EP2257667A1

EP2257667A1 - Washer dryer

Info

Publication number: EP2257667A1
Application number: EP09725726A
Authority: EP
Inventors: Robert Hicklin; Gérard LENOTTE; Ranbir Padda; Marcel Gerben Prinsen; Tim Smith
Original assignee: Rhodia Operations SAS
Current assignee: Rhodia Operations SAS
Priority date: 2008-03-28
Filing date: 2009-03-06
Publication date: 2010-12-08
Anticipated expiration: 2029-03-06
Also published as: GB2458719B; CN102016154A; WO2009118236A1; GB2458719A; EP2257667B1; CN102016154B; GB0805669D0; GB0819131D0

Abstract

The present invention relates to an industrial combined washing and drying machined (1) that is capable of carrying out multiple sequential washing a nd drying cycles of fabric, the machine comprising (a) an industrial sized front loading drum washing machine (1), having a drum, a water supply unit (4), a detergent supply unit (5), a heater, a motor, for rotating the drum; (b) a drainage unit, having: a heating element for heating air to a required temperature; an entry chute (9), an air mover; and an exit chute (10) for removing air from the washing machine drum; and (c) a control system for controlling the washing of the fabric by the washing machine and the drying of the fabric by the exhaust dryer (3), such that multiple sequential cycles of washing and drying can be carried out under predetermined conditions. Use of that machine for the washing and drying of fabric treated with a flame retardant product.

Description

WASHER DRYER

The present invention relates to a washer dryer machine, in particular a washer dryer machine suitable for carrying out repeated sequential washing and drying cycles of the same fabric load.

Currently, industry testing relating to the washing of fabric samples prior to flammability testing will tend to carry out multiple washing cycles, e.g. 50 washing cycles, followed by a single, final drying cycle. The repeated washing cycles are carried out in a washing machine, with the final drying cycle being carried out in a separate dryer machine.

New legislation relating to the washing of fabric samples prior to flammability testing will be introduced during 2008 (ISO 15797). The new washing protocol specifies a wash procedure as being a wash cycle and intermediate drying cycle.

It wi ll therefore be necessary to provide test results after multiple sequential washing and drying cycles, such as 50 sequential washing a nd drying cycles, in an acceptable timeframe.

Accordingly, a given fabric sample load must be subjected to multiple sequential washing and drying cycles, such as a sequence of 50 wash-then- dry cycles, prior to being tested. The machine should ideally be able to ca rry out these multiple sequentia l wash-then-dry cycles on the given fabric sample load without interruption or intervention. The fabric sample load need only be unloaded from the machine after completion of all the multiple washing and drying cycles have been completed.

There is therefore a need for an industrial washing a nd drying machine that can ca rry out multiple sequential washing and drying cycles. Industrial washing machines have a smaller sized drum than industrial drying machines. For a load of 25kg a washing machine might have a drum volume of 228dm³. For drying, in contrast, the drum volume might be 518dm . Accordingly, there is a problem to achieve sufficient drying, to an industrial standard of 0% + 3%, in a drum that is sized for industrial washing as there is less space for drying the fabric.

However, if a drum sized for industrial drying were used, this would create too high a load on the bearings when such a drum size was used for washing. Additionally, it would be much less efficient in terms of water, energy and detergent usage.

There is therefore a need for a machine that can ca rry out multiple sequential washing a nd drying cycles whi lst avoiding these problems.

US 1 ,799,649 relates to a combined washer-dryer machine for commercial service. The machine includes a hot air passageway filled with hot coils. Air is drawn over these coi ls to heat it, and this heated air is then drawn into the drum towards the bottom of the d rum, through the drum apertures. The air exits out the drum towa rds the top of the drum, through the d rum apertures. The movement of the drying air is caused by a fan drawing the air through this path.

US 2004/0221474 relates to a combined washer-dryer machine for a commercial la und ry setting. This machine is designed to wash a nd then dry a commercial la undry load, such as hospital, nursing home or hotel bedding and towels. The machine has a common heat source for heating wash water and providing drying a ir. The heated d rying ai r is delivered into the drum towards the top of the drum, through the drum perforations, and exits out the dru m towa rds the bottom of the drum, through the drum perforations. The movement of the drying air is caused by an exhaust fan drawing the air through this path.

Although these prior art machines can wash and dry a large fabric load, they are designed for commercial laundry rather than for industrial use.

For industrial purposes, specific standards have to be met. One particular issue with industrial drying is that standards frequently require the drying must be to 0% + 3% moisture. Commercial laundry would not need to be dried to these stringent standards. Industrial drying standards may also require a very even drying across the fabric sample, which again is not a priority for commercial laundry.

