GB2045840A

GB2045840A - Heating apparauts

Info

Publication number: GB2045840A
Application number: GB7911759A
Authority: GB
Original assignee: THORMACK ENG Ltd
Current assignee: THORMACK ENG Ltd
Priority date: 1979-04-04
Filing date: 1979-04-04
Publication date: 1980-11-05
Also published as: EP0017499A1

Description

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GB 2 045 840 A 1

SPECIFICATION Heating apparatus

5 The present invention relates to heating apparatus which is, for example, suitable for heating up road repairing materials.

When potholes appear in roadways, it is often advantageous to mend these as soon as is practic-10 able after they are formed. However, this is often very difficult to achieve. The standard technique is for the repairer to obtain a lorry load of hot asphalt from an asphalt supplier and to take this to the site where the repairs are to be effected. The repairs are 15 carried out on the first few potholes, but after a while the asphalt becomes too cool to be readily usable and it is therefore usually wasted.

This is a very wasteful method of operating and is therefore not satisfactory.

20 It is now proposed, according to the present invention, to provide a heating apparatus comprising a drum rotatable about its axis, an outlet opening at one axial end of said drum, an auger mounted within said drum to feed material within said drum 25 axially thereof, a port at the other end of the drum, a flashback condition burner mounted with its discharge opening in said port and drive means to rotate said drum about its axis selectively in one direction of rotation or the other.

30 With such an arrangement, the asphalt to be heated can be heated on site and indeed can be mixed at the same time. The material to be heated is fed in to the drum which is rotated in one direction to cause the material to be heated and mixed to flow 35 away from the outlet opening towards the port. When the flashback condition burner is ignited, it produces a high velocity jet of very hot gases which will warm the asphalt sufficiently to make it workable. When it has attained the desired temperature, 40 the drum is caused to rotate in the opposite direction at which time the burner can be turned off. With the drum rotating in the opposite direction the auger causes the material to feed out of the outlet opening where it can be taken up by the workman in a 45 suitable receptacle and used.

Advantageously, the flashback condition burner is releasably mounted with respect to the drum so that it can be readily dismounted. With this arrangement, it is possible to use the flashback condition burner to 50 prepare the pothole priortothe application of the hot asphalt. Use of the burner will firstly blow out any dust or debris within the pothole and secondly, will heat the pothole so that it will form a good bond with the hot asphalt.

55 Preferably, the drum is mounted for rotation about a substantially horizontal axis and the drum is provided with a tapered portion which terminates in the outlet opening.

Desirably, the flashback condition burner is 60 mounted in the port in the drum so that substantially no air is entrained into the drum by the discharge gas stream. This has the advantage that there will be no tendency for any combustion to take place within the drum. The products of combustion of the 65 flashback condition burner are largely carbon dioxide and nitrogen, but there will be a tendency for there to be some unburned gas in the gas stream. This will not be allowed to ignite if there is no combustion air available.

70 Although the drum can be filled through its outlet opening, a closable inlet opening, for example a door, is preferably provided in the drum at a location axially spaced from the outlet opening.

In order that the invention may more readily be 75 understood, the following description is given, merely by way of example, reference being made to the accompanying drawings, in which :-

Figure 1 is a side elevation of one embodiment of heating apparatus according to the invention; and 80 Figure 2 is an end elevation of the apparatus of Figure 1.

Referring now to the drawings, there is illustrated therein a heating apparatus which is mounted on a chassis 10 provided with roadwheels 11. A drum 12 85 is mounted on the chassis for rotation about a substantially horizontal axis 13.

The lefthand end of the drum, as seen in Figure 1, is tapered at 14 and terminates in a discharge opening 15.

90 At the other end of the drum, the end wall 16 is provided with a central axial port 17 in which is mounted a flashback condition burner, that is a burner which is powered by gas and compressed air and in which the combustion takes place completely 95 within the combustion chamber. The burner is provided with an outlet opening, on the left as viewed in Figure 1.

