WO1996023108A1

WO1996023108A1 - A device for heating and transporting particulate material, such as sand or the like

Info

Publication number: WO1996023108A1
Application number: PCT/SE1996/000059
Authority: WO
Inventors: Gert NORDSTRÖM
Original assignee: Nordstroem Gert
Priority date: 1995-01-24
Filing date: 1996-01-23
Publication date: 1996-08-01
Also published as: CA2211407A1; SE503899C2; FI973100A; AU4593396A; SE9500226L; FI973100A0; SE9500226D0

Abstract

A device for heating and transporting particulate material, such as sand or the like, comprises a container (1) for the sand, an arrangement (2) for heating thereof and an arrangement (3) for transportation of the sand from the container to the delivery site (4). This is arranged to be located at a level above a lower part (5) of the container (1) to be able to deliver the sand transported by the transportation arrangement (3) to a load receiver (6), particularly a load vehicle, which can be positioned below the delivery site (4). The transportation arrangement (3) comprises an envelope (7) and transportation members arranged therein. The heating arrangement (2) is arranged to produce heated gas and deliver this one to a room within the envelope for heat transfer to the sand.

Description

A DEVICE FOR HEATING AND TRANSPORTING PAR¬ TICIPATE MATERIAL, SUCH AS SAND OR THE LIKE

FIELD OF THE INVENTION AND PRIOR ART

This invention relates to a device for heating and transporting particulate material, such as sand or the like, according to the introductory part of claim 1.

Primarily the invention is occupied with the problem of creating an effective slip protection for road ways, pavements etc cov¬ ered by ice and snow. It is well known per se that distribution of heated sand or the like gives the advantage that heated sand, in contact with ice or snow, gives rise to melting around the in¬ dividual grains of sand, whereafter these are frozen into place to be able to effectively carry out the intended slip protection function.

A device of the type initially mentioned is, for example, de¬ scribed in WO 93/14 270. There, the container is mounted on a vehicle, while the heating arrangement transports the sand to a region where heating takes place by means of the heating ar¬ rangement and, thereafter, the heated sand is spread upon the roadway in question by means of a suitable distribution ar¬ rangement. Even though this has not been possible to verify, it is fully possible that the known device functions very well in practice. However, the device suffers from the important disad¬ vantage that the costs should be discouragingly high. More precisely, every single sand distribution vehicle must be equipped with very expensive additional equipment.

Another known technique aims at heating the sand in particular distribution centres from which quite uncomplicatedly equipped vehicles collect the sand in and for distribution on the roads. By such a solution the individual vehicles only need to present a relatively cheap distribution equipment. The ordinary platforms of the vehicles may be used for sand receipt. A disadvantage of this solution is that handling at the distribution central tends to be quite ineffective. More precisely, one has hitherto loaded the sand to be heated into the interior of a generally horizontally orientated, drum, a burner having been disposed in or beside the drum and orientated so as to let the burner flame extend into the drum. The drum has been arranged in such a way that the heated sand has been transported out of one of the ends of the drum. The disadvantage of this solution is, above all, that the drum structure is bulky and expensive. Furthermore, it has been problematic to adapt the production of warm sand to the need. In practice, it has namely been necessary to forward a buffer portion of heated sand, and later on one has tried to store the sand by covering it with heat insulating carpets or the like until the sand has actually been needed. Thereby the sand has been moved to a relevant sand distribution vehicle by means of any suitable type of sand moving device, which in the ordinary case has had the character of a charging crane or a wheel mounted loader.

Further examples of prior art are shown in SE-B 462 623, US 1 363 369, US 3 940 120 and US 4 914 922.

THE OBJECT OF THE INVENTION

The object of the invention is to reduce the disadvantages dis- cussed above and to provide a device capable of making the 08 PCI7SE96/00059

loading of heated material onto a load receiver, particularly a load vehicle, possible in a rational and effective way.

SUMMARY OF THE INVENTION

The abovementioned object is fulfilled by providing the device according to the invention with the features defined in the char¬ acterizing part of claim 1. Thereby, a device capable of not only heating the material, but also delivering the heated material onto relevant load receivers, normally load vehicles, is ob¬ tained. As the material is heated while simultaneously being transported, an exact interadaption of heating and transporta¬ tion is obtained. Accordingly, it is always well heated material that will be delivered to the load receiver.

Advantageous developments of the solution according to the in¬ vention are defined in the dependent patent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring to the following drawings, a more detailed description of an embodiment of the invention, referred to by way of exam¬ ple, will follow hereinafter.

