Abstract:
A method and apparatus for exhausting steam in steam curing a cured-in-place liner that avoids directing the steam toward a house or building in communication with a pipeline in need of repair. One embodiment includes the use of a liner, a bladder, and an exhaust hose operatively connected to the bladder. A resinous material capable of curing and hardening is applied to the liner. The bladder presses the liner against the pipeline. The end of the steam exhaust hose connected to the bladder is positioned on the interior of the bladder and the opposite end of the steam house is positioned outside the bladder to direct steam away from the house or building as steam is introduced inside the bladder to assist in curing the resinous material.

Description:
[0001]    This application is based upon U.S. Provisional Application Ser. No. 62/133,792 filed Mar. 16, 2015, the complete disclosure of which is hereby expressly incorporated by this reference. 
     
    
     BACKGROUND 
       [0002]    The invention relates generally to a device and method for repairing a pipe or other underground structure, such as an underground sewer pipe in communication with a house or building. More particularly, but not exclusively, the invention relates to a method of exhausting steam in steam curing a cured-in-place liner that avoids venting or directing steam toward the house or building. 
         [0003]    As the infrastructure of major cities and towns in the developed world age, the sewer systems weaken. Pipe degradation, system blockage, water infiltration, and sewer leakage are major problems that aging sewer systems experience. As these problems persist, the sewer system may eventually experience total failure and entire sections of the sewer system may collapse. As a result, sinkholes may form and sewers may back up into homes and places of business. One method of addressing this critical infrastructure problem is the use of pipe lining techniques to rehabilitate existing sewer systems. 
         [0000]    Cured-in-place pipelining (CIPP) is one such technique that includes rehabilitating an existing sewer system by creating a new pipe within an existing pipe. A liner, impregnated with a resinous material capable of curing and hardening, is inverted or pulled into a damaged pipe. The liner is pressed against the wall of the existing pipe, and the resinous material is allowed to cure and harden. The result is a replacement pipe having the older pipe or “host pipe” on the exterior. The cured-in-place pipe acts to alleviate the problems caused by structural defects and blockages in the existing sewer system. 
         [0004]    The use of steam to cure CIPP liners has become commonplace. Steam is used in conjunction with pressurized air in a bladder to keep the liner pressed against the host pipe and distribute the steam from one end of the liner to other. An exhaust port is typically provided at one end of the bladder to allow for continuous flow-through without deflating the bladder prior to completing the curing process. For example, where a lateral liner is inverted from a main pipe into a lateral pipe and steam is used to cure the resin in the liner, the exhaust port will be at the end of the bladder nearest the house or building connected to the lateral pipe. The steam normally has an unpleasant odor. Thus, when the exhausted steam backs up into the house or building, the occupants are subjected to unpleasant odors. 
         [0005]    Thus, there is a need in the art for a device and method for exhausting steam away from the house or building in communication with the pipeline. 
       SUMMARY 
       [0006]    One aspect of the invention includes a method of exhausting steam in steam curing a cured-in-place liner that avoids directing the steam toward a house or building in communication with a pipeline in need of repair. The method generally includes the use of a liner, a bladder, and an exhaust hose operatively connected to the bladder. A resinous material capable of curing and hardening is applied to the liner. The bladder presses the liner against the pipeline. The end of the steam exhaust hose connected to the bladder is positioned on the interior of the bladder and the opposite end of the steam house is positioned outside the bladder to direct steam away from the house or building. Steam is introduced inside the bladder to assist in curing the resinous material, and the exhaust hose exhausts steam outside of the bladder and away from the house or building in communication with the pipeline. 
         [0007]    Another aspect of the invention includes an apparatus for repairing a damaged section of a pipeline. The apparatus generally includes a bladder, a liner and an exhaust hose. A closed end of the bladder is operatively connected to one end of the exhaust hose. With inversion of the liner and bladder into the pipeline, the end of the exhaust hose connected to the bladder is disposed within the bladder and extends toward the opposite end of the bladder. 
         [0008]    Another aspect of the invention includes a method of exhausting steam in steam curing a cured-in-place liner assembly disposed at the junction between a main and lateral sewer pipe. In steam curing the liner assembly, an exhaust hose directs steam through away from the house or building in communication therewith. In one embodiment the steam is exhausted into the main pipe. In alternate embodiments the steam is exhausted into the lateral pipe or a cleanout pipe. 
         [0009]    Yet another aspect of the invention includes an apparatus for repairing the junction between a main sewer pipe and lateral sewer pipe that includes an exhaust hose to effectively exhaust steam in a steam curing process as described above. 
