Abstract:
A device is disclosed which acts to contain the contaminated effluent of an operation such as a hydro-blasting operation. The device has flexible bag for containing the effluent. The bag has an opening interfacing with a vessel being fluid blasted, into which opening the blasting effluent is received. A drain port is positioned on the containment bag to gravity empty the effluent from the interior of the bag, and a vent appropriately located on the containment bag to relieve pressure in the interior space during use and emptying. A flange strap disposed secures the bag opening to the vessel, and a support means is arranged to suspend the containment bag in proper relationship with the vessel. An expansion mechanism can be used to hold the containment bag in an expanded condition to facilitate use of the bag to properly contain the effluent.

Description:
The present application claims the benefit of prior filed U.S. Provisional Patent Application, Ser. No. 60/727,783 filed 18 Oct. 2005, to which the present application is a regular U.S. national application. 

   FIELD OF THE INVENTION 
   The present invention is in the field of apparatuses for cleaning via fluid contact with solids to remove adherent foreign matter from the internal surfaces of hollow work. More specifically, the present invention relates to a transportable device for collecting the effluent from the treatment of conduits with pressurized fluids. 
   BACKGROUND OF THE INVENTION 
   In the petrochemical plant industry, it is regularly necessary to clean various conduits and vessels to remove any accumulating buildup on their interior surfaces. This buildup can comprise constituents of the content of the conduit in addition to foreign matter depositing onto interior surfaces. To clean contaminated conduits and vessels often requires shutting down the associated production line and at least partial disassembly of the conduit or vessel being cleaned. A typical cleaning method is to use a pressurized and heated fluid stream to dissolve or dislodge the accumulation from the solid interior surfaces of the vessel. Hydro-blasting is one such typical pressurized fluid stream cleaning method where the vessel (e.g., a heat exchanger) is opened at both ends and the interior is hydro-blasted from one open end while the fluid effluent, usually still under some pressure, emerges from the other open end. However, because the liquid effluent can be contaminated with toxic materials, the effluent from the operation must be collected and properly disposed of as a toxic waste stream. Often it is not possible to contain the effluent at the location of the vessel, and the vessel must be disassembled further and the internal components moved to another more appropriate site to perform the hydro-blasting operation. This additional disassembly and removal of vessel components increases down time and cost of the cleaning operation. It would be useful in the field to have a means to reduce the number of situations in which it is necessary to disassemble the vessel being serviced to remove the components to be cleaned. 
   The industry has long recognized aspects of this problem and has been motivated to find solutions to them. For example, Tiegs et al. (U.S. Pat. No. 4,950,392) disclose an apparatus for removing contaminates from a caustic washing solution. The device of the Tiegs et al. patent comprises a filtration tank housing a pump. The pump has a filter bag disposed on its outflow which collects particulates. However, the Tiegs et al. device does not collect all of the effluent, only the particulates. Also, the Tiegs device cannot be used in place, for example, on the opening of a refinery heat exchanger vessel. Additionally, the Tiegs device requires a pump. As another example, Mallow, Sr. et al. (U.S. Pat. No. 5,725,009) disclose a device for containing and redirecting fluid from a down-fitting on a section of a pipe. The device of the Mallow, Sr. et al. comprises a bag with an opening in its top for attaching to the down-fitting of a pipe. After placement over the down-fitting, the cover to the fitting is removed. When the Mallow, Sr. et al. device is practiced, the bag is vertically suspended from the fitting. However, the Mallow, Sr. device cannot be used in a horizontally to attach to an end fitting or an inline fitting. Therefore, it would be further useful in the field to have a device that can collect all of the effluent, and that can be used in place on a vessel or pipe end fitting or inline fitting. 
   SUMMARY OF THE INVENTION 
   The present invention is a device for containing the outflow of waste material from a vessel, the interior of which vessel is being cleaned using a hydro-blasting or similar pressurized fluid jet process. More specifically, the present device is useful to contain the effluent of such process that otherwise would be discharged into the environment as a pollutant. Examples of such vessels anticipated by the present invention include heat exchangers and pipe conduits used in petrol-chemical refineries. 
   The present fluid blasting effluent containment device mounts horizontally inline with a vessel&#39;s end fitting or inline fitting. The present invention is useful to contain the contaminated effluent of an operation such as a hydro-blasting operation. Containment as anticipated by the present invention means direct streams of liquid, as well as liquid splash and aerosol. The device has a flexible containment bag for receiving and holding the liquid effluent of a fluid blasting operation. The containment bag has an opening interfacing with the vessel being fluid blasted, into which opening the blasting effluent is received. A drain port is positioned on the containment bag so that the contents can be gravity emptied from the interior of the bag. The present invention is a passive device, and requires no mechanization to accomplish its purpose. 
