US2669031A - Apparatus for drying a liquid coating on an elongated product - Google Patents

Description

APPARATUS FOR DRYING A LIQUID COATING ON AN ELONGATED PRODUCT 3 Sheets-Sheet 1 Original Filed Feb. 6, 1948 INVENTORS C. R. OM55 an GEORGELBL 0r A M, w 6,

c. R. CHASE ET AL 2,669,031 APPARATUS FOR DRYING A LIQUID COATING ON AN ELONGATED PRODUCT Original Filed Feb. 6, 1948 5 Sheets-Sheet 2 Feb. 16, 1954 I l /2 a 2b 42 /Ec INVENTORS C. R. CHASE and GEORGEL- BL/ss,

Feb. 16, 1954 Q CHASE r AL 2,669,031

APPARATUS FOR DRYING A.LIQUID COATING ON AN EILONGATED PRODUCT Original Filed Feb. 6, 1948 3 Sheets-Sheet 5 INVENTORS 33 3a C/R'CHASE and GEORGE L. 8/. /ss,

group of take-up blocks I3 driven by conventional means indicated diagrammatically at I4. If the apparatus be installed in conjunction with continuous patenting apparatus, it will be disposed beyond the last acid pickling tank I5 and the warm-water rinse tank I6 of the latter. In any event, a plurality of wire strands I! are drawn through the several pieces of apparatus successively in the direction indicated by the.

together and is adapted to contain a lime bath,

the surface of which is indicated at 2|. Holddown or sinker sheaves 22 are rotatable on a shaft 23 extending transversely of the tub and up o i n er brask h 2. depending m the sides thereof. The sheaves 22 have v grooves spaced axially therealong for receiving individualiy the strands entering the bath after passing over the guide roller I8 at the right-hand end thereof and maintaining them inspaced relation as they are drawn up from the bath through the oven I2. As clearly shown in Figure '1, the sheaves 22 have their greater portion immersed inthe hath. I

i In order to maintain the bath of a substantially' uniform character and prevent the settling out of the solid phase, we'maintain a substantially constant circulation thereof along a predetermined path. To this end, a darn or bafile 25 i's dispos ed transversely of the tub adjacent the sheaves 22. The dam extends upwardly from a floor'or deck 2% in the left-hand end of the tub spaced a short distance above the bottom thereof. 'The dam is of such height that its crestis an'i'nch or so below the surface'of the bath. "A' centrifugalpump 2i driven' by motor 28 has its inlet connected by'a pipe 29' including a valve'3ii to the spacebetwee'n the dam 25 and the left-hand end of the tubyabove the deck 26; The outlet from thepump is connected by a pipe SI including a Valve 321d a header 33 extending across'the left-hand end of the tub below the deck 2 and provided at'its ends with nozzles 33 adapted to deliver jets longitudinally of the tub and close to the bottom thereof, as indicated at 34.

"Whenthe pump is in operation, it induces a circulation of'the lime in the tub, as indicated b the dotted arrows, i. e., from left to right along the"'bottem of the tub, upwardly at the right-hand end thereof and from right to left adjacent the surface of the bath, thence downwardly around the sheaves 22,upwar'dly between them and the dam 25 and over the crest of the latter to the outlet pipe 29. It will be apparent that the jets 34 create considerable agitation of the bath as it circulates throughfthe right-hand end thereof. The portion of the bath between the sheaves 22 and dam 25 by comparison is relatively quiescent. By reason of the circulation and'agitation, all parts 'of the bath have substantially the same amount of suspended solids, in this case calcium hydroxide, the liquid being water. As a result, the wire strands passing around the sheaves 22 and emergingsubstantially vertically from the bath acquire an adherent film of lime which is uniform among the several strands and from point to point along each strand.

