CN110662863A

CN110662863A - Device for removing fluid and washing apparatus comprising said device

Info

Publication number: CN110662863A
Application number: CN201780091211.2A
Authority: CN
Inventors: 布鲁诺·斯科尔特加格纳
Original assignee: Lafer SpA
Current assignee: Lafer SpA
Priority date: 2017-05-31
Filing date: 2017-05-31
Publication date: 2020-01-07
Also published as: EP3631072A1; WO2018219441A1; EP3631072B1; TW201903241A

Abstract

The invention relates to a device for removing fluid from fabrics (12), which can be used under pressure in a treatment chamber (14) in which the fabrics (12) are washed in a bath of liquid carbon dioxide (23) to remove residual carbon dioxide from the fibres. The invention also relates to a washing apparatus comprising said removal device.

Description

Device for removing fluid and washing apparatus comprising said device

Technical Field

The present invention relates to a device for removing fluids and to an apparatus for washing fabrics, which apparatus, including the device, can be used in the industrial field of textile products. In particular, the textile may consist of textile fibres of animal, vegetable, artificial, synthetic or hybrid type.

More particularly, the present invention relates to a scrubbing apparatus using carbon dioxide as a main scrubbing liquid and a device for removing carbon dioxide.

Background

In the industrial field of textile production, it is known to carry out at least one washing treatment, for example at the completion of a work or during one or more intermediate steps, in order to remove contaminants present therein, such as grease. A working residue.

In the textile industry, one of the steps prior to dyeing and finishing of fabrics is the washing/rinsing of fabrics, defined in the art by the english word "scuring". This step of the process is essential for removing the oils and/or paraffins or other textile auxiliaries used in the spinning and/or weaving process.

If these substances are not properly removed, stains and uneven parts are formed during dyeing, and thus further dyeing is required, and accordingly, a very large amount of water is used. Furthermore, the residual textile auxiliary tends to cause problems of emission to the atmosphere during the heat-setting process immediately thereafter.

Generally used washing methods generally use solvents, hydrocarbons and/or aqueous solutions containing specific saponified substances, detergents, wetting agents, surfactants, etc., depending on the type of contaminants to be eliminated.

Heretofore, washing processes using water and detergents to facilitate removal of contaminants have been widely used, although they have a very adverse effect on the environment. However, safety and environmental regulations are becoming more stringent, and it is therefore necessary to identify industrial washing processes that have minimal or no environmental impact.

It is therefore of great importance to use, on the one hand, substances which do not cause environmental pollution and, on the other hand, methods which ensure the removal of the grease from the fabric.

At the present time, on an industrial level, a macroscopic distinction is identified between plants in which the fabric is treated discontinuously and plants in which the fabric is treated continuously.

Apparatuses for discontinuous treatment of fabrics are comparable to large industrial washing machines which use different systems for batch treatment of fabrics (or garments), such as:

hydrocarbons (different types of hydrocarbons are on the market);

-tetrachloroethylene or perchloroethylene;

-water in combination with detergents, dispersants and various reagents;

-carbon dioxide CO₂。

Such plants are usually equipped with recovery and recycling systems for the products used. The productivity of these plants is limited by the load capacity.

In plants for continuous treatment of fabrics, the fabric is collected on reels or trolleys, then unwound and inserted into treatment units and subjected to continuous treatment. At the end of the treatment, the fabric is rewound into rolls or layered deposition.

Continuous-working plants are basically divided into water-washing systems and dry-cleaning systems.

The former uses large amounts of water and soap, as well as dispersants and wetting agents and surfactants to increase the effectiveness of the process. The processed fabric must then be dried, which means that a large amount of energy is used and thus the processing costs are increased. Furthermore, the water used requires expensive purification equipment.

In contrast, dry cleaning plants use tetrachloroethylene (perchloroethylene), which can treat the fabric from drying to drying: this chlorinated solvent, although it does have excellent solvent properties (kauri-butanol (Kb) index of 90) and various fabrics are compatible, has a negative impact on the toxicity of the aquatic environment and its suspected carcinogenicity. For these reasons, strict regulatory restrictions have been set on the use of the substance in order to eliminate its use step by step.

