US2328078A - Apparatus for drying wire screen cloth - Google Patents

Description

3 Sheets-Sheet l .,Iiil.;

H. C. KUGLER Filed oct. 11, 1959 APPARATUS FOR DRYING WIRE SCREEN CLOTH l l as Aug. 31, 1943.

4Aug. 31, 1943. H. c. KUGLER I 2,328,078

APPARATUS FOR DRYING WIRE SCREEN CLOTH y Filed Oct. l1, 1939 I 5 Sheets-Sheet 2 n Vm Aug. 31, 1943. H. c. KUGLER 2,328,078

AFPARATUS FOR DRYING WIRE SCREEN CLOTH s Sheets-sheet s Z 4 g z 105 79 Q1 @0 #fifa/Ways Patented Aug. 31, 1943 Y Harry C. Kugler, York, Pa., assignor to Superior Wire Cloth Company, Hungerford, Pa., a corporation of Pennsylvania Application October 11, 1939, Serial No. 298,884

1 Claim.

This invention relates to improvements in aD- paratus for drying wire screen cloth, and is particularly useful in connection with drying wire screen cloth coated with varnish or the like.

One object of this invention isv to provide improvements in drying wire screen cloth coated with varnish at a lower cost per square foot.

Another robject of this invention is to provide improvements in drying varnish on wire screen cloth under conditions which result in the varnish on wire screen cloth under conditions which result in the varnish being dried properly and speedily, independent of weather conditions.

Another object of this invention' is to provide improvements in drying varnish-coated wire screen cloth under conditions minimizing the danger `from explosion or fire from the volatile solvent employed in the varnish.

Another object of this invention is to provide improvements in drying varnish on wire screen cloth in an oven or drying chamber of less height than heretofore, whereby heavier grades of screen cloth can be dried.

Another object of this invention is to provide improvements in drying wire screen cloth whereby two widths of screen cloth can be dried at one time.

With the above and other 'objects in view, as will appear to those skilled in the art from the present disclosure, this invention includes all features in the said disclosure which are novel over the prior art.

In the accompanying drawings forming part of the present disclosure, in which one way of carrying out the invention is shown for illus- 4 tratlve pul'pOSe'SI Fig. 1 is a vertical sectional view of a double drying oven made in accordance with the present invention, with screen cloth varnishing and driving apparatus shown schematically;

Fig. 2 ls a vertical sectional view oi the oven on line 2-2 of Fig. 1; 1

Fig. 3 is a horizontal sectional view on line 3-3 of Fig. 1, with parts shown in elevation;

Fig. 4 is an enlarged horizontal sectional view on line 3 3 of Fig. 1, of the left-hand portion of Fig.` 3;`

Fig. 5 is a schematic diagram of electrical apparatus and connections for accomplishing automatic controloi the main apparatus for drying coated screen wire cloth;

Fig. 6 is an enlarged view in section of one of the varnish-applying means shown at the lower part of Fig. 1; A

Fig. 7 is an enlarged view in elevation,

parts in section, of the screen-cloth feed and reel apparatus schematically illustrated in'the lower left-hand portion of Fig. 1;

Fig. 8 is a left-hand elevation oi Fig. '7;

Fig. 9 is a fragmental sectional view on line 9-9 of Fig. 8; and

Fig. 10 is a fragmental sectional view on line lll-I0 of Fig. 7 of one of the friction slip-clutch mechanisms.

In the description and claims, the various parts and steps are identied by specific names for convenience, but they are intended to be as generic in their application as the prior art with permit. l

Referring to the drawings showing the particular form of the inventionchosen for illustration, 20 is an upstanding or vertical tower provided with a pair of upstanding ovens or drying-chambers 2l and 22 which are closed at the top except as regards the purging apparatus including the purging fan 23, and are open at the bottom, as illustrated in Fig. 1. The

outer walls and center portion of the tower are preferably heat-insulated to conserve heat. Thus, either or both of the drying-chambers may be used at the same time.

