DE1635263A1 - Method and device for drying fabrics - Google Patents

Description

Dipl .-! Ng. August Boshart, _e ", _ß , Dipl.-Ing. Walter Jackisch 1 D 0 0 4 0 J Patent Attorneys _, 2 October 1, 1966 Stuttgart-N, Menzelstrasse 4Ö

Metal-Tech Inc., A 29 295 wn

a corporation organized under

the laws of the State of Maine, USA

of Biddeford, County of Cumberland and

State of Maine, United States of America

Method and device for drying fabrics.

The present invention relates to a method for drying moist tissues on a with predetermined speed rotating Slebflache pass through a drying atmosphere lying down. To the The subject matter of the invention also includes a device for carrying out such a method.

In addition to the typical application mentioned, the invention is also applicable to the drying of paper webs and other film or tape-like objects applicable. The usual for such drying processes devices used work with a larger number of e.g. twenty to thirty smooth-surfaced, steam-heated cylinders or other vessels over which the fabric to be dried or the like is running. Such Facilities are associated with high investment costs,

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mainly because of the extensive radiators and because of the large amount of space required.

For drying porous webs of material, rollers with an openwork jacket connected to a hot air circuit have also already been used. However, the free passage area of such rolls in rough alignment is known to be only about 50 % of the total circumferential area, so that when flowing radially through the jacket there is a considerable pressure loss in the drying air flow, which in turn is the di 'available for the actual drying process when penetrating the porous material. slope reduced. The known devices of this type therefore require Druoklufteraeuger of considerable power for reasonably satisfactory work.

The object of the invention is to create a method and a device of the type mentioned above, with which fabrics and porous material webs of the most varied

Species with low power requirements for rooting the Drying agent as well as with little investment and Space that can be effectively dried. The inventive method for solving this problem

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is mainly characterized by the fact that a tissue surface enters the tissue at high speed penetrating stream of moisture-enriched air with a temperature of at least ISO c and a comparatively low overpressure supplied is and that of the circulated air flow during operation, a moist partial air flow with the supply of a corresponding fresh air flow is branched off. The improved effectiveness of such a device is based sum tell on the use of the better heat storage capacity and heat transfer capacity of one with Liquid-enriched gas compared to a substantially moisture-free state of the gas. On the other hand, the moisture content of the drying gas makes itself felt in the method according to the invention Hardly noticeable disadvantageous, because the ongoing withdrawal of a moist partial flow means that there is sufficient distance is maintained from the saturation state in the drying gas.

Paa method according to the invention is particularly also suitable for step-by-step drying with the help of several drying units, which of the fabric to be dried are run through one after the other. One for this case

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particularly suitable procedure according to the invention is that the air flow supplied to the fabric in the first drying unit passed through in particular is heated to a temperature of about 26o ° C by means of a gas-heated infrared heater and that the dem Air flow supplied to the tissue in the drying units subsequently passed through a lower temperature having.

Another development of the method according to the invention consists in the fact that the effective width of the circumferential screen surface automatically corresponds to the respective width of the drying fabric is adjusted during its passage. One procedure is particularly recommended here such that the effective width of the circumferential screen surface is greater than that by such an amount Width of the continuous fabric is kept that on both sides of the fabric edges a flow around with simultaneous Penetration of the edge areas of the fabric, sufficient space for the sieve surface directly penetrating part of the suffestx'ora. on In this way, not only can the entire flow cross-section and thus the drive power be optimally utilized for the circulation of the air flow for

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drying, but also a particularly effective and even drying over the entire web roll reach.

The device according to the invention for carrying out a drying process of the type described is mainly characterized in that a screen roller is provided as the support and / or drive member for the fabric to be dried, the roller jacket of which has a free transition area of at least 85 % and voi based on the entire initial flow rate. ssisga has 90 % . Optimal utilization of the drying air flow can be achieved in particular by the fact that the flow resistance of the perforated casing of the screen roll is less than 1 % of the flow resistance for the drying air flow when it penetrates the fabric lying on the screen roll. It is also advisable to work with the largest possible angle of wrap around the fabric running through the screen. A specific embodiment of the device according to the invention consists in that, in order to set an angle of wrap of the fabric passing through, in relation to it

WM H t / f * d * Wf fof JSPf_ on the screen roll zwer ^ ~ ⁱ ungswalzen guide are provided, the

mutual distance et via double the Gewabos strength and

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their distance from the perimeter of the Walsenmanfceli; © twa corresponds to the simple gevie starch.

