The present invention relates generally to a mobile aggregate washing apparatus, used for, for example, scrubbing, screening, washing, floatation, classification, dewatering, magnetic metal removal and stock piling of aggregates. The mobile aggregate washing apparatus is designed to process either virgin aggregates or a variety of recycled aggregates and remove contaminates such as silt, clay, and detritus materials to produce stockpiles of clean sand and gravel aggregates.

Background to the Invention

Aggregates are materials commonly used for construction sub-bases, concrete production, drainage and utility schemes. They include sand, gravel and crushed rock.

Traditional aggregate wash plants have a number of constituent parts. One such constituent part is typically a washing apparatus, with either scrubs aggregate to remove unwanted material or uses a water bath and high-pressure water injection to wash off the unwanted material. These traditional aggregate wash plants are designed to be broken down into their constituent parts for storage and transport from one location to the next. This results in considerable set-up times on-site and the use of many vehicles to move the constituent parts into position.

Such static, modular aggregate wash plants come with a number of drawbacks. For example, prior planning permission is needed to install such a plant and this permission can take a lot of time and money to be granted. Moreover, installation time for such static, modular aggregate wash plants can be from 3-4 weeks to 3-4 months depending on the size of plant. In addition, these static, modular aggregate wash plants require months of drawing and commissioning time on site. Also, construction works needed for a static aggregate wash plant constitute an expensive investment. It is a therefore an object of the present invention to provide an improved aggregate washing apparatus eliminating the need to amass various separate components for different stages of the washing process, while at the same time allowing easy transport of the components as a unit.

Summary of the Invention

The present invention relates to a mobile aggregate washing apparatus, wherein multiple components are mounted on a tracked chassis, eliminating the need to amass various separate components for different stages of the washing process, while at the same time allowing easy transport of the chassis and components as a unit.

Accordingly, a first aspect of the present invention is a mobile aggregate washing apparatus for scrubbing and screening aggregate material, the apparatus comprising: a chassis provided with at least one track which is operable to move the apparatus from place to place, an aggregate scrubbing unit mounted on the chassis, the aggregate scrubbing unit having an inlet for receiving aggregate material; means for moving said aggregate scrubbing unit from a horizontal position with respect to the chassis upwards to an inclined position at an angle to the chassis and from the inclined position downwards to the horizontal position, a first screen unit mounted on the chassis, means for raising and lowering said first screen unit relative to the chassis; a second screen unit mounted on the chassis, and means for raising and lowering said second screen unit relative to the chassis.

The mobile aggregate washing apparatus is capable of transitioning between a transport configuration and a working configuration and vice versa.

Mounting the components of the mobile aggregate washing apparatus on a single chassis, which is mobile, eliminates the need to amass various separate components for different stages of the washing process, while at the same time allowing easy transport of the chassis and components as a unit. The mobile aggregate washing apparatus of the present invention is designed to achieve full mobility of the apparatus, the ability to transport the apparatus easily and much quicker speed of installation. It is also more economical to install and operate than conventional static aggregate wash plants and does not require prior planning permission.

The mobile aggregate washing apparatus will remove contaminates such as silt, clay, and detritus materials from the aggregate. Such detritus materials typically include organic material such as leaves or sticks as well as plastics. The word trash is also used herein to describe contaminates.

The or each track may independently be run over at least one wheel attached to the chassis. The mobile aggregate washing apparatus may comprise a first track which runs over at least one wheel attached to a first side of the chassis and a second track which runs over at least one wheel attached to a second side of the chassis which together operate to move the apparatus from place to place. The or each track may be a continuous track. That is, the chassis of mobile aggregate washing apparatus may comprise a continuous track system preferably located towards the middle of the chassis, the continuous track system having a pair of driven, parallel tracks.

The aggregate scrubbing unit may be elongate and may be mounted lengthwise in an approximately central location along the chassis. The first screen unit may be mounted lengthwise along the chassis between the aggregate scrubbing unit and a first end of the chassis. The second screen unit may be mounted lengthwise along the chassis between the aggregate scrubbing unit and a second end of the chassis. This arrangement of the components of the mobile aggregate washing apparatus on the chassis results in a compact construction of the apparatus which is required in the transportation of the apparatus from place to place.

The aggregate scrubbing unit inlet may comprise a feed chute, preferably wherein said feed chute is hinged such that it can be folded over the inlet opening.

