Patent Application
20140263720
The present invention relates to a liquid spray apparatus and system, such as for use in dust suppression from vehicles.
There are many applications for liquid spray apparatus and systems, such as for fire fighting both from vehicles and in static installations, for agriculture in irrigating/watering crops or grass, and in dust suppression at industrial sites, such as road building, landfill sites and mine sites.
The following description will focus on applications for dust suppression. However, one or more forms of the present invention may be used wherever control of liquid delivery by spraying is required.
Large open area sites where the underlying soil is disturbed often require some form of dust suppression. This is conducted for environmental reasons, chiefly to prevent movement of windblown (potentially contaminated) soil from one area to another, but also to prevent soil blowing as dust into urban, commercial or traffic areas. Governmental and environmental concerns for public health and safety have increased consciousness for the need to control dust emanating from such sites and operations. Controlling dust created by vehicle movements helps to improve workers conditions, improve local community acceptance of the presence of the site and operations carried out, and increased productivity because vehicles and their operators are able to travel faster and more safely due to improved vision of the immediate roadway edges and surface as well as a clear road ahead.
Mine sites, road/building construction sites and landfill sites are typical examples of where such dust suppression is needed. Dust is typically created where excavators have moved or removed the topsoil covering and the underlying soil has dried out. On mine sites, for example, roadways are created inclining down into the mine. These roadways are used to gain access into the mine and by the dump trucks (aka haul packs) to remove the mined material out of the mine. Constant use creates dust on the roadway surface which needs to be damped down. A water tanker/water cart or adapted dump truck carrying a reservoir of water are generally used to spray the water over the ground surfaced to damp down the dust. The simplest form of spraying uses a spray bar or series of spray heads across one end of the vehicle to deliver a spray of water as the vehicle traverses forward/backward. However, other than an on-off control of the water spray, no other control was used. Consequently, regardless of the speed of the vehicle the sprays would deliver water at a near constant rate (subject to water pressure from the ever reducing onboard reservoir).
More recent developments have introduced speed controlled spraying. The amount of water delivered when spraying is related to the speed of the vehicle. An example of such a system is disclosed in international patent application PCT/US98/02601 published as WO 98/35104. An electrostatic water spray dust suppression system for use with vehicles is disclosed. A control system monitors movement of the vehicle, and activates or deactivates the sprayer(s) dependent upon movement and speed of the vehicle. Such a system relies on creating a fog of electrostatically charged water droplets that, due to their electrostatic charge, are mutually attracted to dust particulates in the air. The water droplets and dust particulates agglomerate and fall to the ground. However, very fine spray head apertures are required to create the fine fog or mist spray. Also, an electrostatically charged tip is required to transfer charge to the water droplets as they are sprayed. The fine spray apertures can easily become clogged in the very dusty environment or due to hard water causing calcification over time, or because the water may not be sufficiently filtered before being sprayed. Furthermore, fine fog/mist spraying produces very light droplets that can tend to be blown by the wind away from the area to be damped before having any significant effect, resulting in water being wasted.
The aforementioned spraying equipment and techniques does not provide for adjustment of the spray pattern or direction. The vehicle travels forward/backward over the area to be damped and simply sprays outward/downward in a linear pattern using fixed spray heads in the direction the vehicle is traveling, whether or not the spraying is speed controlled.
There is also a need to conserve and not waste water. Water spraying related to vehicle speed helps to reduce water wastage by reducing over watering of road areas when the vehicle is travelling slowly or under-watering when the vehicle is travelling faster. Over-watering can occur when a water cart or truck is travelling up an incline and engine revs (and therefore the water pump output) are high. This can result in washing away of the road surface.
To apply sufficient water across the width of an industrial site roadway, often up to 25 m wide or more, it is necessary to use multiple spray heads. Typically three spray heads will be used simultaneously across the width of a spray bar on the vehicle—one in the centre and one each towards the left and right ends of the spray bar. Such a configuration creates some overlap between the centre and each of the left and right end spray patterns. This results in more water applied in the centre of the roadway than at the edges. The overlap areas can cause the roadway to wear or wash away over time, causing potholes or gullies in the roadway.
