US2770212A

US2770212A - Continuous flow spraying system

Info

Publication number: US2770212A
Application number: US278553A
Authority: US
Inventors: Israel H Marantz
Original assignee: Columbia Cable and Electric Corp
Current assignee: Columbia Cable and Electric Corp
Priority date: 1952-03-26
Filing date: 1952-03-26
Publication date: 1956-11-13
Anticipated expiration: 1973-11-13

Description

N0V- 13, 1956 l. H. MARANTZ CONTINUOUS FLOW SPRAYING SYSTEM.

2 Sheets-Sheet 1 Filed March 26. 1952 VAN@ Nov. 13, 1956 1. H, MARANTZ 2,770,212

CONTINUOUS FLOW SPRAYING SYSTEM Filed March 26. 1952 2 Shee'cs-Shee"v 2 INVENTOR ATTOR EYS nited States Patent M CONTINUOUS FLOW SPRA'YING SYSTEM Israel H. Marantz, Forest Hills, N. Y., assigner to Columbia Cable & Electric Corporation, a corporation of New York Application March 26, 1952, Serial No. 278,553

Claims. (Cl. 11S-51) As conducive to an understanding of the invention, it is noted that when metal spray pistols are utilized to apply a metal coating to an object, only a portion of the sprayed metal powder may strike the object and the remaining or excess powder will fall to the bottom of the spraying chamber. ln order to reduce the cost of operation, such excess powder is collected and as the original size of the particles forming the powder change by reason of the spraying operation, such excess powder is then separated into its various component grades inasmuch as the spray pistol must be set for a given particle size. The separated particles are thence poured into hoppers associated with each of the spray pistols.

The above operation is extremely time-consuming inasmuch as it necessitates stoppage of the spraying operation for removal of the excess powder and then such powder must be taken to special units for processingk after which the separated powder must be brought back to the supply hoppers of the spray guns.

It is accordingly among the objects of the invention to provide a continuous ow spray system which is highly eicient in operation and dispenses with the need for stoppage of the spraying operation for collection of excess powder, which system automatically removes the excess powder from the spraying chamber, separates such powder into a plurality of particle sizes suitable for use in a spray pistol, discarding particles which are too large or too small, and thence feeds such separated particles to the spray pistols, such operations being performed dependably and reliably without the need for any supervision.

Another object of the invention is to provide a suction nozzle into which heated particles may be sprayed without likelihood of such particles hitting the walls of the nozzle with resultant congealing and clogging of such nozzle.

Another object is to provide a distributor for powder spray pistols whereby controlled amounts of powder may be fed to associated spray pistols without need for complicated adjustment and with a minimum of supervision.

According to the invention from its broader aspect, the continuous flow system comprises a spraying chamber which has a plurality of spray pistols therein fed from a distributor which in turn is charged by powder fed from a suitable powder separator. Suction means are associated with the chamber to draw excess'powder therefrom into a second separator which splits the particles drawn therein into two sizes, the larger and heavier of such j particles being discharged from such second separator onto a vibratory sifting means which discharges coarse particles and selects the ner particles for discharge into the rst separator, the latter in turn discharging through suitable feeding units onto the distributor.

In the accompanying drawings in which are shown one or more of various possible embodiments of the several features of the invention,

Fig. 1 is a diagrammatic view of the continuous flow 4spraying system,

ICC

Fig. 2 is a view taken along line 2-2 of Fig. 1,

Fig. 3 is a perspective view of the distributor with a portion brokenaway, and

Fig'. 4 is a longitudinal sectional view of the suction nozzle.

Referring now to the drawings, as shown in Fig. l, the continuous flow spraying system, desirably comprises a spraying unit through which metal tubes 11 may be advanced such as in the manner shown and described in copending patent application Serial No. 86,532, now Patent No. 2,683,436, dated July 13, 1954.

