Patent Application
20170173641
Field of the Invention
This application is directed, in general, to blasting systems and, more specifically, to systems and methods for removing surfacing materials from a work surface through wet blasting.
Description of the Related Art
Certain building materials contain toxic materials which are harmful to people, such as asbestos or lead, for example. Inhalation of asbestos fibers, in particular, has been found to cause lung cancer, mesothelioma, and asbestosis. Unfortunately, before building materials containing asbestos, lead, and the like were found to be toxic, those materials were widely used throughout the construction industry in a multitude of surfacing materials and insulating materials. Surfacing materials may comprise building materials which may be sprayed, troweled, or otherwise applied to a surface of a structural component of a construction. More specifically, surfacing materials may comprise: paints; insulation; fireproofing materials; acoustic or texturing materials; spackling; compounds for patching and/or taping; adhesives; plasters; roofing materials; and the like. These surfacing materials are applied to various structural components of a construction, such as pipes, fittings, boilers, breeching, tanks, ducts, walls, floors, ceilings, and the like. Hereinafter these structural components may be referred to, collectively, as “works.” Further, hereinafter, the external surfaces of works to which surfacing materials may be applied may be referred to, collectively, as “work surfaces.”
The renovation, or demolition, of constructions built with toxic surfacing materials has become particularly problematic for builders and property developers. Oftentimes, these toxic surfacing materials must be removed from a construction and disposed of before any further renovation or demolition activities on the construction may be performed. Further, the removal and disposal of toxic surfacing materials are heavily regulated to ensure the safety of persons working in and near the work area in which such activities are performed by limiting the exposure of such persons to the toxic surfacing materials.
For removal of non-toxic surfacing materials, those which may not contain asbestos, lead, and the like, the fastest and most cost-effective removal method is dry abrasive blasting of the work surfaces. Dry abrasive blasting typically involves propelling a mix of abrasive and compressed air against a work surface to remove the surfacing materials. While dry abrasive blasting may be faster and cheaper than other known removal methods, dry abrasive blasting operations produce large amounts of airborne waste in the form of dust due to the abundance of friable material present in a dry environment. Friable materials may be those materials which can be crumbled, pulverized, or reduced to powder by hand pressure when dry, and may include the toxic surfacing material, itself, as well as certain abrasives which may be used as part of the dry abrasive blasting operation.
For asbestos abatement activities, which may be any activity which involves the removal, dislodging, stripping, encapsulating or enclosing of toxic surfacing materials containing asbestos, dry abrasive blasting operations are undesirable due to the large amount of solid waste in the form of dust which is produced by dry abrasive blasting. The waste dust produced contaminates the air within and around the work area, creating an unsafe condition for those exposed to the waste dust produced due to the potential for inhalation of airborne asbestos fibers.
Due to the risk of exposure to asbestos fibers, in particular, asbestos abatement activities are closely regulated and must be carried out in accordance with several safety regulations intended to reduce the amount of asbestos fibers introduced into the air supply during the abatement activity, thereby minimizing the exposure of workers and others to the asbestos fibers. For example, abatement activities often require, among other safeguards, isolation of the work area, creation of negative pressure environments for control and collection of solid, airborne waste produced, the use of respirators, as well as sampling and analysis of air within and near the work area to ensure that asbestos exposure remains below defined exposure limits. These safeguards serve to ensure that Permissible Exposure Limits (PELs), as defined by state and federal statutes, including Occupational Safety and Health Administration (OSHA) regulation 29 CFR §1926.1101, entitled Asbestos Standard for Construction Industry, are not exceeded. At present, OSHA defines the applicable PELs as: 0.1 fibers per cubic centimeter of exposure as an eight hour time-weighted average; and, 1.0 fiber per cubic centimeter of exposure averaged over a thirty minute period. The amount of exposure to asbestos may be determined using air quality analysis for air within or outside the work area, such as phase contrast microscopy (PCM).
Due to the health risks associated to asbestos abatement activities, and associated health and safety regulations, existing apparatuses and methods for performing abatement activities for the removal of toxic surfacing materials are largely inefficient and slow, requiring many operators and extensive preparation of the work area and clean up. A need exists for improved apparatuses and methods allowing for faster, cheaper asbestos abatement while remaining in compliance with any and all applicable health and safety regulations.
An apparatus and method for removal of toxic surfacing materials from a work surface via an abrasive blasting operation are provided herein.
