The present disclosure relates to an apparatus that employs a multiplicity of solid particles in the treatment of substrates. The present disclosure further relates to the operation of an apparatus for the treatment of substrates using solid particles.

Standard methods for domestic and industrial cleaning of textiles and fabrics involve aqueous cleaning. These methods generally involve aqueous submersion of fabrics followed by soil removal, aqueous soil suspension, and water rinsing.

However, it is recognised that there are advantages to having reduced water consumption. For example, reducing water consumption has the effect of reducing the amount of effluent water that needs to be treated or disposed of. Reducing the amount of water also lowers the energy requirements of the process, as less energy is needed to heat the water, and reduces the amount of detergent required to achieve a desired detergent concentration. On the other hand, it is known that better cleaning is achieved by having more water present in the drum of a washing machine. Therefore, there is a need to reduce the amount of water used in washing processes while still allowing efficient cleaning of the soiled substrate.

In the light of the challenges which are associated with aqueous washing processes, the present applicant has previously devised a new approach to the problem that allows the deficiencies demonstrated by the methods of the prior art to be mitigated or overcome. The method which is provided eliminates the requirement for the use of large volumes of water, but is still capable of providing an efficient means of cleaning and stain removal, whilst also yielding economic and environmental benefits.

Thus, in WO2007/128962 there is disclosed a method and formulation for cleaning a soiled substrate, the method comprising the treatment of the moistened substrate with a formulation comprising a multiplicity of polymeric particles, wherein the formulation is free of organic solvents. The substrate may be wetted so as to achieve a substrate to water ratio of from 1 :0.1 to 1 :5 w/w, and optionally, the formulation additionally comprises at least one cleaning material, which typically comprises a surfactant, which preferably has detergent properties. In the disclosed embodiments, the substrate comprises a textile fibre. The polymeric particles may, for example, comprise particles of polyamides, polyesters, polyalkenes, polyurethanes or their copolymers, a particular example being nylon beads.

The use of this cleaning method, however, presents a requirement for the nylon beads to be efficiently separated from the cleaned substrate at the conclusion of the cleaning operation. This issue was addressed in WO2010/094959, which provides cleaning apparatus requiring the use of two internal drums capable of independent rotation, and which finds application in both industrial and domestic cleaning processes.

With a view to providing a simpler, more economical means for addressing the problem of efficient separation of the cleaning beads from the substrate at the conclusion of the cleaning process, a further apparatus is disclosed in WO201 1/064581. The apparatus of WO201 1/064581 , which finds application in both industrial and domestic cleaning processes, comprises a perforated drum and a removable outer drum skin which is adapted to prevent the ingress or egress of fluids and solid particulate matter from the interior of the drum. The cleaning method requires attachment of the outer skin to the drum during a first wash cycle, after which the skin is removed prior to operating a second wash cycle, following which the cleaned substrate is removed from the drum. The apparatus and method of WO201 1/064581 is extremely effective in successfully cleaning substrates, but the requirement for the attachment and removal of the outer skin detracts from the overall efficiency of the process. By providing for continuous circulation of the cleaning beads during the cleaning process, it was possible to dispense with the requirement for an outer skin.

Thus, in WO201 1/098815, there is provided an apparatus for use in the cleaning of soiled substrates, the apparatus comprising housing means having a first upper chamber with a rotatably mounted cylindrical cage mounted therein and a second lower chamber located beneath the cylindrical cage, and additionally comprising at least one recirculation means, access means, pumping means and a multiplicity of delivery means, wherein the rotatably mounted cylindrical cage comprises a drum having perforated side walls where up to 60% of the surface area of the side walls comprises perforations comprising holes having a diameter of no greater than 25.0 mm.

The apparatus of WO201 1/098815 is used for the cleaning of soiled substrates by methods which comprise the treatment of the substrates with formulations comprising solid particulate cleaning material and wash water, the methods typically comprising the steps of:

(a) introducing solid particulate cleaning material and water into the lower chamber of the apparatus;

(b) agitating and heating the solid particulate cleaning material and water;

(c) loading at least one soiled substrate into the rotatably mounted cylindrical cage via the access means;

(d) closing the access means so as to provide a substantially sealed system;

(e) introducing the solid particulate cleaning material and water into the rotatably mounted cylindrical cage;

(f) operating the apparatus for a wash cycle, wherein the rotatably mounted cylindrical cage is caused to rotate and wherein fluids and solid particulate cleaning material are caused to fall through perforations in the rotatably mounted cylindrical cage into the lower chamber in a controlled manner;

(g) operating the pumping means so as to transfer fresh solid particulate cleaning material and recycle used solid particulate cleaning material to separating means;

(h) operating control means so as to add the fresh and recycled solid particulate cleaning material to the rotatably mounted cylindrical cage in a controlled manner; and

(i) continuing with steps (f), (g) and (h) as required to effect cleaning of the soiled substrate.

The apparatus of WO201 1/098815 includes features to introduce solid particulate cleaning material into the rotatably mounted cylindrical cage and also comprises at least one recirculation means to facilitate recirculation of the solid particulate material for its re-use in cleaning operations. In addition, the apparatus of WO201 1/098815 can include ducting comprising separating means for separating the solid particulate material from water and control means adapted to control entry of the solid particulate material into the cylindrical cage. In one disclosed embodiment, the separating means comprises a rigid filter material such as wire mesh located in a receptor vessel above the cylindrical cage, and the control means comprises a valve located in feeder means, preferably in the form of a feed tube attached to the receptor vessel, and connected to the cage.

Although the apparatus disclosed in WO201 1/098815 provided considerable improvements for the cleaning of soiled substrates with formulations comprising solid particulate cleaning material and wash water, there remain problems in separating the solid particulate material from water prior to the use and re-use of the solid particulate material in the cleaning operation. In particular, separation of the solid particulate material from the apparatus in WO201 1/098815 is carried out using a separation vessel located above the cylindrical cage. Placement of the separating device in this position was considered to be necessary to allow the solid particulate material, in the form of beads, to fall under gravity to the filter material before entering the cylindrical cage. In order to recirculate, the solid particulate material was pumped along a recirculation path that extends from the sump located in the lower chamber of the apparatus to the separating vessel above the cylindrical cage.