Essential for the device according to the invention '.xh above all the specified size of the free radial passage area of the Siebftalza. Can be rorgang the drying air Insgesanit with geringem- pressure gradient performed Lstztores lianas - HisMurch the pressure loss when flowing through the Walsenniantels before or after the actual Troelumgo process (actual this dar Struomngsrichtung föhhitngig.) / Ä ^ ~ 3SS "ähv Uaiwäls ·. In most cases only ¹ nouh of the permeability of the to be dried (laweböu from and 1st from the S '; speed of rotation within the fabric , which is sufficient for the drying process to then take effect wet Tel! airflow facilitates what erflndungsgemäS the arrangement of a provided with corresponding variable throttle bodies, opening out from the tlberdruckrauw in the outside air branch channel is sufficient experience, is obtained for most applications an effective drying at branching off a teit-air stream of about 20%.

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The invention is further based on an exemplary embodiment explained, which is shown in the drawings. Herein shows

2 shows a front view of a drying device according to the invention in partial section,

FIG. C shows a sectional view along line II-II in FIG. 1, FIG. 1 shows a modification of the drying device with the opposite direction of the air flow in

anslcht according to FIG. 2,.

Fig. £ an enlarged bar position of the adjustment device for the roller edge in the device according to the preceding figures, looking parallel

Eur roller axis and
FIG. 5 shows a partial view of the device according to FIG. 4 with a viewing direction transverse ¹ to the roll axis.

The drying device 20 shown in FIGS. 1 to 3 is fastened to a foundation surface 21 and housed in a building 22. The circulating air flow female housing 23 of the drying device is relatively starkwendlg formed _p wherein the GahEusewandungen of sheet metal panels having an average insulating layer 25

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are built up in several layers. Ira lower area of the Housing triangle wall 27 is a. Inlet opening 26 and preferably the latter opposite in the lower Area of the housing front wall 29 has an outlet opening 28 arranged for the continuous tissue. The ceiling and the side walls of the housing are marked with 31 resp. 32, 33 Draws.

In the lower area of the housing space, a screen roller 34 is arranged, the casing 35 of which is provided with end sections 36 and 37 open on both sides and consists of sheet metal strips 38 which are arranged in a radially upright position and are bent in a honeycomb shape or connected to one another. The latter form comparatively solid and narrow longitudinal edges 39 and 40 on the outer and inner surface of the roll shell 33 «. The spaces 42 of the sheet metal strips 38 define a free, radial passage area of the roll shell, which is at least 83 % and preferably 90 % of the total middle Uinfangsfläche of the roll shell corresponds. The honeycomb structure of the roll jacket has sufficient strength to be able to carry and drive a fabric 44 running over the screen roll without impermissible bending and torsion.

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The roll shell 35 is at both ends by one Spoke flange 45 or 46 with one in bearings 48 and 49 arranged shaft 47 coaxially firmly connected. Below the screen roller are guide rollers 51 and 52 with about twice the size inside the housing Strength of the fabric 44 corresponding mutual distance and with one of the simple fabric hardness corresponding Placed at a distance from the outer surface of the screen roller. «The fabric runs in the drying device from the Inlet opening 26 via the guide roller 52, the Circumference of the screen roller and the guide roller 51: on the outlet opening 28, wherein between the fabric and the screen roller on a circumferential angle of at least 350 ° bai set accordingly Tension of the tissue occurs.

The bottom of the housing 23 is supported by two drop flaps *!

54 and 55 formed with joints 56 and 57 am Frame 24 are attached. For the drop flaps there is one consisting of pressure cylinders 58 with piston rods 59 Slewing drive is provided, which via DruckmittelIeItungen 60 controllable 1st. With the drop flaps, which are easy to open, the screen roller with its guide rollers is in place for inserting a tissue as well as for maintenance and repair

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conveniently accessible.