For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following Detailed Description taken in conjunction with the accompanying drawings, in which:
Referring to
In such an embodiment, the blasting apparatus 1000 may be configured to accommodate a “wet” abrasive blasting operation, which may be an abrasive blasting operation in which the blast media and waste material produced remains sufficiently wet to militate against the production of waste in the form of airborne dust particles. In an embodiment, the “wet” abrasive blasting operation accommodated by the blasting apparatus 1000 may maintain the blast media as well as the waste produced in a state in which they remain sufficiently mixed or penetrated with liquid that no dry blast media or waste is present in the work area, effectively preventing the release of particulates into the local air supply in the form of waste dust. All waste produced through a “wet” abrasive blasting operation, as accommodated by the blasting apparatus 1000, may pool along the floor of the work area rather than be released into the air.
Referring to the particular embodiment shown in
According to the embodiment of
In an embodiment, the first conduit section 102 may comprise a length of hose, tube, pipe, or the like and may comprise two open ends. The first conduit section 102 may comprise a plastic, metal, composite, or other material which may be suitable for receiving and routing received liquid. The first conduit section 102 may be configured to couple to a water source which may comprise a pipe, tank, reservoir, or other vessel suitable for storing a liquid. The first conduit section 102 may couple to the water source at an inlet end of the first conduit section 102. The first conduit section 102 may be configured to couple to the connector 200 at an outlet end of the first conduit section 102, whereby water received by the first conduit section 102 may be routed from the water source to the connector 200 (as indicated by the arrows shown in
As shown in
In an embodiment, the second conduit section 104 may comprise a length of hose, tube, pipe, or the like and may comprise two open ends. The second conduit section 104 may comprise a plastic, metal, composite, or other material which may be suitable for receiving and routing received liquid. The second conduit section 104 may be configured to couple to the additive supply 108, which may comprise a pipe, tank, reservoir, or other suitable vessel for storing a liquid. The second conduit section 104 may couple to the additive supply 108 at an inlet end of the second conduit section 104. The second conduit section 104 may be configured to couple to the connector 200 at an outlet end of the second conduit section 104, whereby additive received by the second conduit section 104 may be routed from the additive supply 108 to the connector 200 (as indicated by the arrows shown in
In an embodiment, the additive stored within the additive supply 108 and directed to the connector 200 via the second conduit section 104 may comprise, at least, a surface acting agent, or surfactant. In alternative embodiments, the additive stored within the additive supply 108 may additionally comprise one or more fluids which may include rust retardants, pesticides, disinfectants, insulating or fireproofing solutions, and the like.
Surfactants may be compounds that lower the surface tension, or interfacial tension, of a liquid to which the surfactant is added, allowing the liquid to spread more easily. Importantly, surfactants may promote greater spreading of a liquid over the surface area of solid materials which the surfactant-and-liquid solution may come into contact with. In an embodiment, the additive 108 may comprise, at least, one or more surfactants of any known type which may function to decrease the surface tension of water, whereby the additive 108 may function as a wetting agent when mixed with water.
Referring to
In an embodiment, the connector 200 may comprise a section of hose, tube, pipe, or the like, which may be composed of plastic, metal, composite, or other suitable material for receiving and routing fluid flows within the blasting apparatus 1000. According to the embodiment shown in
According to the embodiment shown, the connector 200 may couple with the first conduit section 102 at the first inlet 202, the second conduit section 104 at the second inlet 206, and the third conduit section 110 at the outlet 204. Accordingly, the connector 200 may receive water and additive from the first conduit section 102 and the second conduit section 104, respectively, which may combine within the connector 200. The combined water and additive may comprise amended water. The amended water may be routed into the third connector 110 via the outlet 204 of the connector 200. Importantly, the amended water may comprise one or more fluid characteristics differing from that of the source water received at the first inlet 202. For example, the amended water may comprise a lower surface tension than that of the received source water, whereby the amended water may more readily spread over the surface, or surfaces, of one or more solid materials or particulates the amended water may come into contact with than the source water would. Accordingly, the amended water may be expected to more readily surround and coat any and all solid materials or particulates that it may come into contact with than the source water.
Referring to
As shown, the converging section 208 may be disposed proximal to the first inlet end 202 and the diverging section 212 may be disposed proximal to the outlet end 206. The throat section 210 may be interposed between the converging section 208 and the diverging section 212. In an embodiment, a flow of source water, which may be stored at or pumped to a positive pressure, may flow through the connector 200 from the first inlet 202 toward the outlet 204. This flow of source water may induce a pressure drop across the connector 200, substantially at the throat 210 of the connector 200, whereby additive fluid may be sucked into the connector 200 and combine with the source water flow. According to such an embodiment, source water may be disposed within the converging section 208, while both source water and additive may be disposed within the throat section 210. The source water and additive may mix within the connector 200 at the throat section 210 and within the diverging section 212, producing amended water which may be discharged from the connector at the outlet 204 and into the third conduit section 110.