A long recirculation path for the solid particulate material detrimentally impacts the efficiency of the apparatus as more energy is expended for pumping and a larger pump may be required to transport the solid particulate material along the recirculation path. Furthermore, as beads are pumped in combination with water along the recirculation path, then a relatively longer recirculation path is associated with relatively greater water usage within the apparatus because of the relatively greater total volume of water required for recirculation. In addition, the inclusion of a separating vessel above the cylindrical cage adversely increases the size of the apparatus, considerations that are particularly important for domestic washing machines.

The apparatus of WO2015/049544 addressed some of the deficiencies of the apparatus and method disclosed in WO2011/098815. In the apparatus of WO2015/049544, the door for providing access to the rotatably mounted drum of the cleaning apparatus is a door comprising a flow pathway for wash liquor and a multiplicity of solid particles and a separator. The separator is arranged to direct the multiplicity of solid particles from the flow pathway into the drum and the separator is further arranged to direct a portion of the wash liquor from the flow pathway to a location other than into the drum. In this way, the size of the cleaning apparatus was reduced by providing the separator as part of the door.

It is an object of the present disclosure to provide an improved apparatus and method for the cleaning of soiled substrates with solid particulate material. In particular, it is an object of the present disclosure to provide an improved apparatus and method for separating solid particulate material and water prior to the introduction of the solid particulate material in the cleaning operation. Improved separation of solid particulate material and water results in drier beads being used in the cleaning operation. It is a further object to provide an improved apparatus and method for cleaning soiled substrates with solid particulate material, which exhibit improved cleaning performance and/or which reduce water and energy consumption thereby improving the efficiency and economy of the apparatus and method. The inventors have surprisingly found that drier beads are able to provide improved cleaning performance.

According to a first aspect of the present disclosure there is provided an apparatus for use in the treatment of at least one substrate with a multiplicity of solid particles comprising:

a) a housing in which a drum is rotatably mounted;

b) a door moveable between an open position wherein the at least one substrate can be placed in the drum and a closed position wherein the apparatus is substantially sealed; c) a separator mounted in the door, wherein the separator comprises a perforated portion; d) a flow pathway pipe mounted on or in the housing, wherein the flow pathway pipe comprises an outlet; and

e) pumping means configured to pump a treatment liquor and a multiplicity of solid particles from a first location through the flow pathway pipe and out of the outlet towards the separator;

wherein the separator is arranged to direct the multiplicity of solid particles into the drum and wherein the separator is further arranged to direct a portion of the treatment liquor to a location other than the drum; and

wherein the flow pathway pipe is not attached to the door.

The apparatus of the first aspect (and also of the second aspect described hereinbelow) is particularly suitable as a cleaning apparatus. Thus, the apparatus is particularly suitable as a cleaning apparatus for use in the cleaning of at least one soiled substrate, and in this embodiment said treatment liquor is suitably referred to as a wash liquor. The apparatus is also suitable more generally as an apparatus for treating a substrate with a multiplicity of solid particles, particularly wherein the substrate is an animal substrate (including skins, hides, pelts, leather and fleeces), and wherein the term "treating" includes colouring and tanning and associated tanning processes (including cleaning, curing beamhouse treatments including soaking, liming, unhairing, scudding, fleshing, deliming, bating, pickling and fat-liquoring, enzyme treatment and dye-fixing), as described in more detail in the applicant's patent applications published as WO-2014/167358-A, WO-2014/167359-A and WO-2014/167360-A and the disclosure of those processes is incorporated herein by reference. A treating process further includes finishing, dyeing, softening or stonewashing processes, particularly wherein the substrate is a textile or garment. The apparatus of the first and second aspects and the associated method are described hereinbelow with reference to a cleaning apparatus for cleaning soiled substrate(s) wherein the treatment liquor is wash liquor, but it will be appreciated that the following disclosure, particularly of the apparatus and all features thereof, is also applicable to the more general use of the apparatus for treating a substrate with a multiplicity of solid particles.

As used throughout the description in relation to all the aspects disclosed herein, "wash liquor" is a liquid used in the cleaning apparatus. Preferably, the wash liquor is an aqueous medium. The aqueous medium may comprise or consist of water. The aqueous medium may be water

combined with at least one cleaning agent, such as a detergent composition and/or any further additives as detailed below.

As used throughout the description in relation to all the aspects disclosed herein, the "flow pathway pipe" is a route from the first location to the vicinity of the separator. The flow pathway pipe comprises an outlet. The solid particles and the wash liquor leave the flow pathway pipe through the outlet. The flow pathway may be a duct.

The flow pathway pipe preferably comprises a main portion and a nozzle portion, in which case the outlet is comprised in the nozzle portion. The main portion of the flow pathway pipe extends from the pumping means adjacent or comprised in the first location to the nozzle portion, and the nozzle portion is the portion of the flow pathway pipe that directs the wash liquor and the solid particles towards the separator.

The shape of the outlet is defined by the ends of the walls of the flow pathway pipe or, where present, the ends of the walls of the nozzle portion. The shape of the outlet may be planar, i.e. the ends of the walls of the flow pathway pipe or, where present, the ends of the walls of the nozzle portion, define a plane. Said plane may be perpendicular to the direction of flow of the solid particles and wash liquor through the outlet, or said plane may be inclined (typically by an angle of no more than about 50°) to the perpendicular direction relative to the direction of flow of the solid particles and wash liquor through the outlet.

As used herein, the term "perimeter of the outlet" describes a continuous line which defines the shape of the outlet. The perimeter may be rectilinear or curvilinear or a combination of rectilinear and curvilinear. The perimeter may be two-dimensional or three-dimensional. Thus, where the shape of the outlet defines a plane, the perimeter is two dimensional. Where the shape of the outlet defines multiple planes, or is non-planar or comprises non-planar sections (for instance, curves), then the perimeter is three-dimensional.

