Abstract:
A cleaning device having one or more water holding tanks having associated water supply outlets connected thereto and an associated pumping means to effect a supply of cleaning water under pressure from each of the one or more holding tanks; the device further including one or more return tanks having associated therewith a water return tank and a water return inlet and associated suction means to allow collection of water into the one or more return tanks. The water holding tanks are in fluid communication with the return tanks and having a series of intermediary filter and baffle elements positioned in a water flow path such that water passing from a return tank to a holding tank is subjected to sequential settling action en route.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a cleaning device. In particular, the present invention relates to a device and method used for cleaning surfaces such as roadways. Further, the present invention relates to a cleaning device that permits the recycling of cleaning water.  
       BACKGROUND OF THE INVENTION  
       [0002]     There are many occasions on which small areas of a road way or other similar surface might require cleaning and washing over a limited area. For example, where road works involve the cutting of sections of the road large amounts of dust and particulate concrete and so on are produced in the cutting action. Similarly, where spills of particulate matter occur quantities of the contaminant may remain after the road surface has been swept. In the past the response to such situations has been simple to flush the affected surface and allow the particulate material, dust and the like to be washed into a stormwater drain and carried away. However, it has now been recognised that water resources are precious and that water catchment flowing into reservoirs, and into streams, rivers and oceans should not be contaminated undesirable materials. Local authorities have assumed some responsibility for water resource management and have taken steps to ensure that only appropriate materials enter the water supply.  
         [0003]     To ensure that actions comply with legislation it is necessary to prevent materials from entering the storm water system. The present invention has been conceived with this in mind.  
       SUMMARY OF THE INVENTION  
       [0004]     Therefore, according to a first aspect of the present invention there is provided a cleaning device including:—
        one or more water holding tanks having associated water supply outlets connected thereto and an associated pumping means to effect a supply of cleaning water under pressure from the one or more holding tanks;     one or more return tanks having associated therewith a water return tank and a water return inlet and associated suction means to allow collection of water into the one or more return tanks;     the one or more holding tanks being in fluid communication with the one or more return tanks and having a series of intermediary filter and baffle elements positioned in a water flow path such that water passing from a return tank to a holding tank is subjected to sequential settling action en route.        
 
         [0008]     Thus, the device of the invention is adapted to hold a store of cleaning water in a holding tank and supply the cleaning water, under pressure to a surface to be cleaned. Through the return inlets used water can be collected under suction and held in the return tank. The used water may also incorporate a number of contaminant particulate materials which it would be undesirable to recirculate. The intermediary baffle elements allow a series of sequential separating steps to occur that remove the unwanted material. The device of the invention has been conceived principally for use in cleaning of road surfaces and, for this reason is preferably made of a relatively rugged construction. Further, it is not the purpose of the device to seek to remove all particulate contaminants but to clean the water sufficiently to allow recirculating of the water for further flushing and cleaning purposes.  
         [0009]     The inventor has thus realised that for many cleaning and flushing purposes a traditional filter arrangement is unsuitable. For example a filter that is overly fine may require a high degree of maintenance and be subject to frequent blocking. Similarly a filter of too high a specification may require large amounts of energy, typically in the form of increased pressure to ensure that the a sufficient flow rate of water can be maintained through the unit. The unit of the invention provides for a relatively simple and rapid residency time that enables the water to be subject to a multi-stage settling and cleaning of gross contaminants.  
         [0010]     Preferably, intermediary filter and baffle elements includes a first basket filter located below an inlet of the return tank and adapted to collect and retain large particulate material that settles under the action of gravity.  
         [0011]     The intermediary filter and baffle elements may further include one or more settling area located in either the holding tank or the return tank, the settling area allowing water to remain there for a period and to allow particulate contaminants to settle and to allow water to pass out of the settling area by means of a water overflow or underflow device.  
         [0012]     Preferably, the suction means associated with the one or more return tanks comprises a vacuum operative to produce a vacuum in a head space in the return tank. In such an arrangement, by maintaining the liquid level in the return tank and the supply tanks the vacuum side of the device may be separated from the pressure side of the device. 
     
    
     DESCRIPTION OF DRAWINGS  
       [0013]     For a clearer understanding of all its aspect the invention will now be described by way of example only with reference to the accompanying drawings in which:  
         [0014]      FIG. 1  shows in schematic perspective view a cleaning device in accordance with a first aspect of the present invention;  
         [0015]      FIG. 2  illustrates the cleaning device of  FIG. 1  including all hose connections;  
         [0016]      FIG. 3  illustrates in cross section the cleaning device of  FIG. 1 ;  
         [0017]      FIG. 4  shos a cutaway sectional view of a portion of the device of  FIG. 1 ;  
         [0018]      FIG. 5  illustrates in rear perspective view a second embodiment of the invention; and  
         [0019]      FIG. 6  illustrates a third embodiment of the invention 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0020]     Shown in the drawings are cleaning devices  10  ( FIGS. 1-4 ),  60  ( FIG. 5 ), and  100  ( FIG. 6 ). In each case the devices  10 , 60  and  100  operate on similar principles and have a number of features in common. The cleaning devices  10 ,  60 ,  100  are designed to be filled with a recirculating water supply and include a number of interconnected water holding tanks. Where like features are described in the drawings like numerals will be used to refer to these features.  
         [0021]     Turning to the device illustrated in  FIGS. 1-4 , the cleaning device  10  includes an arrangement of three separate water holding tanks being a centrally located water return tank  12  and two outer water holding and supply tanks  14   a ,  4   b  respectively. In the embodiment under consideration the tanks of the device are constructed of steel and have been hot dip galvanized to improve their corrosion resistance. As can be seen to bets advantage in  FIG. 2 , the tanks  12 ,  14   a  and  14   b  have associated therewith water supply hoses  16   a ,  16   b , a water return hose  18  and sundry pipe connections to be described in detail hereinbelow. In broad detail water circulates through the system from the tanks  14   a ,  14   b  through the hoses  16   a ,  16   b  and is returned through the return hose  18  into the return tank  12 .  