Each of the drying-chambers 2| and 22 has an air-delivery duct 24 located between the middle partition `25 of the tower and an inner wall 26 of each drying-chamber. Each `of the dryingchambers also has an opposite inner wall 21 spaced from one of the outer walls 28 of the tower to provide an air-return duct 29. Each of the inner walls ZB-and 21 is provided with airslots 30. Air-circulating means 3| provides for circulating or re-circulating heated air and combustion products through the drying-chambers 2| 'and 22. The air-circulating means 3| includes ducts 32, 33, 35, blower 36 and duct 31, which lead from the air-return ducts 29 past the nozzle ends of two burners 34 to the air-delivery ducts 24, the blower 36 serving to drive the air through the duct 31 and thence into the airdelivery ducts 24, from which delivery-ducts 24, the heated air passes through slots 30 in the upstanding inner walls 2G and across through the intervening spaces of the drying-chambers 2| i and 22 and out through similar slots 30 in the opposite inner walls 21 of the drying-chambers and thence into the air-return ducts 29.

Each burner 34 has a gas inlet nozzle 38 leading from a gas supply pipe 39 into the combustion chamber 40. 'Generally-annular air-inlet opening 4| provides for entrance of` auxiliary air to with the combustion chamber 40. Generally-annular air- inlet openings 42, 43, 44 and 45 provide for the entrance of auxiliary air directly into the tube 33 adjacent the ends of the combustion chambers 40 of the burners 34. The two annular plates 46 and 41 'are adjustably connected together and carried by the housing 48 andi each has an annular series of holes 49 so that the plates can be annularly adjusted relatively to one another to either align the holes of one plate with the holes of the other or offset them so as to block off the passage of air therethrough. Normally, the plates are so adjusted as to have the holes out of alignment and, therefore, in closed position, but if desired, they can be opened in greater or less degree, whereupon additional air will be drawn in through the annular passage 50 and past the end 5| of the casing 52 and along through the annular passage 53 and past the end 54 of the inner tube 33, to thus join with the air passing through the duct 35 to the blower 36. But since air and gas are introduced into the system in conjunction with the operation of burners 34, there is ordinarily no need of introducing additional air through the openings 49. A pilot 55 and an igniter 56 are arranged adjacent the burners 34 in a usual and well known asaaovs y s being Jdriven by a pinion 85 secured on a shaft 66 which at the other end carries a sprocket 81 driven by a 'sprocket chain 88 which is, in turn, driven by another sprocket 89 mounted on the out-put shaft of an adjustable drive 90, such for example as' a Reeves drive, driven by an electric motor 9|. The drive-roll 11 is mounted on a shaft 92 rotatably mounted in two levers 93 pivoted at 94 to the frame 95 of the apparatus, the upper ends of the levers 93 being actuated by springs 96 to swing the upper ends of the levers toward the drive-roll 16, to thus nor- Way forignitin g and maintaining ignited, the

burners 34, and re-,igniting them.

The purging fan 23 is connected by pipes 51 and 58 to the upper ends, respectively, of the drying-chambers 2| and 22, 'the fan 23 being drvenby an electric motor 59.

There is a separate reel-supply shaft, varnishing-station, screen-cloth drive and reel-up shaft for each of thedrying chambers 2| and 22, and as both of these are identical, only one will be described. vWhile, if desired, onlyY a single roll or single width of screen cloth can be passed through a. drying-chamber, in the preferred form of the invention illustrated in the drawings, two rolls of screen cloth 60 and 6|, respectively mounted on removably-mounted reel- shafts 62 and 63, pass two lengths of screen-cloth in sideby-side edge-to-edge relation over a group of three guide-rolls 64, then over another guide-roll 65, then down into a varnish-containing tank 66, around another guide-roll B1 and up out of the varnish 68, past an air-blast nozzle 69 which drives the excess liquid varnish off the screen cloth, whereupon the screen cloth passes upward intothe open lower end of the dryingchamber 2| up to the upper portion thereof and around the guide-roll 10, then down and around a lower guide-roll 1|, then again upward and around a guide-roll 12 and then down and around guide-rolls 13, 14 and 15, to two driverolls 16 and 11, and then around another guideroll 18, whereupon the two lengths of screen wire, respectively diverge to form two rolls 19 and 80 of wound-up screen cloth which are mounted on and wound up respectively by the reel-up shafts 8| and 82, which are preferably tapered to aid in removing the roll of wound-up screen cloth. Expressions such as side-by-side edge-to-edge, used in describing the relation of two lengths or widths of screen cloth, mean that the two edge portions which are nearest to each other are directed in a general direction toward one another. Such expressions as passing screen cloth through a drying-chamber includes passing screen cloth up into the bottom of a drying-chamber and down out of the bottom thereof, as in the appai ratus illustrated.

