US3353381A

US3353381A - High velocity tow washing cascade

Info

Publication number: US3353381A
Application number: US509749A
Authority: US
Inventors: Jr Ernest Austin Taylor
Original assignee: Monsanto Co
Current assignee: Monsanto Co
Priority date: 1965-11-26
Filing date: 1965-11-26
Publication date: 1967-11-21
Anticipated expiration: 1984-11-21

Description

Nov. 21, 1967 E. A. TAYLOR, JR 3 3 1 -HIGH VELOCITY row WASHING CASCADE 5 Sheets-Sheet 1 Filed Nov. 26, 1965 FIG. 3. FIG.2.

vINVEN'I'OR. ERNEST A TAYLOR,JR.

f1 52 50 V v 46 BY PCZAJQM ATTORNEY NOV-I 1967 E. A." TAYLOR, JR 3,353,331

---------- I' lY TOW WASHING CASCADE Filed Nov. 26, 1965 s sheets-sheet 2 INVENTOR. v

ERNEST A. TA YLOR,JR.

\ v BY M ATTORNEY E. A. TAYLOR, JR

HIGH VELOCITY TOW WASHING CASCADE Filed Nov. 26, 1965 3 Sheets-Sheet :5

L nk/Avg FV V W Q s i I iizz m'ma 76 H r 69 128 \1 I30 134 mi Elm k13B 134 a I1 I42 I46 [24* Him ail-Jim I22 L... +F J WASH WATER INLET I26 FIG. 8.

' DRAIN E: :EI n

2 I56 I56 WASH WATER I64 OUTLET TO DRAIN OR SOLVENT RECOVERY I58 I62 U I I IL Y INVENTOR.

WASH WATER INLET BY ERNEST A. TAYLOR, JR.

United States Patent 3,353,381 HIGH VELOCITY TOW WASHING CASCADE Ernest Austin Taylor, Jr., Decatur, Ala., assignor to Monsanto Company, St. Louis, Mo., a corporation of Delaware Filed Nov. 26, 1965, Ser. No. 509,749 26 Claims. (Cl. 68184) ABSTRACT OF THE DISCLOSURE This invention provides an apparatus for continuously Washing a moving tow of synthetic fibers, the tow being spread into ribbon form. The apparatus is provided with an elongated chamber through which the tow and water are passed. The chamber is provided with a plurality of curved deflecting surfaces which force the water to sweep back and forth through the tow from one side of the chamber to the other.

This invention relates to an apparatus for washing synthetic fibers and more particularly relates to an apparatus for washing synthetic fibers in which washing fluid is directed substantially perpendicularly to the plane in which the synthetic fibers move while at the same time, the washing fluid is directed both countercurrent and with the direction of filament flow.

In the wet spinning process of making synthetic fibers, a dope which consists of a polymer or copolymer and a solvent is extruded through spinnerettes into a coagulating bath. Filaments are formed as the coagulating fluid comes in contact with the extruded dope. These are gathered into a group, the aggregation of which comprises the tow. In order to produce a filamentary tow having good textile processing characteristics, the residual solvent existing therein must be removed. This operation is presently performed by passing the tow along what is known as a cascade in which the tow is drawn upward along a countercurrent flow of washing fluid, generally water.

Difiiculty has been experienced in removing the solvent from the tow as it travels along the cascade because it carries therewith an amount of washing fluid which forms a boundary layer around each filament. This boundary layer impedes the rinsing process for the wash fluid cannot eflectively circulate through the tow and contact the fibers due to the aflinity of the fibers for the fluid.

Heretofore attempts have been made to remove this boundary layer by utilizing a stripping process performed either by sharply bending the tow or by nipping it. Since the tow is generally drawn up the cascade along a straight path under tension, it cannot be bent with any effectivenes. Stripper bars and rollers have been employed to squeeze the tow as it passes along the cascade and hence attempt to remove the boundary layer therefrom. This method is often times ineffective unless great pressure is utilized especially where tows of a large denier are being washed. The disadvantages of applying great pressure to a synthetic filament still partly imbued with solvent are self-evident. Furthermore, an increase in pressure causes an increase in friction between the outer fibers and the stripping means resulting in breakage and further damage.

According to the present invention it has been found that these difficulties may be overcome by utilizing an elongated washing compartment having a plurality of baflles extending thereacross. The washing compartment is formed by a pair of troughs removably secured or hinged together, each including deflectors extending across their bottom. The deflectors on the troughs are arranged to form the compartment baflles and result in a tortuous "ice path for a flow of washing fluid, such as water, through the compartment. The deflectors are arranged to alternately direct the fluid toward and through the tow from above at substantially a perpendicular angle and then at the tow from below at substantially a perpendicular angle as it flows thereby.

Fluid flow commences at an inlet located intermediate the ends of the trough and is divided and directed outwardly in opposite directions. In this manner the tow passing through the washing device, which is the subject of this invention, is subjected partly to a countercurrent fluid flow and partly to a flow in the direction in which the tow is moving. At the ends of the trough the washing fluid overflows into a receptacle or receptacles where it is collected.