   A vent is appropriately located on the containment bag to relieve pressure in the interior space during filling, and emptying. The vent can include an aerosol or vapor collector, to prevent or reduce the escape of vapors during collection of the effluent. A flange strap disposed proximate the bag opening is used to seal and secure the bag opening to the vessel, and a support means is arranged to hold or suspend the containment bag in proper relationship with the vessel. An expansion mechanism can be used to hold the containment bag in an expanded condition to facilitate use of the bag to properly contain the effluent. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a representation of the present fluid blasting effluent containment device of the present invention. 
       FIG. 2A  is a side elevation view representation of the present blast containment device installed on a heat exchanger type vessel at its end fitting, and its horizontal configuration. 
       FIG. 2B  is a top plan view of a representation of the present blast containment device installed on a heat exchanger type vessel at an “inline” type end fitting. 
       FIG. 3  is a perspective view of a representation of the present fluid blasting effluent containment device showing an opening in the bag of the device which is smaller than the cross-section of the interior space of the bag. 
       FIG. 4  is a perspective view of an alternative cross-sectional configuration of the interior space of the bag of the present containment device. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the drawings, the details of preferred embodiments of the present invention are graphically and schematically illustrated. Like elements in the drawings are represented by like numbers, and any similar elements are represented by like numbers with a different lower case letter suffix. 
   As illustrated in  FIGS. 1 ,  2 A and  2 B, the present blasting fluid effluent containment device  10  comprises a flexible containment bag  14  having support attachment points  30  for suspending the bag in place at one open end  62  of a vessel  60  being fluid blasted. The containment bag  14  has a bag opening  22  for interfacing with the open back end  62  of the vessel  60  opposite the operations or front end  64  of the vessel  60  where the fluid jet  66  is being introduced into the vessel  60  (see  FIG. 2 ). A flange strap  28  is disposed proximate the bag opening  22 . The flange strap  28  provides a means to securely cinch bag  14  against the very end of the vessel  60  being fluid blasted to secure the bag opening  22  of the containment bag  14  to the vessel  60 . The throat portion  24  of the bag opening  22  is drawn closed at it leading edge  23  around the circumference of the vessel  60 . This traps any leakage and provides added security should the flange strap  28  slip. A benefit of the horizontal aspect of the present invention is that the full cross-section of the fitting in line with the flow of the vessel is open directly to the interior of the bag  14 , and back pressure that otherwise may be present is reduced. 
   The attachment points  30  are disposed on the exterior wall  32  of the containment bag  14  to provide a mechanism to connect a means (not shown) of suspending the containment bag  14  to have the bag opening  22  in a proper relationship with the open end  62  of the vessel  60 , as illustrated in  FIG. 2 . The proper relationship allows the effluent flowing from the open back end  62  of the vessel, whether as a fluid stream or as a vapor cloud, to pass through the bag opening  22  and be collected and contained in the interior space  26  of the bag  14 . Additionally, as shown in the figures, an expansion means  44  is provided to hold the containment bag  14  in an expanded condition to facilitate collecting the effluent in the interior space  26  of the bag  14 . 
   Effluent collected in the interior space  26  of the containment bag  14  is drained from the bag  14  via a drain port  36  disposed in the bag wall  32  proximate the bottom of the interior space  26 . A vent  40  is also provided, and is disposed in the bag wall  32  proximate the top of the interior space  26 . The vent  40  relieves any pressure positive or negative) buildup that may tend to accumulate in the interior space  26  of the bag  14 . Because the interior space is intended to be proximately at atmospheric pressure, an expansion means  44  is provided to hold the containment bag  14  in an expanded condition during use. This additionally helps to minimize back pressure that otherwise may be present. 
   In a preferred embodiment as illustrated in the figures, the bag  14  of the present blasting fluid effluent containment device  10  is made of a flexible material and is water impermeable. Preferably, the containment bag  14  is made of a flexible, reinforced, rubberized material. The material should be proof against the expected composition of the effluent it is intended to contain. For example, a neoprene coated reinforced fabric is readily available and useful for many applications of the present device  10 . Other suitable bag materials are known to and are selectable by one of ordinary skill in the art for practice in the present invention. 
