This invention relates generally to a log washer, used for disintegrating, scrubbing and washing the faces of tough rocks, clay particles etc., thereby producing a material that is clean and easy to process and particularly, to an improved log washer having a tracked arrangement.

Background to the Invention

Typically, aggregates are materials commonly used in construction sub-bases, concrete production, drainage and utility schemes. They include mainly sand, gravel and crushed rock.

A log washer is a high energy unit designed to disintegrate and scrub the faces of tough rocks, clay particles etc. and produce a material that is clean and easy to process. It can process and classify both virgin as well as a variety of recycled aggregates and remove contaminates such as silt, clay particles and detritus materials to produce stockpiles of clean materials.

The strength and functioning of a log washer are governed mainly by its three aspects, namely the tub design, the shafts and the gearbox. The length of a log washer directly affects the retention time of the material being washed. Longer wash tubs provide significantly increased retention time, which can further be increased by modifying paddle design and working angles. The shafts of log washers are also available in a variety of diameters.

A log washer can either be a fine material screw washer type or a coarse material screw washer type. Fine Material Screw Washers are widely used for washing, classifying and dewatering solids material that as large as 10mm or smaller whereas coarse material screw washers are widely used for washing crushed stone, aggregates, wood particles and other hard ores that are larger than 5mm which contain soluble clays and dust coatings.

When selecting a log washer, the type of feed material is taken into consideration. The size and shape of the feed material can affect the capacity of a particular size unit of a log washer. This application derives priority from the United Kingdom patent application number 2103537.3, titled “Mobile Wash Plant” and filed on 15 ^th March 2021 in the name of Tyrone International Limited.

The earliest priority application relates to a fully functional, tracked, mobile wash plant or apparatus specifically designed to alleviate the drawbacks of static wash plants. The tracked mobile wash plant thus includes various components like log washer, vibrating screens, sand plant, conveyors, cyclone towers and sump tank etc. on a single mobile chassis. Such an arrangement helps to achieve full mobility of the set-up, has much quicker speed of installation and the ability to move and transport the plant easily. It is also more economical to install and operate than conventional static plants and does not require prior planning permission.

As also indicated in the specification of the earliest priority application, the various components comprising the tracked mobile wash plant according to the priority application can be aggregated to form the mobile wash plant unit as a whole as well as can be segregated from one another and exist as individual units, while still retaining the novel and inventive aspect within each component along with the associated benefits of the core invention.

Normally, height of a log washer is one of the major concerns while considering its movement and transport as an independent unit as well as a part of a washing apparatus or wash plant. A conventional log washer requires vibrating screens to be at a high level whereby there is material feeding into the top of the log washer from a pre-screen and out of the log washer onto a trash screen and an aggregate screen.

As a general practice, log washers sit at a slope, normally at angles between zero and 14 degrees, depending upon the severity of the washing action required. The slope of the log washer is so optimized that maximum washing is achieved while also maintaining low power consumption and wear and tear of parts of the washer. For the purpose of washing, log washers are equipped with heavy duty conveying paddles welded to the shafts. When two log shafts rotate in opposite directions, the paddles welded to the shafts overlap so as to get maximum scrubbing action. It is a therefore an object of the present invention to provide one such segregated component of the tracked mobile wash plant, i.e., an improved tracked log washer mounted on a chassis with a greatly reduced setup time.

The improved tracked log washer provides several advantages when compared to a static plant. The unit is mobile and can be moved on site easily to new a location or transported on a trailer anywhere. Since it is mobile and can hydraulically move into a transport configuration, there is less manpower, time and crane equipment needed for setup/transport.

Summary of the Invention

The present invention provides an improved tracked log washer for disintegrating, separating, scrubbing and washing hard rock ore, gravel, limestone and phosphate that have tough, plastic sticky clay contaminants as well as other contaminants from raw material aggregates.