The aggregate scrubbing unit may comprise a log washer. The log washer may be a screw-type log washer. The screw-type log washer may comprise a first elongate screw comprising a first shaft and a first plurality of paddles attached along the first shaft and a second elongate screw comprising a second shaft and a second plurality of paddles attached along the second shaft. The screw-type log washer may be a coarse material screw-type log washer, which is suited for washing aggregates of size 0mm to 80mm.

The aggregate scrubbing unit, e.g., log washer, may comprise a housing having a roof and first and second side walls. The roof may comprise a roof ridge, a first roof portion sloping downwards from the ridge to the first side wall and a second roof portion sloping downwards from the ridge to the second side wall. The first roof portion may comprise at least one access door which opens by pivoting upwards towards the roof ridge. The second roof portion may comprise at least one access door which opens by pivoting upwards towards the roof ridge. The access door or doors have been designed to pivot upwards and provide optimum access to the inner workings of the aggregate scrubbing unit, e.g., log washer, while still retaining a low height to facilitate transportation of the washing apparatus from place to place by complying with height restrictions imposed by transport regulations in the United Kingdom and Europe.

In alternative embodiments of the invention, the aggregate scrubbing unit may comprise any of a barrel washer, a coarse material washer, a fines material washer.

The aggregate scrubbing unit may be mounted on the chassis via a support framework, the support framework preferably comprising a front support frame, a rear support frame, and, optionally, a mid support frame.

The mobile aggregate washing apparatus may comprise a water tank mounted on the chassis beneath the aggregate scrubbing unit. The water tank may be provided with one or more pumps and is also referred to herein as a sump tank.

The first screen unit may receive a first material discharged from a first end of the aggregate scrubbing unit. The first screen unit may comprise one or more sizing screen decks which separate the first material into differently-sized aggregate materials, for example, differently sized stones. The or each sizing screen deck may comprise a vibrating screen. The or each sizing screen deck may comprise any of a linear motion screen, a circular motion screen, an elliptical motion screen. The first screen unit may comprise one or more water sprays which wash the first material from the aggregate scrubbing unit. The first screen unit may comprise a screen chute for conveying material away from the first screen unit.

The first screen unit may be mounted to a subframe slidably mounted to the chassis. In this embodiment, the subframe is preferably mounted to the chassis in a first position for transport and in an alternate, second position when the apparatus is in working mode, particularly preferably wherein the subframe is mounted to the chassis by pinning with one or more bolts or pins.

The first screen unit may comprise a sizing screen deck which is operable to receive the first material from the aggregate scrubbing unit and separate the first material into two differently-sized aggregate materials. The mobile aggregate washing apparatus may comprise first and second aggregate conveyors which convey the two differently- sized aggregate materials away from the apparatus. The first and second aggregate conveyors may be attached to the chassis and protrude from a first end of the chassis and either a first or second side of the chassis.

The first screen unit may comprise a first sizing screen deck which is operable to receive the first material from the aggregate scrubbing unit and a second sizing screen deck which together separate the first material into three differently-sized aggregate materials. The second sizing screen deck may be located beneath the first sizing screen deck between the first sizing screen deck and the chassis.

The mobile aggregate washing apparatus may comprise first, second and third aggregate conveyors which convey the three differently-sized aggregate materials away from the apparatus. The first, second and third aggregate conveyors may be attached to the chassis and protrude from a first end of the chassis and first and second sides of the chassis. Alternatively, the first aggregate conveyor may protrude from a first end of the chassis and the second and third aggregate conveyors from a first side of the chassis. This embodiment results in a decrease the footprint of the apparatus compared to having the second and third aggregate conveyors protruding from first and second sides and allows for the positioning of the apparatus against a wall. The second screen unit may receive a second material discharged from a second end of the aggregate scrubbing unit. The second screen unit may comprise one or more screen decks, e.g., dewatering screens, which separate the second material into trash, aggregate material and waste water. Each deck independently may be provided with a divider to split said deck in two.

The second screen unit may be mounted to a subframe slidably mounted to the chassis. In this embodiment, the subframe is preferably mounted to the chassis in a first position for transport and in an alternate, second position when the apparatus is in working mode, particularly preferably wherein the subframe is mounted to the chassis by pinning with one or more bolts or pins.

During use of the mobile washing apparatus, a receptacle, which does not form part of the apparatus, may be provided beneath the second screen unit for receiving trash.

The mobile washing apparatus may be provided with a chute for conveying trash away from the apparatus.