Modern machines using tetrachloroethylene must enforce a series of measures aimed at ensuring almost complete distillation and recovery of the solvent used. However, a portion of the solvent remains in the sludge to be treated, i.e. in the oil extracted from the fabric, causing it to be classified as "hazardous waste".

Currently, no continuously operating plant providesWith hydrocarbons or CO₂To treat the fabric. This limitation is intrinsically related to the physicochemical properties of the substance.

In the case of hydrocarbons, it is necessary to use an expensive vacuum distillation system because of the low flammability value of the hydrocarbons. In addition, since the dissolving power of these substances is low (kauri-butanol index value is about half of perchloroethylene, or less than perchloroethylene), the treatment time will be greatly prolonged, thereby limiting productivity.

In the case of carbon dioxide, the operating conditions of the liquid state make it necessary to operate at very high pressure values: in discontinuous machines, pressures of about 50bar or higher are mentioned. These conditions exclude the possibility of building a continuous plant at competitive costs on the market.

CO₂Has a variety of properties that make it particularly suitable for scouring/washing fabrics.

Liquid carbon dioxide has a considerable capacity for dissolution, especially for non-polar substances; these functions may achieve or even improve the cleaning effect obtained so far by other known methods.

Carbon dioxide is a substance that is readily available on the market at low cost, since it is a residue of other production processes, from which it can be suitably utilized for reuse.

When in liquid state, CO₂Has very low surface tension and viscosity values, which leads to CO₂It is a very good wetting agent and can even remove very viscous liquids from the depth of the fabric, such as complex-composition mineral oils, hydrocarbon fluid oils or paraffins.

It should be noted that carbon dioxide is an excellent solvent in every of its physical states.

In view of the increasing regulatory efforts aimed at eliminating harmful substances and gradually reducing water consumption, carbon dioxide has proved to be the most suitable solution for incorporating and removing non-polar auxiliary textiles from fabrics.

CO used in the prior art₂The washing method is generally intended to be installed in a laundryAnd primarily treating the garments by immersing the garments in a liquid carbon dioxide bath within a pressurized treatment chamber. Known washing processes are typically operated at pressures of about 50bar or more. Generally, as in a conventional washing machine, laundry is inserted into an apparatus provided with a rack rotating within a drum.

On this problem, the following documents are known:

US-A-4012194 describes A process for preparing A polymer having A corresponding CO₂A method of extracting and washing garments using liquid carbon dioxide in a closed chamber of a recirculation/recovery system and filtration/drainage of oil.

US-A-5858022 describes the passing of CO₂Water, a surfactant and an organic co-solvent into a rotating drum.

US-A-5904737 describes A method for washing laundry which uses different pressure conditions to recirculate solvent in A system comprising A main chamber for washing the laundry and A series of tanks connected to A compressor. Carbon dioxide is injected into the chamber by means of a nozzle which contributes to the mechanical action on the product to be dry-cleaned.

US-A-5412958 describes washing of finished garments in A chamber equipped with A rotating drum for separating and collecting "dirt". Filtering and recovering the carbon dioxide used in the process.

One disadvantage of these methods is that if industrial fabrics are inserted into the apparatus, they are less likely to be cleaned evenly. Indeed, throughout the wash cycle, the fabric is not uniformly positioned in the bath, so certain areas can be treated and cleaned better than others, resulting in uneven washing or stains on the fabric.

Another disadvantage is that there are significant limitations on the productivity of the process due to the discrete operating conditions (batches).

The upstream process also has CO prior to weaving₂Washing applications, i.e. directly on the fibres.

US-B-6183521 specifies the use of supercritical CO at a pressure of between 90 and 350bar and a temperature of between 40 ℃ and 120 ℃₂. The method can improve the strength and elongation of the fiber compared to the conventional method for refining.

CO for use in fabric washing machines is also known₂Different systems of recovery and distillation.

