WO2025202833A1

WO2025202833A1 - Apparatus and procedure for water separation and related system for washing a fabric web

Info

Publication number: WO2025202833A1
Application number: PCT/IB2025/053005
Authority: WO
Inventors: Alessandro ZUCCHI
Original assignee: Ferraro SpA
Current assignee: Ferraro SpA
Priority date: 2024-03-27
Filing date: 2025-03-21
Publication date: 2025-10-02
Anticipated expiration: 2026-09-27

Abstract

The present disclosure relates to an apparatus for separating water from an oil-water mixture, or from a. mixture of solid particulate matter in water, or from a mixture of solid particulate matter with oil and water. The apparatus uses a motorized hollow roller which defines a lateral surface with through holes and which is covered externally by a filter permeable to water. According to the separation process of this disclosure, the motorized roller is rotated so that a portion of the filter separates the water from the mixture retaining oily and/or solid residues, and can be taken outside the mixture so that the filter can be cleaned by aspirating the oily and/or solid residues that impregnate it.

Description

APPARATUS AND PROCEDURE FOR WATER SEPARATION AND RELATED SYSTEM FOR WASHING A FABRIC WEB

TECHNICAL FIELD

This disclosure concerns techniques for recovering water from a washing or purging liquid. More specifically, this disclosure concerns an apparatus and process for separating water and a related washing system for a fabric web.

BACKGROUND

In industrial weaving processes, washing is necessary to eliminate impurities from raw or semi-finished fabrics, such as weaving residues, as well as chemical products such as caustic soda and bleaching products. In the case of the removal of weaving oils, washing is more intense and requires specific solvents, which is why it is generally called “purging”.

Well-known fabric washing systems include one or more washing units inside which are housed tanks intended to contain washing and rinsing liquids. Inside the washing units, rollers or cylinders are mounted in a rotating manner that define a washing path for a fabric strip from an inlet to an outlet of the washing unit itself.

At the bottom of the washing tanks it is typically collected a mixture of water with weaving oil and, in addition or alternatively, with solid residues from fabric processing that appear in the form of solid particles dispersed in water. This mixture could simply be disposed of, but this would have a significant environmental impact and would also involve costs for discharge as well as for the supply of clean water. Since the mixture is mostly made up of water, it would be very convenient to treat this mixture to separate the water from the weaving oil and/or the solid particles dispersed in it, so as to reuse the same water several times for the “purging” operations of fabrics before having to discharge it. Furthermore, separating the water from the weaving oil and/or the solid particles is important to comply with legal constraints against pollution.

The problem of separating water that can be reused from a mixture of water and oil and/or solid particulate arises not only in the filtering of textile washing water, but also in other fields of technology where w aste water mixtures containing oily residues and/or solid particulates are produced.

A well-known technique for separating oil from water in an aqueous mixture is to let the mixture stay in a container so that the oil settles on the surface and can then be removed, or to let the solid particles accumulate at the bottom of the container. A disadvantage of this technique is that. it. is relatively slow and is not suitable for industrial processes unless relatively large tanks are built for the decanting of the mixtures.

Filtering of the mixtures can also be done in the classic way using water-penneable filters through which the mixture is forced to pass, so that water passes through the filters but the oily and/or solid residues are retained by them. A disadvantage of this technique is that the filters become saturated quite quickly.

SUMMARY

An apparatus has been found and is an object of this disclosure, as defined in the attached claims, for separating water from an oil-water mixture, which can also be used to separate water from a mixture of solid particulate matter in water, or from a mixture of solid particulate matter with oil and water, which solves at least in part the aforementioned problems. Essentially, a motorized hollow roller is used which defines a lateral surface with through holes and which is covered externally by a filter, distinct and separate from the hollow roller, which is also permeable to water and configured to retain oily residues. According to the separation process of this disclosure, the motorized roller is rotated so that a portion of the filter separates the water from the mixture retaining oily and/or solid residues, and can be taken outside the mixture so that the filter can be cleaned by aspirating the oily and/or solid residues that impregnate it.

The apparatus and the process of this disclosure are more precisely defined in the attached claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of a washing system comprising a washing unit and a water separating apparatus according to an embodiment of this disclosure.

Figure 2 is a longitudinal sectional view of the washing system of figure 1, showing the distribution of a liquid in the water separating apparatus.

Figure 3 is a. front view of a water separating apparatus of figure 1.