In the drawings:

Fig 1 is a schematic side view of the device according to the invention, a load receiver in the shape of a load vehicle being illustrated with broken lines,

Fig 2 is a view of the device of Fig 1 , as seen from above,

Fig 3 is a side view of a transportation screw included in the transportation arrangement, Fig 4 is a cross section along the line IV-IV in Fig 3,

Fig 5 is a cross section along the line V-V in Fig 3, and

Fig 6 is cross section along the line VI-VI in Fig 3.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Even though the device according to the invention also can be used for heating and transporting other particulate material, it will hereinafter be described with use of sand, more precisely sand intended for slip protection purposes.

The device comprises a sand container 1 , an arrangement 2 for heating the sand, and an arrangement 3 for transporting the sand from the container 1 to a delivery site 4. This is positioned as well as arranged to be positioned at a level above a lower part 5 of the container 1 to be able to deliver the sand trans¬ ported by the transportation arrangement 3 to a load receiver 6, particularly a load vehicle, which can be positioned below the delivery site 4. This load vehicle is supposed to be of a con¬ ventional type arranged for the purpose of distributing sand, namely equipped with a sand receiving load carrier and an equipment for distribution of the sand onto roadways and the like.

The transportation arrangement 3 comprises an envelop 7 and transportation members 9 arranged inside the latter, said mem¬ bers being further illustrated in Figs 3-6. The heating arrange- ment 2 is arranged to produce heated gas and deliver it to a room inside the envelop for heat transfer to the sand.

As can be seen in Fig 1 , the transportation arrangement 3 slopes upwards from the container 1 to the delivery site 4. In the preferred case, the transportation arrangement has a gen- 08 PCI7SE96/00059

erally linear extension. Furthermore, it is normally preferred that the transportation arrangement 3 starts off from a relatively low position adjacent to the container 1 , which position can in prac¬ tice be at or close to the ground surface.

The container 1 has the character of a sand receiving pocket. Suitably, the container 1 has a relatively important width at the top of it to be able to receive sand from suitable sand moving aids, such as shovel equipped loaders or charge cranes. In a downward direction the container suitably narrows and it com¬ municates with the interior of the envelop of the transportation arrangement 3 through an opening 10 in the lower part 5 of the container 1.

In the example it is illustrated how the device in total is sup¬ posed to be mobile. More precisely, this can be realized by providing the device with a set of wheels 11 and a traction ar¬ rangement 12, by means of which the device can be coupled to a suitable traction vehicle, and thereby act as a "trailer". Pref- erably, the traction arrangement 12, by for instance being pivo- tably connected to the frame 14 of the device at shafts 13, can be manoeuvred between an inactive position indicated by full lines in Fig 1 , and an active position indicated by broken lines in Fig 1. A locking means 15, e.g. in the shape of a bar, serves to reteasably lock the traction arrangement 12 in its active po¬ sition (see Fig 2). In the example, the traction arrangement 12 is orientated generally vertically (Fig 1) when in its inactive position, which puts the traction arrangement 12 out of way for the loading aids which are used for loading sand into the con- tainer 1.

The room 16 inside the envelop 7 is arranged to accommodate the transportation members 9 and receive the sand, whereby the heated gas and the sand gets into direct contact with each other. It is preferred that the heated gas is constituted by com- bustion gases. The heating arrangement 2 presents a chamber 17 from which heated gases are supposed to get transferred to the inner room 16 of the envelop 7 through another opening 18.

The camber 17 is a combustion chamber as it is co-ordinated with a burner 19, particularly an oil burner, which is mounted onto the chamber 17 in such a way that its flame is directed into the combustion chamber. In the example, the combustion chamber 17 is arranged above the envelop 7, so that combus- tion gases generated in the combustion chamber 17 will move downwards through the opening 18 and into the inner room of the envelop 7 and there move along the latter in a direction to¬ wards the upper end of the envelop 7, where the combustion gases are supposed to leave through a gas outlet 20.

The container 1 and the chamber 2 are arranged relatively close to each other at the lower part of the envelop 7. Thereby, the heated gas and sand will be in contact with each other in¬ side the envelop 7 along the main part of the length thereof, whereby a good heat transfer to the sand is assured.

As can be seen in Figs 3-6, the transportation members 9 com¬ prise a transportation screw localized inside the envelop 7. Suitably, the latter has a generally circular cross section which corresponds to the rotational volume of the screw, generated by the rotation thereof. The transportation screw 9 is driven by a suitable motor 21. Through a transmission 22, e.g. a chain transmission, this one is drivingly connected to an axle spindle 23 of the transportation screw.