In this respect, EP-A-2098307 describes ｃA CO for use in garments₂The distillation system of a dry cleaning machine, that is, it relates to a small machine. The plant distills the carbon dioxide used in the process in two steps: the first step is carried out in a first distillation unit, in a second distillation unit, the majority of the carbon dioxide is separated from the extracted substances; the second step is carried out in a second distillation unit in order to increase the overall efficiency of the separation.

However, in the case of continuous processing, JP-A-2010180385(JP'385) describes continuous high-pressure processing of ｃA plain film. The process provides an unwinding and winding device of the treated product within a chamber divided into two or more compartments having different operating conditions.

One disadvantage of prior art systems is that they allow only partial recovery of the carbon dioxide used in the washing process, since much of the liquid carbon dioxide is still entrained in the fibers of the fabric.

The solutions described in the documents cited above, such as JP'385, necessarily have the problem of removing carbon dioxide from the washed fabrics or clothes due to their way of working, but this problem is not described or solved. In any manner.

Therefore, the solutions proposed in the various documents are limited in their use and are not easy to implement in practice.

In the case of a single garment, it may be simple to remove the carbon dioxide from the garment, since it is sufficient to hang it out for drying at the end of the treatment or to dry it using known systems.

However, in the case of industrial-scale fabric rolls, the problem of carbon dioxide removal is very complex. In fact, after the fabric is impregnated and wound, it is very difficult to remove carbon dioxide therefrom, since it cannot be delaminated and evaporated outwardly.

For example, at the end of the washing operation, the fabric is at a temperature of between 1 ℃ and 6 ℃ considering that it is carried out at a value of between 35 and 40 bar. When the treatment chamber is depressurized to allow removal of the fabric, the temperature of the carbon dioxide is thus reduced. The very high heat content of the fabric, combined with the heat input generated by the cooling of the liquid carbon dioxide, causes a portion of the carbon dioxide trapped in the fabric to evaporate, typically accounting for 45% of the total absorbed carbon dioxide.

However, there is still a significant portion of carbon dioxide inside the fabric, which tends to solidify as the pressure in the treatment chamber drops (in the CO2 state diagram, the triple point is 5.11atm and-56.6℃).

The frozen and frozen carbon dioxide entrapped in the fabric also adds significantly to its weight. For example, considering a fabric roll weighing about 400kg, the carbon dioxide remaining therein may correspond to about 220kg (which represents 55% of the impregnated carbon dioxide).

In this case, further processing is required to remove the frozen carbon dioxide from the fabric, thereby increasing production time, and strategies are required to prevent carbon dioxide from diffusing into the environment.

The applicant has become aware of the problem and has sought a solution by conducting tests and experiments.

Starting from the prior art described above, in the case of washing of fabrics, in particular in rolls, with liquid carbon dioxide in a treatment chamber, it is an object of the present invention to achieve an apparatus and a related washing method such that carbon dioxide can be almost completely removed from the fabrics before the washing process is finished and then removed from the treatment chamber.

Another purpose of the present invention is to obtain a washing apparatus and a method of connection that will allow to obtain, at the end of the washing treatment and upon leaving the treatment chamber, a roll of fabric having a weight substantially equal to this weight. The fabric rolls are passed through before the laundering process, except for the materials and grease removed during the laundering process.

Another object of the present invention is to obtain a washing plant and a connected method that allow substantially all the carbon dioxide used in the washing process to be recovered and recycled in a closed circuit, without its dispersion into the environment.

Another object is to obtain residual sludge containing oils, fats, etc. which is free of contaminants such as solvents, etc., so that it can be disposed of as harmless waste.

Another object is to provide a washing method which has a small impact on the environment and is not polluting, but which at the same time is effective and allows to obtain good cleaning of the fabrics.

The applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

Disclosure of Invention

The invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, the present invention relates to a device for removing carbon dioxide from fabrics, which can be used in a pressurized treatment chamber, which is suitable for washing said fabrics to remove non-polar substances therefrom.

The removing device includes: a mechanical removal member adapted to exert a mechanical action on the fabric to remove a portion of the carbon dioxide entrained in the fibers; and a heat removal member configured to heat the fabric and evaporate a portion of the carbon dioxide remaining in the fibers.