Figure 4 is a sectional view of the water separating apparatus of figure 3 along the plane A- A, showing how the suction nozzles are positioned against the inner surface of the hollow roller. Figure 5 is an exploded view of the water separating apparatus of figure 3.

Figure 6 is a top view of the suction nozzles mounted above the suction pipe, fixed to a lid of the container of the water separating apparatus of figure 3.

Figure 7 is a sectional view along the plane A-A of the suction nozzles and the suction pipe shown in figure 6.

Figure 8 is a sectional view of a suction nozzle and its mechanical suspensions resting on the suction pipe delimited by the circle B.

Figure 9 is an exploded view of the suction nozzles and the lid of the container shown in figure 6.

Figures 10 and 1 1 are perspective views of the water separating apparatus of figure 3, according to a preferred embodiment.

Figure 12 is a sectional view of another embodiment of the water separating apparatus of figure 3 along the plane A-A, showing how the suction nozzles and the filter backwash nozzles are positioned.

Figure 13 is an exploded view of the water separating apparatus of figure 12.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

An illustrative embodiment of a washing system according to this disclosure is shown in figure 1. It shows the washing unit 12, with the related collection tank 13 for washing or purging liquid, and an apparatus for separating water from the washing or purging liquid connected to the collection tank 13. The separation apparatus is partially visible in figure 1, which shows the closed container 1, according to a preferred embodiment, and the air suction pipe 9.

The separation apparatus, according to the present disclosure, allows water to be recovered from the washing or rinsing liquid, which is typically an oil -water mixture, or a mixture that includes both solid particulate and oil in water. In general, therefore, it allows the water contained in the washing or purging liquid mixture to be separated from the oily and/or solid residues dispersed in it, so that the recovered water can be reused in the washing system itself, thus reducing the need for clean water and the quantity of discharged dirty water.

Figure 2 shows a section of the washing system of figure 1 in order to highlight how the washing liquid is arranged in the separation apparatus. In the following, the various parts of the separation apparatus will be illustrated with reference to figures 3 to 11.

The separation apparatus of the present disclosure comprises a hollow roller 2, preferably in the shape of a right circular cylinder, which defines a cylindrical lateral surface with through holes 3 which connect the inside with the outside of the hollow roller 2 itself, as shown in figure 4. The hollow roller 2 is motorized, for example by means of a functionally connected motor 15, so that it can be rotated around its central axis. On the outside of the lateral surface of the hollow roller 2, as shown in figure 5, a filter 14 is wrapped, distinct and separate from the hollow roller 2, which covers the through holes 3 on the lateral surface of the hollow roller 2 and is configured so as to let the water pass but to retain between its fibres the solid particulate matter and the oil contained in the mixture, when this is forced to pass through the filter 14. As can be seen in figure 2, the washing liquid which collects in the container 1 of the washing system is supplied to the separation apparatus so as to be introduced inside the motorized hollow roller 2, so that by gravity water passes throughout the filter 14 (not shown in figure 4) which is wrapped around the external lateral surface of the hollow roller 2 while the solid particulate matter and/or the oil of the washing liquid is retained between the fibres of the filter 14. The hollow roller 2 is positioned inside a container 1 so as to delimit a volume inside the hollow roller 2, into which the washing liquid to be filtered is introduced, and a volume outside the roller in which the water separated from the washing liquid is collected, wh ere the volume outside the hollow roller 2 is separated from the volume inside the hollow roller 2 by the filter 14, with the water of the mixture passing through the filter 14 by gravity while the filter 14 retains oily and/or solid residues.

As the washing liquid is fed into the hollow roller 2, the water contained in the washing liquid passes through the filter 14 by gravity and collects in a lower portion of the volume external to the hollow roller 2, while the solid and/or oily residues of the washing liquid are retained by the filter 14 itself. By moving the hollow roller 2 with the filter 14 impregnated with the residues collected in the washing liquid, the dirty portion of the filter 14 is brought to an upper area which is located above the free surface of the washing liquid contained in the separation apparatus, so that the impregnated portion of the filter 14 emerges from the washing liquid and is exposed to the air contained in the upper part of the container 1 of the separation apparatus.

The separation apparatus of the present disclosure also comprises a plurality of suction nozzles 5 which are positioned inside the perforated hollow roller 2 and are in contact with the internal surface of the hollow roller 2 so as to be able to suck up the solid and oily residues retained by the filter 14 when, thanks to the rotation of the motorized hollow roller 2, the dirty part of the filter 14 emerges from the washing liquid contained in the separation apparatus and is exposed to the air.

