GB2301425A

GB2301425A - Method and apparatus for treating a run of fabric with a vacuum

Info

Publication number: GB2301425A
Application number: GB9606282A
Authority: GB
Inventors: Walter Keller
Original assignee: Wet-Tex Maschinenbau GmbH
Current assignee: Wet-Tex Maschinenbau GmbH
Priority date: 1995-05-27
Filing date: 1996-03-26
Publication date: 1996-12-04
Also published as: BE1011427A3; ITMI961020A1; NL1002673C1; JPH08325923A; ITMI961020A0; DE19519551A1; GB9606282D0; IT1283045B1; FR2734582A1

Description

2301425 METHOD AND APPARATUS FOR TREATING A RUN OF FABRIC WITH VACUUM The

invention relates to a method for treating a run of fabric which is guided within a treatment housing by way of guide rollers, whereby vapours which arise are removed by a vacuum and are separated into gas and liquid, wherein the liquid may be returned into the treatment housing, in accordance with patent DE-P 44 36 746.5.

According to the basic patent, the run of fabric is guided inside a washing machine through a heated washing liquid. The mixture of gas and water forming inside the washing machine is removed to the outside and is then separated into a gaseous phase and a liquid phase. The liquid is returned into the washing machine. The hot gas is diverted unused. The washing liquid in the washing machine loses the thermal energy removed in this way, which leads to much cooling of the washing liquid with much energy loss. The gas diverted into the open pollutes the environment. During the suction of the liquid by means of a vacuum, a portion of the liquid is converted into the gaseous phase by the reduction of the pressure in the vacuum, and the associated lowering of the boiling point, and arrives unused with the energy located therein into the atmosphere with the remaining gas. Hitherto it was not possible to make the energy located in the gas easily usable.

During the drying of a run of fabric vapours arise which are removed to the outside by way of ventilators or suchlike. As a consequence of the removal of the vapours, extraneous air, in particular cold air, is drawn in, resulting in a worsening of the drying action. In particular, with the use of dry cylinders this measure is a disadvantage because in the process the dry cylinders cool down greatly.

With the additional invention a run of fabric is to be dried, with the object of the invention being to avoid the disadvantages of the known apparatuses and to create a method and an apparatus with which the energy expended is almost completely regained, the effect of the treatment is improved and the effect of the drying is increased.

The object is achieved in that to dry a textile web the run of fabric is guided by means of one of the several rotating rollers which are connected in series in the running direction of the run of fabric, in that the vapours are removed by a vacuum generator and are guided by way of a separator from which the gases are conducted by way of the vacuum generator and then returned into the treatment area in the exit region of the run of fabric of the last roller.

With the method in accordance with the invention the gases separated from the vapours are conducted by way of the vacuum generator.

An additional energy is to be used by the vacuum generator, for example the mechanical driving power of the engine, which lies between 10 and 100 KW. As a consequence of this additional energy, the gas in the vacuum generator is heated further because of the friction losses. The return of the additionally heated gas not only improves the energy balance, but it also leads to an improved effect of the treatment.

_ The gases returned into the treatment housing and heated in the vacuum generator are blown directly on to the run of fabric in the exit region of the run of fabric, for example by way of nozzles. The vapours which arise during the drying are in this way removed from the surface of the run of fabric, whereby the drying action is improved.

If the returned gases, or portions thereof, are guided against the running direction of the run of fabric from the exit region to the inlet area of the run of fabric through a heated flow channel which surrounds the rollers and is sealed with respect to the outside, then the vapours are blown away from the run of fabric over the entire length of the flow channel and, after leaving the flow channel, they can then in turn be drawn off together with the gases by the vacuum generator. The flow channel also improves the drying action.

The drying medium necessary for drying the run of fabric can be applied to the run of fabric by way of the rollers and/or by way of the heated flow channel.

If heated rollers are used, then a temperature balance occurs within the flow channel which almost equals the temperature of the returned gases. The gases form a superheated steam with the vapours which partially absorbs the vapours in order to saturate itself. The effect of drying is also substantially improved as a result of this measure.

