AU2015200481A1 - Forest fire-fighting machine - Google Patents

Abstract

The present invention is directed generally to a forest fire-fighting machine 10 comprising a mobile chassis 12 together with a boom 14 mounted to the chassis 12. The fire-fighting machine also comprises an axially flow fan 16 mounted to the boom 14. The boom 14 is configured to located the axial fan 16 at a forest fire-front and to provide sufficient air flow via the fan 16 to extinguish or suppress the fire-front. C:\poi\od\SPCN-1 019541.docx -- - --- --------- -- -- -- - --- ~ ~ ------ -- -- -- --- , ----- N' Fig. --- ------- --- ------- - ' H g.

Description

Forest Fire-Fighting Machine

Technical Field [0001 ] The present invention relates broadly to a forest fire-fighting machine, typically vehicle-mounted.

Background of Invention [0002] There exist a variety of fire-fighting techniques in suppressing forest fires. These existing practices all rely upon removal of at least one of the ingredients of the fire or combustion triangle, namely oxygen, heat and fuel. In Australia the typical firefighting practices fall into two (2) categories involving either: i) directly attacking the fire with water and other fire suppressants via firefighting crews, fire engines or air tankers; or ii) defensively or indirectly addressing the fire by creating fire breaks in order to burn fire fuel loads [0003] The defensive approach may only be effective when the direction of travel of the fire-front can be accurately predicted and thus the fire break located in the correct position to holt the travel of the fire. In any event the equipment required to construct the fire break is relatively large and can be quite destructive of the surrounding land and environment. The offensive approach in directly attacking the fire suffers from at least the following drawbacks: i) the firefighter is put at risk particularly with a rapidly advancing fire-front; ii) the equipment required to offensive fire-fighting must be frequently “refilled” in terms of both the fire suppressant and the fuel which powers the equipment and valuable time is lost.

Summary of Invention [0004] According to the present invention there is provided a forest fire-fighting machine comprising: a mobile chassis; a boom mounted at a proximal end to the mobile chassis; an axial flow fan coupled to the boom at its distal end whereby in operation the boom is configured to locate the axial fan at a forest fire-front and provide sufficient airflow via the fan to extinguish or supress the fire-front.

[0005] Preferably the axial flow fan is configured to generate air velocity of greater than 50 km/hr. More preferably the axial flow fan includes a casing surrounding its radially-extending blades. Even more preferably the axial flow fan includes one or more fins extending from the casing for directing the extinguishing air flow toward the fire-front. Still more preferably the axial flow fan includes either 3 or 4 of the radially extending blades.

[0006] Preferably the boom is extendible. More preferably the extendible boom is telescopic. Even more preferably the boom is pivotally mounted to the mobile chassis about a substantially horizontal axis for raising and lowering of the boom at its distal end. Still more preferably the boom is mounted to the chassis for swivelling about a substantially vertical axis for swinging of the distal end of the boom.

[0007] Preferably the fire-fighting machine also comprises one or more discharge nozzles mounted to the boom at its distal end and adapted to direct an extinguishing fluid at the fire-front to supplement the extinguishing air flow from the axial flow fan in extinguishing or suppressing the fire-front. More preferably the discharge nozzles are in fluid communication with a fluid storage vessel mounted to the mobile chassis and adapted to contain the extinguishing fluid. Even more preferably the storage vessel is coupled to the discharge nozzle via an extendible hose.

[0008] Preferably the axial flow fan includes a direct-drive motor. More preferably the direct-drive motor is electrically actuated. Even more preferably the electrical actuation of the direct-drive motor is independent of power for mobilising the mobile chassis.

[0009] Preferably the mobile chassis is associated with a land-based motor vehicle such as a mobile crane.

