US3394925A - Apparatus for mixing abrasive liquids - Google Patents

Description

July 30, 1968 R. SLUIJTERS APPARATUS FOR MIXING ABRASIVE LIQUIDS 3 Sheets-Sheet 1 Filed May 16, 1966 FIG.I

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July 30, 1968 R. SLUIJTERS 3,394,925

APPARATUS FOR MIXING ABRASIVE LIQUIDS Filed May 16, 1966 3 Sheets-Sheet 2 FIG INVENTOR.

ROBERT SLUI J TERS BY W July 30, 1968 R. SLUIJTERS APPARATUS FOR MIXING ABRASIVE LIQUIDS 3 Sheets-Sheet 3 Filed May 16, 1966 mm in mm INVENTOR.

ROBERT SLUIJTERS United States Patent 3,394,925 APPARATUS FOR MIXING vABRASIVE LIQUIDS, Robert Sluijters, Arnhem, Netherlands, assignor to American Enka Corporation, Erika, N.C., a corporation of Delaware Continuation-impart of application Ser. No. 536,776, Mar. 23, 1966. This application May 16, 1966, Ser. No. 550,227 r i I f Claims priority, application Netherlands, May 29, 1965, 6506835 4 Claims. (Cl. 25925) ABSTRACT on THE DISCLOSURE Apparatus for admixing an abrasive-containing component with a liquid especially suitable for being manufactured into film, filaments, fibers or yarns comprising a plurality of serially arranged gear pumping means positioned in a single housing, a first of said pumping means constructed to meter an unmixed liquid to a second and third pumping means, the second pumping means constructed to meter a portion of the unmixed liquid from the first pumping means through a conduit system in order to wash and lubricate moving parts of the third pumping means, said third pumping means constructed to meter the abrasive component to a main stream of viscous liquid flow.

The application is a continuation-in-part of US. application Ser. No. 536,776, filed Mar. 23, 1966, now US. Patent No. 3,368,799 commonly assigned herewith.

This invention relates to apparatus for supplying to a stream of viscous liquid an additive having a relatively low viscosity and having an abrasive component suspended therein.

Various methods and apparatus for supplying or injecting an abrasive additive into a bypass stream of a main stream of viscous liquid flow are known and many often employ intermittently operating or constantly operating pumps for adding such additives as suspensions to a stream of a relatively high viscosity spinning solution used in the manufacture of artificial threads, fibers, filaments and yarns. The low viscosity materials are usually suspensions of various coloring or delustering materials such as titanium dioxide and are by nature very abrasive and damaging to equipment through which they pass. For the purposes of improving the color, such abrasive additives are preferably injected into the bypass stream between two or more gear pumps, an expedient particularly expounded upon in the above-identified patent. In the patent, it has been shown that, when using this expedient to add colorants having an abrasive component, rapid wear occurs in various apparatus elements feeding such abrasives and to which they come in contact. Locus of wear is especially pronounced in prior art apparatus in the gear coupling arrangement for metering and feeding the liquid side stream back to the main stream of untreated viscous liquid flow. The abrasive suspensions being introduced easily get between side faces of gears, boundaries thereof, and bearings for the drive shaft and as an end result and after a period of time, cause excessive wear. As a result, the liquids are not effectively mixed and metered to the spinning assembly.

Although the apparatus according to the above-identified copending patent has shown an effective manner in which to solve wear problems, particularly on one pump positioned with a series of pumps, a few disadvantages have been found. For example, when practicing the teaching according to the earlier filed patent, at least three pumps must be used in the branch conduit into 3,394,925 Patented July 30, 1968 which the abrasive component is being added. Two of these gear pumps are arranged in series and are separated from each other by an inlet for the abrasive component suspension and a third gear pump is located in a second conduit branching off from the main conduit feeding the unmixed spinning liquid. This third gear pump feeds unmixed washing and lubricating liquid to the second of said gear pumps in the series and prevents the abrasive components of the suspension being added to the main liquid flow stream from coming in contact with various moving components of the pump where normally excessive wear occurse.g., gear side faces, drive shaft bearings, etc. Disadvantages associated with this arrangement reside in the fact that the three gear pumps must be separately driven, an expedient which requires rather complicated construction. For example, the three pumps each require three separate driving mechanisms having to be separately sealed and further having a separate and distinct lubricating system. More importantly, it has been found that if the ratio of the amount of pigment suspension to that of spinning liquid is to be changed and readjusted, a complicated and time consuming procedure is required to adapt the apparatus to such a change.