The air sucked in through the nozzles 5 passes from the outside of the hollow roller 2 to the inside of the hollow roller 2 exclusively through the filter 14, then through the through holes 3 in the lateral surface of the hollow roller 2 and finally enters the nozzles 5. The filter 14 is distinct and separate from the hollow roller 2 and is wrapped around the outside of the hollow roller 2, whilst the suction nozzles 5 are installed inside the hollow roller 2, and this is an arrangement that allows for easy replacement of the filter 14 by acting from the outside of the hollow roller 2. Furthermore, this configuration prevents the suction nozzles 5 from tearing the filter 14 even if they suck in a relatively large amount of air, which is desirable for thoroughly removing oily and/or solid residues from the filter 14, because the filter 14 rests against the outer surface of the hollow roller 2 while being sucked in. As a result, it becomes possible to use paperbased filters 14, which have a relatively low tear resistance, but are effective in retaining oily residues and are low cost.

Finally, thanks to this configuration, the suction nozzles 5 are never submerged by the washing liquid contained in the separation device, because the dirty part of the filter 14 from which to suck the solid and/or oily residues is lifted and brought outside the liquid itself close to the suction nozzles 5.

In figure 4 it is also shown that the container 1 has an outflow opening 6 defined on a bottom portion of the container 1, configured to drain water separated from the mixture and ready to be sent back to the washing unit, as well as an inflow- opening 7 configured to introduce the mixture to be filtered inside the hollow roller 2.

In the illustrated example, in which the container 1 is closed at the top and is not designed as an open tank, as would be possible even if not preferred, an air intake 8 is defined, configured to put the volume outside and above the hollow roller 2 in fluid communication with an environment outside the closed container 1, so as to allow the flow of air that is sucked in by the suction nozzles 5 so as to pass throughout the filter 14 impregnated with oily and/or solid residues, pushing the latter to detach from the filter 14 by proceeding in a centripetal direction. According to an aspect illustrated in figures 6 to 9, the suction nozzles 5 are mounted above a suction pipe 9, connectable to a suction pump 11, by means of mechanical suspensions 10 configured to keep the suction nozzles 5 in contact from the inside of the hollow roller 2 with the cylindrical lateral surface defined by it. With the mechanical suspensions, the suction nozzles 5 are pushed so as to remain in contact against the inside of the lateral surface of the perforated hollow roller 2, always ensuring a good seal of the suction nozzies 5 against the hollow roller 2 by sucking only the air that manages to pass throughout the through holes 3, carrying away solid and oily residues retained by the filter 14.

According to one aspect, the filter 14 for separating water from oil and/or particulate matter contained in the washing or purging liquid is made of a non-woven fabric, or of filter paper, or of a woven filter fabric.

With the separation apparatus described, water can be separated from an oil -water mixture, or from a mixture of solid particulate matter and water, or from a mixture of solid particulate matter with oil and water, through the following operations:

- the mixture to be separated is introduced into the hollow roller 2,

- water is allowed to percolate, on the bottom of the container 1 outside the hollow roller 2, which passes throughout the through holes 3 of the hollow roller 2 and which passes throughout the filter 14 wrapped on the lateral surface of the hollow roller 2, so as to retain in the filter 14 oil and/or solid particulate matter of the mixture to be filtered;

- the motorized hollow roller 2 is rotated on its central axis so as to bring portions of the filter 14 impregnated with oily and/or solid residues in correspondence with the suction nozzles 5, so as to be able to suck them up with the suction nozzles 5;

- in the lower part of the separation device, thus on the bottom of the container 1 which contains the perforated roller 2, the water that has been separated is collected and thus it can therefore be sucked up from the bottom of the container 1 and reused.

With the separation apparatus of this disclosure, a fabric web can be washed, in continuous and open mode, by separating the water from the mixture taken from the collection tank 13 of the washing unit, and by feeding the water, which has passed through the filter 14 and has been separated from the mixture, to the washing unit 12.

In one aspect, the hollow roller 2 is made by means of a perforated sheet rolled on itself so as to define a lateral surface of a right cylinder with a circular base. This solution is convenient because it is easier to bring the suction nozzles 5 into direct contact with the internal surface. However, the perforated hollow roller 2 can also have a truncated cone shape or a non-circular base.

