EP3700777A1

EP3700777A1 - A tanker

Info

Publication number: EP3700777A1
Application number: EP18811366.6A
Authority: EP
Inventors: Trevor Glenn CRUIKSHANK
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-10-27
Filing date: 2018-10-24
Publication date: 2020-09-02
Also published as: WO2019082173A1

Abstract

A slurry tanker (1) comprising a cylindrical tank (2) defining a slurry reservoir (9) subdivided into a front self-contained slurry ballast chamber (10) and a rear self-contained slurry chamber (11) in which the ballast chamber (10) serves to contain slurry towards the front end of the slurry tanker to keep the weight of the fluid in the slurry reservoir towards the front of the cylindrical tank while emptying thus keeping the weight of that fluid on the wheels of a drawing vehicle for as long as possible to enhance vehicle traction.

Description

A Tanker

Introduction This invention relates to a tanker for spreading or transporting fluids and more particularly to a tanker for spreading or transporting liquids such as slurry.

Background of the Invention Tankers are widely used for the transportation and spreading of various fluids ranging from gases to liquids to slurries (liquids such as water in which solid materials are dispersed). Tankers can be in the form of standalone vehicles or can be drawn by other vehicles such as tractors and the like. For example, slurry tankers used in agriculture for the transportation and spreading of animal slurry can range in capacity from about 4000 litres to in excess of 23000 litres and are typically drawn by tractors when transporting or spreading the slurry. Such slurry tankers are generally made up of an air pump and a tank into which slurry is drawn by causing the pump to evacuate the tank. Slurry is expelled from the tank and spread via a nozzle/deflector plate or trailing shoes/dribble bars attached to the tanker by causing the pump to pressurise the slurry in the tank.

However, due to the increasingly large capacities of tankers and in particular slurry tankers, the tankers can become dangerously unbalanced during movement of the tankers - particularly when the tanker is only partially full as the slurry within the tank is "live" i.e. can move within the tank e.g. during spreading operations. Therefore, as an operator begins to spread the slurry, the fluid level is lowered in the tank so that the load becomes live and the centre of gravity of the slurry load begins to constantly change. Accordingly, when drawing the tanker uphill or downhill or across slopes, the tanker can become extremely dangerous to operate as the load inside the tank has the potential to overturn the tanker and the drawing tractor.

Similarly, operators generally prefer to spread slurry in an uphill direction to ensure optimal emptying of the tanker i.e. as tankers discharge from the rear, uphill spreading causes the fluid to flow to the rear of the tanker to assist the emptying action. However, as a result, the load weight is directed onto and behind the wheels of the tanker thus significantly reducing the load weight on the wheels of the drawing tractor. Accordingly, traction at the driving wheels of the tractor is significantly reduced which can lead to dangerous situations where the tractor is unable to traverse an incline due to a lack of traction. In addition, where used, the additional weight of trailing shoes or dribble bars on the rear end of tankers can exacerbate the reduction in traction.

Attempts have been made to more evenly distribute load weight in tankers through the use of internal anti-surge baffles in the tank. However, anti-surge baffles on their own fail to address dangerously uneven weight distributions particularly on steep inclines. Accordingly, some known tankers are also provided with a partition towards the front of the tank which can extend partially downwards from the top of the tank to define partially separated front and rear slurry sections. Vacuum/air pressure pipes are connected to both sides of the partition but by way of a non-return valve system connected to the front section, the front section only ever receives vacuum but never air pressure. Accordingly, during filling the non-return valve is opened and vacuum is applied to both sides of the partition so that the tanker fills as one unit while, when emptying, the non-return valve is closed and air pressure is applied to the rear section only so that the rear section empties first until the remaining fluid level drops to the end of the partition and the air pressure being applied can then enter the front section and the fluid in the front section therefore empties into the rear section and gets discharged through the spreading outlet.

However, this arrangement suffers from the disadvantage that, when the front section begins to empty, the air that displaces the fluid comes from behind and under the partition in a bubbling action which can cause excessive froth which in turn can seriously restrict how full the tanker can be filled with succeeding loads i.e. the froth can cause a false full reading. Moreover, if the non-return valve fails or remains open, the tanker, unknown to the operator, empties in the same manner as a conventional tanker with the associated risk of the tanker tipping on inclined surfaces.