In one embodiment of the invention the deflectors on the troughs are shaped and related to form a baflle in an S-shaped curve. The curve is dimensioned so that the tow may pass through the center section thereof while the washing fluid is directed at a relatively high velocity along a curved path. Along one portion of the washing compartment the baflles are spaced apart to form low velocity areas or chambers by means of which the compartment length can be extended without increasing the pressure drop due to fluid flow. The increased length of the washer compartment is necessary to permit solvent in each fiber to diffuse outwardly after the solvent containing boundary layer of fluid has been removed by passage of the tow through the bafile. The washer can be divided into any number of high velocity washing areas and intermediate diffusion areas as required by the tow thickness, speed and difficulty of washing. Along another portion, the washing compartment consists of a plurality of baflles located side by side to form an area of intense solvent removal.

In this first embodiment the washing fluid from both portions of the washing compartment discharges into a common reservoir from which it is recirculated by a pump to the compartment. To prevent an undue accumulation of solvent in the wash water, a supply conduit opens into the reservoir on the pump inlet and introduces fresh water while an equal amount of solvent containing fluid is overflowed from the reservoir to a drain or to a solvent recovery area.

In another embodiment of the invention the baflles in the washing compartment are formed by planar deflectors on each trough, The washing fluid may exit into a common reservoir from each end of the washing compartment as described above, or alternatively, the fluid from each end may be received in separate reservoirs. In the latter instance the fluid flowing through a first portion of the compartment is recirculated through the other portion of the compartment while fresh washing fluid is introduced into the first portion. In both embodiments it has been found desirable to heat the washing fluid in a suitable manner before it is introduced into the washing compartment.

Accordingly, it is an object of this invention to provide an apparatus for washing a tow of synthetic filaments in which the boundary layer is stripped therefrom by the force of the washing fluid acting at an angle thereto.

A further object of the invention is to provide apparatus for washing a filamentary tow of synthetic material in which the usual boundary layer stripping rolls or bars are replaced by a plurality of baflles which direct a high velocity stream of washing fluid through the tow at an angle.

Another object of this invention is to provide an apparatus for removing a solvent from a filamentary tow of synthetic material in which no mechanical elements are placed in contact therewith.

Still another object of this invention is to provide an apparatus for removing solvent from a filamentary tow of synthetic material in which a flow of washing fluid is established both countercurrent to and with the flow of filaments.

Yet another object of this invention is to provide an apparatus for removing solvent from a filamentary tow of synthetic material in which the washing fluid may be recirculated through a portion of the apparatus.

A still further object of this invention is to provide apparatus which effectively penetrates and removes the boundary layer of washing fluid from all the filaments comprising a tow.

And still another object of this invention is to provide a series of spaced apart baflied sections to allow sufllcient time for solvent diffusion from each filament.

These and other objects and advantages of this invention Will be more apparent upon reference to the following specification, appended claims and drawings wherein:

FIGURE 1 is a partly broken side view of one embodiment of the washing apparatus according to the instant invention showing the interrelationship between the reservoir, troughs, washing fluid supply and draining conduits, and the mechanism for moving the troughs relative to one another;

FIGURE 2 is a cross-sectional view taken along lines 22 of FIGURE 1;

FIGURE 3 is a cross-sectional view taken along lines 3-3 of FIGURE 1 showing a portion of the washing fluid supply and drain system;

FIGURE 4'is a cross-sectional view of the washing compartment according to the embodiment illustrated in FIGURE 1 showing the interrelationship of the baflles and the washing fluid inlet;

FIGURE 5 is an enlarged fragmentary view showing in detail the configuration of a baflle according to the em bodiment illustrated in FIGURE 4;

FIGURE 6 is a cross-sectional view taken along line 66 of the washing compartment illustrated in FIG- URE 4;

FIGURE 7 is a partly cross-sectional view of a washing compartment having planar baffie forming deflectors according to another embodiment of the invention;

FIGURE 8 is a diagrammatic illustration of the fluid flow system according to one embodiment of the invention; and

FIGURE 9 is a diagrammatic view similar to FIGURE 8 but illustrating the fluid supply system according to another embodiment of the invention.

In order to better understand the construction and use of this novel method and apparatus for washing, it will be described in relation to removal of solvent from a filamentary tow of synthetic materials. It is to be understood, however, that various other uses may be found for this novel method and device. For example, it can be utilized for removing excess of unwanted materials or fluids from a finished or partly finished fabric or for dyeing a fabric or tow.

It can also be used to assure penetration of materials or fluids such as a dye-bath, finish additives, delustrants, or various other chemicals wherein it is desired to treat either a tow or a finished cloth uniformly from fiber to fiber and from outside to inside. Other uses will be readily apparent to those skilled in the art.

