WO2014207486A1

WO2014207486A1 - Mobile liquid tank

Info

Publication number: WO2014207486A1
Application number: PCT/GB2014/051978
Authority: WO
Inventors: Stuart J. BADCOCK
Original assignee: Articulated Truck Solutions Llp
Priority date: 2013-06-28
Filing date: 2014-06-30
Publication date: 2014-12-31
Also published as: GB2515558A; GB201311629D0

Abstract

The present invention relates to a mobile liquid tank, and vehicles comprising such a tank, for the transport of liquids. A mobile liquid tank (10) for transporting fluids is provided, in which a plurality of baffles (115) (running longitudinally and laterally) are located in the tank. The perpendicularly oriented baffles define a plurality of baffle cells (117). Channels (118) are provided in the baffles to enable liquid to flow from one cell to a neighbouring cell, and to permit inspection and cleaning of the tank. Each of the baffle channels is provided with a valve, preferably a flap valve, which are arranged such that liquid is permitted to flow freely in a direction inwardly from the walls of the tank, and arranged to restrict the flow of liquid outwardly towards the walls.

Description

Mobile Liquid Tank

FIELD OF THE INVENTION The present invention relates to a mobile liquid tank, and vehicles comprising such a tank, for the transport of liquids.

BACKGROUND OF THE INVENTION Water tanks are used, for example, for the suppression of dust created through the use of haul roads on construction, quarrying and mining sites amongst others. The roads on these sites are very often little more than dirt roads, so that as equipment and vehicles are moved a dust cloud can be created if the dirt is not damped in some way. Often the easiest way to do this is by spraying water from a vehicle. The vehicle can be loaded in various ways, some of these involve pumping water from a nearby ground source such as a pond or lake, or through the use of water towers and flood loading the top through an open fill hole in the top of the tank. The water used is rarely particularly clean, it often has high levels of acid or alkaline, and / or particles of dirt, slurry, or other large particles.

Due to the large quantities of water these machines are to carry to effectively dampen a significant area there size can be anything up to 200000 litres of water. This amount of water requires baffles within the tank to help reduce the effect of the water moving as the vehicle is driven. The force of the water moving as a vehicle corners is significant enough to roll a truck on its side.

Because of the environment these tanks work in, maintenance is required regularly within the tank itself. Normally an epoxy type resin is used to help reduce corrosion within the tank. This means that access is required for a person to apply such a coating and to maintain the internal structure of the tank. For this reason large channels have to be provided within any internal baffling. These channels are usually left open, especially on smaller tanks meaning that the effectiveness of the baffling system is drastically reduced. As such, the machine is liable to tipping over, causing not only considerable damage but also posing a huge risk to operator safety. Figures 1 a to 1 c show a known baffled tank 10, which comprises a base 1 1 , side walls 12, front wall 13 and rear wall 14. Arranged inside the tank 10 along the base 1 1 are a plurality of longitudinal baffles 15 running from the front wall 13 to the rear wall 14, and a plurality of lateral baffles 16 running between the side walls 12. The longitudinal baffles 15 and lateral baffles 16 are arranged generally perpendicular to one another, and intersect to define a plurality of baffle cells 17. Arranged in the baffles 15, 16 are a plurality of baffle channels 18, which are dimensioned to permit inspection and the carrying out of repair work. Also provided in the tank 10 are a plurality of air channels 20, along an upper portion 19, which permit the flow of air between baffle cells 17 (i.e. to prevent the build up of a vacuum between cells 17 when the liquid is moving between cells), and a plurality of liquid channels 21 , to permit the flow of liquid between cells 17.

The liquid channels 21 are used for the dispersal of the liquid within the tank 10. Since the tank may be used for the delivery of liquid to a surface (for example a road surface), the liquid needs to drain from each cell to an area of the tank so that it may be sprayed through a number of spray heads.

Figures 2a to 2c show the baffled tank 10 of figure 1 when half-filled with a liquid, with the tank being inclined (figure 2b) and tilted to its side (figure 2c).

Due to the relatively large baffle channels 18, required for inspection and maintenance, the baffles offer little resistance to the movement of the liquid being contained in the tank when the tank is inclined or tilted. From a resting position (figure 2a) to an inclined (figure 2b) or tilted (figure 2c) position, the liquid may take only a few seconds (in the region of 2 to 5 seconds) to move to the levels 22 shown in the figures.

