US 3218048 A
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Description (OCR text may contain errors)
16, 1965 s. M. SMITH, JR.. ETAL 3,218,048
PACKING FOR FRACTIONATING COLUMN AND THE LIKE Filed Sept. 14, 1960 2 Sheets-Sheet l BWMQ/M',
Nov. 16, 1965 s. M. SMITH, JR, ETAL 3,218,048
PACKING FOR FRACTIONATING COLUMN AND THE LIKE Filed Sept. 14, 1960 2 Sheets-Sheet 2 I]: l 1 I I I I & I I i W i: i 1': 1; 1 I] I l I 1 I l 1 I} i; I I I: I :l l \J J United States Patent 3,218,048 PACKING FOR FRACTIONATING COLUMN AND THE LIKE Stanton M. Smith, In, West Orange, and Ralf L. Hartwell, Cranford, N.J., assignors to General Cable Corporation, a corporation of New Jersey Filed Sept. 14, 1960, Ser. No. 56,042 2 Claims. (Cl. 26194) This is a continuation-in-part of application Serial Number 576,231, filed April 3, 1956, now abandoned.
This invention relates to packing material which is operative to effect contact between liquid and vapor or gas in fractionating columns, scrubbers, and the like, and more particularly to a gas and liquid contact apparatus embodying fabric layers for controlling the flow and distribution of the liquid and gases.
An object of the invention is to provide a packing material of the above type having novel and improved characteristics.
Another object is to provide a packing material in which the liquids and gases are caused to repeatedly divide and recombine in their path through the contact apparatus.
Other objects and advantages will be apparent as the nature of the invention is more fully disclosed.
In accordance with the present invention the material is fabricated from strands composed of a plurality of individual continuous filaments composed of non-wicking material which are grouped together in parallel and substantially untwisted relationship to form a strand wherein the filaments form surface channels and capillary interfilament spaces along which the liquid flows downwardly in its path through the contact zone.
These strands are woven or knitted, or otherwise fabricated, to form a fabric layer having a mesh of such size that the interstrand openings are not filmed over by the liquid, but remain open for the passage of gases while the liquid flows along the surfaces of the strands and through the capillary passages between the strands such fabric being herein referred to for convenience as having a non-filming mesh.
The nature of the invention will be better understood by referring to the following description taken in connection with the accompanying drawings in which specific embodiments thereof have been set forth for purposes of illustration.
In the drawings:
FIG. 1 is a perspective view of a packing unit embodying the invention;
FIG. 2 is a broken side elevation of a packing unit in place within a column, the column being shown in longitudinal section;
FIG. 3 is a plan view of a flattened tubular knit sleeve of capillary strand material from which the packing unit is produced, said view including a magnified showing of a portion of the knitted capillary strand material;
FIG. 4 is a plan view of superposed transversely and angularly corrugated or crimped plies of the knitted capillary strand material of FIG. 1, ready to be rolled lengthwise upon themselves into a cylindrical packing unit ac cording to this invention; and
FIG. 5 is a longitudinal sectional view, taken on the line 5-5 of FIG. 4, and including a magnified showing of a portion of the superposed corrugated or crimped plies of the knitted capillary strand material.
Referring to the drawings more in detail:
The capillary strand is shown as composed of a group of several continuous filaments composed of wire or of a synthetic material which is non-absorbent and non-wicking and is substantially impervious to the liquids to be treated. A group of more than two and preferably ten or twelve wire filaments having a diameter of the order of .0045 is usually preferred. By continuous filaments is meant long filaments which are capable of being retained in untwisted condition as distinguished from short staple fibers which must be spun to form a yarn. The filaments are bunched in parallel and substantially untwisted condition to form a strand wherein the filaments are held in contact or so closely spaced that liquid flows along the surface channels formed by the filaments and in the interfilament spaces by capillary action.
The capillary strand 10 thus provided is knitted, woven or otherwise fabricated into a flat fabric of suitable width and length. Preferably, the capillary strand 10 is knitted into a tubular sleeve 11 of suitable loop or mesh size, which sleeve is then flattened to provide a mesh body of required width and length (FIG. 3). The fabric is made of open non-filming mesh wherein the various openings in the knitted loops or between strands in the woven fabric form cells of a size such that the liquid being treated flows along the strands without filming over or closing the openings in the mesh. The interlinked knitted loops of the mesh body serve to hold the wires or filaments of the strand 10 together in capillary relationship, without necessity for use of applied gimping or other additional holding means for such purpose.
The flattened mesh body 11 formed from the capillary strand 10 is run through corrugating rolls, so as to form therein successive corrugations or crimps 12 extending obliquely across the width thereof. At least two such corrugated or crimped mesh bodies are superposed in such manner that the corrugations or crimps of one cross those of the other in contacting but non-nesting relation (FIGv 4), and so that the troughs of the corrugations or crimps in the contiguous faces of the superposed mesh bodies provide continuous passageways 13 of such dimensions and form that they are not sealed by liquid.
