US3665734A

US3665734A - Apparatus for finishing fibrous material

Info

Publication number: US3665734A
Application number: US871361A
Authority: US
Inventors: Paul Hauser; Walter Pfister; Hans Ulrich Stucki; Heinz Teuwen; Heinrich Fuhring; Johannes Helmut Sieber
Original assignee: Bohler & Weber KG Maschinenfab
Current assignee: Boehler & Weber Kg-Maschinenfabrik-Augsburg; Bohler & Weber KG Maschinenfab
Priority date: 1964-06-05
Filing date: 1969-09-15
Publication date: 1972-05-30
Anticipated expiration: 1989-05-30
Also published as: ES313753A1; GB1109686A; DE1469263A1; NL6507107A; BE664964A; FR1444332A; DE1469263B2

Abstract

Fibrous material in web or filament form, to be dyed or otherwise chemically treated, is successively passed through a plurality of chambers including a treatment chamber in which it is subjected to the spray of a fluid, a drying chamber which may be subdivided into several compartments, and an intervening reaction chamber in which a controlled amount of moisture is added and which may be preceded by a preconditioning chamber provided with temperature-control means. Air is forcibly circulated, with the aid of a primary blower, from a location near the inlet end of the treatment chamber to a point of the drying chamber remote from the treatment chamber whereby this air passes through the interconnected chambers in counter-current to the treated material. Each chamber may also be provided with an individual secondary air path containing a blower for generating a flow which passes only through that chamber in counterflow to the treated material.

Description

United States Patent Hauser et al.

APPARATUS FOR FINISHING FIBROUS MATERIAL Assignee: Bohler & Weber KG-Maschineniabrik- Augsburg, Hamburg, Germany Filed: Sept. 15, 1969 Appl. No.: 871,361

Related US. Application Data Division of Ser. No. 462,167, June 4, 1965, abandoned.

Foreign Application Priority Data June 5, 1964 Switzerland ..7363/64 U.S. Cl. 1.68/18- C, 68/18 F, 68/191,

68/20 Int. Cl. ..B05c 3/132, BOSc 9/10, BOSc 9/12 Field of Search ..68/l8 R, l8 C, 18 F, 20, 3 R,

68/5 D,5 E, 3 SS, 19.1, 19

References Cited UNITED STATES PATENTS Gruber-Rehenburg et a]. ..68/ l 8 X I I l l l 51 May 30, 1972 2,199,233 4/1940 Williams ..68/2O X 2,571,494 10/1951 Spooner ..68/20 X FOREIGN PATENTS OR APPLICATIONS 1,059,530 11/1953 France ..68/l8 Primary Examiner-William l. Price Att0rneyl(arl F. Ross [57] ABSTRACT Fibrous material in web or filament form, to be dyed or otherwise chemically treated, is successively passed through a plurality of chambers including a treatment chamber in which it is subjected to the spray of a fluid, a drying chamber which may be subdivided into several compartments, and an intervening reaction chamber in which a controlled amount of moisture is added and which may be preceded by a preconditioning chamber provided with temperature-control means. Air is forcibly circulated, with the aid of a primary blower, from a location near the inlet end of the treatment chamber to a point of the drying chamber remote from the treatment chamber whereby this air passes through the interconnected chambers in counter-current to the treated material. Each chamber may also be provided with an individual secondary air path containing a blower for generating a flow which passes only through that chamber in counterflow to the treated material.

18 Claims, 5 Drawing Figures HEA r52 l Moan/e5 ass/5oz 8 2 zswcr/mrzo-meaalwawiry Patented May 30, 1972 2 Sheets-sheet 2 51 has/a r51? cowaawssp 71 s r24 wag Paul Hauser d fer Pfisfer Hans U- S i Heinz Teuwen Heinrich Furing Johannes H. Sieber INVENTORS.

By To 5 flesiem APPARATUS FOR FINISHING FIBROUS MATERIAL This application is a Division of Ser. No. 462,167, filed June 4, 1965 and now abandoned.

