US3196642A

US3196642A - Apparatus for the controlled heating of fabrics with an air/steam heating medium

Info

Publication number: US3196642A
Application number: US248332A
Authority: US
Inventors: Hugh D Terhune; Harold F Porter; James L Moore
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1962-12-31
Filing date: 1962-12-31
Publication date: 1965-07-27
Anticipated expiration: 1982-07-27
Also published as: DE1460303A1

Description

July 2 1955 H D. TERHUNE ETAL 42 APPARATUS FOR THE CONTROLLED HEATING OF FABRICS WITH AN AIR/STEAM HEATING MEDIUM Filed Dec. 51, 1962 M R OMEN MO U OMH M R M E LF DD WH MR6 AAU JHH BY v b AGENT United States Patent 3,196,642 APlARATUS FOR THE CONTROLLED HEATING 0F FABRIQS WITH AN Ant/STEAM HEATING MEDIUM Hugh 1). Terhune, Wilmington, and Harold F. Porter, Hoclressin, lDeL, and James L. Moore, Charlotte, N.C., assignors to E. I. du Pont de Nemours and Company, Wilmington, DcL, a corporation of Delaware Fiied Dec. 31, 1962, Ser. No. 248,332 6 Claims. (Cl. 68-5) This invention relates to apparatus for heating textile fabrics and for temporarily storing the heated fabric therein.

Textile fabrics, in open-width or rope form, are subjected in various commercial scouring, bleaching and similar operations to the action of .a hot fluid such as steam for the purpose of heating the fabric to accelerate or improve the action of a treating agent on the fabric. Continuous operations of this type usually involve the steps of impregnating or dampening the fabric with a treating liquor such as a bleach or scouring solution, heating the impregnated fabric with live steam and storing the heated fabric temporarily in a device such as a J-box, all such steps being carried out continuously on a continuously advancing strand of the fabric. J-box systems for carrying out such operations are described in Campbell et al. US. Patent 2,267,718 and Bell et al. US. Patent 2,858,184. Such J-box systems are generally regarded as closed systems in that they are essentially closed to the surrounding atmosphere except only for ports or openings for the entry and exit of the strand of fabric.

Closed I-box systems of the type described in the above patents are widely used and give excellent results employing live steam as the heating fluid to achieve and maintain fabric treating temperatures approaching the atmospheric boiling point of water. However, in certain operations such as the bleaching of colored yarn and certain types of cotton-synthetic fabrics, such high temperatures cannot be tolerated and fabric temperatures ranging from about 200 F. down to as low as 150 F. are often required. Uniform fabric heating to such lower temperatures is dificult to achieve and maintain in J-box systems of the above type.

Poesl US. Patent 2,346,186 proposes a modification of the J-box system of Patent 2,267,718, which modification involves a separate relatively long U-shaped heater tube through which the fabric is passed prior to its entry into the ]-box. Heating is effected by passing steam through the tube in a direction counter to the direction of travel of the fabric. It is disclosed that the temperature of the steam employed can be lowered from 212 F. to 200 F. or lower by mixing suitable amounts of air with the steam. The patent shows a device employing a steam jet to aspirate air into the steam used.

Poesls modified .l-box system functions fairly well to produce fabric temperatures down to about 205 F. However, for achieving substantially lower fabric temperatures the system is both inefficient and difficult to control. In such a system, the amount of steam required to aspirate sutficient air to produce desired relatively low fabric temperatures is often far in excess of the amount of steam;

,. ICC

delivered to the heater tube is too small to maintain the slight positive pressure in the I-box that is necessary to prevent entrance of excessive amounts of air into the system, e.g. at the fabric entrance and exit ports.

It is an object of the invention to provide an improved apparatus for continuously heating an advancing strand of fabric and temporarily storing the heated fabric. A further object is to provide an improved closed J-box system of the above type wherein controlled fabric temperatures over a wide range below the atmospheric boiling point of water can be readily and eiliciently obtained. A still further object is to provide a J-box system employing steam/ air mixtures as the fabric heating media, which system permits highly effective control of the temperature to which the fabric is heated over a range of from about F. to 205 F. Other objects will be apparent from the following description.