         [0010]    These and other aspects of the invention will be illustrated in exemplary embodiments described and shown herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view of an embodiment of the invention. 
           [0012]      FIG. 2  is a section view of an embodiment of the invention positioned in a pipe system before inversion. 
           [0013]      FIG. 3  is a section view of an embodiment of the invention positioned in a pipe system after inversion. 
           [0014]      FIG. 4  is a perspective view of an embodiment of the invention. 
           [0015]      FIG. 5  is a section view of an embodiment of the invention positioned in a pipe system before inversion. 
           [0016]      FIG. 6  is a section view of an embodiment of the invention positioned in a pipe system after inversion. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0017]    Referring to  FIGS. 1-3 , a repair assembly is generally designated by the numeral  10 . Repair assembly  10  includes a launcher device  12  having mounted thereto a liner assembly  14 . In one embodiment the liner assembly  14  is an elongated tube adapted to line the inside of a single length of pipe. In alternate embodiments, a T-shaped or Y-shaped liner assembly  14  may be used to line the intersection of two pipes, such as a main pipe  50  and a lateral pipe  52 . Repair assembly  10  also houses a bladder assembly  16 , which may be an elongated tube adapted be positioned inside the liner assembly  14  used to line a single length of pipe. Alternatively, the bladder assembly  16  may be a T-shaped or Y-shaped bladder assembly  16 . T-shaped or Y-shaped bladder tube assembly  16  includes a main bladder tube  34  and a lateral bladder tube  36 . Similarly, the T-shaped or Y-shaped liner assembly  14  includes a main liner tube  38  and a lateral liner tube  40 . The bladder assembly  16  is fitted on the interior of the liner assembly  14 . In the particular configuration shown in  FIGS. 1-3 , the liner assembly  14  and bladder assembly  16  are T-shaped, but they can also be single tubes to line a single pipe or a Y-shaped to accommodate a lateral pipe that intersects with a main pipe at an oblique angle. 
         [0018]    Launcher device  12  includes side walls  18 , a first end  20  and an opposite end wall  22 . The first end  20  includes an aperture  24  through which an exhaust hose  26  extends. A first end of the exhaust hose  26  is connected to an inversion rope  27  and a second end of the exhaust hose  26  is connected to a closed bladder tube end  28  or operatively connected to the bladder tube end  28  through a second inversion rope  25 , B-ring, or other connecting means ( FIG. 3 ). In one embodiment the exhaust hose  26  is inserted through the aperture  24  before being connected to the closed bladder tube end  28 . Also extending through first end  20  of the launcher device  12  is an air inlet port  30  and a back pressure port. The air inlet port  30  is connected to a source of pressurized air (not shown) via an air hose  32 . The back pressure port and associated back pressure hose and pressure gauge can be used to monitor the static pressure when pressurized air is provided to the launcher cavity  48 . 
         [0019]    As can be seen in  FIG. 1 , the main liner tube  38  is comprised of what is initially a flat sheet of material which is wrapped around the outside of the main bladder tube  34  and the launcher device  12 . The main liner tube  38  includes overlapping edges  42 ,  44 . The launcher device  12  includes a launcher device opening  46 , and the lateral liner tube  40  is contained within the launcher device cavity  48  as shown in  FIG. 2 . Similarly, the lateral bladder tube  36  is contained within the launcher cavity  48  and surrounds the lateral liner tube  40 . Both the main liner tube  38  and the lateral liner tube  40  are comprised of a felt layer, which is the lining surface that contacts the interior surface of the host pipe, and a polymer coating is on the opposite surface. A resinous material capable of curing and hardening is applied to the felt layer of the main liner tube  38  and the lateral liner tube  40  using a vacuum impregnation process, as is known in the art, preferably prior to loading the liner assembly  14  on the launcher device  12 . 
         [0020]    As described above, the main portion of the liner assembly  14  is preferably formed as a tube. However the main liner member can be sized so that it only engages a portion of the cylindrical main pipe  50 . 
         [0021]      FIGS. 2 and 3  show the repair assembly  10  within a main pipe  50  which is connected to a lateral pipe  52 . The damaged portion  54  is shown needing repair. Ground water from outside the lateral pipe  52  and the main pipe  50  will seep through the damaged portion  54  and enter the interior of the main pipe  50  and the lateral pipe  52 . 