The spraying unit desirably comprises a substantially upright rectangular cabinet 12 having suitable openings 13 in the opposed walls 14 thereof as shown in Fig. 2 through which the metal tubes may be advanced. Positioned in the cabinet 12 are suitable metal spraying means which desirably comprises a plurality of conventional metal spray pistols 15, which, though they may be of any suitable type, illustratively are of the type known in the art as the Schori pistol. The pistols 15 are designed to spray 1a non-ferrous metal coating such as zinc on the tubes as they are advanced through the cabinet 12.

Although the spray pistols 15 may be positioned in the cabinet 12 in any suitable manner, a particularly desirable arrangement is shown in Figs. 1 and 2. In the arrangement shown, three pistols 15 are provided, designated 15a, 15b and 15C, which are radially arranged around the tube 11 and'spaced substantially 120 degrees apart with the nozzles of each pistol directed toward the line of movement ofthe tube 11. The pistol 15a is desirably directed upwardly and the pistols 15b and 15e` are desirably directed obliquely downward toward the walls 16 and 17 of the cabinet 12 respectively. Preferably the pistols 15 are arranged in different vertical planes as shown in Fig. 2 so that the zinc sprayed therefrom will not strike an opposed pistol.

The cabinet 12 which is substantially closed, desirably has a funnel shaped top wall 19 with an outlet 18 therein vertically aligned with the spray pistol 15a and has a 'discharge opening 20 at the bottom thereof through which waste powder may fall to be collected in a suitable container 30. Each of the walls 16, 17 of the cabinet 12 mounts an exhaust nozzle 21 which are longitudinally aligned with the spray pistols 15b and 15e` respectively so that the spray from said pistols will be directed into the mouth 23 of the associated nozzle.

As shown in Fig. 4, the nozzle 21 desirably comprises `a substantially cylindrical outer casing 24, which preferably has an outwardly flaring mouth 25. Positioned in Vrim 35 aixed as by rivets 36 to the rim 37 of the mouth 25 so as to provide an airtight seal at the mouth 23 of the nozzle 21. The casing 24 desirably has a baffle plate 38 affixed to the end wall 33 thereof and positioned between the cylindrical portion 28 of funnel 26 and an air inlet port 39 in the outer casing 24 so that air forced into said port 39 from a suitable source of compressed air (not shown) will be deected away from the opposed portion of funnel 26 to completely fill the chamber 41 formed between the outer casing 24 and the inner casing or funnel 26.

Each of the spray pistols 15 has a suction line'44 connected thereto through which powder may be fed to the pistol. Each'of the Ysuction lines 44 is connected to an associated outlet port 45 in a powder distributor V46 shown in Figs. l and 3. The distributor 46 desirably comprises an elongated, substantially rectangular `block of any suitable rigid Nmaterial suchas metal. Theblo'ck has a plurality of vertical bores 48 therethrough, Yspaced therealong, each of said .bores desirably having 'a' funnel lshaped mouth 49 in the top surface 50 of the block 46 of diameter substantially equal to the width of the'block with the rims 51 of adjacent mouths being in'juxtaposition.

Extending transversely through the block V46 are a plurality of bores 52 associated respectively with each' of the bores 48 and passing therethrough. The ends of bores 52 Ain the side wall 53 of the'block46 define the outlet ports 45and each Vof the other. en'ds of bores `52 in side wall '54 has a valve 55 therein'tocontrol the how of air into the associated bore `5,2. 'Positioned directly beneath the lower ends of the vertical bores 48 inthe distributor 46 isy a suction collector 57 which is desirably connected by branch suction lines 58 and 59l to a main suction line '61.

Each'of the exhaust nozzles 2,1'also 'desirably has a branch suction line 59 connected theretothrough which the powder particles from the vspray pistols may be conveyed. One end of line' 59 is connected to main suction line 61 andthe other end 62 of said line 59 is desirably aixed inthe inturned `ilange`31 of the associated nozzle 21. `In addition, 'the outlet'lS of top wall 19 of the cabinet 12 isdesirably connected by a 'branchsuction line 63 tornain 'suctionline 6,1. n Y y The main suction line 61 desirably leads into an inlet portw 60 inthe top portion of a plenum collector 64, which as it is conventional in construction, will only be described to the extent necessary for a clear understanding of the invention.

