Abstract:
An inflatable conduit plug is used to seal a conduit such as a floor drain or an air vent. The conduit plug includes a shroud that is removably sealed within the conduit so that fluids pass through the shroud opening. Axially disposed within the shroud is an inflatable bladder adapted for closing the shroud opening. The inflatable bladder is inflated by an inflation signal generated by a controller upon receipt of a contamination signal received from a remote contamination detector. The plug operates in a wireless environment and can be controlled remotely. The plug can also be adapted for diverting contamination away from sensitive lands and storm drains.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to devices for closing conduits against fluid flow and in particular relates to an inflatable fluid conduit plug adapted to stop the flow of contaminants into a fluid conduit. 
       BACKGROUND 
       [0002]    Industrial processes often leak fluids in liquid and gaseous state that are contaminants and pose a threat to the natural environment. These discharges may be the on-going byproduct of a process or they may be the result of an accident such as operator error, a fire or an explosion. Either way, it is imperative that these contaminants not be allowed to enter natural water flows or the atmosphere. Industrial facilities have a large number of access conduits to the natural environment such as floor drains and exhaust stacks and vents. These conduits are permitted to discharge fluids into the natural environment either in a non-contaminated state or at permissible contamination thresholds established by law. Beyond these thresholds, the contaminated discharges are not environmentally benign and are unlawful under environmental laws and regulations. Therefore, there is a need to maintain control over discharge of contaminated fluids into the natural environment by ensuring that fluid conduits can be closed before contaminated fluids can pass through them. 
         [0003]    Industry relies upon a variety of apparatus and methods to control or prevent contaminated fluid discharges. Absorbents may be used to absorb contaminants spilled onto a surface. However, this is often “after-the-fact” and will not stop contaminants from entering a drain. Ventilation dampers may close upon a leak of contaminated fluid but the dampers may not seal the conduit entirely and may be too slow to adequately respond to a large release of contaminants. Closure valves can be inserted into fluid conduits downstream of drains to prevent the discharge of contaminated fluids. However, these valves may failure to close due to mechanical problems or close too slowly to prevent leakage. In many industrial facilities the valves can only be actuated by a human operator and this type of procedure has its own innate unreliabilities and deficiencies. 
         [0004]    Therefore, there is an on-going requirement to automatically, swiftly and reliably close fluid conduits that have access to the natural environment before any contaminant can reach the natural environment. 
       SUMMARY 
       [0005]    In accordance with an embodiment of the present invention there is provided an apparatus, namely, an inflatable fluid conduit plug adapted to close fluid conduits that may expel contaminants to the natural environment. Examples of such fluid conduits include floor drains and exhaust stacks and vents. The conduit plug comprises a shroud for sealed insertion into the conduit. Within the shroud is disposed an inflatable bladder adapted for closing the shroud opening upon a bladder inflation signal. The bladder is inflated by a suitable fluid which is generally a gas such as carbon dioxide or nitrogen. The gas is contained in a pressurized reservoir such as a gas cartridge or cylinder which is housed within the apparatus. The apparatus is designed to be self-contained, that is, with on-board gas and power sources so that it is able to function without the need for external connections to gas or electrical conduits. The conduit plug includes contaminant detection means for generating a contaminant signal and a controller for receiving the contaminant signal and transmitting an inflation signal. The inflation signal will open the pathway between the gas reservoir and the bladder thereby inflating the bladder. The pathway between the gas reservoir and the bladder may be closed using a diaphragm which is subsequently punctured by a pin during an inflation signal. Alternatively, the pathway may be closed using a quick-open valve. The shroud is shaped to have the same contour as the conduit so that the shroud can be inserted axially into the conduit and sealed against the walls of the conduit. In this manner, fluids will flow through the shroud opening and can be blocked by bladder inflation. 
         [0006]    The bladder is fabricated from a suitable chemically resistant material. It is disposed axially within the shroud and supported by bracing rods extending from the inside surface of the shroud. The bladder is adapted to inflate rapidly to prevent contaminant leakage through the shroud opening. The bladder may be equipped with an accelerometer for monitoring inflation speed and an alarm for alerting an operator when the inflation speed is sub-optimum. 
         [0007]    In another embodiment of the invention there is provided a plurality of inflatable dams that are adapted for ground spill diversion and storm/sewer drain diversion. The dams are fabricated as inflatable bladders with automatic inflation means comprising a pressurized gas reservoir electrical power source and inflation signal receiver. Such dams can be employed around sensitive environmental zones around an industrial site or around storm/sewer drains within an industrial site such as on a roadway or parking lot. Should a spill occur on a surface such as a roadway, the dams can be activated by chemical sensors before the spill reaches a drain. The dams can also be actuated remotely upon a wireless signal. 