Given that the volume of liquid in the tank 10 can be large, such a volume of liquid moving so rapidly around the tank, relatively unhindered by the baffles, may cause the vehicle carrying the tank 10 to topple over as the weight of the liquid moves from one side to another or from one end to another. SUMMARY OF THE INVENTION

We have therefore appreciated the need for an improved tank for the transport of liquids in which the risk of toppling is reduced.

The present invention therefore provides a mobile liquid tank for the transport of liquids, comprising: a body for receiving a liquid, the body having a base and a plurality of walls to define a tank; a first plurality of baffles extending longitudinally along the base between opposite walls of the body; and a second plurality of baffles extending laterally along the base between opposite walls of the body, the second plurality of baffles being arranged generally perpendicular to and intersecting the first plurality of baffles to define a plurality of baffle cells, wherein each of the first and second baffles comprises a plurality of baffle channels extending between first and second surfaces, each of the baffle channels in each of the baffles corresponding with one of the plurality of baffle cells, and the baffle channels being arranged to permit liquid to pass from one baffle cell to a neighbouring baffle cell; and wherein each of the baffle channels comprises a valve for restricting the flow of liquid through the baffle channel.

Advantageously, by providing the baffle channels with valves, flow can be restricted to prevent sloshing of the liquid, which would ordinarily result in a dramatic shift in weight as the liquid moves from one side of the tank to the other (which can cause a vehicle to topple).

Preferably, each valve is arranged to, in use, permit liquid to flow freely in a direction inwardly of the body and to restrict the flow of liquid outwardly towards the walls.

The tank may have an upper portion opposing the base that is closed. In this case, the first and second plurality of baffles extend between the base and upper portion. Each baffle cell may comprise one or more air channels proximal the upper portion to permit air to pass from one baffle cell to a neighbouring baffle cell. These air channels prevent vacuum built-up when the liquid in the tank moves between baffle cells. As such, the liquid is able to move more freely. Each of the second plurality of baffles (i.e. the lateral baffles running from side to side of the tank) may comprise a plurality of liquid channels proximal the base, each of the plurality of liquid channels corresponding with one of the baffle cells, the liquid channels being arranged to permit liquid to pass from one baffle cell to a neighbouring baffle cell in a longitudinal direction of the tank, and wherein the plurality of liquid channels are smaller than the baffle channels.

Furthermore, each of the first plurality of baffles (i.e. the longitudinal baffles running from the front to the rear of the tank) may comprise a liquid channel proximal the base, the liquid channel corresponding with a baffle cell longitudinally disposed at the rear of the tank, the liquid channel being arranged to permit liquid to pass from one baffle cell to a neighbouring baffle cell in a lateral direction of the tank, and wherein the liquid channel is smaller than the baffle channels. The valves may comprise flap valves. The flap valves may be removable to enable them to be replaced or maintained easily.

The present invention also provides a vehicle comprising the mobile liquid tank described above.

LIST OF FIGURES

The present invention will now be described, by way of example only, and with reference to the accompanying figures, in which:

Figure 1 shows a known baffled tank;

Figure 2 shows a known baffled tank containing a liquid and being inclined (figure 2b) and tilted on its side (figure 2c);

Figure 3 shows a mobile liquid tank according to the present invention; Figure 4 shows the tank of figure 3 containing liquid and being inclined; and Figure 5 shows the tank of figure 3 containing liquid being levelled following the steps of figure 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In brief, the present invention provides a mobile liquid tank for transporting fluids, in which a plurality of baffles (running longitudinally and laterally) are provided in the tank. The perpendicularly oriented baffles define a plurality of baffle cells. Channels are provided in the baffles to enable liquid to flow from one cell to a neighbouring cell, and to permit inspection and cleaning of the tank. Each of the baffle channels is provided with a valve, preferably a flap valve, which are arranged such that liquid is permitted to flow freely in a direction inwardly of the body of the tank, and arranged to restrict the flow of liquid outwardly towards the walls. Advantageously, use of valves (e.g. flap valves) in the mobile liquid tank means that inspection and maintenance access is available when required by simply hanging the flap away from the hole so that light and air can move easily. They may be constructed of rubber, in which case they will not rust and will remain effective even if some damage should occur. Furthermore, they may be replace easily with the removal of a few bolts on each valve.