With continued reference to the accompanying figures wherein like numerals designate similar parts throughout the various views and with initial attention directed to FIGURE 1, reference numeral 10 designates generally a tow washing device according to the instant invention. This device includes a reservoir 12 capable of containing a quantity of washing fluid such as, for example, water supported on a framework 14. A second framework 16 extends above reservoir 12 and, as most clearly shown in FIGURE 2, includes at its uppermost extent an inverted T-bar 18 to which a plurality of pneumatic cylinders 20 4 are secured through a pivot 22. Actuating rods 24 movable within the cylinder 20 in response to the introduction of a compressible fluid such as air extend below cylinders 29 and are pivotably secured through rod clevises 26 to brackets 28.

The compressed fluid is furnished to the cylinders 20 through air lines 36 connected to a plurality of control valves 32. Impelling air is introduced into the cylinders 2t) by manipulation of the lever operated control valve 34 which simultaneously opens or closes the control valves .32 according to the result desired. This system is not considered an essential feature of the invention and could be modified in various ways to obtain the same end result. For example, an electrical-electronic system featuring servo-motors and controls could be utilized just as well.

As most clearly shown in FIGURE 1, the brackets 28 are secured to an inverted trough 36 through bolts 38. The trough 36 is in turn secured to hinge plate 40 which, as shown in FIGURE 2, are pivotally connected at point 42 to an extension 44 of the frame 16. Thus, as actuating rods 24 are drawn into the cylinders 20 under the influence of a compressed fluid supplied through lines 30, the inverted trough 36 pivots upwardly about point 42 to an angular open position. Conversely, the trough is held in its closed position as compressed fluid is utilized to force rods 24 to an outwardly extended position.

A pair of inverted T-

bars

46 and 48 also secured to and forming a portion of the frame 16 are disposed within the reservoir 12 as shown most clearly in FIGURE 2. Nfounted between these bars is another trough 50 secured thereto by bolts 52. As most clearly shown in FIGURES 2, 4, 5, and 6

troughs

36 and 56 form, in combination, a washing compartment 5 having a hollow interior or passageway 56 communicating with entrance 58 and exit 60 apertures through which a filamentary tow or other material to be treated can be passed. As shown in FIGURES 1 and 2, tow guides 62 and 64 are provided at

apertures

58 and 68 to maintain the tow along a desired path.

As most clearly illustrated in FIGURES 4, 5, and 6 the hollow interior or passageway 56 of the washing compartment 54 is formed into a tortuous conduit for fluid by a plurality of

baffles

66 and 67 disposed therein. Immediately adjacent the inlet aperture 58 the batlles 67 are defined by a plurality of deflecting surfaces placed side by side on

troughs

36 and 50. Each deflector includes a cylindrical surface 68 having as its directrix an arc of a circle the center of which is located to one side of the dividing line 69 between

troughs

36 and 50 as will be hereinafter more fully explained. Cylindrical surfaces 68 are joined by connecting surfaces 70 which extend along, and are at least partly parallel to the dividing line 69.

A washing fluid inlet 72 is provided in the washing compartment 54 intermediate its ends. Between washing fluid inlet 72 and aperture 66 the hollow interior or passageway 56 is divided into a tortuous path by bafiles 66 which are spaced from one another to provide chambers 74 in which the tow has an opportunity for additional solvent diffusion therefrom before again being subjected to washing fluid moving at a high velocity through the constriction formed by bafiles 66. As representative of all baffles 66 and to some extent baffles 67 the circled baflle is shown in detail in FIGURE 5.

As shown in FIGURE 5 a tow 76 of synthetic filamentary material moves along a path in the interior passageway 56 which is substantially midway between the bottoms of

troughs

36 and 50 and approximately along the dividing line 69. Each baflle includes a planar surface 78 sloping away from the inlet 72 toward, but terminating at one outermost extent of the path which tow 76 follows. Longitudinally spaced from the planar surface 78 is a cylindrical surface 80 the directrix of which is an arc of a circle centered along one side of the tow 76 path. The directrix of this first cylindrical surface 80 forms substantially a semi-circle having a radius equal to the distance from the path for tow 76 to the bottom of the trough 36. Thus, the first cylindrical surface 80 extends from substantially the tow path to the bottom of the trough and back to the tow path.

Longitudinally spaced from the first cylindrical surface 80 and the planar surface 78 is a second cylindrical surface 82. Again, the directrix of the second cylindrical surface is an arc of a circle centered along the other side of the said tow path and having a radius equal to the distance between said tow path and the associated bottom of the trough 36. This surface, however, extends only from a point substantially at said path for tow 76 to the bottom of the trough where it terminates as clearly shown in FIGURE 5.

Joining the first cylindrical surface 80 and the planar surface 78 is a first connecting surface 84. Likewise, a second connecting surface 86 joins the first and second

cylindrical surfaces

80 and 82 respectively. In order to provide a rapid but smooth flow of fluid through the baflle 66 with minimum fluid energy loss, the planar surface 78 slopes at a relatively mild angle of 20 degrees to a point adjacent the tow path. Since the flow of fluid (as indicated by arrows) tends to displace the tow from the level path illustrated, the first and second connecting

surfaces

84 and 86 are sloped downwardly at approximately degrees to avoid contact with the tow 76 to the greatest extent possible and to provide a snag-free path through the baffle. Otherwise, connecting

surfaces

84 and 86 extend generally parallel to the path along which tow 76 is moved.

