CROSS-RFFERENCE TO RELATED APPLICATION

The present application claims priority from Australian Provisional Putent Application No. 2010904973 filed on 10 November 2010, the contents of which are incorporated herein by reference.

FIELD OF INVENTION

this invention relates to a fluid evaporation device and system, and in particular, a water evaporation device and system for accelerated evaporation of waste water.

BACKGROUND ART

There exist a variety of industrial and non-industrial processes that produce a large quantity of waste water that should not or cannot bo legally discharged into rivers and waterways. Such industrial processes may include processes associated with manufacture, materials processing, mining, such as gas and coal extraction where wastewater is produced as a by-product of the drilling process or as a by-product of the extraction process, such as natural subsurface water or injected water. Other sources of wastewater may include waste brine irom a desalination plant; wastewater from drilling where water is used as a lubricant as well as to remove mine tailings lrom bore holes; sewage water, ibod processing wastewater, mineral reclamation wastewater and flood water and the like.

In such instances, the wastewater or fluid is typically collected in evaporation ponds where, over lime, the water is evaporated, thus separating the water from the waste. The waste may be then harvested in the form of crystals of other such solid matter tor further use, or disposed of appropriately. As a result of this, evaporation ponds are artificial ponds having a very large surface area to maximise evaporation of the water by sunlight and exposure to ambient temperatures.

Due to the fact that evaporation in ponds is a passive process, evaporation ponds are typically designed to have a capacity sufficient for the process for which the wastewater is a by-product. Tn many applications, particularly mining, the pond capacity must be significant and as the wastewater often contains toxins and various other types of contaminants, the pond must be suitably lined or otherwise isolated from natural waterways, to cater for the storage of such wastewater. Further to this, in order to design a suitable evaporation pond, much consideration much be given to locating the pond in a position that is remote from places where people can access and where potential leakage υΓ the pond amid cause widespread contamination to the environment. As a result, the costs associated with designing a pond of an appropriate size and at an appropriate location are considerable. I he costs associated with the removal of the remaining salts, solids, metals, compounds, substances and bittern from conventional ponds are also typically considerable.

With the above in mind, there is a need to provide a device and system that is directed towards accelerating the evaporation of wastewater in a variety of applications without requiring conventionally large evaporation ponds. There is also a need to provide a device and system that is directed towards accelerating the evaporation of a fluid that facilitates the ease of removal of waste from the site following evaporation of the fluid.

The above references to and descriptions of prior proposals or products arc not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art. in particular, the above prior art discussion docs not relate to what is commonly or well known by the person skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior art proposals is but one part.

STATEMENT OF INVENTION

According to a first aspect, there is provided a device for evaporating fluid comprising:

an open ftame member having an upper portion and a lower portion;

one or more fin members mounted to said frame member so as to extend at least partially between the upper portion and the lower portion, each fin member comprising a substantially porous material;

one or more fluid delivery outlets in communication with a fluid source and configured to deliver fluid to an upper region of one or more of the fin members to enable fluid to flow along the fin member to a lower region of the fin member; and

a collector located below the one or more fin members to collect and store fluid therein;

wherein the open frame member is configured to permit air flow therethrough such that as air passes through or across the one or more fin members evaporation of .fluid from the one or more fin members is facilitated, and any excess fluid present on the one or more fin members is received in the collector.

In one embodiment, the fin members comprise a substantially planar surface formed of substantially porous material. Each fin member may extend substantially between the upper portion and the lower portion of the open frame member. The one or more fin members may be arranged in one or more arrays, with each fin member in an array being oriented in the same direction. The one or more arrays of fin members may be mounted to said frame member. Each array may be detachably mounted to the frame member such that the orientation of each array within the frame member is variable.

The one or more fluid delivery outlets may be in the form of nozzles mounted to the open frame member so as to deliver fluid to one or more of the frame members. Λ heater clement may be provided to heal the fluid prior to delivery to the one or more fluid delivery nozzles. The heater clement may be u solar heater element. The one or more fluid delivery nozzles may drip feed fluid to an upper end of the fin members.

Tlie collector may be a fluid collection reservoir configured lo collect any fluid that pass through the device without evaporating.

The fluid source may be a waste water fluid source. In an alternative form, (he fluid collection reservoir may be the fluid source.