The spray pattern and amount of water delivered can be adjusted by setting each of multiple spray heads. The width and depth of the spray aperture of each spray head across a spray bar of a vehicle can be manually adjusted and set. However, correct adjustment is difficult to obtain and retain. Variations in water pressure also vary the spray pattern, and consequently, some overlap or non-sprayed area will occur.
It has been realized that a single spray head able to cover the full desired width of spray is desirable.
With the aforementioned in mind, it is desirable for the present invention to provide an adjustable spray head for spray delivery of a liquid to an area, the spray head having an adjustable width and direction of spray.
The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of admission that the prior art forms part of the common general knowledge in Australia.
With the aforementioned in view, an aspect of the present invention provides a liquid spray head configured, in use, to deliver a spray of liquid for dust control, the spray head including a body, an inlet for receiving the liquid to be sprayed, an outlet for delivery of the liquid for spraying, at least one adjuster arranged to adjust size and/or position the outlet such that a width or position of the outlet is variable or both the width and position of the outlet are variable, relative to the body, to thereby deliver a desired rate, pattern or direction of liquid spray.
Thus, advantageously, the rate, width and/or direction of spray may be controlled for a single spray head a single spray head with variable width and variable control of volume or rate of liquid delivery. Thus, not only may the width and/or position of the outlet be controlled, but also the pressure, and therefore rate of flow through the spray head may be controlled.
The adjuster may be mechanically actuated, such as by one or more rams (which may be hydraulically or pneumatically operated) or by one or more electrically driven solenoids. Thus, remote operation of the spray head can be effected, such as from a cabin of a vehicle or other remote location, such as a control centre, for a remotely operated vehicle.
The spray head may include coaxial leafs (inner and outer leafs) within or connected to the body. The leaves define the outlet between a respective edge of each leaf, and the leafs may be rotated relative to one another about the common axis. Thus, the size of the outlet may be controlled between a minimum aperture to a maximum aperture. Minimum aperture may be a fully closed aperture. Also, position of the outlet may be varied by relative rotation of the leaves such that the leaf edges defining the outlet is effectively rotated relative to the body. It will therefore be appreciated that the spray pattern and direction may be varied by adjusting the angular width and/or position of the outlet.
It will therefore be understood that three adjustments may be made:
Left and right side angular adjustment to control the width and position of the outlet, and thirdly the outlet depth (spray head depth).
Left and right adjustment may be up to around 90 degrees left and up to around 90 degrees right from a centreline, such as a centreline of the vehicle or roadway i.e. 180 degrees coverage side to side in total.
The spray head may be adjusted in conjunction with vehicle road speed or engine/pump speed. For example, the spray head outlet and pump speed may be controlled by a vehicle speed signal, such as from a processor.
It may be possible to replace the processor with a signal from a vehicle information management system. Such a system can provide a greater integration for the spray head and system, and therefore be more familiar to maintenance personnel having particular knowledge of the vehicle carrying the reservoir of liquid to be sprayed.
The liquid may be water, but may alternatively be water containing dust suppression chemicals, or may be a foam type liquid, which may be water based foam. Chemical(s) may be introduced to the water as it is sprayed, such as by eduction, or may be contained with the water prior to spraying.
A multi-stage water pump drive may be used. For example, a three stage drive hydro-motor may be used to adjust pump speed in three steps. Thus, the pump may be maintained within a speed range and therefore within a desired liquid delivery pressure range. Switching between pump drive stages may be effected by mechanical or electrical operation. For example, a solenoid controller may be used to selectively actuate pump speed stages.
Liquid delivery pressure may be controlled by providing a pressure relief system enabling return of liquid back to the onboard supply reservoir.
A processor, controller or vehicle information management system may utilise vehicle engine speed to adjust the pump drive stages in operation, thereby maintaining water pressure and water pump speed within a desired range. The processor, controller or vehicle information management system may use a signal relating to a vehicle speedometer signal as a factor influencing adjustment of the spray head outlet, such as relating to vehicle ground speed.
In use, the spray head outlet is adjusted by the vehicle operator dependent upon a desired spray pattern, direction and/or rate of delivery. Operator controls, such as in a cabin or external control panel of the vehicle provide for left and right spray width adjustment. The operator therefore determines left and right angular extent of the spray pattern.