Figures 3a to 3d show a mobile liquid tank 1 10 according to the present invention. The tank 1 10 comprises a base 1 1 1 , side walls 1 12, front wall 1 13 and rear wall 114. Arranged inside the tank 1 10 along the base 1 1 1 are a plurality of longitudinal baffles 1 15 running from the front wall 1 13 to the rear wall 1 14, and a plurality of lateral baffles 1 16 running between the side walls 1 12. The longitudinal baffles 1 15 and lateral baffles 1 16 are arranged generally perpendicular to one another, and intersect to define a plurality of baffle cells 1 17. Arranged in the baffles 1 15, 1 16 are a plurality of baffle channels 1 18, which are dimensioned to permit inspection and the carrying out of maintenance. Also provided in the tank 1 10 are a plurality of air channels 120, along an upper portion 1 19, which permit the flow of air between baffle cells 1 17 (i.e. to prevent the build up of a vacuum between cells 1 17 when the liquid is moving between cells), and a plurality of liquid channels 121 , to permit the flow of liquid between cells 1 17. The liquid channels 121 are used for the dispersal of the liquid within the tank 1 10. Since the tank may be used for the delivery of liquid to a surface (for example a road surface), the liquid needs to drain from each cell to an area of the tank so that it may be sprayed through a number of spray heads. In the present invention, liquid channels 121 are provided in each of the lateral baffles (one liquid channel per baffle cell on each of the lateral baffles). On the longitudinal baffles 1 15, liquid channels 121 are only present in the rear-most baffle cells 1 17 (i.e. the baffle cells 1 17 adjacent the rear 1 14 of the tank 1 10). Each of the baffle channels 1 18 comprises a valve 130 for restricting the flow of liquid through the baffle channel 1 18. Preferably, the valve 130 is a flap valve (which may be constructed from rubber). The flap valve 130 may be integral with the baffle channel 1 18 or it may be mounted to the baffle proximal the respective baffle channel 130, for example hung on fixings on the baffle, and configured to swing away from the baffle to open, and to rest against the baffle to close the baffle channel.

The valves 130 are arranged to, in use, permit liquid to flow freely in a direction inwardly of the body (i.e. from an outside wall 1 12, 1 13, 1 14 towards the centre of the tank), and to restrict the flow of liquid outwardly towards the walls of the tank. Figure 3d shows the direction in which liquid may flow unrestricted through the valves 130 (the free-flowing direction of the liquid shown using large arrows). The valves 130 prevent liquid flowing in a direction that is opposite the direction indicated by the arrows.

Whilst the valves 130 prevent or restrict the flow of liquid in a direction that is outward (i.e. from the centre of the tank 1 10 towards the sides 1 12, front 1 13 or rear 1 14), liquid may still flow in that direction through the liquid channels 121 in the lower portion of the baffles 1 15, 1 16. However, since the dimension of the liquid channels 121 is much less than the dimensions of the baffle channels 1 18, the flow is much reduced. It will be noted from figures 3a and 3d that valves 130 are provided on either side of the central lateral baffle 1 16. This prevents liquid from flowing freely between front baffle cells (i.e. baffle cells 1 17 forward of the central lateral baffle towards the front of the tank 1 13) and the rear baffle cells (i.e. baffle cells 1 17 rearward of the central lateral baffle towards the rear of the tank 1 14). The operation of the mobile liquid tank 1 10 will now be described with reference to figure 4, which shows a half-full tank being inclined from a horizontal position, and figure 5, which shows the half-full tank being returned from an inclined position (as shown in figure 4c) to a horizontal position.

In figure 4a, which shows the liquid level 122a, 122b, 122c, 122d immediately after the tank has been inclined (for example by a vehicle beginning its ascent of a slope - the front 1 13 is inclined from the rear 1 14). The liquid level 122a, 122b, 122c, 122d is approximately equal in each of the baffle cells 1 17.

