US 3837037 A
A means for automatically cleaning magnetic can hangers after they have been used to convey cans through a spray painting station. High pressure water without solvents is sprayed on the hangers from nozzles critically positioned with respect to the path of travel of the hangers through the cleaning station. The impact of the water spray as well as a follow-up application of high velocity air remove the paint deposits. A special covering for the hangers facilitates the paint removal and does not interfere with production runs as the hangers are conveyed through the cleaning station in essentially the same manner as through the painting station. The spray cleaning system utilizes a recirculation system and filtering system which aid the cleaning system in effectively reducing pollution in comparison with prior cleaning methods.
Description (OCR text may contain errors)
United States Patent 1 1 Wright Sept. 24, 1974 HIGH PRESSURE WATER IMPACT SPRAYING SYSTEM FOR MAGNETIC CAN HANGERS Primary ExaminerHarvey C. Hornsby Assistant Examiner-C. K. Moore Attorney, Agent, or Firm Woodcock, Washburn, Kurtz & Mackiewicz  ABSTRACT A means for automatically cleaning magnetic can hangers after they have been used to convey cans through a spray painting station. High pressure water without solvents is sprayed on the hangers from nozzles critically positioned with respect to the path of travel of the hangers through the cleaning station. The impact of the water spray as well as a follow-up application of high velocity air remove the paint deposits. A special covering for the hangers facilitates the paint removal and does not interfere with production runs as the hangers are conveyed through the cleaning station in essentially the same manner as through the painting station. The spray cleaning system utilizes a recirculation system and filtering system which aid the cleaning system in effectively reducing pollution in comparison with prior cleaning methods.
4 Claims, 7 Drawing Figures PAIENIEUSEPZMBH 0 @0000 00000 0 0 QQT PATENTEBSEPZMQH SHEET 3 [IF 5 PMENTEI] SEP 2 4 I974 SHEET 0f 5 HIGH PRESSURE WATER IMPACT SPRAYING SYSTEM FOR MAGNETIC CAN HANGERS BACKGROUND OF THE INVENTION l. Field of the Invention The subject invention has utility for facilities where conveying implements are used to convey articles through a painting or coating process. The cleaning system is designed to utilize the same conveying system as used for painting operations, and thus may readily be adapted to the overall production layout.
The invention has particular utility where magnetic hangers are used to convey cans through a spray painting process in which the exterior of the cans are spray painted or varnished. Once the cans are removed from the hangers, the hangers may be cleaned expeditiously and thoroughly to prevent paint build-up and the operational difficulties which it will cause if not prevented.
2. Prior Art In the past, various cleaning operations, in which paint is removed from conveying implements and the like, have required the use of vast quantities of chemical solvents. The use of such solvents which are usually applied by brushing methods is not only an expensive proposition, but also is a significant pollution factor since the cleaning'residue must then be disposed of, for. example, by burning off'which contributes to air pollution. In addition a potential fire hazard'is created by the storage and utilization of highly inflammable solvents.
Cleaning systems utilizing low pressure water spray such as disclosed in US. Pat. No. 3,355,324 which issued to R. W. Catzen on Nov. 28, 1967 and which discloses a method to remove ink from dies, are generally ineffective in removing paint from objects. For example, as is pertinent to the subject invention, when paint is sprayed onto steel, the releaseproperties of the steel are not sufficient to enable the removal of paint by water impact even when subjected to relatively high pressures.
The use of water as disclosed in Catzen in the range of pressures of from 60 to 100 psi which is common for house outlets such as sink faucets will not by its impact force, remove paint with strong adhering properties from 'most surfaces. Further in the Catzen patent, since dies must be placed on a foraminous belt to be transported under a manifold having overhead spray nozzles and then removed from the belt, there is lacking a disclosure of a method by which implements may be cleaned without disruption as part of'a fully automatic continually operating system, which canform anintegral part of an overall process, such as the production of cans. Catzen further discloses the use of a cleaning agent and therefore does not rely onthe impact of water alone to clean.
SUMMARY OFTHE INVENTION Accordingly, it is an object ofthe subject invention to provide a pollution-free system for cleaning implements used in conveying articles through a painting or coating station.
It is another object of the subject invention to provide a cleaning system which may be used'as a part of an automatic conveying system for the purpose of cleaning relatively permanent implements of the conveying system.
It is a further object of the subject invention to provide a cleaning system for cleaning conveyor implements in which spray stations are individually and uniquely placed to provide optimum cleaning ability.
lt is'still another object of the subject invention to provide a cleaning system for cleaning conveyor implements in which spray stations are positioned at a distance from the path of travel of the objects to be cleaned which is determined as a function of the volume of cleaning water and the pressure at which it is applied.