In alternative embodiments to that shown, the connector 200 may comprise a configuration differing from the “back flow nozzle” configuration shown. In such alternative embodiments, a flow of additive fluid into the connector 200 may be affected by a pump, by gravity, or by any other suitable means for causing or inducing additive to flow from the additive supply 108 into the connector 200.
Turning back to
The valve 106 may allow for the composition of the amended water to be adjustable via either increasing or decreasing the relative amount of additive comprising the resultant amended water exiting the connector 200. During operation of the blasting apparatus 1000, therefore, an operator of the blasting apparatus 1000 may configure the amended water mixture to achieve a desired level of “spreadability” of the amended water, whereby an increase in the relative amount of additive within the amended water may be expected to cause a corresponding decrease in the surface tension of the amended water, increasing the “spreadability” of the amended water.
Referring to
In an embodiment, the third conduit section 110 may comprise a length of hose, tube, pipe, or the like and may comprise two open ends. The third conduit section 110 may comprise a plastic, metal, composite, or other material which may be suitable for receiving and routing received liquid. The third conduit section 110 may couple to the connector 200 at an inlet end of the third conduit section 110. The third conduit section 110 may be further configured to couple to the valve 112 at an outlet end of the third conduit section 110, whereby amended water may be routed from the connector 200 to the valve 112 (as indicated by the arrows shown in
As shown in
In an embodiment, the blasting apparatus 1000 may not be implemented with the valve 112 or, alternatively, the valve 112 may comprise a feature of another component of the blasting apparatus 1000, such as the discharge device 130, for example. According to such alternative embodiments, the third conduit section may be expected to couple with, and place in either in direct or indirect fluid communication with one another, the connector 200 and the discharge device 130.
Referring to the embodiment of
In an embodiment, the fourth conduit section 114 may comprise a length of hose, tube, pipe, or the like and may comprise two open ends. The fourth conduit section 114 may comprise a plastic, metal, composite, or other material which may be suitable for receiving and routing received liquid. The fourth conduit section 114 may couple to the valve 112 at an inlet end of the fourth conduit section 114. The fourth conduit section 114 may be further configured to couple to the discharge device 130 at an outlet end of the fourth conduit section 114, whereby amended water may be routed from the valve 112 to the discharge device 130 (as indicated by the arrows shown in
Amended water received at the discharge device 130 may be expelled from the discharge device 130, comprising a portion of a blast spray 140. The amended water may function as a containment agent of the blast spray 140, operating to spread over and saturate abrasive within the blast spray 140 as well as waste particulates which may be produced from blasting a work surface with the blast spray 140. These functions of the blasting apparatus 1000 and the amended water flowing within it are discussed in greater detail later in this specification.
As shown in
According to the embodiment of
In an embodiment, the fifth conduit section 118 may comprise a length of hose, tube, pipe, or the like. The fifth conduit section 118 may comprise a plastic, metal, composite, or other material which may be suitable for receiving and routing fluids at high pressures. The fifth conduit section 118 may comprise two open ends. The fifth conduit section 118 may couple to the pump 116 at an inlet end of the fifth conduit section 118. The fifth conduit section 118 may be further configured to couple to the valve 120 at an outlet end of the fifth conduit section 118, whereby pressurized air may be routed from the pump 116 to the valve 120 (as indicated by the arrows shown in
As shown in
In an embodiment, the blasting apparatus 1000 may not be implemented with the valve 120 or, alternatively, the valve 120 may comprise a feature of another component of the blasting apparatus 1000, such as the pump 116, for example. According to such alternative embodiments, the fifth conduit section 118 may be expected to couple with, and place in either in direct or indirect fluid communication with one another, the pump 116 and the discharge device 130.