Thus, it is an object of this invention to provide an apparatus for reducing or entirely avoiding wear of a gear pump used for metering an injected abrasive liquid to a main liquid flow stream by providing a compact pump coupling arrangement and means preventing an abrasive component from contacting and wearing away surfaces thereof.

These and other objects of the present invention are achieved by a novel three pump arrangement provided as a unit in a single housing and having means with a common drive shaft for metering a plurality of liquid streams through a unique system of interconnecting conduits. The invention provides means for continuously mixing a number of streams of different composition into a single stream by providing arbitrarily arranged gear couplings permitting a metered flow. Further, the unique arrangement of the channels permitting metering of the liquids to be admixed also provides for an effective washing of the pumping gear coupling through which the abrasive component passes. This washing and lubricating is principally achieved by mounting the pumps in a plate pack arrangement and having one gear coupling metering a washing and lubricating liquid to the particular pump through which the abrasive component passes and preferably positioned between two sets of gear couplings.

Another advantage facilitated by the construction of the present invention resides in the means for easily changing the ratio of the abrasive suspension to the highly viscous unmixed spinning liquid in the bypass stream. In having a common drive shaft for the three gear couplings, a mixer used for initial mixing and forming a suspension of the abrasive component in a lower viscosity carrier liquid facilitates a direct mechanical coupling between a stirrer of the mixer and the drive shaft. The two elements can now be effectively interconnected by a speed regulator. Control of the speed regulator controls the rate of mixing action and delivery of the lubricating pump as Well as the rate of the feed of the suspension to the bypass stream.

For the purposes of this invention, a set or a gear coupling is a cooperating gear arrangement, known in the art, providing for metered liquid flow through the apparatus and to the viscous liquid to which an abrasive component is being added. The coupling, of course, can be used to feed a liquid which has not been admixed with an abrasive suspension or a liquid which has been admixed with an abrasive suspension.

A plate pack arrangement is a series of plates which, according to this invention, is channeled to provide a unique system of flow channels for both the liquid material to be admixed and the liquid material serving as the lubricating and washing component for the various moving parts of the apparatus set out in more detail below. The plate pack further acts to contain, position and provide a proper proximal relationship between opposed gear couplings pumping and metering the liquids passing through the apparatus.

In the drawings which illustrate preferred embodiments of the invention:

FIGURE 1 is a schematic representation of the apparatus;

FIGURE 2 shows a detail of the apparatus in longitudinal section useful in carrying out the invention; and

FIGURE 3 shows the same detail in longitudinal section along lines IIIIII of FIGURE 2.

Particularly referring to FIGURE 1, numeral 1 represents the entire pump assembly according to the invention shown schematically, with externally assembled mixing container 2 having a stirrer or mixing blade assembly. Pump assembly 1 and mixing blades 16 are driven by shafts 3 and 4, respectively, which by way of gears 5 and 6, are driven by a gear 7 mounted on the output shaft of a speed regulator 8. In turn, speed regulator 8 is driven by an electric motor 9. The main stream of a spinning liquid is pumped through conduit 10 by a gear pump (not shown). From conduit 10 there leads off a conduit or side stream 11 which runs to the pump assembly 1.

Through this sidestream of spinning liquid an abrasive suspension will eventually be added. The abrasive is initially fed to the apparatus through conduit 12 and into mixing container 2. After the abrasive suspension and the sidestream of spinning liquid have been joined and mixed, they are passed through conduit 13 and returned to conduit 10 which is used to feed the major portion of spinning liquids. The mass fed from conduit 13 and the liquid flowing through conduit 10 (containing unmixed liquid) are thoroughly mixed by a mixer 18 usually immediately before being passed to a spinning point. This spinning point may be of conventional design. Mixer 18 can be of the type particularly described in US. Patents Nos. 3,051,452 and/or 3,051,453.