Brief Description of Drawings [0010] In order to achieve a better understanding of the nature of the present invention a preferred embodiment of a forest fire-fighting machine will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a forest fire-fighting machine of a preferred embodiment in its transport position;

Figure 2 is a side elevational view of the forest fire-fighting machine of figure 1 together with an optional fluid storage vessel;

Figure 3 is a plan view of the fire-fighting machine of figure 1;

Figure 4 is a side elevational view of the fire-fighting machine of figures 1 and 3;

Figure 5 is n opposite side elevational view of the fire-fighting machine of figure 4;

Figure 6 is a front view of the fire-fighting machine of the preceding figures;

Figure 7 is a side elevational view of the fire-fighting machine of the preceding figures in one mode of operation attacking the fire-front;

Figure 8 is a plan view of the fire-fighting machine of the preceding figures in another mode of operation moving along the fire-front.

Detailed Description [0011 ] As shown in figures 1 to 6 there is a forest fire-fighting machine 10 of a preferred embodiment of the invention. The fire-fighting machine 10 is shown in its transport position. The fire-fighting machine 10 generally comprises a mobile chassis 12 together with a boom 14 mounted to the chassis 12. The mobile chassis 12 is part of a land-based vehicle such as a truck 13. The fire-fighting machine 10 also comprises an axial flow fan 16 mounted to the boom 14 at its distal end 18. The boom 14 is configured to locate the axial flow fan 16 at a forest fire-front (see figures 7 and 8) and to provide sufficient air flow via the fan 16 to extinguish or suppress the fire-front.

[0012] As best shown in figures 7 and 8 the boom 14 of this embodiment is extendible. The extendible boom 14 includes three (3) telescopic section 20A to 20C which are retractably received within one another. The fire-fighting machine 10 is shown in figure 7 with the telescopic boom sections 20A to 20C fully extended in the operative or fire-fighting position. In this example the vehicle 13 is stationary and the mobile chassis 12 is appropriately stabilised via hydraulic and retractable props such as 22A and 22B. In figure 8 the fire-fighting machine 10 in the operative mode has the vehicle 13 moving parallel to the fire-fighting front 24. The extendible boom 14 in this fire-fighting position is shown fully retracted in order to improve the stability of the machine 10.

[0013] The axial flow fan 16 is preferably designed to generate air velocities of greater than 50 kilometres per hour (km/hr) or roughly 30 knots. This relatively high extinguishing air flow 30 is effective in both: 1. extinguishing the fire 26 by removing heat from the fire-front 24; and 2. supressing or extinguishing the fire by halting the fire-front 24 in its general direction of travel and thus removing fuel.

[0014] The axial flow fan 16 in providing this relatively high extinguishing air flow 30 thus serves to remove heat and fuel in extinguishing or suppressing the fire 26. In the absence of or with relatively light breezes advancing the fire 26, the extinguishing air flow 30 effectively blows out the fire-front 24. In moderate to relatively strong breezes, the extinguishing air flow 30 is designed to oppose the predominant breeze or travel of the fire-front 24 so that it effectively runs out of fuel and thus burns out.

[0015] Returning to figures 1 to 6, the axial flow fan 16 includes a casing 32 surrounding its radially-extending blades such as 34A to 34D. The cylindrical casing 32 at its discharge end is connected to a pair of fins 36A and 36B curved in profile to match the cylindrical casing 32 and extending parallel to one another. The fins 36A and 36B together with the casing 32 are configured to direct or concentrate the relatively high velocity extinguishing air flow 30 toward the fire-front 24. In this embodiment the axial flow fan 16 includes four (4) of the radially-extending blades 34A to 34C although it will be appreciated that four or more blades may also be suitable. The axial flow fan 16 is designed to generate relatively high pressures at or proximal the discharge end and this in combination with the high velocity air flow is effective in extinguishing fires.