According to the embodiment of
In an embodiment, the sixth conduit section 122 may comprise a length of hose, tube, pipe, or the like. The sixth conduit section 122 may comprise a plastic, metal, composite, or other material which may be suitable for receiving and routing abrasive, which may be in the form of very small particles of solid material. The sixth conduit section 122 may comprise two open ends. The sixth conduit section 122 may couple to the abrasive supply 124, which may comprise a length of pipe, a tank, reservoir, funnel or other suitable vessel for storing a solid material in small particle form, at an inlet end of the sixth conduit section 122. The sixth conduit section 122 may be further configured to couple to the valve 126 at an outlet end of the sixth conduit section 122, whereby abrasive may be routed from the abrasive supply 124 to the valve 126 (as indicated by the arrows shown in
In an embodiment, the abrasive stored within the abrasive supply 124 and directed to the valve 126 via the sixth conduit section 122 may comprise solid particles of between 20 to 350 Mesh sizes. In an embodiment, the abrasive may comprise garnet. In alternative embodiments, the abrasive stored within the abrasive supply 124 may comprise silica sand, magnesium sulfate, aluminum oxide, crushed glass grit, silicon carbide, plastic, pumice, steel shot or grit, baking soda, dry ice, or any other abrasive which may be suitable for use in blasting operations.
As shown in
The valve 126 position may be set, or adjusted, in response to one or more conditions within the work area, such as in response to one or more air quality parameters, one or more pressures of a fluid, or fluids, within the blasting apparatus 1000, or other sensed, detected, measured, or calculated parameter value. Additionally, or alternatively, the pressure setting may be set, or adjusted, using the valve 126 in response to one or more parameters of the abrasive used by the blasting apparatus 1000, such as the abrasive size, composition, flow rate, or the like.
In an embodiment, the blasting apparatus 1000 may not be implemented with the valve 126 or, alternatively, the valve 126 may comprise a feature of another component of the blasting apparatus 1000, such as the discharge device 130, for example. According to such alternative embodiments, the sixth conduit section 122 may be expected to couple with, and place in either in direct or indirect fluid communication with one another, the abrasive supply 124 and the discharge device 130.
Referring to
In an embodiment, the seventh conduit section 128 may comprise a length of hose, tube, pipe, or the like and may comprise one or more inlets and an outlet. The seventh conduit section 128 may comprise a plastic, metal, composite, or other material which may be suitable for receiving and routing the received mix of pressurized air and abrasive. The seventh conduit section 128 may couple to the valve 120 and the sixth conduit section 122, respectively, at inlets of the seventh conduit section 128. Further, the seventh conduit section 128 may couple to the discharge device 130 at an outlet of the seventh conduit section 128. Accordingly, a mix of pressurized air and abrasive may be received by the seventh conduit section 128 and may be routed to the discharge device 130 (as indicated by the arrows shown in
Referring to
In an embodiment, the discharge device 130 may comprise a component configuration for combining the received amended water, compressed air, and abrasive to generate the blast spray 140 for use in “wet” abrasive blasting operations. The received amended water and the received mixture of compressed air and abrasive may combine substantially within the nozzle 134 of the discharge device 130. The discharge device 130 may be configured to generate and expel the blast spray 140 from the nozzle 134 of the discharge device 130 at times when operator input is received from at the trigger 132 of the discharge device 130.
Importantly, the blast spray 140 generated may comprise low surface tension, due to the use of surfactant within the amended water, allowing for greater surface contact between the amended water and solid materials with which the amended water may come into contact. The blast spray 140 may exit the nozzle 134 as a vapor mist within which the abrasive media is contained. As such, the abrasive may be substantially surrounded by, and saturated with, amended water which may comprise a fine mist or vapor. The blast spray 140 may be directed by an operator of the blasting apparatus 1000 toward a work surface for removing one or more surfacing materials from the work surface. The surfacing material, whether toxic or non-toxic, may be dislodged from and removed from the work surface, with the abrasive media and dislodged surfacing material substantially surrounded and saturated by the amended water mist of the blast spray 140.
The blasting apparatus 1000 may be used in accordance with the method 400, shown in
Referring to
At the step 402, the blasting apparatus 1000 may be configured for use as part of a wet blasting operation. Configuration of the blasting apparatus 1000 may comprise connecting the blasting apparatus to a water supply, to a surfactant supply, and to a blast media supply as described, above, and as shown in
At the step 404, one or more valves of the blasting apparatus 1000 may be set to desired initial settings to configure the blast spray to be generated using the blasting apparatus 1000. In an embodiment, each of the valves 106, 112 may be set to configure the relative composition of the amended water portion comprising the blast spray. Additionally, the valves 120, 126 may be set to provide the blast spray with the desired amount of abrasive as well as to set the pressure value for compressed air to be utilized by the blasting apparatus 1000. Additionally, at the step 404, the pump 116 may be energized.