The flow of fluid through the device may be controlled by a programmable controller. A sensor may be provided lo detect a moisture content in the Iowa- region of one or more of the fin members and upon detection of the moisture content being below a predetermined level a rate of fluid delivery to the lin members is increased.

According to a second aspect, there is provided a water evaporation system for evaporating water form a source of waste water comprising:

one or more evaporators positioned over a water collection reservoir;

a wastewater supply in fluid communication with the one or more evaporators for supplying waste water thereto;

a heater clement for healing the wastewater being supplied to the one or more evaporators; a fluid recirculation system in fluid communication with the one or more water collection reservoirs and operational to deliver water from the one or more water collection reservoirs to the one or more evaporators; and a control unit for controlling the state of operation of the one or more evaporators and the delivery of wastewater to the one or more evaporators to ensure that a level of water present in the one or more water collection reservoirs is maintained at or below a predetermined level.

According to a third aspect, there is provided a method of evaporating wastewater in a wastewater treatment system comprising:

receiving a supply of wastewater from a wastewater source;

passing said supply of wastewater through an evaporation device that exposes said wastewater to a moving supply of air such that at least a portion of said wastewater is caused to be evaporated by said moving supply of air;

collecting the wastewater from the evaporation device that has not been caused lo evaporate; and

reluming the collected wastewater to the evaporation device.

Accordingly, in another aspect of the invention there is provided a device for evaporating fluid comprising:

an open frame member having an upper portion and a lower portion;

one or more arrays of elongate fin members mounted to said frame member so as to extend between the upper portion and the lower portion, each iln member comprising a substantially porous material;

one or more fluid delivery nozzles in communication with a fluid source and configured to deliver fluid adjacent an upper end of one or more of the fin members to enable fluid to flow along the fin member to a lower end of the fin member;

wherein the open frame member is configured to permit air flow through the device such that as air passes through the one or more arrays of fin members evaporation of fluid from the one or more fin members is facilitated.

In one embodiment, the one or more arrays of fin members arc orienlaled differently with respect to an adjacent array of fin members to maximise air How tlirough the device.

Λ heater element may be provided to heat the fluid prior to delivery to the one or more fluid delivery nozzles. The healer element may be a solar heater clement.

The one or more fluid delivery nozzles may drip feed fluid from the lluid source to an upper end of one or more of the fin members. Kach of the lin members may have an associated fluid delivery nozzle to drip feed fluid thereto.

The device may be positioned over a fluid collection reservoir to collect any lluid that may pass Irom the lower end of the lin members. I ^" he fluid collection reservoir may be the fluid source.

A sensor may be provided to detect the lluid stale of the lower end of one or more of the lin members and upon detection of the fluid state indicating dryness at the lower end of the one or more fin members, the rate of lluid delivery to the fin members may be increased.

In a preferred embodiment the fluid is wastewater.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be better understood Irom the following non-limiting description of preferred embodiments, in which:

Figure 1 is front view of an evaporation device in accordance with an embodiment of the present invention;

Figure 2 is a top view of the evaporation device of Figure 1 ;

Figure 3 is an evaporation system in accordance with an embodiment of the present invention;

Figure 4 is a perspective view of an alternalive embodiment of an evaporation system in accordance with the present invention;

Figure 5 is a top perspective view of an evaporator for use with the evaporation system of Figure 4 ;

Figure 6 is a top perspective view of a cartridge for use in the evaporator of Figure 5;

Figure 7 is a side view of an evaporator in accordance with yet another embodiment of the present invention;

Figure 8 is a top view of the evaporator of Figure 7;

Figure V is an end view of the evaporator ol'Figure 7; and

Figure 10 is an embodiment of a hook member for use in securing the sheet members in the evaporator of Figure 7.

DETAILED DESCRIPTION OF THE DRAWINGS

Preferred features of the present invention will now be described with particular reference to the accompanying drawings. However, it is to be understood that the features illustrated in and described with reference to the drawings arc not to be construed as limiting on the scope of the invention.

The invention will be described below in relation to its application in treating and processing waste brine, as may result as a by-product of Coal Scam (jas .(CSG) production or as a by-product of a coastal desalination plant. However, it will be appreciated that the present invention is equally applicable for the treatment of a variety of fluids firom a variety of different situations where there is a need to separate components present in the fluid, as will be appreciated by those skilled in the art.