         [0022]    To help prevent this seepage of ground water, some embodiments include a gasket  56  which can be positioned about a portion of the liner assembly  14 . The gasket  56  includes a tubular portion  60  and a flange portion  58  that extends outwardly about the periphery of one end of the tubular portion  60 . The flange portion  58  of the gasket  56  is preferably attached to the main liner tube  38  around the juncture between the main liner tube  38  and the lateral liner tube  40  so as to maintain the gasket  56  in proper position as the repair assembly  10  is positioned for operation. The gasket  56  is preferably made of a hydrophilic material capable of swelling in response to being exposed to water or other liquid. However, other materials for the gasket  56  found suitable include neoprene rubber, other similar gasket materials such as urethane or silicone rubber, and like impermeable compressible materials, as disclosed in U.S. Pat. No. 7,975,726, which is incorporated by reference. 
         [0023]      FIG. 2  shows the repair assembly  10  moved within the main pipe  50  adjacent the lateral pipe  52 . The launcher device opening  46  is positioned so that it faces the junction between a lateral pipe  52  and the main pipe  50 . This alignment may be done with a camera (not shown). The lateral bladder tube  36  and the lateral liner tube  40  are contained within the launcher cavity  48 . 
         [0024]    Pressurized air is introduced in the cavity  48  through air hose  32 , urging the liner tube assembly  14  into contact with the interior walls of the main pipe  50  and the lateral pipe  52 . Continued air pressure causes the lateral bladder tube  36  and the lateral liner tube  40  to invert outwardly through the launcher device opening  46  into the lateral pipe  52  from the position shown in  FIG. 2  to the position shown in  FIG. 3 . It should be noted that this inversion process causes the lateral liner tube  40  to be placed on the outside of the bladder tube  36  once the inversion is complete, as shown in  FIG. 3 . In this position, the gasket  56  is positioned between the main liner tube assembly  14  and the interior walls of the main pipe  50  and between the lateral liner tube assembly  16  and the interior walls of the lateral line  52 . 
         [0025]    Pressure within the cavity  48  is maintained until the resinous material cures and hardens. This results in the liner assembly  14  assuming a rigid configuration, forming a lining to the lateral pipe  52  and the main pipe  50 . To activate and accelerate the curing process, steam combined with pressurized air is introduced into the system through the air inlet port  30 . The pressurized steam passes through the launcher device  22  and into the inflated bladder assembly  16 . The resinous material is exposed to heat from the steam. The steam is made from a boiler positioned above ground, as is known in the art. 
         [0026]    To provide a sufficient amount of steam and maintain the appropriate temperature for curing, the pressurized steam displaces air in the system by exhausting the air through the exhaust hose  26 . Eventually steam will reach the end of the first end of the exhaust hose near the closed end of the lateral bladder tube  36 . As pressurized steam continues to be supplied to the system, a portion of the steam will pass through the exhaust hose  26  which has an opening near each end. In the embodiment shown, the second end of the exhaust hose  26  is positioned outside the bladder tube  36  in the main pipe  50 . The exhausted steam condenses and flows downstream in the main pipe  50 . In another embodiment the liner and bladder are inverted from a cleanout pipe into the lateral pipe  52  toward the main pipe  50 . In this alternate embodiment the second end of the exhaust hose  26  extends into a cleanout pipe. 
         [0027]    The exhaust hose  26  is preferably made from a high-pressure/high-temperature hose, such as commonly found on the air brake system of a semi-tractor trailer. Such a hose can withstand the temperatures and pressures of the application with a minimal wall thickness. In one embodiment, at each end of the exhaust hose  26 , a ring is welded onto a hollow hose barb that is clamped onto the hose. An inversion rope  25  secures one end of the exhaust hose  26  to the closed end of the bladder. Alternatively, the exhaust hose  26  can be directly connected the closed end of the lateral bladder  36 . A separate inversion rope  27  connects the opposite end of the exhaust hose  26  with a hose reel above ground (not shown). 
         [0028]    In one embodiment, one end of the exhaust hose  26  is positioned near the closed end of the lateral bladder tube  36 . In this configuration, the steam must travel to the far end of the inverted bladder assembly  14  before it can enter the exhaust hose  26  and be exhausted out the opposite end of exhaust hose  26  disposed outside the bladder assembly  14 , such as in the main pipe  50 . This helps ensure that heat from the steam is supplied to the resinous material in both the main liner member  38  and the length of the lateral liner tube  36 . 