Inside the housing 23 of the drying device is> furthermore a circulation device 62 for generating ice arranged circulating air flow. The circulating device preferably comprises two fans 63, 64 with suction openings 65-66 and exhaust openings 67-68. The fans are arranged from outside the housing 23 Motors 75 »76 Ubsr One V-belt drive each 72, 73, 7 * and shafts 69 and 70, respectively. in the Baiapielsfall were GeblUsö used, the one Delivery pressure of 12.7 cm WasseruUule an air stream of 0.65 nr / min per cm of dryness area. The fans 63 and 64 kitanen according to FIGS. I and 2 above the screen roller 34- are arranged «so that the exiting Air flow is directed downwards directly against the outer surface of the screen roller and after penetrating the to be dried Fabric 44 and the permeable roller jacket 35 over the interior of the screen roller and its open on both sides Ends back to the suction side of the blowers.

In Fig. 3 the reverse flow direction is indicated, the blowers directing the exiting air stream downwards into the open ends of the screen roller 34 and following it

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Suck through the roller jacket 35 and the tissue to be dried again. In the last-mentioned mode of operation, the air flow penetrating the lime shell forms an air cushion 71 between the WalsenauSenfläehe and the fabric, the latter being kept at a distance from the solid parts of the roll shell. Bies is particularly advantageous when treating colored fabrics. If necessary, an axial fan with a tubular housing and the same connection flanges on both sides can advantageously be used for air circulation, whereby the reversal of the direction of flow can be carried out in a simple manner by installing the fan with the same connection elements on both sides.

Xm the exhaust duct of both fans are air filters 7i> or 79 arranged. These filters are accessible for maintenance through a flap 80 in the front wall 29 of the housing.

The air flow is guided between the fans 63, 6H and the screen roller 3 ^ via a belt housing 82, the upper part of which, bounded by the inclined walls 83, 84, is connected to the discharge openings of the fan via passages 87, 88. In the lower part of the LeitgohUuses are opposite, the cross-section of the

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Screen roll adapted openings 35, 86 ve ^ g-s see. In the embodiment according to FIGS. 1 and 2 , the interior 89 of the Leitgeh & uses forms an overpressure cabin? _f into which the fans introduce a large amount of air and bring it into contact with the outer surface 90 of the permeable tissue Hh. The space 91 between the solenoid housing 82 and your outer housing 23 of the drying device forms a vacuum chamber, Ubar which flows back the air emerging from the interior of the screen roller to the suction side of the blower »

Into the flow path of the air within the housing 23 a heater 93 is also arranged, which welohsr the gcsgen the fabric strömend® brings air to © ine of about 150 ° C. In the example, the Heater 93 made up of two heat exchangers 94 and 95 * the "fet Via inflow and drainage pipes 96, 97 with one Heating steam source are connected. As a heater, e.g. a gas-heated infrared heater can also be used. The latter is particularly recommended when complete Drying of the fabric is to be achieved and the drying device 20 is part of a multi-part ·! Dry battery is. In the case of a dry cell battery consisting of three units, the treatment air can e.g. in the first unit be heated to about 26o ° C, by about half of the

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tissue present at room temperature remove. The second and third from de »! Tissue traversed unit can then as in the present Working embodiment with an air temperature of about 150 ° C, with the remaining moisture is removed without damaging the tissue. In the mode of operation of FIGS. 1 and 2, the heater is 93 arranged in the Ubardruckkaiinnar, in the operating mode after Fig. 3Jedoah because of the uragäkeiirtan direction of the air afcroma in the vacuum chamber.

While the Goviebo ¹ ^ the i'ro-ukeneinrichfcung ai with one to pull through the screen roller at a speed of aB about 45 m / s © c, the air penetrating the fabric is saturated with moisture, which reduces the heat storage and the thermal efficiency the air aunUchsfc increased. However, in order to maintain further moisture removal from the fabric by the circulating air flow, a certain amount of moisture must be continually removed from the fabric. For this purpose, according to Flg. 2, a branch channel 99 is provided which, starting from a connection opening 100 in the upper section of the cable housing 82, extends over a connection line 102 to one of the drying equipment

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remote location, preferably outside the building wall 22 opens into the outside air. By means of a throttle valve 103 arranged in the branch duct 99, the moist partial air flow leaving the overpressure rough is set to approximately 20 % to 25 % of the total air flow. The regulation of the throttle valve position can be done manually or automatically with the help of suitable measuring instruments. In the area of the negative pressure space in the rare walls 32, 33 of the housing 3 suction openings 104 and 105, respectively, through which a dry air flow from the atmosphere corresponding to the exiting, moist partial air flow enters the housing 23. Suitable throttle devices 106 and 107, which can be regulated manually or automatically, are also provided for the extraction openings.