[0016] In this embodiment the telescopic boom 14 is both pivotally mounted to the mobile chassis 12 about a horizontal axis, and arranged for swivelling about a vertical axis. The mobile chassis 12 includes a platform 38 mounted for swivelling about the vertical axis at the rear of the vehicle 13. The extendible boom 14 pivotally mounts to the swivelling platform 38 about the horizontal axis for raising and lowering of the boom 14 at its distal end 18. The swivel platform 38 is provided with a pivot-mount assembly 40 to which a proximal end 42 of the extendible boom 14 is pivotally mounted about the horizontal axis.

[0017] In this embodiment the fire-fighting machine 10 may also comprise one or more discharge nozzles such as 44 mounted to the extendible boom 14 at its distal end 18. The discharge nozzles 44 are adapted to direct an extinguishing fluid, such as water, at the fire-front 24 to supplement the extinguishing air flow 30 from the axial flow fan 16 in extinguishing or suppressing the fire-front 24. In this variation, the discharge nozzles 44 are in fluid communication with a fluid storage vessel 46 via an extendible hose 48. The storage vessel 46 is mounted to the chassis 12 of the vehicle 13 underneath the boom 14. The extinguishing fluid may be delivered to the discharge nozzle 44 with the assistance of a centrifugal pump (not shown). The centrifugal pump may be mounted to the mobile chassis 12 adjacent the storage vessel 46 and coupled to the extendible hose 48. The extendible hose 48 is in this example retracted and/or extended via a hose reel 57 which is either powered electrically (via a drive motor) or manually. The hose reel 57 may be mounted to the extendible boom 14.

[0018] The axial flow fan 16 of this example includes a direct-drive motor (not shown). The direct-drive motor is electrically-actuated independent of power for mobilising the mobile chassis 12. The direct-drive motor is mounted integral with the axial flow fan 16 at or adjacent the distal end 18 of the extendible boom 14. In this example the direct-drive motor is electrically powered via a diesel-generator (not shown). The diesel-generator is associated with a control cabin 49 mounted to the swivelling platform 38. Electrical cabling 51 interconnecting the diesel generator and the direct-drive motor is mounted to the extendible boom 14 to permit its extension and retraction. The cabling 51 may be mounted to a reel 55 fixed to the boom 14 which permits its extension and retraction. The cable reel 55 may be electrically (via a drive motor) or manually powered for rotation to effect its extension and/or retraction.

[0019] In this example the fire-fighting machine 10 includes a hydraulically-actuated ram 50 mounted between the lowermost telescopic section 20A of the extendible boom 14 and the swivelling platform 38. The diesel generator associated with the control cabin 49 powers a hydraulic motor (not shown) coupled to the hydraulic ram 50. The hydraulic ram 50 is thus extended for pivoting of the extendible boom 14 about the mount assembly 40 for raising of the axial flow fan 16. The hydraulic ram 50 on retraction pivots the boom 14 for lowering of the axial flow fan 16.

[0020] The fire-fighting machine 10 can operate in a variety of modes and positions. Figure 7 is a schematic side elevation view of the machine 10 operating in its stationary mode attacking a relatively limited fire-front such as 24. In this stationary mode the machine 10 may operate as follows: 1. The vehicle 13 is manoeuvred to face the fire-front 24; 2. The extendible boom 14 is raised and typically fully extended by an operator working from the control cabin 49; 3. The operator then activates the axial flow fan 16 with it positioned at or around canopy level 50 of the fire 26; 4. The extinguishing air flow 30 extinguishes or suppresses the fire-front 24, particularly at the canopy level 52; 5. The operator can swivel the platform 38 for repositioning of the axial flow fan 16 across the fire-front 24; 6. The operator may also raise or lower the extendible boom 14 via the hydraulic ram 50 to position the axial flow fan 16 at the appropriate height in the canopy 52 depending on the vertical position of the fire such as 26.