The superposed corrugated or crimped mesh bodies are rolled endwise upon themselves, whereby to form a packing unit P of cylindrical shape, and of selected diametric size, preferably but not necessarily, corresponding to the internal diameter of a column to be served thereby (FIG. 1). The cylindrical contact unit thus formed provides a structure having a multiplicity of uniformly disposed interconnecting passages. In use, the thus formed packing material P is inserted into the interior of a column C (FIG. 2). If the column is long, a plurality of packing units P can be stacked within the column.
In operation of the column packed with the packing units of this invention, the vapor or gas, introduced into the column below the packing, flows into and upwardly through the spiral passageways 13 formed by contacting corrugations or crimps 12 of the mesh bodies and through the cells comprising the packing material. Since said passageways 13 are bounded by the open structure of interknit loops which form the cells of the mesh bodies, the vapor or gas can freely flow through the loop openings from one passageway to the next while at the same time the irregular or somewhat roughened surfaces of the mesh bodies promotes turbulence in the vapor or gas streams.
The liquid, introduced into the column above the packing, as it flows downwardly therethrough along the capillary strands, is continuously divided and distributed at the points of intersection of the knitted or otherwise interlaced capillary strands. The knitted structure of the mesh bodies provides a substantially regular pattern of crossing or intersecting engagement of the capillary strands where the loops thereof interlace, and also there is additional contact of the capillary strands where the corrugations or crimps of superimposed contacting contiguous mesh bodies abut and engage one another. At these points of capillary strand engagement, liquid 3 streams that are flowing along the capillary strands are caused to meet and redivide, substantially uniformly throughout the mass of the packing unit or units, thus promoting thorough mixing of the liqiud.
It will be obvious that this thorough mixing of the vapor or gas and the thorough mixing of the liquid, in the presence of one with the other, assures highly effective mutual contacting of said vapor or gas and liquid phases. Due to the continual redivision and mixing of both the vapor or gas and the liquid phases channeling of either phase is avoided.
Condensation of a vapor phase on the column wall, or deposit of liquid thereon by other causes, might produce an amount of liquid which, if allowed to flow down the column wall, would result in serious detrimental prevention of proper contacting of the vapor with the liquid phase. This is avoided however, by so sizing the capillary packing units of this invention that the same will make resilient contact with the column wall by abutment of the high points of external corrugations or crimps 12 upon the surface of the column wall. At such points of contacting abutment, the capillary nature of the packing forming strands effects removal of the liquid or vapor condensation from the column wall, and the union of this liquid with the liquid phase flowing along the capillary strands.
Inasmuch as changes may be made in the form of the packing material disclosed by the drawings and the above description, as well as in the fabric from which the same is made, without departing from the spirit and principles of this invention, it will be understood that the invention is not intended to be limited except as required by the scope of the appended claims.
What is claimed is:
1. Packing for vapor or gas and liquid contact columns, comprising a plurality of superposed contacting layers of a fabric having mesh forming openings of a size such that they are not filmed over by the liquid being treated, said fabric being composed of capillary strands consisting of a plurality of continuous filaments of a material which is non-absorbent, non-Wicking and impervious to the liquid being treated, the filaments in said strands lying parallel and being substantially untwisted to form a group thereof wherein adjacent filaments are so closely spaced that liquid flows along the surfaces of the filaments and in the inter-filament spaces due to capillary action, contiguous layers of the fabric being in contact to form a body having uniformly disposed intercommunicating cells through which the vapor or gas can freely flow in con 4 tact with counterflowing films of liquid flowing downwardly on the capillary strands, with a consequent repeated subdivision and recombination of both vapor or gas and the liquid streams passing through the column.
2. Packing for vapor or gas and liquid contact apparatus, comprising a plurality of superposed contacting layers of transversely obliquely corrugated flattened sleeves of tubular knit open mesh fabric knitted from capillary strand material formed by a gathering of time continuous solid longitudinally extending, filaments bunched together in substantially parallel and substantially non-twisted relation, and closely enough so that spaces therebetwcen will seal with the liquid, said superposed layers being so relatively disposed that the corrugations of contiguous layers cross one another in non-nesting but contacting relation, the thus related superposed layers being rolled upon themselves to form a convolute cylindrical body structure provided with uniformly disposed intercomniunicating cells between which the vapor or gas can freely flow throughout its mass, said body structure being adapted to be positioned in and across a column in axially aligned relation thereto, whereby to provide contact between a vapor or gas traversing the cells and counterfiowing films of the liquid on the capillary strand material, with consequent repeated subdivision and recombination of both the vapor or gas and liquid streams passing through the column, and said body structure being radially resilient so as to maintain contact with the wall surfaces of the column.
References Cited by the Examiner UNITED STATES PATENTS 2,388,933 11/1945 Pearson 261-407 2,470,652 5/1949 Scofield 261-94 2,615,699 10/1958 Dixon. 2,940,168 6/1960 Monroe 26l95 X FOREIGN PATENTS 1,043,959 6/1953 France.
OTHER REFERENCES Goodloe Packed Laboratory Columns, Bulletin of the Packed Column Corp., received in US. Patent Office Dec. 12, 1955, 4 pp.
HARRY B. THORNTON, Primary Examiner.
HERBERT L. MARTIN, Examiner.