Spraying may be controlled by an actuation means, such as a switch or foot pedal in the vehicle. The actuation means may be ON from a vehicle standing start. As vehicle speed increases, say past 5.0 km/h, spraying comes into operation. As vehicle speed increases, the spray head outlet volume control may come into operation, thereby permitting a greater liquid flow rate through the outlet to match increased vehicle speed. The faster the vehicle travels the more liquid needs to be put through the spray head. Thus, vehicle speed and liquid spray volume can be matched proportionally.
The pump drive may be switched off and supply of liquid to the spray head may be isolated, such as by using an isolation valve and/or liquid return system, when liquid spraying is not required or the vehicle speed is below a selected speed, say 5.0 km/h,
The spray head may be used for pulse spraying the liquid. Pulse spraying is a technique used on ramps and inclines of roadways. Spraying is turned on and the road surface is wetted for a certain distance, then spraying is interrupted and the road surface left dry for a certain distance. Typically, 50 meters wet 50 meters dry, though other distances of wet-dry are envisaged. Pulse spraying provides a safety feature. A vehicle, such as a dump truck, travelling down a ramp fully loaded may skid under braking on the wet area is able to regain control in the dry area. At least one embodiment of the present invention provides for liquid spraying control via a controller which utilizes pulse spraying by controlling opening and closing the outlet aperture of the spray head. The outlet aperture may be gradually opened and closed, such as in a sinusoidal wave form control, rather than a just on-off-on of known pulse spraying. Pulse spraying control may be effected using the controllability and variability of the spray head actuator(s) rather than a simple onboard isolating valve shutting off supply from the pump. This would have the effect of making the whole road surface wet but the volume of liquid in some areas is only light thereby still aiding dust control but also allowing vehicles to maintain contact under braking when traveling down an incline or prevent wheelspin on an incline.
The spray head may be used as part of a water cannon or hose reel supply system. Alternatively, the spray head may be connected to a fixed installation where variable angular liquid delivery, direction and/or volume are required, which may be effected remotely or manually by adjustment of the spray head adjuster.
The spray head may form part of a liquid spray system, including a reservoir of a liquid to be sprayed, a pump and connecting conduit to deliver the liquid from the reservoir at pressure to the spray head, pump control means to control pump speed, and spray head adjustment control means to control the outlet of the spray head to effect a desired angular spray width, and preferably spray direction and spray volume.
The spray head may include a hydraulic actuator, such as a cylinder or ram, operatively connected to the cam of the rotary actuator. Connection may be by linkage, such as a lever. The hydraulic actuator may be fitted with a resilient return means, such as a coil spring. Thus, once the hydraulic actuator is extended, the resilient return means returns the cam, and thus the cam operated vertical movement of the spray head opening, to a closed position or partially open/closed position. A hydraulic control valve may be fitted that provides a variable pressure to this actuator. In use, the hydraulic actuator extends and retracts against the spring force according to the increase or decrease in hydraulic pressure it receives. The hydraulic control valve may communicate with a PLC, which preferably takes a road speed input and converts it into a signal to control the hydraulic pressure to the cylinder. Thus, as the vehicle moves faster the cylinder extends and provides the mechanical force to operate the variable mouth width of the spray pattern.
One or more embodiments of the present invention may include a control system to control actuation of the spray head. Such control systems may employ hydraulics and meter the spray mouth aperture by controlling hydraulic pressure.
a and 3b show respective right side and left side perspectives of a spray head showing spray width adjustment means according to an embodiment of the present invention.
The invention will now be described with reference to the accompanying figures.
Each ram is pivotably connected to the respective collar assembly via a pivot 20,21 and pivot bracket 22,23.