According to some embodiments, the heat removal means is arranged directly downstream of the mechanical removal means.

The combined and sequential action of mechanical removal of carbon dioxide and thermal removal of carbon dioxide allows for the removal of substantially all of the liquid carbon dioxide absorbed by the fabric, thereby obtaining a substantially dry fabric.

The invention also relates to an apparatus for washing fabrics, comprising at least one treatment chamber for carrying out a washing treatment of the fabrics with carbon dioxide, and a circuit for recycling and recovering the carbon dioxide associated with the treatment chamber.

According to some embodiments, the recirculation and recovery circuit is provided with a pressure regulating device configured to set and regulate a desired pressure inside the process chamber.

The treatment chamber comprises at least two winding/unwinding rollers configured to wind and unwind, respectively, the wound fabric so as to be in mutual communication, a possible return roller defining the travel of the fabric to be treated, and a containing tank suitable for containing a bath of liquid carbon dioxide, in which the fabric can be conveyed during its travel from one winding/unwinding roller to the other.

According to one aspect of the invention, the apparatus comprises at least one removal device according to the invention configured to substantially completely remove liquid carbon dioxide from the fabric at the end of the washing treatment.

The removal device is arranged inside the treatment chamber, in an intermediate position between the containing tank and the winding/unwinding roller, in which the fabric is wound at the end of the treatment.

On the one hand, this ensures that the carbon dioxide used in the scrubbing process is completely recovered, so that it can be reused in a closed circuit without being dispersed into the environment.

This is particularly advantageous in the case of a scrubbing apparatus comprising two or more process chambers sharing a single carbon dioxide recycle and recovery loop.

The carbon dioxide is completely removed from the fabric prior to being evacuated from the treatment chamber, so that it can be completely reused in another treatment chamber without the need to provide more carbon dioxide for each wash cycle to compensate for the carbon dioxide remaining in the fabric which is only being washed.

The invention also relates to a method for washing fabrics, which provides to insert a roll of fabric to be washed into a treatment chamber, sucking it on at least two winding/unwinding rollers and possibly on a return roller defining a stroke for the fabric to be treated; to generate the required pressure inside the treatment chamber and to carry out the transfer in a bath of liquid carbon dioxide during its travel from the winding/unwinding roller to the other winding roller, to carry out at least one cycle of the fabric washing treatment; to restore the atmospheric pressure in the treatment chamber and finally to withdraw the roll from the treatment chamber.

According to one aspect of the invention, the washing process provides for substantially complete removal of carbon dioxide entrained in the fabric fibers in the liquid carbon dioxide bath prior to withdrawal of the fabric roll from the treatment chamber.

According to some embodiments, the washing process provides for removing carbon dioxide from the fibers of the fabric prior to winding the fabric on a winding/unwinding roll.

According to a further embodiment, the method provides for performing the mechanical removal action by pressing/compressing the fabric to remove the first portion of liquid carbon dioxide therefrom, and performing the thermal removal action by heating the fabric to evaporate it and remove residual carbon dioxide.

According to a further embodiment, the mechanical removal action and the thermal removal action are carried out one after the other in time, in order to optimize the overall efficiency of the removal and to obtain a substantially dry fabric before winding it on the winding/unwinding roller.

Since the fabric has been dried before winding, the weight of the roll to be removed from the treatment chamber at the end of the washing process will be substantially equal to the weight at the entry, with the exception of the removed substances and grease.

Furthermore, the fabric roll exiting the treatment chamber can be used directly, or subjected to further work processes, without the need to provide intermediate treatment steps to remove residual carbon dioxide, thereby reducing overall production time and cost.

Drawings

These and other features of the invention will become apparent from the following description of some embodiments, given as non-limiting examples with reference to the accompanying drawings, in which:

fig. 1 is a schematic view of a washing apparatus according to embodiments described herein.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is to be understood that elements and features of one embodiment may be readily combined with other embodiments without further recitation.

Detailed Description

Reference will now be made in detail to an embodiment of the present invention, an example of which is illustrated in the accompanying drawings.