An object of the invention is to overcome at least some of the problems of the prior art.

Summary of the Invention

According to the invention there is provided a fluid tanker for transporting fluids comprising:

a tank for containing fluid having a front end and a rear end and at least one ballast chamber fluidly communicable with the tank for stabilising the tanker.

Preferably, the ballast chamber is fluidly separated from but communicable with the tank. More preferably, the ballast chamber is fluidly separated from the tank with bulkhead-like walls in the tank.

Advantageously, the ballast chamber is disposed towards the front end of the tank so that the tanker comprises a front ballast chamber and a rear chamber. More preferably, the ballast chamber is contained within the tank towards the front end of the tank.

Suitably, the front ballast chamber is fluidly communicable with the rear chamber via a conduit from the front ballast chamber. Preferably, the conduit comprises at least one connecting pipe in at least one bulkhead-like wall. More preferably, the connecting pipe extends downwards from the top or towards the top of the bulkheadlike wall into the rear chamber.

Optionally, the fluid tanker comprises an intermediate ballast chamber or

intermediate ballast chambers between the front ballast chamber and the rear chamber. Preferably, each intermediate ballast chamber is fluidly communicable with its adjacent chamber via a connecting pipe.

Preferably, the front ballast chamber comprises a fluid inlet/outlet. More preferably, the fluid inlet/outlet comprises an inlet/outlet pipe. Most preferably, the fluid inlet/outlet pipe extends generally rearwardly from the front ballast chamber towards the tank rear end.

Alternatively, the front ballast chamber comprises a separate fluid inlet and outlet. More preferably, the fluid outlet comprises a pipe. Most preferably, the fluid outlet pipe extends generally rearwardly from the front ballast chamber towards the tank rear end.

Preferably, the tanker comprises a vacuum/pressure pump inlet. More preferably, the vacuum/pressure pump inlet is in the rear chamber.

In preferred embodiment of the invention the fluid tanker comprises a drawn fluid tanker with a drawbar at the front end of the tank. Preferably, the fluid tanker comprises a slurry tanker.

The tanker of the invention is therefore completely divided by bulkhead-like dividers or walls into two or more separate chambers, at least one of which serves as a ballast chamber, which are linked by connecting conduits or pipes which enable fluid to flow through from low level on one side of the dividers to high level on the other side of the dividers. The tanker of the invention is both filled and emptied from the front ballast chamber through a generally rearwardly extending pipe from the front ballast chamber.

The necessary vacuum/pressure is applied through the rearmost chamber so that, during filling, the vacuum is turned on at the rearmost chamber and fluid is drawn into the front most ballast chamber first. Once the front ballast chamber is full to its top, the fluid flows/spills down its connecting pipe into the bottom of the next adjacent chamber and this process continues throughout all chambers until finally the last chamber is full and the vacuum is shut off. Conversely, during an emptying process, pressure is applied to the rearmost chamber which forces the fluid into the subsequent adjacent chambers through the connecting pipes until forced out through the discharge outlet at the front ballast chamber. In the tanker of the invention, fluid can flow through the tanker in an uninterrupted manner without the use of valves and with no frothing or bubbling. The absence of valves to control flow ensures that the tanker cannot fail when filling or emptying - filling and emptying occurs in a sequential manner in accordance with the

configuration of the ballast tanks in the tanker. Fluid load weight is maintained towards the front of the tanker when emptying to direct the load weight towards the wheels of a vehicle drawing the tanker for as long as possible during an emptying operation thereby optimising drawing vehicle traction. The self-contained isolated chambers within the tank of the tanker also ensure optimal gravitational stability of the tanker on inclined and uneven surfaces.