Preferably, a screw conveyor is located at the end of the second screen unit to push trash into a receptacle, such as a skip, placed, e.g., at the side of the washing apparatus. In this embodiment, an outlet chute may be placed between the screw conveyor and the receptacle.

The mobile washing apparatus may comprise a catch box for collecting waste water from the first or second screen unit, or both, preferably wherein said catch box is located underneath the second screen unit. Waste water is preferably directed via a conduit from the catch box into the sump tank.

The or each screen deck of the second screen unit may comprise a vibrating screen. The or each screen may comprise any of a linear motion screen, a circular motion screen, an elliptical motion screen.

The second screen unit may comprise a sizing screen which receives the second material and separates the second material into trash and an aggregate material/water mix. The mobile aggregate washing apparatus may comprise one or more sand conveyors which convey aggregate material, e.g., sand, from the second screen unit away from the apparatus. Whilst the sand conveyors are so named, the material they may convey is not considered to be limited to sand but to include any material

The or each sand conveyor independently is preferably attached to the chassis and protrudes from a second end of the chassis. The or each sand conveyor may be mounted to a turntable attached to the chassis such that the conveyor may be rotated away from the chassis centre, e.g., from about 15 to 45 degrees from the longitudinal axis of the apparatus such that, if two sand conveyors are present, they may be rotated such that they are at an angle of from about 30 to about 90 degrees to each other. In a preferred embodiment, the second screen unit has a split deck and two sand conveyors convey the aggregate material which passes through the second screen unit away from the apparatus, one conveyor for each side of the split deck.

In a particularly preferred embodiment, trash from the second screen unit drops into an outlet chute and is pushed by a screw conveyor towards a receptable such as a skip at the side of, but not forming part of the apparatus, with the waste water falling into a catch box located under the second screen unit and directed via a conduit back into the sump tank. The second screen unit may alternatively or additionally comprise a dewatering screen which receives and dewaters aggregate material/water mix. The dewatering screen may be located above a sizing screen. The mobile aggregate washing apparatus may comprise one or more conduits and pumps which move aggregate material/water mix from the catch box to the dewatering screen. The one or more conduits and pumps may move the aggregate material/water mix from the catch box via a water tank of the apparatus to the dewatering screen. The one or more conduits and pumps may move the aggregate material/water mix from the catch box via at least one aggregate separation unit of the apparatus to the dewatering screen. The 'double decker' arrangement of the sizing screen and the dewatering screen eliminates the need for using three vibrating screens in the processing of the material from the second end of the aggregate scrubbing unit. This significantly reduces the overall height of the mobile aggregate washing apparatus, which is important in transportation of the apparatus.

The mobile aggregate washing apparatus preferably comprises at least one lift unit for moving the aggregate scrubbing unit from a transport position upwards to an inclined working position and from the inclined working position downwards to the transport position, preferably wherein said lift unit is a powered lift unit.

Additionally, or alternatively, the mobile aggregate washing apparatus may comprise at least one lift unit for moving the first screen unit from a transport position upwards to a working position and from the working position downwards to the transport position.

Additionally, or alternatively, the mobile aggregate washing apparatus may comprise at least one lift unit for moving the second screen unit from a transport position upwards to a working position and from the working position downwards to the transport position.

In a preferred embodiment, the mobile aggregate washing apparatus comprises a plurality of lift units for moving each of the aggregate scrubbing unit, the first screen unit, and the second screen unit independently. Each lift unit independently is preferably mounted on the chassis of the apparatus.

The or each lift unit may independently comprise a hydraulic lift unit. However, this is not to be considered limiting and other means of effecting movement such as an electric actuator, mechanical jack, etc. may be used in addition to or instead of a hydraulic lift unit. The hydraulic lift units may comprise hydraulic control banks having levers that operate hydraulic cylinders in connection with components of the mobile aggregate washing apparatus so as to fold and unfold or push and retract one or more components of the apparatus. The conveyors of the mobile aggregate washing apparatus may comprise different widths and lengths. The conveyors are used for stockpiling or transfer of materials. Mounting the conveyors on the single chassis of the mobile aggregate washing apparatus eliminates the need for mounting them on to their own frames as separate pieces of equipment. Traditionally, in a static wash plant, these conveyors are separate pieces of equipment that need to be mounted on their own frames.