Commercial laundry machines would not be designed to carry out multiple sequential washing and drying cycles for the same fabric load. Each fabric load, e.g. of bedding or towels, would have a single wash-dry cycle before being removed for use. It is only in the context of industrial washing and drying - to simulate the effect of washing and drying the fabric numerous times in use prior to assessing whether product characteristics such as flammability have been maintained to an adequate level - that multiple sequential wash-dry cycles of the same fabric load are required.

JP 2007-289558 relates to a washer-dryer machine, for particular use in household applications. The aim of this machine is to recycle the air that has been used to dry the fabric, via a compressor and heat radiator system. The machine does not allow the air to exit to the atmosphere.

This recycling system, where the moisture-laden air is kept within the machine rather than expelled to the atmosphere, would not be suitable for meeting the standards in the context of industrial drying where moisture levels of 0% and an even drying of the fabric sample may be required. The present invention provides, in a first aspect, an industrial combined washing and drying machine that is capable of carrying out multiple sequential washing and drying cycles of fabric, the machine comprising : a) an industrial sized front loading drum washing machine, having: i. a drum in which fabric can be washed, which is substantially cylinder-shaped and mounted so as to rotate around a substantially horizontal axis, wherein a plurality of through- holes, for the passage of water to and from the drum, are formed at the circumferential surface of the drum; ii. a water supply unit, for feeding into the drum a controlled amount of water for washing or rinsing; iii. a detergent supply unit, for feeding into the drum a detergent, in a dosed amount; iv. a heater, for heating the water to a predetermined temperature; v. a motor, for rotating the drum; vi. a drainage unit, for removing water from the drum; and vii. an inlet/outlet hole located in the front of the washing machine body, through which the fabric can be loaded into and unloaded from the drum, and an associated door for opening and closing entry into the drum via said hole; b) an exhaust dryer, having: i. a heating element for heating air to a required temperature; ii. an entry chute for providing heated air into the washing machine drum; iii. an air mover for moving the air heated by the heating element through the entry chute into the washing machine drum; and iv. an exit chute for removing air from the washing machine drum to the atmosphere via the plurality of through-holes in the circumferential surface of the drum; and c) a control system for controlling the washing of the fabric by the washing machine and the drying of the fabric by the exhaust dryer, such that multiple sequential cycles of washing and drying can be carried out under predetermined conditions.

In particular, the entry chute for providing the heated air into the cylinder- shaped washing machine drum may provide the air via an end of the cylinder-shaped washing drum. The cylinder-shaped washing machine drum has two circular-shaped ends, one at the front of the machine and one at the back. By providing the heated air through a chute from an end of the cylinder-shaped drum, more efficient and even drying can be achieved. A more effective "blast" of heated air can be provided in this way. The air flow path used - in via an end of the cylinder-shaped drum and out via the plurality of through-holes in the circumferential surface of the drum - provides an improved efficiency and evenness of drying.

The provision of heated air in the prior art, whereby the heated air enters the drum via the through-holes in the circumferential surface of the drum and also exits through these holes, does not provide for such effective and even drying. This is not necessarily a problem for commercial drying but effective and even drying is very important for meeting set standards in industrial drying.

The provision of heated air into the cylinder-shaped washing machine drum via an end of the cylinder-shaped washing drum may allow heated air to be provided in volumes that would not be possible in a machine where the heated air was provided via the through- holes and/or may allow heated air to be provided at speeds that would not be possible in a machine where the heated air was provided via the through-holes.

Suitable selection of the volume and/or speed of heated air provided into the drum may assist in ensuring fabric is dried to a required efficiency and evenness. The present invention therefore provides: an industrial combined washing and drying machine that is capable of ca rrying out multiple seq uentia l washing a nd drying cycles of the same fabric load, the machine comprising : a) an industrial sized front loading drum washing machine, having: i. a drum in which fabric can be washed, which is substantially cylinder-shaped and mounted so as to rotate around a substantially horizontal axis, wherein a plurality of through- holes, for the passage of water to and from the drum, are formed at the circumferential surface of the drum; ii. a water supply unit, for feeding into the drum a controlled amount of water for washing or rinsing; iii. a detergent supply unit, for feeding into the drum a detergent, in a dosed amount; iv. a heater, for heating the water to a predetermined temperature; v. a motor, for rotating the drum; vi. a drainage unit, for removing water from the drum; and vii. an inlet/outlet hole located in the front of the washing machine body, through which the fabric can be loaded into and unloaded from the drum, and an associated door for opening and closing entry into the drum via said hole; b) an exhaust dryer, having: i. a heating element for heating air to a required temperature; ii. an entry chute for providing heated air into the washing machine drum, wherein the entry chute provides the heated air via an end of the cylinder-shaped washing drum; iii. an air mover for moving the air heated by the heating element through the entry chute into the washing machine drum; and iv. an exit chute for removing air from the washing machine drum to the atmosphere via the plurality of through-holes in the circumferential surface of the drum; and c) a control system for controlling the washing of the fabric by the washing machine and the drying of the fabric by the exhaust dryer, such that multiple sequential cycles of washing and drying can be carried out under predetermined conditions.