mally hold the drive-roll 11 in contact with driveroll 16 to grip the screen cloth passing there- -between to effectively aid in `driving the latter. The drive 90 provides for any desired Iadjustment in the speed of drive or travel of the screen cloth through the apparatus. c

Each reel-up shaft 8|, 82', has a longitudinal slot 91 to have the end of a length of screen cloth engaged therein, whereby each reel-up shaft can wind a` length of screen cloth into a roll. Each of the shafts`8| and 82 is driven by a gear 98 f coaxially therewith and which, in turn, is driven by a pinion 99 secured on ,a shaft |00 which has a slip-friction clutch |0| including a frictionplate |02 of any suitable material such, for example, as brass, keyed to the shaft |00 and fric- 'able slip-friction drive.

tionally engaged by one or more friction-disks |03 of suitable material such, for example, as fibre, in frictional engagement with a face of a sprocket-wheel |04 mounted on shaft |00 and driven by a sprocket chain |05 which, in turn, is driven from a sprocket |06 on the output gshaft of an adjustable drive |01 similar to the drive 90, and which is driven by an electric motor |08. A spring |09 acting between a hand-wheel ||0 and the sprocket |04 serves to press the latter firmly against the friction-disks |03 to .provide a suit- The hand-wheel ||0 is fixed on shaft |00 and provides for manual operation through the gears 99 and 98 'for rotation of the shafts 8| and 82 to reverse their directionof rotation from the reel-up direction', to release the end of the screen cloth engaged in each of the slots 91 preparatory to removal of the rolls of screen cloth 19 and 80 from the shafts 8| and 82. The reel- supply shafts 62 and 63 and the reel-up shafts 8| and 82 can be provided with usual removable hold-down means whereby the shafts can be released for lifting up to remove or place rollsof screen cloth as required. v By having the reel-supply shafts and reel-up shafts mountednear the i'loor as shown, heavy rolls of` is illustrated as being long enough to carry a fully 12" Width of screen cloth, although the width -of screen cloth actually wound thereon in Fig. 8

While the reel-up shaft 8| is much narrower. could be of full length like the shaft 82, it is only of suflicient length to accommodate a 36" width of screen cloth, the bearing-support in Fig. 8 supporting the right-hand end of the shaft 8| (behind shaft 82). In a similar manner, the reelsupply shaft 63 can be long enough to accommodate a '12" width and the shaft 62 can be short enough to only accommodate a 36 width. All of the guideand drive-rolls are of sufficient rotatably and slidably` length to support a full 72" width or two 36" widths or one 12"fw|dth andone 60" or less width, and so forth.

The adjustable drive 90 provides an infinitesimally-adlustable-speed variable-drive by means of which any desired speed of feed or travel of the screen cloth through the varnish-applying means and the drying-chambers can be provided. And the adjustable drive ||l`|` provides an inflnitesimally-adiustable-speed variable-drive by means of which the reel-upy shafts 8| and 32 can be driven at such speeds as will ensure their winding up the dry screen cloth fast enough to produce tightly wound properrolls of screen cloth, the two slip-friction clutches lill permitting the two shafts 8| and 82 to slip relatively to the drive so that the two shafts can acquire any necessary speeds and any variations of speed relatively to each other or to the drive, as may be necessary to produce two tightly properly rolled-up rolls of screen cloth. The screen cloth drive and reelup mechanisms can be controlled by a separate switch from that controlling the rest of the apparatus.

'I'he air-blast slot H2 of the air-blast nozzle 69 extends transversely entirely across where a 72 width of screen passes up out of the varnish 68 of the tank 55 so as to drive excess varnish from the screen cloth being coated or varnished. In order to give a downward wiping effect, the surface H3 of the bottom of the nozzle 59 forming the lower surface of the slot H2 makes approximately an angle shown in the drawing, of about 27 with the horizontal, whilethe under surface H4 of the angle iron H5 forming the upper surface of the slot H2 extends horizontally, the narrowest portion of the slot H2 being about an eighth of an inch. The degree of the angle of the surface H3 can be increased up to as much as about a 45 angle depending on various factors. 'I'hus with a suitably-large size varnishdipping tank and a suitably-larger fan to supply the air blast, a 45 angle could be used. Also, instead of using only one air-blast slot, two airblast slotsy could be used, one being located several inches such, for example, as six inches, above the lower one, the larger the degree of angle of the slot with the horizontal, the greater the wiping eil'ect on the cloth in assisting gravity in draining the excess varnish back into the tank. Any varnish films closing meshes of the screen cloth, which might escape the air-blast, will be opened by the cross currents of air between the air slots of opposite inner walls of the dryingchambers.