[0021] In operation of the fire-fighting machine 10 in its stationary mode, the hydraulic props such as 22A and 22B stabilise the vehicle 13. It is expected that the axial flow fan 16 will generate reverse thrust forces which may have a tendency to tip the vehicle 13. If the extendible boom 14 is swivelled away from the centre line of the vehicle 13 the stabilising props such as 22A and 22B are designed to at least inhibit lateral rocking or tipping of the chassis 12. It is expected that swivelling of the extendible boom 14 may need to be limited depending on the extent of the reverse thrust force of the axial fan 16 and the extent to which the extendible boom 14 is extended.

[0022] In another mode of operation schematically shown in figure 8 the firefighting machine 10 is designed to be moved across the fire-front 24 by driving the vehicle 13 parallel to the fire-front 24. This mode of operation involves the following steps: 1. The vehicle 13 is positioned adjacent to the fire-front 25 in the required direction of travel; 2. The swivelling platform 38 is swivelled about 90 degrees wherein the axial flow fan 16 faces the fire-front 24; 3. The hydraulic ram is actuated for pivoting of the extendible boom 14 so that the axial flow fan 16 is elevated to the canopy level such as 52; 4. The axial flow fan 16 is activated to provide the extinguishing air flow 30 directed predominantly at the canopy level 50 of the fire-front 24; 5. The vehicle 13 is manoeuvred or driven parallel to the fire-front 24 to continue extinguishing of fire at predominantly the canopy level 50.

[0023] In this mobile mode of operation, the extendible boom 14 is preferably retracted to reduce tipping forces exerted on the mobile chassis 12 induced by the reverse thrust force provided by the axial flow fan 16. The reverse thrust force may also prove effective in countering or balancing the tipping force generated by the weight of the axial flow fan 16 mounted at the distal end 18 of the extendible boom 14. In any case it is likely that, depending on the size/weight of the axial flow fan 16 and the speed at which it is operated, the extension on the extendible boom 14 may need to be limited in this mobile mode of operation.

[0024] The size of the machine may vary depending on the scale of the typical fire against which it is likely to be deployed. In the case of a relatively large scale forest fire, the machine 10 of the preceding embodiment is likely to be suitable. In this embodiment the fire-fighting machine 10 has the following design parameters: 1. The axial flow fan 16 is likely to generate air flow with a minimum of 60 kilometres per hour at rotational speeds for the fan 16 of around 3,500 rpm; 2. The casing 32 of the axial flow fan 16 has a diameter of around 1.5 metres and the associated electric motor has a power requirement of around 15kW; 3. The radial blades 34A to 34C have an effective diameter of around 1.2m and the fan 16 is expected to generate a flow of extinguishing air at around 1400m3/min; 4. The extendible boom 14 has the capability to provide a maximum reach of up to around 40 metres; 5. The extendible boom 14 can in operation be raised to maximum height of around 35 to 40 metres; 6. The axial flow fan 16 would typically be located at a distance of around 3 to 5 metres from the fire-front and would provide coverage of around 2 to 4 metres across the face of the fire-front 24.

[0025] The velocity of the extinguishing air flow can be derived or calculated under these design and operating parameters. Based on volumetric flowrate of 1400m3/min, the extinguishing air velocity will be around 75km/hr or about 40 knots.

If the rotational speed is increased to 5,000rpm and assuming the volumetric flowrate is proportional to the rotational speed then the volumetric flowrate at this increased rpm will be around 2,000m3/min. This equates to an extinguishing air velocity at about 115km/hr or roughly 60 knots. If the power requirement is assumed to be proportional to the rpm then the electric motor has an increased power of around 45kw. The maximum power rating for the electric motor is up to around 90kw so this increased power requirement is still within specification.

[0026] The axial flow fan 16 may include a grid or guard 53 on its front face. The guard 53 may include relatively large square-shaped openings at around 200mm by 200mm. The guard 53 is expected to reduce the flowrate of the extinguishing air by around 10%.

