Such water tanker trucks generally have a plurality of spray nozzles positioned on either the forward or rearward sections of the vehicles to dispense a fluid spray or mist onto the ground. The water tanker truck can also have hoses or a water monitor/cannon for washing down other mining equipment and, in some cases, fire control.
Because of the service demands on such water tanker trucks, they are typically capable of carrying very large quantities of water. For example, water tanker trucks used in mining operations can have fluid capacities of over 50,000 gallons. Of course, vehicle stability is a critical issue when transporting large volumes of water that, in the case of a 50,000 gallon tank, can carry a water load of over 200 tons. Specifically, surging and wave motion of the fluid, particularly transverse surging resulting from centrifugal forces experienced during turning of the truck can cause a tanker truck to become unstable or even turn over on its side. To prevent such surging of the fluid, the tank is provided with internal baffles.
To ensure a long-life, the interior of the tanks must undergo periodic maintenance. For example, to protect against corrosion, the interior surfaces of the tank may need to be periodically cleaned and re-coated with a rust protection coating such as an epoxy. This work is complicated by the fact that tanks only have points of entry on the top of the tank and often just a single point of entry, and thus the work is subject to confined space safety regulations. Accordingly, workers performing tasks inside the tank must be provided with secondary air sources from outside the tank. This can greatly complicate the maintenance operations. Moreover, it can be difficult for the workers to maneuver around the internal tank baffles particularly since the interior of the tank is very dark. Accordingly, maintaining the interior of these tanks can be a difficult and time-consuming process.
Another problem with these types of mobile tanks is that at larger sizes they can be difficult to ship to the location at which they are to be used, typically on off-highway trucks. For instance, the largest tanks can be over twenty feet wide. As can be appreciated, transporting a tank of this size can be a difficult and expensive operation.
Accordingly, in view of the foregoing, a general object of the present invention is to provide an improved baffled tank for a tanker truck such as is used for dust control in mining operations, construction sites and the like.
A more specific object of one embodiment of the present invention is to provide a tank for such a tanker truck which has an improved baffling system.
Another object of one embodiment of the present invention is to provide a baffled tank for such a tanker truck which is configured so that work can much more easily be performed inside the tank.
Referring now more particularly to
Optionally, as in the illustrated embodiment, the tank 12 can be attached to the chassis 14 for pivotal movement into a raised position so as to allow access to components on the tanker truck 10 such as the drive train, transmission, or gear differential. The tank 12 can be moved between the raised and lowered positions by actuation of a hoist cylinder 18 carried on the chassis 14 of the tanker truck 10. As will be appreciated, the tank 12 can also be rigidly mounted on the chassis 14.
The tank 12 consists of a pair of opposing sidewalls 20, a rear wall 22, a front wall 24, a top wall 25 and a floor 26. In this case, the floor 26 includes the components for mounting the tank to the chassis including the tank/chassis pivots 28 and the mounts 30 for the hoist cylinder 18 (see, e.g., FIGS. 1 and 7). The floor support structure includes the longitudinally extending tank frame rails 31 and a plurality of laterally extending cross supports 33. This floor support structure adds to the structural integrity of the tank 12. Moreover, because the floor 26 of the tank 12 follows the top of the truck frame, the tank is mounted lower on the truck chassis improving the stability of the tank and, in turn, the tanker truck. In the illustrated embodiment, as shown in
For discharging fluid, the tank 12 includes, in this case, a plurality of spray nozzles which are supplied by a spray bar assembly 32 arranged on the exterior of the rear wall 22 of the tank 12 and in communication with a fluid pump mounted on the rear of the tank 12. As shown in