It is yet another object of the subject invention to provide a cleaning system for cleaning conveyor implements which includes means for recycling the cleaning agent.
Another object of the subject invention is to provide a cleaning system for cleaning conveyor implements which depends on impact pressure cleaning and not the emulsification power of a solvent.
Yet another object of the subject invention is to provide a cleaning system for cleaning conveyor implements which utilizes impact air cleaning in combination with impact water cleaning.
In accordance with the subject invention, a cleaning booth is positioned to enclose a section of the path of travel of magnetic hangers which have been used to convey cans through a painting station. The hangers travel by an overhead monorail conveying system and are rotated as they pass through the cleaning booth. Teflon or other suitable coatings are used to cover the hangers and serve to facilitate removal of paint deposits which occur during the painting process.
As the hangers pass through the cleaning boothat the operational speed in which they travel through their production cycle. they receive a high pressure spray from a number of nozzles positioned throughout the cleaning booth and arranged to spray all portions of the spinning hangers. Each nozzle is positioned at a specified distance from the path of travel of the hangers, the distance being dependent in part on the volume of spray water to be used and the pressure applied in its application. For example, the nozzle orifices may be placed approximately 1% inch from the hangers for a water spray pressure of approximately 6,000 psi and a volume application of 32 gal. per min.
After spraying, the water which at this point includes paint residue washed from the hangers, is drained through a disposable filter paper media and then recycled. Thus, to a certain extent the water in the system need not be replenished except for that which is carried off on the hangers and that which evaporates. The filter paper may be rolled up and conveniently disposed of and in view of the water usage, the pollution ofpast methods involving solvent brushingand the like are eliminated.
As the hangers pass out of the cleaning booth they are subjected to a blast of high velocity air which'further cleans the hangers by causing additional paint deposits to flake off as well as reduces moisture vapor in the area.
The hangers are now free from paint deposits which would otherwise eventually interfere with the operational efficiency of the can painting or varnishing process and thereby hamper production.
BRIEF DESCRIPTION OF THE DRAWINGS For a more detailed understanding of the invention, reference is made in the following description to the accompanying drawings in which:
FIG. 1 is a partial cutaway isometric view showing the cleaning booth, blow-off fan and the water recirculation system;
FIG. 2 is a plan view of the cleaning booth showing hangers being transported therethrough;
FIG. 3 is an isometric detailed view showing the hangers and their conveying system in relation to the spray nozzles of the cleaning booth;
FIG. 4 is an exploded isometric view showing a hanger with teflon cover removed;
FIG. 5 is an elevational view showing a covered hanger with a can attached;
FIG. 6 is an elevational schematic showing the positioning of the spray nozzles within the cleaning booth; and
FIG. 7 is a schematic plan view showing the nozzles in relation to the hanger assemblies.
DESCRIPTION OF A PREFERRED EMBODIMENT With reference to FIG. 1, the high pressure water cleaning booth 10, which is supported by legs and supporting structure 12, is positioned along the path of travel of magnetic hangers 14. The hangers 14 are suspended from a conveying means housed in member 15 and pass through cleaning booth 10 from the left after they have been used to convey metallic cans through a spray painting or varnishing station. Booth 10 has a channel opening 16 extending through its top surfaces to allow the hangers 14 which are supported from above by hanger rod portion 44 to pass through. On the inside of cleaning booth 10, numerous spray stations utilizing spray nozzles 92 with spray heads 18 are located in a manner as will be described. As the hangers 14 pass through cleaning booth 10, the spray nozzles 92 which receive water through manifolds 38, 40 on each side of booth 10 as seen in FIG. 2, spray hangers 14 with high pressure water sprays, the impact of which causes the removal of paint from hangers 14. After spraying the water flows from the cleaning booth bottom (not shown) down drainage ramp 20 to water storage tank 22 via sediment collection basin or tray 19. Water shields 23 positioned on each side of the hanger path of travel at the entry and exit ends of booth 10 assist in preventing spray from leaving booth 10.
A disposable filter media roll 24 is placed at one end of water storage tank 22 and the filter material which may be any standard commercial filter media is extended across tank 22 to intercept the flow of water from drainage ramp 20 and basin 19. The roll material may be supported as well as transported by an endless mesh belt 21 which extends between a roller 23 and other means not shown. Paint deposits are carried to tote box 26 by the filter material where they are collected and then disposed of. The filter material may be advanced by any suitable means such as auxilliary rollers used in conjunction with the conveying system for mesh belt 21 and conveniently disposed of in tote box 26 or by other means. Water which collects in tank 22 is drawn from tank 22 through pipe line 30 by means of suction pump 28 which maybe any standard type. The water is then recirculated back through the system by means of pipe line 32, through which the rate of flow is controlled by valve 32A, where it is drawn to suction header 34. High pressure water pump 36 draws the water through line 35 and pumps it into pressure header 37 by means of line 39 and then through manifolds 38 and 40 (see FIG. 2). The type of pump is not critical, however. a 3-stage plunger triplex type pump with a capability of pumping 32 gallons of water per minute at 6,000 psi may be used. Each of the manifolds 38 and 40 may have approximately 13 spray stations comprising the spray nozzles 18 shown in FIG. 1 which receive water through the high pressure lines 91 fluidly connected with either of manifolds 38 or 40. Pipe line 33 may be used to drain the water from the system by the opening of valve 31 when desired.
A high velocity blow-off fan apparatus 42 is positioned adjacent cleaning booth 10 and the application .of a jet of high velocity air through nozzle structure 51 onto hangers 14 will cause additional paint deposits which may have been loosened by the spray impact to flake and will also dry the hangers 14 as they pass from cleaning booth 10. They may then be conveyed immediately back to the painting station to be used in subsequent painting operations if desired. A tray 53 may be used to collect the additional paint flakes and peelings removed by air from hangers 14.
The hangers 14 are conveyed through the plant painting station (not shown) and the cleaning station by means of a monorail conveying system (not shown) which is housed in the support member 15. The hangers 14 are attached to the monorail conveyor by means of rod members 44 and any standard connecting means. Customarily, facilities for transporting two rows of hangers 14, side by side, are used as shown in FIG. 1. Near the top of rods 44 horizontal guide bars 54 are positioned to the top and bottom of knurled roller 56 as best seen in FIG. 3. As rods 44 and associated hangers 44 are conveyed. the rollers 56 will be engaged by vertical bearing posts 55 (see FIG. 1) or other means placed adjacent each row of hangers 14 which will cause rollers 56 to rotate thereby spinning hangers 44 as they pass through cleaning booth 10. As rollers 56 impact with bearing posts 55, the guide bars 54 serve to keep hangers 14 from tipping to the right or left by passing closely to stationary stabilizing horizontal bars 93, 94 (see FIG. 7) disposed to the right and left of the path of the guide bars 54 through the cleaning booth l0.
Spray nozzles 92 with nozzle head 18 as shown in FIG. 3 are supported in spraying position by pivotal locking members 58 which may be secured to connecting supports 60 which are positioned along cylindrical uprights 62. Bolts 59 are used to secure members 58 and as can be seen from FIG. 3 the angle of approach of nozzles 92 and the distance of nozzle heads 18 from hangers 14 may be adjusted. Supports 60, each separable in half, are adjustable by means of bolts 61 and bolts 59 which extend through members 58, and may be placed at any height along uprights 62 to set the nozzle location, i.e., height, distance from hanger and angle of spray. Uprights 62 are secured between top and bottom frame members 64 and 66 respectively which are secured in parallel relationship to the path of travel of the hangers 14 through booth 10. Flexible hoses 91 leading from manifolds 38 and 40 connect at connection 98 to the extended nozzle structure 92,
which extends through pivotal member 58,'and supply the high pressure water.
As previously described, each hanger 14 suspends by means of hanger rod member 44. As seen in FIG. 4, the rod member 44 comprises an inner steel member 80 which connects at its base to magnetic body member 46 by any suitable connecting means such as by the clamping of rod groove member 81 and magnet grooved member 82. The greatest part of steel rod-80 is covered by teflon sleeve 45 as best seen in FIG. 5. The magnetic body member 46 has an upper portion 83 and a lower portion 84, the lower portion comprising the actual magnetic surface. The upper portion 83 of magnetic body member 46, the base of steel rod 80 and the connecting parts 81 and 82 are protected from paint by a conical teflon cover 47 which may be slipped in place while magnetic member 46 is detached. As seen in FIG. 5, the magnetic surfaces 84 are not covered by the teflon cover 47 and may engage the upper inner cylindrical surface of a metallic can 49 for the painting process. It will be noted from FIG. 5 that by means of teflon sleeve 45 and teflon cover 47, all of the hanger 14 including most of rod member 44 is covered with the exception of the magnetic portion 84. As can be seen from FIG. 5, however, magnetic portion 84 is protected in large measure from paint by the can 49 during the painting process. Prior to the cleaning step, the cans 49 are removed by a detent means onto a conveyor belt or will otherwise be detached from the magnetic hangers 14 which are then transported through the cleaning booth without the cans 49.
The teflon sleeve 45 and cover 47 greatly facilitate the paint removing process. It has been found that paint adheres to steel in such a manner that it is very difficult to remove it by the impact of water alone without the use of solvents heretofore applied by brushing. The conical shape of cover 47 is so designed to provide the best shape for facilitating the removal of paint by pressure means.
The positioning of the spray nozzles 92 in cleaning booth 10 is critical in the sense that the spray heads 18 must be placed a precise distance from the path of travel of hangers 14. The teflon sleeve 45 and cover 47, while necessary to facilitate removal of paint residue from the hangers 14 by the high pressure water, will nevertheless erode if the water pressure is too great; on the other hand, if the nozzle heads 18 are positioned at too great a distance, the impact force will not be sufficient to remove the paint. Thus, the relationship of nozzle distance from the hangers versus pressure of water used is a critical one and must be established for optimum conditions. *A further factor is also the volume of water which is sprayed on the hangers from the nozzles. As an example, one such optimum condition has been the utilization of a water pressure of 6,000 psi pumped at the rate of 32 gal/min in combination with the positioning of the nozzles 18 approximate inch from the path of travel of the hanger surfaces.
With reference to FIG. 6, the inflow of water through pipes 39 schematically shown, supplies manifold 40. From there, the water is pumped through one of the series of manifold outlets 90 into hose member 91 which may be a flexible. rubber hose. It is to be understood that the additional twelve manifold outlets all have hoses like member 91 connected to the various spray stations. The hoses 91 feed into the nozzle head structure best shown in FIG. 3, as previously described.
While each of the hoses extend to a nozzle extension 92 at a connecting block 58, only one such connection is shown in FIG. 6. A full set of vertical hold blocks 60 are shown, however, in a range of positions as illustrated by B, C', D, E', F, G, H, J, K, L, M, N and P. The positions of the corresponding spray nozzle heads 18 are shown schematically by the letters, B, C, D, E, F, G, H, .I, K, L, M, N, and P. The general positions of the extensions 92 are shown by the dotted lines, for example, the dotted line from block D to spray station D.
Structure 99 in FIG. 6 schematically shows an auxiliary manifold which may be used along the end of the spray booth 10. Two such manifolds may be used, one for each of the rows of hangers. As shown, manifold outlet A can be connected with spraying means, the spray nozzle of which might be set at position A.
Along with the criticality of the distance placement of the nozzles from the hangers, it is important to position the nozzles so that all the surface areas of the hangers are covered. For example, with reference to FIG. 5 the conical teflon cover area 67 and the surrounding base area collect more paint than the teflon sleeve portion 45 and should, of course, receive substantially more impact spray. This is controlled by placing more nozzles 18 in position to cover this portion of the hangers. For example, with reference to FIG. 6, the nozzle heads C, D, E, G, H, K, M, N, and P, are all positioned to spray in part or totally the lower surfaces of hangers 14. The direction of spray may be further controlled by the positioning of the nozzle 92; either vertically by adjusting member 58 and support 60 as previously described, or horizontally by turning support 60 to right or left before tightening bolt 61 to set the lateral direction of nozzle extensions 92 as best seen in FIG. 7.
Also, with further reference to FIG. 7 the auxiliary spray stations as alluded to in the FIG. 6 description are shown with their respective nozzle extensions extending physically from columns 95 and 96.
The positioning of the nozzles as shown should not be considered limiting, but reflects a necessity for controlling the positioning of the nozzle heads 18, as well as, the direction of the flow so that all of the hanger surface areas will be sprayed. The hangers 14 will be spinning as they pass through the cleaning stations and this factor must be taken into consideration in the place ment of the nozzles 92.
An empirical approach may be used in the placement of nozzles 92 or an optimum placement chart derived from mathematical data including the speed of travel of hangers and the spin data as controlled by the placement of bearing posts 55.
While various embodiments of the invention have been shown and described, it will be understood that various modifications may be made. The appended claims are, therefore, intended to define the true scope of the invention.
1. Cleaning apparatus for cleaning hangers used in conveying articles through a painting station comprising:
a housing structure;
pumping means to pump water at high pressure;
spraying means including spray nozzles optimally positioned within said housing structure to spray high pressure water from the pumping means onto the hangers to remove painting deposits from said hangers by the impact force of the water, said spray nozzles being positioned at a distance from the path of travel of the hangers, said distance being determined as a function of the pressure to be used;
means to convey the hangers through the housing structure;
means adjacent said housing structure to apply high velocity air onto the hangers; and
recirculation means adjacent said housing structure for recirculating the spray water through said pumping means and spraying means including drainage facilities having filter means.