[0027] Now that a preferred embodiment of the present invention has been described it will be apparent to those skilled in the art that the forest fire-fighting machine has at least the following advantages: 1. The machine relies upon an indefinite supply of air for extinguishing the fire and thus does not require "refilling"; 2. The machine is designed in its preferred form to elevate to the canopy level for extinguishing or suppressing fire at or around that level; 3. The machine is relatively safe in operation where an operator can locate within the security of the control cabin; 4. The mobile chassis in the form of a motor vehicle can escape a rapidly approaching fire, if this proves necessary; 5. The machine is relatively non-destructive, for example it permits the escape of fauna in the region of the fire.

[0028] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described.

For example, the axial flow fan may be of a different configuration to that described provided sufficient air flow is created for extinguishing or suppressing the fire. The machine may also be of a different scale where for example it is trailer-mounted. The boom need not extend and/or swivel provided it has the functionality to locate the axial flow fan at the required fire region. The various drive system for the machine may be controlled remotely, for example activation of the axial flow fan may be controlled away from the machine itself. Although the preferred embodiment is shown with the ability to tilt the axial flow fan, the fan and its associated casing may be fixed to the boom without the ability to tilt. All such variations and modifications are to be considered within the scope of the present invention the nature of which is to be determined from the foregoing description.

Claims (16)

1. Claims

   1. A forest fire-fighting machine comprising: a mobile chassis; a boom mounted at a proximal end to the mobile chassis; an axial flow fan coupled to the boom at its distal end whereby in operation the boom is configured to locate the axial fan at a forest fire-front and provide sufficient airflow via the fan to extinguish or supress the fire-front.
2. 2. A forest fire-fighting machine as defined in claim 1 wherein the axial flow fan is configured to generate air velocity of greater than 50 km/hr.
3. 3. A forest fire-fighting machine as defined in claim 1 or 2 wherein the axial flow fan includes a casing surrounding its radially-extending blades.
4. 4. A forest fire-fighting machine as defined in claims 3 wherein the axial flow fan includes one or more fins extending from the casing for directing the extinguishing air flow toward the fire-front.
5. 5. A forest fire-fighting machine as defined in either of claims 3 or 4 wherein the axial flow fan includes either 3 or 4 of the radially extending blades.
6. 6. A forest fire-fighting machine as defined in any one of the preceding claims wherein the boom is extendible.
7. 7. A forest fire-fighting machine as defined in claim 6 wherein the extendible boom is telescopic.
8. 8. A forest fire-fighting machine as defined in either of claims 6 or 7 wherein the boom is pivotally mounted to the mobile chassis about a substantially horizontal axis for raising and lowering of the boom at its distal end.
9. 9. A forest fire-fighting machine as defined in any one of claims 6 to 8 wherein the boom is mounted to the chassis for swivelling about a substantially vertical axis for swinging of the distal end of the boom.
10. 10. A forest fire-fighting machine as defined in any one of the preceding claims also comprising one or more discharge nozzles mounted to the boom at its distal end and adapted to direct an extinguishing fluid at the fire-front to supplement the extinguishing air flow from the axial flow fan in extinguishing or suppressing the fire-front.
11. 11. A forest fire-fighting machine as defined in claim 10 wherein the discharge nozzles are in fluid communication with a fluid storage vessel mounted to the mobile chassis and adapted to contain the extinguishing fluid.
12. 12. A forest fire-fighting machine as defined in claim 11 wherein the storage vessel is coupled to the discharge nozzle via an extendible hose.
13. 13. A forest fire-fighting machine as defined in any one of the preceding claims wherein the axial flow fan includes a direct-drive motor.
14. 14. A forest fire-fighting machine as defined in claim 13 wherein the direct-drive motor is electrically actuated.
15. 15. A forest fire-fighting machine as defined in claim 14 wherein the electrical actuation of the direct-drive motor is independent of power for mobilising the mobile chassis.
16. 16. A forest fire-fighting machine as defined in any one of the preceding claims wherein the mobile chassis is associated with a land-based motor vehicle.