The transportation screw 9 has different designs in three differ¬ ent regions, indicated by a, b and c in Figs 1 and 3. In all these regions a-c the transportation screw 9 however presents thread formations and a centre core 24. In region a, located in the vicinity of the opening 10 between the container 1 and the inner room 16 of the envelop 7, the trans¬ portation screw 9 has a thread formation which presents means 25 for disintegrating action upon aggregates of the sand and the like. As can be seen particularly in Fig 4, these integrating means 25 are constituted by thread portions which, as seen in the rotation direction of the transportation screw, are preceded by recesses 26. The consequence of this structure is that the thread formation of the screw 9 in the region a will present pro- jecting portions 25 which, by the rotation of the screw, will act in a mealing or disintegrating way upon the sand.

In region b, which in the example comprises the extension of the screw from the region of the opening 10 and on to the upper limitation of the opening 18 between the combustion chamber 17 and the inner room 16 of the envelop 7, the thread formation of the screw 9 likewise presents recesses 26 like the ones in region a, but the recesses in region b are less densely ar¬ ranged, which means that the screw 9 will have a higher degree of transporting function in region b than in region a, but on the other hand a lower degree of disintegrating function.

In a material heating region c, that is a region which is located upstream of or above the opening 18 between the combustion chamber 17 and the inner room 16 of the envelop 7, the screw 9 presents means 27 for executing an effect that entrains material in the cross wise direction of the transportation screw 9. More precisely, this effect is supposed to give rise to the sand being entrained around and above the core shaft 24 during the rota- tion of the screw, so that a good redistribution of the material is obtained, which in its turn implies good transfer of heat from the heated gas to the sand. In the preferred case, at a sufficiently high rotational speed of the screw 9, said entraining effect is supposed to lead to the sand being thrown upwards and that it will thus describe trajectories in the heated gas moving inside the envelop 7, which is particularly advantageous for the heat exchange sought for.

It is preferred that the entraining means 27 are constituted by pockets formed by parts 28 and 29 respectively of thread sec¬ tions arranged beside each other and cross pieces 30 over- bridging interspaces between these sections. Accordingly, these thread section parts 28, 29 are included in different thread lengths which overlap each other, and said parts are separated along the longitudinal axis of the screw 9 in the overlapping regions. In these overlapping regions the cross pieces 30 accordingly form bridges that close the space be¬ tween the thread lengths at least partly, but suitably fully, as in the illustrated example. In the latter, the cross pieces 13 are illustrated as comprised by flat plate or disc pieces, but it should be realized that the cross pieces also could be bent or bowl shaped.

The entraining means 27 are arranged in region c with suitable spaces, so as to obtain a good redistribution of the sand in this region.

At the upper parts of the envelop 7 there is a sand outlet 31 through which the sand can pass out of the envelop 7. An outlet connection piece 32 can join the outlet 31 , through which piece the sand can be deposited onto an underlying load receiver 6. In the example, the previously described gas outlet 20 is de¬ signed in the wall of the outlet connection piece 32 and another outlet connection piece 33 can be connected to the gas outlet 20.

To use the heat loss of the sand during the loading of sand onto the receiver 6, a cover tent 34 can be connected to the outlet connection piece 32, said tent being illustrated in two different positions in Fig 1. This cover tent 34 may have an edge portion of a sand entry opening, which portion is fixed to a peripherally outer edge portion 35 which extends around the mouth of the outlet connection piece 32.

During the use of the described device, one acts as follows: when the device has been brought into an operational condition according to Fig 1 , sand is loaded into the container 1. Thereaf¬ ter, the transportation arrangement 3 and the burner 19 are started, which means that the transportation screw 9 arranged inside the envelop 7 will successively transport the sand up¬ wards in the envelop 7, and heated combustion gases will at the same time reach into the envelop and flow upwards inside the latter. The heated sand is finally deposited onto the load re¬ ceiver 6. When this one has been filled up to a sufficient degree the action of the transportation screw 9 is stopped and the heating arrangement 2 is stopped, in practice by stopping the operation of the burner 19. If then no heated sand is required for a certain time, the device is kept inactive, apart from the fact that the heating arrangement 2 can be brought to operate in such an extent that the sand inside the envelop 7 of the trans¬ portation arrangement is kept at a certain minimum temperature which can be detected by means of temperature detectors ar¬ ranged at a suitable location. In the case of the burner 19, this one is operated intermittently so that during periods combustion gases will flow along the envelop 7 inside it while heating the sand. Accordingly this means that the arrangement is kept in continuous readiness to immediately be able to deliver ade¬ quately tempered sand as soon as an empty load receiver 6 is positioned under the delivery site 4 of the device. At a suitable disposition of the heating arrangement 2 in relation to the con¬ tainer 1 , e.g. adjacent to the latter, also a heating of the con¬ tainer 1 by means of the heating arrangement can be obtained, so that moisture containing sand in the container does not freeze. An alternative to readiness in the heating of the sand by means of a heating arrangement presenting a burner 19 is to arrange electrical heating elements, e.g. electrical heating cables of the type that automatically vary the delivered amount of heat in relation to the need of heat, so that the envelop 7 and the container 1 are heated in a required degree. Suitably the envelop and the container 1 are thereby insulated in and for re¬ duction of the heating need. A cap, a tarpaulin or the like can thereby be used to cover the loading opening of the container 1 at the top.

It is preferred that the container 1 , at its upper opening, is pro¬ vided with a sieve or a grid which, during loading of sand, sepa¬ rates possible, larger aggregates and makes these fall down onto the ground.

It is noted that the transportation screw 9 and its envelop 7 are to be designed in such a way in relation to each other that the heated gas can pass the screw inside the envelop. According to one possible embodiment, the transportation screw 9 can thereby be excentrically mounted in the envelop 7 to leave a sufficient area at the top for the heating gases.

It is noted that the throwing of sand which is caused by the ro¬ tation of the transportation screw 9 will tend to cool the envelop 7, particularly with reference to its upper portion, something which is important, particularly at burner heated embodiments where the heating gases can enter into the envelop with a tem¬ perature in the order of 1000°C.

When the described device is no longer needed at a certain place, it can be easily be moved as a trailer by bringing the traction arrangement 12 into an active operational condition and connect it to a suitable traction vehicle.

Of course the described device can be modified in a plurality of ways within the frame of the invention. For example, it should be mentioned that other heating arrangements than those based upon burners can come in question. For example, electrical heating elements can be used for heating air or other gas which is to be brought into motion inside the envelop of the transpor¬ tation arrangement together with the sand.

Claims

1. A device for heating and transporting particulate material, such as sand or the like, comprising a container (1) for the ma- terial, an arrangement (2) for heating the material and an ar¬ rangement (3) for transporting the material from the container to a delivery site (4), characterized in that the delivery site (4) is positioned or arranged to be positioned at a level above a lower part of the container (1) to be able to deliver the material trans- ported by the transportation arrangement (3) onto a load re¬ ceiver (6), particularly a load vehicle, which can be positioned below the delivery site, that the transportation arrangement (3) comprises an envelop (7) and transportation members (9) ar¬ ranged therein, and that the heating arrangement (2) is ar- ranged to produce a heated fluid and deliver this to a room (16) within the envelop for heat transfer to the material.

2. A device according to claim 1 , characterized in that the transportation arrangement (3) slopes upwards from the con- tainer (1) to the delivery site (4).

3. A device according to claim 1 or 2, characterized in that the container communicates with the envelop (7) of the transporta¬ tion arrangement through an opening (10) in the lower part of the container.

4. A device according to any of the preceding claims, charac¬ terized in that said room (16) within the envelop (7) is arranged to accommodate the transportation members (9) and receive the material, whereby the heated fluid and the material get into contact with each other.

5. A device according to any of the preceding claims, charac¬ terized in that the heated fluid is a gas, particularly combustion gases.

6. A device according to claim 5, characterized in that it com¬ prises a chamber (17) from which heated gases are intended to be transferred to the inner room of the envelop (7) through an- other opening (18).

7. A device according to claim 6, characterized in that the chamber (17) is a combustion chamber.

8. A device according to claim 6, characterized in that the container (1) and the chamber (17) are arranged relatively close to each other at the lower end of the envelop.

9. A device according to any of the preceding claims, charac- terized in that the envelop (7) presents a fluid outlet (20) at its upper end.

10. A device according to any of the preceding claims, charac¬ terized in that the transportation members (9) comprise a transportation screw.

11. A device according to claim 10, characterized in that the transportation screw (9) has a thread formation which at least in one region (a) in the vicinity of the opening (10) between the container and the inner room of the envelop presents means (25) for disintegrating action upon aggregates of material or the like.

12. A device according to claim 11 , characterized in that the disintegration means (25) are constituted by thread portions which, as seen in the rotational direction of the transportation screw, are preceded by recesses (26).

13. A device according to claim 10, 11 or 12, characterized in that the transportation screw (9), at least in a material heating region (c), presents means (27) for executing an effect which entrains the material in a crosswise direction of the transporta¬ tion screw.

14. A device according to claim 13, characterized in that the entraining means (27) are constituted by pockets formed by parts of thread sections arranged beside each other and cross pieces (30) bridging spaces between said sections.