Brief Description of the Drawings

The invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a side view of a tanker of the invention in the form of a slurry tanker in which the cylindrical tank of the slurry tanker houses a slurry reservoir containing a front slurry ballast tank or chamber to contain the slurry within the ballast chamber as low to the tanker axle as possible (i.e. as close to the ground as possible), the ballast chamber being fluidly connected to a rear slurry chamber by a connecting pipe with the wheelset of the slurry tanker removed for clarity;

Figure 2 is an end view from the rear wall end of the slurry tanker of Figure 1 on a sloped surface having an incline, a, of 30° with the slurry within the ballast chamber being contained by the ballast chamber to maintain in excess of 75% of the slurry load inside the centre of gravity indicated by the broken line extending from the outermost part of the wheel located on the low side of the sloped surface;

Figure 3 is an end view from the rear wall end of a conventional slurry tanker without a ballast chamber in the same position as the slurry tanker of Figure 2 with the result that almost 40% of the slurry in the tanker is over the centre of gravity increasing the tipping risk;

Figure 4 is a side view of a second embodiment of a slurry tanker of the invention provided with additional first and second self-contained intermediate ballast tanks or chambers between the front ballast chamber and rear chamber, all chambers being fluidly connected in sequence by connecting pipes with the direction of fluid flow during a filling operation being indicated by the arrows; Figure 5 is a side view of the slurry tanker of Figure 4 with the direction of fluid flow during an emptying or spreading operation being indicated by arrows, and

Figure 6 is an end view from the rear wall end of a third embodiment of the slurry tanker similar to the slurry tanker of Figure 1 but in which the cylindrical tank of the slurry tanker is additionally positioned closer to the ground on the slurry tanker axle to further reduce the amount of slurry passing the centre of gravity (with the slurry tanker also being positioned on a sloped surface having an incline, a, of 30°) to maintain 84% of the slurry load inside the centre of gravity indicated by the broken line extending from the outermost part of the wheel located on the low side of sloped surface.

Detailed Description of the invention As shown in Figures 1 and 2 of the drawings, a first embodiment of a slurry tanker in accordance with the invention is generally indicated by the reference numeral 1 and is made up of a substantially cylindrical tank 2 fitted with a drawbar 3 for drawing the slurry tanker 1 with a vehicle such as a tractor (not shown). The cylindrical tank 2 has a circular front end wall 4, a circular rear end wall 5 and a sidewall 6 extending between the front end wall 4 and the rear end wall 5. Internally, the cylindrical tank 2 has a top substantially half-cylinder portion 7 and a lower bottom substantially half- cylinder portion 8 which together define a slurry reservoir 9.

The slurry reservoir 9 is sub-divided into a front self-contained slurry ballast tank or chamber 10 (hereinafter referred to as a chamber) towards the front end wall 4 and a rear self-contained slurry chamber 11 towards the rear end wall 5. As shall be explained more fully below, the ballast chamber 10 serves to contain slurry towards the front end of the slurry tanker 1 and therefore keeps the weight of the fluid in the reservoir 9 towards the front of the cylindrical tank 2 while emptying thus keeping the weight of that fluid on the wheels of a drawing vehicle for as long as possible to enhance vehicle traction. Accordingly, the task of spreading slurry is simplified and made safer as operators are less likely to be exposed to dangerous situations in which the drawing vehicle has little or no traction.

The self-contained ballast chamber 10 is substantially half-cylindrical in shape and is formed by bulkheads in the cylindrical tank 2 in the form of a half-cylindrical portion 4a of the front end wall 4, a transverse dividing top wall 12 extending between the sidewall 6, a portion 6a of the sidewall 6 and an upright dividing wall 13 extending upwards from the sidewall 4. The self-contained ballast chamber 10 is an enclosed tank defined by its bulkhead walls 4a, 12, 6a and 13 having a fluid conduit in the form of a connecting pipe 14 extending generally rearwardly from the upright dividing wall 13 adjacent the top wall 12 in a downwards direction into the rear chamber 11 to fluidly connect the ballast chamber 10 to the rear chamber 11. The connecting pipe 14 terminates at an open end 15. Two or more connecting pipes 14 can be employed if desired.