Surprisingly, it has been found that by blowing hot air into the drum of an industrial washing machine, using an exhaust dryer, and removing the air via the through- holes in the drum, drying of the washed fabric to an industrial standard of 0% + 3% can be achieved, despite there being less space for drying the fabric in such a drum.

Preferably, the machine is sized such that it is ca pable of ca rrying out multiple sequential washing and dryi ng cycles of 1 5kg or more, such as 20kg or more, preferably 25kg or more, e.g. from 25 to 30kg, of fabric.

There is no requirement for any heated air to be provided into the washing machine drum via the through- holes in the circumferential surface of the drum. In one embodiment, no heated air is provided into washing machine drum via the through-holes in the circumferential surface of the drum. In another embodiment, some but not all of the heated air (such as 20% by volume or less, e.g. 10% by volume or less, such as 5% by volume or less, for example 1 % by volume or less) is provided into washing machine drum via the through- holes in the circumferential surface of the drum.

Preferably, 50% or more, by volume, of all the heated air provided into the washing machine drum is provided via an end of the cylinder-shaped washing drum, preferably 60% or more, such as 70% or more, 80% or more or 90% or more, by volume, of all the heated air provided into the washing machine drum is provided via an end of the cylinder-shaped washing drum. In one embodiment 95% or more, by volume, of all the heated air provided into the washing machine drum is provided via an end of the cylinder- shaped washing drum, most preferably 99% or more, by volume, such as 100%. Preferably, the entry chute provides the heated air into the washing machine drum through the front of the washing machine. In particular, the cylinder-shaped drum will have an open end at the front of the machine and it is therefore preferred that the entry chute provides the heated air into the washing machine drum via this open end at the front of the machine.

The entry chute may provide the heated air into the washing machine drum at any suitable angle, i.e. from 0° to 90° to the vertical, for example from 5° to 90° to the vertical. The angle at which the a ir is provided may be above the horizontal, equal to the horizonta l, or below the horizontal. Clearly if the ang le at which the a ir is provided is 90° to the vertical then this is equal to the horizontal rather than above or below the horizontal. All other angles within the range may be either above or below the horizontal.

In one embodiment, the entry chute may provide the heated air into the washing machine drum at an angle of from 5 to 45° to the vertical, such as from 10 to 40° to the vertica l, e.g. from 1 2.5 to 35° to the vertical, for example from 1 5 to 30° to the vertical, such as from 1 6 to 25° to the vertica l. I n one such embod i ment the a i r is provided at a n a ng le above the horizonta l.

I n another embodiment, the entry chute may provide the heated air into the washing machine drum at an angle of from 45 to 90° to the vertica l, such as from 60 to 90° to the vertica l, e.g. from 65 to 90° to the vertica l, for example from 70 to 90° to the vertical, such as from 80 to 90° to the vertical. I n one such embod iment the air is provided at an angle above the horizontal or equal to the horizonta l. The entry chute may provide air into the washing machine drum, via an end of the cylinder-shaped washing drum, through a hole in the washing machine body.

In one embodiment, this hole is a hole separate to the inlet/outlet hole. In such an embodiment the separate hole may, for example, be provided in the front of the washing machine body (for example it may be adjacent to the inlet/outlet hole, e.g. above or below or to the left or to the right of the inlet/outlet hole).

In another embodiment, this hole is the inlet/outlet hole located in the front of the washing machine body. In one such embodiment, it may be that the entry chute is a flexible air pipe, and the inlet/outlet hole through which the air is blown can be opened normally to load and unload the fabric. In another such embodiment, the entry chute may be a removable assembly which can be removed in order to allow loading and unloading of the fabric through the inlet/outlet hole.

In a most preferred embodiment, the inlet/outlet hole located in the front of the washing machine body is provided with an exterior wall around its circumference, extending outwardly from the washing machine to define an outer hole at its distal end. The associated door is suitably located at the distal end of said exterior wall, and opens and closes the outer hole at this distal end of the exterior wall.

In a such an embodiment, the entry chute may provide the heated air into the washing machine drum through this exterior wall (and then through the inlet/outlet hole into the cylinder-shaped washing drum). In particular, there may be a hole in the exterior wall through which heated air is provided from the entry chute. The entry chute may be formed integrally with the exterior wall or may be attached to the exterior wall. In another such embodiment, this exterior wall may be the entry chute.

