Insulated pipe and method for preparing same

Abstract

The invention provides an insulated pipe-in-pipe assembly comprising (a) at least one inner pipe, (b) an outer pipe disposed around the at least one inner pipe so as to create an annular space between the outer and inner pipes, (c) porous, resilient, compressible material disposed in the annular space, and (d) a remnant of a container that previously was positioned in the annular space and previously held the compressible material in a volume less than the volume of the compressible material in the annular space. The invention also provides a method for making such an insulated pipe-in-pipe assembly.

1 . A method of preparing an insulated pipe-in-pipe assembly, which method comprises: 
 (i) providing an assembly comprising: 
 (a) at least one inner pipe,  
 (b) an outer pipe that is positioned around the at least one inner pipe so as to create an annular space between the exterior surface of the at least one inner pipe and the interior surface of the outer pipe, and  
 (c) at least one container comprising porous, resilient, volumetrically compressible material, wherein the compressible material is restrained within the container and has a first volume, wherein the first volume of the compressible material is less than the unrestrained volume of the compressible material, and wherein the at least one container is disposed in the annular space, and  
   (ii) altering the at least one container to reduce the restraint on the compressible material to increase the volume of the compressible material to a second volume that is greater than the first volume, thereby forming an insulated pipe-in-pipe assembly.    
   
   
       2 . The method of  claim 1 , wherein the method further comprises sealing each end of the pipe-in-pipe assembly so as to fully enclose the annular space.  
   
   
       3 . The method of  claim 1 , wherein the compressible material at the second volume substantially fills the annular space.  
   
   
       4 . The method of  claim 3 , wherein the compressible material at the second volume is under restraint, and wherein the unrestrained volume of the compressible material within the annular space is greater than the volume of the annular space.  
   
   
       5 . The method of  claim 4 , wherein the unrestrained volume of the compressible material within the annular space is about 1% or more greater than the volume of the annular space.  
   
   
       6 . The method of  claim 1 , wherein the compressible material is a hydrophobic material, aerogel, silica aerogel, nanoporous silica, or blanket comprising fibers.  
   
   
       7 . The method of  claim 1 , wherein the compressible material comprises particles having an average particle size of about 0.1 to about 5 mm.  
   
   
       8 . The method of  claim 6 , wherein the blanket has a lofty fibrous structure.  
   
   
       9 . The method of  claim 1 , wherein the compressible material further comprises an opacifier selected from the group consisting of carbon black, titanium dioxide, zirconium silicate, and mixtures thereof.  
   
   
       10 . The method of  claim 1 , wherein the container comprises a film comprised of a metal, a polymer, a copolymer, a fabric, or a combination thereof.  
   
   
       11 . The method of  claim 1 , wherein altering the at least one container comprises breaching the at least one container.  
   
   
       12 . The method of  claim 11 , wherein the breaching of the at least one container is accomplished by heating, electrical resistive heating mechanical rupture, irradiation with an incident beam of radiation, application of a pressure differential, chemical means, or biochemical means.  
   
   
       13 . The method of  claim 1 , which method further comprises positioning additional insulation material in the annular space prior to altering the at least one container.  
   
   
       14 . The method of  claim 13 , wherein the additional insulation material comprises a compressible material.  
   
   
       15 . The method of  claim 14 , wherein the additional insulation material is a blanket comprising a material having a lofty fibrous structure and an aerogel.  
   
   
       16 . The method of  claim 1 , wherein the compressible material is a means for transferring one or more of longitudinal or radial forces between the inner and outer pipes.  
   
   
       17 . The method of  claim 1 , wherein one or more of the inner pipe and the outer pipe made of a flexible material.  
   
   
       18 . The method of  claim 1 , wherein the container is an elongate arched container, and wherein the elongate arched container is coextensive with the exterior surface of the inner pipe for a length of the inner pipe.  
   
   
       19 . The method of  claim 1 , further comprising providing a spacer and positioning the spacer in the annular space.  
   
   
       20 . The method of  claim 1 , wherein the number of spacers utilized in the insulated pipe-in-pipe assembly is less than the number that would be otherwise required in a pipe-in-pipe assembly produced using another method.  
   
   
       21 . The method of  claim 1 , wherein no spacers are present in the annular space.  
   
   
       22 . The method of  claim 1 , wherein the annular space, upon being fully enclosed, is at a pressure selected from the group consisting of substantially atmospheric pressure, below atmospheric pressure and greater than atmospheric pressure.  
   
   
       23 . The method of  claim 1 , wherein the container is a sealed container, the compressible material in the at least one container at the first volume is under a reduced pressure that is less than atmospheric pressure, the annular space has a pressure greater than the reduced pressure within the at least one container, and the altering of the at least one container comprises equalizing the pressure in the at least one container with the pressure of the annular space to increase the volume of the compressible material to the second volume.  
   