If the inner wall of a double-walled sheet cover forming the flow channel is provided with baffles, turbulence occurs within the flow channel which leads to a further improvement of the effect of drying. A usable double-walled heated sheet cover has been previously described in DE-P 44 16 645.1. With the use of such a heated, double-walled sheet cover the rotating rollers can be unheated.

In the treatment of a run of fabric comprising textile fabrics, the gases and the vapours may be drawn off together from the inlet area of the run of fabric by way of suction tubes, by way of which the run of fabric may be guided.

In the treatment of a run of fabric comprising elastic knitted goods, the rollers may be constructed as rotating suction and/or sieve rollers. Prom a first suction roller the vapours and the gases can be drawn off through a sieve casing of the roller through the run of fabric into the interior of the roller and then led away axially to the outside. With the last roller the returned gases can be conducted entirely or partially axially into the interior of the roller and then by way of a sieve casing from the inside to the outside through the run of fabric into the flow channel. This measure also has an advantageous effect on the drying of the run of fabric. An advantageous development of the suction roller has been previously described in DE-P 44 36 745.7.

To improve the energy balance further, the invention provides that the gas removed from the vacuum generator may be introduced entirely or partially in is microfinely dispersed form into a heat exchanger provided with a water supply and the hot liquid resulting in the process is supplied entirely or partially to a user or is introduced entirely or partially into the treatment zone and the outgoing air which arises is conducted entirely or partially into the open.

In the treatment of the run of fabric a portion of the treatment medium is lost. This loss must be replaced through the addition of a fresh medium, for example fresh wash water. The hot gas which is branched off is introduced in dispersed form into the liquid bath of the heat exchanger or directly into the treatment medium. The heat contained in the gas is delivered almost completely to the liquid medium, introduced into the treatment zone or supplied to another user. The remaining, largely cooled air can be conducted promptly into the open. It can also be conducted entirely or partially into the treatment zone.

An apparatus for carrying out the method is provided by a treatment machine for treating a run of fabric which is guided inside a treatment housing by way of guide rollers, and to remove the forming vapours a removal apparatus is connected to the treatment housing, whereby the mixture of gas and liquid which arises is removed and separated. What is new and inventive for drying a textile web is that to guide and treat the run of fabric one or more rotating rollers are arranged behind each other, seen in the running direction of the run of fabric, that to remove the formed vapours and the returned gases a removal conduit is connected to a separator which is provided in an upper region with a gas removal conduit and in a base region with a liquid conduit, with the gas removal conduit being connected to a vacuum generator and the liquid conduit provided with a pump means being connected to a user and/or returned to the treatment housing, and that a gas return conduit is arranged between the vacuum generator and the treatment housing.

An additional inventive feature is that a branch conduit leaves the gas return conduit coming from the vacuum generator, which branch conduit is introduced into the base region of a heat exchanger provided with a supply of fresh water and having distribution plate with microfine openings, in that in the area of the distribution plate a removal conduit for hot liquid is provided and above the distribution plate an outgoingair conduit guided into the open is provided.

The method in accordance with the invention can be carried out most easily with the apparatus in accordance with the invention.

For a better understanding of the present invention, and to show how the same may be carried into effe ct, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 shows an arrangement for textile fabrics; Figure 2 shows an arrangement for elastic knitted goods; and Figure 3 shows a further development.