Figure 4b shows the liquid level 122a, 122b, 122c, 122d shortly after figure 4a. Since the valves 130 are configured such that liquid flows freely inbound of the tank walls and sides, but is restricted or prohibited from flowing through the baffle channels 1 18 in the opposite direction, liquid levels 122a and 122b rapidly equalise (since liquid has flown from the front most baffle cell towards the central baffle cell). Liquid levels 122c and 122d remain largely unaffected, since the valves 130 are configured to prevent liquid flowing from central to outer baffle cells. However, a relatively small volume of liquid will have transferred from 122c to 122d via the smaller liquid channels 121 located in the lateral baffles 1 16. As such, the rate at which the volume of liquid is transferred to the rear 1 14 of the tank has been controllably limited by the valves and liquid channels to prevent sudden sloshing of a large volume of liquid to the rear of the tank, which may cause the tank to topple over or cause general instability in the vehicle carrying the tank. Figure 4c shows the liquid levels 122a, 122b, 122c and 122d after figure 4b, and once the levels have settled to a steady state. Over time, liquid has flown rapidly from 122a to 122b via the baffle channel 1 18 and a liquid channel 121 in the baffle. Furthermore, liquid has flown at a reduced or restricted rate from 122b to 122c, and 122c to 122d via the smaller liquid channels 121 located in each of the lateral baffles 1 16 only. That is, the valves 130 have prevented more rapid flow from 122b to 122c and from 122c to 122d because the more rapid flow is preferably inbound from the outside to the centre of the tank.

The time between the states of liquid levels in figure 4a to figure 4c could be in the region of 15 seconds (although this is an illustrative example only), which is much longer (in the region of 5 to 10 times longer) than the liquid level transfer rate in known tanks. As such, the risk of toppling of the vehicle carrying the tank of the present invention is reduced. Figure 5 shows the half-full tank being returned from an inclined position (as shown in figure 4c) to a horizontal position.

In figure 5a, which shows the liquid level 122a, 122b, 122c, 122d immediately after the tank has been brought into the horizontal position (for example once the vehicle has reached a plateau during its ascent). The liquid levels 122a, 122b, 122c, 122d are stepped from 122a having the least to 122d having the most, since the liquid in the tank was positioned to the rear 1 14 of the tank during the ascent.

Figure 5b shows the liquid level 122a, 122b, 122c, 122d shortly after figure 5a. Since the valves 130 are configured such that liquid flows freely inbound of the tank walls and sides towards the centre, but is restricted or prohibited from flowing through the baffle channels 1 18 in the opposite direction, liquid levels 122c and 122d rapidly equalise (since liquid has flown from the rear most baffle cell towards the central baffle cell). Liquid levels 122a and 122b remain largely unaffected, since the valves 130 are configured to prevent liquid flowing from central to outer baffle cells (in this case the most forward baffle cell). However, a relatively small volume of liquid will have transferred from 122b to 122a via the smaller liquid channels 121 located in the lateral baffles 1 16. As such, the rate at which the volume of liquid is transferred to the front 113 of the tank has been controllably limited by the valves and liquid channels to prevent sudden sloshing of a large volume of liquid to the front of the tank, which may cause the tank to topple over, or cause instability in the handling of the vehicle.

Figure 5c shows the liquid levels 122a, 122b, 122c and 122d after figure 5b, and once the levels have settled to a steady state (i.e. approximately equal in all baffle cells 1 17). Over time, liquid has flown rapidly from 122d to 122c via the baffle channel 1 18 and liquid channels 121 in the lateral baffles 1 16. Furthermore, liquid has flown at a reduced or restricted rate from 122c to 122b, and 122b to 122a via the smaller liquid channels 121 located in each of the lateral baffles 1 16 only. That is, the valves 130 have prevented more rapid flow from 122c to 122b and from 122b to 122a because the more rapid flow is preferably inbound from the outside to the centre of the tank. The time between the states of liquid levels in figure 5a to figure 5c could be in the region of 15 seconds (although this is an illustrative example only), which is much longer (in the region of 5 to 10 times longer) than the liquid level transfer in known tanks. As such, the risk of toppling of the vehicle carrying the tank of the present invention is reduced.