As shown in Fig. 1, the collector 6 4 desirably comprises a substantially cylindrical casing 65 having a funnel shaped bottom wan s6 with a cylindrical Outlet 67 having" a suitable valve 68 to control the dicharge of particles from thecollector. Positioned in the casing 65 is a cylindrical lbafle'member 71 which desirably has an inclined flange 72 at the upperA edge thereof affixed tothe wall ofithey casing above the port 60. Thus, all the particles sucked into Ythe collector by suction applied to outletport 78 lby'a'fsuitable suction fan 79 will initially be diverted downwardly and only the lighter particles will rise through the borel 75 of the baffle member and past vthe upper and

lower edges

76 and 77 thereof to be drawn through ythe outlet port 78 of fthe collector-64,.

, kThe suction fan 79 which may be of conventional de- 'sig n,l'has itsnlet line 81 connected to port 78 of collector 64 and its outlet line 82 connected to the inlet port 83 of a 'conventional cyclone collector 84'whlch` also Yis conventional Vin construction. The collector 84 desirably hasxan outlet 85` at, the top thereof through which very line particles which may be of micron size, may be forced, to ,beA dissipated into the atmosphere or collected by means of a conventional wet collector or a bag type collector `(neither of whichlis shown). The collector 84 also has an outlet 86 at the bottom thereof, having a'valve 87 therein to control the discharge of particles into a hopper`88. U,

A Positioned beneath theoutlet 67 of the plenum collector 64 to receive, the particles discharged therefrom, 1s an inclined screen` 9'1umounted on suitable supports 92 so1 that it may be vibrated by any suitable vibrator-y means 93. Y VThe perforations 90 in the screen 91 are of such dimensions that onlyparticles'pof less than a given; size may 1521.878 therethrough, the largereparticlesfrolling down the n l A inclined screen 91 to be dlscharged into a suitable receptacle 89 positioned beneath thelower` or discharge edge 80'of said screen. The particles passingthrjoughthe `screen91 are discharged upon a suitable conveyor belt 94 which is' driven in conventionalV manner in acounterclockwise direction as shown. The conveyor belt 94 positioned so as to 'discharge the particles thereon 4into the inlet or mouth 96 of Va conventional air type separator 97. The separator 97 is designed to separate the particles therein into two sizes, one of which is discharged through an outlet 98 into a hopper 99 and the other of which is discharged through anoutlet 101 into a hopper,

102. Associated with the hopper 99 isa feed funnel 103 which desirably has avibrator104rnounted'thereon to prevent Yclogging of the particles therein.' Positioned beneath funnel 103 isan inclined feed table'lmounted on suitable supports 105 so that it maybe vibratedby any suitable vibratory means 106. y.lhus the particles discharged on table from funnel 103 will be distributed over the entire surface of such table by reason of the vibration thereof and the particles will gradually move down the inclined table 100 to drop olf the lower or discharge edge 107 thereof into the distributor 46 positioned therebeneath. y l

shown :in Fig. 1,suitable'heating means `108 lwhich maybe 'infrared heaters, are positionedover the'table 100 toldry theparticles thereon. In addition, V'electromagl'netic'means' 109 are positioned adjacent the discharge end 107of table 100 to remove iron or steel vparticles 'from' the zinc `powder which maykbecome mixedithere- .with by reason of chipping of such iron or steel particles from 'the metal tubes being sprayed. v ,e

Itfis ofcourseto be understood that a feeder unit 103 `and"100, `a`distributor 46'and a 'spray unit 12 similar to those'a's'sociatedwith hopper`99 could also bev'ass'ocia'ted with each of the hoppersV 8S and 102'so that the three sizes`of` particles in the respective hoppers could be utilized ineach spray unit and the spray pistols in each unit wold be adjusted to accommodate the particular particle 4size provided.

Operation A l'nthe operation of the spraying system above described, un'graded zinc powder which is generally corn- -posed of particles of two sizes designated for illustration A and B, the former being larger than the latter, is

poured into the mouth 96 of the air type separator 97.