Each conveyor of the mobile aggregate washing apparatus independently is preferably a folding conveyor, that is the conveyor preferably comprises two or more sections which move, e.g., swing or pivot, with respect to each other such that the conveyor may be folded over itself for transport or storage, or both, particularly preferably wherein the conveyor further comprises a fold linkage for powering this action, i.e., for unfolding of the conveyor, folding of the conveyor, or both. For example, the conveyor preferably comprises at least a head section and a tail section and, when unfolded, is designed to carry bulk material along an elevating path from a low position adjacent the tail section, to a higher position adjacent the head section.

Each conveyor of the mobile aggregate washing apparatus independently may comprise a telescoping section, preferably wherein the conveyor is a folding conveyor with a telescoping section, e.g., a telescoping head section.

The mobile aggregate washing apparatus may comprise an aggregate separation unit mounted on the chassis of the apparatus. The aggregate separation unit may comprise at least one cyclone tower. The aggregate separation unit, e.g., cyclone tower, may receive aggregate/water mix from the second screen unit. The aggregate separation unit, e.g., cyclone tower, may receive aggregate/water mix from the second screen unit, e.g., from the catch box of the second screen unit via a sump tank of the apparatus, preferably by operation of one or more conduits and pumps of the apparatus. At least one pump may comprise a centrifugal pump.

The aggregate separation unit, e.g., cyclone tower, may separate aggregate particles according to their relative settling rate in a centrifugal force created inside the tower. Coarser aggregate particles and water may spiral down the cyclone tower and be discharged onto the dewatering screen of the second screen unit. The coarser aggregate particles may comprise sand. Finer aggregate particles and water may be removed by suction through an overflow of the cyclone tower. The finer aggregate particles may comprise clay, waste and ultra-fine particles.

The mobile aggregate washing apparatus may comprise one or more metal removal units. The one or more metal removal units may comprise one or more belt magnets.

The mobile aggregate washing apparatus may comprise a plurality of jack legs mounted on locations around the chassis of the apparatus which support the apparatus when in situ. Preferably the jack legs are retractable for transport of the apparatus.

In a separate embodiment of the invention, the chassis of the mobile aggregate washing apparatus may comprise one or more trailers. This allows the apparatus to be split into two or more units capable of being assembled and dissembled, if required.

In another aspect, the invention provides a method for converting the washing apparatus described herein from an unfolded, working position to a folded, transport position, and vice versa, the method comprising the following steps: i) folding and retracting the first screen unit into the chassis, preferably wherein the first screen unit is mounted on a first subframe configured to slidably engage with the chassis, e.g., via guide rails or channels; ii) lowering the second screen unit into the chassis, preferably wherein the second screen unit is mounted on a second subframe configured to slidably engage with the chassis, e.g., via guide rails or channels; iii) lowering the aggregate separation unit from its working angle to a substantially horizontal position with respect to the chassis.

When in the transport position, the apparatus is ready to be tracked onto a transport trailer.

In the embodiment wherein a conveyor is located at a first end of the apparatus, the method may further comprise one or more of the following steps prior to step (i): a) swinging or pivoting a first aggregate conveyor located at a first end of the apparatus to create a space between the first screen unit and said conveyor, b) folding said first aggregate conveyor over itself.

Additionally, or alternatively, in the embodiment wherein the apparatus comprises one or more side conveyors, the method may further comprise one or more of the following steps prior to step (ii): c) folding the or each side conveyor over the space created by the lowering of the first screen unit and fastening the free end(s) of said folded side conveyor(s) on the opposite side of the chassis to which said conveyor is mounted; d) optionally folding and pulling up the tail sections of the side conveyors into the chassis.

Additionally, or alternatively, in the embodiment wherein the apparatus comprises an aggregate separation unit and one or more sand conveyors, the method may further comprise one or more of the following steps prior to step (iii): e) lowering the aggregate separation unit into the chassis; f) pivoting and/or folding the aggregate separation unit into the space created by the lowering of the second screen unit; g) optionally rotating the or each sand conveyor to align with the chassis centre; h) optionally retracting the or each sand conveyor to reduce its length; i) folding the or each sand conveyor over itself.

Additionally, or alternatively, in the embodiment wherein the apparatus comprises a plurality of jack legs the method may further comprise the following final step: j) retracting the jack legs.

The steps above may be performed in the opposite order for converting the washing apparatus described herein from a folded, transport position to an unfolded, working position. The scope of the present invention is not limited to just the preferred embodiments but includes all the plausible variants concerning the components and operating mechanism of the components of the apparatus.