The deflecting surfaces formed on the trough 50 as part of the baffle 66 are much like those described above placed, however, in substantially a reversed relationship. Thus, this deflector includes a first cylindrical surface 88 and a second cylindrical surface 90 each of which have a directrix that is an arc of a circle with its center 10- cated along the path for tow 76. Again, the radius of the circle is equal to the distance to the path for tow 76 to the bottom of its associated trough 50. The first cylindrical surface 88 extends from a point substantially at the path for tow 76 to the bottom of trough 50 where it terminates while the directrix of the second cylindrical surface is substantially a semi-circle so that it extends from the path for tow to the bottom of the trough 50 and back to the path for tow.

A first connecting surface 92 extends substantially along the paths for tow 76 and joins first and second

cylindrical surfaces

88 and 90 respectively A second connecting surface 94 joins the second cylindrical surface 90 to a planar surface '96 which slopes downward from a point substantially at one outermost extent of the paths for tow to the bottom of its associated trough 50. The planar surface 96 is inclined at an angle of approximately de grees to the path for tow 76 while the first connecting surface 92 has a partly sloping surface which, again, is at an angle of approximately 10 degrees with respect to the path for tow to provide a smooth, snag-free passageway for the tow 76. The small angle of surface 96 allows the moving fluid to expand into the diffusion chamber with a minimum loss of fluid energy, according to well established fluid flow principles.

The deflecting surfaces on trough 50 and trough 36 are related so that when combined a baflie is produced constricting the passageway 56 into a substantially S- shaped curve. Thus, the radii of the various directrix of the cylindrical surfaces, all of which are equal in length asexplained above, are spaced along said path for tow 76 such that they overlap to an extent suflicient to provide a constricted, and hence high velocity, fluid passageway along the deflecting surface formed by cylindrical surface 80 and the deflecting surface formed by cylindrical surface 90. For example, where the radii of these directrix measure one-fourth inch, the directrix centers will be spaced apart 0.406 inch, an amount equal to approximately the sum of two radii minus approximately one-fifth the sum.

In order to provide a clear path for tow through the baffles 66, the centers of the directrix of the cylindrical surfaces and 82 formed in trough 36 and the outermost extent of first and second connecting

surfaces

84 and 86 and planar surface 78 lie in a plane which is disposed slightly to the trough 36 side of the path for tow 76. Likewise, the centers of the directrix for first 88 and second cylindrical surfaces and the outermost extent of planar surface 96 and connecting

surfaces

92 and 94 formed on trough 50 lie in a plane disposed to the trough 50 side of the path for tow 76. Thus, all deflector surfaces formed on trough 36 and trough 50 are spaced from one another a distance equal to at least the thickness of the path for tow 76.

As clearly shown in FIGURE 4 alternate baflles 66' are formed by reversing the position of the deflector surfaces on

troughs

36 and 50. In this manner, the planar and first and second

cylindrical surfaces

80 and 82 and their associated connecting

surfaces

84 and 86 are inverted and formed on trough 58. In a like manner planar surface 96, first and second

cylindrical surfaces

88 and 90 and their associated connecting

surfaces

92 and 94 are inverted and formed on trough 36. While not absolutely necessary, this reversal does result in smoother fluid flow and minimum fluid energy losses, and hence, additional etficiency in the utilization of washing fluid.

The outermost baffle 66" at aperture 60 is very similar to baffle 66 except that the second cylindrical surface corresponding to second cylindrical surface 82 has. like cylindrical surface 80, as its directrix an arc which is substantially a semi-circle. This, in conjunction with the angular planar surface extending at approximately a 60 degree angle to the path for tow, directs the flow of washing fluid downwardly into the reservoir 12 to prevent excessive splattering.

The baflies 66 are not illustrated in detail since they are substantially identical in their formation and relationship as the deflector surfaces formed by cylindrical surface 80 and cylindrical surface 90 illustrated in FIG- URE 5. Again, the radii of the directrix of these two surfaces overlap as described above and their centers are l cated relatively to the tow path in the same position. Furthermore, the length of these radii is, again, equal to'the distance from the trough side of the tow path with which it is associated to the bottom of that trough. Connecting surfaces 70 are substantially identical to connecting

surfaces

86 and 92 as shown in FIGURE 5 except that they slope oppositely, as shown, to compensate for the fact that washing fluid flows through these bafiies in a different direction as shown by the arrows. As shown, the

planar surfaces

78 and 96 as well as the half

cylindrical surfaces

82 and 88 are eliminated and a series of cylindrical surfaces similar to those shown at 80 and 90 in FIGURE 5 are placed side by side to form an undulating, tortuous passageway for fluid. At the entrance aperture 58, a planar surface is provided again to, in combination with the last cylindrical surface, direct washing fluid downwardly into the reservoir 12. Another curved surface 104 is provided at the inlet side of this tortuous passageway formed by baflies 67 to direct the washing fluid along the desired course.