The rear chamber 11 is provided with an air pump inlet 16 for connecting the tank 2 to a pump (not shown) for filling and emptying operations. The air pump inlet 16 is provided in the sidewall 6 at the top of the tank 2 adjacent the front wall 4 and is in fluid communication with the rear chamber 11. A ballast chamber dual function slurry inlet/outlet 17 is defined in the sidewall portion 6a of the ballast chamber 10 at the underside of the tank 2 and opens into a dual function slurry inlet/outlet pipe 18 which extends generally rearwardly from the tank 2. In order to fill the cylindrical tank 2, vacuum is applied by the pump (not shown) to the inlet 16 so that negative pressure is applied to the rear chamber 11 and ballast chamber 10 via the connecting pipe 14. Accordingly, slurry is therefore drawn or sucked into the ballast chamber 10 via the dual function inlet/outlet pipe 18 and the dual function slurry inlet/outlet 17 to first fill the ballast chamber 10. When the slurry level in the ballast chamber 0 reaches the connecting pipe 14, the slurry spills or flows naturally into the rear chamber 11 through the connecting pipe 14 to fill the rear chamber 11. Flow of the slurry from the ballast chamber 10 into the rear chamber 11 creates a syphoning effect which improves flow and enhances the filling process. The cylindrical tank 2 is emptied in a reverse process where pressure is applied by the pump to the inlet 16 so that the slurry is urged under pressure from the rear chamber 1 1 into the ballast chamber 10 via the connecting pipe 14. Slurry from the ballast chamber 10 is therefore discharged through the dual function inlet/outlet pipe 18 via the dual function slurry inlet/outlet 17 to exit the slurry tanker 1. The process is continued until all slurry from the rear chamber 11 is pumped into the ballast chamber 10 for discharge so that the ballast chamber 10 is the last chamber to be emptied.

The cylindrical tank 2 is therefore filled and emptied from the self-contained ballast chamber 10. In particular, the weight of the slurry is maintained towards the front of the tank during emptying to direct the weight if the slurry to the wheels of the drawing vehicle for improved traction, stability and safety.

Figure 2 shows an end view from the rear wall end of the slurry tanker 1 of Figure 1 on a sloped surface 23 having an incline, a, of 30°. The slurry tanker 1 is shown with its wheelset 10 having first and second wheels 20,21 mounted either side of an axle 22. As shown in the drawing, slurry within the ballast chamber 10 is completely contained by the ballast chamber 10 to maintain in excess of 75% of the slurry load inside the centre of gravity indicated by the broken line extending from the outermost part of the wheel 21 located on the low side of the sloped surface 23 i.e. only 24.5% of the slurry load passes the centre of gravity line of the slurry tanker 1. Moreover, as the ballast chamber 10 is a self-contained enclosed chamber 10, when full, slurry within the ballast chamber 10 is prevented from shifting and sloshing by the walls of the ballast chamber 10 so that the slurry within the ballast chamber 10 is a dead load during emptying operations. This dead load serves to stabilise the slurry tanker 1 during emptying operations by effectively functioning as ballast. Moreover, as the ballast chamber 10 is the last chamber to be emptied, the slurry tanker 1 is stabilised for as long as possible during emptying/spreading operations. In contradistinction, as shown in Figure 3, in a slurry tanker 1 having a conventional cylindrical tank 2 with no ballast chamber 0, almost 40% of the load in the cylindrical tank 2 is past the vertical centre of gravity line when the slurry tanker 1 is on a slope of 30° thereby compromising the stability of the slurry tanker 1. In addition, the slurry within the slurry tanker 1 is live so that movement of the slurry tanker on uneven ground and the like can cause the slurry to shift and move causing in excess of 40% to shift beyond the slurry tanker's tipping point causing the slurry tanker 1 to overturn. Figures 4 and 5 show a second embodiment of a slurry tanker 1 of the invention broadly similar to the slurry tanker 1 of Figures 1 and 2 but provided with additional first and second self-contained intermediate ballast chambers 24,25 respectively between the front ballast chamber 10 and rear chamber 11. Like numerals indicate like parts. The intermediate ballast chambers 24,25 serve to further stabilise the slurry tanker 1 by subdividing and containing slurry loads within the slurry tanker 1.