According to one aspect, the through holes in the lateral surface of the roller define a total through area greater than 50% of the cylindrical lateral surface of the hollow roller 2 if it were full, i.e. without through holes 3. Preferably, the through holes 3 define a total through area greater than 60% of the area of the cylindrical lateral surface if it were full. It has been noted, from tests carried out by the applicant, that the suction efficiency of the nozzles 5 is too penalised if the ratio between the total area of the through holes 3 and the total lateral surface of the hollow roller 2 is less than 50%. The through holes 3 can be arranged in a row and aligned in a circumferential direction along the lines of the cylindrical lateral surface, or they can be made in staggered rows so as to increase the number of through holes 3 without jeopardising the solidity of the hollow roller 2 itself. According to an aspect illustrated in figure 2, the hollow roller 2 is placed in the container 1 so that its central axis is inclined with respect to an air-mixture separation surface to be filtered, and has a height, measured parallel to the central axis, such that the mixture contained in the container 1 wets a portion of the filter 14 from the inside along the entire height of the hollow roller 2, With this arrangement, the filter 14 is immersed in the washing liquid for the entire length of the direction of the cylindrical lateral surface, thus exploiting the entire size of the filter 14 and avoiding that there are parts of the filter 14 that are never wetted by the washing liquid to be filtered. An advantage of this arrangement consists in the fact that it is possible to extract the hollow roller 2 with the filter 14 to replace it without the washing liquid coming out of the container 1.

According to a less preferred aspect, the hollow roller 2 is arranged with its axis parallel to the free surface of the washing liquid contained in the appliance, but in this case the appliance must be emptied before opening it to replace the filter 14,

According to an illustrative embodiment shown in figures 12 and 13, alternative to the embodiment shown in figures 4 and 5, the separation apparatus may optionally be equipped with spray nozzles 16 for washing the filter 14 arranged in the upper part of the apparatus. These nozzles 16, mounted in fluid communication on a respective water inflow pipe 17, pass through the external wail of the container 1 passing through respective holes 18 in the upper part and are oriented against the filter 14 so as to spray, towards the inside of the roller 2, water conducted by the inflow pipe 17 from the outside of the roller 2. The suction nozzles 5, located inside the roller 2, are installed so as to be axially opposite the nozzles 16 so as to suck up the oily and/or solid residues that detach from the filter 14, preventing them from falling back into the mixture contained in the roller 2. The washing nozzles 16 prolong the useful life of the filter 14 because the oily and/or solid residues, which are retained by the filter 14 when the mixture passes through it passing from the inside to the outside of the roller 2, are pushed by the water jet of the nozzles 16 to detach from filter 14, which is then continuously cleaned.

According to one aspect, the water sent to the inflow pipe 17 can come from the same pump that supplies water to the washing unit of the washing system, or it can be directly supplied by a public water network.

Claims

1. A separating apparatus suitable for separating water from an oil-water mixture, as well as from a mixture of solid particulates and water, as well as from a mixture of solid particulates with oil and water, comprising: a container (1) configured to contain said mixture to be filtered, a hollow roller (2), defining a cylindrical or frusto-conical lateral surface with through holes (3) from the inside to the outside of the hollow roller (2), in which said hollow roller (2) is motorized so as to be rotated around its central axis; a filter (14) distinct and separated from the hollow roller (2), wherein said filter (14) is installed outside the hollow roller (2) so as to wrap said lateral surface from the outside of the hollow roller (2) covering said through holes (3), said filter (14) being configured to be permeable to water but to retain oil when an oil-water mixture is forced to pass throughout the filter (14); wherein said hollow roller (2) is positioned in the container (1) so as to define a first lower volume of said container (1) inside the hollow roller (2), said first lower volume (3) being intended to contain water of said mixture to be filtered, and a second lower volume (4) of said container outside the hollow roller (2), said second lower volume (4) being separated from the first lower volume by said filter (14) and being intended to contain water, which by gravity crosses the filter (14), separated from said mixture, a third upper volume of said container (1) inside the hollow roller (2), said third upper volume being above a free surface of said mixture to be filtered, a fourth upper volume of said container (1) outside the hollow roller (2), said fourth upper volume being separated from the third upper volume by said filter (14) and being configured to allow an influx of air from the outside of said container (1), a plurality of suction nozzles (5) which are positioned in the upper third volume inside said hollow roller (2) and which are in contact with an inner face of said lateral surface of the hollow roller (2), and which are configured to be functionally connected to a suction pump to suck air from the outside of the hollow roller (2), wherein the air sucked by the suction nozzles (5) goes from the outside of the hollow- roller (2) to the inside of the hollow roller (2) passing only through the filter (14) and then through the through holes (3) of the lateral surface of the hollow roller (2); wherein said hollow roller (2) is configured so as to be partially immersed in liquids of said mixture to be filtered and so as to rotate on its central axis to cany portions of said filter (14) internally wetted by said mixture to be filtered that passes through said through holes (3), wherein said portions of the filter (14) retain oil of said mixture, in correspondence with the suction nozzles (5); wherein said container (1) has an outflow opening (6) defined on a bottom portion of the container (1), configured to allow water separated from said mixture to flow out, as well as an inflow opening (7) configured to introduce the mixture to be filtered inside the hollow roller (2).