The screen roller has a device 109 for adjustment the effective roller width to the respective width of the fabric passing through. The one during the revolution The device operating the screen roller comprises two disc-shaped flanges 110, 111, the circular edges of which or 113 fitted exactly and sealingly into the roll shell 35 and telescopically slidable into one another Htflsen Il4 and 115 are connected to the two open ends of the screen roller. The inside of the adjacent sleeve

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lying area of the flanges 110 and 111 is perforated, while the surface of the sleeves itself is uninterrupted. As a result, the effective section of the roll shell connected to the open ends of the screen roll is determined by the distance between the flanges 110-111.

Experience has shown that the edges of a fabric have a denser structure than its central surface area, which results in difficulties for uniform drying of the fabric passing through over the entire width. In the drying device according to the invention, the flanges 110, 111, which determine the effective section of the screen roller, are adjusted in the axial direction of the roller in such a way that a width of about 13 cm is maintained between the edges of the fabric HH and the flanges on both sides. In this way, the outermost edge areas of the tissue are not only penetrated by the dry air stream, but also flowed around it, which, as experience has shown, results in an increased drying effect precisely in this area.

The flanges 110 and 111 sit with concentric openings 117 or 118 on the ho \ formed and with longitudinal slots

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»120 provided shaft 4-7 of the screen roller. To recruitment or axial displacement of the flanges, a device 122 is provided «which two parallel arranged, about Sprockets 125, 126, 127, 128 running and over extending the entire length inside the hollow shaft 47 Chains 123, 124 has. The sprockets mentioned are outside the ends of the shaft 47 in stationary bearings 150, 131 stored. The common shaft 134 of the at one End of the hollow shaft 47 arranged sprockets 1st via a further chain drive 135 with one on one The drive motor 132 arranged on the housing console 133 and reversible in the direction of rotation is coupled (see also Fig. 4 and 5)

The flanges 110 and 111 are each through a one of the longitudinal slots II9 or 120 reaching through bar 137 or 138 each with an associated, K in the hollow shaft 47 slidably mounted ring connected, of which the latter in Flg. 4 the front ring 140 is visible. Each of these Rings is also in engagement with a respective claw 136 or 139 ″, both of which on the opposite Sections of the chains 123, 124 are attached symmetrically to the broad center of the screen roller. With the help of this Device, the flanges 110 and 111 in the axial direction

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in opposite directions while maintaining their symmetrical position can be moved to the broad center of the screen roller by appropriate control of the drive motor 152.

When the drying device is operated, a den Dimensions of the flow cross-section and the fan power corresponding large amount of heated air closed way via the fan 63, 64 and the Heater 93 and over the fabric 44 to be dried and the screen roller 34 circulates. The pressure difference Zwlscpfin The overpressure and underpressure space essentially only depends on the permeability of the fabric and the strength of the branched off air flow.

In the reverse direction of flow according to FIG. 3 a moisture content of the circulated air is removed by exiting a moist partial air stream from the housing openings 104 and 105, which are shown in FIG this pail lie in the area of the overpressure space. the The corresponding amount of fresh air is then transferred to the Unterdruokraum opening channel 99 sucked. The regulation of the partial air flows takes place as in the operating mode Flg. 1 and 2.

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Claims (21)