' The oven I2 (see Figures 4 through '7), through which the strands ascend on emerging from the lime bath, is an elongated box-like chamber disposed vertically, the walls of which are composed of suitable insulating or refractory lining 12 laid up in a binding composed of metal sheathing plates I2 secured to a frame of structural members" I2 The bottom of the oven has an entrance slot 35 extending across the width thereof. The top of the oven has a similar exit slot 36. Tubular burners 31 extend across the Width of the oven at the bottom thereof, one on each side of the slot 35. A pilot burner 38 with 'a'Spark-gap igniter extends through one side wall of the oven at a level slightly above the burners 31. The burners are connected to any convenient source of fuel gas through inspirator tubes and are provided with suitable control valves. H

It will be apparent that the burners 31 heat the interior of the oven effectively by radiation and convection, the combustion gases passing upwardly through the oven and out through the slot 36 maintaining a natural draft of secondary air through the inlet slot 35. This draft iscontrolled by damper plates 39 "(see Figure 7) hinged to the top of the oven and having their free'edges partially overlying the slot 36. One of the dampe'rs is composed of two lapped sections adjustably connected by bolts passing through slots therein andprovided'with wing nuts. This permits adjustment of the extent to which the free edge of the damper overlies the" outlet slot. The hinged mounting of the'dampers permits them to swing upwardly to provide the necessary clearance in case they are engaged by a splice joining successive lengths or a Wire strand.

Before lighting the burners, the oven is purged of air by an exhaust fan 40 mounted on brackets 4| secured to one side of the oven; The inlet of the fan is connected'to an outlet 42 'in'the oven wall and the fan is driven by'a motor 43 mounted 'on'brackets 4|.

The oven ismounted for traveling movement from a position over the tub II, as shown in Figure l, to an out-of-the-way position laterally spaced from the tub, as indicated in chainlin'es in Figure 1. The oven is preferablysuspended from beams 44 by brackets'45 secured thereto and to the frame members of the oven binding." The beams 44 are carried by'hanger rods 45 depending from trolleys 41'. These trolleys are adapted to travel along spaced rails '45. The rails may be supported in any convenient manner. In Figure 1 they are illustrated as secured to cantilever beams 49 extending laterall from a supporting framework 50 of structural members. If the roof trusses of thebuilding in which the apparatus is installed are of sufficient capacity, however, it is usually more convenient to suspend the trolley beams directly therefrom. The mounting of the oven I2 for lateral movement to an out-of-theway position facilitates threading'the wire strands through the apparatus" and gives ready access to the tub II for removal of the sheaves 22 when necessary. In order'to permit the oven to clear the wire strands when properly threaded, one side wall is in the form of a hinged door 5!, as shown in Figure 6. The entrance and exit slots 35'and 36 extend through the 'edgeof the bottom and 1 top of the oven, respectively, on the side on which the door is mounted. I

The oven l2 may be moved from one position to another by manual effort directly applied.

For more convenient operation, however, an actuating chain 52 is provided having its ends secured to a gusset 53 fastened to one of the beams '44 and trained around spaced sprockets 54 l2 and are adapted to receive the wire strands emerging therefrom and support them as they travel downwardly toward the take-up blocks IS. The sheaves are journaled for rotationon a shaft 58 which may be supported in any desired manner, e. g., on the beams 49, as shown in Figure 1, or by hangers 59 depending from the roof trusses, as shown in Figures 4 and 5.

In using the apparatus described above, a plurality of wire strands I! are introduced into the lime bath 2| in tub II. Total immersion is effected by guiding the strands into the bath over and around the supporting roller I8 at the entrance thereof and under and around the holddown or sinker sheaves 22. As shown in Figure 1, the angle made by the entering strands drying and there is no contact with the wire be- I tween final emergence from the coating bath and with the surface of the bath is less than 45. The

bath is maintained at a temperature of from 180 to 220 F. by any convenient heating means, such as immersed steam pipes and preferably has a solids content of from 8 to 15%. In case the wire to be coated is delivered directly from acontinuous patenting apparatus, the cold-water wash tank Ii! is preferably supplied withwater at a temperature of from 50 to 65 F., in order to improve the adherence of the lime to the wire as it passes through and out of the bath.

After passing around sheaves 22, the wires travel upwardly from the bath in a vertical path through the drying oven l2. By drawing the wire strands vertically from the bath in a portion thereof which is relatively quiescent, i. e., the space between sheaves 22 and the dam 25, the adherence of a film of maximum thickness for the existing concentration of th bath is assured. Since the bath is of substantially uniform character throughout, there is no tendency for the film to be partly washed off or diluted as the wire emerges from the path. The reduced velocity of the bath adjacent the point of emergence of the wire strands, furthermore, tends to prevent the film' disposed on the wires from being washed therefrom. As the wires ascend vertically from the bath, any excess lime adhering thereto runs downwardly along the wires by gravity, thus tending to render the density of the film uniform at all points along each wire.