Brief Description of Drawings

Certain preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 shows a plan view of a preferred mobile washing apparatus according to the invention in working mode;

Figure 2 is a side view of the apparatus of Figure 1 ;

Figure 3 is a perspective view of the apparatus of Figure 1

Figure 4 is a plan view of the apparatus of Figure 1 in transport mode;

Figure 5 is a side view of the apparatus of Figure 4;

Figure 6 is a perspective view of the apparatus of Figure 4;

Figure 7 is a perspective view of the apparatus of Figure 1 showing specific sections that either fold, unfold, push or retract to convert the apparatus from working to transport mode and vice versa;

Figure 8 is a side view showing the first stage during the folding of the swing tail aggregate conveyor of the apparatus of Figure 1 ;

Figure 9 is a perspective view of one end of the apparatus of Figure 1 during the folding of the swing tail aggregate conveyor;

Figure 10 is a perspective view of the apparatus shown in Figure 9 with external portions removed so that the interior is visible;

Figures 11 to 13 show side views of one end of the apparatus of Figure 1 during the folding of the swing tail aggregate conveyor;

Figure 14 sows the last stage during the folding of the swing tail aggregate conveyor of the apparatus of Figure 1 ;

Figures 15 shows the lowering of the first screen unit into the chassis of the apparatus of Figure 1 ;

Figures 16 to 20 show perspective views of the different stages during the folding of the side aggregate conveyors of the apparatus of Figure 1;

Figures 21a and 21b are enlarged views showing the final stages in the folding of the side aggregate conveyors of the apparatus of Figure 1 ; Figure 22 shows the lowering of the second screen unit into the chassis of the apparatus of Figure 1 ;

Figure 23 shows the folding of the cyclone tower of the apparatus of Figure 1 ;

Figure 24 shows the folding of the sand conveyors of the apparatus of Figure 1; Figures 25 shows the reduction of the angle of inclination of the log washer of the apparatus of Figure 1 ;

Figures 26 shows the lowering of the log washer of the apparatus of Figure 1 ; Figures 26a and 26b show enlarged views of the lowering of the log washer into the chassis of the apparatus of Figure 1 ; and

Figure 27 shows the retraction of the jack legs and feed chute of the apparatus of Figure 1 such that the apparatus is in transport mode.

Detailed Description

The invention will hereafter be more particularly described with reference to the accompanying drawings, which show the mobile aggregate washing apparatus by way of example only and where like reference numeral represent like parts and assemblies throughout the several views.

Referring to the drawings, Figures 1 to 3 show a preferred mobile aggregate washing apparatus according to one embodiment of the invention, generally referred to herein by reference numeral 100, in working mode. As shown in Figures 1 to 3, mobile aggregate washing apparatus 100 comprises a tracked chassis 14. Various components forming the apparatus 100 are mounted on chassis 14. In the preferred embodiment of the invention shown in the drawings, these components comprise aggregate scrubbing unit 1 with feed chute 13, aggregate screen 9, first, second and third aggregate conveyors 10, 11 , and 12, trash screen 3, two sand conveyors 4, cyclone tower 2, power unit 6 for operating a plurality of hydraulic lift units 8, 19, 21 , the lifts being for one or more of folding and unfolding, pushing and retracting a component of apparatus 100, sump tank 7, and a plurality of jack legs 5.

Mobile aggregate washing apparatus 100 operates to remove trash from aggregate. The aggregate may be virgin aggregate or used aggregate. In the embodiment shown in the Figures, aggregate scrubbing unit 1 comprises a log washer. It will be appreciated that other types of scrubbing unit may be used, such as any of a barrel washer, a coarse material washer, a fines material washer.

Optional walkway 90 is shown in Figures 1 to 3 and 7 but has been removed from the remaining Figures. This walkway may be bolted on after the machine has been transported and set up on site. Although not shown in the drawings, it is possible to remove one or more other components from the mobile aggregate washing apparatus or add one or more other components to it and still retain the benefits of the core invention of a mobile aggregate scrubbing unit which may be converted from a folded transport position to an unfolded working position and vice versa.

Mobile aggregate washing apparatus 100 having at least components 1 to 13 listed above mounted on chassis 14, which may be moved using the tracks, offers distinct advantages over the counterparts known in the art as individual components such as screen units, conveyors and cyclones need not be mounted on separate frames and the entire apparatus is capable of being transitioned from a working position to a transport position.