As shown in FIGURES 2 and 8, the Washing water inlet 72 is connected through a conduit 106 to a pipe 108 extending through a heat exchanger 110 to a pump 112. The inlet 114 of pump 112 is connected through

pipes

116 and 118 to a screened drain 120 in reservoir 12. By this arrangement wash water is recirculated from the reservoir 12 as a conservation measure. To prevent solvent concentration from becoming excessive, a continuous overflow is maintained through the screened drain 122 at the same time a continuous supply of fresh, relatively solvent-free washing fluid is supplied through a pipe 124. The amount of solvent concentration can, therefore, be regulated merely by increasing or decreasing the amount of solventfree fluid introduced through pipe 124. Complete drainage of reservoir 12 is eifected by opening valve 126 and ceasing operation of the pump 112.

In operation, a filamentary tow is threaded through the washing compartment 54 by raising the trough 36 under influence of the action of pneumatic cylinders acting through actuating rods 24. After threading, the trough 36 is returned to its closed position and operation of the pump 112 commenced to force washing fluid through the inlet 72. Upon reaching the interior passageway 56 of the washing compartment 54, the washing fluid divides with part flowing through the bafiies 66 and part through the baffles 67. Tow entering through aperture 58 and exiting through aperture 6 1' is subjected to a countercurrent flow of fluid as it passed along baffles 67 and at the same time a high velocity flow alternately from above and below its path. This action tends to spread the tow and force water therethrough, breaking the boundary layer and achieving good penetration and hence a thorough washing.

As the tow continues through the hollow interior 56 across

baflles

66, 66' and 66" it is subjected to a flow of washing water moving in the same direction but, usually, at a greater velocity. Thus, in this section the washing action is more gentle while at the same time maintaining good penetration of the tow to remove the desired amount of residual solvent or other unwanted ingredients. Again, penetrating from above and below is achieved by flow of fluid from these directions.

In the embodiment of the invention illustrated in FIG- URE 7, the washing compartment 54' is formed by a pair of troughs 36 and 50' fitted together and relatively hinged as illustrated in FIGURE 1. When in operative position as shown, a hollow interior passageway 56' is formed similarly to the embodiment illustrated specifically in FIGURES 4 and 5. This hollow interior passageway 56' communicates with an inlet aperture 128 and an outlet aperture 130 through which tow 76 may be passed as indicated by the arrow. The interior of this passageway is formed into a tortuous, undulating conduit for washing fluid by a plurality of bafiies, each of which is formed by a deflector 132 on trough 36' alternately spaced with a deflector 134 on trough 50'. As illustrated these

deflectors

132 and 134 are planar and extend substantially perpendicular to the bottom of its associated trough bottom and terminate in closely spaced relationship to one another to form a relatively obstacle free path through which tow 76 may pass. The arrangement of

deflectors

132 and 134 is such, however, as to form a tortuous, undulating path for fluid as shown by the arrows so that the tow is alternately subjected to a high velocity flow directed therethrough at a substantially right angle from above and then from below.

Washing fluid is introduced into the interior passageway 56' of the washing compartment 54 at a point substantially equidistant from inlet and

outlet apertures

128 and 130. Washing fluid passes through an inlet distribution head 136 which projects into the hollow interior 56' and divides it into a first portion 138 between the head 136 and the outlet aperture 130 and a second portion 140 between the head 136 and the inlet aperture 128. The inlet head 136 is divided into first and

second chambers

142 and 144 respectively and is arranged so that the dividing line therebetween is located exactly opposite a deflector 132 on the trough 36. Washing fluid is introduced into the first chamber 142 through a pipe 146, and similarly, washing fluid is introduced into the second chamber 144 through a pipe 148. Fluid flow is maintained at a constant rate through both first and

second chambers

142 and 144 in a manner hereinafter described so that the volumes of fluid passing through the

washing compartment portions

138 and 140 are equal. As shown by the arrows, the washing fluid passing through each portion is directed by the various deflectors along a tortuous and undulating course.

While it is obvious that the embodiment of the invention illustrated in FIGURE 7 can be utilized with the fluid supply system illustrated in FIGURE 8 and described above, an alternate supply system is illustrated in FIG- URE 9. As shown in FIGURE 9, the reservoir 12' is divided in such a manner as to provide a first receptacle 150 at the outlet end of washing compartment 54'. A screened drain 154 is provided in the bottom of receptacle 150 and is connected through tubing 156 to the inlet of a pump 153. As shown in FIGURE 9 the pump 158 is connected through a throttling valve 160, pipe 162, and heat exchanger 164 to pipe 148 which exits into the second chamber 144 of the inlet head 136. The first chamber 142 of inlet head 136 is connected through pipe 146 to a heat exchanger 166 and thence through a pipe 168 to a supply of fresh washing fluid. A regulated supply of steam is provided to

heat exchangers

164 and 166 from a steam supply to maintain the washing fluid at the desired temperature.