The film adhering to the wire strands is dried and baked as they pass upwardly through the oven H2. The oven is preferably maintained at about 400 F. although this temperature may be varied considerably. An oven operated at this temperature is capable of satisfactorily drying the lime coating on wire passing therethrough at speeds of about 100 ft. per minute. It will be observed that the strands are maintained in spaced-apart relation to each other and free I from contact with an guiding or supporting means during their ascent through the oven.

The strands are stretched between the sinker sheaves 22 and the guiding sheaves 51 so that the fihn of lime adhering to the wires as they pass around the former and upwardly out of the bath is fully dried and baked on by the time the latter is engaged. In fact, the drying and baking are effected to an extent such that the bending of the wires around. the sheaves 51 does not cause any noticeable flaking off of the coating. It will be apparent from the foregoing that the invention herein disclosed is characterized by numerous advantages over the prior practice of coating wire with lime. In the first place, the

invention makes it possible to apply a lime coat ing of much greater uniformity than is obtainable with the method used heretofore. Each point of each wire strand is subjected to practically identical conditions of lime pick-up and complete drying of the adherent film. As a result, bare or uncoated spots on the wire strands are wholly eliminated. By reason of the uniform coating, the subsequent drawing of the wire may be carried out at a higher rate than heretofore with less die wear. In fact, the life of the dies is increased from 25% to 50%. At the same time the resulting product is superior in quality and finish to that made of wire limed by the batch process. This results from the fact that the absence of bare spots prevents bright spots on the finished wire which are subject to scratching. The coated wire is delivered directly from the sheaves above the oven to the take-up blocks, thus eliminating the possibility of abrasion by contact with intermediate guide rollers.

The advantage of the traveling mounting of the drying oven in facilitating threading and giving ready access to the sinker sheaves has already been mentioned. The construction and arrangement of the lime tub and the continuous circulation of the bath contribute in an obvious manner to the application of a highly uniform coating to the wire strands traversing it. The tub and drying oven, furthermore, are of simple construction so that their initial cost is not large and the maintenance thereof almost negligible.

Although we have illustrated and described but a preferred embodiment of the invention, it will be recognized that changes in the arrangement and details of construction and operation may be made without departure from the spirit of the invention or the scope of the appended claims.

We claim:

1. Apparatus for treating wire or the like comprising an elongated drying oven disposed vertically and having transverse entrance and exit slots in its bottom and top, respectively, and an opening in one side from top to bottom communicating with said slots and aifording clearance between the wire and oven on sidewise movement of the latter, brackets extending from the sides adjacent that having said opening and overhead trolleys secured'to said brackets supporting said oven for sidewise movement along the line of said slots.

2. In a wire-treating apparatus including vertically spaced sheaves between which the wire travels in a vertical path, the combination therewith of a vertically elongated box-like oven between said sheaves enclosing a portion of said path, said oven having transverse slots in its amgm bottom and: top fiorupasssgethe wire. both aaid shots exteniiing thmugh one. side at? the eaten, and means suspending the (men fmm abov. for travelingmovemnt, along, the line at said slots to an out-of-the-wam position laterally; or said path, said one side at the oven having" means adapted t6 clean the wire on such mbvmenfi.

3. Apparatus as'defirxed by claim Zicharacterized by said suspending rriealnsi including spaced ra ils mountd above the oven and tioHeys traveling thereon 50" which the oven is sgcure'd. N y V 4. Apparatus as defined by ql-aim 3 characteri'z ed by an ez idlesschain hayinga mm substantially parallel to said l ail'safid" secured a1; oge point; to said fiven, anig means for causir'ig "travel 6% the chair; whefebyt'p mdve'thp 'overi along said rails. .7 v s a 7..

8 withsaid slots nd a. @093; nus-mal s l six s th opemng.

"6. Apnamms as defin d, x; elaim 2.- Qhamct izem by a. dampen efiestim paxti glly t0 lose th slot in the top. oi. the own.

Apparatus as defined by claim. 2; ehalzashexby. an exhaust fan mounted on one; side. of the. even and communicating with the, interior thereofi.

' CHARLES; R. (ll-M515.

GEORGEL. Buss.

Rem-m gs Gitafl, n 2 9 filfi. 92 2111 Damn UNITED STAT-Es 142; 129 zgejasma

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