The objects of the invention are accomplished by a J- box system in which a substantially constant volume of air is continuously recirculated through that portion of the system wherein heating of the fabric is effected while steam is fed into the recirculating air stream in controlled amounts as required to produce the air/steam mixture necessary for a given desired fabric temperature. The accompanying drawing is a perspective view of a .T-boX system designed in accordance with the invention.

In the drawing, reference numeral 1 refers to a closed J-box of the general type described in Bell et a1. Patent 2,858,184. J-box 1, comprises a long vertical leg 2, a short vertical leg 3 with fabric exit port 5, an intermediate curved section 4, a hood section 6 and a fabric entrance leg 7 with fabric entrance port 8. Heating of the fabric is effected in hood 6 and fabric entrance leg 7, which together constitute the heating zone wherein the fabric strand 9 is contacted directly with the gaseous heating medium. Leg 2, section 4 and leg 3 of the J-box constitute the storage zone thereof wherein the heated fabric is stored temporarily to complete the action of the treating agent upon the fabric.

In hood 6 is positioned a fabric forwarding mechanism or means for continuously advancing the fabric, such as draw reel 11, indicated in the cut-away portion of the drawing, and means (not shown) for plaiting fabric strand 9 as it drops down from draw reel 11 into a compact fabric pile or mass 10 in leg 2. A suitable mechanism for use in conjunction with draw reel 11 whereby an advancing strand of fabric in ropeform is piled in a compact plaited form uniformly across the cross-section of leg 2 is shown in detail in Patent 2,858,184. Other piling and plaiting mechanism, many of which are well known, may also be employed. Thus, Terhune US. Patent 2,939,- 306 shows a plaiting mechanism for use in conjunction with a draw reel such as draw reel 11 when the .l-box is intended to handle cloth strand in open width form.

In operation, the continuous fabric strand 9 is drawn through entrance port 8 by draw reel 11. Heatiug of strand 9 is effected by its direct contact with the gaseous heating medium in leg 7 and hood 6. As strand 9 drops down from draw reel 11, it is pla-ited in leg 2 by the action of any suitable plaiting mechanism so as to form a compact fabric pile 1% from which strand 9 is pulled, by means not shown, through exit port 5.

An air/steam mixture of a composition that will produce the desired fabric temperature is passed into hood 6 by way of heating mixture entrance pipe 12 and distributor box 13, the latter being designed so as to distribute the heating mixture evenly across the Width of hood 6. The heating mixture flows through hood 6 and down fabric entrance leg 7 counter to the direction of travel of strand 9'therein. Much of the steam supplied in the heating mixture will be condensed upon the fabric as the latter is heated. A spent mixture of the air component n r d3 of the original heating mixture and residual steam that is not so condensed is exhausted from the lower portion of fabric entrance leg 7 and returned to blower 22 by way of

return pipes

14, 16, and 19. Return pipe 15, which connects with return pipe 16, provides for the return to blower 22 of any heating mixture that may have leaked past fabric pile it) into the upper part of leg 3 of the J-box. When an efficient plaiting mechanism is employed for piling fabric strand 9 in leg 2, such leakage of the heating mixture will be slight due to the sealing action of fabric pile lit; hence, return pipe 15 is not to be regarded as essential to the J-box system of the invention. However, return to blower '22 of any portion of the heating mixture which would otherwise be exhausted to the atmosphere and lost improves heating efiicien cy and is generally Worthwhile.

Return

pipes

14, 15, i6 and 19 together with heating mixture entrance pipe 12, constitute conduit means which, along with hood 6 and fabric entrance leg '7 constitute a cyclic path through which the air component of the heating mixture is continuously recycled by means of blower 22. Feeding into return pipe 19 of that cycle are steam supply pipe 1-7 and air supply pipe 20, the latter being provided with valve 27 and filter 21. Temperature sensing element 23 in pipe 12 is connected with a temperature recorder and control mechanism 24 which actua-tcs steam flow control valve 18 in pipe 17 so as to increase or decrease the flow of steam from pipe 17 into the cycle as required to maintain the temperature of the heating mixture at a desired constant value as it flows from pipe 12 into hood 6. Temperature sensing element 25 in curved section 4 of the l-box and temperature indicator or recorder 26 connected therewith provide a continuous indication of the temperature to which the fabric is being heated. If a higher or lower fabric temperature, as indicated by recorder 26, is required or desired, control mechanism 2d is adjusted so as to cause steam control valve 18 to adjust the steam supplied to the cycle in accordance with the fabric temperature desired.