The exterior wall may suitably extend outwardly from the front of the washing machine body by from 5cm to 40cm, preferably from 7cm to 30cm, such as from 8cm to 25cm, more preferably from 10cm to 20cm.

In a preferred embodiment, the inlet/outlet hole is circular. Preferably, the outer hole at the distal end of the exterior wall is circular.

In a preferred embodiment, the exterior wall has an interior surface that includes an angled portion that angles downwardly in the direction of the drum. This angled portion is preferably present in at least the bottom fifth of the exterior wall, such as in at least the bottom quarter of the exterior wall. This angled portion is advantageous as it prevents the fabric sticki ng in the exterior wall/door area during dryi ng.

The a ngled portion is preferably at a n angle of 5° or more below the horizontal, such as 10° or more below the horizontal, e.g. 1 2° or more below the horizontal, preferably 1 5° or more below the horizontal, such as 1 8° or more below the horizontal, e.g. 20° or more below the horizontal.

The drum of the washing machine may be any suitable size, depending on the intended load. The drum of the washing machine may, for example, have a diameter of from 400mm to 2000mm, preferably from 500mm to 1500mm, e.g. from 600mm to 1200mm, such as from 700mm to 1000mm. The drum of the washing machine may, for example, have a depth of from 200mm to 1500mm, preferably from 250mm to 1000mm, such as from 300mm to 800mm, e.g. from 400mm to 600mm.

Preferably, the air mover is a fan or pump. In one embodiment, the heated air is moved through the entry chute into the drum at a speed of from 10 to 30m/s, e.g. from 12 to 25m/s, preferably from 13 to 20m/s, more preferably from 15 to 18m/s, such as from 16 to 17 m/s.

In one embodiment, the entry chute has an end that feeds the air into the drum having an area of 0.001m² or more, preferably 0.005m² or more, such as 0.01m² or more, e.g. from 0.015m² or more, such as 0.02m² or more.

In one embodiment, the entry chute has an end that feeds the air into the drum having an area of from 0.005 to 0.1m², preferably from 0.01 to 0.05m², such as from 0.02 to 0.04m², e.g. from 0.030 to 0.035m².

The entry chute has an end that feeds the air into the drum having any suitable shape, such as an oval or circular shape or a rectangular or square shape. Preferably, the end is rectangular in shape.

In one embodiment, the speed of the heated air and the size of the chute are selected so that the air flow is from 1500 to 2500m³/h, e.g. from 1750 to 2250m³/h, preferably from 1800 to 2200m³/h, such as from 1900 to 2100m³/h, e.g. about 2000m³ /h.

Preferably, the entry chute feeds air into the drum at an angle of 5° or more to the vertical, such as 10° or more to the vertical, e.g. 12.5° or more to the vertical, preferably 15° or more to the vertical, such as 16° or more to the vertical.

The machine is suitably provided with a sensor that directly or indirectly ascertains the water levels inside the drum.

In a preferred embodiment, the machine is provided with a sensor that measures the water level within the air passing through the exit chute. This may be used to ascertain the water levels inside the drum. For example, a water level of 2% in the air in the exit chute corresponds to a water level of 0% in the fabric in the drum.

Preferably, the sensor that directly or indirectly ascertains the water level inside the drum provides feedback to the control system, so that the control system can determine when the drying cycle can finish.

This can provide for a more efficient machine, as the drying cycle can be allowed to last only as long as is necessary to achieve the desired dryness level. Equally, it can ensure that a drying cycle is not carried out for a period of time that is insufficient to achieve the desired dryness level. Prior art systems, e.g. in US2004/0221474, determine the drying time prior to commencing the drying cycle - there is no monitoring of the moisture levels in the air exiting the machine to ascertain the progress of the drying cycle and permit adjustments of the conditions (e.g. the length of the drying cycle, or the temperature of the heated air, or the speed of the heated air) to be made accordingly.

The through- holes at the circumferential surface of the drum, through which water passes to and from the drum, and through which air can flow from the drum into the exit chute during drying cycles, may be any suitable size. Preferably, the through holes have a diameter of from 2.5 to 7.5mm, for example from 3 to 7mm, more preferably from 4 to 6mm, e.g. from 4.5 to 5.5mm, such as about 5mm.

The washer dryer machine may in one embodiment include valves to close the entry and exit chutes during the wash cycle. This can help to prevent heat loss from the water during the washing cycle and so improve the efficiency of the machine. In particular, there may be a valve in the entry chute and a valve in the exit chute which can be closed during the wash cycle and opened during the drying cycle. The opening and closing of the valves may suitably be controlled by the control system.

Preferably, the heating element for heating air to a required temperature is capable of heating air to a temperature of 4O⁰C or higher, e.g. 5O⁰C or higher, preferably 6O⁰C or higher, such as 7O⁰C or higher, e.g. 75⁰C or higher, preferably 8O⁰C or higher, such as 85⁰C or higher.