Closing of the main switch H5 supplies electric current from the main line wires H1 te the electric motor 59 which drives the purge fan 23, and also starts the timing relay H8 which can be set to close the contacts H8 after any desired interval such as for a period of from five to seven minutes. Upon the contacts H9 being closed, the magnetic contacter |20 is actuated to close the contacts |2| thus closing the circuit to the motor |22 of the blower '35 and actuating the electrically-actuated pilot 55 to supply a pilot flame in the pilot, and also actuating the electricallyactuated igniter 55 to light the pilot 55. When the thermostat |23 in one of the drying-chambers has cooled to a low enough temperature to close the thermostat switch |24 thereof, the magnetic contacter |25 is actuated to close the contacts |26 and thus open the gas-supply valve |21 to Supply Sas to the burners 34 which thus start in operation, and continue in operation until the thermostat |23 heats up to a degree sumcient to cause the thermostate switch |24 to open, whereupon the gas supply valve I 21v is closed, thus shutting of! the burners 34. During normal operation of the apparatus, both while the burners 34 are onand while they arel oil, the motor 53 continues to drive the purge fan 23, which latter has suillcient air-removing or exhausting capacity to Just remove or purge suillcient air and' shut off by the thermostat |23, the purge fan 23 continues to operate thus preventing the accumulation of inflammable vapors within` the drying chambers. By having the purge fan 23 continue to operate even when the feed of the screen cloth through the, apparatus is stopped, permits of allowing the screen cloth to remain in the drying chamber instead of `running an apron through, and saves expenses and loss of operating time. The operation of the purge fan 23 prevents the screen cloth from changing color from excessive action of heat. f

By means of the apparatus shown and described, air can be heated to a suitably high degree by the burners 34 and caused to travel transversely across the drying-chambers 2| and 22 from one set of slots 30 on one side of each chamber to a similar set of slots on the other side of each chamber, thus causing the -air to pass through the several layers of screen cloth which are passing up and down through the dry ing chambers, and the air as it passes through the` screen cloth picks up the volatile varnish solvent. The latter is carried out through the duct 32 and back through the flame produced by the burners 34 to thus eliminate the varnishsolvent vapors by burning them, thus accomplishing two important results, namely, reducing the risk of fire from the varnish vapors in the drying system and at the same time utilizing these vapors as fuel to aid in the production of heat to heat the air being recirculated through the drying-chambers. By means of the apparatus shown and described, a suitably high temperature of air can be maintained so uniformly throughout the heating chambers without endangering the scorching or damaging of the varnish, that the apparatus can be operated effectively in the most humid weather with apparently no harmful effect from the humidity. This appearsto be largely due to the fact that a very high average temperature can be maintained very uniformly throughout the drying chamber. Also this high average uniform temperature so greatly increases the speed of drying oi the screen cloth that it is not necessary to have the drying chambers as high as has heretofore been necessary.

The invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and

al changes coming within the meaning and e uivalency range ofthe appended claims are intended to be embraced therein.

I claim: l

Apparatus for drying wire screen cloth having a coating containing volatile solvent, comprising: an elongatedmpstanding drying chamber open at the bottom"and having upstanding opposite inner walls and two sets of air-circulation openings distributed substantially throughout the circulating means including duct means and an air-pump, said air-circulating means leading from one of said sets of openings to the other of said sets of openings, and said air-pump being for recirculating air through said air-circulating means and drying chamber; name-heating means exterior of said drying chamber and adapted to produce a ame in said duct mer-.ns adapted to heat the air and burn solvent in s iid air passing therethrough, to heat said dryng chamber and screen cloth therein; means for introducing air and fuel toA said heating means; and means for discharging from the drying apparatus, an amount of said air and combustion products approximately equal to the amount of air and combustion products introduced into the aircirculating means adjacent said ame.

HARRY C. KUGLER.

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