In the first aspect, no portion of the flow pathway pipe is attached to the door. As such, when the door is moved between the closed and open positions, the flow pathway pipe does not move. The flow pathway pipe is not affected by the opening and closing of the door. By having the separator mounted in the door and the flow pathway pipe mounted in the housing, the act of moving the door between the open position and the closed position does not require there to be separable portions of the flow pathway pipe. Advantageously, this also overcomes the problems associated with

having to provide adequate sealing and re-sealing between separable portions of the flow pathway pipe each time the door is opened and closed.

The outlet is oriented such that the solid particles and the wash liquor are directed towards the separator on leaving the flow pathway pipe, and preferably towards the perforated portion of the separator, preferably such that the initial contact of solid particles and wash liquor leaving the flow pathway pipe with the separator is with the perforated portion of the separator. Typically, the perimeter of the outlet is located no more than 30 mm from the perforated portion of the separator. Typically, the perimeter of the outlet is located no more than 12 mm, preferably no more than 10 mm, preferably no more than 8 mm, more preferably no more than 6 mm, preferably no more than 4 mm from the perforated portion of the separator. The minimum distance between the perimeter of the outlet and the perforated portion of the separator is dictated by the size of the solid particles being used, such that said minimum distance is greater than the largest dimension of the solid particles. Typically, the distance between the perimeter of the outlet and the perforated portion of the separator is no more than 24 mm, preferably no more than 6 mm, preferably no more than 4mm larger than the largest dimension of the solid particles. Preferably, the distance between the perimeter of the outlet and the perforated portion of the separator is no more than 2 mm, preferably no more than 1 mm larger than the largest dimension of the solid particles. Generally, the perimeter of the outlet is positioned at least 2 mm, preferably at least 3 mm from the perforated portion of the separator. Reducing the distance between the perimeter of the outlet of the flow pathway pipe and the perforated portion of the separator improves the ability of the separator to separate the solid particles from the wash liquor.

Preferably, the perimeter of the outlet is substantially equidistant from the perforated portion of the separator. As such, the distance between each point on the perimeter of the outlet and the nearest point of the perforated portion of the separator is substantially the same. Preferably the distance between any point on the perimeter of the outlet and the nearest point of the perforated portion of the separator varies by no more than ±2 mm, preferably by no more than ±1 mm, more preferably by no more than ±0.5 mm from the distance between any other point on the perimeter of the outlet and its nearest point of the perforated portion of the separator.

Where the perimeter of the outlet is not equidistant from the perforated portion of the separator, the outlet is oriented such that at least a portion of the perimeter (preferably at least 50%, preferably at least 70%) is at least a minimum distance away from the separator, wherein said minimum distance is greater than the largest dimension of the solid particles.

Preferably, the cross-sectional area of the outlet is smaller than the cross-sectional area of the flow pathway pipe. By reducing the cross-sectional area of the outlet relative to the cross-sectional area of the flow pathway pipe, improved separation of the solid particles from the wash liquor is achieved.

As described in more detail below, it is preferred that the bore of the flow pathway pipe narrows as the flow pathway pipe approaches its outlet, and typically the narrowing of the bore of the flow pathway pipe occurs in the nozzle portion thereof, where present. Preferably, the bore of the flow pathway pipe narrows gradually in order to minimize turbulence in the flow of the wash liquor and solid particles being pumped through the flow pathway pipe. Where the flow pathway pipe comprises a nozzle portion and a main portion, the cross-sectional area of the main portion is preferably substantially constant along its length.

Without being bound by theory, it is believed that by having an arrangement where the cross-sectional area of the outlet is narrower than the cross-sectional area of the flow pathway pipe, the velocity of the solid particles and wash liquor leaving the outlet is increased. By increasing the velocity of the solid particles and wash liquor that impinge on the separator, improved separation of the solid particles from the wash liquor is achieved. Improved separation of the solid particles from the wash liquor results in drier solid particles being directed to the drum, which surprisingly allows for improved cleaning of the at least one soiled substrate. Improved separation of wash liquor from the solid particles allows the wash liquor to be returned to the first location more quickly than if it flowed through the substrate, reducing the amount of water required in the cleaning apparatus.

Typically, the cross-sectional area of the outlet is from about 10% to about 99% of the cross-sectional area of the flow pathway pipe. The cross-sectional area of the outlet may be from about 20% to about 95%, from about 30% to about 90%, from about 40% to about 80%, from about 50% to about 90%, from about 50% to about 70%, preferably from about 55% to about 60% of the cross-sectional area of the flow pathway pipe. Preferably, the cross-sectional area of the outlet may be from about 55% to about 65% of the cross-sectional area of the flow pathway pipe.

Where there is variation in cross-sectional area along the length of the flow pathway pipe, the % is calculated with respect to the largest cross-sectional area of the flow pathway pipe, and where the flow pathway pipe comprises a main portion and a nozzle portion, the % is calculated with respect to the largest cross-sectional area of the main portion of the flow pathway pipe.

At its largest point, the cross-sectional area of the flow pathway pipe may be from 1000 mm2 to 5000 mm2, preferably from 2000 mm2 to 4000 mm2, more preferably from 2500 mm2 to 3500 mm2. In a particular arrangement, the cross-sectional area of the flow pathway pipe is about 3170 mm2.

The cross-sectional area of the outlet may be from 1000 mm2 to 3000 mm2, preferably from 1000 mm2 to 2500 mm2, more preferably from 1500 mm2 to 2000 mm2. In a particular arrangement, the cross-sectional area of the outlet is about 2030 mm2. In an alternative particular arrangement, the cross-sectional area of the outlet is about 1870 mm2. In another alternative particular arrangement, the cross-sectional area of the outlet is about 1710 mm2.