   
       24 . The method of  claim 23 , wherein the reduced pressure within the at least one container is about 0.1 kPa to about 100 kPa.  
   
   
       25 . The method of  claim 1 , further comprising the step of adding at least one additional outer pipe, and wherein an additional annular space is present between the exterior surface of the outer pipe and the interior surface of the additional outer pipe, and wherein the additional annular space is occupied by a material selected from the group consisting of: air; porous, resilient, volumetrically compressible material; aerogel; blankets; fibers; blankets containing aerogel; polyurethane foam or glass beads  
   
   
       26 . An insulated pipe-in-pipe assembly prepared in accordance with the method of  claim 1 .  
   
   
       27 . An insulated pipe-in-pipe assembly comprising: 
 (a) at least one inner pipe with an exterior surface,    (b) an outer pipe with an interior surface that is disposed around the at least one inner pipe,    (c) an annular space between the interior surface of the outer pipe and the exterior surface of the at least one inner pipe,    (d) a porous, resilient, compressible material disposed in the annular space, and    (e) a remnant of a container that previously was positioned in the annular space and previously held the compressible material in a volume less than the volume of the compressible material in the annular space.    
   
   
       28 . The insulated pipe-in-pipe assembly of  claim 27 , wherein each end of the pipe-in-pipe assembly is sealed so as to fully enclose the annular space.  
   
   
       29 . The insulated pipe-in-pipe assembly of  claim 27 , wherein the compressible material substantially fills the annular space.  
   
   
       30 . The insulated pipe-in-pipe assembly of  claim 27 , wherein the compressible material is under restraint, and wherein the unrestrained volume of the compressible material within the annular space is greater than the volume of the annular space.  
   
   
       31 . The insulated pipe-in-pipe assembly of  claim 27 , wherein the unrestrained volume of the compressible material within the annular space is about 1% or more greater than the volume of the annular space.  
   
   
       32 . The insulated pipe-in-pipe assembly of  claim 27 , wherein the compressible material is hydrophobic materials, aerogel, silica aerogel, nanoporous silica, or blankets comprising fibers.  
   
   
       33 . The insulated pipe-in-pipe assembly of  claim 27 , wherein the compressible material comprises particles having an average particle size of about 0.1 to about 5 mm.  
   
   
       34 . The insulated pipe-in-pipe assembly of  claim 32 , wherein the blanket has a lofty fibrous structure.  
   
   
       35 . The insulated pipe-in-pipe assembly of  claim 27 , wherein the compressible material further comprises an opacifier selected from the group consisting of carbon black, titanium dioxide, zirconium silicate, and mixtures thereof.  
   
   
       36 . The insulated pipe-in-pipe assembly of  claim 27 , wherein the container was comprised of a film comprising a metal, a polymer, a fabric, or a combination thereof.  
   
   
       37 . The insulated pipe-in-pipe assembly of  claim 27 , wherein the insulated pipe-in-pipe assembly further comprises additional insulation material.  
   
   
       38 . The insulated pipe-in-pipe assembly of  claim 27 , wherein the additional insulation material is a blanket comprising a material having a lofty fibrous structure and an aerogel.  
   
   
       39 . The insulated pipe-in-pipe assembly of  claim 27 , wherein the compressible material is a means for transferring longitudinal forces between the inner and outer pipes.  
   
   
       40 . The insulated pipe-in-pipe assembly of  claim 27 , wherein one or more of the inner pipe or the outer pipe is flexible.  
   
   
       41 . The insulated pipe-in-pipe assembly of  claim 27 , further comprising a spacer positioned in the annular space.  
   
   
       42 . The insulated pipe-in-pipe assembly of  claim 27 , wherein no spacers are present in the annular space.  
   
   
       43 . The insulated pipe-in-pipe assembly of  claim 27 , wherein the annular space is at a pressure selected from the group consisting of substantially atmospheric pressure, below atmospheric pressure, or greater than atmospheric pressure.  
   
   
       44 . The insulated pipe-in-pipe assembly of  claim 27 , wherein the compressible material has a thermal conductivity of 20 mW/m·K or less when measured between a surface at about 0° C. and a surface at about 25° C.  
   
   
       45 . An insulated pipe-in-pipe assembly comprising: 
 (a) at least one inner pipe with an exterior surface,    (b) an outer pipe with an interior surface that is disposed around the at least one inner pipe,    (c) an annular space between the interior surface of the outer pipe and the exterior surface of the at least one inner pipe, and    (d) nanoporous silica disposed in the annular space,    wherein the nanoporous silica has a density between 80 kg/m 3  and about 140 kg/m3 and a thermal conductivity of 20 mW/m·K or less when measured between a surface at about 0° C. and a surface at about 25° C.    
   
   
       46 . The insulated pipe-in-pipe assembly of  claim 45 , wherein each end of the pipe-in-pipe assembly is sealed so as to fully enclose the annular space.  
   