2. The apparatus for separating according to one of the previous claims, wherein said container (1) is closed at the top and also has an air intake (8), configured to put the fourth volume in fluid communication with an environment external to the closed container (I).

3. The apparatus for separating according to one of the previous claims, wherein said filter (14) for separating the water from the oil of said mixture is constituted by a non-woven fabric, or by filter paper, or by a filter woven cloth.

4. The apparatus for separating according to one of the previous claims, in which said hollow roller (2) is constituted by a perforated sheet metal defining a cylindrical lateral surface, in which the through holes define a total passing surface greater than 50% of the cylindrical lateral surface of the hollow roller (2), preferably greater than 60% of the cylindrical lateral surface of the hollow roller (2).

5. The apparatus for separating according to one of the previous claims, in which said suction nozzles (5) are mounted on a suction pipe (9), connectable to a suction pump, by means of mechanical suspensions (10) configured to maintain the suction nozzles (5) in contact from the inside of the hollow roller (2) against the lateral surface.

6. The apparatus for separating according to claim 5, comprising a suction pump (11) functionally connected to the suction pipe (9) to suck, with the suction nozzles (5), air from the outside of the hollow roller (2) throughout the filter (14) and throughout the through holes in the lateral surface.

7. The apparatus for separating according to one of the previous claims, wherein said hollow roller (2): it is placed in said container (1) so that its central axis is inclined with respect to a separation surface between air and mixture to be filtered; it has a height, measured parallel to the central axis, such that the mixture contained in said second volume wets a portion of the filter (14) along an entire height of the hollow roller (2).

8. The apparatus for separating according to one of the previous claims, comprising spray nozzles (16) mounted in fluid communication on a respective water inflow pipe (17), wherein said nozzles are arranged outside the roller (2) and are oriented so as to spray water against the filter (14) towards the inside of the roller (2), wherein said water is conducted from the inflow pipe (17), to detach said solid particulate and/or oil from the filter (14).

9. The apparatus for separating according to claim 8, wherein said spray nozzles (16) are aligned along a longitudinal direction of the water inflow pipe (17) and said nozzles (5) are aligned parallel to the spray nozzles (16).

10. The washing system for washing a fabric web in continuous and open mode, said system comprising: at least one washing unit (12) comprising a collection tank (13) for a washing or rinsing liquid; an apparatus for separating according to one of the previous claims functionally connected to said washing unit (12) to receive a mixture of water and oil, or of water and solid particulate, or of water with oil and solid particulate to be filtered, which is collected in said collection tank (13).

11. A process of separating water from an oil -water mixture, or from a mixture of solid particulates and water, or from a mixture of solid particulates with oil and water, comprising the following operations: providing and installing an apparatus for separating according to one of claims 1 to 9; introducing the mixture to be separated into the second lower volume (4) inside the hollow roller (2); allowing to percolate, into the first lower volume of the container (1), filtered water which has passed throughout holes in the cylindrical lateral surface of the hollow roller (2) and which has passed throughout the filter (14), and retaining in said filter (14) oil and/or solid particulates of said mixture; rotating said motorized hollow roller (2) on its central axis so as to bring portions of said filter (14), which retain oil and/or solid particulates of said mixture, in correspondence with the suction nozzles (5) of the separating apparatus; sucking up the oil and/or solid particulates of the mixture retained by the filter (14) using the suction nozzles (5); collecting, in the first lower volume (3) of the container (1), filtered water that has passed throughout the filter (14) and has been separated from the mixture.

12. A washing process of a fabric belt in continuous mode and in open mode, comprising the following operations: providing and installing a washing system according to claim 10; separating water from the mixture taken from the collection tank (13) of the washing unit according to the process of claim 11; feeding the filtered water, which has passed throughout the filter (14) and has been separated from the mixture, to the washing unit to wash said fabric belt.