As can be seen from the Figures, log washer 1 is elongate and is mounted lengthwise in an approximately central location along chassis 14 of mobile aggregate washing apparatus 100. Aggregate screen 9 is mounted lengthwise along chassis 14 between a first end of log washer 1 and a first end of chassis 14. Cyclone tower 2 is mounted on chassis 14 in proximity to a second end of log washer 1. T rash screen 3 is mounted lengthwise along chassis 14 between aggregate separation unit 2 and a second end of chassis 14. This arrangement of the components of mobile aggregate washing apparatus 100 on chassis 14 results in a compact construction of the apparatus 100 which is required in the transportation of apparatus 100 from place to place.

Log washer 1 of the preferred embodiment shown in the drawings is a screw-type log washer having a first elongate screw (not shown) comprising a first shaft and a first plurality of paddles attached along the first shaft and a second elongate screw (not shown) comprising a second shaft and a second plurality of paddles attached along the second shaft. Log washer 1 may be a coarse material screw-type log washer, which is suited for washing aggregates of size 0mm to 80mm. Referring in particular to Figures 26 and 26a and b, log washer 1 is mounted on log washer support frame comprising front frame Q, mid frame G and rear frame H such that the log washer may be inclined at an angle to chassis 14. Safety pins P may be removed from positions M and L located on chassis 14 beside the running guides for the front and rear log washer support frames Q, G in order to permit the lowering of log washer 1 from its inclined working position to a horizontal position suitable for transport and inserted into respective positions N and K to lock front and rear log washer support frames Q, G in the transport position.

Referring in particular to Figures 2 to 8 and 22, log washer 1 comprises a housing 27 having a roof 29 and first and second side walls 31. The roof 29 comprises a roof ridge 35, a first roof portion 37 sloping downwards from the ridge 35 to the first side wall 31 and a second roof portion 39 sloping downwards from the ridge 35 to the second side wall (not shown). The first roof portion 37 comprises five access doors 41 which open by pivoting upwards towards the roof ridge 35. The second roof portion 39 comprises five access doors 43 which open by pivoting upwards towards the roof ridge 35. Access doors 41, 43 have been designed to pivot upwards and provide optimum access to the inner workings of log washer 1 while still retaining a shorter height to facilitate transportation of washing apparatus 100 from place to place.

Roof ridge 35 of housing 27 of log washer 1 comprises feed chute 13. Virgin or used aggregate to be washed is fed into feed chute 13, for example, from a conveyor (not shown) which is not part of mobile aggregate washing apparatus 100. The aggregate may first be screened, scalped or crushed before being fed into feed chute 13.

When in its working position on apparatus 100, a first end of log washer 1 is lifted using hydraulic lift unit 8, such that housing 27 of log washer 1 is at an angle with respect to chassis 14. The angle of housing 27 of log washer 1 to chassis 14 can range from, for example, about 1 to about 14 or 16 degrees, depending on the severity of the aggregate washing action required. In the preferred embodiment shown in the drawings, the angle of incline in working mode is from about 8 degrees to about 12 degrees, e.g., 9 degrees. However, this is not considered limiting and any suitable angle is considered to be encompassed by the invention. The aggregate is fed into feed chute 13 at a lower, second end of log washer 1. Log washer 1 comprises a plurality of sprayers (not shown) at the second end of housing 27, which spray water from sump tank 7 onto the aggregate. The action of the intermeshing paddles of the first and second elongate screws of log washer 1, together with material-on-material inter-particle interaction, act to scrub the aggregate and remove deleterious materials. The intermeshing paddles convey a scrubbed first material along the length of housing 27 to the first end of log washer 1 where it is discharged onto aggregate screen 9. The remaining second material is discharged from the second end of log washer 1 onto screen 3.

Aggregate screen 9 receives the first material discharged from the first end of log washer 1. In this embodiment, screen 9 comprises first and second sizing screens (not shown) which separate the first material into differently-sized aggregate materials. It will be appreciated that more or fewer screens may be used. The sizing screens are robust and typically manufactured in either a welded or a bolted design. Each sizing screen is a vibrating screen, comprising any of a linear motion screen, a circular motion screen, an elliptical motion screen. The first and second sizing screens are in a stacked arrangement, with the second sizing screen located beneath the first sizing screen between the first sizing screen and chassis 14 of aggregate washing apparatus 100. Screen 9 comprises a plurality of sprayers which spray water from sump tank 7 onto the first material received from log washer 1.