Referring firstly to Figure 3, an accelerated evaporation system according to a first embodiment of the present invention is shown.

The system 20 employs an evaporator 10 that is configured to be positioned over a small pond or collection tray 27. The evaporator 10 is supported in the pond or collection tray 27 by one or more footings 29 which are typically made from concrete which may be lined and sealed with polyethylene for protection from the contaminants present in Ihe wastewater.

During use the wastewater, which may be waste brine, is delivered to the system 20 through delivery pipe 21. A non-return valve 22 may be provided in the delivery line 21 to prevent any back flow from the system 20. Upon entry into the system 20 the wastewater is first passed through a heater element 23 where it is heated in a first step to elevate the temperature of the wastewater. The healer clement is preferably a solar heater that utilises solar energy already present in the system. The wastewater may be heated to a desired tcinperdtiire which may be monitored and controlled by a controller unit 31 through a temperature sensor 24. The controller unit 31 may be in the form of a programmable logic controller, such as computer or the lilcc, thai can sense various operating conditions present within the system 20 and control the process accordingly. Jn this regard the controller unit 31 may be controlled by a user or may be programmed to provide automatic control in accordance with preset operating characteristics.

Following healing of the wastewater, any gas or vapour that may be generated as a result of die temperature of the wastewater being heated is vented into the environment by way of gas vent 25. The heated wastewater is then delivered to the evaporator 10.

Referring to Figures 1 and 2, the evaporator 10 is shown in isolation. The evaporator 10 is constructed to include a frame member 12 made Irom a suitable rigid material having a desired corrosion or contaminant resistance properties. In this regard, the frame member 12 may be made from stainless steel, timber, recycled plastic, galvanised steel or any other material.

The frame member 12 is configured to present a substantially boxed or cubed shape. The height of the frame member 12 may be determined to make best use of any available wind in the region where the evaporator 10 is sited. In one embodiment, the frame member may be greater than 6 metres high. A plurality of fins or sheet members 14 arc mounted to or within the frame member 12. Each fin or sheet member 14 is made from a suitable porous material, and the fins 14 are typically arranged in an array.

The fins 14 arc typically in the form of a sheet or film of porous material that extends in a substantially planar manner along the height of the frame member 12. The porous material may be a knitted polyethylene base material of the type that is often employed as shade cloth; however, other types of material, such as natural and synthetic materials arc also envisaged within the scope of the present invention.

As is shown in Figure 2, the fins 14 are arranged in a series of arrays that arc each orientated to face in differing directions within the frame member 12. Such a configuration of arrays of fins 14 ensures that, irrespective of the direction of any Wind, the wind will pass through the evaporator 10 and across the surfaces of the lins 14 to aid in evaporation of the wastewater that is present on the lins 14. The porous nature of the fins 14 ensures that there is minimal resistance to wind penetration into and through the evaporator 10. It will be appreciated that the lins may be coloured black to maximise heat absorption Irom the sun to further facilitate evaporation of the wastewater therefrom. Λ plurality of nozzles 16 are attached to the upper region of the frame member 12, as is depicted in Figure 3. The nozzles 16 act to deliver the heated wastewater directly onto the fins 14 from above, In this regard, the nozzles are preferably configured to drip feed the wastewater onto the fins 14 such, that the wastewater is able to flow along the surface of the fins 14, under gravity forces. The rate of supply of the wastewater may be varied in accordance with the rate of evaporation and in some instances the wastewater may be delivered onto the tins 14 by way of a spray nozzle. In this regard, the nozzles 16 function to ensure that the planar surfaces of the fins 14 are wet, or retained in a moist state, along the lengths thereof.

As the wastewater travels along the fins 14 under gravity, atmospheric air or wind passing through and/or between the fins 14 acts to evaporate the wastewater from the surface of the fins 14, thereby allowing the wind to carry the water vapour away. As the evaporator 10 is positioned over a small pond or collection tray 27, any wastewater that is not evaporated from the fins 14 is received or collected in thc pond or tray 27. Ihe wastewater can then be continually recycled until it has been evaporated, as will be described in more detail below.