The suspension is fed to the spinning liquid by initially bringing together in the mixer a stream of the suspension being supplied through conduit 12 and a spinning liquid being pumped through conduit 14 from pump assembly 1. From mixer 2 (through conduit 15 to pump assembly 1) an amount of liquid is discharged which is equal to the sum of amounts of liquid fed per unit time through conduits 12 and 14 to mixer 2. Thus, the apparatus by its design effectively meters the amount of pigment suspension being pulled through conduit 12. Mixer 2 is of known design and comprises driving shaft 4 fixedly positioning radially extending pins or blades 16. Blades 16 rotate between fixed pins 17 attached to and extending outwardly from the inside wall of the mixer housing.

Pump assembly 1 comprises three gear pumps having gears 19, 20 and 21 mounted on drive shaft 3. The three gears are coupled with gears 22, 23 and 24 which are freely rotatable. Conduit 11 feeds to the intake opening adjacent to the first pumping gear couple formed by gears 19 and 22. This gear couple displaces the liquid mainly through conduit 14 to mixing container 2 while the remainder of the liquid is displaced through conduit 25 to the pumping gear couple formed by gears 20 and 23. This unmixed liquid being pumped by gears 20 and 23 acts as the lubricating liquid. The relatively small proportion of liquids applied through conduit 25 is displaced by the pumping couple formed by gears 20 and 23 through conduit 26 and subsequently through conduits 27, 28, 29 and 30.

The liquid being supplied through conduit 15 is pumped by the pumping couple formed by gears 21 and 24 through conduit 13 and back to main conduit 10. Channels 27, 28, 29 and 30 feed into points where drive shaft 3, shaft 48, and gears 21 and 24 are supported by bearings. The liquid supplied by the lubricating pumping gear couples 20 and 23 will flow through these bearings radially outwardly along the side face of gears 21 and 24 and to the circumferential surfaces of said gears. From this point the liquid is further pumped through conduit 13. This unique system of channels prevents the abrasivecontaining liquid flowing from the space between the teeth of gears 21 and 24 to between the side faces of the gears and the stationary plates of pump assembly 1. This prevents any wear which usually occurs in known types of apparatus.

Should the speed of output shaft of regulator 8 be increased, then gears 19 and 22 would pump proportionately more liquid through conduit 11 from the main conduit 10 which carries the major portion of the spinning liquid. Further, the amount of liquid returned to the main conduit 10 through conduit 13 by the gears 21 and 24 will also increase proportionately. The total amount of liquid flowing through mixer 18 will now show an increase that corresponds only to the increase in the amount of abrasive suspension pulled through conduit 12. This increase likewise is proportional to the speed of the output shaft of speed regulator 8. In actual practice, the percentage of abrasive suspension contained in the spinning liquid is usually very small and, as a result, the variations in the total delivery of the apparatus will likewise be negligible. Thus, as an attendant advantage, the apparatus is especially suitable in controlling even minute variations in pigment content in the abrasive content of a spun filament without any appreciable increase in filament size or denier.

Now particularly referring to FIGURES 2 and 3, the pump assembly is shown being made up of a number of fiat plates 31 through 43 which form a plate pack (together with a bearing housing 44 for drive shaft 3). Drive shaft 3 passes through the bearing housing and the passage is sealed by means of packing assembly 45. Gears 22, 23 and 24 are attached to shafts 46, 47 and 48 mounted in plate pairs 32, 34, 36, 38, 40 and 42, respectively. Within the pump assembly, drive shaft 3 consists of several short sections on which the gears 19, 20 and 21 are mounted. These are intercoupled by the coupling members 49, 50 and 51 rotatable in plates 35, 39 and 43, respectively. Plates 33, 37 and 41 are provided with openings which contain gear couples 19 and 22; 20 and 23; 21 and 24, respectively. The conduits 11, 14, 15 and 13 of FIGURE 1 run partly through plates 31, 35, 39 and 43. Channels 25 to 30, inclusive (shown in FIGURE 1) are bores through the pack formed by the plates 31 to 43, inclusive, and the bearing housing 44. Lubricating liquid flows through the channels 28 and 29 to the ends of shaft 48. The liquid then flows in an axial direction to gear 24 and in a radial direction over the side faces thereof and then to the spaces between the teeth of the coacting gears.