In operation, fresh washing fluid passes through heat exchanger 166 where its temperature is elevated, through the first inlet head chamber 142, through first washing compartment portion 138 and thence into receptacle 150 where it is collected. This fluid is then conducted through drain 154 and pipe 156 to pump 158 and thence through heat exchanger 164 into the second chamber 144. From chamber 144 the fluid passes into the second portion of washing compartment 54 and into receptacle 152. The washing fluid is then either disposed of through a screened drain 170 or directed to a solvent recovery device. The amount of fluid in receptacle is maintained at a preselected level by control 172 which operates throttle valve in a well known manner. Thus, the volume of fluid passing through

portions

138 and 140 is maintained equally in thefollowing manner. If the amount of fluid passing through portion 138 increases the level in receptacle 159 will also increase and such is sensed by level control 172. After a slight rise in level the throttling valve 160 is adjusted to allow passage of more fluid into the second compartment portion 140. Obviously, if the level of fluid in receptacle 150 falls, the throttle 160 will be adjusted to lessen the volume passed through second portion 140.

As tow 76 passes through aperture 128, and along second washing compartment portion 140 it is subjected to a countercurrent flow of washing fluid alternately forced therethrough from above and below at high velocity. Passing on into first trough portion 138 the tow 76 is subjected to a concurrent flow of fluid which is again alternately forced therethrough from above and below. In this manner the tow which comprises a plurality of synthetic filaments is repeatedly penetrated to remove unwanted residual ingredients.

It will be apparent that by utilizing the apparatus and method for washing filamentary tows which is the subject of this invention, a much more efficient and effective removal of solvent is accomplished. This result is obtained without utilizing boundary layers, stripper bars, 01' rolls as has heretofore been the practice. In addition to improving the effectiveness of tow washing, this novel apparatus and method enables the washing of larger tows in a relatively small floor space due to the more eflicient use of the washing fluid. Thus, more efficient utilization of both floor area and washing fluid can be accom plished resulting in the saving of both time and capital to a significant degree.

The same principles of high velocity Washing that assures intimate contact of the washing fluid with every fiber of a tow can be applied when it is desired to contact every fiber of a tow or fabric with a chemical or other substance in a fluid vehicle. In the first case, intimate contact of solvent containing fiber with relatively solvent free fluid allows diffusion of solvent from the fiber to the fluid. In the opposite case, intimate contact of a chemical poor fiber arrangement with a chemical rich fluid will encourage uniform diffusion, if such can occur, of the chemical from the fluid into the fibers,

It may be further noted that, since the fluid is introduced into the intermediate portion of the apparatus and fluid flow is towards opposite ends which are open to the atmosphere, it is obvious that the fluid pressure at the point of introduction is higher than atmospheric. This means that a fluid may be introduced into the apparatus at a temperature higher than its atmospheric boiling point. The apparatus may thus be considered a pressure vessel wherein a fluid of a higher than normal temperature may be used. For instance, if water is introduced into the washer at an inlet pressure of 25 p.s.i.g. (39.7 p.s.i.a.), it can be introduced at a temperature up to 265 F. rather than a temperature of 212 F. This does result in considerable flashing off of steam as the water drops in pressure in passing through the washer. Generally, it is more practical to utilize some maximum temperature intermediate the atmospheric boiling point and the boiling point at the pressure indicated. Otherwise, the percent of vapor to fluid impairs the efficiency of the fluid action.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

I claim:

1. Apparatus for treating a filamentary tow comprismg:

(a) a first elongated trough having a channel extending from end to end thereof;

(b) a second elongated trough having a channel extending from end to end thereof;

(c) said first and second troughs movably secured together to form an elongated compartment defined by said channels and including a passageway extending therethrough adapted to receive a filamentary tow;

(d) an inlet opening into said compartment intermediate said ends and adapted to supply a treating fluid to said passageway; r

(e) at least one deflector means on each of said first and second troughs disposed across said channels and extending into said passageway to form in combination a passageway baffle;

(f) said deflectors closely, spacedly terminating at their outermost extent to define a path through said compartment for passing tow and a tortuous conduit through said compartment for said fluid whereby said fluid will be repeatedly directed toward and through filamentary tow in said passageway at substantially right angles.

2. Apparatus according to claim 1 wherein a plurality of said passageway baffles are formed by a plurality of planar deflectors extending outwardly from the bottom of each of said channels with the deflectors of one channel spaced intermediate the deflectors of the other channel.