Preferably, the velocity of the wash liquor and the solid particles at the outlet is about 150 cm/s or more, preferably from about 150 to about 400 cm/s, preferably from about 200 cm/s to about 350 cm/s, preferably from about 200 cm/s to about 300 cm/s, preferably from about 250 cm/s to about 275 cm/s. Having a relatively high velocity of the wash liquor and solid particles at the outlet leads to improved separation of the solid particles from the wash liquor. Improved separation of the solid particles from the wash liquor results in drier solid particles being directed to the drum, which surprisingly allows for improved cleaning of the at least one soiled substrate.

Preferably, the outlet has an elongate shape. The elongate shape has a length, L, and a width, W, and the ratio L:W of the elongate shape is typically greater than 2:1 , preferably greater than 3: 1 , more preferably greater than 5: 1 , and preferably no more than about 20: 1 , more preferably no more than about 15: 1 , more preferably no more than about 10: 1.

An elongate shaped outlet allows the wash liquor and solid particles to have maximum coverage on the perforated portion of the separator. In particular, where the perforated portion of the separator is curved, having an elongate shape aligned along a direction of the perforated portion that is orthogonal to the direction of the curve leads to maximum coverage of the wash liquor and solid particles on the perforated portion. Maximising the coverage allows the wash liquor and solid particles to pass over more apertures in the perforated portion, thus allowing more opportunities for the wash liquor to pass through the separator.

The elongate shape may be a lozenge, a rectangle, a shape that is essentially rectangular but has rounded corners, or an obround. Preferably, the elongate shape is rectangular. Alternatively, the shape is preferably an obround. An elongate shaped outlet allows the wash liquor and multiplicity of solid particles to have maximum coverage on the perforated portion of the separator.

When the elongate shape is a lozenge, length L is the distance between one pair of opposite vertices and width W is the distance between the other pair of opposite vertices.

Preferably, the flow pathway pipe has a substantially circular cross-section, and where the flow pathway pipe comprises a main portion and a nozzle portion, it is preferred that the main portion has a substantially circular cross-section. As such, when the outlet has an elongate shape, typically the outlet shape is different to the cross-sectional shape of the flow pathway pipe.

Preferably, the outlet is aligned so that length L is at an angle of about 20° or less, preferably about 10° or less, preferably about 5° or less, more preferably about 1 ° or less away from horizontal. Most preferably, the outlet is aligned so that length L is horizontal.

When the perforated portion is curved, preferably, the outlet is aligned so that length L is parallel to a direction of the perforated portion that is not curved and width W is aligned with a direction of the perforated portion that is curved. Having the elongate outlet essentially parallel to the perforated portion of the separator improves the separation of solid particles from the wash liquor.

In the first aspect, the separator is mounted in the door. This arrangement advantageously provides easy access to the separator, allowing the separator or the perforated portion thereof to be more easily cleaned. Advantageously, the separator or just the perforated portion of the separator may be removable. Thus, the improved apparatus of the present invention provides a separator and a perforated portion thereof which may be cleaned and maintained more readily and may be easily replaced if damaged. Furthermore, having the separator located in the door provides for a short path length for the wash liquor to return to the first location, which reduces the amount of water required in the cleaning apparatus. In addition, by locating the separator in the door, the return of wash liquor to the first location is faster.

According to a second aspect of the present disclosure there is provided an apparatus for use in the treatment of at least one substrate with a multiplicity of solid particles comprising:

a) a housing in which a drum is rotatably mounted;

b) a door moveable between an open position wherein the at least one substrate can be placed in the drum and a closed position wherein the apparatus is substantially sealed;

c) a separator, wherein the separator comprises a perforated portion;

d) a flow pathway pipe mounted on or in the housing, wherein the flow pathway pipe comprises an outlet; and

e) pumping means configured to pump a treatment liquor and a multiplicity of solid particles from a first location through a flow pathway pipe and out of the outlet towards the separator; wherein the separator is arranged to direct the multiplicity of solid particles into the drum and wherein the separator is further arranged to direct a portion of the treatment liquor to a location other than the drum; and

wherein at least one of the following conditions is fulfilled:

(i) the cross-sectional area of the outlet is smaller than the cross-sectional area of the flow pathway pipe;

(ii) the outlet has an elongate shape;

(iii) the perimeter of the outlet is located no more than 30 mm, preferably no more than 12 mm from the perforated portion of the separator;

(iv) the perimeter of the outlet is essentially equidistant from the perforated portion of the separator; and

(v) the velocity of the treatment liquor and the solid particles at the outlet is from about 150 cm/s or more.

The cleaning apparatus may fulfill conditions (i) and (ii). The cleaning apparatus may fulfill conditions (i) and (iii). The cleaning apparatus may fulfill conditions (i) and (iv). The cleaning apparatus may fulfill conditions (i) and (v). The cleaning apparatus may fulfill conditions (ii) and (iii). The cleaning apparatus may fulfill conditions (ii) and (iv). The cleaning apparatus may fulfill conditions (ii) and (v). The cleaning apparatus may fulfill conditions (iii) and (iv). The cleaning apparatus may fulfill conditions (iii) and (v). The cleaning apparatus may fulfill conditions (iv) and (v). The cleaning apparatus may fulfill conditions (i) and (ii) and (iii). The cleaning apparatus may fulfill conditions (i) and (ii) and (iv). The cleaning apparatus may fulfill conditions (i) and (ii) and (v). The cleaning apparatus may fulfill conditions (ii) and (iii) and (iv). The cleaning apparatus may fulfill conditions (ii) and (iii) and (v). The cleaning apparatus may fulfill conditions (iii) and (iv) and (v). The cleaning apparatus may fulfill conditions (i) and (ii) and (iii) and (iv). The cleaning apparatus may fulfill conditions (i) and (ii) and (iii) and (v). The cleaning apparatus may fulfill conditions (i) and (ii) and (iv) and (v). The cleaning apparatus may fulfill conditions (i) and (iii) and (iv) and (v). The cleaning apparatus may fulfill conditions (ii) and (iii) and (iv) and (v). Preferably, the cleaning apparatus fulfills all of conditions (i) to (iv).