The cylindrical tank 2 of the slurry tanker 1 is provided with a front first ballast chamber 10 disposed towards the front end wall 4 of the cylindrical tank 2. In the present embodiment, the first ballast chamber 10 is defined by a bulkhead-like first upright dividing wall 13, the front end wall 4 and the sidewall 6 of the cylindrical tank 2 and is provided with a downwardly depending connecting pipe 14 extending downwards from the upright dividing wall 13 from adjacent the top of the cylindrical tank 2 into the first intermediate ballast tank 24. The first ballast chamber 10 is also provided with a front inlet/outlet 17 and generally rearwardly extending inlet/outlet pipe 18 as previously described.

The first intermediate ballast chamber 24 is defined by the bulkhead like first upright dividing wall 13, a second upright dividing wall 13, a transverse dividing top wall 12 between the sidewall 6 and the sidewall 6 and is also provided with a downwardly depending connecting pipe 26 extending downwards from the second upright dividing wall 13 from adjacent the top wall 12 into the second intermediate ballast chamber 25. The-second intermediate ballast chamber 25 is larger in size than the first intermediate ballast chamber 24 and is defined by the cylindrical tank sidewall 6, the top wall 12 and second upright wall 13 of the first intermediate ballast tank 24 and a third upright wall 13 between the sidewall 6. The second intermediate ballast chamber 25 is also provided with a downwardly depending connecting pipe 27 extending downwards from the third upright dividing wall 13 from adjacent the top of the cylindrical tank 2 into the rear chamber 11. The rear chamber 11 is in turn defined by the third upright wall 13, the sidewall 6 and the rear end wall 6 of the cylindrical tank 2. The pump inlet 16 opens into the rear chamber 11 at the top of the cylindrical tank 2.

During filling, vacuum is applied to the pump inlet 16 to apply negative pressure throughout the cylindrical tank 2 i.e. in rear chamber 11 , the second intermediate ballast chamber 25, the first intermediate ballast chamber 24 and the front ballast chamber 10 through the connecting pipes 27,26,14. The negative pressure causes slurry to be drawn into the front ballast chamber 10 through the inlet/outlet pipe 18. When the slurry reaches its maximum level adjacent the connecting pipe 14 in the front ballast chamber 10 indicated by the reference numeral 28, the slurry flows/spills through the connecting pipe 14 into the first intermediate ballast chamber 24. The first intermediate chamber 24 is then filled until the slurry flows through its

connecting pipe 26 into the second intermediate ballast chamber 25. When the second intermediate ballast chamber 25 is filled, the slurry then flows through its connecting pipe 27 to fill the rear chamber 11. As indicated previously, the filling process is enhanced by a syphoning effect created once the front ballast chamber 10 has filled and the slurry commences flow into the first intermediate ballast chamber 24.

The slurry tanker 1 is emptied in a reverse process i.e. pressure is applied through the pump inlet 16 which forces the slurry first from the rear chamber 1 into the second intermediate ballast tank 25, the first intermediate ballast tank 24 and the front ballast tank 10 in sequence to exit the slurry tanker via the inlet/outlet pipe 18. Accordingly, the chambers of the slurry tanker 1 empty in a rear to front chamber sequence. Again, the process is enhanced by a syphoning effect as the inlet/outlet pipe 8 is at the lowest point on the slurry tanker.

Figure 6 shows a further embodiment of the invention broadly similar to the above embodiments but in which the cylindrical tank 2 of the slurry tanker 1 is additionally positioned closer to the ground to further reduce the amount of slurry passing the centre of gravity. The distinct and separate nature of the ballast chambers 0,24,25 and the rear chamber 11 facilitates the positioning of the slurry tanker axle 22 between two of the separate chambers 10,24,25,11 as desired to lower the cylindrical tank 2 without compromising fluid flow between the chambers 10,24,25,11 in the connecting pipes 14,26,27 whereas in prior art slurry tankers with lowered tanks the axle housing penetrating the tank can hinder fluid flow through the tank. For example, in this embodiment, by lowering cylindrical tank 2 by 30 cm as compared with the slurry tanker 1 of Figure 2, 84% of the slurry load was maintained inside the centre of gravity indicated by the broken line extending from the outermost part of the wheel 21 located on the low side of the sloped surface. Accordingly, the ballast chambers 10,24,25 and principally the front ballast chamber 10 serve to maintain the weight of fluids inside the tank 2 towards the front of the tank 2 as much as possible while emptying thus keeping the weight of the fluid on the wheels of the drawing vehicle for as long as possible thus helping the traction and stability of the drawing vehicle. The ballast chambers 10,24,25 also contain and restrain the fluid within the chambers 10,24,25 so that the fluid loads within the ballast chambers 10,24,25 are dead loads and do not shift thereby minimising the risk of tipping the slurry tanker in use particularly on uneven or sloped surfaces. Accordingly, the task of spreading fluids such as slurry with the slurry tanker 1 of the invention is much more user friendly and safer as operators are much less likely to encounter danger as a result of reduced traction or tipping.