Until now it was usual to finish especially woven and knitted textiles and bands of bonded fibers in aqueous media. These complicated working methods are all identified by high cost of apparatus and operation. So,-for instance, large quantities of water and high drying energies are usually required. Shrinkage is often observed which after finishing must be compensated for. Substantial, costly waste-water problems arise since superfluous unused chemicals have to be separated from the waste water. With some materials, as for instance cellulose acetate, very often in aqueous finishing an uneven fabric appearance results. In dyeing the loss of dyestuff is relatively high. Finally, the finishing processes often have to be performed one after the other and a single-stage continuous finishing is not possible. The complete finishing up to the saleable textile material is therefore very time-consuming. The result of this is that a relatively large amount of stock has to be carried in order to be able to give short-time delivery.

It is the aim of the invention to remove the above-mentioned disadvantages by a new fabric-treating system.

An apparatus according to the invention, comprises means for the saturation of the goods with a liquid, as for instance in a padding machine, in conjunction with transport arrangements consisting of rollers or the like for the guiding a web of textile material and a recovery section for volatile condensable substances, the two sections being interconnected by a forced-circulation path including blower means, a condensor and, if necessary, an air heater.

With conventional drying, strips and webs of solvent-wetted material would be guided within a housing over several rollers in an up-and-down fashion by means of loops. Via a recovery section air is blown in such a system in a closed circuit from above into the housing and drawn away underneath. This arrangement, however, does not dry textiles evenly and is, therefore, unsuited for finishing, since an uneven deposition of chemicals would result. Moreover, this continuous heating and cooling of the total required air quantity is very expensive with its high rate of energy consumption.

The apparatus according to the invention aims at avoiding the above-mentioned disadvantages and achieves an economical drying process with the least expense. At the same time in the whole drying zone a favorable and even concentration gradient between the textile material and the surrounding air for a uniform deposition of the finishing chemicals is achieved.

The treatment chamber of the apparatus according to the invention is followed by a drying chamber whose walls surround a section of traveling material moving vertically, the recovery section being connected to this drying chamber by the aforementioned path forming a closed circuit with a suction side in the area of the entry of the material into the treatment chamber and with a high pressure side in the area of the exit of the material from the drying chamber. In a particularly advantageous embodiment of the invention a number of drying chambers are provided which are joined with their vertical sides through which the web of material travels in alternating directions with the aid of reversing rollers or the like. Thus, the drying air flows over the material in a counter-current whereby a progressive enrichment of the air with solvent vapors is achieved with a roughly constant concentration gradient.

In a particularly practical version the chambers are formed as adjoining compartments within a closed housing subdivided by vertical partitions.

In order to increase the economy of drying and recovery, we prefer to supplement the recovery section with its primary air circuit through the cascaded treatment and drying chambers by mounting a separate blower or fan, followed by an air heater, in a further, secondary air circuit individual to each of these chambers. In particular it is desirable that the air heater be connected to banks of jets which are on both sides of the traveling material with the jets directed against the material. Thus it is no longer necessary to circulate large quantities of air with low vapor concentrations through the recovery sections. The economy of condensation is increased, since the vapor concentration of the air which reaches the recovery section via the main air circuit is considerably stepped up, because of the rapid continuous circulation of the air quantity which is contained in each individual chamber while it is being heated and enriched with solvent vapor. v

These and further features are illustrated by way of example and schematically in the accompanying drawing in which FIG. 1 is, a schematic side view of the apparatus for the finishing of material in web form in solvent according to the invention;

FIG. 2 is, a schematic side view of a reaction chamber which is preceded by a dyeingmachine;

FIGS. 3 and 4 show an arrangement for the preconditioning of a continuous length of fabric;

FIG. 5 is a diagram of a cleaning and finishing plant.

With the arrangement according to FIG. I the cloth 1 travels through the treating means 2 which consists of the chassis or liquid-containing trough 3 and the squeezing rollers 4, and then enters the treatment chamber 5. Its direction is changed by the rollers 6 and then it passes approximately in a straight line, yet in alternating directions, through a series of

drying chambers

7, 8 and 9 which are situated beside chamber 5. The chambers are formed inside the closed housing 11 by dividing walls or partitions 10.