The embodiment described herein with reference to fig. 1. Detailed description of embodiments the washing machine 10 in fig. 1 refers to a washing machine 10 that can be used in the field of textile production, for example for removing oils and/or paraffins or other textile auxiliaries used in spinning and/or weaving steps.

The washing apparatus 10 according to the invention comprises at least one treatment chamber 14, in which chamber 14 a roll of fabric 12 to be washed can be introduced.

The term fabric 12, as used herein and in the following description, refers to a fabric generally composed of textile fibers of animal, vegetable, man-made, synthetic or hybrid types.

The fabric 12 may also be an open fabric, a tubular fabric or a fabric folded lengthwise over itself and sewn.

The cleaning apparatus 10 also comprises a recovery and recirculation loop 16 of the cleaning liquid, in this case carbon dioxide (CO)₂). According to some embodiments, the process chamber 14 is provided with liquid CO disposed on the sidewalls of the process chamber 14₂An inlet 17 and liquid CO arranged in correspondence of the bottom wall₂An outlet 18.

According to some embodiments, the liquid CO₂The outlet 18 cooperates with a containing tank 22 arranged inside the treatment chamber 14, which tank 22 is suitable for containing a bath 23 of liquid carbon dioxide, in which the fabric 12 to be washed can pass.

The process chamber 14 also includes gas holes 19 through which gaseous carbon dioxide can pass through the gas holes 19.

According to some embodiments, the recovery and recirculation loop 16 may include

pressure regulating devices

30, 32, the

pressure regulating devices

30, 32 corresponding to the process chamber 14, corresponding to the gas vent 19, and configured to set and regulate a desired pressure therein.

The recovery and recycle loop 16 may also include at least one liquid carbon dioxide collection tank 36, which is connected to both the liquid CO₂Inlet 17, in turn connected to liquid CO₂An outlet 18.

According to further embodiments, the recovery and recycle loop 16 may comprise a condenser arrangement 34, which condenser arrangement 34 is connected to the

pressure regulating arrangement

30, 32 and the collecting tank 36, and is configured to condense gaseous carbon dioxide to obtain liquid carbon dioxide.

According to some embodiments, the treatment chamber 14 comprises at least one pair of winding/

unwinding rollers

20a, 20b, each configured to wind a roll of fabric 12 from one to the other.

In particular, the fabric 12 to be washed is wound onto a first unwinding roller 20a and drawn onto a second winding roller 20 b. According to a possible solution, the treatment chamber 14 may comprise one or more return rollers 21, the return rollers 21 being configured to define a stroke P of the fabric 12 inside the treatment chamber 14 and to keep the fabric 12 stretched between one and the other winding/unwinding

roller

20a, 20 b.

Although fig. 1 shows a feel of the travel P from the unwinding roller 20a to the winding roller 20b, it can be provided that the winding/

unwinding rollers

20a, 20b can be interchanged so that both can perform the fabric winding or unwinding function. Therefore, as shown in fig. 12, the stroke P of the web 12 can be reversed, unwound from the unwinding roller 20b, and wound around the winding roller 20 a.

According to some embodiments, a delivery nozzle 24 may be provided inside the treatment chamber 14, configured to deliver carbon dioxide in liquid form onto the fabric 12 during winding/unwinding thereof.

According to some embodiments, the delivery nozzle 24 is passed through the liquid CO from the recovery and recirculation loop 16₂And is supplied through an inlet 17.

According to other embodiments, the treatment chamber 14 may comprise, inside it, a beating roller 25, which beating roller 25 is configured to beat the fabric 12 in the travel section between one and the other of the winding/

unwinding rollers

20a, 20b, so as to generate a mechanical beating action, thus increasing the movement of the fabric 12 itself, further promoting the removal of the contaminants.

According to an aspect of the invention, the apparatus 10 comprises at least one removal device 29, the at least one removal device 29 being configured to substantially completely remove liquid carbon dioxide from the fabric 12 at the end of the washing treatment.

