Patent Publication Number: US-6663017-B2

Title: Device for generating a pressurized stream of treating media

Description:
RELATED APPLICATION 
     This application claims the priority benefits of U.S. Provisional Patent Application Ser. No. 60/178,617 filed Jan. 28, 2000. 
    
    
     FIELD OF THE INVENTION 
     The present invention is generally directed to a device for generating a stream of solid particulate matter or liquid which is provided at sufficient pressure and velocity so that it can remove solid debris, difficult stains and other unwanted materials (e.g. glues, adhesives, etc.). The device can be constructed on a large scale for and removal of unwanted materials from large objects such as platforms, floors and the like. The device can also be constructed on a small scale wherein the substrate may be as small as a large size coin. 
     BACKGROUND OF THE INVENTION 
     Devices for generating a stream of pressurized particulate matter such as sand blasters are known in the art. Such devices employ solid particulate matter (e.g. sand) which has been accelerated by a pressurized gas or liquid to provide a pressurized stream which can be directed at a substrate. 
     Such devices are successful in generating a pressurized stream of solid particulate matter. However, they suffer from a number of disadvantages including a lack of control of the substrate damage due to the pressurized stream and problems with cleaning up the solid particulate matter. 
     Most devices employ an abrasive material as the solid particulate matter such as sand, glass beads, and plastic beads. Most of the solid abrasive materials customarily employed are difficult to dispose of after use and/or present environmental problems. This is because the solid particles must be collected or swept from the area around the substrate and properly disposed of. This requires significant cost and in some cases the solid particulate matter comes under environmental scrutiny leading to waste disposal problems. 
     For those devices which employ non-abrasive materials, they are disadvantageous because they do not provide the combination of manageable size and control of the pressurized stream and/or are not easily connected to a single fluid source through conventional fluid supplying and pressurizing equipment. 
     It would therefore be a significant advance in the art of treating substrates with a pressurized stream of a treating media in the form of a solid particulate matter, liquid or mixtures thereof if sufficient control can be provided to the stream by controlling the rate and pattern of flow of the treating media. 
     It would be a further advance in the art if the treating media was safe and effective to use and could be easily disposed of without raising environmental concerns. 
     SUMMARY OF THE INVENTION 
     The present invention is generally directed to a device for generating a pressurized stream of a treating media in the form of solid particulate matter, liquid or mixture thereof in which a pressurized fluid (i.e. gas, liquid or combination thereof) and the treating media are combined in a manner which produces a controllable stream. In a further aspect of the present invention, the treating media in the form of solid particulate matter, liquid or mixture thereof is comprised of a compound or mixture of compounds which can be easily disposed of by washing the substrate and surrounding area with an environmentally acceptable liquid (e.g. water). 
     In a particular aspect of the present invention there is provided a device for generating a pressurized stream of a treating media selected from the group consisting of solid particulate matter, liquid and mixtures thereof comprising: 
     a) a vessel for housing the treating media up to an upper level; 
     b) pressurized fluid delivery means for delivering pressurized fluid to the vessel above the upper level of the treating media contained within the vessel; and 
     c) a first conduit for transporting the pressurized treating media out of the vessel including an open end lying below the upper level of the treating media for receiving the treating media when pressurized by the pressurized fluid within the vessel, an opening positioned above the upper level of the treating media for receiving a portion of the pressurized fluid, and an opposed end for delivering the pressurized stream of the treating media. 
     In a preferred form of the present invention, the treating media is comprised of solid particulate matter and most preferably one or more water soluble bicarbonate or carbonate compounds which facilitate removal from the substrate by an environmentally acceptable liquid such as water because the same are soluble therein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following drawings in which like reference characters indicate like parts are illustrative of embodiments of the invention and are not intended to limit the invention as encompassed by the claims forming part of the application. 
     FIG. 1 is a side view in partial cross-section of an embodiment of the device in accordance with the present invention; 
     FIG. 2 is a side view in partial cross-section of another embodiment of the pressurized fluid delivery assembly for generating pressurized fluid to mix with the treating media; and 
     FIG. 3 is a cross-sectional view of an embodiment of a manifold employed in an embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is generally directed to a device for generating a pressurized stream of a treating media employing a vessel for combining the treating media and a pressurized fluid stream, a pressurized fluid delivery assembly for delivering the pressurized fluid to the vessel and a conduit for transporting the pressurized treating media out of the vessel and towards a substrate for cleaning or other similar purpose. 
     As used herein the term “treating media” shall mean any solid particulate matter or any liquid or mixtures thereof which can be pressurized and delivered towards a substrate for cleaning or other purposes. Examples of solid particulate matter include, but are not limited to, bicarbonates, carbonates, oxides, silicas, plastic materials, glass beads and the like. Examples of liquids include, but are not limited to, surfactants, detergents, solvents and the like. 
     Referring to FIG. 1, there is shown an embodiment of a device  2  in accordance with the present invention for delivering a pressurized stream of treating media. By way of example only, the treating media will be hereinafter described with regard to the drawing figures as “solid particulate matter”. The device  2  includes a vessel  4  which is loaded with the solid particulate matter  6  up to an upper level  8 . An opening  10  is provided at the top of the vessel  4  enabling a conduit  12  to extend into the vessel  4  toward the bottom end thereof. The conduit  12  has an opening  14  which, as explained hereinafter, provides an entry for pressurized solid particulate matter to enter the conduit. 
     The conduit  12  extends out of the vessel  4  where it is in operable connection with a fluid delivery assembly  16 . As used herein, the term “fluid” is intended to cover gases, liquids and combinations thereof. The fluid delivery assembly  16  includes a source of compressed fluid (not shown) which may be within or without the device which plugs into a connecting assembly  18  including optionally a water vapor trap  17  for removing water from the pressurized fluid, (see FIG. 2) a shut-off valve  20 , and a conduit  22  which may include a pressure gauge  24  to monitor the pressure of the pressurized fluid. A pressure release valve  26  may be provided to prevent against over pressurization the device  2  including the conduit  12  and the vessel  4 . The pressure release valve  26  may be located at any point which is in contact with the pressurized fluid emanating from the source thereof. 
     The conduit  22  of the connecting assembly  18  is operatively connected to a manifold  28  which provides the opportunity for the pressurized fluid to be delivered to the vessel  4  and in a particular embodiment of the invention to provide a separate stream of pressurized fluid upward through the conduit  12  which extends out of the vessel  4 . 
     In the particular aspect of the present invention shown in FIG. 1, the conduit  12  receives pressurized fluid from the fluid delivery assembly  16  which enters the top end of the vessel  4 . The pressurized fluid exerts pressure on and mixes with the solid particulate matter  6  to provide a pressurized stream of solid particulate matter for entry into the opening  14  of the conduit  12 . At the same time, a separate stream of pressurized fluid enters the conduit  12  at a point above the upper level  8  of the solid particulate matter through an opening within the conduit  12 . As shown specifically in FIG. 1, the opening  13  is positioned within the conduit  12  at a point within the vessel  4 . The pressurized fluid enters the opening  13  and thereby creates a pressure differential which draws the pressurized solid particulate matter entering the opening  14  upward through the conduit  12  so that it may proceed to a pressurized stream of solid particulate matter delivery system hereinafter designated by numeral  30 . 
     In an alternative aspect of the present invention as shown specifically in FIGS. 2 and 3, the pressurized fluid enters an opening  13   a  at a point outside the vessel  4 . In this embodiment of the invention, the pressurized fluid stream from the fluid delivery assembly  16  may be branched so that a portion of the pressurized fluid goes down into the vessel  4  as previously explained and another portion enters the opening  13   a  to create the pressure differential as previously described. The opening  13   a  may typically be at the junction of the conduits  22  and  12  or in close proximity thereto. 
     The opening  13  or  13   a  which provides access to the conduit  12  of the pressurized fluid should be of sufficient size to enable a sufficient amount of pressurized fluid to enter the conduit and create a sufficient pressure differential so as to assist in drawing the pressurized solid particulate stream upward through the conduit  12 . The size of the opening may vary depending on the size of the conduit. In general, the ratio of the size of the opening and the internal dimension of the conduit (e.g. diameter) is from about 1:1 to 1:20, preferably at or about 1:10. By way of example, a conduit having a diameter of 0.25 inch would suitably have an opening  13  or  13   a  measuring about 0.25 inch. As previously indicated, the size and shape of the opening  13  or  13   a  may vary so long as a sufficient pressure differential is created to assist in drawing the pressurized treating media stream such as a pressurized solid particulate matter stream through the delivery system  30 . Alternatively, a bypass valve assembly incorporating a fluid control device such as a ball valve or needle valve may be used to provide a pressurized fluid stream from the conduit  22  to the conduit  12  at a location within the manifold  28 . 
     Referring again to FIG. 1, the solid particulate matter delivery system  30  includes an extension of the conduit  12  or a second conduit  32  connected to the first conduit  12  through a connector  34 . Such connectors are well known in the art. The second conduit is provided at an end  36  opposed from the connected end with an opening  38  which may deliver the pressurized solid particulate matter to a substrate. In a preferred embodiment of the invention as specifically shown in FIG. 1, there is provided a nozzle assembly  36  which provides for the controlled release of the pressurized stream of solid particulate matter from the device  2 . The nozzle  36  has at least one opening  38  for emitting the pressurized particulate matter. The nozzle  36  may be provided with multiple openings  38  to provide larger coverage of the targeted substrate. It will be understood that the size of the opening or openings  38  may be routinely adjusted depending on whether the treating media is a solid particulate matter, a liquid or mixtures thereof. 
     In a preferred form of the invention, the treating media is solid particulate matter  6  and is principally made of water soluble compounds such as bicarbonates (e.g. sodium and calcium bicarbonates) or carbonates (e.g. calcium carbonate) so that they can be readily dissolved and washed away in the clean up operation. This provides distinct advantages over prior art systems which employ non-soluble solid particulate matter (e.g. sand) which provides more difficult clean up. Bicarbonates and carbonates also provide advantages oversolid particulate matter materials (e.g. water soluble, easy waste disposal, non-toxic, non-substrate damaging) which present environmental concerns. 
     The vessel  4  is typically made of materials which can withstand pressurization typically up to and exceeding 300 psi. In most cases, for moderate sized cleaning operations, a vessel rated to 120 psi is acceptable. The vessel can be made of a variety of plastic and metal materials. For long term use, steel is the preferred material of construction because of its long term resistance to abrasion. Plastics are the preferred materials for short term or disposable units because they are relatively inexpensive to produce. 
     The conduit  12  employed within the vessel  4  is preferably made of a rigid plastic or metal material. The preferred materials are the same as those that may be used to construct the vessel. The conduit  32 , as previously indicated, may merely be an extension of the conduit  12 . In a preferred form of the invention, the conduit  32  is made of a flexible materials that are appropriately pressure rated and desirably abrasive resistant (for long term use) such as rubbers, rubber composites, polypropylene, polyethylene, and combinations thereof. 
     The operation of the device of the present invention is as follows. Pressurized fluid is applied to the device by opening the pressure shut off valve  20 . It will be understood that the source of the pressurized fluid may be contained within or without the device. Pressurized fluid then enters the vessel  4  through the opening  10  therein to provide pressurized treating media such as solid particulate matter which enters the opening  14  of the conduit  12 . At the same time pressurized fluid enters the conduit  12  at the opening  13  or  13   a  to assist in drawing the pressurized particulate matter through the conduits  12  and  32  and out the opening  38  of the delivery system  30 . Preferably there is provided a nozzle  36  to assist in controlling the release of the pressurized stream of the treating media. 
     The device of the present invention may be used in conjunction with a protective device over at least the nozzle to minimize the area over which the treating media is sprayed during cleaning.