The detergent supply unit is suitably for feeding into the drum a powdered detergent, in a dosed amount.

In one embodiment, the machine further comprises an anti foam supply unit, for feeding into the drum anti foam, as required, in a dosed amount.

The air from the washing machine drum passes from the plurality of through-holes in the circumferential surface of the drum to the atmosphere via the exit chute. Preferably the passage of air from the plurality of through-holes in the circumferential surface of the drum to the atmosphere via the exit chute is through open passages. In particular it is preferred that the route taken by the air in this regard does not include any filters (e.g. lint filters) or the like which might become blocked over time. The machine is used for multiple wash and dry cycles, and the effective removal of moist air during all these cycles is important to ensure the effective and even drying needed to meet industry standards is achieved; therefore there should not be anything present in the exit route taken by the air that might block over the course of multiple cycles.

It is preferred that an open design is used for the exit route taken by the air, from the plurality of through-holes in the circumferential surface of the drum to the atmosphere via the exit chute, and that the flow speed of the air is selected to be sufficiently high, such that any lint or other debris is blown directly out to the atmosphere.

The air may be moved through the exit chute into the atmosphere at a speed of from 10 to 30m/s, e.g. from 12 to 25m/s, preferably from 13 to 20m/s, more preferably from 15 to 18m/s, such as from 16 to 17 m/s.

The control system suitably comprises a computing device, such as a microcomputer. The washing and drying machine may also comprise a signal input unit. The control system may control criteria relating to the operation of the washing and drying machine based on information received from the signal input unit. The signal input unit may, for example, receive information from sensors located in or associated with the machine. The sensors may be weight, temperature, moisture or other sensors. The sensors may provide information regarding factors such as the weight of the fabric load, the moisture levels in the air exiting the machine and the temperature of the heated air for drying.

Information may also be inputted manually into the control system, suitably via a control panel; for example information relating to the number of washing and drying cycles required, the type of fabric being washed, the type and/or amount of detergent to be used, the temperature at which the fabric should be washed, the time for which the fabric should be washed, the number of draining sequences to be used, the spin speed to be used, and/or the flow speed to be used for the heated air.

Preferably, the control system controls one or more of the following criteria:

(i) the temperature at which the fabric is washed by the washing machine;

(ii) the length of the washing cycle; (iii) the amount of water used; (iv) the amount of detergent used; (v) the spin speed during the washing cycle; (vi) the number of draining sequences carried out as part of the washing cycle; (vii) the temperature of the hot air used for the drying cycle;

(viii) the speed at which the hot air used for the drying cycle is fed into the drum;

(ix) the spin speed during the drying cycle; (x) the length of the drying cycle; (xi) the number of washing cycles;

(xii) the number of drying cycles.

Preferably, all of these criteria are controlled by the control system.

The control system may also control the amount of anti foam used, if any.

Preferably the control system receives information regarding the washing and drying process - e.g. the moisture levels in the air exiting the machine - and makes adjustments to the washing and/or drying cycles accordingly. In particular, the control system may adjust the length of the drying cycle and/or the temperature of the heated air for drying and/or the flow speed of the heated air for drying in response to information regarding the moisture levels in the air exiting the machine.

A printer panel may be provided, for example on the front of the machine. This can provide a paper print out of data relating to the wash and/or dry cycles once they are complete. This can be beneficial for providing information regarding the conditions used for testing, to ensure industry standards are met, and/or can help identify any possible problems with the smooth running of the machine and modifications that might be required. The invention also provides, in a second aspect, a method of ca rrying out multiple sequential washi ng and drying cycles of fabric, the method comprising the steps of:

I. providing a machine in accordance with the first aspect; II. carrying out a washing cycle using the washing machine; followed by

III. carrying out a drying cycle using the exhaust dryer; and then

IV. repeating steps II and III as required.

As the method involves multiple sequential washing and drying cycles, there is at least one repeat of steps II and III in step IV, such that there is a total of at least two wash and dry cycles.

In particular, the invention provides a method of ca rrying out multiple sequential washing and drying cycles of the same fabric load, the method comprising the steps of:

III. carrying out a drying cycle using the exhaust dryer; and then

IV. repeating steps II and III one or more times, as required.

The fabric load is suitably not removed from the machine until all required wash and dry steps are completed. For example, there may be ten or more wash and dry steps completed before the fabric load is removed, such as twenty or more, thirty or more, forty or more or fifty or more.

Preferably, as part of each washing cycle, one or more repeat of the drain sequence of the washing cycle is carried out, to remove further water from the fabric in the drum. For example, each washing cycle may include two drain sequences or three drain sequences. The use of such an additional drain sequence is advantageous in that it prevents fabric sticki ng to the drum wall prior to the drying cycle, which otherwise reduces the efficiency of the dryi ng cycle.