During treatment, in particular the drying of a run of fabric consisting of textile fabrics, according to Figure 1 a run of fabric 3 is guided by way of guide rollers 10 to 14 and furthermore by way of two unheated rollers 16 and 17 through a treatment housing 1 with insulated walls 2. The rollers 10 to 14 are freely rotatable and one or both of the rollers 16, 17 are provided with a rotation drive in order to set the rollers rotating and thus drive the run of fabric. The fabric inlet 4 of the run of fabric 3 is introduced into the treatment housing 1 by way of a surge tank 6 which comprises a heatable, double-walled housing 7 with a liquid filling 8 and an overflow 9. Within the liquid filling 8 there is a first guide roller 10 for the run of fabric 3. Furthermore, guide rollers 11 to 13 are provided. For guiding and treating the run of fabric 3 the two unheated, rotating rollers 16 with roller shaft 18 and the roller 17 with roller shaft 19 are adjacent to the guide rollers. Heated rollers can also be used. By way of an additional guide roller 14, the outlet end 5 of the run of fabric 3 is removed from the treatment housing 1 by way of a gastight opening 15 on the outlet side and is guided further. The rollers 16 and 17 are each surrounded by a heatable, doublewalled sheet cover 20 and 21 (according to DE-P 44 16 645.1), which form a sealed flow channel 25 with lip seals 22 to 24. The inner sides of the sheet covers 20, 21 have baffles. The lip seals 22 and 23 are arranged in the transition area of the run of fabric from the roller 16 to the roller 17 and the lip seal 24 is arranged in the outlet area of the run of fabric 3 from the roller 17. The end at which the run of fabric 3 enters into the flow channel 25 is open. Between the guide rollers 12 and 13 a suction tube 26 with suction opening 31 is provided to the left of the run of fabric 3 and a suction tube 27 with suction opening 30 is provided to the right of it. Branch channels 28 and 29 are connected to the suction tubes 26, 27, which branch channels are connected to a suction conduit 32.

The suction conduit 32 is connected tangentially to a separator 33. A liquid conduit 36 with pump 37 extends from a base connection piece 34 of the separator 33. A gas removal conduit 38 extends from a top connection piece 35 of the separator 33, the conduit 38 being introduced into a vacuum generator 39 with drive 40. The gas additionally heated here is introduced by way of a gas return conduit 41 into a distribution box 42 with exit nozzles 43 directed to the run of fabric 3. The invention is not restricted to the exemplary embodiment shown. It is conceivable to carry out the method with only one roller.

During the treatment, in particular the drying of a run of fabric 3 comprising elastic knitted goods, according to Figure 2 between the guide rollers 13 and 14, two rollers 48 and 52 with sieve covers 49 and 53 as well as an intermediate guide roller 44 are provided. The rollers 10 to 14 are freeiy rotatable and one or both of rotating rollers 48, 52 are provided with a rotation drive. Between the guide roller 14 and the outlet-side opening 15 an additional guide roller 45 is provided. The roller 48 is constructed with a sieve casing_49 as suction roller according to DE-P 44 36 745.7 and the roller 52 with sieve casing 53 is constructed as a sieve roller. The roller 52 can be heated and/or unheated. Above the rollers 48 and 52 a heatable, double-walled sheet cover 46 (according to DE-P 44 16 645.1) is provided, which is adapted to the rollers and thus forms a flow channel 75. Here also the inside of the sheet cover 46 is provided with baffles. In the outlet area of the run of fabric 3 a -B- lip seal 47 is provided. The roller 48 is provided with a roller shaft 50 and the roller 52 with a roller shaft 74. In the area of the roller shaft 50 an axial suction conduit 51 is provided and in the area of the roller shaft 74 an axial supply conduit 54 is provided, to which a branch conduit 55 is connected, extending from the gas return conduit 41. Valves 56 and 57 ensure a controlled distribution of the returned gases. Below the rollers 48 and 52 there is a base pan 58.

The invention is not restricted to the exemplary embodiment here either because it is conceivable to carry out the method with only one roller.

All rollers 16, 17 and 48, 52 are equipped with sealed front walls, not shown. It is easily possible to use suction and/or sieve rollers also in the exemplary embodiment of Figure 1.

The flow channels 25 and 75 are fully sealed for the gases and vapours from the inlet area of the gases 76 and 77 to the outlet area 78 and 79 so that an even flow of the gases and vapours through the flow channels 25, 75 is ensured.

With the design according to Figure 1 the gases and vapours leave the flow channel 25 toether and arrive by way of the area 78 into the area of the suction tubes 26 and 27. From there they are drawn by means of a vacuum through the suction openings 30, 31 into the removal conduit 32 and arrive from there into the separator 33. Here the gases and liquid are separated from each other. The separated water arrives by way of the base connection piece 34 into the liquid conduit 36 with the pump 37 and is supplied to an additional user. The separated gas is drawn from the separator 33 by way of the top connection piece 35 and the gas removal conduit 38 into the vacuum generator 39, is heated up there and is introduced by means of the gas return conduit 41 into the distribution box 42.

