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Title:
SYSTEM FOR PURIFYING ASPHALT FROM AN ASPHALT LAKE
Document Type and Number:
WIPO Patent Application WO/2014/209115
Kind Code:
A1
Abstract:
The present invention relates to a system for purifying asphalt from an asphalt lake. The system comprises for this purpose a slope on which asphalt tumbles downward in the direction of a sedimentation container. Provided at an end of this container, at a right angle to a wall of the container, are sieving walls through which liquid asphalt can be suctioned in. This asphalt is then sprayed onto the asphalt on the slope so that the melting process is improved.

Inventors:
PISO HERMAN BASTIAAN DIRK
Application Number:
PCT/NL2014/050416
Publication Date:
December 31, 2014
Filing Date:
June 24, 2014
Export Citation:
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Assignee:
PISO HERMAN BASTIAAN DIRK
International Classes:
B01D35/18; C10G31/09; B01D36/04; B01J8/00; B01J8/08; B01J8/12; B09C1/06; C10G1/02
Domestic Patent References:
WO2011059321A12011-05-19
Foreign References:
DE102010021239A12011-11-24
CA2051136C1999-01-05
GB714091A1954-08-25
Attorney, Agent or Firm:
JACOBS, Bart (P.O. Box 18558, EN The Hague, NL)
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Claims:
Claims

1. System for purifying asphalt from an asphalt lake, comprising:

a housing with a front wall, a rear wall, two side walls, a bottom and a roof provided at a front side thereof with an opening for depositing the asphalt therethrough;

wherein the housing comprises:

at least one sieve for sieving the deposited asphalt;

a slope inclining downward from the front wall in the direction of the rear wall, extending between the two side walls and placed at a distance therefrom;

heating elements which are placed on the slope for the purpose of heating the asphalt present on the slope;

a sedimentation container for collecting the asphalt falling from the slope, this sedimentation container being bounded on a front side by a closed wall and on sides by separating walls running parallel to the side walls and ending at a distance from the rear wall;

a pair of sieving walls placed in transverse direction between the side walls and the separating walls, and

a pair of closing walls for closing the space between the separating walls and the side walls on an upper side;

wherein the housing, the slope, the separating walls, the closed wall, the sieving walls and the closing walls together define a hollow space, wherein asphalt deposited onto the slope can only enter the hollow space by passing through the at least one sieve;

wherein the housing has an outflow opening for access to the hollow space and an inflow opening for feeding asphalt back onto the slope;

wherein the at least one sieve comprises a sieve incorporated in or forming part of the sieving wall;

the housing further comprising a spray installation for spraying the fed back asphalt onto the slope;

the system further comprising a pump device for suctioning in asphalt through the outflow opening and feeding back the suctioned asphalt through the inflow opening.

2. System as claimed in claim 1 , wherein the slope ends at and supports on and/or is connected to the closed wall.

3. System as claimed in claim 1, wherein the slope ends above or in the

sedimentation container.

4. System as claimed in any of the claims 1, 2, 3, wherein the closing walls extend substantially horizontally.

5. System as claimed in any of the foregoing claims, wherein the slope is raised on both sides and wherein the heating elements are placed in a lower, middle part of the slope.

6. System as claimed in claim 5, wherein an upper side of the closing walls connects at the position of the closed wall to the raised portion of the slope. 7. System as claimed in any of the foregoing claims, wherein the heating elements continue beyond the closed wall and into the sedimentation container.

8. System as claimed in any of the foregoing claims, wherein the heating elements comprise elongate tubes through which a heated thermal medium such as thermal oil is carried.

9. System as claimed in claim 5, wherein the at least one sieve comprises a sieve which forms part of an upper side of the raised portion.

10. System as claimed in any of the foregoing claims, wherein the sieve walls are disposed at an end of the separating walls.

11. System as claimed in any of the foregoing claims, wherein the at least one sieve comprises a sieve which is received in the separating walls at a part thereof lying close to the rear wall.

12. System as claimed in any of the foregoing claims, wherein the at least one sieve comprises openings of a maximum dimension of 20 mm.