Preferably, in each drying cycle, atmospheric air is heated by the heating element, moved by the air mover through the entry chute into the washing machine drum and then exits the washing machine drum to the atmosphere through the exit chute via the plurality of through- holes in the circumferential surface of the drum.

Preferably, the atmospheric air is heated by the heating element to a temperature of 6O⁰C or higher, such as 7O⁰C or higher, e.g. 75⁰C or higher, preferably 8O⁰C or higher, such as 85⁰C or higher.

Preferably, in each drying cycle, the heated atmospheric air is moved by the air mover through the entry chute into the washing machine drum at a speed of from 10 to 30m/s, e.g. from 12 to 25m/s, preferably from 13 to 20m/s, more preferably from 15 to 18m/s, such as from 16 to 17 m/s.

The spin speed used in each drying cycle may be selected appropriately, depending upon factors such as the drum diameter. The skilled man will appreciate that the drum will momentarily stop during spin cycles, in particular when its direction of spin is reversed, i.e. at times its speed will be Orpm. However, when reference is made to spin speeds this refers to the average speed when the drum is actually moving during the spin cycle. In one embodiment, in each drying cycle, the drum is rotated at a spin speed of from 30 to 50rpm, such as from 31 to 48rpm, preferably from 32 to 46rpm, such as from 33 to 44 rpm, e.g. from 34 to 43 rpm, more preferably from 35 to 42rpm, most preferably from 36 to 41rpm.

In one embodiment, each drying cycle is stopped by the control system once measurements relating to the moisture levels in the air exiting the machine indicate that the fabric load has been dried to a desired moisture content, such as 3wt% moisture or less, e.g. lwt% moisture or less, preferably Owt% moisture.

In one embodiment, the method includes a total of 30 or more sequential washing a nd drying cycles of fabric, such as 35 or more, preferably 40 or more, such as 45 or more, more preferably 50 or more.

I n each washing cycle one or more detergent may be used to wash the fabric. Preferably, the detergent has flow properties such that 50Og of detergent per wash may be dispensed. The detergent may comprise non ionic surfactants and/or anionic surfacta nts.

I n one embodiment, it comprises from 5 to 1 5wt% non ionic surfactant and up to 5wt% anionic surfacta nt. It may also i nclude other components, such as si licate (e.g. metasilicate) ; sodium carbonate; sodium citrate; polymer (e.g. polymaleic acid) ; H EDP; and optical brightener.

The detergent may comprise anti foam (e.g. phosphoric acid ester). Alternatively or additionally, anti foam may be added separately to each wash cycle as required.

I n one embodiment, the detergent comprises:

Preferably 10kg of fabric or more is washed and dried, e.g. 1 5kg or more, such as 20kg or more, preferably 25kg or more, for exa mple from 25 to 30kg.

I n one embodi ment, the fabric that is washed and d ried has been treated with a flame retardant product. For exa mple, it may have been impreg nated with a flame retardant product or provided with a coating of flame reta rdant product.

The invention will now be further described, by means of example only, with reference to the drawings, in which : Figu re 1 is a drawing showing the front of a washing and drying machine in accordance with the present invention ;

Figure 2 is a drawing showing the rig ht hand side of the machine of Figure 1 ;

Figure 3 is a drawing showing the back of the machine of Figure 1 ; and

Figure 4 is a drawing showing the left ha nd side of the machine of Figure 1 .

Figures 1 to 4 show an industrial combined washing and drying machine 1 that is capable of ca rrying out multiple sequential washi ng and drying cycles of 25kg or more of fabric. The machine comprises an industrial sized front loading drum washing machine 2, and an exhaust dryer 3 located on top of the washing machine 2. It also has a control system (not shown) for controlling the washing of the fabric by the washing machine and the drying of the fabric by the exhaust dryer, such that multiple sequential cycles of washing and drying can be carried out under predetermined conditions.

The washing machine 2 has a drum (not shown) in which fabric can be washed, which is substantially cylinder-shaped and mounted so as to rotate around a substantially horizontal axis. There are a plurality of through- holes, for the passage of water to and from the drum, at the circumferential surface of the drum. The drum of the washing machine has a diameter of 980mm.

The washing machine 2 also has water supply holes 4, for feeding into the drum a controlled amount of water for washing or rinsing. The washing machine 2 has a detergent supply unit 5, for feeding into the drum a detergent, e.g. a powdered detergent, in a dosed amount.

The washing machine 2 has an anti foam supply unit 13, for feeding into the drum an anti foam agent, in a dosed amount, as required.

The washing machine 2 also has a heater (not shown), for heating the water to a predetermined temperature, and a motor (not shown), for rotating the drum.

The washing machine 2 also has a drainage unit 6, for removing water from the drum.

The washing machine 2 also has a circular inlet/outlet hole located in the front of the washing machine body, through which the fabric can be loaded into and unloaded from the drum, and an associated door 7 with handle 7a for opening and closing entry into the drum via said hole. The inlet/outlet hole is provided with an exterior wall 8 around its circumference, extending outwardly from the washing machine by about 15cm to define a circular outer hole at its distal end. The door 7 is located at the distal end of said exterior wall 8, and opens and closes the outer hole at this distal end of the exterior wall.

The exterior wall 8 has an interior surface that includes an angled portion that angles downwardly in the direction of the drum. This angled portion is present in the bottom quarter of the exterior wall. The a ngled portion is suitably at an angle of about 18° below the horizonta l.

The exhaust dryer 3 has a heating element (not shown) for heating air to a required temperature. The heating element is capable of heating air to a temperature of 4O⁰C or higher, such as 85⁰C or higher. The exhaust dryer 3 has an entry chute 9 for providing heated air into the washing machine drum. The entry chute 9 provides the heated air into the washing machine drum through the exterior wall 8. The heated air thus enters the drum via its front end. The chute has an end that feeds the air into the drum having an area of 0.314m². The chute feeds air into the drum at an angle of 16° to the vertical.

The exhaust dryer 3 also has a fan (not shown) for moving the air heated by the heating element through the entry chute into the washing machine drum. The fan moves the heated air through the entry chute 9 into the drum at a speed of 16 to 17m/s.

The exhaust dryer 3 also has an exit chute 10 for removing air from the washing machine drum to the atmosphere via the plurality of through- holes in the circumferential surface of the drum.

There is a sensor (not shown) in the exit chute 10 that measures the water level within the air passing through the exit chute 10. This may be used to ascertain the water levels in the fabric inside the drum. This sensor provides feedback to the control system, so that the control system can determine when the drying cycle can finish.

The control system controls the following criteria:

(i) the temperature at which the fabric is washed by the washing machine;

(ii) the length of the washing cycle;

(iii) the amount of water used;

(iv) the amount of detergent and, optionally, anti-foam, used;

(v) the spin speed during the washing cycle; (vi) the number of draining sequences carried out as part of the washing cycle;

(vii) the temperature of the hot air used for the drying cycle; (viii) the speed at which the hot air used for the drying cycle is fed into the drum;

(xii) the number of drying cycles.

A control panel 11 is provided on the front of the machine 1 , which allows the user to input the required washing and drying criteria into the control system. The control panel 11 may also indicate the status of the washing or drying cycle, e.g. in terms of the temperature, or the time left in the cycle.

A printer panel 12 is also provided on the front of the machine 1 , which provides a paper print out of data relating to the wash and dry cycle once it is complete.

In use, the machine 1 may be used to carry out multiple sequential washing and drying cycles of fabric, such as 50 sequential washing and drying cycles of fabric. Preferably 25kg of fabric or more is placed in the drum of the machine and is sequentially washed and dried. The fabric that is washed and dried may in particular be fabric that has been treated with a flame retardant product (e.g. it may have a coating of flame retardant product or may be impregnated with flame retardant product).

As part of each washing cycle, one or more repeat of the drain sequence of the washing cycle is carried out, to remove further water from the fabric in the drum.

As part of each drying cycle, atmospheric air is heated by the heating element, to 4O⁰C or higher, e.g. to 8O⁰C or higher, such as 85⁰C or higher.

Then it is moved by the fan through the entry chute 9 into the washing machine drum at a speed of 16 to 17m/s. The drum is rotated during the drying cycle at a spin speed of from 30 to 50rpm, e.g. from 36 to 41rpm. Air exits the washing machine drum to the atmosphere through the exit chute 10 via the plurality of through- holes in the circumferential surface of the drum. The amount of water in the exiting air is measured by the sensor in the exit chute 10. Once the water levels in the exit chute air are sufficiently low, indicating that the water levels in the fabric have reached the required standard of 0% + 3%, the heating element stops heating the air. Preferably, non warmed air is moved by the fan through the entry chute 9 into the washing machine drum for a period of time, to cool down the dried fabric before the drying cycle is completed.