The nozzle openings 43 are aligned over the entire width of the run of fabric 3 so that the returned gases are blown on to the run of fabric, evenly distributed over its entire width. From here the gases arrive in an even turbulent flow together with the vapours through the flow channel 25 into the outlet area 78.

In the design according to Figure 2 the returned gases are introduced by way of the gas return conduit 41 and the branch conduit 55 into the treatment housing 1. By means of the valves 56, 57 the partial quantities of gas can be distributed in any way to the conduits 41, 55. In the exemplary embodiment according to Figure 2 a portion of the gases is introduced by way of the distribution box 42 and by way of the outlet nozzles 43 on to the run of fabric 3 and thus into the flow channel 75. The remaining portion of the gases arrives by way of the branch conduit 55 into the axial supply conduit 54 and from there by way of the sieve casing 53 into the flow channel 75 which is fully sealed from the inlet area 77 to the outlet area 79. Together with the vapours which form, the gases are drawn by way of the sieve cover 49 of the roller 48 into the interior of the roller and thedby way of the axial suction conduit 51 into the branch conduit 32. Further treatment then takes place as already described above.

According to Figure 3, a portion of or all of the gas heated in the vacuum generator 39 is introduced by way of a conduit 63 into the base region of a heat exchanger 66 filled with water. The tube 64 extending over the heat- exchanger base is provided with ejection nozzles 65. Valves 59 and 60 allow a controlled distribution. The water, for example fresh water, is introduced by way of a conduit 67 with valve 68 into the heat exchanger 66. A distributor plate 69 with microfine openings ensures a dispersion of the gas with the fresh water, with an optimal thermal transmission from the gas to the fresh water. The heated water is conducted by means of a conduit 73 to an additional user. By means of the conduit 70 existing outgoing air is conducted into the open. The outgoing air can also be introduced by way of a conduit 71 into the gas return conduit 41. Valves 61 and 62 ensure an appropriate distribution.

When the valves 60 and 61 are closed and the valve 59 is open the gas leaving the vacuum generator 39 is returned completely into the treatment housing 1. when the valve 59 is closed and the valve 60 is open the gas is introduced completely into the heat exchanger 66. The valves 59 and 60 can be adjusted in such a way that portions of the gas are introduced into the treatment housing or into the heat exchanger 66. When the valve 62 is open and the valve 61 is closed the outgoing air is conducted completely into the open. When the valve 61 is open and the valve 62 is closed all the outgoing air is introduced into the gas return conduit 41. The outgoing air can also be removed partially by way of the conduits 70 and 71 with appropriate adjustment of the valves 61, 62.

Claims

1. A method for treating a run of fabric which is guided inside a treatment housing by one or more guide rollers, whereby vapours which arise are removed by a vacuum and are separated into a gas component and a liquid component, wherein the run of fabric is guided by one or more rotating rollers arranged in the running direction of the fabric, the vapours are removed by a vacuum generator, are separated by a separator, from which the gas component is conducted by the vacuum generator and returned into the treatment housing in the outlet area of the run of fabric of the last rotating roller.

2. A method according to claim 1, wherein a liquid component from the vapour is supplied to an additional user and/or returned to the treatment housing.

3. A method according to claim 1 or 2, wherein the returned gases are carried against the running direction of the run of fabric from an outlet region to an inlet region of the run of fabric through a heated flow channel which substantially surrounds the rotating rollers and is sealed to the outside, and after leaving the flow channel are removed together with the vapours which have formed.

4. A method according to any one of claims 1 to 3, wherein the returned gases are sprayed on to the run of fabric by nozzles.

5. A method according to any one of claims 1 to 4, wherein the gas removed from the vacuum generator is returned entirely or partially into the treatment housing.

6. A method according to any one of claims 1 to 5, wherein the gas removed from the vacuum generator is introduced entirely or partially into a heat exchanger provided with a water supply and the hot liquid which results in the process is supplied entirely or partially to a user and the outgoing air which arises is conducted entirely or partially into the open.

7. A method according to any one of claims 1 to 6, wherein the rollers are operated without their own heating.

8. A method according to any one of claims 1 to 6, wherein the rollers are operated with their own heating as dry cylinders.