13. System as claimed in any of the foregoing claims, wherein an angle of inclination of the slope lies between 5 and 21 degrees.

14. System as claimed in any of the foregoing claims, wherein the sieving wall has a width measured in transverse direction of between 0.2 and 0.5 m. 15. System as claimed in any of the foregoing claims, wherein the height of the closed wall lies between 0.5 and 1.5 m.

16. System as claimed in any of the foregoing claims, wherein the spray installation comprises a duct extending between the side walls and comprising spray openings facing toward the slope.

17. System as claimed in claim 16, wherein a maximum dimension of the spray openings lies between 10 and 100 mm.

18. System as claimed in any of the foregoing claims, wherein the housing is a concrete structure.

19. System as claimed in any of the claims 1-17, wherein the housing is a sea container. 20. System as claimed in claim 19, wherein the rear wall is provided with a closable opening, such as a door, for the purpose of providing access to the sedimentation container.

21. System as claimed in any of the foregoing claims, wherein heating elements are placed on the bottom of the housing for the purpose of heating asphalt in the hollow space.

Description:
System for purifying asphalt from an asphalt lake

The present invention relates to a system for purifying asphalt from an asphalt lake.

During the Second World War, oil distillation was mainly focussed on obtaining oil for the aviation industry. Other products released during fractional distillation, such as asphalt, were seen at the time as useless byproducts. As a result, there are numerous dumping sites worldwide where asphalt has for instance been dumped in a lake. An example hereof is the asphalt lake on the Netherlands Antilles.

Because oil reserves are becoming ever scarcer, resulting in a rising oil price, interest in purifying the asphalt in the asphalt dumping sites is increasing. To purify asphalt it has to be heated in order to increase the fluidity. The temperatures necessary here lie above 100 degrees Celsius.

An as yet unsolved problem is related to the explosive character during heating of the contaminated asphalt. A cause of this behaviour is the moisture retained in the asphalt. At high temperatures this moisture cannot expand sufficiently, whereby enormous pressures can build up in the asphalt.

The present invention provides a solution to the above stated problem. The invention provides for this purpose a system for purifying asphalt from an asphalt lake comprising a housing with a front wall, a rear wall, two side walls, a bottom and a roof provided at a front side thereof with an opening for depositing the asphalt therethrough.

The housing comprises at least one sieve for sieving the deposited asphalt and a slope inclining downward from the front wall in the direction of the rear wall, extending between the two side walls and placed at a distance therefrom. The asphalt for purifying is here deposited through the opening in the roof and onto the slope. Further present in the housing are heating elements which are placed on the slope for the purpose of heating the asphalt present on the slope. The housing also comprises a sedimentation container for collecting the asphalt falling from the slope. The sedimentation container is bounded here on a front side by a closed wall and on sides by separating walls running parallel to the side walls and ending at a distance from the rear wall. Sedimentation takes place in the sedimentation container, wherein the large contaminants such as stones and branches can precipitate in the container.

The housing also comprises a pair of sieving walls placed in transverse direction between the side walls and the separating walls, and a pair of closing walls for closing the space between the separating walls and the side walls on an upper side. The housing, the slope, the separating walls, the closed wall, the sieving walls and the closing walls here together define a hollow space. Asphalt deposited onto the slope can only enter the hollow space by passing through the at least one sieve.

The housing further has an outflow opening for access to the hollow space and an inflow opening for feeding asphalt back onto the slope.

The at least one sieve comprises a sieve incorporated in or forming part of the sieving wall. The housing also comprises a spray installation for spraying the fed back asphalt onto the slope. The system comprises for this purpose a pump device for suctioning in asphalt through the outflow opening and feeding back the suctioned asphalt through the inflow opening.

An important aspect of the present invention is the division of the space in the housing into a hollow part and another part, wherein asphalt is deposited into the other part and can only reach the hollow part by being sieved.