To especially facilitate the flow of the liquid along the journals of drive shaft 48 there are provided grooves 53 and 54. By rotation of the drive shaft, such grooves, in fact, provide a pumping action to the lubricating liquid. Similarly, the lubricating liquid is guided to the channels 27 and 30 to coupling member 50 and to the collar on the drive shaft 3, respectively. The direction of flow of the liquids is indicated by the arrows. The various coupling members 50 and 51 are also provided with pumping grooves 52 and 55, which facilitate the flow of the liquid from points of entrance in channels 27 and 30 and in the direction of gear 21.

As one skilled in the art would appreciate, the entire pump assembly is of a very compact construction and facilitates the incorporation of the unique system of conduits. The drive assembly does not present any problems whatsoever in the operation of the apparatus as described above and may be varied in any desired manner.

It has been found in the production of colored textile filaments and fibers, the apparatus ermits spinning pigmented filaments yielding highly satisfactory filaments and fibers, particularly when compared with filaments and fibers wherein the color is added by known means. From the standpoint of quality, the filaments and fibers formed when using apparatus according to this invention are not just colored on the surface but possess a generally uniform colored cross-section. Consequently, the colors of such filaments and fibers are less sensitive to the effects of chemical action and effects of heat and light. Moreover, eliminating the need for frequent changing of parts, as is characteristic to known apparatus, improves the cost factor of the process.

What is claimed is:

1. Apparatus for admixing an abrasive-containing component with a higher viscosity liquid suitable for being formed into film, filaments, fibers, yarns or threads, comprising in combination,

(a) a plurality of pumping means serially and cooperatively positioned within a single housing,

(b) said plural pumping means having a common drive means and a system of interconnecting conduits for liquid flow,

(c) said drive means driving at least one gear in a cooperating pumping gear pair in each of said plural pumping means,

(d) said conduits constructed to confine and properly channel an unmixed viscous liquid, an abrasive component, and a mixed viscous liquid-abrasive component being pumped by said plural pumping means,

(e) a first of said plural pumping means, comprising a gear couple, constructed to meter an unmixed, viscous liquid to a second and third pumping means,

(if) the second pumping means, comprising a gear couple, constructed to meter a portion of the unmixed liquid from the first pumping means through a conduit system to lubricate and wash the drive shaft, bearins and gears comprising elements of the third pumping means, and

(g) said third pumping means constructed to meter the said abrasive component to a main stream of viscous liquid flow.

2. Apparatus according to claim 1 wherein said housing supports and maintains the plurality of pumping means and is constructed of a series of juxtaposed plates of varying thickness.

3. Apparatus according to claim 1 wherein a separately housed mixer is provided for admixing said abrasive component and said viscous liquid, a plurality of stirrer means mounted on a drive shaft in said mixer, and means mechanically interconnecting said shaft to the drive shaft for the said plural pumping means through a speed regulating means.

4. Apparatus as defined in claim 3 wherein there is provided conduit means for fluid flow between said mixer and said pumping means.

References Cited UNITED STATES PATENTS 796,724 8/ 1905 Hewitt. 1,665,026 4/ 1928 Grant. 1,689,673 10/1928 Lalor. 2,125,455 8/1938 McLean 2599 2,207,493 7/ 1940 Van Dartelen. 2,986,096 5/1961 Booth et al. 3,051,452 8/1962 Nobel 2594 WALTER A. SCHEEL, Primary Examiner.

I. M. BELL, Assistant Examiner.

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