In order to control the rate of delivery of the heated wastewater to the fins 14 of the evaporator 10, a sensor 26 is positioned adjacent the lower end of one or more of the fins 14. The sensor 26 senses the degree of moisture present in the lower regions of the fins 14 and if the degrco of moisture is determined to be below a predetermined level such that it is substantially dry, the rate of delivery of the wastewater is increased. This ensures that the evaporator operates at maximum efficiency and that the entire surface area of the fins 14 is able to he exposed to the passing air, thus maximising evaporation of liquid therelirom.

Whilst not shown, the evaporator 10 may comprise one or more fans mounted on or in the structure thereof, to facilitate air flow therethrough. As is shown in Figures 1 and 2, a vent 15 is provide in the upper surface of the evaporator and a fan may be mounted in or on the vent to draw air through the structure of the evaporator 10 to further facilitate and accelerate evaporation of the wastewater from the fins 14.

As discussed above, any non-evaporated wastewater flowing along the surfaces of the fins 14 will typically collect below the evaporator 10 in the pond or collection tray 27 for recycling. In order to control the amount of wastewater being collected in the pond or tray 27, a float sensor 28 is employed to detect the level of wastewater being stored therein. Upon detection of the level of wastewater in the pond or collection tray 27 reaching a predetermined maximum level, die float sensor 28 sends a signal to the controller uuit 31 to stop further delivery οΓ the wastewater to the system 20 by way of inlet 21. The controller uuit 31 then activates the pond pump 30 to recycle the collected wastewater by pumping the pondwater cither directly to the nozzles 16 or to the nozzles 16 via the heater 23, as is shown in Figure 3. Such an arrangement ensures that tile amount of wastewater being stored within the pond or tray 27 is maintained at a desired level and is ultimately consumed by evaporation, leaving behind the contaminant or waste product which can be collected lor disposal, treatment and/or reuse.

Referring to Figure 4, an alternative embodiment of an evaporation system 35 of the present invention is shown. In this system,, two crystallisation ponds 36 are employed to store wastewater during the process. As will be appreciated, the process will typically be controlled in the same manner as described above and operates on the same general principles of evaporation.

Wastewater is fed to the system 35 from a source via a feed line 41 , The wastewater is then delivered by way of a pump 37 to a heating system 38, which comprises an array of solar healing panels. In the embodiment as shown, the solar heating panels may be made from a high density polyethylene (IIDPE) as is conventionally used in heating water lor pools and the like as such panels are highly durable and reliable for use in heating water via solar power. However, it will be appreciated that other arrangements and systems for healing the received wastewater are also envisaged.

Following heating, the heated water is Ihen pumped to the evaporator 40 which is mounted within a collection pad 39. The collection pad 39 forms a perimeter about the evaporator 40 to collect any wastewater that passes through the evaporator 40 without being evaporated during the process. As in the system described above in relation to Figure 3, such an arrangement provides an ability to recirculate the wastewater through the system 35.

Ine evaporator 40 functions in substantially the same manner as described above, and comprise a plurality of fins or sheet members arranged in one or more arrays mounted within a frame member. The sheet members are made from a porous or open film of material which receives the wastewater from one or more spray nozzles mounted thoreabove in an upper region of the evaporator 40 and arc orientated such that wind or air is able to pass therethrough thus facilitating evaporation of the wastewater irom die sheet members.

Any wastewater that passes through the evaporator 40 without evaporating is collected in the collection pad 39 and accumulates therein. Once the level of wastewater accumulated in the collection pad 39 has reached a predetermined level, it is delivered to one or both of the crystallisation ponds 36 through delivery line 42.

Once the wastewater is received in the crystallisation ponds 36 it is exposed lo the sun and is able to crystallise in a conventional manner. Any crystallised waste material, such as salt and the like, is able lo be directly harvested from the ponds 36 and the collection pad 39, as desired. The level of the wastewater present in the ponds 36 is also monitored such thai it can be returned to the evaporator 40 via delivery line 43. Typically, wastewater is maintained in a single pond 36 and once the water in the pond 36 crystallises, the second pond is able lo receive wastewater whilst the crystallised wastewater is harvested.