The description hereinabove of the dimensions, shape, cross-sectional area, velocity, orientation and alignment of the outlet, and the dimensions, shape and cross-sectional area of the flow pathway pipe of the first aspect apply equally to the second aspect, and also to the other aspects described herein.

In the second aspect, it is preferred that no portion of the flow pathway pipe is mounted in the door, so that the act of moving the door between the open position and the closed position does not require separable and resealable portions of the flow pathway pipe. However, in an alternative arrangement, a part of the flow pathway pipe may be mounted in the door. In such an arrangement, when the door is in the open position, there are created two separate sections of the flow pathway pipe and in this arrangement the cleaning apparatus suitably comprises a seal adapted to provide a seal between the two separate sections of the flow pathway pipe when the door is in the closed position.

In the second aspect, the separator may be mounted in the door, as described hereinabove for the first aspect.

Alternatively, in the second aspect, the separator may be mounted in a location other than the door. For example, the separator may be located at the top of the housing, for instance alongside or above the drum. The separator may be located inside the housing. Alternatively, part of or the entire separator may be located external to the housing. When the separator is in a location other than in the door, the cleaning apparatus is suitably arranged so that the separator is able to direct the solid particles towards the drum via a pipe or duct. The apparatus may be arranged such that the solid particles may move from the separator towards the drum under gravity.

The separator may be retro-fitted to an existing apparatus.

In a third aspect of the present disclosure there is provided a method of treating at least one substrate comprising the treatment of the substrate with a multiplicity of solid particles using any of the apparatus defined herein.

Preferably, the method comprises the steps of:

(a) loading the at least one substrate into the drum and closing the door;

(b) introducing treatment liquor to moisten the substrate;

(c) rotating the drum;

(d) operating pumping means to pump treatment liquor and the multiplicity of solid particles from the first location through the flow pathway pipe towards the separator and introducing the multiplicity of solid particles into the drum via the separator.

The method preferably further comprises the step of (e) operating the apparatus for a treatment cycle wherein the treatment liquor and the multiplicity of solid particles are transferred from the drum into a lower portion of the housing as the drum rotates.

The method preferably further comprises the steps of (f) operating the pumping means so as to pump additional treatment liquor and solid particles from the first location to the separator and to recirculate the multiplicity of solid particles used in step (d) for re-use in the treatment operation; and (g) continuing with steps (c), (d), (e) and (f) as required to effect treatment of the at least one substrate.

The following features apply to each of the aspects of the disclosure described herein.

Preferably, the outlet is configured such that the path of the wash liquor and multiplicity of solid particles leaving the outlet defines an angle of incidence, angle λ as shown on Figure 7, on the surface of the separator (and preferably on the perforated portion of the separator, as described hereinabove) of from about 60° to about 120°, preferably from about 65° to about 115°, preferably from about 70° to about 110°, preferably from about 75° to about 105°, preferably from about 80° to about 100°, more preferably from about 85° to about 95°. Preferably, the outlet is configured such that the path of the wash liquor and multiplicity of solid particles leaving the outlet defines an angle of incidence, angle λ as shown on Figure 7, on the surface of the separator (and preferably on the perforated portion of the separator, as described hereinabove) of from about 60° to about 150°, preferably of from about 70° to about 150°, preferably from about 80° to about 140°, preferably from about 90° to about 130°. Most preferably, the wash liquor and multiplicity of solid particles are directed at an angle of incidence perpendicular or substantially perpendicular to the surface of the perforated portion of the separator on which it impinges. Having an angle of incidence that is perpendicular or substantially perpendicular improves the separation of solid particles from the wash liquor. As used herein, the term "substantially perpendicular" means ±5° to the perpendicular.

The perforated portion comprises a plurality of apertures. The perforated portion may be a web or mesh. Alternatively, the perforated portion may be a substrate having a plurality of apertures formed therein, i.e. wherein the apertures are created in an existing substrate (referred to herein as post-formed apertures). The apertures of the web or mesh and the apertures formed in a substrate are sized so as to permit the passage of wash liquor whilst preventing the passage of the multiplicity of solid particles. The apertures of the perforated portion may be any suitable shape, such as slots, circles or hexagons. Preferably the perforated portion has hexagonally shaped apertures.

The perforated portion may comprise a metal, an alloy, a polymer, a polymeric composite (such as a glass fibre reinforced polymer) or a ceramic. Preferably, the perforated portion comprises metal, more preferably stainless steel.

The perforated portion may be woven (such as a mesh formed from an interlaced network of wire or thread) or a substrate or plate with apertures formed therein (i.e. non-woven). Preferably the perforated portion is a metal plate with apertures formed therein. Having a metal plate with apertures formed therein generally reduces trapping of material compared with woven or mesh structures and allows for easier cleaning. Metal plates with apertures formed therein also suffer less from deformation and therefore require replacing less frequently.

In particular, the use of a metal plate having hexagonal apertures formed therein as the perforated portion leads to high levels of solid particle separation and, thus, drier beads returning to the drum. Furthermore, the use of a metal plate having hexagonal apertures formed therein is advantageous as it is durable and better able to withstand cleaning, in particular lint removal, without distorting aperture size or shape. A further advantage is that it is possible to form a separator entirely from the metal plate having hexagonal apertures without needing to include a support structure to maintain the shape of the separator. This is particularly advantageous when a curved separator is used in the cleaning apparatus.

The size of the apertures in the perforated portion of the separator depends on the size of the particles being used in the cleaning apparatus, such that the size of the apertures is smaller than the smallest dimension of the solid particles. Examples of suitable sizes for the apertures in the perforated portion include apertures having a length dimension in the region of from about 20 mm to about 40 mm and a width dimension in the region of from about 1.5 mm to about 3 mm. The perforated portion may have holes or apertures having a maximum dimension of from about 0.5 mm to about 4 mm, from about 1 mm to about 3 mm, from about 1.5 mm to about 2 mm, or from 0.5 mm to about 1 mm.