3. Apparatus according to claim 2 in which each end of said passageway terminates in a separate receptacle adapted to contain said fluid and wherein:

(a) said inlet comprises first and second fluid inlets disposed in contiguous relationship and dividing said compartment into first and second portions;

(b) one of said deflectors disposed intermediate said first and second inlets and arranged to direct treating fluid from said first inlet into said first compartment portion and from said second inlet into said second compartment por'ton whereby both a flow of. fluid countercurrent to tow movement and with tow movement will be established.

() said receptacle at the end of said first compartment portion connected through a pump to said second inlet whereby fluid from said first portion is circulated through said second portion; and

(d) means for determining the fluid level in said receptacle at the end of said first compartment portion and changing the fluid flow rate from said receptacle to said second inlet to mainttain said fluid level constant and thereby the volume of said fluid in said first and second compartment portions equal.

4. Apparatus according to claim 1 wherein said deflectors are shaped to form a batfle constricting said passageway into a substantially S-shaped curve.

5. Apparatus according to claim 1 wherein said deflector on said first trough is defined by:

(a) a planar surface sloping outwardly from the bottom of said channel away from said outlet toward said path;

(b) a first cylindrical surface, the directrix of which is an arc of a circle centered along said path for tow at a point spaced from said planar surface, said first cylindrical surface extending from said path to substantially the bottom of said channel and outwardly from said channel bottom to said path;

(c) a second cylindrical surface, the directrix of which is an arc of a circle centered along said path for tow at a point spaced from said cylindrical surface directrix center, said second cylindrical surface extending from said path to substantially the bottom of said channel; and

(d) first and second connecting surfaces extending along said paths and joining said planar surface and said first cylindrical surface and said first cylindrical surface and said second cylindrical surface respectively.

6. Apparatus according to claim 5 wherein said deflector on said second trough is defined by:

(a) a first cylindrical surface, the directrix of which is an arc of a circle centered along said path for tow, said first cylindrical surface facing said inlet and extending from the bottom of said channel to said path;

(b) a second cylindrical surface the directrix of which is an arc of a circle centered along said path for tow at a point spaced from said cylindrical surface directrix center, said second cylindrical surface extending from said path to substantially the bottom of said channel and outwardly from said channel bottom to said path;

(c) a planar surface sloping outwardly from said paths and intercepting said channel bottom on said second trough; and

(d) first and second connecting surfaces extending along said path and joining and intersecting said first and second cylindrical surfaces, and said second cylindrical surfaces and said planar surface respectively.

7. Apparatus according to claim 6 wherein:

(a) said directrix centers for said cylindrical surfaces defining a portion of said deflector on said first of said troughs lie in a plane extending parallel to said path for tow located between said path for tow and said bottom of said channel in said first trough; and

(b) said directrix centers for said cylindrical surfaces defining a portion of said deflector on said second of said troughs lie in a plane extending parallel to said path for tow and located between said paths for tow and the bottom of said channel in said second trough.

8. Apparatus according to claim 7 wherein said path for tow lies midway between the bottoms of said channels whereby said passageway is symmetrical about said path.

9. Apparatus according to claim 8 wherein the radii of said directrix circles are the same length and are equal to substantially one-half the depth of said passageways less the thickness of said path for tow.

10. Apparatus according to claim 9 wherein said baffle is defined by said deflector on said first trough and said deflector on said trough related to a point in said passage- 1 1 Way such that the directrix radii defining said first trough deflector overlap directrix radii defining said second trough deflector.

11. Apparatus according to claim 9 wherein:

(a) said directrix radius of said first cylindrical surface of said deflector on said first trough overlaps said directrix radius of said first cylindrical surface of said deflector on said second trough;

(b) said directrix radius of said second cylindrical surface of said deflector on said second trough overlaps both the directrix radii of said first and second cylindrical surfaces of said deflector on said first trough.

12. Apparatus according to claim 11 wherein said directrix centers are equally spaced from one another along said path for tow at a distance substantially equal to the sum of their radii less substantially one-fifth said sum.

13. Apparatus according to claim 12 wherein:

(a) said first connecting surface of said deflector on said first trough slopes away from said path for tow toward the bottom of said first trough;

(b) a portion of said second connecting surface of said deflector on said first trough slopes away from said path for tow toward the bottom of said first trough and intercepts said second cylindrical surface; and

(c) a portion of said first connecting surface of said deflector on said second trough slopes away from said path for tow toward the bottom of said second trough intercepting said second cylindrical surface on said second trough.

14. Apparatus according to claim 12 wherein:

(a) the slope of said first and second connecting surfaces of said deflector on said first trough and the slope of said first connecting surface and said planar surface of said deflector on said second trough is substantially ten degrees from said path for tow; and

(b) the slope of said planar surface of said deflector on said first trough is substantially twenty degrees from the path for tow.

15. Apparatus according to claim 14 wherein a plurality of baflies are spacedly disposed along said passageway and are constructed and arranged such that alternate ones are formed by reversing said deflectors so that said surfaces of said deflector on said first trough are on said second trough and said surfaces of said deflector on said second trough are on said first trough.