For the recovery of the solvent in the primary air circuit the fan 12 and, on its downstream side, the cooler 13 are arranged. The suction side of the fan 12 is in turn connected via a duct 15 with an intake port 15a to the entrance section of chamber 5. The cooler 13 is connected via a duct 16 with the exit of chamber 8. In this way a recovery circuit is formed in which the drying air passes successively, counter-current to the traveling material, through

chambers

8, 7 and 5. If necessary, beyond the cooler 13 a heater 14 may be provided which is only indicated in dotted lines in the drawing.

The

individual chambers

5, 7 and 8 can, as may be seen from the left-hand section of FIG. 1, be provided with a further fan 17' and an air heater 18 on its downstream side. The fan is connected with its suction side via a duct 19 to one end of the chamber, so that a secondary air stream travels through the individual chamber in a closed circuit. The heater 18.may be situated on the suction or on the high pressure side of the fan 17. Preferentially the heater 18 is disposed ahead of two sets of air jets 21, lying on both sides of the path of fabric 1, through which the material may be treated from both sides with hot air via a conduit 20 with discharge ports 20a, 20b. Such an arrangement can be provided in each one of the chambers. For the sake of simplicity, however, this arrangement is shown in FIG. 1 only for chamber 5. By means of the secondary air circuit the air in the individual chambers is very quickly circulated and thereby constantly warmed and enriched with solvent gases. The air which is drawn in by fan 12 and which is then pressed into cooler 13 has, therefore, a considerably higher solvent-vapor concentration than it would have without the presence of such a secondary air circuit.

In order to maintain a certain water recovery from the material, a

valve

23 or 23 of an arrangement which injects steam or water into the circuit is controlled by the hygrometer 22 in the duct 19 which measures the humidity of the air leaving the chamber. The operation of the valve 23 or 23' by means of the hygrometer 22 takes place by a well-known electrical system and is therefore indicated only by the dotted line 24. The injection of fine water droplets into the air circuit takes place advantageously before the entry of the air into the air heater. The injection of steam can also be performed beyond the heater. In this way a certain relative humidity in the individual chambers may be created and constantly maintained. The water recovery from the material leaving the drying chambers may alternatively be controlled by a recoverymeasuring device 55 which, by well-known means, is connected to the steam or

water spray valves

23 or 23. An air inlet is shown at 56.

Depending on requirements, several of such drying chambers may be mounted side by side, so that the traveling materia] has to pass one after the other. In this arrangement, chambers which are disposed in series may be connected to a

recovery section

12, 13. There can also be

several recovery sections

12, 13 assigned to a smaller group of chambers. Through a further chamber 9, following the chambers which serve for the drying and recovery, fresh air may be drawn with the aid of a fan 26 which is mounted on an activated-carbon recovery stage 25. In a preferred embodiment final compartment 9 of the drying stage has a duct 27 forming an extraction circuit (in direction of the arrow) in order to recover the last traces of solvent. The

individual ducts

20, 27 may be provided with branch lines 28 which can be closed or opened and which lead into the atmosphere or to an activated-carbon recovery plant. it is further advantageous to have a suction duct 29 connected to the housing of the treating means which also leads to an activated-carbon recovery plant.

In order to create particularly favorable conditions for the reaction of the treated material with the treatment agent even after it has left the treating means, a separate reaction chamber according to FIG. 2 is provided in which certain accelerating reaction conditions may be created and in which the material is transported without any contact with the surroundings over a long stretch. The length of this stretch depends on the kind and condition of the material, on the degree of pre-drying by extraction rollers 30 corresponding to rollers 4 of FIG. 1, and on the speed of movement of the material through the reaction zone. According to the invention, the reaction is controlled by the creation of certain temperatures and humidities, for instance by the introduction of water or solvent vapor and also by the introduction of certain chemicals in their vapor phase. The reaction chamber is preferentially arranged in such a way that the material travels through it vertically, since then the dyeing machine may be mounted directly underneath or above the chamber without the use of any direction-changing rollers.