The total open area of the perforated portion of the separator (wherein the total open area is the total surface area of the apertures as a percentage of the total surface area of the perforated portion) is typically at least about 40%, at least about 45%, at least about 50%, at least about 55%, preferably at least about 60%. The total open area of the perforated portion of the separator is no more than about 99%, no more than about 90%, no more than about 80%, no more than about 75%, no more than about 70%, no more than about 65%. Preferably, the total open area is from about 45% to about 70%, preferably from about 60% to about 65%. .

Hexagonal apertures (measured across opposite sides) are typically about 2 mm to about 3 mm in width, preferably about 2.5 mm to about 3 mm. Particularly preferred hexagonal apertures have a width of about 2.85 mm.

An examples of a suitable material that can be used as the perforated portion of the separator includes those with about 12 holes per inch with 54.1 % open area or about 18 holes per inch with 53.7% open area.

A further example of a suitable material that can be used as the perforated portion of the separator is a stainless steel woven wire mesh having wire diameter of about 0.914 mm, aperture size of about 3.3 mm and open area of about 61.5%.

An example of a particularly preferred material that can be used as the perforated portion of the separator is a metal plate having hexagonal apertures of about 2.85 mm, a spacing of about 0.7 mm between apertures, an open area of about 64% and a material thickness of about 1.5 mm.

Advantageously, the perforated portion of the separator may also function as a lint filter. The presence of the perforated portion of the separator can obviate the need to have a separate lint filter in the cleaning apparatus. The arrangement of the separator in the door of the cleaning apparatus means that the separator may be accessed easily and the lint may be readily removed.

Where larger aperture sizes are selected, the ability to capture lint on the perforated portion of the separator generally reduces. Preferably, the apertures of the separator are small enough to capture lint and/or other unwanted fine particulate matter entrained in the wash liquor.

The perforated portion of the separator may be planar. Preferably, the perforated portion of the separator is curved. Having a curved perforated portion improves the separation of solid particles from the wash liquor. Having a curved perforated portion also aids transit of the solid particles across the separator and helps to prevent the solid particles from congregating or building up on the perforated portion of the separator, which otherwise might prevent wash liquor from being able to pass through the perforated portion. The perforated portion of the separator may comprise, for example, a circular curve, an ellipsoidal curve, a parabolic curve, a catenary curve, a curve where y=xn and n>1 , a trumpet-shaped curve, a daffodil-shaped curve or a J-shaped curve. Preferably, the perforated portion of the separator has a shape that assists the re-direction of the multiplicity of solid particles into the drum. Thus, the multiplicity of solid particles that are directed onto the separator follow a path that substantially corresponds to the curvature of the perforated portion of the separator.

Preferably, when the perforated portion is curved, it is curved only in one direction. Preferably, the perforated portion of the separator may comprise a curve having a radius of curvature of from about 100 mm to about 300 mm, more preferably from about 100 mm to about 200 mm. An example of a suitable separator has a perforated portion comprising a curve having a radius of curvature of about 160 mm. Preferably, the apparatus is arranged such that the outlet of the flow pathway pipe directs the wash liquor and the multiplicity of solid particles towards the concave surface of the curved perforated portion of the separator. In this arrangement, wash liquor passes through the perforated portion without substantially changing direction whereas the multiplicity of solid particles are caused to change direction as they follow the curvature of the separator towards the drum. This arrangement improves separation of wash liquor and solid particles.

The perforated portion of the separator is typically from about 5 cm to about 50 cm wide. The perforated portion of the separator is typically from about 10 cm to about 30 cm wide, preferably from about 15 cm to about 25 cm wide, more preferably from about 20 to about 25 cm wide. The length of the perforated portion of the separator, which is in the direction along which the wash liquor and solid particles travel after they strike the separator, is typically from about 10 cm to about 40 cm, preferably from about 15 cm to about 35 cm. When the separator is curved, it is preferably about 15 cm to about 25 cm wide and from about 15 cm to about 35 cm long.

Typically, the separator directs at least 1 %, preferably at least 10%, preferably at least 25%, preferably at least 40%, preferably at least 50%, preferably at least 70%, preferably at least 90%, preferably at least 95%, preferably at least 99% by mass of wash liquor, relative to the total mass of wash liquor leaving the outlet, so that the wash liquor does not enter the drum with the solid particles.

The entry of a restricted amount of wash liquor into said drum can advantageously facilitate moistening of the soiled substrates for the cleaning operation. Therefore, the separator may be arranged to direct no greater than 99% by mass of wash liquor to a location so as to not enter the drum with the solid particulate material. Thus, up to 1 % by mass of wash liquor may be permitted to enter the drum. Alternatively, the separator may be arranged to direct no greater than 90% by mass of wash liquor to a location so as to not enter the drum with the solid particles. Thus, up to 10% by mass of wash liquor may be permitted to enter the drum.

Preferably, the door comprises a transparent material. Preferably, the transparent material is arranged such that at least the perforated portion of the separator is visible from outside the cleaning apparatus. In this way, a user of the cleaning apparatus is readily able to observe whether maintenance, cleaning or replacement of the separator is required.

The door may be arranged such that it is substantially parallel to the front of the housing of the apparatus. Alternatively, the door may be arranged such that it is not parallel to the front of the housing of the apparatus. For example, an upper portion of the door may project out from the front of the housing further than a lower portion of the door. Having a door shaped in this way allows, for example, adequate space to locate a separator in the upper portion of the door in close proximity to the drum. The cleaning apparatus may have a collar or hood that projects out from the front face of the housing around part or all of the opening of the housing through which the drum is accessible. Typically, the door and the collar or hood are shaped so that when the door is closed, the door and the collar or hood cooperate to create a seal. There may be sealing means positioned between the door and the collar or hood.

