Bitumen cistern with fast discharge.

The present invention relates to tanks, commonly called bitu-to-container, for transporting bitumen from the storage location to the location where it is desired to use, which include a reheater for heating the bitumen to a temperature sufficient for transplant, it is to say the emptying of the tank.

Two main types of bitu-to-containers are known from prior art.

The first type (I) consists of a tank of substantially parallelepiped shape having a bottom on which there is a floor, and a heating device between the bottom and the floor, the heater thereby heating the floor on which is stored the bitumen to 1' temperature sufficient to cause.

This type of bitu-to-container exhibits the disadvantage of heating the bitumen too slowly. For causing a class 50/70 bitumen (widely used, especially in Africa) and for a starting point temperature of 42 °c (ambient temperature in Africa), it takes 24 hours with the bitu-to-container prior type floor heating to reach 100 °c, (100 °c being the temperature from which the depoting is possible).

The other type (type-II) known bitu-to-container consists of a tank substantially circular cylindrical shape, in which extends longitudinally and then perpendicularly to the top of the tank a heating pipe in which circulates hot air for causing the bitumen to the temperature dump.

The time required, from 43 °c, to reach the minimum temperature (100 °c) dump is shorter than in the other type of bitu-to-box (20 hours instead of 24 hours). However, this type of bitu-to-container exhibits several disadvantages, namely a higher center of gravity (due to the diameter of the tank), which is detrimental to the transportation on roads and paths hilly terrains and secondly in that the bitumen which is in the longitudinal portion of the pipe, at the dump valve is at too low a temperature to be dépoté, the depoting must thus be formed by means complex auxiliary.

The present invention aims a bitu-to-box that allows a faster depoting bitumen after transportation through a heater simply not influencing, by its complexity or weight, the physical characteristics of the bitu-to-container and bitumen, i.e. maintains a low center of gravity for the bitu-to-box, a volume large bitumen transported and heatable denature and without the loss of free or reduced asphalt-dépotable (unlike bitu-to-box of the second type).

A first pipe with a hot air heating is substantially in contact by its entire outer side surface with the bitumen contained in the tank. The first pipe comprises at least one U-shaped horizontal section, whose branch innermost communicates with the inlet of the pipe and the closest outside with the pipe outlet.

Thus providing a U-shaped horizontal section primarily powered by its inner limb, heating is achieved faster and more homogeneous the bitumen contained in the tank, while ensuring a low center of gravity bitu-to-box, thereby facilitating its transportation.

This type of bitu-to-container is disclosed in United States patents US-3804079 and US-to-3718131.

According to the invention, there is provided at least one second tube having a U-shaped section disposed horizontally, the air inlets and the first and second heat pipes being arranged so that the hot air flows in the two branches the innermost of the two U-shaped sections are opposite to one another.

This is achieved by heat transfer to the bitumen and thus heating the bitumen, particularly good and homogeneous, with a time to reach the 130 °c (temperature ideal depoting) which is only 16 hours while it takes 24 hours with the tanks known.

According to an advantageous embodiment, the two U-shaped sections are disposed in a same horizontal plane, preferably into the bottom of the tank.

This allows a high stability of the tank, which is useful in particular for transportation on roads in accidents.

According to a still further advantageous embodiment, the tank is of parallelepiped shape, thereby further its stability during transportation. With respect to bitu-to-bulk containers of prior cuboid (floor heating), is allowed to heat faster a larger amount of bitumen.

Is now describes one résalisation of the invention given solely by way of example, by referring to the drawing in which:

figure 1 is a view in elevation of a bitu-to-box according to the invention,

figure 2 is a top view of the bitu-to-box of Figure 1,

figure 3 is a view of a detail of the bitu-to-box of Figures 1 and 2.

The tank 1 of parallelepipedal shape is for containing bitumen during transportation from one storage location to a location where it is desired to be following the dépoté by a valve (not shown) dump.

Inside the tank 1, extends a first pipe 2, 3 a first inlet to a first outlet 4.

A second pipe 5 extends into the tank 7 1 a second inlet to a second outlet 8.

The first pipe includes a first horizontal section extending U-shaped, and a second vertical section extending from the end of the first section to the first discharge 4. The vertical section is much shorter than the horizontal portion so that the center of gravity remains low. The length of the horizontal section and the direction in which it is traversed by the hot air provide heating efficiency.

Similarly, the second pipe comprises a first U-shaped horizontal section and a second vertical section extending from the end of the first section to the second outlet 8.

Devices for producing heated air, for example burners 9 are arranged to be connected to the inputs 3 and 7 to produce hot air which enter the pipes 2 and 5 for heating the bitumen contained in the tank 1.

The two U-shaped sections are disposed in a same horizontal plane, the bottom of the tank.

The two inputs 3 and 7 are disposed opposite to each other so that the flows of air passing through each first U-leg of the first two sections U-flow in opposite directions.

For asphalt class 50/70, an ambient temperature of 42 °c, a temperature of the hot air to the inlet of 500 °c and an outlet temperature of 150 °c, it is possible to heat the bitumen to 100 °c in 9 hours, 20 hours for a against bitu-to-container type II and 24 hours for a bitu-to-box type I (floor heating).

According to a further development of the invention, there is provided from each of the inputs 3 and 7 and 11 on a first portion of each of the first branches of the U-section of the pipes 3 and 6 larger than on the rest of the pipe and a nozzle 12 entering the larger section of the pipe and to which is connected the burner 9. Protected thereby better the tank 1 at the inputs, which are subjected to high temperatures.