Accordingly, a first aspect of the present invention is a tracked aggregate scrubbing apparatus comprising: a chassis provided with one or more tracks operable to move the apparatus from place to place; a log washer supporting framework mounted to the chassis, the framework comprising a rear log washer support frame, a front log washer support frame, a plurality of stabiliser jack legs and one or more lift arms; a log washer mounted on the chassis, the log washer having a tub body with an inlet for receiving aggregate material; and means for moving the log washer from a substantially horizontal position with respect to the chassis to an inclined position at an angle to the chassis and from the inclined position downwards to the substantially horizontal position.

The means for moving the log washer preferably comprises at least one lift unit which moves the log washer 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.

In a preferred embodiment, the means for moving the log washer comprises a plurality of hydraulic control banks including a plurality of hydraulic cylinders located around the supporting framework.

In a preferred embodiment, the log washer is a screw-type log washer comprising 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.

In a preferred embodiment, the log washer comprises a housing having a roof and first and second side walls, the roof comprises 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 comprises at least one access door which opens by pivoting upwards towards the roof ridge and the second roof portion comprises 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.

The log washer tub body may comprise a feed chute, preferably wherein said feed chute is hinged such that it can be folded over the inlet opening.

Optionally, in addition to the above components, the tracked aggregate scrubbing apparatus according to the invention may include a trash screen and a rear chassis trash screen support.

The trash screen may receive material discharged from the log washer. The trash screen unit may comprise one or more screen decks, e.g., dewatering screens, which separate the material into trash, aggregate material and waste water. Each deck independently may be provided with a divider to split said deck in two. The trash screen may be mounted to a subframe slidably mounted to the rear chassis trash screen support. In this embodiment, the subframe is preferably mounted to the rear chassis trash screen support 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 rear chassis trash screen support by pinning with one or more bolts or pins.

During use of the tracked aggregate scrubbing apparatus, a receptacle, which does not form part of the apparatus, may be provided beneath the trash screen for receiving trash.

The tracked aggregate scrubbing apparatus may be provided with a chute for conveying trash away from the apparatus.

The or each screen deck of the trash screen 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 trash screen unit may comprise a sizing screen which receives the material and separates the material into trash and an aggregate material/water mix.

Alternatively, or additionally, in addition to the above components, the tracked aggregate scrubbing apparatus according to the invention may include one or more of a sump tank, a water pump and hydro cyclone towers.

Preferably, the angle of inclination of the log washer tub body during working position is 9°.

Preferably, a log washer feed chute is located on the log washer tub body for receiving the aggregate material, particularly preferably wherein the log washer feed chute is located on a top face of the log washer tub body.

Advantageously, the log washer tub body includes access doors pivoted at the top of the tub body which open upwards and provide optimum access to the inner workings of the log washer while still retaining a shorter height to facilitate easy transport.

Advantageously, the log washer is capable of being retracted into a horizontal resting position from the inclined working position so as to enable and facilitate easy movement and transport of the same when not in use. Preferably, the tracked aggregate scrubbing apparatus is mounted on a single mobile chassis allowing easy transport of the entire apparatus as a single unit.

Preferably, the chassis comprises a trailer having at least two wheels over which a continuous track is run. There are preferably at least four stabilizing jack legs around the chassis for supporting the entire framework of the apparatus when in situ. However, this is not to be considered limiting and the apparatus may comprise more or fewer jack legs.

Preferably, there are four hydraulic control banks comprising four hydraulic cylinders located around the supporting framework of the tracked aggregate scrubbing apparatus.

Preferably, the or each hydraulic control bank has levers that operate the hydraulic cylinders so as to fold, unfold, push or retract the tracked log washer.

In another aspect of the invention, a method for transitioning the tracked aggregate scrubbing apparatus from an inclined working position to a retracted horizontal transport position is provided. Said method includes the following steps:

(a) lowering the log washer tub body from a working angle of preferably 9° to a horizontal level;

(b) securing the retracted log washer tub body in the horizontal position, preferably by pinning.