In a conventional manner, the top wall 25 of the tank 12 includes a fill hole 38, as shown
In accordance with an important aspect of one embodiment of the present invention, the tank 12 includes a novel baffle system in which the structural components of the tank also serve as baffles. Moreover, as described in detail below, the baffle system can also be configured to make the interior of the tank 12 much more accessible to workers than baffled tanks that are presently available. The baffle system is best described by separating the tank into a center section 46 best shown in
In order to allow the tank 12 to be shipped more easily to a location where it is assembled to an off-highway truck, the center, left and right side sections 46, 48, 50 can comprise separate components that are assembled together. In particular, as shown in the exploded view of
To suppress wave motion and surging of the fluid in the lateral or side-to-side direction, the center section 46 has longitudinal baffles that generally form an X-shaped baffle arrangement 52 (see
A plurality of holes 64 are provided in the upper and lower surfaces 60, 62 (best shown in
To assist fluid migration and also provide access for workers performing maintenance operations, openings 68 are provided, in this instance, in the middle of upper and lower legs 56, 58 of the longitudinal X-shaped baffle arrangement 52 as shown in
For limiting longitudinal wave action and surging of fluid such as during braking or acceleration of the tanker truck 10, vertically extending baffles are arranged between the legs of the X-shaped baffle arrangement 52. As shown in
Additional lateral baffling can also be provided to either side of the center section 46 in the left and right side sections 48, 50. As shown in
Lateral baffle doors 88 are provided in each side section 48, 50 that extend between the C-shaped ribs 82 and the center X-shaped baffle arrangement 52 as shown, for example, in
For supporting the hinged baffle doors 88, a plurality of longitudinally spaced upright support members 92 that extend between the floor 26 and top wall 25 of the tank 12 are provided on either side of the center section 46 as shown in
The hinged baffle doors 88 allow the side sections 48, 50 to be constructed in a manner similar to the hull of a ship with the C-shaped ribs 82 supporting the walls of the tank 12. However, the C-shaped ribs 82 also form part of the lateral baffling in the tank 12 when the hinged baffle doors 88 are closed. Thus, the illustrated baffling configuration also allows the structural components of the side sections of the tank 12 to also serve as baffles. Alternatively, the C-shaped ribs 82 could be arranged on the exterior surface of the tank 12 with the hinged baffle doors 88 being latched directly to the inside surface of the sidewalls 20. Attaching the hinged baffle doors 88 to the center section 46 can also permit the left and right side sections 48, 50 to be interlocked for shipment on a single truck. The center section 46 then can be shipped separately with the hinged baffle doors 88 swung into the longitudinally extending open position against the outside of the X-shaped baffle arrangement 52.
According to a further aspect of the present invention, to relieve concerns regarding working in a confined space and thereby eliminate the necessity for an external secondary air supply, the tank 12 can include entry hatches 100 in the sides and/or ends of the tank. In this instance, an entry hatch 100 is provided in both the front wall 24 and rear wall 22 of the tank 12 for each of the tank sections 46, 48, 50. In particular, as best shown in
When work must be performed inside the tank, the hatches 100 can be opened to provide light and air into the interior of the tank. By swinging the hinged baffle doors 88 into their open positions and removing the loose fitting hatch plates 91 on the access openings in the various baffles, all of the compartments inside the tank 12 can be easily accessed thereby minimizing confined space concerns. Moreover, with the hinged baffle doors 88 in the open position, workers can see and walk from one end of the tank 12 to the other substantially unobstructed. If sized appropriately, the entry hatches 100 can also allow the hinged baffle doors 88 or other internal baffling structures to be inserted into or removed from the interior of the tank 12 after the components are assembled together.