The burner is fed with compressed air from a compressor 19 and with gas, for example, propane, 100 from a cylinder 20 by inlet lines 21 and 22 respectively.

The burner 18 is mounted in a channel 24 and is releasably held in place by a clamp 23. It will be noted that the outside diameter of the burner 18 is 105 very little smallerthan the diameter of the port 17 so that there will be little chance of air being entrained into the drum by the discharge gases of the burner.

The drum is mounted for rotation on two frames 30 and 31 carried by the chassis and is supported on 110 lower rollers 32 and 33 carried by the frames respectively. The drum is held down by rollers 34 and 35 urged towards the axis 13 by springs 36 and 37 respectively.

It will be seen that there are mounted within the 115 drum four strips 38, these forming an auger which is rotatable with the drum. Only one strip is shown in Eigure 1.

In order to cause the drum to rotate, a motor 39 is mounted on the chassis and drive is achieved by a 120 belt 40 passing round a pulley on the motor and around an axial flange portion 41 on the rear wall 16 of the drum surrounding the port 17.

An inlet (which may for example have a hinged inlet door 42) is provided on the drum at the end 125 remote from outlet 15.

In use, material to be mixed to form asphalt, that is bitumen and aggregate, is introduced in through the inlet 42 and the drum is then caused to rotate in a direction such that the auger tends to move the 130 material to be mixed to the right in Figure 1,that is

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GB 2 045 840 A

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towards the end wall 16 and away from the outlet opening 15. The compressor 19 is put into operation to feed compressed air via line 21 and a valve is opened on the gas container 20 to feed gas via line 5 22 to provide a combustion mixture within the chamber 18 which is ignited. A hot blast of combustion gases is thus discharged into the drum. This operation is continued for a short time to ensure that the material within the drum is all heated to the 10 desired temperature. The drum is then stopped and the burner 18 removed by releasing the clamp 23. The pothole to be treated is then cleaned out and preheated by means of the burner and the drum is rotated in the opposite rotational sense so that hot 15 asphalt can flow out of the outlet opening 15 under the action of the auger 38. The material is then placed in the pothole which will be hot and a good bond will be achieved between the asphalt and the surrounding road surfacing material. 20 The arrangement of the present invention can be used in substantially all weathers. Even if the ground is wet and it is raining or snowing, or even if there is frost, the action of the burner on the road surface will ensure that the roadway is dry and clean and the fact 25 that hot asphalt is immediately applied ensures a good bond so that further work need not be done at a later date. Furthermore, there need be little or no waste of the asphalt material because this can be kept hot by replacing the burner from time to time.

the accompanying drawings.

Printed for Her Majesty's Stationery Office by Croydon Printing Company Limited, Croydon Surrey, 1980.

Published by the Patent Office, 25 Southampton Buildings, London, WC2A1 AY, from which copies may be obtained.

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Claims

CLAIMS 40 45

1. Heating apparatus comprising a drum rotatable about its axis, an outlet opening at one axial end

35 of the drum, an auger mounted within said drum to feed material within said drum axially thereof, a port at the other end of the drum, a flashback condition burner mounted with its discharge opening in said port and drive means to rotate said drum about its axis selectively in one direction of rotation or the other.

2. Apparatus according to claim 1, wherein said drum is mounted for rotation about a substantially horizontal axis.

3. Apparatus according to claim 1 or 2, wherein the drum is provided with a tapered portion which terminates in said outlet port.

4. Apparatus according to claim 1,2 or 3, wherein flashback condition burner is releasably mounted

50 with respect to the drum so that it can readily be dismounted.

5. Apparatus according to any preceding claim, wherein the flashback condition burner is mounted in the port so that substantially no air is entrained into the drum by the discharge gas stream of the burner.

6. Apparatus according to any preceding claim, wherein a closable inlet opening is provided in the drum at a location axially spaced from its outlet aperture.

7. Apparatus according to any preceding claim, wherein the drum, drive means and burner are mounted on a wheeled chassis.

8. Heating apparatus substantially as hereinbe-

65 fore described, with reference to and as illustrated in

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