The removal device 29 is arranged in the treatment chamber 14 in an intermediate position between the containing tank 22 and the winding

rollers

20a, 20b, on which the fabric 12 is wound at the end of the treatment.

According to a further embodiment, the apparatus 10 may comprise two removing devices 29, each removing device 29 being arranged between one of the winding/

unwinding rollers

20a, 20b and the containing groove 22.

In this way, the fabric 12 can be suitably dried both in the washing courses having an odd number of washing cycles, which means winding/unwinding of the fabric 12 from one to the other of the winding/

unwinding rollers

20a, 20b, and in the washing courses having an even number of washing cycles.

According to some embodiments, the removal means 29 comprise mechanical removal means 27, the mechanical removal means 27 being adapted to exert a mechanical action on the fabric 12 in the downstream transit of the carbon dioxide bath 23 to remove at least a portion of the carbon dioxide trapped in its fibers.

The removal device 29 also comprises a heat removal member 28 configured to heat the fabric 12 and evaporate the remaining part of the carbon dioxide remaining in its fibers before winding it onto one of the winding/

unwinding rollers

20a, 20b at the end. The washing process is conducted so that the carbon dioxide remaining in the fabric 12 is in a gaseous state.

In this way, carbon dioxide may be completely removed from the fabric 12 by the recovery and recirculation loop 16 and carbon dioxide may be more efficiently recovered from the treatment chamber 14.

According to some embodiments, the heat removal member 28 is arranged directly downstream of the mechanical removal member 27.

According to some embodiments, the mechanical removal member 27 may comprise at least one press roll 26, which press roll 26 cooperates with an idle or stretched draw or return roll 21a to press the fabric 12 under conveyance, thereby removing from the fabric most of the liquid carbon dioxide remaining in its fibers.

According to some embodiments, the heat removing member 28 may be, for example, a heated roller having a single chamber or a double chamber, over which the fabric 12 may be conveyed.

According to further embodiments, the heat removing member 28 may include one or more heating plates.

According to possible embodiments, the heat removing means 28 may comprise or be connected to a heat generating device, such as a steam generator, an electrical resistance, a diathermic oil, hot water, infrared, ultrasound or others.

According to some embodiments, more press rolls 26a may be provided, which are arranged in correspondence with the containing tank 22 to immerse the fabric 12 therein again before pressing/compressing it from the outlet of the liquid carbon dioxide bath 23.

According to some embodiments, the carbon dioxide recovery and recycle loop 16 may comprise a plurality of pipes and communication and transport lines for carbon dioxide, and be provided with one or more regulating/shutoff valves.

The valves can be opened or closed to allow or prevent the passage of carbon dioxide in the respective pipes or the respective communication lines and possibly to regulate the flow.

According to other embodiments not shown, the scrubbing apparatus 10 may include two or more process chambers 14, which may share a single carbon dioxide recovery and recycle loop 16.

In particular, by opening/closing the valves, each treatment chamber 14 can be connected in each case selectively with a

pressure regulating device

30, 32, a collecting tank 36 and/or another treatment chamber.

According to some embodiments, the recovery and recirculation loop 16 further comprises at least one suction device 30, the suction device 30 being configured to suction the gas present in the process chamber 14 so as to define a desired pressure inside it.

According to some embodiments, the recovery and recirculation loop 16 further comprises a compression device 32, which may be connected to the process chamber 14 through an air vent 19.

According to a possible variant embodiment, the compression device 32 is a dry compressor, which acts on the carbon dioxide in gaseous form.

According to some embodiments, a compression device 32 is also connected to the suction device 30.

According to some embodiments, the compression device 32 is arranged downstream of the suction device 30 so as to receive at the inlet the gaseous carbon dioxide sucked by the suction device from the treatment chamber 14.

According to some embodiments, the recovery and recirculation loop 16 further comprises a condenser arrangement 34, which condenser arrangement 34 may be connected to the compression arrangement 32.

According to a further embodiment, the condenser device 34 may also be connected to a collection tank 36 for liquid carbon dioxide.

According to further embodiments, the process chamber 14 is also passed liquid CO₂The outlet 18 is connected to the collection tank 36 in correspondence of the accumulation area of the liquid carbon dioxide.