To facilitate installation and removal of the tank from a tanker truck chassis, a plurality of uniquely configured lifting eyes 804 can be disposed on the upper surface of the tank. Such lifting eyes 804 are shown with respect to an exemplary tank 802 in
In an alternative embodiment illustrated in
Advantageously, with the illustrated embodiment, the pivotal baffle doors 202 also can be formed from the pieces that are cut out of the baffles 204 to create the access openings 210. Specifically, for a particular pivotal baffle door 202, the door skeleton is first cut out of (
In the embodiment illustrated in
An alternative baffle system incorporating an X-shaped longitudinal baffle arrangement 352 that is particularly suited for relatively smaller tanks is shown in
To limit longitudinal wave action and surging of fluid, vertically extending lateral baffles 372, 374 and 376 are arranged between the upper 356 and lower baffle legs 358 of the X-shaped longitudinal baffle arrangement 352. Specifically, an upper lateral baffle 372 is provided between the upper baffle legs 356 and a lower lateral baffle 374 is provided between the lower baffle legs 358 at spaced intervals along the length of the X-shaped longitudinal baffle arrangement 352. Moreover, side lateral baffles 376 are provided to either side of the X-shaped longitudinal baffle arrangement 352 at spaced intervals along the length thereof. To provide access into the compartments formed in the upper and lower portions of the X-shaped longitudinal baffle arrangement by the lateral baffles 372, 374 and 376, access openings 378 are provided in each of the upper 372 and lower lateral baffles 374. At least one of the access openings 368 in the upper 356 and lower baffle legs 358 is also arranged between each pair of upper 372 and lower lateral baffles 374 and side lateral baffles 376 to ensure that there is adequate access into each of the compartments defined by the baffles. Each of these access openings 368, 378 is configured to receive an associated pivotal baffle door like the baffle doors 202 illustrated in
Another baffle system particularly suited for relatively small tanks is shown in
To drive the fluid pump associated with the tank, a hydraulic motor can be provided which is, in turn, powered by the hydraulic system of the tanker truck. Specifically, tanks that are to be used in off-highway applications are often mounted to off-highway dump or scraper trucks that have been converted by removal of the dump body or scraper bowl. Such trucks typically are equipped with a hydraulic fluid system that can be used to drive a hydraulic motor and fluid pump associated with the tank. Because the hydraulic systems on these trucks are typically used for dumping loads, they can produce relatively high flow rates and pressures. For example, depending on the vehicle size, the hydraulic systems on these trucks may produce a flow rate of 100-200 gallons per minute at a pressure of up to 2500-3000 psi at normal truck engine operating speeds. Such flow rates and pressures do not pose problems for the hydraulic cylinders that are typically used to dump loads. However, these flow rates and pressures can cause problems when the truck hydraulic system is tied into a hydraulic motor such as is used to power the fluid pump for a tank.
In particular, starting the hydraulic motor at the full fluid flow and pressure that the truck’s hydraulic system produces at normal engine operating speeds can subject the hydraulic motor and the fluid pump associated with the tank to a significant shock load. For example, the hydraulic motor associated with a tank may be designed to turn at approximately 2000 RPM at full hydraulic flow. Thus, in such a case, at start-up, the hydraulic motor essentially would have to accelerate instantaneously to 2000 RPM in order to alleviate the shock of the hydraulic fluid supplied by the truck hydraulic system. Obviously, the hydraulic motor is not capable of such rapid acceleration. Moreover, since the hydraulic motor is connected through a coupling to the fluid pump, the inertia caused by the fluid pump impeller and any fluid in the pump also has to be overcome at start-up. Thus, unless the hydraulic motor is engaged at a fairly low hydraulic flow, i.e. idle RPM of the transport vehicle, the hydraulic motor and the fluid pump will be subjected to substantial shock loads at start-up. These shock loads could over time result in damage to the coupling between the hydraulic motor and the fluid pump as well as damage to the hydraulic motor itself.
To help protect the hydraulic motor and fluid pump during start-up, a soft start/stop system can be provided. With reference to
Once the hydraulic pressure relief valve 502 opens, the hydraulic fluid flow that the hydraulic motor 504 is unable to accept as it accelerates to full operating speed is allowed to bypass the hydraulic motor 504 through the parallel bypass line 506 and return to the truck hydraulic fluid tank 508. As the hydraulic motor 504 begins to come up to normal operating RPM, it is able to accept more of the hydraulic fluid thereby reducing the pressure at the inlet to the hydraulic pressure relief valve 502. As a result, the hydraulic pressure relief valve 502 gradually closes so that more of the hydraulic fluid flow from supply line 510 goes through the hydraulic motor 504. Once the hydraulic motor 504 nears or reaches its normal operating RPM, the hydraulic pressure relief valve 502 closes completely and all the hydraulic fluid from the truck hydraulic supply line 510 flows through the hydraulic motor 504 allowing the fluid pump to operate at full capacity.