Λ35163 METAL-TECH.INC. A 29 295 wn a Corporation organized under the laws of the State of Maine, USA of Biddeford, County of Cumberland and State of Maine United States of America claims 1. Method of drying wet tissues on a at a predetermined speed pass through a drying atmosphere lying around the circumferential sieve surface, thereby characterized in that a fabric surface a stream of moisture penetrating the tissue at high speed enriched air with a temperature of at least 130 ° C and comparatively low overpressure is supplied and that of the circulating air flow in the running Operate a moist partial air stream under Supply of a corresponding prischluftstronies is branched off. - 2 109817/0 3 30 2. The method according to claim 1, characterized in that that the supply pressure of the air flow ata tissue is about 13 cm water column amounts to. 3 · The method according to claim 1 or 2, characterized in that the air flow at Penetration of the tissue up to a predetermined state of equilibrium Moisture is saturated and that as a substitute for the diverted, moist partial air flow a corresponding amount of unsaturated fresh air is introduced. 4. The method according to © ineßi äer>'preceding claims, in particular for the step-by-step drying of a fabric passing through several drying units , characterized in that the air flow supplied to the fabric is heated to a temperature of about 26o ° C in the first drying unit passed through, in particular by means of a gas-heated infrared heater and that the supplied to the tissue 10S81 7/0330 10 Air flow in the drying units that then pass through a lower temperature having. 5. Method according to one of the preceding claims, characterized in that the fabric is subjected to the drying air stream on a screen roller, which the fabric on a circumferential angle of about 550 ° with a predetermined tensile stress wraps around. 6. The method according to any one of the preceding claims, characterized in that the effective width of the usalaufenden screen surface automatically corresponds to the respective width of the drying fabric is adjusted during its passage. 7. The method according to claim 6, characterized in that that the effective width of the circumferential Siebfläehe unfeine such amount greater than the width of the continuous 109817/0330 Tissue is held that on both sides of the fabric edges a flow around with simultaneous Penetration of the hand areas of the tissue with sufficient space for a partial air flow that directly penetrates the screen surface. 8. The method according to any one of the preceding claims, characterized in that the circulating air flow before heating to the feed temperature on the tissue Filtering going through. 9. Device for carrying out the method according to one or more of the preceding AndrUche, characterized in that as a support and / or drive member for the fabric to be dried (44) a screen roller (34) is provided, the roll shell (35) has a free passage area of at least 85 % and preferably 90 % based on the entire circumferential area. 1098 17/0330 10. The device according to claim 9, characterized in that the roll shell (35) has a honeycomb structure made of sheet metal strelves (38) arranged in a radially upright position. 11. Device according to claim 9 or 10, characterized in that for the drying Air flow Within a housing (23) a closed flow path via a Blower (63, 64), a heater (93) and over the fabric to be dried (44) and the Interior of the screen roller (34) open at both ends is provided. 12. Device according to claim 11, characterized in that that the flow path of the drying air through the to be dried Tissue (44) radially in the for the backflow the interior of the screen roller (34) is open on both sides. 109817/0330 "I ξ> J 13. Einrichttang according to claim 11, characterized in that that the flow path of the drying air from the interior of the with Screen roller (34) provided with inflow openings on both sides radially outwards the fabric to be dried (44) runs. 14. Device according to one of claims 9 to 13 »characterized in that the flow resistance of the openwork jacket (35) of the screen roller (34) less than 1 # des Flow resistance for the drying air flow when penetrating the on the Sieve roller lying fabric (44) is. 15 · Device according to one of address 9 to 14, characterized in that for the removal of a moist partial air flow and / or for the introduction of a correspond the fresh air streams branch ducts (99 or 104, 105) with adjustable orifice elements (105 or 106, 107) are provided. 109817/0330 16. Device according to claim 15 »characterized in that within a closed housing (2jJ) an overpressure chamber (89) separated by the surface of the fabric to be dried (44) from a negative pressure chamber (91) is arranged. 17. Device according to claim 16, characterized in that the branch duct (99) is connected to the overpressure chamber (89, PIg. 2) to remove a moist partial air flow. 18. Device according to one of claims 9 to 17 »characterized in that within the Hanteis (35) of the screen roller (34) disc-shaped flanges (110,111) are slidably arranged and connected to a fixed adjusting device (122) for setting the effective width of the screen roller . 19. Device according to claim 18, characterized in that the flanges (110, 111) In the interior of the roll shell (35) through 109817/0330 -Sr- 15 Sleeves (114, II5) which can be telescoped into one another with the open ends the screen roller (34) are connected. 20. Device according to claim 18 or 19 »characterized in that the adjustment device (122) at least in the interior of a hollow shaft (47) of the Chain (123 124), the opposite of which each with one of the determining the effective width © Flanges (110, 111) are coupled. 21. Device according to one of claims 9 to 20, characterized in that for setting a tfrnschlingungswinkeIs of the continuous fabric (44) in relation to the screen roller (34l / two PUhrungswalsen (51, 52) are provided whose mutual spacing is about twice the tissue strength and their distance from the circumference of the Waizenaiaiitels (35) corresponds approximately to the simple fabric thickness. 109817/0330