This separator will separate theungraded particles into Vsize A and B particles, the former being discharged through outlet 98 into hopper 99 and the latter through outlet 101 into hopper 102.k

As theoperation of the system is identical withrrespect to the particles in hoppers 88, 99 and 102, only theA portion of the systemassociated with hopper'99 will 'bei described in detail.

The A type particles in hopper 99 will ow intolfunnel 103 and thence onto feed table 100, the vibrator 104 preventing clogging of such particles in said funnel. As the 'feed'. table 100 is vibrated by vibrator 1*'06, the

'particles thereon will bey distributed over the entire surface of` such tableand will flow down the latt'er olf the discharge end'107 thereof onto the top surface 'of distributor'block'46- By reason of the infrared heaters 108, the particles on table 100 willbe dried and the e'lectromagnet`109 will remove *magneticV metal impurities of'iro'n orsteel from the non-ferrouszinc particles.

' Ina'sr'nuch as the funnel shaped mouths 49 of the`bores '48in'dis`tribut'or'46 occupy substantially the entiresurface areaof lthe block 46,*"b`ut few particles will collect on such top"`s'urfaceand substantially all of the particles 'willp'ass into'the hores 48. Asthe 'outlets45 ofthe gamma line 58 is connected so that such particles will be drawn into main line 61.

Inasmuch as the three

spray pistols

15a, 15b and 15C shown in Fig. 1 are energized, the metal tube 11 passing through the spray cabinet 12 will be coated. As Shown, the spray from pistol 15a is directed toward outlet 18, and the spray from pistols 15b and 15C is directed toward the associated exhaust nozzle 21.

By reason of the height of the cabinet 12, the particles sprayed upwardly from pistol 15a will cool before reaching the top wall 19 and hence will not adhere thereto and may readily be drawn out of outlet 18 by reason of the suction created in lines 61 and 63 by suction fan 79.

However, in order that the width of the cabinet 12 be within a practical size, the side walls 16 and 17 are so close to the spray pistols 15b and 15al respectively, that the heated particles sprayed therefrom toward the exhaust nozzles 21 would adhere to the mouth of such nozzles and gradually build up and clog the latter. With the construction of the exhaust nozzle 21 herein shown such diculty is avoided.

Thus when a stream of compressed air is forced into port 39, it will strike baille 38 and be spread through the chamber 41 to emerge with considerable force from the apertures 27 in funnel 26.

As a result, when the heated particles sprayed from a pistol 15 enter the mouth 23 of the opposed exhaust nozzle 21, they will not be able to touch the wall of the funnel by reason of the jets of air discharged through the apertures 27 and hence substantially none of the heated particles will adhere to the wall of the exhaust nozzle but will be drawn therethrough by reason of the suction line 59.

The suction fan 79 connected to collector 64 will cause the particles in hopper 57, in exhaust nozzles 21 and the particles entering outlet 18, to be forced into the collector 64 to strike the wall of cylinder 71. As a result, the particles will be deflected downwardly so that the heavier, coarse particles, as well as type A and B particles, will remain at the bottom of the collector and the smaller and lighter type C particles and particles of still smaller size, formed by the metal spraying operation, will rise by reason of the swirling air currents and be drawn by the fan 79 through

lines

81 and 82 into the cyclone collector.

The coarse particlesv and the type A and B particles will be discharged through the outlet 67 of collector 64 and fall upon the vibrating screen 91. The perforations of the screen 91 are such as to permit passage therethrough of the type A and B particles onto conveyor 94 and the coarse particles will roll down the screen off the discharge end thereof into receptacle 89. The conveyor 94 will then discharge the type A and B particles into air separator 97 for separation and discharge into hoppers 102 and 103 as previously described.

The type C and lighter particles forced into cyclone collector 84 will be separated therein in conventional manner so that the type C particles will be discharged through outlet 86 into hopper 88 and the lighter particles will be discharged through the outlet 85 to the atmosphere or to a suitable collector.

With the system shown in Fig. l, it is merely necessary for an attendant to keep the separator 97 charged with ungraded zinc powder of type A and B particle size. The system will automatically separate such powder into various particle size suitable for spray pistols regulated to accommodate such size and return unused particles and smaller particles to the various separators for separation and use.

