I. Field of the Invention
This invention relates generally to apparatus for industrial pre-cleaning of machine parts prior to painting or powder coating of such parts, and more particularly to a multi-stage, in-line washer whereby parts to be cleaned are subjected to a pressurized spray at elevated temperatures of chemical cleaning solutions for predetermined time periods determined by the number of stages employed.
II. Discussion of the Prior Art
As explained in the Pascaru U.S. Pat. No. 5,257,739, machined parts must be chemically cleaned to remove oils and other residues therefrom before painting or powder coating operations can be performed on these parts. Spraying equipment used to clean, rinse and otherwise treat articles of manufacture take place in a confined area, such as a spray or washer booth, in which various liquids are piped under pressure through headers into a plurality of vertical pipes, called risers, that connect to the headers and then out through nozzles attached to the risers and which are adapted to forcefully spray work pieces as they pass through the washer booth being transported by an overhead conveyor or other suitable transport mechanism.
As further explained, prior art washer booths are customarily made of steel and are equipped with a pair of header pipes that are spaced apart and that run parallel and longitudinal to the floor or ceiling of the washer booth. Industrial liquids are stored in a tank beneath the washer booth floor and are pumped through suitable plumbing to the headers. A bank of plastic or steel risers is connected to each header and extends upward or downward along an adjacent wall of the washer booth depending on the header's placement. Parts to be treated may be carried through the booth and exposed to chemical spray by a suitable conveyor.
Pretreatment systems have four major process requirements needed to affect suitable parts cleaning. They are:
The concentration, pressure and temperature are capable of adjustment once the washer is built, but after a washer has been built; the exposure time is fixed, based on the length dimension of the washer and each of its stages.
For example, assume a company has designed to run a conveyor of the parts to be cleaned at 4 feet per minute and that three process stages are required. Three process stages typically require two drip zones, one entrance and one exit vestibule with a 1 minute soak time required in each stage. Under these assumptions, a wash booth would have to be 28 feet in length. Over time, should the company decide to increase the conveyor speed to add throughput, it would have to sacrifice soak time or, alternatively, add length to the washer, usually at considerable expense. Also, if the company needs to add another stage to improve its process or possibly add another type of process, it will not be able to do that without substantial added cost. In the case of the prior art, it is a major project to add length to a washer or to shorten it.
Existing washers of which we are aware typically occupy a significant amount of factory floor space and are inefficient in terms of energy needed to pump and heat the liquid cleaning agents.
Those skilled in the art, then, can appreciate that a need exists for an in-line pretreatment system that is modular in design, allowing stages to be easily added or removed based upon customer requirements.
Another problem with prior art parts washer booths is that they do not permit easy access to the piping system comprising the nozzles, risers and headers contained within the booth so that adjustments may be made to the direction and spray pattern employed. Thus, a need exists for an in-line pretreatment system that allows easy access to interior components for cleaning, adjustment repair and replacement.
Another drawback of prior art washers is that they need some type of filtration system in the first wash stage to help keep the bath clean so as to offer an extended bath life. The filtration systems commonly employed require an additional pump and bag filtration system typically placed adjacent to the washer. Such filtration systems therefore require additional energy and floor space. A need therefore exists for a more compact and energy efficient way for filtering the wash chemicals.
It is therefore a principal object of the present invention to provide an in-line pretreatment system for washing machine parts that solves the aforementioned problems attendant in known prior art systems by providing a modular configuration of different length stages that can be concatenated to vary the time of exposure and the types of chemicals needed for the cleaning process at hand. The modules have been specifically designed to provide greater flexibility and ease of access to interior components while also reducing the overall footprint and energy consumption needed to operate the system.
A pre-washer assembly for use with an overhead conveyor that is adapted to carry machine parts through the pre-washer assembly for cleaning prior to their being painted or powder coated comprises a plurality of concatenated wash stages where each wash stage includes a base frame assembly having a motor-driven pump mounted thereon and also supporting a generally rectangular tank. The tank itself has opposed sidewalls and end walls that extend upward from a closed bottom wall to define an open top. The tank is adapted to hold a cleaning liquid supply therein. First and second upright assemblies are attached individually to the opposed sidewalls of the tank and each of the upright assemblies includes a plurality of inverted, L-shaped uprights that are held in parallel, spaced-apart relation by horizontally extending cross-members. The upper legs of the uprights affixed to the opposed sidewalls of the tank extend toward one another but with a gap between opposed ends of the inverted L-shaped uprights. First and second roll formed plastic shrouds removably attach to the first and second upright assemblies, forming a cabinet-like structure partially surrounding horizontally extending headers and upwardly extending riser pipes to which plural spray nozzles are joined. A motor-driven pump, preferably a centrifugal pump, is arranged to draw the cleaning liquid from the tank and supply it via the headers to the risers and nozzles.
The foregoing features, objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of a preferred embodiment, especially when considered in conjunction with the accompanying drawings in which like numerals in the several views refer to corresponding parts.
This description of the preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. In the description, relative terms such as “lower”, “upper”, “horizontal”, “vertical”, “above”, “below”, “up”, “down”, “top” and “bottom” as well as derivatives thereof (e.g., “horizontally”, “downwardly”, “upwardly”, etc.) should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms such as “connected”, “connecting”, “attached”, “attaching”, “join” and “joining” are used interchangeably and refer to one structure or surface being secured to another structure or surface or integrally fabricated in one piece, unless expressively described otherwise.
Referring first to
Without limitation, the wash stages or modules 12, 14 and 16 may be produced in two sizes, i.e., they may have an overall length dimension of about 4 feet or 6 feet. Likewise, the drip modules 18 and 20 may also be made in both 4 feet and 6 feet lengths. The entry module 22 and the exit module 24 will typically be 4 feet in length. By providing washer modules in 4 foot or 6 foot increments, stages can be assembled to equal 4, 6, 8, 10 and 12 foot zones. The entrance and exit modules 22 and 24 and the drip zones 18 and 20 serve to contain the spray and keep the cleaning liquid in the proper stages as the parts are carried through the washer by the overhead conveyor (not shown). As will be further explained, when two wash stages are to be joined to one another in directly adjacent relation, a narrow drip stage is used to collect overspray or splash and return it to the tank of a wash stage.
As seen in
As seen in
Other apertures are formed through the front wall of the tank to accommodate electrical controls 79 leading to immersible heater modules 81 disposed within the tank 60 for controlling the temperature of the cleaning liquid. Alternatively, an external gas heater and pump may be used to feed heated cleaning elements to the tank. Also, a drain aperture is provided in which a gate valve 83 is placed to allow dirty fluid to be periodically drained from the tank. Enclosure 85 contains control circuitry for the pump motor 87.
Chemically welded or otherwise bonded to the opposed sidewalls 64 and 66 of the tank are upright assemblies 72, a portion of which can be seen in
The upright assemblies 72 are designed to support first and second spray shrouds 82 and 84. The bottom edge of each of the shroud members 82, 84 is suspended over a drip edge member 86 that rests upon the upper portion of the tank 60 and that has a flange extending over the peripheral edges of the tank 60 such that sprayed liquid running down the inside walls of the spray shrouds 82 and 84 will flow onto the drip edge member 86 and flow back into the tank 60.
Referring next to
The drip stages 18 and 20 shown in the in-line pretreatment system of
With continued reference to
Like the long drip tray of
The drip shroud 114 also includes a pair of spaced apart, vertically oriented handles 128 that are shown in phantom line in
The wash module of
The filter tray 130 is adapted to be supported by the structure 144 shown in
The filter tray support 144, when placed within the tank, allows the filter tray of
From what has been described, those skilled in the art will recognize that the present invention offers part finishers and environmentally friendly product that combines never before seen flexibility of high volume throughput with low capitol outlays and operating costs along with the ability to react to constantly changing production demands and that is capable of utilizing present day low temperature chemistries. As processes change, the in-line pretreatment system of the present invention can easily be adapted to meet customer demands. It has been shown how wash and drip modules can be easily added or removed to change the exposure time of treatment. Likewise, chemistries can easily and quickly be changed by draining a tank of a first chemistry and replacing it with another. Due to the small capacity of the tanks employed, there is less concern of exceeding local wastewater discharge permit levels. Also, the small footprint of the apparatus makes an in-line cleaning process possible in facilities where space is at a premium and known prior art devices are unable to be used because of space limitations.
This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use such specialized components as are required. However, it is to be understood that the invention can be carried out by specifically different equipment and devices, and that various modifications, both as to the equipment and operating procedures, can be accomplished without departing from the scope of the invention itself.
Number | Name | Date | Kind |
---|---|---|---|
2547884 | Paasche | Apr 1951 | A |
3942420 | Marino | Mar 1976 | A |
3960323 | Ducan et al. | Jun 1976 | A |
4327756 | Rath | May 1982 | A |
4381794 | Stimac et al. | May 1983 | A |
4924803 | Celant | May 1990 | A |
5000985 | Salisbury | Mar 1991 | A |
5253665 | Guirl | Oct 1993 | A |
5257739 | Pascaru | Nov 1993 | A |
5259879 | Khattab | Nov 1993 | A |
5264037 | Salisbury | Nov 1993 | A |
5443642 | Bienduga | Aug 1995 | A |
5564159 | Treiber | Oct 1996 | A |
5582440 | Pascaru | Dec 1996 | A |
5630435 | Brouchoud | May 1997 | A |
5758674 | Taeger | Jun 1998 | A |
6120604 | Hawkins | Sep 2000 | A |
6675066 | Moshgbar | Jan 2004 | B2 |
20070224343 | Langlois | Sep 2007 | A1 |
20090277384 | Spangler et al. | Nov 2009 | A1 |
20100008749 | Spangler et al. | Jan 2010 | A1 |
Number | Date | Country |
---|---|---|
WO 9208549 | May 1992 | SE |
WO 2005068269 | Jul 2005 | WO |
Number | Date | Country | |
---|---|---|---|
20130306114 A1 | Nov 2013 | US |