         [0008]    Returning to the plug embodiment of the invention, contaminant sensors may be disposed within the shroud opening or remote from the plug. The contaminant sensors are adapted to permit an uncontaminated fluid flow into the shroud but they will generate an inflation signal when fluid flow contains a contaminant. An inflation signal can also be generated by an operator from a remote location by wireless means. 
         [0009]    The plug further comprises an electrical circuit comprising a battery for powering a micro-processor. The micro-processor comprises a voltmeter for monitoring battery output, a low voltage alarm for alerting an operator, a pressure gauge for monitoring pressure within the bladder, a low pressure alarm for alerting the operator, an electrically actuated inflation valve between the bladder and the reservoir and an alarm for alerting the operator of valve actuation. The micro-processor is further adapted to receive a contaminant detection signal from a contaminant sensor and transmit an inflation signal to the electrically actuated inflation valve. The sensors may be programmable for detection of a plurality of contaminants. The micro-processor may be programmable for a plurality of contaminant threshold values. The micro-processor can send and receive data and commands over an encrypted wireless network. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  shows a cross-section of one example of an embodiment of the invention as it might appear inserted into a floor drain. 
           [0011]      FIG. 2  shows a cross-section of the same example of the embodiment of the invention as shown in  FIG. 1  removed from the floor drain. 
           [0012]      FIG. 3  shows the flange arrangement of yet another example of an embodiment of the invention in perspective cross-sectional view. 
           [0013]      FIG. 4  shows one example of an embodiment of the invention in an inflated state. 
           [0014]      FIG. 5  shows another embodiment of the invention. 
           [0015]      FIG. 6  shows yet another embodiment of the invention. 
           [0016]      FIG. 7  shows a schematic of one example of an embodiment of the invention. 
           [0017]      FIG. 8  shows a schematic of a network of embodiments of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Inflatable Conduit Bladder 
         [0019]    Referring to  FIGS. 1 ,  2  and  3  there is shown a cross-section of one example of the invention  10  which is an inflatable fluid conduit plug comprising a shroud  12  for sealed insertion into the conduit  14 . One advantage of this example is that since many drain conduits have worn and damaged surfaces, the shroud ensures that the bladder  16  is able to inflate in a fluid-sealed configuration against the smooth shroud surface and not the irregular surface of a damaged conduit. This ensures that the conduit is not further damaged by the inflating bladder and that the bladder is not punctured by an irregular surface. Therefore, existing infrastructure can be used with the invention without having to replace worn conduits. The inflatable bladder  16  is disposed within the shroud  12  for closing the shroud opening  17  upon receipt of an inflation signal from the controller  22 . The bladder inflation means shown generally as  18  comprises a cylinder or reservoir of compressed gas  70 , a valve  62 , a DC power supply  25 , typically a battery, and controller  22 . The reservoir of compressed gas  70  is in fluid communication with the bladder  16 . Contaminant detectors  74  can be located throughout the industrial site and generally anywhere that contaminants need to be detected. The detectors are in wireless communication with the controller as shown by the dotted lines and generate a contaminant signal  20  that is received by an RF receiver located within the controller  22 . The controller will process the contaminant signal  20  into an inflation signal  24  ( FIG. 2 ) which is received by valve  62 . Valve  62  will then open and pressurized gas will inflate the bladder thereby closing the shroud opening  17 . 
         [0020]    The shroud  12  has a top  26  and a bottom  28 , an inner surface  30  and an outer surface  32 . The outer surface is congruent with and adapted to complement the shape of the inner conduit wall  34 . For example, a floor drain is generally circular and a storm drain is generally square. The shroud can be adapted to fit both types of conduit. By using a shroud inside the conduit there is no need to replace the conduit prior to installing my invention. The shroud will bear the force of bladder inflation and not further damage older conduits. The shroud  12  is further adapted to extend a predetermined distance  36  into the conduit  14  to ensure adequate sealing when inflated. Shroud  12  is disposed axially  38  within the conduit  14  and inflation pressure generated by the bladder when in contact with the shroud inside wall  30  should be equal around the circumference of the shroud wall  30 . The shroud  12  outer surface  32  is in such positional agreement with the inner wall  34  of the conduit  14  that there is a narrow annulus  40  formed between them. The annulus  40  is sealed fluid tight with sealing means  42  at the shroud top  26  thereby achieving a shroud sealed insertion and fixing the plug within the conduit in a removable manner. Sealing means  42  can be any suitable sealing compound as long as it is chemically resistant. 