Consequently, there is little waste of powder and the system requires but a minimum of supervision to ensure that a suicient supply of powder is always in the air separator 97. lnasmuch as there is no need for stoppage of the spraying operation for replenishing or removal of the powder, the spraying operation is continuous with resultant high rate of production of coated metal tubes.

As many changes could be made in the above system and apparatus, and many apparently widely different embodiments of this invention could be made without departing from the scope of the claims, it is intended Athat all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patents of the United States is:

1. A continuous tlow spraying system comprising a powder distributor having a plurality of inlets on the top surface thereof and a plurality of outlets associated respectively with said inlets, powder supply means having an outlet above the level of the top surface of said distributor and laterally spaced therefrom, an inclined table having its inlet end beneath the outlet of said powder supply means and its discharge end above the inlets of said distributor, means to vibrate said table to distribute the powder fed thereon over the surface of the latter, whereby said powder will ilow down the inclined table into the inlets of said distributor, a plurality of spray means connected respectively to each of the outlets of the distributor, means to force powder from said distributor to said spray means for discharge therefrom, suction means to collect excess powder discharged from said spray means, and means tol feed such excess powder back to said powder supplyr means.

2. The combination set forth in claim 1 in which said plurality of spray means are radially arranged with their outlets directed toward a common line, and longi-l tudinally spaced therealong, and the suction means to co1- lect excess powder discharged from said spray means comprises a collector longitudinally aligned with each of said spray means and spaced therefrom, said collectors each having a suction line associated therewith.

3. The combination set forth in claim l in which heating means are positioned yabove the inclined table to dry the powder thereon.

4. The combination set forth in claim 1 in which electromagnetic means are positioned adjacent the discharge end of said inclined table to remove magnetic metal particles discharged into the distributor.

5. The combination `set forth in claim l in which said distributor has a plurality of longitudinally aligned vertical bores extending completely therethrough, in communication with the respective inlets, and a plurality of transverse bores therethrough extending respectively through each of said vertical bores and in communication with the respective outlets.

6. The combination set forth in claim 5 in which a suction collector is positioned beneath the lower ends of said vertical bores, said suction collector being connected to the suction means to collect excess powder discharged from said spray means.

7. A continuous flow spraying system comprising powder separating means for separating powder into a plurality of particle sizes, said separating means having an inlet and a plurality of outlets for discharge of the separated powder respectively, a powder distributor, means to convey the separated powder from one of said outlets to said distributor, powder spray means to force powder from said distributor to said spray means for discharge therefrom, a second powder separator having an inlet and a pair of outlets, one of said outlets being lower than the other, a suction fan connected to the uppermost outlet, a collector associated with said spray means, a suction line between said collector and the inlet of said second separator, an inclined screen having its inlet end beneath the lower outlet of said second separator, and its discharge end below the level of the inlet end, means to vibrate said screen to sift therethrough powder particles of a predeter- 7 minedsizerangeWhereby'the larger'size-parti'c'lfes Will oW down thenclined screen olf thel discharge end-therebf 1Aand means beneath the s creen to convey the powder partieles siftetkth'erethrdghft'o isa-idf first powder'sep'ara'tor. 8; The 'combination setv forth'in claim 7 in Y'which ithe means-'beneath the screen comprises a Conveyor belt having it's'int-'ake end beneath said'screen audits discharge end over 'the inlet of 'sa-id first powder sepratinglinean's.

9.. The combination set forth 'in "claim 7 'i'n vvWliicl't 'a third separator having an inlet anda pair of outlets, one above -`the level of'the other, has its inlet connected by a'disharge 1line to the outlet of saidsuction fan.

10. The combination set forth in claim 7 inWhich `a third separator having an inlet and a pair 'of" otlets 'one above the other has its inlet Connected by a A"discharge line 'to 'the 'outlet of said 'suction` fan, each of the 'outlets of`saidlfirst separator and the loivermost outlet of said thirdlseparator having a feedhopper rassociated therewith torec'eive the pow'der'fromv the as'soeiatedbutlet.

UNITED STATES PATETJS