Alternatively, instead of a standard pressure relief valve, a so-called “soft start pressure relief valve” could be used (see FIG. 38A). A soft start pressure relief valve differs from a standard pressure relief valve in that in its normal non-operative state, the soft-start valve is open. Thus, instead of allowing hydraulic fluid to bypass around the hydraulic motor 504 only after the pressure has built to a certain value, during start-up of the hydraulic motor, the soft-start valve initially permits all of the hydraulic fluid to bypass the hydraulic motor 504 and return to the truck hydraulic fluid tank 508. Then, over a prescribed time interval (e.g., 250 milliseconds), the soft-start valve gradually closes thereby allowing the pressure at the hydraulic motor 504 to gradually build. Thus, the soft-start pressure relief valve limits the rate at which the pressure at the hydraulic motor 504 rises. Once closed, the soft-start valve functions as a normal pressure relief valve limiting the maximum system pressure. An example of a soft-start pilot operated relief valve that could be used in the soft start/stop system of the present invention is the RPGT valve available from Sun Hydraulics. Of course, it will be appreciated that other soft-start valves could also be used.
To permit the hydraulic motor 504 to softly coast to a stop, a one-way check valve 514 can be installed in the bypass line 506 parallel to the hydraulic pressure relief valve 502 that would allow hydraulic fluid to circulate from the outlet port of the hydraulic motor 504 through the bypass line 506 and back to the fluid supply line 510 and the inlet port of the hydraulic motor 504. The check valve 514 is configured to block flow in the direction from supply line 510 ensuring that the hydraulic pressure relief valve 502 controls the flow of hydraulic fluid from supply line 510 through the bypass line 506 towards the truck hydraulic fluid tank 508. This arrangement creates a closed loop that allows the momentum of the turning hydraulic motor and pump to gradually dissipate when the supply of hydraulic fluid from the truck hydraulic system is shut-off.
Tanker trucks used in environments like construction sites, building demolition sites, excavation sites and mine sites are often filled with polluted water. In particular, these sites may have run-off collection ponds from which polluted non-potable water is pumped for use in tanker trucks. This polluted water may have a high degree of suspended solids. Since this water is used for various non-drinking purposes, these pollutants/suspended solids in no way inhibit the operation or effectiveness of these tanks. However, these suspended solids may settle to the tank floor or onto other internal tank surfaces (e.g., baffles) as sediment if a tanker truck is allowed to sit for any period of time. This sediment, depending on its chemical makeup, may cause accelerated corroding of the floor, baffles or other surfaces in the tank even if stainless steel is used.
To help keep such sediment from settling on the tank floor, the tank of the present invention can include a tank agitation system. In particular, the tank can include a closed loop fluid circuit which draws fluid from the tank through the tank fluid pump and pumps it back into the tank at a high flow rate and pressure in order to agitate the contents of the tank. This agitation system could be operated, either automatically or manually, when fluid is not being dispersed from the tank such that the tank fluid pump runs semi-continuously.
An illustrative embodiment of a fluid agitation system constructed in accordance with the present invention is shown in
To provide agitation of the fluid in the baffled tank 600, a plurality of short cross tubes 608 as well as a plurality of apertures 610 are provided in the surface of the agitation tube 602. Each of the short cross tubes 608 consists of a tube which branches off from the agitation tube 602 at an angle from perpendicular. As can be seen from the top view of
The various components of the agitation system are shown in
To simplify tank-filling operations when filling the tank to less than its full capacity, the tank can be equipped with a variable volume system. Such a variable volume system is shown with respect to an exemplary tanker truck 702 in
To permit the tank 706 to be filled to maximum capacity, the variable volume system further includes an air releasing control mechanism. The air releasing control mechanism provides a way by which the air can bleed or vent out of the tank 706 once the fluid level reaches and then rises above the lower or bottom edge 713 of the fill tube 704 during a filling operation. To permit the fluid to rise to the maximum level in the tank 706, the outlet point of the air releasing control mechanism (i.e., through which air outlets from the tank) should be located as close as possible to the top wall 710 of the tank 706. In the embodiment illustrated in
To allow the maximum fill level to be set at other levels, the variable volume system could include a plurality of air releasing control mechanisms each of which has an air outlet at a different vertical level in the tank. For example, in the embodiment illustrated in
Alternatively, the variable volume system could include an air releasing control mechanism that is configured such that the vertical level at which the pressure relief mechanism outlets air from the interior of the tank can be selectively adjusted. For example, as shown in
An alternative arrangement for the variable volume system is illustrated in
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventor for carrying out the invention. Of course, variations of those preferred embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventor intends for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context