A spray head body cover assembly 24 covers the lower extent of the inner and outer collar assemblies and the spray head depth (aperture depth/height) adjuster. This cover assembly also provides the outlet aperture adjusting sleeve 36. This outlet aperture sleeve is moved up or down relative to the left and right width adjusting leaves 25,26. A depth actuator situated inside the cover 24 pushes against or pulls towards a plate 34, thereby acting on the supports 38 on the base 40 of the cover 34. This action causes the side wall 42 of the sleeve 36 to move up and down as needed, thereby varying the upright depth of the outlet aperture 25 by vertically reducing or increasing the outlet aperture 25 opening.
a to 2c show the spray head in top, front and side view. The front view,
a and 3b show right and left perspectives of the spray head 10 with actuator rams 17, 18. The left hand ram 17 is shown retracted and the right hand ram extended. The leaf 26 of the right hand collar assembly 15 is therefore rotated to the left. The leaf 27 of the left hand collar assembly 16 is also shown rotated to the left. A gap is formed between the respective edges 28,29 thereby defining the outlet aperture 27, rotated to the left side of the spray head 10.
The angular position and width of the outlet aperture 27 can be varied depending on the extent of rotation of each leaf 25,26 and in which direction they are each rotated.
In use, the spray head can be installed as part of a liquid spraying system. Typically the spray head might be used mounted to a vehicle in a water spraying system for use in damping down roadways. However, other applications are deemed to fall within the compass of the present invention. For example, in fire fighting applications or oil hydrocarbon dispersal applications. A pump delivers the liquid to the spray head from a supply reservoir. This reservoir may be carried by a vehicle to which the spray head is mounted or by a separate vehicle, such as a water tanker. Because of the adjustability of the outlet aperture of the spray head, only a single spray head is needed to cover a full width of a typical roadway. The width of the spray head outlet aperture can be increased or decreased by the adjuster. This allows the angular spray pattern to be adjusted. Also, the bias towards the left side, straight-ahead or right side can be adjusted by moving the outlet aperture towards the left, straight or right as required. Furthermore, optionally the depth/height of the outlet aperture can be adjusted to increase flow rate through the aperture. Thus, with variable control of width and height/depth of the outlet aperture, and direction, one single spray ahead can be used to provide a required spray pattern or amount of liquid. Adjustment can be linked to cabin controls, and optionally to a variable speed pump. Flow rate can be linked to vehicle speed so that the amount of liquid being sprayed is matched to vehicle speed and road conditions. A higher flow rate can be used where the vehicle is moving faster. Flow rate can be controlled to match vehicle speed even if engine speed is high, such as when negotiating a steep incline. A variable stage pump drive may be employed so that pump speed is matched to delivery requirements. If a high volume flow rate is required with the vehicle static, such as in a fire fighting role, the vehicle can be parked, the pump driven at high speed via the multi stage pump drive and the engine driving the pump set at high revs.
Varying the width of the outlet aperture can be achieved by varying the separation between edges of sections of coaxially aligned sleeves. Rotary movement of one sleeve relative to the other causes a change in the width of the aperture and therefore a change in spray pattern. Flow rate can be varied by adjusting the height of the outlet aperture as well as pump speed. A rotary or linear actuator may be employed to control the height of the aperture.
A rotary actuator 76 includes an actuator cam 78. Eccentricity of the cam causes the lower casing 80 to move up or down depending on the direction of rotation of the cam. This movement varies the vertical opening height of the spray aperture 82. The cam is rotary actuated by an actuator mechanism 84 connected by a linkage 86 between a first actuator mechanism arm 88 and a cam actuator arm 90. rotation of the cam causes the cylindrical casing 80 to move up or down depending on the direction of cam rotation. This varies the opening height of the aperture created between the edges of the curved members 66,68. Thus, selected positions of the curved members and the outer casing determine spray direction, spray angle and spray rate (volume and/or distance of spray). Spray pressure may also be controlled by a valve prior to the liquid entering the spray head or within the spray head. Reference item 92 shows movement direction arrows relating to control of the aperture opening and thus the spray pattern 94.
Complete closure of the spray head aperture may be effected by moving together the edges of the curved members and/or moving the outer casing upwards, or both.
In the cutaway
A filter can be provided in the supply to the spray head. This may be a coarse filter to remove larger debris from the water (such as rocks, sticks etc). A finer filter can be provided as required. A filter can help prevent the aperture becoming blocked with debris or the opening/closing mechanism becoming jammed. Spray volume may be varied by controlling pump speed or varying the pump capacity i.e. by changing the pump for a larger/smaller pump or adding one or more additional pumps.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011904225 | Oct 2011 | AU | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/AU2012/001231 | 10/12/2012 | WO | 00 | 4/11/2014 |