At the step 406, an operator may begin wet blasting one or more work surfaces to remove the surfacing materials. The wet blasting operation may generate waste materials as surfacing material, or materials, are dislodged from the work surface. In instances where the waste materials may be toxic, one or more air quality parameters in and around the work area may be monitored using known, or proscribed, methods. For example, in an asbestos abatement operation, air quality in and around the work area may be monitored, or checked, through use of phase contrast microscopy to ensure that PELs, as defined in any and all applicable health and safety standards are not exceeded.
As needed, at the step 408, one or more configuration parameters of the blasting apparatus 1000, such as the positions of one or more valves, may be adjusted in response to results air quality monitoring. For example, if air monitoring reveals that exposure levels in and around a work area during a wet blasting operation to remove asbestos from a work surface are approaching, or exceed, a defined PEL, the operator may respond by opening the valve 106 to increase the surfactant within the amended water supply. This may further decrease the surface tension of the amended water within the blast spray, promoting greater saturation of any and all waste produced by the wet blasting operation, thereby reducing or eliminating any waste dust generated. Additionally, or alternatively, the operator may decrease either or both of the abrasive supply via the valve 126, or the air pressure via the valve 120 to decrease the relative amount of abrasive forming the blast spray.
If no unsafe condition is found at the step 408, the operator may continue wet blasting operation in the current configuration until the abatement activity is completed. Alternatively, if no unsafe condition is found at the step 408, the operator may return to the step 406 and continue wet blasting operation in the current configuration for a predetermined amount of time before returning to the step 408 to again check the air quality within an around the work area. In an embodiment, the amount of time may be thirty minutes or, alternatively, an amount of time proscribed by an applicable health or safety regulation.
Advantageously, asbestos abatement using the blasting apparatus 1000 and in accordance with the method 400 may provide the advantages of providing for rapid asbestos abatement while avoiding production of airborne waste within and around the work area. Further, the apparatus and method described, herein, may provide for a wet blasting method of asbestos removal in which the wetting agent as well as the abrasive may be delivered to the work surface via a single discharge device operated by a single operator. The apparatus and method described, herein, may also provide for easier clean up following an asbestos abatement activity since the waste produced comprises a liquid waste product comprising removed surfacing material and abrasive substantially saturated with amended water rather than solid waste product in the form of surfacing material dust.
In an exemplary execution of the method 400, for example, an embodiment of the blasting apparatus 1000 described above may be utilized in a wet blasting operation to remove residual fireproofing, containing asbestos, as well as glue form a corrugated ceiling deck in compliance with the regulations of 29 CFR §1926.1101. As a precondition to the commencement of wet blasting, the work area and operators may be prepared in compliance with all applicable regulations, including the work area being isolated from the surroundings by plastic membranes, creation of a negative pressure environment within the work area in which air from the work area may be forced through HEPA filters, and donning of respirators and protective clothing by the operators.
The blasting apparatus 1000, which may comprise an IBIX 25 H2O Blasting System, may be connected to a water source via a hose. The blasting apparatus 1000 may be implemented with a Venturi style connector and a flow control valve which may be placed in fluid communication with the water supply. The connector may access a surfactant supply and may be configured to induce flow of surfactant into the connector while source water is flowing through the connector to produce amended water.
The blasting apparatus 1000 may be implemented with an IBIX HELIX Blast Gun and a 7/32″ nozzle. A compressor may be operatively connected to an abrasive supply, which may comprise garnet, and also operatively connected to the Blast Gun to deliver the abrasive and compressed air to the Blast Gun.
The water source and Venturi may be configured to supply amended water to the Blast Gun at 1.5 gallons/hour through setting of flow control valves. The abrasive media supplied to the Blast Gun may be set to a rate of 110 pounds per hour through setting of flow control valves. A single operator may operate the Blast Gun to direct the resultant blast spray at the corrugated ceiling to remove the residual fireproofing and glue. During blasting operation, the air quality and exposure levels of operators within the work zone, as well as in the surrounding areas, may be monitored in accordance with the PCM method with samples taken after thirty minutes of blasting and after approximately eight hours of blasting.
According to such an exemplary operation, the wet blasting operation may yield a production rate well above that other methods, such as grinding, while not exposing the operator to asbestos fibers at above the PELs defined by 29 CFR §1926.1101. Details of such an exemplary execution of the method 400 using an embodiment of the blasting apparatus 1000 are documented and provided as Appendices A-C of this specification.
Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of other features. Many such variations and modifications may be considered desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments.