The J-box system illustrated in the drawing is essentially or substantially a closed system since the only significant openings therefrom to the surrounding atmospher are fabric entry and exit ports 8 and 5, respectively. During continuous operation to heat the fabric to a given temperature,gas flow through ports 8 and is generally insignificant. However when control mechanism 24. is adjusted to change the operation from a higher to a lower temperature, less steam will be admitted via pipe 117 and air as required toprovide the new air/ steam composition corresponding to the desired lower t mperature will be drawn in via ports 8 and 5. On the other hand, when control mechanism 24 is adjusted to change the operation from a lower to a higher temperature, more steam will be admitted via pipe 17 and spent heating mixture will be vented to the atmospherevia ports 8 and '5 as required to provide the new air/steam composition correspondingto the desired higher temperature. Such entry of air into .orventing of spent heating mixture from the system via ports 8 and 5 will occur to any significant extent only-during the short periods of adjustment from one operating temperature to another. Air required for changing from a higher to a lower temperature can also be admitted via line Zil by opening valve 27. Any air admitted via line 20, which is preferably first passed through filter 2-1 to remove dust particles, can be supplied from the surrounding atmosphere or from a high pressure air system, not shown in the drawing.

The novel arrangement for supplying to the heating zone of the J-box and air/steam mixture of the composition required to produce the intended fabric temperature makes possible use of the J-box system to obtain any desired'fabric temperature over a wide range of temperatures. The system is flexible and can be adjusted at will to change the temperature to which the fabric will be heated. Moreover, fabric temperature is readily and effectively con- I trolled at the desired value under highly efiicient heating conditions. Since essentially no hot gases are exhausted to the atmosphere under fixed operating conditions, Wasteful heat losses are low and the rate of flow of the heating mixture in contact with the fabric strand in the J-box can be greatly increased, e.-g. to values that would beeconomically impractical where the spent heating mixture is simply exhausted to the atmosphere as in prior J-box systems. Such increased rates of flow of the heating mixture increases the rate of heat exchange to the fabric and faciliates uniform heating of the fabric.

It will be apparent from the foregoing description that the fabric heating and storage system of the invention comprises the combination of a closed fabric heating and storage apparatus such as a closed J-box with a piping assembly that establishes a confined cyclic flow path for an air/ steam heating medium, which path includes as an integral part thereof the heating zone of the J box wherein a continuously advancing strand of the fabric is heated by direct'oontact with the .air/ steam heating medium. The cyclic flow path is provided with means such as a blower for maintaining a continuous rapid How of the heating medium therein whereby the spent heating medium withdrawn from the heating zone of the J-box is continuously recycled to said heating zone, and also with means for injecting steam and air (when required) into the recycle stream of the heating medium in'such amounts as are required to maintain the heating medium entering the heating Zone of the J-box at a desired constant composition.

It will be obvious that various modifications and adaptations of the preferred embodiment of the invention illustrated by the drawing may be made without departing from the scope and spirit of the invention. Thus, entrance leg 7 of the I-box shown in the drawing, which in reality is but an extension of the hood portion of the ]-box, may be arranged horizontally or in any other desired position, orit may be dispensed with enti ely if desired but at a sacrifice in heating efficiency. A separate heating tube such as that described in Poesl Patent 2,346,186 may be employed whether in addition to or in place of fabric entrance leg '7, provided such separate heating tube is included as an integral part of the cyclic flow path for the air/steam heating medium. Draw reel 11 of the drawing may be replaced by a plurality of draw reels or by any other suitable mechanism for continuously drawing the fabric strand into hood 6. As indicated previously, any suitable plaiting or piling means Y 'may be employed for piling the heated strand evenly across the cross-section of the storage portion of the Lbox. Furthermore, the direction of flow of the air/ steam heating medium through the hood of the J-box may be reversed so that the heating medium and the fabric will travel in the same direction. In such modification, which is distinctly not preferred, the recycled and reconstituted air/steam heating medium would enter the lower portion of fabric entrance leg '7 while the spent heating medium would be withdrawn from hood 6 of the J-box.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined a follows:

ll. Apparatus for continuously heating textile fabric preimpregnated with a treating liquid and for temporarily storing the heated fabric therein, said apparatus comprising a substantially closed I-box and means to continuously advance a strand of fabric therethrough, said J-box including a fabric heating zone having a fabric entrance port and a fabric storage zone having a fabric exit port, means to supply an'air/ steam heating medium directly to said heating zone and the fabric advancing therethrough, said fabric storage zone being utilized to temporarily store said heated fabric in a compact mass, conduit means and circulating means for said heating medium, said conduit means extending from said circulating means to said heating zone and from said heating zone to said circulating means, and means for continuously supplying a controlled amount of steam to said heating medium in said conduit means.

2. Apparatus for continuously heating textile fabric preimpregnated with a treating liquid and for temporarily storing the heated fabric therein, said apparatus comprising a substantially closed I-box and means to continuously advance a strand of fabric therethrough, said J-box including a fabric heating zone having a fabric entrance port and a fabric storage zone having a fabric exit port, means to supply an air/ steam heating medium directly to said heating zone and the fabric advancing therethrough, said fabric storage zone being utilized to temporarily store said heated fabric in a compact mass, conduit means and circulating means for said heating medium, said conduit means extending from said circulating means to said heating zone and from both said heating zone and said storage zone to said circulating means, and means for continuously supplying a controlled amount of steam to said heating medium in said conduit means.

3. Apparatus for continuously heating textile fabric preimpregnated with a treating liquid and for temporarily storing the heated fabric therein, said apparatus comprising a substantially closed J-box and means to continuously advance a strand of fabric therethrough, said J-box including a fabric heating zone having a fabric entrance zone and a fabric storage zone having a fabric exit port, means to supply an air/ steam heating medium directly to said heating zone and the fabric advancing therethrough, said fabric storage zone being utilized to temporarily store said heated fabric in a compact mass,

conduit means and circulating means for said heating medium, said conduit means extending from said circulating means to said heating zone and from said fabric entrance zone to said circulating means, and means for continuously supplying a controlled amount of steam to said heating medium in said conduit means.

4. Apparatus according to claim 1 wherein the circulating means is a blower.

5. Apparatus according to claim 1 wherein the means to supply the controlled amount of steam includes a valve actuated by a temperature sensing means positioned in the conduit means extending from the circulating means to the heating zone.

6. Apparatus according to claim 1 Which includes means for supplying air to said heating medium in said conduit means.

References Cited by the Examiner UNITED STATES PATENTS 955,001 4/10 Schilde 68--6 2,157,975 5/39 Wilson 685.3 2,008,230 7/35 Spooner 68-5.4 2,346,186 4/44 Poesl 68-6 2,858,184 10/58 Bell 68-178 X 3,027,740 4/62 Sonnino 68-5.5 3,067,602 12/62 Brunt 685.5

IRVING BUNEVICH, Primary Examiner.

WALTER A. SCHEEL, Examiner.

Claims

1. APPARATUS FOR CONTINUOUSLY HEATING TEXTILE FABRIC PREIMPREGNATED WITH A TREATING LIQUID AND FOR TEMPORARILY STORING THE HEATED FABRIC THEREIN, SAID APPARATUS COMPRISING A SUBSTANTIALLY CLOSED J-BOX AND MEANS TO CONTINUOUSLY ADVANCE A STRAND OF FABRIC THERETHROUGH, SAID J-BOX INCLUDING A FABRIC HEATING ZONE HAVING A FABRIC ENTRANCE PORT AND A FABRIC STORAGE ZONE HAVING A FABRIC EXIT PORT, MEANS TO SUPPLY AN AIR-STEAM HEATING MEDIUM DIRECTLY TO SAID HEATING ZONE AND THE FABRIC ADVANCING THERETHROUGH, SAID FABRIC STORAGE ZONE BEING UTILIZED TO TEMPORARILY STORE SAID HEATED FABRIC IN A COMPACT MASS, CONDUIT MEANS AND CIRCULATING MEANS FOR SAID HEATING MEDIUM, SAID CONDUIT MEANS EXTENDING FROM SAID CIRCULATING MEANS TO SAID HEATING ZONE AND FROM SAID HEATING