A preferred method includes the following steps:

(a) lowering of the trash screen first, when present as an optional component, using a number of hydraulic cylinders of the hydraulic control banks whereby the trash screen runs or slides into guide channels inside the chassis;

(b) activating the retracting hydraulic cylinders located on the chassis, to facilitate lowering of the log washer tub or body, by removing four safety pins located on the chassis as well as the two safety pins located on both sides of the log washer supporting framework; (c) lowering of the log washer tub or body angle from a working angle of preferably 9° to a horizontal level by using the activated retracting hydraulic cylinders and control bank levers located on the chassis;

(d) securing the retracted log washer tub or body in the horizontal position by re- inserting four pins at four locations on the chassis as well as two pins on both sides of the log washer supporting framework.

The scope of the present invention is not limited to just the preferred embodiments but includes all the plausible variants concerning the assembly and operating mechanism of different parts of the tracked aggregate scrubbing apparatus. Brief Description of Drawinos

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 is a perspective isometric view of a preferred tracked aggregate scrubbing apparatus according to the invention in working mode; Figure 2 is a side view of the tracked aggregate scrubbing apparatus of Figure 1 ;

Figure 3 is detailed view of the lifting and retracting means of the log washer in Figure 1 , including hydraulic cylinders, control bank levers and safety pins;

Figure 4 is a side view of an alternative preferred tracked aggregate scrubbing apparatus in working mode; Figure 5 is an isometric view of the tracked aggregate scrubbing apparatus of Figure 4;

Figure 6 is an isometric view of the tracked aggregate scrubbing apparatus of Figure 4 when in the retracted transport position;

Figure 7 is an isometric view of the tracked aggregate scrubbing apparatus of Figure 1 when in the retracted transport position; Figure 8 is a side view of the tracked aggregate scrubbing apparatus of Figure 7; and Figure 9 is a side view of the tracked aggregate scrubbing apparatus of Figure 6.

The invention will hereafter be more particularly described with reference to the accompanying drawings, which show an improved tracked log washer 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, 7 and 8 show a preferred tracked aggregate scrubbing apparatus according to one embodiment of the invention, generally referred to herein by reference numeral 100. Figures 4 to 6 and 9 shown an alternative preferred tracked aggregate scrubbing apparatus according to another embodiment of the invention, generally referred to herein by reference numeral 200.

As shown in the Figures, tracked log washer 100, 200 comprises a tracked chassis 7 onto which supporting framework 5 is mounted, framework 5 comprising a rear log washer support frame 11 , a front log washer support frame 12, a plurality of stabilizer jack legs 9 and lift arms F. A log washer tub body 1 is inclined at an angle to the supporting framework 5. Log washer feed chute 10 is located on a top face of the log washer tub body 1 for receiving aggregate material. Hydraulic control banks 13 for operating hydraulic cylinders F located around the supporting base framework control the lowering (retracting) and raising (lifting) of one or more different parts of apparatus 100, 200.

In addition to the above components, log washer 100 includes power unit 2, trash screen 3, sump tank 4, water pump 6, hydro cyclone towers 14 and rear chassis trash screen support 8.

Log washer 100, 200 having components mounted on tracked chassis 7 offers distinct advantages over the counterparts known in the art as 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 along chassis 7 of apparatus 100, 200. Log washer 1 of the preferred embodiments 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 Figure 3, log washer 1 is mounted on log washer support frame comprising front frame 11 rear frame 12 such that the log washer may be inclined at an angle to chassis 7. Safety pins P may be removed from positions M and L located on chassis 7 beside the running guides for the support frames 12, 5 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 E to lock log washer support frames 12, 5 in the transport position, and vice versa. Thus, the lifting and retracting of apparatus 100, 200 is facilitated using safety pins for fixing at or removing from position L as well as safety pins to be inserted into or removed from position N depending upon the need whether to retract or lift apparatus 100, 200, respectively.