The door suitably comprises a drain channel through which wash liquor that has passed through the separator may travel between an inner portion and an outer portion of the door and exit the door to a location other than the drum. Preferably, the location to which the separated wash liquor is directed is the first location. This arrangement provides a short path length through which the wash liquor passes in order to return to the first location. Having a short path length through which the wash liquor returns to the first location means that less water is needed to operate the cleaning apparatus, and hence a reduction in water consumption. A smaller water requirement is beneficial particularly in locations where there are water shortages. Furthermore, having a smaller water requirement means that less energy is needed to heat the water in the apparatus to the required temperature.

The apparatus suitably comprises a sump located in the housing. The first location referred to herein is preferably the sump.

The sump may comprise a first end proximate to the door and a second end distal to the door. The sump may comprise a sloping floor arranged to direct the solid particles to the second end. In this arrangement, the pumping means is preferably located proximate to the second end. Alternatively, the sump may comprise a sloping floor arranged to direct the solid particles to the first end. In this arrangement, the pumping means is preferably located proximate to the first end. Alternatively, the floor of the sump may be essentially horizontal. In this arrangement, the solid particles and water in the sump may be pumped from any point along the sump. In particular, a particularly preferred arrangement has the pump located to one side of the sump so that the flow pathway pipe may be positioned to pass up one side of the drum towards the separator.

The sump may comprise a bottom portion proximate a lower portion of the housing and a top portion proximate the drum. Preferably, the sump is shaped such that along the direction from the first end to the second end, the bottom portion is narrower than the top portion. Typically, the sump has a U-shaped cross section. Preferably, the bottom portion of the sump is from about 5 to about 25 cm wide, preferably from about 10 to about 20 cm wide, preferably from about 14 to 15 cm wide. If the width at the bottom portion of the sump is too small, the solid particles may bridge across the top of the sump and may not be picked up by wash liquor being pumped through the sump.

Preferably, the sump walls between the bottom portion and the top portion are inclined at an angle from horizontal of from about 24° to about 80°, preferably from about 24° to about 50°, more preferably from about 24° to about 35°, more preferably from about 24° to about 30°, more preferably from about 25° to about 30°, more preferably from about 27° to about 30°. As the angle of the walls increases away from horizontal, more solid particles falling into the sump are able to slide down the walls and occupy the region at the bottom of the sump. Having the solid particles reaching the region at the bottom of the pump means that more particles can be picked up within the wash liquor that is pumped through the sump. This helps to minimize the amount of water required in the cleaning apparatus. On the other hand, the bigger the angle is away from horizontal, the bigger the sump area needs to be, which means that the overall machine size needs to be larger, which may be undesirable. The ranges from about 25° to about 30° and from about 27° to about 30° are particularly preferred because these provide a balance between

maximizing the volume in the sump and the return of the solid particles without overly increasing the overall dimensions of the cleaning apparatus.

The housing suitably comprises a tub and the drum is suitably mounted within the tub. The sump may be formed from part of the tub.

The solid particles are preferably located in the sump prior to the start of the method of cleaning using the cleaning apparatus. In operation, water may be added to the solid particles in the sump. When a threshold or desired volume of water is present in the sump, the water and solid particles may be pumped towards the separator. During the wash cycle, water and/or one or more cleaning agents can be added from delivery means into the drum and ultimately any wash liquor can be transferred to the sump, for example, by moving through perforations in the walls of the drum. In this way, during the course of the wash cycle, the contents of the sump may comprise wash liquor and a multiplicity of solid particles.

The pumping means is suitably located in a lower portion of the housing. The pumping means may be located in or be connected to the first location, such as a sump. The sump may comprise pumping means. The pumping means is preferably located at an end of the sump nearest the door, which suitably provides for a short pumping path for the introduction of the solid particles into the drum.

The pumping means draws the wash liquor and solid particles from the first location, such as the sump along the flow pathway pipe. The flow pathway pipe may extend from the pump through the rear part of the housing or through the housing to one side of the drum and then over and across at least part of the upper portion of the drum towards the separator. When the separator is mounted in the door, the flow pathway pipe is configured so that it ends in the vicinity of the door.

Typically, an electronic controller is used to control the pumping means. The electronic controller comprises a processor and a memory comprising logical instructions that when executed by the processor cause the pumping means to pump the wash liquor and the multiplicity of solid particles.

The memory may also comprise logical instructions that when executed by the processor cause the drum to rotate such that the at least one soiled substrate describes an annular path whereby a central portion of the drum is not occupied by any soiled substrate. Preferably, the drum is caused to rotate at a G force of at least 1 , and preferably the G force is from about 1 to about 10. The drum may be caused to rotate in this way prior to the processor causing the pumping means to pump the wash liquor and the multiplicity of solid particles.

The cleaning apparatus is adapted to recirculate the wash liquor and the multiplicity of solid particles. Recirculation of the solid particles enables their re-use in the cleaning operation. The recirculation path suitably comprises the flow pathway pipe.

Claims

1. An apparatus for use in the treatment of at least one substrate with a multiplicity of solid particles comprising:

a) a housing in which a drum is rotatably mounted;

b) a door moveable between an open position wherein the at least one substrate can be placed in the drum and a closed position wherein the apparatus is substantially sealed; c) a separator mounted in the door, wherein the separator comprises a perforated portion; d) a flow pathway pipe mounted on or in the housing, wherein the flow pathway pipe comprises an outlet; and

e) pumping means configured to pump treatment liquor and a multiplicity of solid particles from a first location through the flow pathway pipe and out of the outlet towards the separator;

wherein the separator is arranged to direct the multiplicity of solid particles into the drum and wherein the separator is further arranged to direct a portion of the treatment liquor to a location other than the drum; and

wherein the flow pathway pipe is not attached to the door.

2. The apparatus of claim 1 wherein the cross-sectional area of the outlet is smaller than the cross-sectional area of the flow pathway pipe.

3. The apparatus of claim 2, wherein the cross-sectional area of the outlet is from about 10 to about 99% of the cross-sectional area of the flow pathway pipe.