         [0029]    The exhaust hose  26 , in its preferred form, provides several functions. First, the exhausts hose  26  effectively exhausts steam into the main pipe  50 . As such, the exhausted steam may be directed away from the house or building in communication with the lateral pipe  52  and thus not subjecting the occupants to unpleasant odors from the steam. Further, the exhaust hose  26  is substituted for a portion of the inversion rope  27 . An inversion rope  27 , as is known in the art, is used to help control the rate at which the liner tube  36  inverts into the host pipe. Additionally, the same inversion rope  27  can be used to remove the bladder  36  from the pipe. An operator or hose reel pulls on the inversion rope  27  to peal the lateral bladder tube  36  away from the lateral liner tube  40  and reinvert it back into the launcher device  12  and/or lay flat hose  21  (as described below). As shown above, the exhaust hose  26  in combination with the inversion ropes  25  and  27  provide the same function. This is one embodiment, and it can be appreciated that a separate inversion rope  27  could also be used that does not rely on the exhaust hose  26 . 
         [0030]    Use of the exhaust hose  26  is not limited to CIPP applications where the juncture between two pipes is being repaired. For example, those skilled in the art having the benefit of this disclosure will appreciate that the exhaust hose  26  could be used in lining just a portion of a lateral pipe  52 . 
         [0031]      FIGS. 4, 5, and 6  illustrate a version of the present invention wherein a lateral liner tube  40  and lateral bladder tube  36  are loaded in a launcher device  12  with a lay flat hose  21  extension. The lay flat hose  21  is fluidly connected to the first end  20  of the launcher device  12 . The opposite end of the lay flat hose  21  is connected to an end cap  23 . The lay flat hose  21  provides for the storage, positioning, and application of pressurized fluid to an extended portion of the liner assembly  14 . The lay flat hose  21 , end cap  23 , and launcher device  12  form a launcher cavity  48 . The end cap  23  includes an aperture  24  through which an exhaust hose  26  extends. A first end of the exhaust hose  26  is connected to an inversion rope  27 . A second end of the exhaust hose  26  is directly connected to a closed bladder tube end  28  or operatively connected through a second inversion rope  25 , d-ring, or other connecting means ( FIG. 5 ). Also extending through end cap  23  is an air inlet port  30  and a back pressure port  31 . The air inlet port  30  is connected to a source of pressurized air (not shown) via an air hose  32 . The back pressure port  31  and associated back pressure hose  33  and pressure gauge (not shown) can be used to monitor the static pressure between the lay flat hose  21  and the bladder assembly  16  when pressurized air is provided to the launcher cavity  48 . 
         [0032]    Similar to the description of the embodiment shown in  FIGS. 1-3 , one end of the exhaust hose  26  is secured near the closed end of the bladder tube  36  with an inversion rope  27 . Once the lateral liner tube  36  and lateral bladder tube  40  are inverted into the lateral pipe  52  (see  FIG. 6 ), the steam curing process begins as previously described. Steam in the internal cavity of the lay flat hose  21  and/or launcher device  12  eventually reaches and enters a first opening in the first end of exhaust hose  26  near the closed end of the bladder tube  36  and passes through the exhaust hose  26  and out a second opening in the exhaust hose  26  near the second (opposite) end. This second end of the exhaust hose  26  may extend in a direction away from the house or building in communication with the lateral pipe  52  and may be positioned outside the launcher device  12  and/or lay flat hose  21 . In the embodiment shown, the second end of the exhaust hose  26  is positioned outside the bladder tube  36  in the main pipe  50 . The exhausted steam condenses and flows downstream in the main pipe  50 . In another embodiment the liner and bladder are inverted from a cleanout pipe into the lateral pipe  52  toward the main pipe  50 . In this alternate embodiment the second end of the exhaust hose  26  extends into a cleanout pipe. 
         [0033]    The exhaust hose  26  could also be used in inversion-type applications without a bladder. Here the impermeable coating on the liner assembly  14  would allow the liner to invert with air pressure. In this embodiment, the first end of the exhaust hose  26  is attached to a portion of the liner assembly  14 . The exhaust hose  26  extends through the aperture  24  in the launcher device  12  and/or aperture  24  in the lay flat hose  21  so the second end of the exhaust hose  26  is outside of the liner assembly  14  and preferably outside of the launcher device  12  and/or lay flat hose  21 . U.S. Pat. No. 7,845,372 filed Mar. 30, 2007 describes such a bladderless application and is incorporated herein by reference. 
         [0034]    While the preferred apparatus and methods for exhausting steam described are intended for use with an inversion-type application, those skilled in the art will appreciate that the exhaust hose  26  can also be used in pull-in-place applications. The exhaust hose  26  would preferably be positioned near one end of the bladder and exhaust the steam out through the other end of the bladder. 
         [0035]    The invention has been shown and described above with reference to the preferred embodiments, and it is understood that many modifications, substitutions, and additional may be made which are within the intended spirit and scope of the invention.