   In the preferred embodiment illustrated in  FIGS. 1-3 , the containment bag  14  is substantially cylindrical and mounted horizontally along its axis, in line with the open end  62  of the vessel  60 . Although the containment bag  14  is exemplified with the interior space  26  as having a substantially circular cross-section, other cross-sectional configurations of the interior space  26  are practicable in the containment device as well. For example,  FIG. 4  illustrates an alternative embodiment of the present containment device wherein the interior space  26   a  of the bag  14   a  has a substantially triangular cross-section. Additionally illustrated in  FIG. 4  is a expansion plate  48 , which is used to hold the interior space  26   a  of the containment bag  14   a  in an expanded condition. A expansion plate  48  may be disposed on the inside of the bag  14   a  in the interior space  26   a , on the exterior wall  33  of the bag  14   a , or both. It is an intended feature of whatever expansion means is utilized in practicing the present device  10 , that it not prevent the containment bag  14  from being collapsible to facilitate its storage. A support rod  46  may be used either inside or outside a containment bag  14   a  to facilitate supporting the bag  14   a  along a length parallel to its axis  20 . Once effluent is collected in the containment bag  14 , it is removed via the drain port  36 . In the preferred embodiments illustrated, a gravity drain was used to drain the blasting effluent from the interior space  26  of the containment bag. That is, the drain port  36  was disposed on the containment bag  14  to gravity empty the effluent from the bag&#39;s interior space  26 , as opposed to using an active or driven emptying means (e.g., a pump). 
   The vent  40  is disposed on the containment bag  14  to relieve any pressure that may develop in the interior space  26  of the bag  14  during use. Because the pressure condition of the effluent as it exits the back end opening  62  of the vessel  60  can be variable (i.e., passive flow, driven flow, pressurized stream, vapor cloud), absent a venting mechanism positive pressure may develop in the bag&#39;s interior space  26  and cause a back pressure on the effluent. The vent  40  is intended to alleviate this. Additionally, it is possible in certain circumstances that the draining process could create a negative pressure in the bag, causing the walls of the containment bag to collapse and reducing the empty volume of the interior space  26 . The vent  40  is also intended to alleviate this condition if it is a problem. Because there is the likelihood the effluent will comprise a vapor component, it is preferred that the vent  40  include a vapor trap (not shown) to reduce or eliminate emission of contaminated and/or hazardous chemical vapors from the device  10 . Vapor traps are know to and selectable by one of ordinary skill in the art for practice in the present invention. Examples of such traps include absorption traps make of porous meshes, fibers and other high surface area materials disposed between the interior of the bag and atmosphere, to provide a collection surface for the vapors. Optionally, the vent  40  may be configured to be closeable. 
   As exemplified in  FIG. 3 , bag opening  22  of the present fluid blasting effluent containment device  10  does not have to comprise the entire cross-section of the interior space  26  of the bag  14 . In  FIG. 3 , the bag opening  22  is smaller than the cross-section of the interior space  26  of the bag  14 , but the plane of the bag opening  22  is still substantially perpendicular to the horizontal axis  20   a  of the bag  14 . Also, as illustrated in  FIG. 3 , the containment bag front  52  may be separable from the rest of the containment bag  14 , and attachable by such means as a zipper  54 . A removable bag front  52  allows use of different sized bag opening  22  to be used in the same containment device  10 . 
   In a preferred embodiment, the containment device  10  comprised a cylindrical bag  14  about four feet long and made from a poly nylon reinforced fabric membrane. Preferably, the membrane is from 12 to 80 mil thick. The bag opening  22  was the full cross-section of the interior space  26  and had a draw string  27  at the leading edge  23  of the bag opening  22 . The flange strap  28  was proximate the bag opening  22 , but set back from the leading edge  23 . The portion of the bag opening  22  between the leading edge  23  and the flange strap defined the bag throat  24 . In a preferred embodiment, the device had support bands on two foot centers along its axial length that served as expansion means  44 . In the cylindrical bag embodiments, each support band  44  had at least one pair of metal rings off set at 45 degrees from what would be the top of the interior space  26 . The metal rings served as the attachment means  30  for the containment device  10 . Additionally, there can be an optional overflow drain  70  disposed about 45 to 60 degrees radially from the drain port  36 . The overflow drain serves as a backup or secondary drain if the effluent level in the interior space  26  of the bag  14  becomes too high. 
   In using the device  10 , the bag throat  24  was passed over the flange  64  at the open end  62  of the vessel  60 . The flange strap  28  was tightened to closely engage the bag throat  24  around the flange  64  and seal the interior space  26  of the containment bag  14  to the vessel  60 . The draw string  27  at the leading edge  23  of the bag opening  22  was also tightened to closely engage the leading edge  23  of the bag throat  24  with the vessel  60 , to provide a secondary seal. If desired, a secondary drain (not shown) may be disposed in the opening throat  24  of the containment bag  14  to drain any effluent that may leak past the primary seal at the flange strap  28 . 
   While the above description contains many specifics, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of one or another preferred embodiment thereof. Many other variations are possible, which would be obvious to one skilled in the art. Accordingly, the scope of the invention should be determined by the scope of the appended claims and their equivalents, and not just by the embodiments.