Claims

1. An industrial combined washing and drying machine that is capable of ca rrying out multiple sequential washing and dryi ng cycles of the same fabric load, the machine comprising :

(a) an industrial sized front loading drum washing machine, having: i. a drum in which fabric can be washed, which is substantially cylinder-shaped and mounted so as to rotate around a substantially horizontal axis, wherein a plurality of through- holes, for the passage of water to and from the drum, are formed at the circumferential surface of the drum; ii. a water supply unit, for feeding into the drum a controlled amount of water for washing or rinsing; iii. a detergent supply unit, for feeding into the drum a detergent, in a dosed amount; iv. a heater, for heating the water to a predetermined temperature; v. a motor, for rotating the drum; vi. a drainage unit, for removing water from the drum; and vii. an inlet/outlet hole located in the front of the washing machine body, through which the fabric can be loaded into and unloaded from the drum, and an associated door for opening and closing entry into the drum via said hole;

(b) an exhaust dryer, having: i. a heating element for heating air to a required temperature; ii. an entry chute for providing heated air into the washing machine drum, wherein the entry chute provides the heated air via an end of the cylinder-shaped washing drum; iii. an air mover for moving the air heated by the heating element through the entry chute into the washing machine drum; and iv. an exit chute for removing air from the washing machine drum to the atmosphere via the plurality of through-holes in the circumferential surface of the drum; and (c) a control system for controlling the washing of the fabric by the washing machine and the drying of the fabric by the exhaust dryer, such that multiple sequential cycles of washing and drying can be carried out under predetermined conditions.

2. The machine of claim 1 wherein 20% by volume or less of the heated air is provided into washing machine drum via the through- holes in the circumferential surface of the drum.

3. The machine of claim 1 or claim 2 wherein no heated air is provided into washing machine drum via the through-holes in the circumferential surface of the drum.

4. The machine of any one of the preceding claims wherein 80% or more, by volume, of all the heated air provided into the washing machine drum is provided via an end of the cylinder-shaped washing drum.

5. The machine of claim 4 wherein 95% or more, by volume, of all the heated air provided into the washing machine drum is provided via an end of the cylinder-shaped washing drum.

6. The machine of any one of the preceding claims wherein the entry chute provides the heated air into the washing machine drum through the front of the washing machine.

7. The machine of any one of the preceding claims wherein the inlet/outlet hole is provided with an exterior wall around its circumference, extending outwardly from the washing machine to define an outer hole at its distal end, and the associated door is located at the distal end of said exterior wall, and opens and closes the outer hole at this distal end of the exterior wall.

8. The machine of claim 7, wherein the entry chute provides the heated air into the washing machine drum through the exterior wall.

9. The machine of claim 7 or claim 8, wherein the exterior wall has an interior surface that includes an angled portion that angles downwardly in the direction of the drum.

1 0. The mach i ne of cla i m 9, wherei n the a ng led portion is at a n a ng le of 1 0° or more below the horizonta l.

11. The machine of any one of the preceding claims, wherein the entry chute feeds air into the drum at an angle of 10° or more to the vertical.

12. The machine of any one of the preceding claims, wherein the air mover moves the heated air through the entry chute into the drum at a speed of from 15 to 18 m/s.

13. The machine of any one of the preceding claims, wherein the entry chute has an end that feeds the air into the drum having an area of 0.001m² or more.

14. The machine of claim 13, wherein the entry chute has an end that feeds the air into the drum having an area of from 0.02 to 0.04 m².

15. The machine of any one of the preceding claims, further comprising a sensor that directly or indirectly ascertains the water levels inside the drum.

16. A method of ca rrying out multiple sequential washing a nd drying cycles on the same fabric load, the method comprising the steps of: I. providing a machine in accordance with any one of the preceding claims;

II. carrying out a washing cycle using the washing machine; followed by III. carrying out a drying cycle using the exhaust dryer; and then IV. repeating steps II and III one or more times, as required.

17. The method of claim 16, wherein as part of each washing cycle, one or more repeat of the drain sequence of the washing cycle is carried out, to remove further water from the fabric in the drum.

18. The method of claim 16 or claim 17, wherein in each drying cycle, atmospheric air is heated by the heating element, moved by the air mover through the entry chute into the washing machine drum and then exits the washing machine drum to the atmosphere through the exit chute via the plurality of through-holes in the circumferential surface of the drum.

19. The method of any one of claims 16 to 18, wherein in each drying cycle the atmospheric air is heated by the heating element to a temperature of 6O⁰C or higher.

20. The method of any one of claims 16 to 19, wherein in each drying cycle, the heated atmospheric air is moved by the air mover through the entry chute into the washing machine drum at a speed of from 15 to 18m/s.

21. The method of any one of claims 16 to 20, wherein in each drying cycle, the drum is rotated at a spin speed of from 36 to 41 rpm.

22. The method of any one of claims 16 to 21 , wherein the method includes a total of 30 or more sequential washing a nd drying cycles of the same fabric load.

23. The method of any one of claims 1 6 to 22, wherei n 25kg or more of fabric is washed and dried.

24. The method of any one of claims 1 6 to 23, wherein the fabric that is washed and dried has been treated with a flame retarda nt product.