The placing of the sieve is according to the invention not random. This is because it has been found that if the sieve is positioned incorrectly it can easily become blocked by the contaminants in the asphalt. According to the invention the sieving wall, in which a sieve is incorporated, is therefore placed at a distance from the closed wall. This latter wall is the starting point of the sedimentation container. The sieving wall is therefore placed at the end of the sedimentation container, substantially parallel to the rear wall of the housing.

Asphalt which is deposited onto the slope is continuously heated. If sufficient liquid asphalt has been generated, hot asphalt is also sprayed onto the deposited asphalt. The angle of inclination of the slope will cause the deposited asphalt to tumble. The combination of the tumbling movement and the heating of the deposited asphalt, as well as the spraying of liquid asphalt over the asphalt on the slope, ensures that the risk of explosions caused by excessive pressure build-up in the asphalt can be avoided.

Because the sieving wall is placed at the end of the sedimentation container the contaminants in the asphalt have enough time to precipitate. The placing of the sieving wall parallel to the rear wall provides the particular advantage that the chance of blockage of the sieving wall by these contaminants is reduced. According to the invention heating thus takes place first, then sedimentation, and finally a sieving action. This does not otherwise preclude sieves also being utilized at other positions. The sieving wall is however particularly crucial at the start of the process, when the deposited asphalt is still relatively cold. It is precisely during this stage that it is important to be able to guarantee that the sieving action is not lost due to blockage.

The slope can end at and support on and/or be connected to the closed wall. The term closed wall refers here to the fact that this wall has in principle no sieving action. The closed wall can however be provided with a sieve. This will however become easily blocked by the sedimentation during use, giving the wall a closed character.

The slope can consist of one or more plates ending at the closed wall. The wall is here placed in the housing as a transverse partition.

The slope can however also end above or in the sedimentation container. There can also be a space between the closed wall and the slope. This opening however has to be placed such that no unsieved asphalt enters into the hollow space from the sedimentation container during the purifying process. The closed wall is preferably connected to the slope, and the only openings in the sedimentation container to the hollow space are the openings of the sieve.

The closing walls preferably extend substantially horizontally. The slope can also be raised on both sides, wherein the heating elements are placed in a lower, middle part of the slope. An upper side of the closing walls can further connect at the position of the closed wall to the raised portion of the slope.

It is thus possible that a wide channel is formed which is bounded on either side by the raised portions. This channel can continue to a position beyond the closed wall. In this case, the raised portion will transpose into a closing wall. The height of the raised portion can be adjusted to the height of the heating elements, such that the upper side of heating elements lies at the same height as the raised portions. It is then further recommended for the at least one sieve to comprise a sieve forming part of an upper side of the raised portion and/or closing wall. A sieving edge can hereby be formed which continues from the front wall as fas as the rear wall, but preferably not touching this.

The heating elements can continue beyond the closed wall and into the sedimentation container. The asphalt hereby also remains heated in the sedimentation container. The liquid asphalt will here separate from the contaminants and flow toward the rear wall, where it will bend sideways and will flow through the sieving wall in the direction of the front wall. This effect is also aimed at in the absence of heating in the sedimentation container.

The heating elements can comprise elongate tubes through which a heated thermal medium such as thermal oil is carried.

The sieving walls are preferably disposed at an end of the separating walls. Hereby, the asphalt need not first flow back in the direction of the front wall before being sieved.

It is otherwise possible for the at least one sieve to comprise a sieve which is received in the separating walls at a part thereof lying close to the rear wall. This enables liquid asphalt to be directly sieved sideways in the sedimentation container, this in addition to the sieving action of the sieving walls.

The at least one sieve preferably comprises openings of a maximum dimension of 20 mm. An angle of inclination of the slope lies here between 5 and 21 degi ees and/or the sieving wall has a width measured in transverse direction of between 0.2 and 0.5 m.

The height of the closed wall further lies between 0.5 and 1.5 m, and the rear wall lies about 0.3 m from the sieving wall.

The spray installation comprises for instance a duct extending between the side walls and comprising spray openings facing toward the slope. These openings for instance have a maximum dimension of between 10 and 100 mm. The housing can be embodied as concrete structure. The whole structure can hereby be buried. It is however also possible to embody the housing as sea container. The system is hereby made mobile, and it can be easily displaced between processing locations without the need for for instance foundation work.