4. The apparatus of claim 1 or claim 2, wherein the perimeter of the outlet is located no more than about 12 mm from the perforated portion of the separator, preferably no more than about 10 mm from the perforated portion of the separator.

5. The apparatus of any of the preceding claims, wherein the perimeter of the outlet is essentially equidistant from the perforated portion of the separator.

6. The apparatus of any of the preceding claims, wherein the outlet has an elongate shape, preferably the elongate shape has a length, L, and a width, W, such that the ratio L:W of the elongate shape is greater than 2: 1.

7. The apparatus of any of the preceding claims, wherein the velocity of the treatment liquor and the solid particles at the outlet is about 150 cm/s or more.

8. An apparatus for use in the treatment of at least one substrate with a multiplicity of solid particles comprising:

(a) a housing in which a drum is rotatably mounted;

(b) a door moveable between an open position wherein the at least one substrate can be placed in the drum and a closed position wherein the apparatus is substantially sealed;

(c) a separator, wherein the separator comprises a perforated portion;

(d) a flow pathway pipe mounted on or in the housing, wherein the flow pathway pipe comprises an outlet; and

(e) pumping means configured to pump treatment liquor and a multiplicity of solid particles from a first location through a flow pathway pipe and out of the outlet towards the separator; wherein the separator is arranged to direct the multiplicity of solid particles into the drum and wherein the separator is further arranged to direct a portion of the treatment liquor to a location other than the drum; and

wherein at least one of the following conditions is fulfilled:

(i) the cross-sectional area of the outlet is smaller than the cross-sectional area of the flow pathway pipe;

(ii) the outlet has an elongate shape;

(iii) the perimeter of the outlet is located no more than 30 mm, preferably no more than 12 mm from the perforated portion of the separator;

(iv) the perimeter of the outlet is essentially equidistant from the perforated portion of the separator;

(v) the velocity of the treatment liquor and the solid particles at the outlet is about 150 cm/s or more.

9. The apparatus of claim 8 wherein in condition (iii) the perimeter of the outlet is located no more than 12 mm from the perforated portion of the separator.

10. The apparatus of claim 8 or claim 9 wherein all of conditions (i) to (v) are fulfilled.

1 1. The apparatus of any of claims 8 to 10, wherein the cross-sectional area of the outlet is from about 10 to about 99% of the cross-sectional area of the flow pathway pipe.

12. The apparatus of any of claims 8 to 11 wherein the perimeter of the outlet is located no more than about 10 mm from the perforated portion of the separator.

13. The apparatus of any of claims 8 to 12, wherein the elongate shape has a length, L, and a width, W, such that the ratio L:W of the elongate shape is greater than 2: 1.

14. The apparatus of any of claims 8 to 13, wherein the separator is located in the door.

15. The apparatus of claim 14, wherein the flow pathway pipe is not attached to the door.

16. The apparatus of any of claims 8 to 13, wherein the separator is mounted in a location other than in the door.

17. The apparatus of any of the preceding claims, wherein the outlet is configured such that the path of the treatment liquor and multiplicity of solid particles leaving the outlet defines an angle of incidence, λ, on the surface of the perforated portion of the separator of from about 60° to about 150°, preferably of from about 60° to about 120°.

18. The apparatus of any of the preceding claims, wherein the perforated portion of the separator is curved.

19. The apparatus of any of the preceding claims, wherein the wetness of the solid particles directed by the separator towards the drum is 20wt% or less, preferably 15wt% or less, preferably 10wt% or less.

20. The apparatus of any preceding claim, wherein said location other than the drum is said first location, preferably wherein said first location is a sump.

21. The apparatus of any preceding claim wherein the bore of the flow pathway pipe narrows as the flow pathway pipe approaches its outlet, and preferably wherein the flow pathway pipe comprises a main portion and a nozzle portion and said narrowing of the bore of the flow pathway pipe occurs in the nozzle portion thereof preferably such that the cross- sectional area of the main portion is substantially constant along its length.

22. The apparatus of any of the preceding claims, wherein the apparatus is a cleaning apparatus for use in the cleaning of at least one soiled substrate, wherein said treatment liquor is a wash liquor.

23. The apparatus of any of claims 1 to 21 , wherein the apparatus is an apparatus for treating a substrate with a multiplicity of solid particles, wherein the substrate is an animal substrate selected from skins, hides, pelts, leather and fleeces, preferably wherein treating is colouring, tanning and associated tanning processes.

24. A method of treating at least one substrate comprising the treatment of the substrate with a multiplicity of solid particles using the apparatus of any of claims 1 to 23.

25. The method of claim 24 comprising the steps of:

(a) loading the at least one substrate into the drum and closing the door;

(b) introducing treatment liquor to moisten the substrate;

(c) rotating the drum;

(d) operating pumping means to pump treatment liquor and the multiplicity of solid particles from the first location through the flow pathway pipe towards the separator and introducing the multiplicity of solid particles into the drum via the separator.

26. The method of claim 25, further comprising the step of:

(e) operating the apparatus for a treatment cycle wherein the treatment liquor and the multiplicity of solid particles are transferred from the drum into a lower portion of the housing as the drum rotates.

27. The method of claim 26, further comprising the steps of:

(f) operating the pumping means so as to pump additional treatment liquor and solid particles from the first location to the separator and to recirculate the multiplicity of solid particles used in step (d) for re-use in the treatment operation; and

(g) continuing with steps (c), (d), (e) and (f) as required to effect treatment of the at least one substrate.

28. The method of any of claims 24 to 27, wherein the method of treating is a method of cleaning at least one soiled substrate and wherein the treatment liquor is a wash liquor.

29. The method of any of claims 24 to 28, wherein the method of treating is a method of treating a substrate with a multiplicity of solid particles, wherein the substrate is an animal substrate selected from skins, hides, pelts, leather and fleeces, preferably wherein treating is colouring, tanning and associated tanning processes.