According to FIG. 2 the material leaves the dyeing machine and enters the reaction chamber 31 which is situated immediately above or underneath it, and the material is moved into the following drying zone (corresponding to chamber 7 of FIG. 1) only after, at the bottom end of chamber 31 its direction is changed by a deflecting roller 32 and a further pair of rollers 33. To the chamber 31 is connected a separate recovery section which consists of fan 34, cooler 35 and heater 36, so that air may circulate, according to

arrows

37 and 38, through chamber 31. For the establishment of a certain relative humidity in the chamber, the hygrometer 39 controls two valves 40 and 41 which are respectively connected to a water-spray arrangement or a steam inlet. For the adjustment and constant maintenance of a certain temperature and solvent-vapor concentration in the reaction chamber 31, a regulating means 42 for the operation of the air heater or a regulating means 43 for the cooling water supplied to the cooler 35 are controlled by a device 44 in the air leaving the chamber, for instance a thermostat. The vapor concentration in the chamber may also be controlled by two thermostats 45- and 46 which measure the temperature drop across the cooler 35. For the purpose of the introduction of further chemicals another pipe 47 with valves may be connected to the circuit.

The various means described enable an increase in the speed of reaction by the creation of favorable reaction conditions for the absorption of the chemical by the swelling fibers through temperature control, through the maintenance of certain relative vapor concentrations of oleophilic and hydrophilic media and by the addition of condensation accelerators in vapor form. The injection of steam or vapors of volatile chemicals increases the heat content of the drying air and the azeotropic drying conditions speed up the drying process itself. Finally, the danger of condensation of the additive on the walls of the chamber may be avoided by the introduction of the steam or vapors into the hot air stream coming from the air heater ofthe air circuit.

The effective length of the reaction zone within chamber 31 may, within certain limits, be altered by the adjustment of the deflecting rollers 32 in the direction of arrow 48. In order to further increase the absorptive capacity of the fibers for certain chemicals, the invention provides for a preconditioning zone through which the material has to travel prior to the entrance into the reaction chamber or into the treating means and in which, according to fiber-content, it is treated with solvent or water vapor. By means of this primary swelling and warming-up of the fibrous material, prior to its passage through the treating means or dyeing machine, thesubsequent absorption of the chemicals is further accelerated and the reaction time is considerably reduced. For this purpose in FIG. 3a preconditioning chamber 49 is arranged in front of the squeeze rollers 30, forming part of a padding or impregnating unit, in which the material is passed through an atmosphere enriched with vapor (as schematically indicated at 53) and in which its direction is changed several times in the form of loops by deflecting rollers 50. in its lower region the chamber is filled with a liquid which is evaporated by means of the heating coil 51. The entry and exit of the material may be protected from vapor loss through cooling coils 52.

FIG. 4 shows a modified arrangement including a preconditioning chamber 49' with deflecting rollers 50, heating means 51' and cooling means 52' interposed between rollers 30 and treatment chamber 31.

The speed of the drive for the material may be regulated in dependence upon the solvent vapor concentration in one of the chambers, or in dependence upon the solvent content of the material itself. In the example of FIG. 1 a device 54 for measuring solvent-vapor concentration is provided in the outlet of the air from fresh-air chamber 9 which, in turn, can adjust by known means the speed of the transport means.

Since the material cannot be transported indefinitely in a direct line without contact with its surroundings for the purpose of undisturbed reaction with the applied chemicals, the disturbing effect of the direction-changing rollers may be avoided by temperature-conditioning of the rollers through suitable cooling and/or heating means.

if elevated temperatures are required for the reaction of the applied chemicals with the material, the possibility exists to provide a heating arrangement, for instance infrared heaters, for the passing materials in a chamber which is attached to the drying chamber beyond the fresh-air zone. FIG. 5 shows schematically a washing and finishing machine according to the invention. Here the individual circuits are represented by lines in which an arrow indicates the direction of the flowing medium. The necessary valves for the opening and closing of the individual branch lines are indicated schematically by crosses. Their adjustment, which is required to make and break the various connections, is ascertainable from the function of the individual components. I