   
       47 . The insulated pipe-in-pipe assembly of  claim 45 , wherein the nanoporous silica substantially fills the annular space.  
   
   
       48 . The insulated pipe-in-pipe assembly of  claim 45 , wherein the nanoporous silica is under restraint, and wherein the unrestrained volume of the nanoporous silica within the annular space is greater than the volume of the annular space.  
   
   
       49 . The insulated pipe-in-pipe assembly of  claim 45 , wherein the unrestrained volume of the nanoporous silica within the annular space is about 1% or more greater than the volume of the annular space.  
   
   
       50 . The insulated pipe-in-pipe assembly of  claim 45 , wherein the nanoporous silica is hydrophobic nanoporous silica or silica aerogel.  
   
   
       51 . The insulated pipe-in-pipe assembly of  claim 45 , wherein the nanoporous silica comprises particles having an average particle size of about 0.1 to about 5 mm.  
   
   
       52 . The insulated pipe-in-pipe assembly of  claim 45 , wherein the insulated pipe-in-pipe assembly further comprises an opacifier disposed in the annular space, wherein the opacifier is selected from the group consisting of carbon black, titanium dioxide, zirconium silicate, and mixtures thereof.  
   
   
       53 . The insulated pipe-in-pipe assembly of  claim 45 , wherein the insulated pipe-in-pipe assembly further comprises additional insulation material disposed between the outer surface of the inner pipe and the interior surface of the outer pipe.  
   
   
       54 . The insulated pipe-in-pipe assembly of  claim 53 , wherein the additional insulation material is a blanket comprising a material having a lofty fibrous structure and an aerogel.  
   
   
       55 . The insulated pipe-in-pipe assembly of  claim 45 , wherein the nanoporous silica is a means for transferring longitudinal forces between the inner and outer pipes.  
   
   
       56 . The insulated pipe-in-pipe assembly of  claim 45 , wherein one or more of the inner pipe or the outer pipe is flexible.  
   
   
       57 . The insulated pipe-in-pipe assembly of  claim 45 , further comprising a spacer positioned in the annular space.  
   
   
       58 . The insulated pipe-in-pipe assembly of  claim 45 , wherein no spacers are present in the annular space.  
   
   
       59 . The insulated pipe-in-pipe assembly of  claim 45 , wherein the annular space is at a pressure selected from the group consisting of: substantially atmospheric pressure, below atmospheric pressure and greater than atmospheric pressure.  
   
   
       60 . An insulated pipe-in-pipe system comprising: 
 (a) two insulated pipe-in-pipe assemblies of  claim 45 , wherein the length of the at least one inner pipe is greater than the length of the outer pipe, wherein the opposing ends of the at least one inner pipe extend beyond opposing ends of the outer pipe, and wherein an end of the at least one inner pipe of one of the two insulated pipe-in-pipe assemblies is sealably connected to an end of the at least one inner pipe of the other of the two insulated pipe-in-pipe assemblies so that the inner pipes are abutting and in communication with one another for fluid flow therethrough, and    (b) a sleeve in the form of a tubular structure having a bore which has a size to receive the pipe-in-pipe assemblies, wherein one end of the sleeve is sealably connected to the outer pipe of one of the two insulated pipe-in-pipe assemblies and the other end of the sleeve is sealably connected to the outer pipe of the other of the two insulated pipe-in-pipe assemblies.    
   
   
       61 . The insulated pipe-in-pipe system of  claim 60 , further comprising an insulating material disposed in the space between the sleeve and the inner pipes of the two insulated pipe-in-pipe assemblies.  
   
   
       62 . An insulated pipe-in-pipe assembly comprising: 
 (a) at least one inner pipe with an exterior surface,    (b) an outer pipe with an interior surface that is disposed around the at least one inner pipe,    (c) an annular space between the interior surface of the outer pipe and the exterior surface of the at least one inner pipe,    (d) a container containing compressed porous, resilient, compressible material said container being disposed in the annular space, and    (e) void space between the container and the interior surface of the outer pipe.    
   
   
       63 . The insulated pipe-in-pipe assembly of  claim 62 , further comprising a centralizer or spacer.  
   
   
       64 . The insulated pipe-in-pipe assembly of  claim 62 , wherein the compressible material comprises aerogel.  
   
   
       65 . The insulated pipe-in-pipe assembly of  claim 62 , wherein said container further contains a remnant of a container that previously was positioned in the annular space and previously held the compressible material in a volume less than the volume of the compressible material in the annular space.  
   
   
       66 . An insulated pipe-in-pipe system, comprising an inner pipe, an outer pipe and insulation therebetween, wherein the insulation provides one or more of longitudinal or radial load transfer between the inner pipe and the outer pipe, and wherein the insulation is not adhesively bonded to the inner pipe or the outer pipe.