         [0021]    In the example shown in  FIGS. 1 and 2 , there is illustrated a flange  44  extending flush from the top  26  of the shroud  12 . The flange  44  is adapted to suspend the plug  10  from a surface  46  such as a floor where the plug is inserted into a floor drain. In  FIG. 1  the flange  44  is shown slightly elevated above the floor for illustrative purposes but would sit on the surface  46  when installed. The flange can also be used as an adhesive or fastening surface to adhere the plug in an upside-down configuration to a suspended surface such as when the plug is mounted into a ventilation duct within a roof or ceiling surface. 
         [0022]    In the same example as shown in  FIGS. 1 and 2 , the plug may be supported from inside  14  a conduit by a member  48  depending from the bottom  50  of the inflation means housing  60  to a supporting surface  52  within the conduit. The member may also be adjustable to suit a variety of conduit depths. 
         [0023]    The bladder  16  is fabricated from a suitable chemically resistant material such as Tyvec®, Tychem® or polyurethane. 
         [0024]    Referring to  FIG. 2 , there is shown plug  10  in cross-section outside of the drain. The bladder  16  is disposed axially within the shroud  12 . The bladder has a top  54  and a bottom  56  end and is fixed in place to the inner surface of the shroud by bracing rods  58  extending from the top and bottom of the shroud top inner surface  30 . 
         [0025]      FIG. 3  illustrates the same example  10  as in  FIG. 2  in a perspective cross-sectional view to better illustrate the bracing rods  58  between the bladder top  54  and bottom  56  and the inner surface  30  of the shroud  12 . 
         [0026]    The bladder  16  is threadably connected to the inflation means housing  60  by valve  62  to which gas reservoir  70  is also threadably attached. Valve  62  may be a firing pin which ruptures a diaphragm on the top of the gas reservoir in order to inflate the bladder. In another example of the invention, and as noted below, the bladder  16  further comprises an accelerometer  33  ( FIG. 2  and  FIG. 7 ) for detecting inflation speed and an alarm  31  for alerting an operator  68  when the inflation speed is sub-optimum. The suitable inflation fluid is usually a gas but other inflation media can be used such as foam or a liquid. 
         [0027]    Contaminant detectors  74  are sensors adapted to permit a desired fluid flow such as clean water or clean air into the shroud opening  17 . When contaminants are detected by the sensor  74  a contaminant signal  20  is generated (dotted line). This will trigger an inflation signal  24  and actuate the bladder  16  within the shroud opening  17 . In one example of the invention illustrated in  FIG. 2 , the contaminant sensor  74  is disposed at the top of the shroud opening  17  so a contaminant signal  20  will be generated as soon as the contaminant contacts the top of the shroud opening. This is illustrated as a detection band  74  ( FIG. 2 ) around the inside surface of the shroud. Such detectors are well known in the art. The contaminant signal is received wirelessly by the controller  22  which in turn generates the inflation signal  24 . In another example of the invention the contaminant sensor  74  is disposed remote from the conduit  14  so that a contaminant signal  20  and a subsequent inflation signal  24  are generated prior to the contaminant entering the conduit. In yet another example of the invention, the inflation signal  24  may be generated independent of a contaminant signal and manually by an operator  68  from a remote location. In all examples, the contaminant sensors are comprised of contaminant sensing means, a RF signal emitter and power source so that they may operate independently and remotely from the plug. The RF signal emitted by the contaminant sensors are received by the controller&#39;s RF receiver and processed. 
         [0028]    Referring now to  FIG. 4 , there is shown the plug  10  having bladder  16  in an inflated state. In this configuration the bladder  16  is shown having a circular shape. It could have other shapes as well to suit the shape of the conduit in which the device is inserted. There is also illustrated contact area  17  between the bladder and the inner wall  30  of the shroud  12 . Depending on the application this contact area  17  can be adjusted to ensure a fluid seal in the conduit. 
         [0029]    Inflatable Diversion Bladder 
         [0030]    Referring now to  FIG. 5  there is shown another example of the invention  200  where the inflatable bladder  202  is used to form a diversion obstacle, dam or berm to divert contaminants away from a sensitive ecological area  204  such as outside yards or lawns. The area may be surrounded by an array of contaminant detectors  206  that is in wireless communication  210  with the control  170  ( FIG. 8 ) and in wireless communication  212  with the bladder  202  so that when a contaminant is detected an alarm is sounded at the control for the operator and an inflation signal is  212  is sent to the bladder. 