In particular, the apparatus 10 allows for the passage of liquid CO₂The outlet 18 recovers carbon dioxide in liquid form and carbon dioxide in gaseous form through the vent 19.

It should be noted that if the washing apparatus 10 according to the present invention comprises more than one treatment chamber, it allows to carry out a "semi-continuous" treatment of the fabric 12, or a washing treatment of the first roll of fabric. In a second treatment chamber (not shown), the second fabric chamber 12 in the first treatment chamber 12 may be removed, while the second treatment chamber (not shown) is removed from the previous wash cycle and loaded with a second roll of fabric 12 to be treated.

The embodiments described herein also relate to a process for washing fabrics 12 in a treatment chamber 14.

According to some embodiments, the washing process comprises: inserting a roll of fabric 12 into a treatment chamber 14, said fabric 12 being drawn over a plurality of rollers 20, 21; impregnating the fabric 12 by spraying liquid carbon dioxide thereto; it is immersed in a liquid carbon dioxide bath 23 and wound on a winding roll 20.

After the fabric 12 is inserted and pulled in, the treatment chamber 14 is closed and pressurized.

According to some embodiments, the pressure inside the treatment chamber 14 may be comprised between about 10 bar and about 60bar when performing a washing treatment on the fabric 12.

Once the washing process is complete, the treatment chamber 14 is depressurized to allow the washed fabric 12 roll to be withdrawn.

According to a further embodiment, the treatment chamber 14 may be subjected to a high vacuum cycle before loading a new fabric roll 12, to eliminate possible residues of the previous washing cycle.

For example, according to some embodiments, it may be provided to bring the process chamber 14 to a pressure of about 0.001 bar.

According to some embodiments, thanks to the removal means 29 and to the recovery and recirculation circuit 16, the apparatus 10 is able to recover substantially all the carbon dioxide used for each washing treatment of the fabrics 12 in the treatment chamber 14, only the oils obtained and the substances extracted as waste will be eliminated.

According to some embodiments, the washing treatment provides to carry out at least one fabric washing cycle defined by the complete winding/unwinding of the fabric 12 from one winding/unwinding roller 20 to another.

According to some embodiments, the number of washing cycles, i.e. the number of windings/unwinds of the fabric 12 on the respective winding/unwinding roller 20, can be selected according to the type of fabric 12 and/or the type of contaminants that need to be removed.

According to some embodiments, the washing process may provide for passing the fabric 12 through the liquid carbon dioxide bath 23 one, two, or more times in succession to facilitate removal of fatty substances present on the fabric 12 and associated with the liquid carbon dioxide molecules.

According to various embodiments, one or more appropriately positioned return rolls 21 may be used to pass the fabric 12 inside and outside the liquid carbon dioxide bath 23.

According to some embodiments, the washing process may be performed at a washing temperature between about-40 ℃ to about 25 ℃.

Carbon dioxide has excellent antibacterial properties, and thus can secure deep cleaning and sterilization even at low temperatures.

According to some embodiments of the present invention, the washing process provides for substantially complete removal of carbon dioxide entrained in the fibers of the fabric 12 in the liquid carbon dioxide bath 23 prior to withdrawing the roll of fabric 12 from the treatment chamber 14.

According to some embodiments, the washing process provides for the removal of carbon dioxide from the fibers of the fabric 12 prior to winding the fabric 12 onto the winding/unwinding

roll

20a or 20 b.

According to further embodiments, the method provides the acts of performing mechanical removal by pressing/compressing the fabric 12 to remove a first portion of the liquid carbon dioxide therefrom, and performing thermal removal by heating the fabric 12 to cause the remaining carbon dioxide to evaporate and be removed.

According to a further embodiment, the mechanical removal action and the thermal removal action are carried out one after the other in time, so as to optimize the overall efficiency of the removal action and obtain a substantially dry fabric 12 before winding it on the winding/unwinding roller 20.

Furthermore, the roll of fabric 12 at the outlet of the treatment chamber 14 can be used directly or subjected to further treatment processes without the need to provide intermediate treatment steps for removing carbon dioxide, thereby reducing overall production time and costs.