         [0022]     The water supply system is driven by a pump  20  positioned beneath the return tank  12 , which is elevated with respect to the supply tanks  14   a , 14   b  to accommodate the pump  20 . Leading out of the pump  20  is a supply manifold pipe  22  to which the hoses  14   a  and  14   b  are connected. The supply from each of the hoses  16   a ,  16   b  is also controlled by means of respective valves  24   a ,  24   b . Each of the hoses  16   a  and  16   b  are attached to a respective hose reel  26   a  and  26   b  connected to the upper surface of the supply tanks  14   a ,  14   b.    
         [0023]     The pump  20  draws a water supply from the supply tanks  14   a ,  14   b  through supply line  28  which has an opening  28   a ,  28   b  in each of the tanks  14   a ,  14   b . The tanks  14   a ,  14   b  hold a supply of cleaned water to be used in the cleaning and mopping process for which the device  10  is suited. Thus, the openings  28   a ,  28   b  of the supply line  28  are located spaced apart from the base of the tanks  14   a ,  14   b.    
         [0024]     The return tank  12  includes an inlet point  30  to which is attached the inlet hose  18 . The inlet hose  18  terminates in a suction head  34  used to collect water that has been used for flushing/cleaning actions and any spills needed to be collected. The inlet point  30  is close to an upper corner of the return tank  12 .  
         [0025]     Adjacent the inlet point  30  and positioned on top of the return tank  12  is a vacuum device  36 . The vacuum device  36  is in fluid communication with the suction head  34  through the hose  32  and serves to provide the motive force that collects water through the suction head. The vacuum device has an external power supply (not shown).  
         [0026]     Alternatively, the vacuum device can be connected to a mains power supply or to a vehicle power supply.  
         [0027]     The device  10  is not designed for the purposes of producing a pristine surface and there is no requirement that the water, or other fluid supplied from the tanks  14   a , 14   b  be entirely free of contamination. For general flushing and cleaning purposes it is, however, preferable that any gross contaminants are removed from the water. It will also be appreciated that larger particulate contaminants in the water could potentially interfere with the action of the pump apparatus  20  and that accordingly it is desirable to have such particles removed.  
         [0028]     Water or other fluid entering the return tank  12  through the inlet point  30  is confined to a corner of the return tank  12  by means of an angular baffle  38  that, together with the corner of the tank  12  defines a generally columnar space that extends downwardly from an upper corner of the tank  12  to a lower corner of the tank  12 . The base of the return tank  12  below the baffled section  38  slopes towards downwardly. Thus, water entering the return tank  12  is directed to travel downwardly in the space and any heavy particulate material carried in the water settles at the bottom of the tank  12  which has a sloping bottom  40  to facilitate this process. In some forms of the invention a removable collecting basket (not shown) can be positioned below the columnar section to facilitate easy removal of any material collected.  
         [0029]     As the liquid level in the return tank  12  rises a separation of the heavier contaminants from the water has occurred, and, accordingly, the water towards the upper surface is cleaner. At a certain point the water level encounters a series of overflow apertures  42  in the sides  41  of the return tank  12  that are common to the return tank  12  and the holding tanks  14   a ,  14   b  on either side of the tank  12 . The apertures  42  are generally aligned horizontally and allow water to flow from the return tank  12  into each of the water holding tanks  14   a ,  14   b . The overflow apertures are positioned such that the water flows into the water holding tanks  14   a ,  14   b  at an upper edge thereof.  
         [0030]     The water holding tanks  14   a ,  14   b  are partitioned from their upper edges by a partition  44  that extends parallel to the inner sides  41  of the tanks  14   a ,  14   b  from an upper inside surface of the tanks  14   a ,  14   b  towards the bottom of the tanks. A gap  46  exists between a lower edge of the partition  44  and the base of the tanks  14   a ,  14   b.    
         [0031]     Thus water entering the tanks  14   a ,  14   b  is initially directed in a downward flow direction thereby encouraging any remaining undesirable particulate material to settle on the base of the tanks. As the level rises in the tanks  14   a ,  14   b , the water is available for recirculation through the openings  28   a ,  28   b.    
         [0032]     Thus, in use the device  10  may be carried on a trailer to any site where it is needed and with relatively low water wastage perform a cleaning or surface flushing function. Where the device becomes full of liquid unsuitable for further use it is possible to drain each of the tanks  12 ,  14   a , and  14   b  through lowermost drain holes  50 . Similarly, at any remote location, the tanks can be opened through hinged lids  52  for more thorough cleaning.  
         [0033]     An alternative form of the invention is illustrated in  FIG. 5 . In most respects the device  60  is identical to the device  10 . However, located at the rear of the device is a pair of element filters  62  arranged in series in the supply line extending from the pump  20 . The element filters  62  each have attached thereto a respective purge valve  64  that enables the line to be purged should the line become blocked. Further the arrangement can be set up such that the pump stops when the filter becomes blocked. Such an arrangement might be preferred where a positive displacement pump is used in the device.  
         [0034]     It is also possible to create a cleaning device in accordance with the invention using modular tanks that are inter connected to allow flow there between.  FIG. 6  illustrates such an arrangement where three distinct tanks are used to create an arrangement  100 .  
         [0035]     The invention has been described by way of example. The examples are not, however, to be taken as limiting the scope of the invention in any way. Modifications and variations of the invention such as would be apparent to a skilled addressee are deemed to be within the scope of the invention.