Log washer tub body 1 comprises roof and first and second side walls. The roof comprises 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 (not shown) in the Figures. The first roof portion comprises five access doors which open by pivoting upwards towards the roof ridge. The second roof portion comprises five access doors which open by pivoting upwards towards the roof ridge. The access doors have been designed to pivot upwards and provide optimum access to the inner workings of the log washer while still retaining a shorter height to facilitate transportation of apparatus 100, 200 from place to place.

Roof ridge of housing of log washer tub body 1 is on the top face thereof and comprises feed chute 10. Virgin or used aggregate to be washed is fed into feed chute 10, for example, from a conveyor (not shown) which is not part of apparatus 100, 200. The aggregate may first be screened, scalped or crushed before being fed into feed chute 10. When in its working position on apparatus 100, a first end of log washer tub body 1 is lifted using hydraulic lift unit F, such that log washer tub body 1 is at an angle with respect to chassis 7. The angle of log washer tub body 1 to chassis 7 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 10 at a lower, second end of log washer tub body 1 . Log washer 1 comprises a plurality of sprayers (not shown) at the second end of the housing, which spray water from sump tank 4 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 the housing to the first end of log washer 1 where it is discharged. The remaining second material is discharged from the second end of log washer 1 , for example in apparatus 200 onto trash screen 3.

Trash screen 3 of apparatus 200 receives 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 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 apparatus 100. Tracked log washer 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 4 of apparatus 100 and hydrocyclone towers 14 of apparatus 100. Dewatered aggregate material, comprising mainly sand, is discharged from the dewatering screen. Waste water falls into the catch box (not shown) under screen 3 and flows via a pipe into sump tank 7. As can be seen from Figures 1 , 2, 7 and 8, trash screen 3 of apparatus 100 is mounted to a subframe which is slidably mounted to rear trash screen support 8 on chassis 7. The subframe may be mounted to rear trash screen support 8 in a first position for transport (see Figures 7 and 8) and in an alternate, second position when the apparatus is in working mode (see Figures 1 and 2).

The jack legs 9 are mounted on chassis 7 at various locations to support the tracked log washer 100, 200 when in situ in a working environment.

Tracked log washer 100 is capable of being retracted from an inclined working position to a horizontally levelled transport position. A method resulting in such a transition comprises the following steps:

(a) lowering of the trash screen 3 first using a number of hydraulic cylinders F of the hydraulic control banks 13 whereby the trash screen 3 runs or slides into guide channels inside the chassis 7;

(b) activating the retracting hydraulic cylinders F located on the chassis, to facilitate lowering of the log washer tub or body 1 , by removing four safety pins P located on the chassis 7 as well as the two safety pins K located on both sides of the log washer supporting framework 5;

(c) lowering of the log washer tub or body 1 angle from a working angle of preferably 9° to a horizontal level by using the activated retracting hydraulic cylinders F and control bank levers located on the chassis 7;

(d) securing the retracted log washer tub or body 1 in the horizontal position by re inserting four pins P at four locations on the chassis 7 as well as two pins K on both sides of the log washer supporting framework 5.

Tracked log washer 200 is capable of being retracted from an inclined working position to a horizontally levelled transport position. A method resulting in such a transition comprises the following steps:

(a) activating the retracting hydraulic cylinders F located on the chassis, to facilitate lowering of the log washer tub or body 1 , by removing four safety pins P located on the chassis 7 as well as the two safety pins K located on both sides of the log washer supporting framework 5;

(b) lowering of the log washer tub or body 1 angle from a working angle of preferably 9° to a horizontal level by using the activated retracting hydraulic cylinders F and control bank levers located on the chassis 7; and

(c) securing the retracted log washer tub or body 1 in the horizontal position by re inserting four pins P at four locations on the chassis 7 as well as two pins K on both sides of the log washer supporting framework 5.

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.