Pumps 61 and 62 may continuously draw solvent from the

containers

57 and 58 and return same in a circuit (see direction of arrows) to these containers. This can take place directly (with valve 66 opened,

valve

64 and 65 being closed) or by means of the filters 67 and 68 (valve 66 closed,

valves

64 and 65 opened) so that the solvent is freed from solid impurities at the same time. In the same example the solvent is sprayed through jets 63 onto the material 1 from both sides and then passed into the

containers

57 and 58, the solvent flowing counter-current to the direction of movement of the material from container 58 into container 57. For the complete regeneration of the solvent fluid may be drained to still 7 from filters 67 and 68 through the opening of valve 69. It then enters the condenser 71 during the evaporation and is condensed there. .The liquid collects in water separator 72 from where it flows to the storage tank 73 for the clean solvent. From storage tank 73 the solvent may be directly passed to the jets 75 via valve 74. The latter jets rinse the web 1, coming from container 58, once more with clean solvent. Via valve 76 the solvent from the storage tank 73 may also be introduced into the pump circuit. The

pumps

61 and 72 may be connected via

pipes

93 and 94 with the still 70, so that the solvent which has originally been taken out of the storage tank 73 and which is used in the pump circuit may be recycled for regeneration.

The material 1 leaving the housing 60 may be directed via the squeezing rollers 77 through a pre-drying zone 78 before it enters the actual padding machine 79. In some instances it is also possible to forego the use of this pre-drying zone 78 which therefore has been indicated only in dotted lines.

The padding machine 79 for the treatment with finishing chemicals may, in similar fashion, be connected with a pump circuit including a filter and a still, as previously described. For the sake of clarity this is indicated in FIG. 5 only by means of the two

pipeline branches

80 and 81 in which advantageously a strainer 82 is fitted into the suction side of the pump. A storage tank 83, filled with a concentrate of the chemical to be deposited on the material 1, and a further storage tank 84, filled with a working-strength solution of the treating liquor, are connected via pipe 85 to the vessel 86 of the padding machine 79. A closing means 87 for the container 83, for instance a valve, is controlled by a device 88 which measures the specific gravity of the liquid in container 86, so that with falling concentration of the dissolved material in the treating liquid valve 87 opens and closes again. In a similar manner a valve 89 is provided in the outlet of tank 84 which is controlled by a solvent-level gauge in container 86, for instance a float switch, so that with rising or falling level the outlet from tank 84 is closed or opened. The two

outlets

87 and 89 are electrically connected in such a way that the valve 89 of the working-concentration tank 84 may be opened only when the concentration of the chemical in the padding machine is correct and when the valve 87 of the concentrate tank 83 is closed. The apparatus required for such measurement and control is well known and not described in detail. The control functions are, therefore, shown only schematically by means of the dotted lines 91 and 92.

The solvent which the material brings with it from the previous scouring stage unavoidably causes a dilution of the finishing liquid in the treating means as well as an increase in the liquid quantity in the container 86 of the treating means 79.

By means of the regulating method described above this danger is, however, eliminated. The described measures are equally valid when a two-roller dyeing machine is used in which the treatment liquid is contained between the two rollers.

oleophilic solvent it is advantageous to provide on the suction side of the pump an addition funnel or the like, so that the emulsification of the additive takes place within the pump. By means of an ultrasonic vibrator, an excellent emulsification or dispersion of solvent-insoluble materials may be achieved in the container which holds the treatment liquor. By such ultrasonic vibrators, which are mounted in the chambers, the passing material is agitated and the reaction of the chemical on the material is improved.