The same principle as described above is also applicable when the vehicle is driven so that the tank is tilted (i.e. from side to side) rather than inclined front to rear. The valves 130 will allow rapid flow of liquid from the outer baffle cells to the inner or more central baffle cells, and the liquid channels allow slower flow of the liquid to other baffle cells to spread the volume of liquid between the remaining baffle cells. However, as it can be seen, liquid channels 121 are only provided in the longitudinal baffles 1 15 in the rearmost baffle cells 1 17. Fewer liquid channels 121 in the longitudinal baffles 1 15 means that the rate of flow of liquid in the outbound direction is reduced even further when compared to the flow of liquid in the outbound direction given in the examples shown in figures 4 and 5, since outbound liquid must flow first to the rear baffle cells 1 17 through the liquid channels 121 in the lateral baffles 1 16 and then flow forward again via the baffle channels 121 in the lateral baffles 1 16.

As described above, the tank may be used for the dispersal of the contents rather than just the carriage. As such, it is preferable to allow the water to drain from each compartment to an area of the tank so that it may be sprayed through a number of spray heads, this is normally achieved by allowing the water to flow around the bottom of the tank via the liquid channels, which allows the water to drain under gravity to an area where it can be pumped through pipe work to the spray heads. It is best that the water drains evenly throughout the tank to ensure that the weight distribution on the vehicles axles is even so as to not destabilise the vehicle or cause damage to the chassis underneath the tank due to unevenly distributed loads. It is noted that the liquid channels 121 should be adequately sized for the movement of liquid, allowing for any residue build up from consistent use.

There is a greater possibility of the vehicle rolling or toppling during the time that the liquid in the tank is unevenly distributed around the tank. The use of the valves 130 thus reduces this possibility because they enable a bulk volume of the load to move from an outer extreme position to a more central position relatively quickly, without allowing the water to surge between compartments in a direction away from the central compartments.

When the vehicle is driven across bumpy terrain (i.e. where the vehicle is not inclined or tilted for prolonged periods of time), liquid is generally retained in the respective baffle cell 1 17.

Although the present invention has been described hereinabove with reference to specific embodiments, the present invention is not limited to the specific embodiments and modifications will be apparent to a skilled person in the art which lie within the scope of the claims.

Claims

CLAIMS:

1. A mobile liquid tank for the transport of liquids, comprising:

a body for receiving a liquid, the body having a base and a plurality of walls to define a tank;

a first plurality of baffles extending longitudinally along the base between opposite walls of the body; and

a second plurality of baffles extending laterally along the base between opposite walls of the body, the second plurality of baffles being arranged generally perpendicular to and intersecting the first plurality of baffles to define a plurality of baffle cells,

wherein each of the first and second baffles comprises a plurality of baffle channels extending between first and second surfaces, each of the baffle channels in each of the baffles corresponding with one of the plurality of baffle cells, and the baffle channels being arranged to permit liquid to pass from one baffle cell to a neighbouring baffle cell; and

wherein each of the baffle channels comprises a valve for restricting the flow of liquid through the baffle channel.

2. A mobile liquid tank according to claim 1 , wherein each valve is arranged to, in use, permit liquid to flow freely in a direction inwardly of the body and to restrict the flow of liquid outwardly towards the walls.

3. A mobile liquid tank according to claim 1 or 2, wherein an upper portion opposing the base is closed, and wherein the first and second plurality of baffles extend between the base and upper portion.

4. A mobile liquid tank according to claim 3, wherein each baffle cell comprises one or more air channels proximal the upper portion to permit air to pass from one baffle cell to a neighbouring baffle cell.

5. A mobile liquid tank according to any preceding claim, wherein each of the second plurality of baffles comprises a plurality of liquid channels proximal the base, each of the plurality of liquid channels corresponding with one of the baffle cells, the liquid channels being arranged to permit liquid to pass from one baffle cell to a neighbouring baffle cell in a longitudinal direction of the tank, and wherein the plurality of liquid channels are smaller than the baffle channels.

6. A mobile liquid tank according to any preceding claim, wherein each of the first plurality of baffles comprises a liquid channel proximal the base, the liquid channel corresponding with a baffle cell longitudinally disposed at the rear of the tank, the liquid channel being arranged to permit liquid to pass from one baffle cell to a neighbouring baffle cell in a lateral direction of the tank, and wherein the liquid channel is smaller than the baffle channels.

7. A mobile liquid tank according to any preceding claim, wherein the valves comprise flap valves.

8. A mobile liquid tank according to claim 7, wherein the flap valves are removable.

9. A vehicle comprising a mobile liquid tank according to any one of claims 1 to 8.

10. A mobile liquid tank substantially as herein described with reference to the accompanying figures.