The first sizing screen of aggregate screen 9 receives the first material from log washer 1 and separates the first material into two differently-sized aggregate materials. Oversize aggregate material is discharged from the first sizing screen onto first aggregate conveyor 12, attached to chassis 14 and protruding from a first end of chassis 14, to be conveyed away from aggregate washing apparatus 100. Mid-size aggregate material and water passes through the first sizing screen onto the second sizing screen. The mid-size aggregate material is discharged from the second sizing screen onto second aggregate conveyor 10, attached to chassis 14 and protruding from a side of chassis 14, to be conveyed away from aggregate washing apparatus 100. Small-size aggregate material and water passes through the second sizing screen. The small-size aggregate material is discharged onto the third aggregate conveyor 11 , attached to chassis 14 and protruding from another side of chassis 14, to be conveyed away from aggregate washing apparatus 100. As shown in Figure 13, aggregate screen 9 is mounted to first subframe 18 which is slidably mounted to chassis 14 via rollers 70 in guide rails 17. Subframe 18 may be mounted to chassis 14 in a first position for transport (see Figure 15) and in an alternate, second position when the apparatus is in working mode (see, inter alia, Figures 2 and 13).

Trash screen 3 receives the second material discharged from the second end of log washer 1. Screen 3 comprises a sizing screen (not shown) and a dewatering screen (not shown) located above the sizing screen. The screens comprise vibrating screens, for example, any of a linear motion screen, a circular motion screen, an elliptical motion screen.

The sizing screen receives the second material from log washer 1 and separates this into trash and an aggregate material/water mix. A receptacle (not shown) is conventionally provided beneath the sizing screen, in use, which receives the trash from the sizing screen. The aggregate material/water mix which passes through the sizing screen is received in a catch box (not shown) of mobile aggregate washing apparatus 100. Apparatus 100 further comprises conduits and pumps (not shown) which move the aggregate material/water mix from the catch box to the dewatering screen, via sump tank 7 of apparatus 100 and the aggregate separation unit 2 of apparatus 100. Dewatered aggregate material, comprising mainly sand, is discharged from the dewatering screen onto sand conveyors 4 attached to chassis 14 and protruding from the second end of chassis 14, to be conveyed away from aggregate washing apparatus 100. Waste water falls into the catch box under screen 3 and flows via a pipe into sump tank 7.

As can be seen from Figures 20 and 22, trash screen 3 is mounted to a second subframe which is slidably mounted to chassis 14 via rollers in guide rails. The second subframe may be mounted to chassis 14 in a first position for transport (see Figure 22) and in an alternate, second position when the apparatus is in working mode (see, inter alia, Figures 2 and 20).

In the preferred embodiment shown in the drawings, the aggregate separation unit 2 comprises a cyclone tower mounted on chassis 14 of apparatus 100. Cyclone tower 2 receives the aggregate/water mix from the catch box of screen 3 via sump tank 7, by operation of various conduits and pumps (not shown) of the apparatus. Cyclone tower 2 separates aggregate particles in the aggregate/water mix according to their relative settling rate in a centrifugal force created inside tower 2. Coarser aggregate particles and water spiral down cyclone tower 2 and are discharged onto the dewatering screen of screen 3. The coarser aggregate particles may comprise mainly sand. Finer aggregate particles and water are removed by suction through an overflow of cyclone tower 2. The finer aggregate particles may comprise clay, waste and ultra-fine particles. The aggregate/water mix which passes through the sizing screen into the catch box of screen 3 may be cycled from the catch box, via sump tank 7 and cyclone tower 2 onto the dewatering screen several times, in order to remove as much water and finer aggregate particles from the mix as possible.

The jack legs 5 of mobile aggregate washing apparatus 100 are mounted on chassis 14 at various locations to support the apparatus 100 when in situ in a working environment.

Mobile aggregate washing apparatus 100 is capable of transitioning between an unfolded, working configuration (as shown in Figures 1 to 3 and 7) and a folded, transport configuration (as shown in Figures 4 to 6 and 27) and vice versa. Mobile aggregate washing apparatus 100 comprises a plurality of hydraulic lift units 8 mounted on chassis 14 of apparatus 100. It will be appreciated that at least some of the lift units 8 may comprise other types of lift unit, e.g., pneumatic lift units. The hydraulic lift units comprise hydraulic control banks having levers that operate hydraulic cylinders in connection with the components of mobile aggregate washing apparatus 100 so as to fold and unfold or push and retract the components of the apparatus 1.