As dyestufis, various classes of conventional texn'le dyes may be used, particularly those of the classes of nitro, azo, and anthrachinon dyestuffs. In the first instance, so-called fat-soluble dyestuffs are to be considered which have no acid or saltforming groups, are often readily soluble in the organic carrier liquid and give full, deep colors. Also dyestuffs which without being fat-soluble contain oleophilic components, for instance higher molecular-weight hydrocarbon residues, even if they contain acid or salt-forming groups as long as these are not used in their usual form as water-soluble alkali salts, are suitable.

EXAMPLE 1 For the dyeing of a web of cloth of cellulose acetate, the dyestufi' represented by the formula below is dissolved in the ratio of l 100 in carbon'tetrachloride:

In order to be able to emulsify hydrophilic substances in the gr m EXAMPLE 2 For the dyeing of cloth made of cellulose-2,5-acetate an azo-dyestufi of the following formula is dissolved in the ratio l in trichlorethylene:

The solution is used as described in Example 1 and aclear,

strong yellow color is achieved.

EXAMPLE 3 For the dyeing of cloth made of cellulose-tri-acetate, an azo-dyestuff of the following formula is dissolved in the ratio of l in trichlorethylene. The solution is clarified and then entered into the treatment means. The cloth is passed through the bath at 8 meters per minute under the conditions mentioned in Example 1.

A strong yellow color is obtained. A similar effect may be obtained when using perchlorethylene as solvent with a fabric consisting of cellulose-2,5-acetate. This yellow dyeing can also be carried out when the described method is applied to a cloth of regenerated cellulose (viscose).

([1 C1 C00 CzoHz =N\ N=N H-C 0 g We claim: 1. Apparatus for chemically treating fibrous material, comprising:

a substantially closed housing forming a plurality of adjoining chambers for material to be treated, including a treatment chamber with an inlet for said material followed by a drying chamber with an outlet for said material;

guide means in said housing for successively directing a length of said material through said chambers;

supply means in said treatment chamber for applying a treatment fluid to said material;

conduit means forming a forced-circulation path for solvent vapors from said treatment chamber, said path originating at a location of said treatment chamber proximal to said inlet and terminating at a location of said drying chamber remote from said treatment chamber; and

blower means in said path for generating an air flow in said conduit means traversing said drying and treatment chambers in counter-current to said material.

2. Apparatus as defined in claim 1 wherein said drying chamber is subdivided into a first compartment close to said treatment chamber and at least one further compartment beyond said first compartment, said path tenninating at said further compartment.

3. Apparatus as defined in claim 2 wherein said drying chamber includes a final compartment beyond said further compartment, said final compartment being provided with additional blower means for recirculating air in a secondary path from a discharge side to an entrance side thereof.

4. Apparatus as defined in claim 3 wherein said guide means directs said material vertically downwardly through said final compartment, said secondary path starting at the bottom and ending at the top of said final compartment.

5. Apparatus as defined in claim 3, further including solvent-recovery means in said secondary path.

6. Apparatus as defined in claim 1, further comprising cooling means disposed in said path downstream of said blower means.

7. Apparatus as defined in claim 1 wherein said treatment chamber is provided with further conduit means forming a secondary air path from a point of said treatment chamber near said inlet to a point thereof proximal to said drying chamber, said supply means being disposed between said points, said secondary air path including additional blower means for circulating vapor-laden air therethrough.

8. Apparatus as defined in claim 7 wherein said further conduit means is provided with hygroscopically controlled means for admitting moisture into said secondary air path.

9. Apparatus as defined in claim 7 wherein said secondary air path further includes heating means downstream of said additional blower means.

10. Apparatus as defined in claim 7 wherein said supply means comprises two sets of jets on opposite sides of the line of travel of said material through said treatment chamber, said forced-circulation path and said secondary air path having intake ports located in said treatment chamber at said opposite sides ahead of said sets of jets.

11. Apparatus as defined in claim 10 wherein said secondary air path has discharge ports entering said treatment chamber at said opposite sides beyond said sets of jets.

12. Apparatus as defined in claim 1 wherein said chambers include a reaction chamber between said treatment and drying chambers and a source of moisture for said reaction chamber.