According to some embodiments, if the laundering apparatus 10 comprises two or more treatment chambers 14, the fabric laundering process also provides for continuously recycling and regenerating the carbon dioxide used in the first treatment chamber 14 through the recovery and recycle loop 16 during the laundering cycle, and then reusing it in the closed loop of the second treatment chamber 14.

According to some embodiments, the liquid carbon dioxide may be continuously subcooled and/or maintained at a particular temperature at which the process is to be conducted, for example, by subcooler devices and/or heaters, not shown.

For example, the subcooler means may cool the carbon dioxide to a temperature of about-40 ℃ to maintain it in a subcooled liquid state.

According to some embodiments, the liquid carbon dioxide used in the process chamber 14 may be continuously filtered during the process cycle to eliminate impurities and contaminants collected therein.

According to some embodiments, at the end of each washing cycle, liquid carbon dioxide may be extracted from the treatment chamber 14 to clean the apolar substances removed during the washing cycle, such as oils, fatty substances, paraffins.

According to other embodiments, other membrane technologies, such as microfiltration, nanofiltration or reverse osmosis, may be utilized in conjunction with or as an alternative to ultrafiltration to clean and regenerate liquid carbon dioxide.

According to a variant embodiment, the liquid carbon dioxide containing contaminants can be distilled without using ultrafiltration.

It is clear that modifications and/or additions may be made to the washing plant and to the method for fabrics as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of removal device, and apparatus and method for washing fabrics, the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claims

1. Device for removing liquid carbon dioxide under pressure from a fabric (12) usable in a treatment chamber (14), suitable for washing said fabric (12) in a bath of liquid carbon dioxide (23) in order to remove apolar substances therefrom, characterized in that said removal device (29) comprises a mechanical removal member (27), which mechanical removal member (27) is suitable for exerting a mechanical action on the fabric (12) to remove a portion of said carbon dioxide entrained in the fibers, and a thermal removal member (28) configured to heat the fabric (12) and to evaporate a residual portion of said carbon dioxide remaining in the fibers.

2. A removal device according to claim 1, characterized in that the heat removal means (28) are arranged directly downstream of the mechanical removal means (27).

3. The removal device according to claim 1 or 2, characterized in that the mechanical removal member (27) comprises at least a press roll (26) and a traction or return roll (21a), the press roll (26) being configured to press/compress the fabric (12) along the traction or return roll (21 a).

4. A removing device according to any of claims 1-3, characterized in that the heat removing member (28) comprises at least one heated roll with single or double chambers around which the fabric (12) can be conveyed.

5. A removing device according to any of claims 1-3, characterized in that the heat removing member (28) comprises one or more heating plates.

6. -removal device according to any one of the preceding claims, characterised in that the heat removal member (28) comprises or is connected to a heat-generating device, such as a steam generator, an electrical resistance, a diathermic oil, hot water, infrared, ultrasound or other.

7. An apparatus for washing fabrics (12), comprising at least one treatment chamber (14) to carry out a washing treatment on fabrics (12) with carbon dioxide, and a recovery and recirculation circuit (16) of carbon dioxide associated with said treatment chamber (14), characterized in that said treatment chamber (14) comprises at least two winding/unwinding rollers (20a, 20b) respectively configured to wind and unwind the wound fabrics (12) onto and from each other, and a containing tank (22) suitable for containing liquid carbon dioxide (23) bath, in which said fabrics (12) can be conveyed during the travel from one winding/unwinding roller (20) to the other, said apparatus further comprising at least one removal device (29) according to any one of claims 1 to 6, said removal device (29) being provided inside said treatment chamber (14), is located in an intermediate position between the housing tank (22) and the rollers (20a, 20b), the fabric (12) being wound up on the rollers (20a, 20b) in said intermediate position at the end of the treatment.

8. Washing apparatus according to claim 7, characterized in that it comprises two removal devices (29), each removal device (29) being arranged between one of the winding/unwinding rollers (20a, 20b) and the containing tank (22).