Referring in particular to Figures 8 to 27, a preferred method for transitioning the washing apparatus or wash plant 100 from a working position to a transport position, i.e., from an unfolding configuration to a folding configuration is shown. To assist in this transition, there are eight or more hydraulic control banks situated around the apparatus 100. Each hydraulic control bank has levers that operate hydraulic cylinders on a specific part of the apparatus to either fold, unfold, push or retract a section or assembly (I) on the apparatus 100, according to Figure 7. The preferred method for transitioning a method for transitioning the washing apparatus or wash plant 100 from a working position to a transport position, i.e., from an unfolding configuration to a folding configuration comprises the following steps: - a) as shown in Figure 12, folding and retracting aggregate tail conveyor 12 located at a first end of the apparatus wherein hydraulic ram 21 associated with conveyor 12 extends, thereby causing conveyor 12 to first swing or pivot by a roller or slider (not shown) moving down guide channel 22 and creating a space 23 between screen chute 15 and conveyor 12, followed by folding conveyor 12 with extending hydraulic ram 21 and sliding of chassis guide channels 22 into space 23 created between screen chute 15 and conveyor 12 (see Figures 8 to 14); b) lowering aggregate screen 9 down into chassis 14 (see Figure 15) followed by the folding of each of left- and right-hand side conveyors 10, 11 , each made up of four sections with each section hinged and pivoted at an angle of 90 degrees to the central axis of the apparatus, over aggregate screen 9 (see Figures 16-20). To accomplish this, the user first removes prop leg pins A (see Figure 15) and then using hydraulic cylinders 21 operated through control bank lever located on chassis 14, extending/retracting the cylinders to fold conveyors 10, 11 over aggregate screen 9, followed by the fastening of the folded conveyors on the opposite side of the apparatus;

- c) subsequent to the folding of left- and right-hand side conveyors 10, 11 , folding and pulling up the tail sections B of conveyors 10,11 sauch that they are level with the underside of chassis 14 to avoid contact with a transport trailer (see Figures 21a and 21b). As shown in Figures 21a and 21b, to accomplish this, the user first removes respective prop leg pins C beside each side conveyor first pivot point using hydraulic cylinders 51 , lift each tail section B up and re-pin prop legs;

- d) lowering trash screen 3 as shown in Figure 22, located towards the rear of apparatus 100, on to a subframe using hydraulic cylinders operated through activating control bank lever located on chassis 14, followed by sliding down of the subframe with screen 3 inside on to channels located on the inside of chassis 14. To accomplish this, firstly, the user removes locking pins 80 before the subframe can slide or roll down on channels located on the inside of chassis 14. Once in position, the user replaces locking pins 80 to secure trash screen 3;

- e) as shown in Figure 23, allowing cyclone tower 2, located adjacent to trash screen 3, to fold over via hydraulic cylinders operated through control bank lever located on chassis 14. To facilitate this step, the user firstly removes fixing pins (not shown);

- f) folding sand conveyor 4, located at the rear of apparatus 100, using hydraulic cylinders operated through control bank lever located on chassis 14 whereby the hydraulic cylinders are located on each conveyor 4 as shown in Figure 24;

- g) as shown in Figure 25, lowering log washer 1, located centrally on apparatus 100, from its working angle of preferably about 9 degrees to a resting position over its front support Q and rear support H, by retracting hydraulic cylinders 8 operated through control bank lever located on chassis 14. As shown in Figures 26a and 26b, to accomplish this, the user will have to remove safety pins P from their positions M and L located on chassis 14 beside the running guides for the front and rear log washer support frames Q, G. This will allow the user to activate the four hydraulic cylinders 8 to lower log washer 1 down into transport position. Once down, the user can secure log washer 1 firstly by reinserting pins P into respective positions N and K on frame Q and G, respectively, thereby locking the front and rear log washer support frames; and h) retracting jack legs 5 followed by folding down or removing feed chute 13 on log washer 1 as shown in Figure 27; such that the washing apparatus or wash plant transits from its working position and becomes ready to be tracked on a transport trailer as a single unit chassis.

It is to be understood that the invention is not limited to the specific details described herein, which are given by way of examples only and various modifications and alterations are possible without departing from the scope of the invention as defined in the appended claims.