13. Apparatus as defined in claim 12 wherein said source includes an air duct communicating with said reaction chamber at an entrance side and an exit side for said material and further blower means in said air duct for circulating air therethrough from said entrance side to said exit side, said duct having an inlet connection for aqueous fluid.

14. Apparatus as defined in claim 13, further comprising hygroscopically controlled means in said duct for regulating the moisture content of said reaction chamber.

15. Apparatus as defined in claim 13 wherein said chambers include a preconditioning chamber, immediately ahead of said reaction chamber, provided with temperature-control means.

16. Apparatus as defined in claim 15 wherein said guide means includes a pair of squeeze rollers engaging said material at an end of said preconditioning chamber.

17. Apparatus as defined in claim 1 wherein said chambers extend vertically in said housing, said guide means comprising a top deflector and a bottom deflector in each chamber engaging said material for vertical motion in otherwise unsupported manner between said deflectors.

18. Apparatus as defined in claim 17 wherein at least one of said chambers is provided with an individual duct, communicating therewith at the top and the bottom, and with additional blower means in said duct for circulating air therethrough and through the chamber in counterfiow to said material.

Claims

2. Apparatus as defined in claim 1 wherein said drying chamber is subdivided into a first compartment close to said treatment chamber and at least one further compartment beyond said first compartment, said path terminating at said further compartment.
3. Apparatus as defined in claim 2 wherein said drying chamber includes a final compartment beyond said further compartment, said final compartment being provided with additional blower means for recirculating air in a secondary path from a discharge side to an entrance side thereof.
4. Apparatus as defined in claim 3 wherein said guide means directs said material vertically downwardly through said final compartment, said secondary path starting at the bottom and ending at the top of said final compartment.
5. Apparatus as defined in claim 3, further including solvent-recovery means in said secondary path.
6. Apparatus as defined in claim 1, further comprising cooling means disposed in said path downstream of said blower means.
7. Apparatus as defined in claim 1 wherein said treatment chamber is provided with further conduit means forming a secondary air path from a point of said treatment chamber near said inlet to a point thereof proximal to said drying chamber, said supply means being disposed between said points, said secondary air path including additional blower means for circulating vapor-laden air therethrough.
8. Apparatus as defined in claim 7 wherein said further conduit means is provided with hygroscopically controlled means for admitting moisture into said secondary air path.
9. Apparatus as defined in claim 7 wherein said secondary air path further includes heating means downstream of said additional blower means.
10. Apparatus as defined in claim 7 wherein said supply means comprises two sets of jets on opposite sides of the line of travel of said material through said treatment chamber, said forced-circulation path and said secondary air path having intake ports located in said treatment chamber at said opposite sides ahead of said sets of jets.
11. Apparatus as defined in claim 10 wherein said secondary air path has discharge ports entering said treatment chamber at said opposite sides beyond said sets of jets.
12. Apparatus as defined in claim 1 wherein said chambers include a reaction chamber between said treatment and drying chambers and a source of moisture for said reaction chamber.
13. Apparatus as defined in claim 12 wherein said source includes an air duct communiCating with said reaction chamber at an entrance side and an exit side for said material and further blower means in said air duct for circulating air therethrough from said entrance side to said exit side, said duct having an inlet connection for aqueous fluid.
14. Apparatus as defined in claim 13, further comprising hygroscopically controlled means in said duct for regulating the moisture content of said reaction chamber.
15. Apparatus as defined in claim 13 wherein said chambers include a preconditioning chamber, immediately ahead of said reaction chamber, provided with temperature-control means.
16. Apparatus as defined in claim 15 wherein said guide means includes a pair of squeeze rollers engaging said material at an end of said preconditioning chamber.
17. Apparatus as defined in claim 1 wherein said chambers extend vertically in said housing, said guide means comprising a top deflector and a bottom deflector in each chamber engaging said material for vertical motion in otherwise unsupported manner between said deflectors.
18. Apparatus as defined in claim 17 wherein at least one of said chambers is provided with an individual duct, communicating therewith at the top and the bottom, and with additional blower means in said duct for circulating air therethrough and through the chamber in counterflow to said material.