Tt will be appreciated that in the system 35 as shown in Figure 4, a large amount of wastewater can be processed through the use of multiple crystallisation ponds 36 and the collection pad 39. The system 35 is controlled by a Programmable Logic Controller (PLC) that is able to control the delivery of wastewater throughout the process. The use of sensors present in Ihe evaporator ensures that Ihe array of sheet members arc consistently kept moist through activation of the spray nozzles and maintains the ponds 36 at a desirable level. It will also be appreciated that the system 35 may employ multiple evaporators 40 to further accelerate evaporation of the wastewater and such a system has a particular application lo mining situations and the like, where there is a need to provide a system with a large capacity to handle wastewater.

Referring to Figure 5, the evaporator 40 is shown in more detail. The evaporator 40 comprises a frame member 44 in the form of a cube or box. the frame member 44 is made from a non-corrosive material and defines an internal space into which is received one or more cartridges 45, which are shown in Figure 6

Each cartridge 45 comprises a secondary frame member 48 which receives a plurality of sheet members 46. The sheet members 46 arc arranged within Ihe secondary frame member 48 such that they are orientated in substantially the same direction and are each spaced apart by approximately 50 mm. It will be appreciated that other orientations and spacings may also be employed depending on the specific operating characteristics of the system. As discussed above, the sheet members 46 arc made from a substantially porous material and are substantially planar so as lo provide a front and rear vertical surface along which wastewater can travel from the nozzles located at the top of the evaporator 40 to the collection pad 39 located below the evaporator 40.

As is shown in Figure 5, the cartridges can be orientated within the frame 44 of the evaporator 40 such that they all extend in the same direction or extend in orthogonal directions. The orientation of the cartridges may be selected to take into consideration the direction of the wind and the local conditions in the region in which the evaporator is installed. As the cartridges 45 arc supported within the frame 44, they can be readily removed and rc-orienlaled should wind conditions change. In this regard, should one or more ol ^' the sheet members 46 become fouled or otherwise damaged, the cartridges can also simply be replaced as required in a simple and cost effective manner.

Referring to Figures 7 and 8, yet another embodiment of art evaporator 50 according to the present invention is shown. In this embodiment, the evaporator 50 can be employed in a large scale environment to process large volumes of wastewater, such as up to and beyond 2 Mega litres/day.

The evaporator 50 can be formed such that it can assume any length desirable. In the embodiment as shown in Figures 7 and 8, the length L of the evaporator 50 may be 75m and the width W may be 5.8m, however other configurations and sizes are also envisaged.

Prior to use, a collection pad 51 is constructed about the evaporator 50 and the evaporator 50 is typically operated in the manner as discussed above. The evaporator 50 comprises a pair of end supports 52 wluch are typically made from a treated metal, such as steel or a non-corrosive plastic material. Λ plurality of intermediate support members 5.1 are provided at intervals along the length of the evaporatoT 50, to provide support to the overall structure. The number and spacing between the intermediate support members 53 will largely depend upon the length of the evaporator being constructed. In any event, the end supports 52 and the intermediate support members 53 arc typically mounted within the collection pad 51 so as to be self supporting.

A fluid delivery arrangement 54 is mounted on an upper each of the end supports 52 and intermediate support members 53 so as to extend along the length of the evaporator 50. The fluid delivery arrangement 54 is in fluid communication with a wastewater source so as to receive and deliver the wastewater to the evaporator 50 in a manner to be discussed in more detail below.

A pair of cables 55a and 55b are provided to extend along the length of the evaporator 50 along opposing sides thereof. The cable may be in the form of a wire rope or other similar arrangement and the cables are each mounted to a gronnd siirlace at each end thereof and pass through holes 56 provided in the end supports 52 and intermediate support members 5.1 at upper and lower regions thereof. As is clearly visible in Figure 7, the upper cable 55a extends along an upper region of the evaporator 50 whilst the lower cable 55b extends along a lower region in the manner as shown in Figure 7 and Figure 9. Ihe cables 55a, 55b each provide a means for mounting the sheet members 60 to the evaporator 50.

Referring to Kigure 9, Ihe manner in which tho sheet members 60 arc mounted within tho evaporator 50 is shown. l-,ach sheet member 60 is typically substantially rectangular in shape so that each sheet member 60 is mounted at upper corners to the upper cables 55a and at the lower corners to the lower cables 55b. As the cables 55a, 55b extend along the entire length of the evaporator 50 and are tensioned, they provide a plurality of lines to which the sheet members 60 are mounted.