In addition, the tanker 1 of the invention employs a natural syphoning action assisted by vacuum when filling and air pressure and syphoning when emptying to optimise filling and emptying.

As shown in Figures 4 and 5, if desired, the front ballast chamber 10 can be provided with a dedicated filling port 29 for filling the slurry tanker 1 through the filling port 29 instead of through the dual function inlet/outlet pipe 18.

Claims

1. A fluid tanker for transporting fluids comprising:

a tank for containing fluid having a front end and a rear end and

at least one ballast chamber fluidly communicable with the tank for stabilising the tanker.

2. A fluid tanker as claimed in Claim 1 wherein the ballast chamber is fluidly separated from but communicable with the tank.

3. A fluid tanker as claimed in Claim 1 or Claim 2 wherein the ballast chamber is fluidly separated from the tank with bulkhead-like walls in the tank.

4. A fluid tanker as claimed in Claim 3 wherein the ballast chamber is disposed towards the front end of the tank so that the tanker comprises a front ballast chamber and a rear chamber.

5. A fluid tanker as claimed in Claim 4 wherein the ballast chamber is contained within the tank towards the front end of the tank.

6. A fluid tanker as claimed in Claim 4 or Claim 5 wherein the front ballast chamber is fluidly communicable with the rear chamber via a conduit from the front ballast chamber.

7. A fluid tanker as claimed in Claim 6 wherein the conduit comprises at least one connecting pipe in at least one bulkhead-like wall.

8. A fluid tanker as claimed in Claim 7 wherein the connecting pipe extends downwards from towards the top of the bulkhead-like wall into the rear chamber.

9. A fluid tanker as claimed in any of Claims 1 to 8 wherein the fluid tanker comprises an intermediate ballast chamber between the front ballast chamber and the rear chamber.

10. A fluid tanker as claimed in any of Claims 9 wherein the fluid tanker comprises intermediate ballast chambers between the front ballast chamber and the rear chamber.

11. A fluid tanker as claimed in Claim 9 or 10 wherein each intermediate ballast chamber is fluidly communicable with its adjacent chamber via a connecting pipe.

12. A fluid tanker as claimed in any of Claims 4 to 11 wherein the front ballast chamber comprises a fluid inlet/outlet.

13. A fluid tanker as claimed in Claim 12 wherein the fluid inlet/outlet comprises an inlet/outlet pipe.

14. A fluid tanker as claimed in Claim 13 wherein the fluid inlet/outlet pipe extends generally rearwardly from the front ballast chamber towards the tank rear end.

15. A fluid tanker as claimed in any of Claims 4 to 14 wherein the front ballast chamber comprises a separate fluid inlet and outlet.

16. A fluid tanker as claimed in Claim 15 wherein the fluid outlet comprises a pipe.

17. A fluid tanker as claimed in Claim 16 wherein the fluid outlet pipe extends generally rearwardly from the front ballast chamber towards the tank rear end.

18. A fluid tanker as claimed in any of Claims 4 to 17 wherein the tanker comprises a vacuum/pressure pump inlet.

19. A fluid tanker as claimed in Claim 18 wherein the vacuum/pressure pump inlet is in the rear chamber.

20. A fluid tanker as claimed in any of Claims 1 to 19 wherein the fluid tanker comprises a drawn fluid tanker with a drawbar at the front end of the tank.

21. A fluid tanker as claimed in any of Claims 1 to 20 wherein the fluid tanker comprises a slurry tanker.