16. Apparatus according to claim 15 wherein low fluid velocity chambers are disposed between said baflies.

17. Apparatus according to claim '16 wherein said baffles are disposed between one end of said passageway and said inlet.

18. Apparatus according to claim 17 wherein baflies are disposed between the other end of said passageway and said inlet and comprise:

(a) deflectors formed alternately on said first trough and on said second trough;

(b) each deflector including a cylindrical surface the directrix of which is an arc of a circle centered along said path for tow and extending from said path for tow to substantially the bottom of said channel and outwardly from said channel bottom to said path, and a connecting surface extending along said path and joining and intersecting the cylindrical surface of the adjacent deflector;

(c) said directrix centers disposed in planes parallel to said path for tow and located between said path for tow and the bottom of the channel on which its associated cylindrical surface is disposed;

(d) said path for tow lying midway between the bottoms of said channels whereby said compartment is symmetrical about said path;

(c) said radii of said directrix circles being the same length and equal to one-half the depth of said compartment less the thickness of said path for tow;

(f) said directrix radii of said deflectors on said first trough overlapping said directrix radii of said deflectors on said second trough; and

(g) said directrix centers equally spaced from one another along said path for tow at a distance equal to substantially the sum of their radii less substantially one-fifth that sum.

19. Apparatus according to claim 18 wherein said passageway terminates in a receptacle adapted to contain said treating fluid and including means for supplying heated treating fluid thereto.

20. Apparatus according to claim 1 wherein said baflles comprise:

(a) said deflectors formed alternately on said first trough and on said second trough;

(b) each deflector including a cylindrical surface the directrix of which is an arc of a circle centered along said path for tow and extending from said path to substantially the bottom of said channel and outwardly from said channel bottom to said path, and a connecting surface extending along said path and joining and intersecting the cylindrical surface of an adjacent deflector.

21. Apparatus according to claim 20 wherein said directrix centers are disosed in planes parallel to said path for tow and located between said path for tow and the bottom of the channel on which its associated cylindrical surface is formed.

22. Apparatus according to claim 21 wherein said path for tow lies midway between the bottoms of said channels whereby said passageway is symmetrical about said path.

23. Apparatus according to claim 22 wherein the radii of said directrix circles are the same length and are equal to one-half the depth of said compartment less the thickness of said paths for tow.

24. Apparatus according to claim 23 wherein said directrix radii of said deflectors on said first trough overlap said directrix radii of said deflectors on said second trough.

25. Apparatus according to claim 23 wherein said directrix centers are equally spaced from one another along said path for tow at a distance equal to substantially the sum of their radii, less substantially one-fifth said sum.

26. Apparatus according to claim 25 wherein said connecting surface extending along said paths-and joining and intersecting the cylindrical surface of an adjacent deflector slopes away from said path for tow toward the bottom of the channel on which it is disposed at substantially an angle of 10 degrees to said path for tow.

References Cited UNITED STATES PATENTS 1,897,122 2/1933 Hartmann et al. 2,558,734 7/1951 Cresswell 68l81 2,642,035 6/ 1953 McDermott 68181 X 3,267,704 8/ 1966 Muller.

FOREIGN PATENTS 661,941 4/1963 Canada. 288,900 11/1915 Germany.

IRVING BUNEVICH, Primary Examiner.

Claims

1. APPARATUS FOR TREATING A FILAMENTARY TWO COMPRISING: (A) A FIRST ELONGATED TROUGH HAVING A CHANNEL EXTENDING FROM END TO END THEREOF; (B) A SECOND ELONGATED TROUGH HAVING A CHANNEL EXTENDING FROM END TO END THEREOF; (C) SAID FIRST AND SECOND TROUGHS MOVABLY SECURED TOGETHER TO FORM AN ELONGATED COMPARTMENT DEFINED BY SAID CHANNELS AND INCLUDING A PASSAGEWAY EXTENDING THERETHROUGH ADAPTED TO RECEIVE A FILAMENTARY TOW; (D) AN INLET OPENING INTO SAID COMPARTMENT INTERMEDIATE SAID ENDS AND ADAPTED TO SUPPLY A TREATING FLUID TO SAID PASSAGEWAY; (E) AT LEAST ONE DEFLECTOR MEANS ON EACH OF SAID FIRST AND SECOND TROUGHS DISPOSED ACROSS SAID CHANNELS AND EXTENDING INTO SAID PASSAGEWAY TO FORM IN COMBINATION A PASSAGEWAY BAFFLE; (F) SAID DEFLECTOR CLOSELY, SPACEDLY TERMINATING AT THEIR OUTERMOST EXTENT TO DEFINE A PATH THROUGH SAID COMPARTMENT FOR PASSING TOW AND A TORTUOUS CONDUIT THROUGH SAID COMPARTMENT FOR SAID FLUID WHEREBY SAID FLUID WILL BE REPEATEDLY DIRECTED TOWARD AND THROUGH FILAMENTARY TOW IN SAID PASSAGEWAY AT SUBSTANTIALLY RIGHT ANGLES.