In one embodiment of the present invention, in order to mount the sheet members 60 top the evaporator 50, a hook member 70 is employed, lite hook member 70 is shown in Figure 10 and comprises a pair of arm members 72, 73 that are sufficiently resilient so as to clamp about the cable 5Sa, 55b once fitted. Arm member 73 is configured to engage with the other arm member 72 so that both arm members act to apply the clamping force about the cable 55a, 55b, so as to prevent movement of the hook member 70 along the length of the cable 55a, 55b during use. This ensured that the position of the hook member 70, and thus the sheet member 60, remains substantially fixed relative to the length of the evaporator 50. The arm member 72 has a hook region provided al its extremity to engage with a hole or recess provided in a region of the sheet member 60. As is shown in Figure 9, when each of the hook members 70 is attached to each of the cables 55a and 55b, the sheet member 60 extends across the width of the evaporator 50, and is retained in a taut manner. By arranging a plurality of sheet members 60 along the length of the evaporator 50 in the manner as shown in Kigure 7, such that there is a gap of approximately 50mm between adjacent sheet members 60, the evaporator 50 is assembled.

It will be appreciated that the use of hook members 70 to mount the sheet members in position is merely represented of one embodiment for achieving this purpose. Tt will be appreciated that the sheet members may be mounted in position along the length of the evaporator 50 through the use of a variety of different means, whilst still falling within the scope of the present invention. The hook members 70 merely provide a means for assembling the evaporator to a customised length and other means for achieving this can aJso be employed.

As is shown in Figure 9, when assembled, the fluid delivery arrangement 54 dial extends along a top of the evaporator 50 is able to deliver wastewater to each sheet member 60 by way of the spray nozzleso 58. The position and number of spray nozzles may vary depending upon the type of delivery mechanism employed, namely spraying or drip feeding of the wastewater, on to the sheet members 60.

It will be appreciated that the evaporator 50 is positioned such that wind or air is able to pass beiween the sheet members 60 and in doing so, cause evaporation of the wastewater present on the front and rear surfaces thereof. By consistently delivering the wastewater to the sheet members 60 to ensure that the sheet members have sufficient moisture upon their surfaces, any excess wastewater is captured in the collection pad surrounding the evaporator 50. This collected wastewater can then be recirculated and heated in the manner as described above to facilitate evaporation and crystallisation.

It will be appreciated that the device and system of the present invention in the various embodiments discussed above, provide a means for utilising natural wind and solar power to evaporate wastewater at upwards of 10 times the rate normally achieved in existing evaporation ponds. It will also be appreciated that as the footprint of the device and system of the present invention is significantly smaller than that of equivalent evaporation ponds presently in use, the present invention oilers considerable cost savings to industry users.

It will be appreciated that the present invention could be readily adapted to function as a source of pure water. In this regard, an additional device can be incorporated in the evaporator system that enables evaporated water from the system to be condensed and collected as pure water for reuse or for safe and useful disposal to the environment. Hence, by providing a condensor system having a condensor plate or plates or condensor material that is cooled by a coolant consisting of liquid, air, gas, heal pump, electrical or other means, the evaporated water could be collected and condensed into pure water. A coolant circulation pumping system and a control system could be employed to achieve this and the condenser could be positioned such that the wind is directed over the condensor system by way of a fan or array of fans, The condensed water could then be collected and distributed as recovered water.

Throughout the specification and claims the word "comprise" and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary is expressly slated or the context requires otherwise. That is, the word "comprise" and its derivatives will be taken to indicate the inclusion of not only the listed components, steps or features that it directly references, but also other components, steps or features not specifically listed, unless the contrary is expressly staled or the context requires otherwise.

It will be appreciated by those skilled in the art that many modilications and variatioivs may be made to the methods of the invention described herein without departing from the spirit and scope of the invention.

Orienlalional terms used in the specification and claims such as vertical, horizontal, top, bottom, upper and lower arc to be interpreted as relational and are based on the premise that the component, item, article, apparatus, device or instrument will usually be considered in a particular orientation, typically with the evaporator uppermost.