9. A method according to any one of claims 1 to 6, wherein at least one roller is operated without heating and at least one further roller is operated as a heated dry cylinder.

10. A method according to any one of claims 1 to 9, for treating a run of fabric comprising textile fabrics, wherein the vapours in an inlet region of the run of fabric are drawn off on to a front roller by means of one or more suction tubes, with the run of fabric extending over the suction tubes.

11. A method according to any one of claims 1 to 9, for treating a run of fabric comprising of elastic knitted goods, wherein with a construction of the rollers as suction or sieve rollers the vapours are removed axially out of a first roller and the returned gases or portions thereof are introduced axially into a second roller.

12. An apparatus for treating a run of fabric, which apparatus comprises guide rollers for guiding the run of fabric inside a treatment housing, wherein one or more rotating rollers are arranged after each other in the running direction of the fabric between the guide rollers to guide and treat the run of fabric, the apparatus further comprising a removal conduit to remove the formed vapours extending from the treatment housing and connected to a separator, which separator is connected at a top region to a gas removal conduit and at a base region to a liquid removal conduit, wherein the gas removal conduit is connected to a vacuum generator and the liquid removal conduit provided with a pump means may be connected to a user, and wherein a gas return conduit is arranged between the vacuum generator and the treatment housing.

13. An apparatus according to claim 12, wherein the housing end region of the gas return conduit is provided with a distribution box having outlet nozzles, the outlet openings of which are directed to the run of fabric.

14. An apparatus according to claim 12 or 13, for treating a run of fabric comprising textile fabrics, wherein the rotating rollers, forming a flow channel, are each surrounded with clearance by a heatable, double-walled sheet cover provided with inner baffles, with the sheet cover of a first roller in the area of the end region of the run of fabric and the sheet cover of a second roller both at the inlet end region and at the outlet end region of the run of fabric each being provided with a lip seal.

15. An apparatus according to any one of claims 12 to 14, wherein there is associated with the run of fabric in the region before the first rotating roller one or more suction tubes which are connected to the removal conduit by way of branch channels.

16. An apparatus according to claim 12 or 13, for treating a run of fabric comprising elastic knitted goods, wherein the rotating rollers, forming in the upper part a flow channel, are surrounded with clearance by a heatable, double-walled sheet cover which is adapted to the rollers and has inner baffles, wherein the lower part of the rollers is substantially covered by a base pan and wherein between the rollers in a lower region an additional guide roller is provided.

17. An apparatus according to claim 16, wherein the rotating rollers are constructed as suction or sieve rollers and a front roller is provided with an axial suction conduit and a rear roller is provided 5 with an axial supply conduit.

18. An apparatus according to claim 17, wherein a branch conduit extends from the gas return conduit, which branch conduit is conducted to the axial supply conduit of the roller and wherein the gas return conduit and the branch conduit are each provided with a valve means.

19. An apparatus according to claim 13 or any one of claims 14 to 18 when appendant to claim 13, wherein the distribution box is accommodated within the sheet cover.

20. An apparatus according to any one of claims 12 to 19, wherein an additional branch conduit extends from the gas return conduit, which additional branch conduit is introduced by means of a perforated tube into a base region of a heat exchanger provided with a supply of fresh water and with a distribution plate having openings, wherein in the area of the distribution plate a removal conduit for hot liquid is provided.

21. An apparatus according to claim 20, wherein above the distribution plate an outgoing-air conduit guided into the open is provided.

An apparatus according to claim 20 or 21, wherein the distribution plate is provided with microfine openings.

23. An apparatus according to claim 21 or 22, wherein a branch conduit extends from the outgoing-air conduit, which branch conduit is connected to the gas return conduit.

24. A method for treating a run of fabric which is guided inside a treatment housing by way of one or more guide rollers, whereby vapours which arise are removed by means of a vacuum and are separated into a gas component and a liquid component, wherein the liquid component may be returned to the treatment housing, characterized in that for drying a textile web the run of fabric is guided by one or more rotating rollers which are connected in series in the running direction of the run of fabric, the vapours are removed by a vacuum generator, are guided by way of a separator, from which the gases are conducted by way of the vacuum generator and then returned in the outlet area of the run of fabric by the last roller into the treatment area.