         [0031]    Referring now to  FIG. 6  there is shown another example of the invention  220  where the diversion bladders  222  surround a drain  224  such as might be found in a parking lot or on a street to divert contaminants away from the drain. The drain may be surrounded by an array of contaminant detectors  226  that are in wireless communication  230  with the control  170  ( FIG. 8 ) and in wireless communication  232  with the bladders  222  so that when a contaminant is detected an alarm is sounded at the control for the operator and an inflation signal is  232  is sent to the bladder. 
         [0032]    Method of Operation of a Network of Conduit Plugs 
         [0033]    Referring now to  FIG. 7  there is shown a schematic diagram of the control scheme used in one example of the invention. The contaminant sensor  74  can be located anywhere required to detect a contaminant. The sensor typically comprises a sensing element  75 , a battery  77  and a RF emitter  79 . When a contaminant is sensed by the sensor the sensor triggers the emitter and a contaminant signal  20  is relayed by antenna  81  to the RF receiver  83  located in the controller  22  housed within housing  60 . The controller is typically a micro-processor and the RF receiver is contained within the circuit of the micro-processor. The micro-processor is also adapted to receive a signal  31  from the accelerometer  33  if the bladder does not inflate properly, a signal  36  from a pressure sensor  37  within the bladder if the bladder pressure is deficient or declining after inflation, a signal  39  from a pressure sensor  41  in the gas reservoir if the pressure is inadequate, a low voltage signal  43  from a low voltage sensor  45  on the battery  25 . 
         [0034]    In the event of any alarm condition detected by the micro-processor a RF signal  88  is sent to the operator  68  and a suitable alarm is annunciated on a remote control panel so that corrective action can be taken. In one example of the invention the contaminant sensors are programmable for detection of a plurality of contaminants. In another example of the invention, the micro-processor is adapted to generate an inflation signal for a plurality of contaminant threshold values. 
         [0035]    Referring now to  FIG. 8  there is shown a mesh network  150  of plugs arranged in a large industrial facility  154  which might comprises a plurality of liquid drain conduit plugs  156  and gaseous ventilation conduit plugs  158 . The plugs  156  and  158  are arranged in zones wherein each zone contains a predetermined number of conduit plugs. The conduit plugs of each zone are in wireless communication  161  with a zone repeater  160 ,  162 ,  164  and  166 . The zone repeaters are in wireless communication with a control unit  170 . The zone repeaters and the control unit are located remote from the plugs. The zone repeaters are located within the industrial facility and arranged in such a manner that each plug is in wireless communication with at least one repeater. As indicated in  FIG. 8 , the plugs can be in wireless communication  172  with more than one repeater for redundancy purposes. The control is in wired or wireless communication with a PC  174  that will receive the various alarms described previously and alert  88  the operator as to their presence for remedial action. The operator can also use the PC to inflate different groups of plugs as required or disable groups of plugs for maintenance. The plugs can also be monitored from a remote location  180  in wired or wireless communication with the control unit  170 . A portable device  182  such as a cell phone or a portable computing device can be used to receive alarms  184  and initiate inflation of all or particular plugs. 
         [0036]    A method of operating a network of inflatable conduit plugs comprises the steps of:
       1. Installing a plurality of conduit plugs in a plurality of fluid conduits;   2. Installing a suitable number of contaminant detectors in RF communication with each conduit plug of said plurality of conduit plugs;   3. Grouping a predetermined number of the plurality of conduit plugs into an operational zones;   4. Connecting said predetermined number of conduit plugs in each of said operational zones by way of RF communications to an operational zone repeater;   5. Connecting each of said operational zone repeaters by way of RF communications to a network controller; and,   6. Providing said network controller with a user interface.       
 
         [0043]    Each of the operational zone repeaters can be connected to at least one other operational zone repeater for redundancy communications to the network controller. 
         [0044]    The user interface is comprised in a computer and is programmed to identify the location and operational status of each inflatable conduit plug, zone repeater and contaminant detector. 
         [0045]    The method operation further includes the step of providing RF remote communication between the user and the network controller by way of a portable device. 
         [0046]    The network controller can communicate by communication means to remote controllers for remote control of the network. 
         [0047]    Although the description above contains much specificity, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents.