GB2342092A

GB2342092A - Tipping heated hopper for bituminous aggregate

Info

Publication number: GB2342092A
Application number: GB9821140A
Authority: GB
Inventors: Anthony Kujawa
Original assignee: Hanson Quarry Products Europe Ltd; ARC Ltd
Current assignee: Hanson Quarry Products Europe Ltd; ARC Ltd
Priority date: 1998-09-29
Filing date: 1998-09-29
Publication date: 2000-04-05
Anticipated expiration: 2018-09-29
Also published as: WO2000018667A1; AU5753399A; GB9821140D0; GB2342092B

Abstract

A tipping heated hopper comprises a hopper 4, having a filling opening 16 at a first end and a discharge outlet 28 at a second opposite end 12, a support structure for supporting the hopper 20, e.g. by a pivotal mounting to the second end of the hopper 24, and means, e.g. a number of hydraulic pistons 26 and hydraulic locking pins (38, Figure 3), acting between the hopper first end and the support structure for raising the hopper into a discharge position. Preferably the hopper is mounted in a thermally isolated manner, e.g. by using heat insulating spacers, on a subframe 19 and its temperature is controlled by the provision of double walls 18 containing a layer of insulating material and heating elements. Preferably, when the first end of the hopper is lowered, a lorry may be driven into the hopper through the filling opening to fill the hopper and also the hopper is mounted on a number of load cells for weighing the hopper. The hopper outlet may also be provided with a geared motor driven sliding gate (36, Figure 3) opening onto a screw conveyor (30, Figure 3) which delivers the bituminous aggregate to a belt conveyor (31, Figure 2) having a weighing device which controls the opening of the gate so as to dispense a desired weight of aggregate. The hopper may also be fitted with an internal hinged flap door (40, Figure 4), operated by an electric winch, which may be opened in a controlled manner to slow the fall of the aggregate to prevent the loss of bitumin from the aggregate upon elevation of the hopper.

Description

2342092 SELF RAISING HOPPER FOR DELIVERING AGGREGATE This invention

relates to a self raising hopper for delivering aggregate such as bituminous coated roadstone for the construction and repair of roads and pavements.

Bituminous coated roadstone is traditionally produced at either quarry sites or depots, which are often some distance from the market. The coated roadstone material is then delivered to the customer by heavy goods vehicle (HGV). These vehicles have insulated bodies and normally deliver a standard load to the customer of 16, 20, or 24 tonnes. The product has to be delivered to the customer within a given time due to heat loss during transit and the minimum is temperature required for laying the material. If the lorry is delayed on site the customer may be charged an additional cost of the waiting time for the vehicle.

If excess material has been ordered this will often be wasted.

Different solutions have been developed to try to overcome these problems through the use of satellite storage facilities for coated materials at strategic sites.

Some companies employ "hot boxes" that store coated roadstone materials. The hot box comprises a simple heated and insulated structure with doors that open at the front and lids that raise up, permitting coated materials to be delivered by lorry and reloaded by shovel. The main disadvantage with this design is the heat loss when the doors are opening and the need to use materials on a "last in first out" basis, which often results in wastage. A loading shovel is also required for loading vehicles and reloading the hot box.

Another design is raised hot storage bins. This is a larger structure which requires a hopper for the delivery lorry to discharge into and an elevator to raise the materials into the bins. Lorries collect the stored materials from under the heated and insulated bins. The major problems with this system are the high capital costs and the overall height of the structure.

According to a first aspect of the present invention there is provided a device for delivering aggregate, the device comprising:

a hopper having a filling opening for receiving aggregate at one end and an outlet for discharging aggregate at the opposite end; a support structure for supporting the hopper relative to the ground; and means acting between the hopper and the support is structure for raising the said one end of the hopper into a discharge position.

Preferably the hopper is movable from a loading position in which the filling opening is disposed a first horizontal distance and a first vertical distance from the outlet to the discharge position in which the filling opening is disposed a second horizontal distance and a second vertical distance from the outlet, said first horizontal distance being greater than the said second horizontal distance and the said first vertical distance being smaller than the said second vertical distance.

Preferably the said raising means comprises at least one hydraulic or pneumatic actuator pivotably connected to the hopper and the support structure.

Preferably the hopper is pivotably connected to the support structure at the said opposite end.

Preferably the hopper is fixed to a subframe to which the raising means is connected. It has been found by the inventor that considerable heat loss occurred due to heat loss f rom the hopper to the subframe, so means are provided to thermally isolate the hopper from the subframe. The isolation means preferably comprises heat insulating spacers interposed between the hopper and the subframe. The spacers may for example comprise Ferodo (registered trade mark) packers formed from asbestos free brake lining material.

Preferably the support structure comprises a concrete slab, the support structure may be adapted such that when the first end of the hopper is lowered, a lorry can be driven into the hopper through the filling opening.

Preferably the hopper is mounted on weight measuring means, such as load cells, so that the weight of the hopper can be determined.

Preferably a screw conveyor is provided adjacent the outlet from the hopper. The outlet is preferably closed by a sliding gate arrangement such as a sliding valve discharge door.

Preferably the aggregate is discharged onto a belt conveyor for loading into a customer's vehicle. An electric geared motor may be used to open and close the door and may operate in conjunction with a belt conveyor comprising a belt weigher to allow metered discharge of aggregate material from the hopper.

Preferably the filling opening is provided with a loading door. The loading door may be provided with a seal and is preferably insulated.

Preferably the hopper is provided with an internal door at an intermediate position along its length. The internal door may comprise a hinged flap which may be swung down from a wall of the hopper to partition the hopper and thereby reduce heat loss when the hopper is only partially full.

Although the aggregate may comprise construction material or agricultural aggregates such as lime, preferably it comprises paving material and more p--eferably comprises bituminous coated roadstone.

Preferably the hopper is insulated. This insulation may be in the form of double skinned panels which comprise the base and/or side walls. The insulation may comprise Rockwool (registered trade mark) and may be situated between the inner and outer skins of the hopper. The hopper may also be heated, for example by means of gas burners or electrical elements. Thermostatically controlled electrical elements may be situated between the inner and outer skins of the hopper.

According to a second aspect of the present invention, there is provided a method of filling a hopper with aggregate, the method comprising the steps of:

(a) partially filling the hopper with aggregate through a filling opening in an end of the hopper, with the hopper in a filling position; (b) rotating the hopper about the end of the hopper opposite to the filling opening, such that the aggregate in the hopper falls under gravity towards said opposite end; (c) rotating the hopper back to the filling position; (d) putting additional aggregate into the hopper; and (e) repeating steps (b) to (d) until the hopper is full.

Preferably the method further comprises the steps of:

(f) rotating the hopper about the said opposite end of the hopper; (g) locking the hopper in the raised position; and (h) discharging metered quantities of aggregate from an outlet in the said opposite end of the hopper.

For a better understanding of the present invention and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which:

Figure 1 shows a tipper lorry tipping aggregate into a hopper; Figure 2 is an end view of the hopper of Figure 1 in the raised or aggregate discharge position; Figure 3 is a side view of the hopper of Figure 1 in the raised or aggregate discharge position; and Figure 4 shows a pivoting internal door provided in the hopper.

Referring to the drawings, Figure 1 shows a conventional tipper lorry 2 tipping heated paving materials such as bituminous coated roadstone (i.e.

asphalt or tarmacadam) into a hopper 4. The hopper 4 comprises a base 6, two side walls 8, 10, an end wall 12 and a top wall 14. An opening 16 is bordered by the base 6, side walls 8, 10 and top wall 14. A hydraulically operated door 18 extends over the opening 16 and is pivotably connected to an end of the top wall 14.

The base 6 rests on a subframe 19 which is fixed to a concrete base pad 20, provided with a vehicle access ramp 22. The hopper 4 is pivotably connected to the subframe 19 by a hinged joint 24 which extends along the line of intersection of the wall 12 and the base 6. Heat insulating spacers (not shown) made from asbestos free brake lining material are interposed between the subframe 19 and the base pad 20. The spacers may for example comprise Ferodo (registered trade mark) packers.

A pair of hydraulic rams 26 extend on opposite sides of the hopper 4 and are pivotably connected at respective ends to the base pad 20 and the end wall 12 at an intermediate position along its length.

on the line of intersection of the end wall 12 and the base 6 is provided an outlet 28, which is connected to a screw conveyor 30. The screw conveyor 30 comprising an Archimedes screw which is driven by a power supply 33 comprising an electric motor or an internal combustion engine with suitable gearing.

Referring to Figure 2, end wall 12 tapers inwardly towards the base 6, such that the hopper 4 as a whole has the shape of an elongated funnel. The outlet 28 and screw conveyor 30 lie at the neck of this funnel.

The inlet of a belt conveyor 31 is situated beneath the screw conveyor 30.

The base 6, side walls 8, 10, end wall 12, top wall 14 and door 18 are of double skinned construction.

is The inner skin is formed from steel sheets welded together and the outer skin is formed from aluminium sheets fixed with rivets and sealed with silicone sealant and weatherproof outer cladding. The whole structure is stiffened by strengthening ribs 34 which are welded to the outer skin.

Insulating material such as a layer of Rockwool (registered trade mark) is sandwiched between the inner and outer skins to enhance the insulation properties of the hopper 4. Furthermore, heating devices such as thermostatically controlled trace heating elements (not shown) may be provided, for example between the inner and outer skins, for heating the hopper and maintaining a desired temperature of the paving material.

The outlet 28 is closed by a sliding gate arrangement such as a slide valve discharge door 36.

An electric geared motor (not shown) is used to open and close the door and operates in conjunction with the screw conveyor 30 to discharge paving material from the hopper 4.

Figures 3 and 4 show an alternative embodiment of hopper 4 in a raised position, with the hydraulic rams 26 extended. In this preferred embodiment, hydraulic locking pins 38 are provided at an end of the subframe 19. The hydraulic locking pins 38 are adapted to be received in recesses provided in an end of the base 6 of the hopper 4.

In addition, the embodiment of Figure 3 and 4 includes an internal door 40 which is pivotably connected to an upper edge of the side walls 8, 10 at an intermediate position along their length and is moved from an opened to a closed position by means of an electric winch arrangement (not shown). The internal door 40 is of steel frame construction, is encased in insulation and is provided with flexible skirts at its edges to improve its sealing function.

Referring again to Figure 1, the hopper 4 is shown in its lowered position. The door 18 has been raised hydraulically to provide lorry access to the interior of the hopper 4 through the opening 16. In this configuration, a tipper lorry 2 is reversed into the opening 16 and a load of paving material is tipped into the interior of the hopper 4. The lorry 2 then drives away and the 18 door is closed. The hydraulic rams 26 are extended causing the hopper 4 to rotate about the hinged joint 24 and thereby raising the opening 16 above the outlet 28 into the configuration illustrated in Figures 2 and 3. As the hopper is raised, the paving material falls under gravity towards the outlet 28, at which point the internal door 40 is lowered to prevent the loss of volatiles from the binder in the paving material into the larger void space. This is an important factor in extending the life of the coated material in the hopper.

The hydraulic rams 26 are then retracted, causing the hopper 4 to rotate back towards the base pad 20.

The door 18 is opened and a second tipper lorry 2 reverses into the opening 16 and tips its load of paving material into the hopper 4. The hydraulic rams 26 are operated again to raise the hopper 4 and the lid 18 is closed. When the hopper 4 is filled, it is locked in the raised position by means of the hydraulic locking pins 38.

with the hopper 4 in the raised position, paving material can be discharged through the outlet 28 via the screw conveyor 30, preferably onto the belt conveyor 31 illustrated in Figure 2.