A sea container has well-defined dimensions, such as a length of 12.2 m, a width of 2.4 m and a height of 2.9 m. Using a sea container has the further advantage that a closable opening, such as a door, can be provided in simple manner for the purpose of providing access to the sedimentation container. This enables a user to remove sediment from the sedimentation container.

Heating elements can further be placed on the bottom of the housing for the purpose of heating asphalt in the hollow space.

The invention will be discussed in more detail hereinbelow, wherein Figure 1 shows a partially cut-away view of an embodiment of the system according to the invention.

Figure 1 shows a system 1 comprising a housing 2 in the form of a sea container. Further provided is a pump device 3 for feeding back asphalt.

The walls of housing 2 are shown partially in broken lines for the sake of clarity. Provided in the roof of housing 2 is an opening 4 through which the asphalt for cleaning can be deposited. The asphalt falls here onto a slope 5 running from a front wall 6 of housing 2 downward in the direction of rear wall 7.

Slope 5 is raised on either side, a middle part 8 hereby lying at a lower position than raised portions 9. Raised portions 9 can be provided on the upper side with a sieve.

Placed on slope 5 are heating elements 10 which preferably lie with their upper side roughly level with the upper side of raised portions 9.

Slope 5 rests on a closed wall 11. Together with separating walls 12, this wall forms a sedimentation container 13. Separating walls 12 are here disposed parallel to side walls 14 of housing 2. Horizontally extending closing walls 15 seal the space between separating walls 12 and housing 2 on the upper side. Provided on a side facing toward rear wall 7 are sieving walls 16 which ran parallel to rear wall 7 but are placed at a distance therefrom. Rear wall 7 further comprises a door 17 through which sedimentation container 13 can be cleaned.

Heating elements 10 continue horizontally into sedimentation container 13.

Housing 2, slope 5, separating walls 12, closed wall 11, sieving walls 16 and closing walls

15 together define a hollow space, wherein asphalt 18 deposited onto the slope can only enter into the hollow space by passing through a sieve. It is noted here that sieving walls 16 play an important part because they run the least risk of becoming blocked, since they are placed at a distance from the position where contamination will precipitate. This is partly due to the fact that sieving walls 16 are positioned at a right angle to separating walls 12.

A sieve can be provided in the upper side of raised portions 9. A sieve can also be provided on the rear side of separ ating walls 12.

The particular placing of sieving walls 16 enables sufficient liquid asphalt to reach the hollow space, also in the case of recently deposited asphalt. This is important because the liquid asphalt plays an important part in the further process, as will be elucidated below.

Side wall 14 comprises an opening 19 for discharging liquid asphalt from the hollow space. This asphalt is suctioned in by pump device 3 and fed back through conduits 20, 21 into housing 2 via an opening 22. Housing 2 comprises for this purpose a spray installation 23 with openings through which liquid asphalt is sprayed onto slope 5 and the asphalt 18 present thereon. Opening 19 can also be connected to a distributing valve 24 through which purified asphalt can be discharged via a conduit 25. Heating elements 26 can be placed on the bottom of housing 2 for the purpose of holding the asphalt in the hollow space at temperature.

During an initial depositing of asphalt, this asphalt will tumble downward in the direction of sedimentation container 1 while being heated. When sufficiently filled with asphalt, a liquid fraction of the asphalt which reaches sedimentation container 13 via sieving walls 16 will be suctioned in by pump device 3 and sprayed onto asphalt 18 on slope 5 by spray installation 23. This facilitates the melting of asphalt 18 in that moisture accumulations in asphalt 18 can be broken up, resulting in less chance of explosive situations. At a given moment an equilibrium will be achieved, with the net result that the same quantity of contaminated asphalt is deposited through opening 4 as the quantity of purified asphalt which is discharged through conduct 25 via opening 19.

It will be apparent to the skilled person that various modifications can be made to the embodiment shown here without departing from the scope of protection as defined by the appended claims.