25. Apparatus for carrying out the method according to any one of claims 1 to 11 or 24, comprising a treatment machine, for treating a run of fabric which is guided inside a treatment housing by way of guide rollers, and to remove the forming vapours a removal apparatus is connected to the treatment housing, wherein to dry a textile web, between the guide rollers one or more rotating rollers are arranged after each other, in the running direction of the run of fabric to guide and treat the run of fabric, wherein to remove the formed vapours a removal conduit is connected to a separator which is connected at a top region to a gas removal conduit and at a base region to a liquid removal conduit, with the gas removal conduit being connected to a vacuum generator and the liquid conduit provided with a pump means being connected to a user and/or returned to the treatment housing, and wherein between the vacuum generator and the treatment housing a gas return conduit is arranged.

26. An apparatus substantially as hereinbefore described with reference to, and as illustrated in, the 3S accompanying drawings.

27. A method for treating a run of fabric substantially as hereinbefore described, with reference to the accompanying drawings.

162 Amendments to the claims have been filed as follows CLAIMS 1. A method for treating a run of fabric which is guided inside a treatment housing by one or more guide rollers, whereby vapours which arise are removed by a vacuum and are separated into a gas component and a liquid component, wherein the run of fabric is guided by one or more rotating rollers arranged in the running direction of the fabric, the vapours are removed by a vacuum generator, are separated by a separator, from which the gas component is conducted by the vacuum generator and returned into the treatment housing in the outlet area of the run of fabric of the last rotating roller.

2. A method according to claim 1, wherein a is liquid component from the vapour is supplied to an additional user and/or returned to the treatment housing.

6. A method according to any one of claims 1 to 5, wherein the gas removed from the vacuum generator is introduced entirely or partially into a heat exchanger provided with a water supply and the hot liquid which r7 results in the process is supplied entirely or partially to a user and the outgoing air which arises is conducted entirely or partially into the open.

7. A method according to any one oil claims 1 to 6, wherein the rollers are operated without their own heating.

12. An apparatus for treating a run of fabric, which apparatus comprises guide rollers for guiding the run of fabric inside a treatment housing, wherein one or more rotating rollers are arranged after each other in the running direction of the fabric between the guide rollers to guide and treat the run of fabric, the apparatus further comprising a removal conduit to remove the formed vapours extending from the treatment housing and connected to a separator, which separator is connected at a top region to a gas removal conduit I's and at a base region to a liquid removal conduit, wherein the gas removal conduit is connected to a vacuum generator and the liquid removal conduit provided with a pump means may be connected to a user, and wherein a gas return conduit is arranged between the vacuum generator and the treatment housing in the outlet area of the run of fabric of the last rotating roller.

16. An apparatus according to claim 12 or 13, for treating a run of fabric comprising elastic knitted goods, wherein the rotating rollers, forming in the upper part a flow channel, are surrounded with clearance by a heatable, double-walled sheet cover which is adapted to the rollers and has inner baffles, wherein the lower part of the rollers is substantially covered by a base pan and wherein between the rollers Ick in a lower region an additional guide roller is provided.

17. An apparatus according to claim 16, wherein the rotating rollers are constructed as suction or sieve rollers and a front roller is provided with an axial suction conduit and a rear roller is provided with an axial supply conduit.

20. An apparatus according to any one of claims 12 to 19, wherein an additional branch conduit extends from the gas return conduit, which additional branch conduit is introduced by means of a perforated tube into a base region of a heat exchanger provided with a supply of fresh water and with a distribution plate having openings, wherein in the area of the distribution plate a removal conduit for hot liquid is provided. 21. An apparatus according to claim 20, wherein above the distribution plate an outgoing-air conduit guided into the open is provided. 30 22. An apparatus according to claim 20 or 21, wherein the distribution plate is provided with microfine openings. 23. An apparatus according to claim 21 or 22, wherein a branch conduit extends from the outgoing-air conduit, which branch conduit is connected to the gas return conduit.

26. An apparatus substantially as hereinbefore described with reference to, and as illustrated in, the ML-A accompanying drawings.