The belt conveyor 31 may include a belt weigher which controls the weight of material discharged from the hopper 4 by closing the discharge door 36 automatically.

Although the above method has been described in relation to a tipper lorry 2 loading system, it is equally applicable to a system using a loading shovel and any other system in which it is useful to be able to access the opening 16 in the hopper at a lower level than when the hopper 4 is discharging paving material.

Furthermore alternative methods of raising the opening 16 relative to the base pad 20 are contemplated. For example the hopper 4 may be supported on a parallelogram linkage in which the links at the outlet end 12 are shorter than the links at the end of the opening 16. With such an arrangement, the whole hopper 4 is raised, but the opening 16 is raised more than the outlet 28.

Claims

1 A device for delivering aggregate, the device comprising:

a hopper having a filling opening for receiving aggregate at one end and an outlet for discharging aggregate at the opposite end; a support structure for supporting the hopper relative to the ground; and means acting between the hopper and the support structure for raising the said one end of the hopper into a discharge position.

2. A device as claimed in claim 1, in which the hopper is movable from a loading position in which the filling opening is disposed a first horizontal distance is and a first vertical distance from the outlet, to the discharge position in which the filling opening is disposed a second horizontal distance and a second vertical distance from the outlet, said first horizontal distance being greater than said second horizontal distance and the said first vertical distance being smaller than the said second vertical distance.

3. A device as claimed in claim 1 or 2, in which the raising means comprises at least one hydraulic or pneumatic actuator, pivotably connected to the hopper and the support structure.

4. A device as claimed in any one of the preceding claims, in which the hopper is pivotably connected to the support structure at the said opposite end.

5. A device as claimed in any one of the preceding claims, in which the hopper is fixed to a subframe to which the raising means is connected.

6. A device as claimed in claim 5, in which means are provided to thermally isolate the hopper from the subframe.

7. A device as claimed in claim 6, in which the isolation means comprises heat insulating spacers interposed between the hopper and the subframe.

8. A device as claimed in any one of the preceding claims, in which the support structure is adapted such that when the first end of the hopper is lowered, a lorry can be driven into the hopper through the filling opening.

9. A device as claimed in any one of the preceding claims, in which the hopper is mounted on one or more load cells.

10. A device as claimed in any one of the preceding claims, further comprising a screw conveyor adjacent the outlet from the hopper.

11. A device as claimed in any one of the preceding claims in which the outlet is closed by a sliding gate arrangement.

12. A device as claimed in claim 11, in which the sliding gate arrangement is opened and closed by a geared motor.

13. A device as claimed in claim 12, in which the sliding gate arrangement works in conjunction with a belt conveyor comprising a belt weigher, the sliding gate arrangement closing automatically, when a desired weight has been measured by the belt weigher.

14. A device as claimed in any one of the preceding claims, in which the hopper comprises an internal door mounted at an intermediate position along the length of the hopper.

15. A device as claimed in claim 14, in which the internal door comprises a hinged flap which is swung down from a wall of the hopper, to partition the hopper.

16. A device as claimed in claim 14 or 15, in which the internal door is operated by an electric winch arrangement.

11-

17. A device as claimed in any one of the preceding claims, in which the hopper is insulated.

18. A device as claimed in claim 17, in which the hopper is of double skinned construction, insulating material being sandwiched between the skins.

19. A device as claimed in any one of the preceding claims, in which the hopper is heated.

20. A device as claimed in claim 19, in which electrical heating elements are situated between the inner and outer skins of the hopper.

21. Method of filling a hopper with aggregate, the method comprising the steps of:

(a) partially filling the hopper with aggregate through a filling opening in an end of the hopper, with is the hopper in a filling position; (b) rotating the hopper about an end of the hopper opposite to the filling opening, such that the aggregate in the hopper falls under gravity towards said opposite end; (c) rotating the hopper back to the filling position; (d) putting additional aggregate into the hopper; and (e) repeating steps (b) to (d) until the hopper is full.

22. Method as claimed in claim 21, further comprising the steps of: